公开(公告)号：CA1137296A

公开(公告)日：1982-12-14

申请号：CA370485

申请日：1981-02-10

Applicant: IBM

Inventor： HOMOLA ANDREW M ,  RICE SONDRA L

IPC: G11B5/712 ,  C09D5/23 ,  C09D7/12 ,  G11B5/842 ,  H01F1/44 ,  B01J13/00

Abstract: A magnetic dispersion is prepared by adjusting the pH of a mixture containing magnetic particles to a value which results in a positive electrostatic charge on the particles, while a mixture containing colloidal silica particles at the same pH results in negative electrostatic charges on the silica particles. Combining these mixtures causes the silica particles to coat and irreversibly bond to the magnetic particles resulting in better dispersion and less aggregation of the magnetic particles. SA979043