JPH08259976A - Lubricant and magnetic recording medium using the same - Google Patents

Abstract

(57) [Summary] [Purpose] Regardless of high speed, low speed, high load, low load,
It is possible to slide between two solids that are in contact with each other with low friction and low wear, and to obtain an environment-friendly lubricating substance. Further, durability and running property are improved by using this lubricating substance as a lubricant. The purpose is to obtain a magnetic recording medium. [Structure] As the lubricating substance, a triblock body of fluorinated block-non-fluorinated block-fluorinated block, and the non-fluorinated block having a branched or cyclic structure is used. Further, a magnetic layer is provided on one or both surfaces of the non-magnetic support, and the lubricating substance having the above-described structure is present as a lubricant inside or on the surface of the magnetic layer to form a magnetic recording medium.

Description

Detailed Description of the Invention

[0001]

The present invention relates to high speed, low speed, high load,
The present invention relates to a lubricating substance that slides two solids in contact with each other with low friction and low wear regardless of a low load, and a magnetic recording medium using the lubricating substance as a lubricant.

[0002]

2. Description of the Related Art The surface of a solid and a lubricant have been developed for the purpose of sliding the two solids in contact with each other with low friction and low wear so as to prolong the service life of equipment and devices. Especially in the field of office automation equipment, there is a strong demand for size reduction.
Precise mechanism is adopted for sliding parts year by year. In future equipment in which precision parts slide continuously or intermittently in a wide range of environments, friction and wear at the start of sliding, at the time of sliding or at the end of sliding will be reduced more than ever, and load such as motor will be reduced. Need to be lowered.

Hitherto, in a protective lubricant system, a surface layer that is hard and does not easily wear is provided at a sliding portion, and a grease is used as a lubricant.
Semi-solid or liquid lubricants in the form of oil or oil have been used. However, in precision instruments with smoothed contact areas, no matter how high speed, low speed, high load, or low load, a lubricating substance that slides between two solids with low friction and wear can still be obtained. Therefore, it is impossible to avoid the problem that the frictional force suddenly increases suddenly at the time of starting failure or sliding.

For example, in a ferromagnetic metal thin film type magnetic recording medium formed by depositing a ferromagnetic metal or an alloy thereof on a non-magnetic support by vacuum deposition or the like, a coating type magnetic recording medium is used. Compared with this, it is easy to achieve high coercive force and thin film in the magnetic layer, and while it has excellent high-density recording characteristics, it does not use a tough binder resin and the ferromagnetic metal thin film and protective film have good surface activity. However, the friction coefficient between the magnetic head and the magnetic head is large, and the magnetic head is apt to be worn or damaged, resulting in poor durability or running performance.

Therefore, for example, Japanese Patent Laid-Open No. 60-854
27, JP-A-62-236118, JP-A-2-21.
In publications such as 0615, perfluoropolyether
By using various lubricants such as telluride lubricants, fluorinated carboxylic acid type lubricants, and partially fluorinated carboxylic acid type lubricants, these lubricants are allowed to exist on the ferromagnetic metal thin film to improve durability and running. It has been proposed to improve the sex.

Further, even in a coating type magnetic recording medium in which magnetic powder is bound with a resin, the recording density has been increased, and as an excellent lubricant replacing conventional hydrocarbon type lubricants and silicon type lubricants, The use of fluorine-based lubricants as described above is desired.

[0007]

However, even with the above-mentioned fluorine-based lubricant, it cannot be said that the durability and running property of the magnetic recording medium can be improved to a high degree.
In order to include this kind of lubricant in the magnetic layer and to attach it to the surface of the magnetic layer, it is necessary to dissolve this lubricant in a fluorine-based organic solvent and perform operations such as coating, dipping and spraying. . Fluorine-based organic solvents lead to environmental damage such as destruction of the ozone layer, and there are many problems that the cost is high because the solvent is expensive.

In view of the above-mentioned circumstances, the present invention provides a high-speed, low-speed
Regardless of high load or low load, it is possible to obtain a sliding substance with low friction and low wear between two solids that are in contact with each other, and obtain an environment-friendly lubricating substance, and use this lubricating substance as a lubricant. By doing so, it is an object to obtain a magnetic recording medium with highly improved durability and runnability.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object. As a result, when a specific triblock material is used as a fluorine-based lubricant, the lubricant is used as a general-purpose organic solvent. It is possible to perform operations such as coating, dipping and spraying, and to slide between two solids that come into contact with low friction and low wear without causing harmful effects such as environmental damage due to the use of fluorine-based organic solvents. In addition, it was found that a magnetic recording medium with highly improved durability and running property can be obtained when this is used as a lubricant for a magnetic recording medium, and the present invention has been completed. is there.

