Abstract A magnetic recording element with a carrier and a magnetic coating which comprises a magnetic pigment dispersed in a binder in which the sulphate ions present on the surface of the pigment particles are bound in the form of a water-insoluble salt, as well as methods of manufacturing the magnetic recording element in which the magnetic pigment or a non-magnetic FeOOH pigment from which the magnetic pigment can be manufactured is treated with an aqueous solution of a water-soluble salt the cations of which form water-insoluble salts with the sulphate ions present on the surface of the pigment particles and the treated pigment is then processed according to known methods to a magnetic recording element or in which the above-mentioned salt is mixed with the ingredients of the magnetic coating and the resulting magnetic coating lacquer is provided on a carrier and dried.
A method of manufacturing a magnetic recording element, comprising a carrier and a magnetic coating provided thereon said magnetic coating comprising magnetizable particles in a binder dissolved in a solvent, characterized in that non-magnetic FeOOH particles are treated with an aqueous solution of a water-soluble salt the cations of which form a water-insoluble salt with sulphate ions present on the surface of the particles, the treated FeOOH particles are converted according to a known method into magnetic Fe or γ-Fe 2 O 3 particles, which particles are then incorporated in a solution of the binder with the possible addition of auxiliary substances, the resulting magnetic coating is provided on a carrier and the solvent for the binder is evaporated.
Claim 2
Independent Claim
119 words
A method of manufacturing a magnetic recording element, comprising a carrier and a magnetic coating provided thereon said magnetic coating comprising magnetizable particles in a binder dissolved in a solvent, characterized in that non-magnetic FeOOH particles are treated with an aqueous solution of a water-soluble salt the cations of which form a water-insoluble salt with sulphate ions present on the surface of the particles, the treated FeOOH particles are converted according to a known method into magnetic Fe or γ-Fe 2 O 3 particles, which particles are then incorporated in a solution of the binder with the possible addition of auxiliary substances, the resulting magnetic coating is provided on a carrier and the solvent for the binder is evaporated.
Claim 3
Dependent Claim
29 words
A method as claimed in claim 1, characterized in that a water-soluble barium salt is used in a quantity from 0.1 to 2 g per 100 g of pigment.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 2, characterized in that barium chloride, barium hydroxide, barium oxide or barium acetate is used.