JPH0363929A - Magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium with excellent durability.

[Prior art and problems to be solved by the invention] Magnetic recording media slide violently against magnetic heads and pads during recording and reproduction, and the magnetic layer is easily abraded, so the magnetic layer has less wear and is highly durable. something is desired.

Therefore, as measures to improve the wear resistance of the magnetic layer, methods such as an internal addition method in which various lubricants are mixed into the magnetic layer, or a top coating method in which a lubricant layer is formed on the surface of the magnetic layer have been used.

Conventionally used lubricants include higher fatty acids and their esters, fatty acid amides, liquid paraffin, and silicone oils.

However, it is currently difficult to say that these lubricants are satisfactory in terms of performance.

[Means to solve the problem]

The present inventor has arrived at the present invention as a result of intensive research in order to obtain a magnetic recording medium that is provided with good lubricity and has significantly improved durability.

That is, the present invention provides a magnetic recording medium having a magnetic layer on a non-magnetic support, wherein the magnetic layer contains a compound represented by the following general formula (1). This is what we provide.

(In the formula, R represents a hydrocarbon group having 11 to 31 carbon atoms.) In the compound represented by the general formula (1) according to the present invention (hereinafter abbreviated as compound (1)), as described above, R
The number of carbon atoms is 11 to 31, preferably 13 to 2, and most preferably 15 to 17.

Further, R may be a straight chain or a branched chain, and further may be saturated or have an unsaturated bond.

In the present invention, the amount of compound (1) added to the magnetic recording medium is 100! preferably 0.05 to 15 parts by weight per part, and optionally in combination with other general purpose lubricants, such as esters such as butyl stearate, fatty acids such as oleic acid, and hydrocarbons such as squalane. May be used.

The compound (1) in the present invention can be used by being mixed into the paint in advance, or by impregnating it into the paint film by applying a solution of a general-purpose solvent such as isopropanol or hexane and drying after forming the magnetic paint film. .

Further, a medium in which a magnetic layer is formed on a non-magnetic support by sputtering or vapor deposition can also be coated and used in the same manner.

The magnetic powder used in the magnetic recording medium of the present invention is fine needle-shaped 7 FezO5+ Fe104. Cro
metal oxides such as w, and also Co-deposited -FezO,,
C.

γ-F processed like doped 1-Pe, O,
ezO, metallic iron powder, barium ferrite in the form of microplates and some of its Fe atoms are Ti, Co, Zn+V,
Magnetic powder substituted with one or more types such as Nb, Co
+Fe-Co+Ultrafine powder of metals or alloys such as Fe-Ni, etc. can be mentioned. Among these, metallic iron powder is particularly unstable chemically, and to improve this, small amounts of nickel, cobalt, titanium, silicon, aluminum, etc. are added in the form of metal atoms, salts, and oxides, or the surface is treated. However, these can also be used. Metallic iron powder may also have a thin oxide film formed on its surface in a weakly oxidizing atmosphere to stabilize it, and metal powder treated in this way can also be used. Further, two or more kinds of the above-mentioned magnetic powders may be mixed and used.

Examples of the binder used in the present invention for dispersing magnetic powder to form a magnetic layer include polyurethane, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyacrylonitrile, nitrile rubber, epoxy resin, Alkyd resin, boria straw, polyacrylic acid ester,
Examples include polymethacrylic acid ester, polyvinyl acetate, polyvinyl butyral, vinylidene chloride, nitrified cotton, maleic acid-modified vinyl chloride/vinyl acetate copolymer, and ethyl cellulose.

These may be used alone or in combination of two or more. Further, in order to adjust the hardness of the resin, a plasticizer or a hardening agent may be added.

In addition to the above-mentioned components, additives such as abrasives and antistatic agents commonly used in this field can be added to the magnetic layer of the magnetic recording medium of the present invention.

In addition, non-magnetic supports used in manufacturing the magnetic recording medium of the present invention include polyesters such as polyethylene terephthalate; polyolefins such as polyethylene and polypropylene; cellulose derivatives such as cellulose triacetate and cellulose diacetate; polycarbonate; Vinyl chloride; polyimide; plastics such as aromatic polyamide; metals such as Al and Cu; and the like are used. The support may be in any form such as a film, tape, sheet, disk, card, or drum, and the surface of the support may be treated with corona discharge, radiation, ultraviolet light, etc., or may be precoated with a suitable resin.

〔Example〕

EXAMPLES The present invention will be explained in more detail below with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Examples 1 to 4 Metallic iron powder 100 parts by weight Vinyl chloride-vinyl acetate copolymerization Polyurethane resin 0 Carbon black (antistatic agent) Crt (h (abrasive) Toluene Methyl ethyl ketone cyclohexanone note) 11 parts by weight 11〃 2 〃 10〃 71〃 71〃 107〃 $1: Union Carbide (product name: VAG) 1 piece 2:
The above-mentioned composition (trade name: N-2301, manufactured by Nippon Polyurethane Co., Ltd.) was mixed in a sand mill for 10 hours, taken out through a filter, and immediately before coating, 4.4 parts by weight of a hardening agent was added and stirred. This paint was applied to both sides of a 32μ thick polyethylene terephthalate film so that the magnetic layer thickness after drying would be 4μ, dried and rolled up. This was calendered and cured, then punched out into a disk shape, and a 2.0% by weight isopropanol solution of the lubricant shown in Table 1 was applied so that the coating amount of the lubricant shown in Table 1 was 600 cm/bot. A sample disk was prepared by applying the same to the sample disk.

Table Comparative Examples 1 to 4 Sample disks were produced in exactly the same manner as Examples 1 to 4, except that various lubricants shown in Table 2 were used instead of the lubricants used in Examples 1 to 4.

Table 2 Table Test Examples To examine the durability of the sample disks obtained in Examples 1 to 4 and Comparative Examples 1 to 4, each sample disk was housed in a shell lined with nonwoven fabric, loaded into a recording and reproducing device, and The head was run continuously on the same track. The circumferential speed at this time is 7 m/sec.

Damage to the magnetic layer of the sample disk after a certain number of baths was visually evaluated. The state with no scratches was rated as ◎, and the following ratings were given as ○, Δ, and × in descending order of the number of scratches.

The results are shown in Table 3.

Claims (1)

[Scope of Claims] 1. A magnetic recording medium having a magnetic layer on a non-magnetic support, characterized in that the magnetic layer contains a compound represented by the following general formula (1). Medium. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (In the formula, R represents a hydrocarbon group having 11 to 31 carbon atoms.)