That is, the first aspect of the present invention is a lubricating substance comprising a triblock of fluorinated blocks-non-fluorinated blocks-fluorinated blocks, wherein the non-fluorinated blocks have a branched or cyclic structure. It is related to. A second aspect of the present invention is a magnetic recording medium having a magnetic layer on one side or both sides of a non-magnetic support, wherein the lubricating substance according to the first aspect is used as a lubricant inside or on the surface of the magnetic layer. The present invention relates to a magnetic recording medium characterized by having.

[0011]

The triblock body used in the present invention has a molecular structure in which the fluorinated blocks are bound to both ends of the non-fluorinated block, and the fluorinated blocks at both ends of the molecule can be used as a general-purpose organic solvent. Hardly dissolves, but since the non-fluorinated block has a branched or cyclic structure and exhibits high solubility in a general-purpose organic solvent, the above-mentioned non-fluorinated block is apparently wide in a general-purpose organic solvent. It is considered that the molecule becomes in a solid state and exhibits sufficient solubility as the whole molecule.

Such a triblock is represented by the following general formula (1); Rf-x-Rh-y-Rf '(1) Rf: Fluorinated block Rh: Non-fluorinated block having a branched or cyclic structure Rf ′: Represented by a fluorinated block, and in this formula, the fluorinated block (Rf,
Rf ') and the non-broken block (Rh) are connected by x,
y is usually an ester bond, an ether bond, an amide bond, a urethane bond or a urea bond, and these bonds x and y may be the same or different.

In this triblock form, the non-fluorinated block (Rh) has a carbon skeleton having a branched or cyclic structure, and the cyclic structure has an aromatic ring such as a benzene ring, a naphthalene ring or an anthracene ring, or a cyclohexane ring. There are such aliphatic rings. It may be a heterocycle containing an element such as oxygen, nitrogen or sulfur in the cyclic structure. The number of carbons is 3 or more, preferably 4 or more, more preferably 6 or more, and the larger the number, the wider the selection range of the organic solvent and the concentration.
It should be up to 000.

Further, a fluorinated block (Rf, Rf ')
May have a linear, branched or cyclic carbon skeleton, the carbon skeleton may be saturated or unsaturated, and only a part of the constituent carbons may be fluorinated. May be In order to obtain the lubricity peculiar to fluorine, the number of carbons to which fluorine is bonded is preferably 4 or more, particularly 6 or more, and the number of carbons to which fluorine is not bonded is 1 to 4, The total number of carbons is 1,00
It should be up to zero. If necessary, a functional group such as a hydroxyl group, a carboxyl group, an amino group, a halogen, a mercapto group, a sulfonic acid group, a phosphoric acid group, or a salt thereof may be bonded to the molecular end of the fluorinated block.

Such a triblock product may be one synthesized by any method. An example of an industrially effective synthetic method is, for example, a non-fluorinated compound having a hydroxyl group, a carboxyl group, an amino group, an isocyanate group, etc. at both ends of the molecule, and an isocyanate group, an amino group at one end of the molecule. , A fluorinated compound having a carboxyl group, a hydroxyl group or the like is used to cause a reaction between the two functional groups to form an ester bond, an ether bond, an amide bond,
There is a method of chemically bonding by a bond such as a urethane bond or a urea bond.

The lubricating substance of the present invention comprises one or more of the above-mentioned triblocks as an active ingredient. When using the lubricating substance, a fatty acid or a metal salt thereof may be used, if necessary. Fatty acid esters, aliphatic amides, aliphatic alcohols, monosulfides, paraffins, silicone compounds, aliphatic and fluorinated esters,
It may be used in a mixed system with other general lubricating substances such as perfluoropolyether and polytetrafluoroethylene.

The magnetic recording medium of the present invention has a magnetic layer on one side or both sides of a non-magnetic support, and a lubricating substance consisting of the triblock body having the above-mentioned constitution as a lubricant is provided inside or on the surface of this magnetic layer. It is characterized by having. Here, in order to provide the above-mentioned lubricating substance inside or on the surface of the magnetic layer, the lubricating substance is dissolved in a general-purpose organic solvent such as hydrocarbon, alcohol, ketone or ether, and the solution is It may be applied or sprayed on the magnetic layer previously formed on the magnetic support and dried, or conversely, the magnetic layer may be dipped in the above solution and dried.

