JPH0337821A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To form the magnetic recording medium which lessens the wear of a magnetic layer by using a magnetic layer holding an ether compd. consisting of C, H, O, etc., to form the magnetic recording medium having the magnetic layer on a nonmagnetic base. CONSTITUTION:The magnetic layer of the magnetic recording medium having the magnetic layer on the nonmagnetic base holds the ether compd. expressed by formula. In the formula, R1 denotes 4 to 32C alkyl group or 2 to 30C alkoxy group; R2 denotes 1 to 32C alkyl group. Particularly, 10 to 24C alkyl group, or 8 to 22C alkoxy group is more preferable. R1 may be a straight chain or have a branch chain and may further have a satd. or unsatd. bond. R2 is 1 to 32C alkyl group and is above all preferably 1 to 24C alkyl group and may have a straight chain or branch chain or may further have a satd. or unsatd. bond.

Description

DETAILED DESCRIPTION OF THE INVENTION C. Industrial Application Field 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 worn out. 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 adducts, 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 an ether compound represented by the following general formula (1). It provides:

0H (In the formula, R represents an alkyl group having 4 to 32 carbon atoms or an alkoxy group having 2 to 30 carbon atoms, and R2 represents an alkyl group having 1 to 32 carbon atoms.) The above general formula (1) according to the present invention In the ether compound represented by (hereinafter abbreviated as ether compound (1)), R1 is an alkyl group having 4 to 32 carbon atoms or 2 to 3 carbon atoms.
Among them, an alkyl group having 10 to 24 carbon atoms or an alkoxy group having 8 to 22 carbon atoms is preferable. Further, R may be a straight chain or have a branched chain, and further may be saturated or have an unsaturated bond.

R2 is an alkyl group having 1 to 32 carbon atoms, preferably an alkyl group having 1 to 24 carbon atoms, and may be linear or branched, and may be saturated. may also have an unsaturated bond.

The ether compound (1) is prepared by combining the alkyl oxirane or glycidyl ether represented by the following general formula (2) and an alkyl alcohol represented by the following general formula (3) with a suitable catalyst ( For example, NaOCH3, Na0CzHs, (CH3)3COK
It can be obtained by reacting by a known method in the presence of an alkali metal alcoholade such as

The amount of the ether compound (1) added to the magnetic recording medium in the present invention is from 0.05 to 1001i parts of the magnetic material.
15 parts by weight is preferred. Further, if necessary, it may be used 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.

The ether compound ( ) 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 it after forming the magnetic paint film. can.

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 Fe403. Fe, 0. Crux
Metal oxides such as Co-coated 7-Fe203.
C.

γFe processed such as doped 7-FetO
zes, metallic iron powder, barium ferrite in the form of microplates and some of its Pe atoms are Ti, Co+Zn.

Magnetic powder substituted with one or more of V, Nb, etc.
Examples include ultrafine powders of metals or alloys such as Co, Fe-Co+Fe-Ni, and the like. Among these, metallic iron powder is particularly unstable chemically, and in order to improve this, metal atoms such as nickel, cobalt, titanium, silicon, and aluminum are added.
Salts and oxides, which are sometimes added in small amounts or surface treated, 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, polyamide, polyacrylic 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; polyamide; plastics such as aromatic polyamide; metals such as Al and Cu; paper, etc. are used. The form may be a film, tape, sheet, disk, card, drum, etc. Further, 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 copolymer 111 Polyurethane resin TIZ 11 Carbon black (antistatic agent) 2 Crz03 (abrasive) 10
〃 Toluene 71 〃 Methyl ethyl ketone cyclohexanone 71 parts by weight 107 parts by weight Note) *1: Product name VAGH manufactured by Union Carbide Co., Ltd. Book 2: Product name N-2301 manufactured by Nippon Polyurethane Co., Ltd. After mixing the above mixture in a sand mill for 10 hours, filter Immediately before coating, 4.4 parts by weight of a curing 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 disc shape, and a 2.0% by weight isopropanol solution of the lubricant shown in Table 1 was added.
Sample disks were prepared by applying the lubricant shown in Table 1 in an amount of 600 cm/bot.

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 Test Example In order 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/playback device, and loaded into the same track. I ran Hendo continuously on the top. The circumferential speed at this time is 7 m/sec.

After a certain number of passes, the damage to the magnetic layer of the sample disk 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 holds an ether compound represented by the following general formula (1). recoding media. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (In the formula, R_1 represents an alkyl group having 4 to 32 carbon atoms or an alkoxy group having 2 to 30 carbon atoms, and R_2 represents an alkyl group having 1 to 32 carbon atoms. )