Crazy Chainsaw
Philosopher
- Joined
- Aug 12, 2006
- Messages
- 8,339
http://www.freepatentsonline.com/5356712.html
1. Magnetite particles containing a silicon and/or silicon oxide compound in the interior thereof and also a silicon and/or silicon oxide compound exposed on the surface thereof, said silicon and/or silicon oxide compound on the surface being in an amount of from 0.1 to 2.0% by weight in terms of silicon with respect to the total amount of each of said magnetite particles and the ratio of the amount of the exposed silicon and/or silicon oxide compound to the total amount of said silicon and/or silicon oxide compound in each of said magnetite particles in terms of silicon, being in the range of 0.05 to 0.7, each of said magnetite particles having a shape of a sphere with a maximum diameter and a minimum diameter which satisfy the following relationships: (maximum diameter)/(minimum diameter)=1.00-1.1.
Printing toner.
This invention provides magnetite particles containing a silicon component inside and also a silicon component exposed on the surface of each particle, which are improved in the properties of electrical resistance, remanent magnetization, and fluidity in a well-balanced way and suited for use principally as powdery material for magnetic toner for electrostatic copying and as black pigment powder for coating materials; and also relates to a process for producing the particles.
1. Magnetite particles containing a silicon and/or silicon oxide compound in the interior thereof and also a silicon and/or silicon oxide compound exposed on the surface thereof, said silicon and/or silicon oxide compound on the surface being in an amount of from 0.1 to 2.0% by weight in terms of silicon with respect to the total amount of each of said magnetite particles and the ratio of the amount of the exposed silicon and/or silicon oxide compound to the total amount of said silicon and/or silicon oxide compound in each of said magnetite particles in terms of silicon, being in the range of 0.05 to 0.7, each of said magnetite particles having a shape of a sphere with a maximum diameter and a minimum diameter which satisfy the following relationships: (maximum diameter)/(minimum diameter)=1.00-1.1.
Printing toner.