When the magnetic layer is composed of a ferromagnetic metal thin film, a carbon (diamond-like or amorphous-like) film, a silicon oxide film, a chromium oxide film, or other organic compound is formed on the thin film by vacuum deposition, sputtering, plasma or the like. The protective film may be provided. In addition, a protective film containing fluorine, silicon, or the like may be provided. Further, this ferromagnetic metal thin film may have a slight amount of water attached to its surface, or may be coated with a rust preventive such as benzotriazole.

The amount of the lubricating substance deposited on the ferromagnetic metal thin film is preferably in the range of 0.5 to 20 mg / m ² with respect to the thin film surface. If it is too small, it will be difficult to attach it evenly to the thin film surface,
Still durability cannot be improved sufficiently. On the other hand, if the amount is excessive, the magnetic head and the ferromagnetic metal thin film may stick to each other, which is not preferable.

In the coating type magnetic recording medium, coating, spraying,
In addition to adhesion formation by dipping, mix a lubricant into a magnetic paint using a general-purpose organic solvent and apply it to a non-magnetic support to form a lubricant-containing magnetic coating film. May be. In addition, further coating, spraying,
It may be adhered and formed again by dipping or the like, and after the adhesion, excess lubricant or the like may be washed with a solvent. Further, a lubricant may be contained on the opposite side of the magnetic coating film and transferred to the magnetic coating film side. The content of the lubricating substance in the magnetic coating film is preferably 10 to 100 mg / m ² .

In the magnetic recording medium of the present invention, as the non-magnetic support, a plastic such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyvinyl chloride, etc., aluminum alloy, titanium. Alloys and the like are preferably used. The non-magnetic support may be in the form of tape, sheet, disk, card or the like, or may have a projection on its surface.

In a ferromagnetic metal thin film type magnetic recording medium, Co, Ni, F is formed on one surface or both surfaces of the above non-magnetic support.
e, Co-Ni, Co-Cr, Co-P, Co-Ni-
P, Fe-Co-B, Fe-Co-Ni, Co-Ni-
Fe-B, Fe-Ni, Fe-Co, Co-Pt, Co
Various ferromagnetic materials such as -Ni-Pt or those obtained by adding oxygen to these are formed into thin films by methods such as vacuum deposition, ion plating, sputtering and plating. The thickness of the ferromagnetic metal thin film thus formed is
Usually, it is good to be in the range of 0.03 to 1 μm.

In a coating type magnetic recording medium, a magnetic coating material containing magnetic powder and a binder resin is coated on one or both sides of the above non-magnetic support, and the thickness is usually 0.1 to 10 μm.
A magnetic coating film of about m is formed. The magnetic paint may optionally contain various conventionally known compounding agents such as a filler, an antistatic agent, a dispersant, and a colorant.

Magnetic powders include γ-Fe ₂ O ₃ and Fe ₃
O ₄ , iron oxide in an intermediate oxidation state between γ-Fe ₂ O ₃ and Fe ₃ O ₄ , Co-containing γ-Fe ₂ O ₃ , Co-containing γ-Fe ₃
Various conventionally known magnetic properties such as oxide magnetic powders such as O ₄ , CrO ₂ and barium ferrite, metal magnetic powders such as Fe, Co and Fe-Ni-Cr alloys, and nitride magnetic powders such as iron nitride. The powder is widely used. In the acicular magnetic powder, the average particle size (long axis) is usually about 0.2 to 1 μm, and the average axial ratio (average long axis diameter / average short axis diameter) is usually about 5 to 10. In the case of plate-like magnetic powder, the average major axis diameter is usually 0.0
It is preferably about 7 to 0.3 μm.

As the binder resin, for example, vinyl chloride-vinyl acetate copolymer, fibrin resin, polyurethane resin, polyester resin, polyvinyl butyral resin, polyacrylic resin, epoxy resin Any of those generally used as a binder resin for magnetic recording media, such as a phenol resin and a polyisocyanate compound, is preferably used.

In the magnetic recording medium of the present invention in which the magnetic layer is formed only on one side of the non-magnetic support, a back coat layer may be provided on the opposite side. This back coat layer mixes and disperses non-magnetic powder such as carbon black and calcium carbonate with a binder resin such as vinyl chloride-vinyl acetate copolymer, polyurethane resin, fiber resin and organic solvent. Then, a coating material for the back coat layer is prepared, and the coating material is applied to the opposite surface side of the nonmagnetic support and dried to form the coating material.

