The Modification And Application Of Silicone Pressure Sensitive Adhesive

Silicone pressure sensitive adhesives (PSAs) are new promise prospect adhesives, having so good electrical property that can be wildly used in the electrical and electronics industry. With the development of science and technology in recent years, the electrical and electronic equipments are becoming lighter, more powerful and more reliable. All these require the properties of adhesive to be enhanced to meet the increasing performance demands, especially the high heat resistance. Adhesive must have good performance on bondability and electrical property beside the high heat resistance. Silicone PSAs is usually used as 180℃materials, but it should have better performance in theory. Due to the very small size and very big specific surface, nano particle have some special performance, and great success has been made in the modification of polymer. Above all it could be used for the improvement of high heat resistance of silicone PSAs with the help of nano technology.In this paper, the nano-SiO₂ and nano-Al₂O₃ are dealt with siliane coupling agent and ultrasonic. Then mixed it with silicone PSAs evenly, the modified adhesive is used for soft composite material. The effects of different factors on the homodisperse are discussed in this section. The effect of content on the high heat resistance and electric properties are also studied in the work.The result shows that the dealt SiO₂ and Al₂O₃ are evenly mixed into silicone PSAs matrix. The decomposition temperature (Td) of SiO₂ and Al₂O₃ modified adhesives are increased firstly and then decreased with the growth of content below 5.5wt%. When the content of SiO₂ and Al₂O₃ is 4.5wt% and 1.5wt%, the Td of modified adhesives reach their peak, raised 8.32% and 14.02% respectively. The temperature index (T20000) of SiO₂ modified adhesives has the same trend. When the content of SiO₂ is 4.5wt%, the T20000 arrives extreme value more than 196℃. Whereas the Al₂O₃ modified adhesives is increasing when the content of Al₂O₃ below 2.5wt%. Electric breakdown strength of soft composite also increases firstly and then decrease with the increasing content of SiO₂ and Al₂O₃. Both of them reach the top value when the content is 1.5wt%, which increase 16.96% and 15.96% respectively. The volume resistivity of compost is decreased with the growth of the content of nano particle. The test also shows that the soft composite have a good performance on Flame retardant.