Treatment of high-latency microcapsules containing an aluminium complex with an epoxy-functionalised trialkoxysilane

Abstract

Some aluminium complexes are excellent catalysts of cationic polymerisation and are used for low-temperature and fast-curing adhesive, used in electronic part mounting. Microencapsulation is a suitable technique for getting high latency of the catalysts and long shelf life of the adhesives. For the higher latency in a cycloaliphatic epoxy compound, the microcapsule surface which retained small amount of aluminium complex was coated with epoxy polymer and the effect was examined. From the X-ray photoelectron spectroscopic results, the surface was recognised to be sufficiently coated and the differential scanning calorimetric analyses showed that the coating did not significantly affect the low-temperature and fast-curing properties of adhesive. After storing the mixture of cycloaliphatic epoxy compound, coated microcapsules, triphenylsilanol and silane coupling agent for 48 h at room temperature, the increase in viscosity was only 0.01 Pa s, resulting in the excellent shelf life.

Keywords:

• Aluminium complex
• microcapsule
• epoxides
• silane coupling agent
• cure/hardening

Acknowledgements

The authors would like to thank Yoshihisa Shinya, Shiyuki Kanisawa, Kozaburo Hayashi, Tetsuya Abe and Hiroshi Uchida (Dexerials Co.) for their support of this work and Dr. Makoto Yoshinari for constant encouragement.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.