JPH0317823A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium excellent in wear resistance and durability by incorporating a specified ether compd. into the magnetic layer. CONSTITUTION:An ether compd. expressed by formula I is incorporated into the magnetic layer formed on a nonmagnetic supporting body. (In the formula, R1 is hydrocarbon radical with 4 - 32 carbons and n is 0 or 1). This ether compd. is synthesized from commercial 1,2-epoxyalkane as the source material, and added to the magnetic layer preferably by 0.05 - 15pts.wt. to 100pts.wt. of the magnetic material. And if required, an all-purpose lubricant such as butyl stearate may be used. Thereby, good results can be obtained from a 5,000,000 - pass durability test on this medium such that the magnetic layer is completely free from flaw.

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 are being 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 inventors have arrived at the present invention as a result of intensive research to obtain a magnetic recording medium that is endowed 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, in which the magnetic layer has the following formula (1)
The present invention provides a magnetic recording medium characterized by retaining an ether compound represented by:

(In the formula, R represents a hydrocarbon group having 4 to 32 carbon atoms, and n
represents O or 1. ) In the ether compound represented by the general formula (1) according to the present invention (hereinafter abbreviated as ether compound (1)), R. The carbon number of is 4 to 32, but especially 10 to 24
is preferred. Further, R1 may be linear or branched, and may be saturated or unsaturated.

The ether compound (1) is prepared using a commercially available 1,2-epoxyalkane as a starting material, for example, CA, 67.747456.
(1967), Japanese Unexamined Patent Publication No. 56-39033, etc., by a method similar to the known method.

The amount of the ether compound (1) added to the magnetic recording medium in the present invention is 0.05 to 1 per 100 parts by weight of the magnetic material.
5 parts by weight is preferred. If necessary, it may also 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 (1) in the present invention is 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. be able to.

The same method can also be applied to media in which a magnetic layer is formed on a non-magnetic support by sputtering or vapor deposition.

The magnetic powder used in the magnetic recording medium of the present invention includes fine needle-shaped I FezO. 、． Fei04+ Cr
Metal oxides such as o2, as well as Co-deposited 1-Fe. O
,, processed γ-Fe. such as Co-doped 7-Fe203. 0. , metallic iron powder, platelet-like barium ferrite and some of its Fe atoms are Tt+ Co,
Examples include magnetic powder substituted with one or more of Zn+V and Nb, and ultrafine powder of metal or alloy such as Co+Fe-Co and Fe-Ni. 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 to decompose the 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 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. Additionally, plasticizers and hardeners can be added to adjust the hardness of the resin. In addition to the above-mentioned precepts, 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 CLI; paper, etc. are used. Forms include film, tape, sheet, disk,
Any card, drum, etc. will do. Further, the surface of the support may be treated with corona discharge, radiation, ultraviolet light, etc., or may be coated 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 vinyl chloride-vinyl acetate copolymer 2 liters Polyurethane resin 1 Carbon black (antistatic agent) CrzOi (abrasive) Toluene methyl ethyl ketone cyclohexanone note) 100 parts by weight 11 〃 ll 〃 2 〃 1O 〃 71 〃 7 liters 〃 lO7 〃 $l: Union Carbide Co., Ltd., product name VAGH 4.4 parts by weight 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 added.
A sample disk was prepared in exactly the same manner as Lubricant 4 shown in Table 1. Table 2 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 same The head was run continuously on the trunk. 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 O, Δ, and × in descending order of the number of scratches.

The results are shown in Table 3.

A sample disk was prepared by applying the coating at a coating amount of 600 cm/bore.

Table 1 Comparative Examples 1 to 4 Examples 1 to Table 3 except that various lubricants shown in Table 2 were used instead of the lubricants used in Examples 1 to 4.

Claims (1)

[Claims] 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). Medium. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (In the formula, R_1 represents a hydrocarbon group having 4 to 32 carbon atoms,
n represents 0 or 1. )