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Preparation of Magnetic Particles

IP.com Disclosure Number: IPCOM000094336D
Original Publication Date: 1966-Sep-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Haines, RS: AUTHOR

Abstract

Magnetic particles are normally prepared in an aqueous system. Particles produced in an aqueous system must normally be separated and dried before they are distributed in nonaqueous media.

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Preparation of Magnetic Particles

Magnetic particles are normally prepared in an aqueous system. Particles produced in an aqueous system must normally be separated and dried before they are distributed in nonaqueous media.

Magnetic particles prepared from di-alkyl sulfoxide addition products are compatible with most nonaqueous media without being dried. Addition products are prepared by adding a compound of a magnetic metal to a di-alkyl sulfoxide, such as dimethyl sulfoxide. Magnetic particles are then formed by various oxidation, reduction and precipitation steps upon the addition product.

These steps can also be performed after the addition product has been mixed with an aqueous or nonaqueous media. Nonaqueous media for the formation of magnetic particles include wetting agents and binders, for example.

By using a number of metallic compounds to form addition agents with di- alkyl sulfoxide, mixed metallic adducts are formed. For example, a mixture of iron, cobalt and chromium compounds added to di-alkyl sulfoxide forms a mixed metallic adduct of iron-cobalt-chromium.

Particles are also formed by reduction, oxidation or precipitation of the di- alkyl sulfoxide metallic adducts in a gaseous atmosphere. For example, reduction or oxidation is obtained with heat, light or ultrasound.

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