Nitto Boseki Co., Ltd.

Takeo Inoue

Shigeo Yamaguchi

A process for producing spherical inorganic particles which have high flowability, can be incorporated in a high proportion, and are useful as a filler for composite substrates such as printed wiring boards and encapsulating materials. Also provided is a process for producing spherical inorganic particles which have high flowability and can be incorporated in a high proportion and which are useful as a filler for encapsulating materials and give an encapsulating material having high electrical insulating properties. One of the processes for producing spherical inorganic particles comprises: (a1) pulverizing a silicate-containing inorganic material to form a pulverization product; (b1) heating the pulverization product in an atomized state to form the pulverization product into spherical particles; (c1) spraying water over the spherical particles to cool them while maintaining the atomized state of the spherical particles; and (d1) collecting the spherical particles. The other process, which is for producing spherical glass particles, comprises: a pulverization step in which a silicate-containing vitreous material is pulverized to form a pulverization product; an acid treatment step in which the pulverization product is contacted with an acid; and a sphering step in which the pulverization product is heated in a suspended state and formed into spherical particles.

Growing community of inventors

Fukushima, Japan

Takeo Inoue