JPS5930243A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic tape or the like whose magnetic layer has improved adhesive strength and lubricity by forming a protective layer contg. >=1 kind of lubricant such as a silicone lubricant, a lubricant contg. fluorine or a silicone lubricant contg. fluorine and an adhesion accelerator on a ferromagnetic metal. CONSTITUTION:A magnetic layer 2 is formed on a substrate 1 such as a polyester film by vapor-depositing a ferromagnetic metal, and a protective layer 3 is formed on the layer 2. The layer 3 contains a silicone lubricant such as dimethylpolysiloxane, a lubricant contg. fluorine such as a perfluoroalkyl polymer or a silicone lubricant cong. fluorine such as fluorine modified silicone oil and a carboxylic acid such as salicylic acid, an amine such as 4-ethylpiperazine or an org. phosphate as an adhesion accelerator. A magnetic layer 12, the 1st protective layer 13 contg. only said adhesion accelerator, and the 2nd protective layer 14 contg. said lubricant and adhesion accelerator may be formed successively on a support 11. Thus, a long-lived magnetic tape or the like having a protective layer with improved adhesive strength and lubricity is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium having a protective layer.

Products in which one ferromagnetic metal is attached diagonally or perpendicularly to one substrate have superior coercive force and squareness compared to conventional coating types, and have recently been put into practical use. It's here.

By the way, when a magnetic recording medium such as a magnetic tape is used for running, a protective layer is usually provided on the surface of the magnetic layer because there is a risk that the magnetic head may scratch and damage the magnetic layer.

Such a protective layer is required to have good adhesion to the magnetic layer and to have surface lubricity.

Conventionally, one of the properties was inferior, and as a result, the life of the magnetic recording medium was short.

The present invention aims to improve the above-mentioned drawbacks and provide a magnetic recording medium having sufficient adhesion and lubricity.

In order to achieve the above object, the present invention provides a magnetic recording medium characterized by providing a protective layer containing at least one type of silicone-based, fluorine-based, or silicone-fluorine thread lubricant and an adhesion promoter. It provides:

The present invention provides a magnetic recording medium which is further provided with a first protective layer consisting of an adhesion promoter and a second protective layer consisting of at least one type of fluorine-based or silicone-fluorine thread lubricant. It is something.

Hereinafter, two embodiments of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a substrate made of a polyester film or the like having a thickness of about 10 to 100 μm. 2 is a magnetic layer, which is made of a ferromagnetic metal such as iron or cobalt using a vacuum deposition method, an ion blating method, or a ferromagnetic metal such as iron or cobalt.

These are adhered and laminated by a battering method or the like.

A protective layer 3 is laminated on the magnetic layer 1 and is composed of a lubricant and an adhesion promoter. Namely.

As a silicone lubricant, dimethylborisiloxa/
and their modified oils, among fluorine-based products, such as para-1 fluoroalkyl polymers, polytetrafluoroethylene, and those with fluoroalkyl groups in their side chains.

As the silicon-fluorine, fluorine-modified silicone oil or the like is used. As an adhesion promoter.

Among carboxylic acids, salicylic acid and thiosalicylic acid.

Maleimidopropionic acid and other amines include 4-ethylhyherazine and 4-aminomethylpiperazine.

Cyclohexylamine, etc., organic phosphoric acids such as phosphoric acid ester, phosphonic acid ester
Organic peroxides include alkyl peresters, peroxyesters, silicon peroxides, etc.; organic titanium-based compounds include orthotitanic acid esters, titanium anlates, titanium chelates, etc.; chromium-based compounds include chromium complex salts that combine organic anions, etc. As the silane coupling agent, vinyltriethoxy 7rane, γ-glycidoxyprobyltrimethquine silane, etc. are used.

That is, the protective layer 3 is made of a lubricant and an adhesion promoter, and the adhesion promoter improves the lubricity and the adhesion with the magnetic layer.

Figure 2 shows two types of 40φ AA-8j'-Cu type lubricants: one with a protective layer made of only a conventional lubricant and the other with a protective layer made of the lubricant of the present invention and an adhesion promoter. Using rolls, we showed the changes in each dynamic friction coefficient with respect to rotation time. In both conventional product 13 and product A of the present invention, a silicone-fluorine based lubricant was used, and an organic phosphoric acid based adhesion promoter was used. The passage 2 that is clear from the diagram
In the case of A according to the present invention, the dynamic friction coefficient hardly changes even if the rotation time becomes long, and is approximately 0.23. On the other hand, the initial value of conventional type B is as low as 0.21, but after 100 minutes it is approximately 0.35.

It is clear that the lubricity is about 15 times that of the present invention, and the lubricity is reduced.

FIG. 3 1d shows another embodiment of the invention, substrate 1.
1 and a magnetic layer 12. A first protective layer 13 and a second protective layer 14 are sequentially laminated. In particular, an adhesion promoter is used for the first protective layer 13, and a fluorine-based or silicon-fluorine-based lubricant is used for the second protective layer 14. Conventionally, fluorine-based lubricants have had the disadvantage of poor adhesion to metals and easy peeling, but since the first protective layer 13 made of an adhesion promoter is provided on the base, the sticking force is improved. That is, by providing the first protective layer 13 and the second protective layer 14,
Adhesion is improved, and the second protective layer 14 provides sufficient lubricity.

As described above, according to the present invention, a magnetic recording medium having a protective layer with improved adhesion and lubricity can be obtained.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a graph of changes in the coefficient of dynamic friction when the embodiment of the present invention is slid on a roll, and Fig. 3 is a cross-sectional view of another embodiment of the invention. show. ■, 11...Base, 2.12...
・Magnetic layer. 3... Protective layer, 13... First protective layer. 14...Second protective layer. Patent applicant Hitachi Capacitor Co., Ltd.

Claims (2)

[Claims] (1) A magnetic recording medium in which a magnetic layer made of a ferromagnetic metal and a protective layer are provided on a base, which contains at least one type of silicone-based, fluorine-based, and silicone-fluorine thread lubricant, and an adhesion promoter. A magnetic recording medium comprising a protective layer. (2) In a magnetic recording medium in which a magnetic layer made of a ferromagnetic metal and a protective layer are provided on a base, a first layer made of an adhesion promoter is provided.
A magnetic recording medium comprising a protective layer and a second protective layer made of at least one type of fluorine-based lubricant.