Resin composition comprising two types of particles for acoustic member, ultrasound transducer, ultrasound probe, and ultrasound diagnostic apparatus

An ultrasound transducer used for an ultrasound probe, comprising a backing material and an acoustic matching layer, the acoustic matching layer comprising a cured product of a resin composition,

• the resin composition comprising:
• a thermosetting resin;
• and
• two or more types of particles dispersed in the thermosetting resin,
• the two or more types of particles comprising:
• heavy particles that have a higher density than the thermosetting resin and are particles other than metal particles;
• and
• light particles that have a lower density than the thermosetting resin, and
• a total content of the heavy particles and the light particles relative to an entire volume of the cured product of the resin composition being 10 vol % or more,
• wherein the thermosetting resin consists of an epoxy resin or a urethane resin.