JPH038112A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium with good lubricating property and largely improved durability by using a specified ether compd. as a lubricant for the magnetic layer. CONSTITUTION:An ether compd. expressed by formula I is used as the lubricant. In the formula, R1 is a hydrocarbon radical with 4 - 32 carbons, R2 and R3 are hydrogen, aliphatic group or aryl group with 1 - 8 carbons. R1 has 4 - 32 carbons, and preferably, 10 - 24 carbons, and it may have a straight chain or branched chains, and may be saturated or unsaturated. R2 and R3 are hydrogen, aliphatic or aryl group with 1 - 8 carbons, and preferably, hydrocarbon radical of 1 - 2 carbons, or hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of 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, pads, etc. during recording and reproduction, and the magnetic layer is easily abraded. 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 inventors have 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 is something to be taught.

(In the formula, R1 represents a hydrocarbon group having 4 to 32 carbon atoms, and R2 and R3 each represent a hydrogen atom, an aliphatic group having 1 to 8 carbon atoms, or an aryl group.) The above general formula (1) according to the present invention In the ether compound represented by (hereinafter abbreviated as ether compound (1)), the carbon number of R8 is 4 to 32, but especially 10 to 24
is preferred. Further, R2 may be a straight chain or have a branched chain, and further may be saturated or unsaturated.

Further, R2 and R3 are each a hydrogen atom, an aliphatic group having 1 to 8 carbon atoms, or an aryl group, and particularly preferably a hydrocarbon group having 1 or 2 carbon atoms or a hydrogen atom.

The ether compound (1) is an epoxy compound represented by the following general formula (2) (for example, AOE manufactured by Daicel Chemical Industries, Ltd.).
X24. AOE X68. AOE YO2, etc.) and an alcohol represented by the following general formula (3) using a known method (Japanese Unexamined Patent Publication No. 63-3
07871) to 4! It can be obtained by reacting with

The alcohol represented by the above general formula (3) is the following - general formula (
4) The ketone or aldehyde represented by the following and glycerin are prepared by a known method] For example, Org, 5ynth, m, 502
(1955)].

Ether compound in the present invention? The amount of I(1) added to the magnetic recording medium is 0.05 to 100 parts by weight 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 (1) in the present invention is used by being mixed into the paint in advance, or by impregnating the paint film by applying a solution of a general-purpose solvent such as isopropanol or hexane after forming the magnetic paint film and drying it. be able to.

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 includes fine needle-shaped T Fezes, FexQa, Cr(
metal oxides such as h, and also Co-deposited 1 FetOs
+C.

Doped y-Fe, 0. γPe processed like
t's, metallic iron powder, platelet-like barium ferrite and some of its Fe atoms are Tll COI Zn+ν,
Magnetic powder substituted with one or more types such as Nb, Co
, Fe--Co, Fe--Ni, and other metal or alloy ultrafine powder. 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, 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, the non-magnetic supports used in producing the 61K 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; Polyvinyl chloride; polyimide; plastics such as aromatic polyamide; metals such as Al and Cu; and the like are used. Forms include film, tape, sheet, disk,
It may be a 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 3 Metallic iron powder 100 parts by weight Vinyl chloride-vinyl acetate copolymer 11 //Polyurethane resin 2 11 //Carbon blank (antistatic agent) 2 CrzO, (Ken L?7F+) 1
0 Tsunotoluene 714
Methyl ethyl ketone 71 no! Cyclohexanone 107 Note) Umbrella 1: Manufactured by Union Calhide, trade name V A G 11
*2: Trade name N-2301 manufactured by Nippon Polyurethane Co., Ltd. The above composition 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 curing agent was added and stirred. This paint was applied onto a 32μ thick polyethylene terephthalate film so that the magnetic layer thickness after drying was 4μ.
It was applied to both sides, dried, and rolled up. This is calendered and hardened, then punched out into a disk shape.
A 2.0% by weight isopropanol solution of the lubricant shown in Table 1 was applied at a coating rate of 600 μ/r.
A sample disk was prepared by applying the coating so as to obtain rr.

Table 1 Sample disks were prepared in exactly the same manner as in Examples 1 to 3, except that the various lubricants shown in Table 2 were used instead of the lubricants used in Examples 1 to 3.

Table 2 Comparative Examples 1 to 4 Test Example 1 In order to examine the durability of the sample disks obtained in Examples 1 to 3 and Comparative Examples 1 to 4, each sample disk was housed in a shell lined with nonwoven fabric, and recorded and reproduced. The device was loaded and the head was run continuously on the same trunk. 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 ○, △, and × in descending order of the number of scratches.

The results are shown in Table 3.

table

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 is a hydrocarbon group having 4 to 32 carbon atoms, R_2
and R_3 each represent a hydrogen atom, an aliphatic group having 1 to 8 carbon atoms, or an aryl group. )