JPS58146028A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent the deterioration due to oxidation, by forming a surface treating film made of a metallic salt or an amine salt of a carboxylic acid or a sulfonic acid on a magnetic metallic film such as a vapor-deposited metallic film. CONSTITUTION:A metallic salt or a primary, secondary or tertiary amine salt of a carboxylic acid such as fatty acid, oxidized paraffin or polyoxyalkylenecarboxylic acid or a known sulfonic acid is stuck to the surface of a magnetic metallic film such as a vapor-deposited metallic film on a substrate by about 1-500mg/m<2> by coating. The metallic salt is calcium salt, zinc salt, barium salt, magnesium salt or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic tapes and other magnetic recording media in which a magnetic metal film, particularly a metal vapor deposited film, is formed on a substrate.

Conventionally, this type of magnetic recording medium has been fabricated by a method such as running a substrate such as a polyester film onto a rotating can through rollers, and then heating and vapor-depositing a highly magnetic metal such as O or Ni onto the substrate under vacuum. It is being However, in conventional magnetic recording media obtained by this method, the metal deposited film is exposed and is therefore susceptible to oxidative deterioration during storage, especially when left in high temperature or high humidity conditions. ,
There was a problem that magnetic properties such as the amount of saturation magnetization deteriorated orally.

As a result of intensive studies to avoid the above-mentioned drawbacks, this invention has been developed by forming a specific surface treatment film on a magnetic metal film such as a metal vapor deposited film, thereby suppressing oxidative deterioration under high temperature and high humidity, and thereby suppressing magnetic deterioration. It has been found that a magnetic recording medium whose characteristics change less over time can be obtained.

That is, the present invention relates to a magnetic recording medium characterized in that a surface treatment film made of a metal salt or amine salt of carboxylic acid or sulfonic acid is provided on a magnetic metal film.

The above metal salts or amine salts used in this invention include fatty acids, paraffin oxides, various carboxylic acids such as polyoxyalkylene carboxylic acids, and metal salts such as calcium salts, zinc salts, barium salts, and magnesium salts of various known sulfonic acids. Salts, primary, secondary, tertiary amine salts, etc. are broadly included. In this invention, it is important to use these metal salts or amine salts; for example, if they are in a free state such as fatty acids, forming a surface treatment film will not have much effect on preventing corrosion of the magnetic metal film. .

The method of forming a surface treatment film from the above compound is not limited, but generally, after forming a magnetic metal film on a substrate, a spraying method or dipping method is used using a solution of the above compound dissolved in an appropriate solvent. All you need to do is surface treatment.

The thickness of the surface treatment film to be formed is 1 to 500 ff+9/d, based on the amount of treated chemical compound (adhered amount).

Preferably, it is about 5 to 100 .mu./d. If the amount of treatment is too large, interlayer adhesion will occur when stored in a wound state, which is not preferable.

The magnetic recording medium of the present invention on which the surface treatment film is formed in this way has very little change in magnetic properties due to the excellent corrosion resistance of the compound.

Examples of the present invention will be described below.

Example 1 On a polyester film with a thickness of 10μ, by a conventional method,
A magnetic metal vapor-deposited film having an o/Ni weight ratio of 9/1 and a coercive force of 670 oersted was formed. In this vapor-deposited film, D
A magnetic tape of the present invention was obtained by surface treatment using a 2% by weight toluene solution of K lanolin soap-CA (calcium lanophosphate manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

Example 2 DK lanolin soap - (Naftlai instead of A) Z
A magnetic tape of the present invention was obtained in the same manner as in Example 1, except that a 2% by weight toluene solution of n (naphthenic acid zinc salt manufactured by Shinto Toyo Co., Ltd.) was used.

Example 3 DK Lanolin Soap - Killesura ()BA instead of CA
A magnetic tape of the present invention was obtained in the same manner as in Example 1, except that a 2% by weight toluene solution of (barium salt of paraffin oxide manufactured by Chrest Chemical Co., Ltd.) was used.

Example 4 DK Lanolin Soap - Kilestride B instead of CA
Example 1 except that a 2% by weight toluene solution of M (magnesium salt of paraffin oxide manufactured by Chrest Chemical Co., Ltd.) was used.
In the same manner as above, a magnetic tape of the present invention was obtained.

Example 5 DK Lanolin Soap-150 Cling instead of CA
A magnetic tape of the present invention was obtained in the same manner as in Example 1, except that a 2% by weight toluene solution of (carboxylic acid amine salt of polyoxyalkylene manufactured by Kisso Yuka Co., Ltd.) was used.

Example 6 This was prepared in the same manner as in Example 1, except that a 2% by weight toluene solution of Kling L (amine salt of aliphatic sulfonic acid manufactured by Kisso Yuka Co., Ltd.) was used instead of DK Lanolin Soap-CA. An inventive magnetic tape was obtained.

Comparative Example 1 Shape the magnetic metal vapor deposited film! Thereafter, a magnetic tape was obtained in the same manner as in Example 1 except that no surface treatment was performed.

Comparative Example 2 A magnetic tape was obtained in the same manner as in Example 1, except that the surface was treated with a 2% by weight toluene solution of lanolin acid instead of DK lanolin soap-CAO.

Comparative Example 3 A magnetic tape was obtained in the same manner as in Example 1, except that the surface was treated with a 2% by weight toluene solution of naphthenic acid instead of DK lanolin soap-CA.

Initial saturation magnetization (Iso) and 60° C., 90% k for each of the magnetic tapes of the above examples and comparative examples.

Saturation magnetization (Ist) after leaving H hinge for two months
From this, the deterioration rate after storage over time ((Iso-1st)/l
5o) The results of determining xlQQ% were as follows.

Deterioration rate Example 1 7% 〃 2 9% 13 9% 〃 4 7% l 5 8% Example 6 8% Comparative example 1 41% l 2 35% 〃 3 37% As is clear from the above results, this It can be seen that the magnetic tape provided with the surface treatment film of the invention has excellent oral characteristics in terms of saturation magnetization.

Claims (1)

[Claims] (1) A magnetic recording medium characterized in that a surface treatment film made of a metal salt or amine salt of carboxylic acid or sulfonic acid is provided on a magnetic metal film.