A silicon foam composition and its preparation method, a silicon foam and an ultrasonic sensor

Abstract

The invention provides a silicon foaming adhesive composition. On the reference of the total mass of the silicon foaming adhesive composition, the composition comprises the following ingredients: 45-80% of polydimethylsiloxane, 10-45% of dimethicone; 5-30% of silicon powder, 0.5-2% of silicone resion, 1-10% of coupling agent; 0.5-3% of 4,4'-oxylbisbenzenesulfonyl hydrazide, 0.5-3% of azodicarbonamide and 0.5-3% of foaming aids. The invention also provides a preparation method of the silicon foaming adhesive composition, and a silicon foaming adhesive prepared by the silicon foaming adhesive composition as well as an ultrasonic sensor containing the silicon foaming adhesive. The ultrasonic sensor of the present invention has the advantages of weak aftershock, low impedance and high sensitivity.

Description

technical field

[0001] The invention relates to a silicon foam glue composition and a preparation method thereof, a silicon foam glue and an ultrasonic sensor. Background technique

[0002] In the ultrasonic sensor, due to the vibration of the piezoelectric element, the bottom surface of the housing vibrates, and the ultrasonic signal is emitted. After hitting an obstacle, it is reflected by the obstacle and returns to the same ultrasonic sensor to detect the obstacle. Under normal circumstances, when the shell of the ultrasonic sensor vibrates, ultrasonic signals will be generated inside the shell, causing internal leakage of vibration energy, and the shell will generate high-order spurious vibration. Even if the piezoelectric element no longer vibrates, the shell vibration will continue, which is called chaos. ring. If the reverberation lasts for a long time, the ultrasonic signal generated by the piezoelectric element due to the reverberation will interfere or even overw...