JPS5977625A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To provide excellent wear resistance by incorporating perfluoroalkyl acrylate crosslinked with a resin curable by electron ray in and on a magnetic layer formed by dispersing magnetic layer in a binder consisting essentially of the resin curable by electron ray. CONSTITUTION:A magnetic coating consisting essentially of magnetic powder such as Co-contg. iron cxide, CrO2, Co-Ni alloy or the like, a resin curable by electron ray such as acrylic prepolymer, polyester polyurethane or the like and perfluoroalkyl acrylate (PFAA) is coated on a non-magnetic substrate and is dried. An electron ray is irradiated after the PFAA is further coated thereon as it is or in the state of a soln. and drying the same to crosslink and harden the resin curable by electron ray itself in the magnetic layer and to crosslink the same with the PFAA existing in and on the magnetic layer. The wear resistance and lubricity of the PFAA are thus maintained for a long period of time without allowing the PFAA to migrate to the other, whereby a magnetic tape, floppy disc, or the like having excellent wear resistance and durability is obtd.

Description

[Detailed Description of the Invention] Invention i1'? This invention relates to a magnetic recording medium using Ii-ray curable resin and a reduced inder.

A magnetic recording medium is a binding method in which a magnetic layer mainly composed of magnetic powder such as iron oxide powder and polyurethane acrylate resin is provided on a non-magnetic support such as a plastic film. are known.

In addition, when using not only such magnetic recording media but also magnetic recording media (dr') in general, it is necessary to reduce the frictional resistance with the running magnetic field. Magnetism!- also contains various lubricants to improve its properties.

Examples of lubricants include: g-fluoroalkyl polyether, fatty acid ester 1. e. Fluoroalkyl group-containing esters (JP-A-57-44226) and the like are used. However, all of these lubricants have the disadvantage of being subject to gradual deterioration due to microcrags in the magnetic layer.

Objectives of the present invention (ii) Electron beam curability (magnetic recording media using a lubricant/swinder, excellent abrasion resistance without deterioration due to migration etc.) 7 Magnetic material containing a lubricant Provide the recording medium.

-11 The magnetic recording medium of the present invention is a magnetic recording medium in which a magnetic layer mainly composed of magnetic powder and electron beam curable resin/ζ inder is provided on a non-magnetic support. In the middle and 7/or on the surface of the surface, it contains a fluoroalkyl diurete, which is further cross-linked with the front surface, and contains a fluoroalkyl diurete. It's very magnetic.
K magnetic powder used and 1. So the coercive force is about 300~2
, 300 oersted semi-hard magnetic material or hard magnetic material powder, such as iron oxide, O
o-containing iron oxide: 0rO1:Fe.

Fe-Co containing at least one of Ni and On,
Alloys such as Fe-0o-Nl and Nl-Oo: MnB
Examples include powders such as. Furthermore, it also includes those exemplified in Japanese Patent Application Laid-open Nos. 57-3226 and 57-74828. These magnetic powders may be surface-treated with a 7-run coupling agent, a titanium-based coupling agent, an aluminum-based coupling agent, or the like. Also, Sin,
The surface may be treated with pigments such as.

'lh: As the pure hardening resin, a prepolymer or polymer having one or more, preferably two, acryloyl groups and/or methacryloyl groups in the molecule and a molecular weight of about 500 to about 70,000 is used. For example, terminal (meth)acrylomolization in which hydroxyalkyl (meth)acrylate is bonded to the terminal hydroxyl group of polyester/17 urethane or polyether polyurethane via a diisocyanate compound? There is urethane. In addition, electron beam curable +94 resins described in JP-A-52-21035 and JP-A-53-57023 can also be used.

These are used singly or in a mixture of two or more, taking into account the dispersibility of the magnetic powder, the adhesion of the supports, the adhesion with the magnetic powder, the resin properties of the binder, etc.; Plasticity + Iv1 resin, thermosetting (anti-resin, reactive resin, etc. may be used in combination 1. In any case, use of electron beam curable resin -
A suitable amount of magnetic powder is 4 to 0.05 parts by 1 degree per part of magnetic powder.

