JPH02263317A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the recording medium which lessens the wear of a magnetic layer and has excellent durability by holding a specific ether compd. in the magnetic layer of 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 I. In the formula I, R1 denotes 2 to 30C hydrocarbon group; R2 and R3 respectively denote a hydrogen atom, 1 to 8C hydrocarbon group or aryl group. Above all, the carbon atoms of R1 are preferably 8 to 22, more preferably 12 to 20. This R1 may be straight chain or may be a branch and may be further satd. or has an unsatd. bond. R2 and R3 are preferably 1 to 2C hydrocarbon group or hydrogen atom. The magnetic recording medium having the excellent durability is obtd. in this way.

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 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 provides:

(However, R1 represents a hydrocarbon group having 2 to 30 carbon atoms, and R2 and !?3 each represent a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, or an aryl group.) In the ether compound represented by
~20 is preferred. This l again? , even if it is a straight chain,
It may have a branch, and may also have a saturated or unsaturated bond.

Further, R2 and R1 are a hydrogen atom, a hydrocarbon 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 obtained by reacting an alkyl halide represented by the following formula (2) with an alcoholade represented by the following formula (3) by a method similar to a known method (for example, JP-A-56-39033). Obtained by forcing.

RIX...(2)
C In the formula, X is a halogen atom, such as C], Br, T,
RI+ RZ, R3 are the same as in formula (1))
The alkyl halide represented by formula (2) is a 897 alcohol and a common halogenating reagent, such as thionyl chloride, phosphorus trichloride, phosphorus pentoxide, phosphorus tribromide, phosphorus pentabromide, mineral acid/hydrogen bromide solution. , red phosphorus/iodine, etc. under normal conditions.

Further, the alcoholade represented by the formula (3) can be prepared using a known method (for example, O
rg, 5ynth, m, 502 (1955)
), the alcohol represented by 2 (5), which can be easily obtained, is reacted with an alkali metal (
(sodium or potassium are suitable) or their hydroxides by conventional methods.

R2-C-Rff...(4)
In the present invention, the amount of the ether compound (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, and fatty acids such as oleic acid.

The ether compound (1) in the present invention can be used by being mixed into the paint in advance, or by impregnating the paint film by applying a solution of isopropyl alcohol and hexane after forming the magnetic paint film and drying.

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

The magnetic powder used in the magnetic recording medium of the present invention includes fine needle-shaped T FezO1+ Pe5Oa, CrO
Metal oxides such as 2, as well as Co-coated −Fe203+
C.

γFe processed like doped γ-FezO+
J3, metallic iron powder, barium ferrite in the form of microplates, and some of its Fe atoms are Ti, Co, and Zn.

Magnetic powder substituted with one or more of V, Nb, etc.
Examples include ultrafine powder of metals or alloys such as Co, Fe-Co, and Fe-Ni. 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; Plastics such as vinyl chloride; polyimide; aromatic polyamide; ^1. Metals such as Cu; etc. 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 4 Metallic iron powder 100 parts by weight Vinyl chloride-vinyl acetate copolymer 11//Polyurethane resin 1//Carbon black (antistatic agent) 2 Crz03 (abrasive)
10〃 Toluene 71〃Methyl ethyl ketone cyclohexanone Note) 71 parts by weight 107〃 Ingredients: Union Carbide Co., Ltd., product name VAGH*2 Nippon Polyurethane Co., Ltd., product name N-2301 After mixing the above composition in a sand mill for 10 hours, it was passed through a filter. It was taken out, and immediately before coating, 4.4 parts by weight of Cured 1 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.
Sample disks were prepared by applying the lubricant shown in Table 1 in an amount of 600 cm/bot.

Table 1 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 1 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 and reproducing device, and the same The head was run continuously on the track. The circumferential speed at this time is 7IIl/sec.

After a certain number of passes, the damage to the magnetic layer of the sample disk was visually evaluated. A state with no scratches was rated as ◎, and evaluations were given as O1△ and × in descending order of the number of scratches.

The results are shown in Table 3.

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) (However, R_1 is a hydrocarbon group with 2 to 30 carbon atoms, R_
2 and R_3 each represent a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, or an aryl group. )