The lubricating substance of the present invention can be used as a lubricant in various fields in addition to the above-mentioned lubricant for magnetic recording media, and can also be used as a coating resin (anticorrosion lining, non-adhesive coating, weatherproof coating). ), Fiber treatment agent (water repellent, oil repellent treatment), release agent, oil resistant paper, leveling agent, adhesive, fire extinguishing agent, defoaming agent, optical fiber (as sheath component), optical lens, medical polymer material It can also be used for

[0028]

As described above, according to the present invention, by using a fluorine-based lubricating substance composed of a specific triblock body, it is possible to perform operations such as coating, dipping and spraying with a general-purpose organic solvent. Thus, it is possible to provide an environment-friendly lubricating substance which can slide between two solids in contact with each other with low friction and low wear, without causing harmful effects such as environmental destruction due to the use of a fluorine-based organic solvent. Further, by using this as a lubricant for a magnetic recording medium in particular, it is possible to provide a magnetic recording medium with improved durability and runnability.

[0029]

EXAMPLES Next, examples of the present invention will be described to more specifically describe. In the following, "parts" means "parts by weight".

Example 1 2,2,5,5-having carboxyl groups at both ends of the molecule
Tetramethylhexanedicarboxylic acid 0.5 mol and 1H,
To a mixture with 1 mol of 1H-perfluoro-1-octanal, 5 mmol of sulfuric acid was added, and a reaction was carried out at 200 ° C. for 6 hours while separating water produced by a Dean-Stark water separator. Then, it is purified by recrystallization or distillation, and represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCOC (CH ₃ ) ₂ (CH ₂ ) ₂ C (CH ₃ ) ₂ COOCH ₂ (CF ₂ ) ₇ F. The resulting triblock body 1 was obtained, and this was used as a lubricating substance.

Example 2 The reaction was carried out in the same manner as in Example 1 except that 0.5 mol of terephthalic acid was used instead of 2,2,5,5-tetramethylhexanedicarboxylic acid, and the following structural formula: A triblock body 2 represented by F (CF ₂ ) ₇ CH ₂ OCOC ₆ H ₄ COOCH ₂ (CF ₂ ) ₇ F was obtained, which was used as a lubricating substance.

Example 3 The same as Example 1 except that 0.5 mol of 1,4-phenylene diacetate citrate was used in place of 2,2,5,5-tetramethylhexanedicarboxylic acid. The reaction was performed to obtain a triblock body 3 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCOCH ₂ C ₆ H ₄ CH ₂ COOCH ₂ (CF ₂ ) ₇ F, which was used as a lubricating substance.

Example 4 Reaction was carried out in the same manner as in Example 1 except that 0.5 mol of 4,4'-biphenyldicarboxylic acid was used instead of 2,2,5,5-tetramethylhexanedicarboxylic acid. Then, a triblock body 4 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCOC ₆ H ₄ C ₆ H ₄ COOCH ₂ (CF ₂ ) ₇ F was obtained, and this was used as a lubricating substance.

Example 5 The same as Example 1 except that 0.5 mol of 4,4'-oxybisbenzoic acid hydrate was used in place of 2,2,5,5-tetramethylhexanedicarboxylic acid. The reaction was performed to obtain a triblock body 5 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCOC ₆ H ₄ OC ₆ H ₄ COOCH ₂ (CF ₂ ) ₇ F, which was used as a lubricating substance.

Example 6 Example 1 was repeated except that 2,2,5,5-tetramethylhexanedicarboxylic acid was replaced with 0.5 mol of 2,2-bis (4-carboxyphenyl) propane. A similar reaction is performed to obtain a triblock body 6 represented by the following structural formula; F (CF ₂ ) ₇ CH ₂ OCOC ₆ H ₄ C (CH ₃ ) ₂ C ₆ H ₄ COOCH ₂ (CF ₂ ) ₇ F, This was used as a lubricating substance.

Example 7 Except that 0.5 mol of benzylmalonic acid was used in place of 2,2,5,5-tetramethylhexanedicarboxylic acid.
By reacting in the same manner as in Example 1, a triblock body 7 represented by the following structural formula: C ₆ H ₅ CH ₂ CH [COOCH ₂ (CF ₂ ) ₇ F] ₂ was obtained, and this was used as a lubricating substance.

Example 8 Reaction was carried out in the same manner as in Example 1 except that 0.5 mol of 1,4-cyclohexanedicarboxylic acid was used instead of 2,2,5,5-tetramethylhexanedicarboxylic acid. A triblock body 8 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCOC ₆ H ₁₀ COOCH ₂ (CF ₂ ) ₇ F was obtained, which was used as a lubricating substance.

Example 9 0.5 mol of 1,2,4,5-benzenetetracarboxylic acid dianhydride and 1 mol of 1H, 1H-perfluoro-1-octanal were reacted at 60 ° C. for 6 hours. Let Then, it is purified by recrystallization or distillation to obtain a triblock 9 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OCO (HOOC) C ₆ H ₂ (COOH) COOCH ₂ (CF ₂ ) ₇ F. This was used as a lubricating substance.