As perfluoroalkyl acrylates, those having one or more, preferably four, fluoro groups in the ester group of acrylic acid are used. This perfluoroalkyl acrylate is present in magnetic lIl# and/or magnetic l-
Contains electron beam curable resin and crosslinked resin on the surface. How much do you use? Inder 1 part by weight is 90.2 parts by weight ff1
It is lishang.

In addition to the above-mentioned components, additives such as dispersants, lubricants, and abrasives commonly used in this field can be added to the magnetic layer.

As a non-magnetic support, #-polyesters such as t-polyethylene terephthalate;-theriolefins such as lyethylene and polyzoloflene; cellulose derivatives such as cellulose triacetate and cellulose diacetate;-I licasenate; Polyvinyl chloride; polyimide; plastics such as aromatic polyamide; metals such as All and O; 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 sol coated with a suitable resin.

To make the magnetic recording medium of the present invention, a magnetic paint containing magnetic powder, electron beam curable resin, and perfluoroalkyl acrylate as main components is coated on a non-magnetic support and dried. !
If necessary, apply Tsuku-fluoroalkyl acrylate as it is or in the form of a solution, dry it again if necessary, and then irradiate it with an electron beam, or apply magnetic powder and an electron beam on the support. After applying and drying a magnetic paint whose main component is a curable resin, apply l-sofluoroalkyl acrylate as is or in solution form, and if necessary, dry again to form a magnetic layer (as the case may be). A 9-fluoroalkyl acrylate layer may be provided. By this electron beam irradiation, the electron beam curable resin in the magnetic layer itself is crosslinked and cured, and at the same time, it is crosslinked with perfluoroalkyl acrylate present in the magnetic layer and/or on the surface of the magnetic layer,
This improves the wear resistance of the magnetic layer. Note that the electron beam irradiation is performed at an accelerating voltage of 100 to 750 KV, preferably 150 KV.
The absorbed dose is 2-2 using ~300KV electron beam accelerator.
0 Mrad.

The present invention will now be explained by way of examples.

Example Oo containing 1-Fe2O@ (Titan Kogyo Excel 6
000 ) 50 weight 1 part oleic acid oxide
1 part f polyurethane with acrylic double bond introduced 15 parts 1.6-hairsandiol diacrylate 5 parts tridecyl stearate
Double Chapter/Part Carzen Black
2.5 parts by weight toluene
80 heavy T-part methyl ethyl ketone
80 heavy seams*: Adeka New Ace F13-35 (polyester diol,
Tolylene diisocyanate is added to the hydroxyl value 107-117) L7
and 2-hydroxyethyl acrylate.

Dispersing a suitable composition in a Zeel electrician for 40 hours,
Add this to a polyethylene terephthalate film (about 7cm thick).
0 ptal to a thickness of 2-3 μ and heated at approximately 100°C.
It was dried. Then on top of that 011t = 0HOOOO
A 50-methyl ethyl ketone solution of H2(OF4)4F (Viscoat sF, manufactured by Osaka Organic Chemical Industry Co., Ltd.) was applied and dried at room temperature. A magnetic recording medium having a magnetic layer and a 9-fluoroalkyl acrylate layer was prepared.

Meanwhile, for comparison, the above! - A magnetic recording medium was prepared in the same manner except that the fluoroalkyl acrylate solution was not applied and dried.

We punched out each recording medium into a disk shape, set it in a floppy disk drive, drove it on the same track, and compared the surface iii + abrasion resistance based on the durability time. It showed twice the durability time.

Claims (1)

[Claims] 1 Magnetic powder and electron beam curable clear resin on a non-magnetic support.
A magnetic recording medium provided with a magnetic layer containing an inder as a main component, characterized in that the magnetic layer is formed on the surface of the -9 and/or L1 magnetic layer, and further contains the resin cross-linked (-fluoroalkyl acrylate). magnetic recording medium.