Preparation of one-component addition-cure liquid silicone rubber coating with enhanced storage stability and bond strength

摘要

It is of great interest and challenge to simultaneously improve the storage stability and bond strength of one-component addition-cure liquid silicone rubber (OLSR) coating for electronic circuit board. In this work, we proposed an efficient approach to address this issue by incorporating both cyano-modification platinum catalyst (CN-PT) and urethane-containing poly(hydromethylsiloxane) (N-PHMS) into OLSR coating using a mechanical mixer. The CN-PT and N-PHMS were synthesized through thermal polymerization reaction and hydrosilylation reaction, respectively. The OLSR coating containing 0.3 phr CN-PT and 3 phr N-PHMS showed the best properties, with a tensile bond strength of 1.63 MPa, a storage period ＞ 180 d at 25 °C, and a curing rate ＜ 2 h at 80 °C. The salt-spray resistance and continuous power-on performance of OLSR coating were also improved, compared with pure OLSR coating. The synergism of CN-Pt and N-PHMS on the enhancement of both the storage stability and bond strength of OLSR coating was also explored. Our findings exhibited great potentials for fabricating OLSR coating with excellent long-term stable service performance including high storage stability and protective ability.