Sealant applied to sealing of underwater optical electronic equipment and preparation method thereof

The invention relates to a sealant applied to sealing of underwater optical electronic equipment and a preparation method thereof, and belongs to the field of sealing materials. A base material of thesealant comprises high-molecular butyl rubber and natural rubber which are combinedly used, and a low radioactive filler, low-molecular polyisobutylene, middle-molecular polyisobutylene, an activator, a mildew inhibitor and a coupling agent are added. With combined use of butyl rubber and natural rubber, not only are the characteristics of good air tightness and water tightness of butyl rubber retained, but also the shortcomings of poor processability, poor vulcanization property and cold flow of butyl rubber are overcome, so that the sealant has the advantages of good air tightness, water tightness, low cold flow property and high strength. The low-molecular polyisobutylene and middle-molecular polyisobutylene as a tackifier and a viscosity regulator have good compatibility with butyl rubber, have no small molec