SU932548A1 - Magnetic suspension for magnetic record carrier sensitive layer - Google Patents

Description

(5Y MAGNETIC SUSPENSION FOR THE WORKING LAYER OF THE CARRIER OF MAGNETIC RECORDING

The invention relates to the field of magnetic recording, in particular to magnetic suspensions for a working layer of a magnetic recording carrier.

A known magnetic suspension for a working layer of a magnetic recording carrier, consisting of magnetic particles of gamma-iron oxide distributed in a binding substance, additives and a solvent. The known suspension makes it possible to ensure the relative simplicity of the process of manufacturing from it a working layer of the magnetic recording carrier l and 2.

A disadvantage of the known magnetic suspension consists in the low wear resistance of the working layer of the magnetic recording carrier made from it.

A known magnetic suspension for a working layer of a magnetic recording carrier, consisting of magnetic particles of gamma-iron oxide distributed in a water-soluble alkyl maleate or glycidyl-containing acrylic copolymer. Ret. Buty lphenol-saline formaldehyde oligomer, dispersing agent, propyl alcohol, triethylamine and water. This magnetic suspension makes it possible to ensure a relatively high wear resistance of the working layer of the GZ magnetic recording medium made from it.

A disadvantage of the known magnetic suspension consists in a significant uneven distribution of the magnetic particles of gamma-iron oxide.

The purpose of the invention is to reduce the non-uniform distribution of the gn-iron oxide particles in magnetic suspension.

Claims (3)

This goal is achieved by the fact that the magnetic suspension for the working layer of the magnetic recording carrier contains as a dispersant a mixture of mono- and di-3 alkyl aryl ethoxyphosphates of the general formula I. (, 0 dHj dbtg o} - P - OK OK g--. .0 2 (O) o (c H2eH20) Jp R. O where Kat is the N. K cations, NH {CiH40HJj; n is the integer 1 - 15; R - -alkyl; R - -alkyl or hydrogen in the following ratio of components, weight: magnetic particles of gamma-iron oxide 29.0 - 31.0; water-soluble alkyl maleate or glycidyl-containing acrylic copolymer 8.0 - 12.0; and -TET .-butylphenol salicylic formaldehyde oligomer 0.7 2.5, a mixture of mono- and dialkyl aryl ethoxy phosphates Oj3 - 0.9, propyl alcohol 10.0 - 0.0, triethylamine 0.5 - and water else. The proposed magnetic suspension consists of magnetic particles gamma- iron oxides, equal but distributed in a water-soluble alkyl maleate acrylic copolymer, L-tert-butylphenol-techsalicyl formaldehyde oligomer, propyl alcohol, triethylamine, water, and a dispersant, in the KsiJecTBe of which it contains a mixture of mono- and dialkylareto-ethoxy-techfexyl, and in a dispersant it contains a mixture of mono- and dialkylareto-ethoxyphrophic-dextraline. , - Р - OK LP to Р OK where Kat is H, K, Na or NHCc H ofOJ cations; n is an integer of 7-15; I R - Cg-C O-alkyl; R. - alkyl or hydrogen The magnetic suspension may contain, by weight: magnetic particles of gamma-iron oxide, alkyl maleic acrylic copolymer 8.0; 84 I-tert.-butylphenol salicyl formaldehyde oligomer 0.7; mixtures of monoyl dialkylaryl ethoxypho sphospat 0.3 propyl alcohol 0,0; triethylamine 0.5 and water 21.5. In this case, the magnetic suspension may, instead of the alkyl maleate acrylic copolymer, contain a glycidyl-containing acrylic copolymer. The proposed magnetic suspension is intended for the manufacture of a working layer of a magnetic recording carrier. In the process of making the working layer, the suspension is applied in the form of a thin film on a non-magnetic base of the magnetic recording medium. After drying, this film forms a working layer of magnetic recording media. The use of the proposed Minimal suspension makes it possible to significantly reduce the uneven distribution of the magnetic particles of gamma-iron oxide, which improves the magnetic properties of the working layer of the magnetic recording carrier. Magnetic suspension for the working layer of the magnetic recording carrier, consisting of magnetic particles of iron gamma oxide distributed in a water-soluble alkyl maleate or glycidyl-containing acrylic copolymer, p-tert.-butylphenol salicylic formaldehyde oligomer, dispersion. a drying substance, propyl alcohol, triethylamine and water, characterized in that, in order to reduce the uneven distribution of magnetic particles of gamma iron oxide, the magnetic suspension contains as a dispersant a mixture of mono- and dialkylaryl ethoxyphosphates of the general formula (O) o (CHg) „ - Р OKet oka O B (U) o (dH, (lHtO) JP) l 1, OKat Jl where Kat - cations H, K, Na or NH (); n - integer 7 - 15; 5 R - Cg-C acid; R is -alkyl or hydrogen, in the following ratio of components, comrade, res.%: Magnetic particles of gamma, ma-iron oxide, 0 alkyl maleinate or glycide and l containing acrylic copolymer 8.0-12.0 p-tert. -butylphenol- "licylformaldehyde oligomer 0.7-2.5 A mixture of mono- and dialkylaryl ethoxyphosphates. 0.3-0.9 "8" Propyl alcohol 10,., 0 Triethylamine 0.5-1.5; Code Rest Sources of information taken into account during the examination 1. Japanese patent IG 17-18572, cl. 102 E 110, May 29; 72. . 2. Japan Patent G 7-280,,. cl. 102 E 110.11, 07.27.72. 3. Japan patent IT 7-27886:. cl. 102 K 110.11, 07.25.72 (prototype).