Example 10 0.5 mol of 1,4-benzenedibromide and 1H, 1
1 mol of H-perfluoro-1-octanal, 5 mmol of sodium hydroxide and 80 mol of dimethylsulfoxide
0 g was added, and the mixture was reacted at 200 ° C. for 6 hours. After allowing to cool, the mixture was diluted with water to separate an organic layer, which was washed with an aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate, and then the solvent was distilled off. The residue was purified by recrystallization or distillation to obtain a triblock body 10 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OC ₆ H ₄ OCH ₂ (CF ₂ ) ₇ F, which was lubricated. The substance.

Example 11 0.5 mol of 1,4-benzenediisocyanate and 1
1 mol of H, 1H-perfluoro-1-octanal,
The reaction was carried out at 80 ° C for 6 hours. Then, it is purified by recrystallization or distillation to obtain a triblock body 11 represented by the following structural formula: F (CF ₂ ) ₇ CH ₂ OC0NHC ₆ H ₄ NHCOOCH ₂ (CF ₂ ) ₇ F, which is a lubricating substance. And

Example 12 0.5 mol of 1,4-benzenediamine and 2H, 2H-
1.2 moles of perfluorooctanoic acid chloride,
To 1.2 mol of pyridine, 800 g of diethyl ether was added and reacted at 50 ° C. for 12 hours. After washing with an aqueous solution of sodium hydrogencarbonate and water in this order and distilling off diethyl ether, the product was purified by recrystallization or distillation, and the following structural formula: F (CF ₂ ) ₆ CH ₂ C0NHC ₆ H ₄ NHCOCH ₂ (CF ₂ ) A triblock body 12 represented by ₆ F was obtained, which was used as a lubricating substance.

Example 13 To 0.5 mol of hydroquinone and 1 mol of 1H, 1H-perfluoroheptanecarboxylic acid, 5 mmol of sulfuric acid was added to separate water produced by a Dean-Stark water separator. The reaction was carried out at 200 ° C for 6 hours. Then, it is purified by recrystallization or distillation to obtain a triblock body 13 represented by the following structural formula: F (CF ₂ ) ₆ CH ₂ C0OC ₆ H ₄ OCOCH ₂ (CF ₂ ) ₆ F, which is a lubricating substance. And

Comparative Example 1 As a conventionally known fluorine-based lubricant A, a fluorinated ether compound having a carboxyl group at one end of a molecule (carboxyl-modified Galden; average molecular weight 650) was used, and this was used as a lubricating substance. did.

Comparative Example 2 As a conventionally known fluorine-based lubricant B, perfluoro-n-octanoic acid, which is a fluorine compound having a carboxyl group at one end of a molecule, was used, and this was used as a lubricating substance. .

Comparative Example 3 As a conventionally known fluorine-based lubricant C, a fluorine-containing ether compound having ester groups at both ends of the molecule (DEAL manufactured by Montecatini, Italy) was used and lubricated. It was made a sexual substance.

Triblock body 1 of Examples 1 to 13 above
13 to 13 and each of the lubricating substances consisting of the fluorine-based lubricants A to C of Comparative Examples 1 to 3, the solubility in a general-purpose solvent was examined. As a general-purpose solvent, n-hexane is used, and a lubricating substance is added little by little to this solvent and well stirred,
Those that were dissolved by weight% or more were evaluated as ◯, and those that were less than this were evaluated as x. The results are as shown in Table 1 below.

[0047]

[Table 1]

Example 14 A Co-Ni alloy was obliquely vapor-deposited in an oxygen gas atmosphere on a polyethylene terephthalate film having a thickness of 10 μm, and a Co-N film having a thickness of 0.15 μm was formed on the film.
A ferromagnetic metal thin film made of i-O [Co: Ni (weight ratio) = 80: 20] was formed and then cut into a width of 8 mm.

Next, as the lubricant, the lubricating substance consisting of the triblock body 1 obtained in Example 1 was used,
-A lubricant solution was prepared by dissolving it in hexane to a concentration of 0.1% by weight. The above ferromagnetic metal thin film was dipped in this lubricant solution and dried to prepare a video tape having a lubricant film made of the triblock body 1 on the ferromagnetic metal thin film.

Examples 15 to 26 As the lubricant, the triblock body 2 obtained in Examples 2 to 13 was used.
Example 14 except that a lubricating material consisting of
In the same manner as above, the triblock body 2
A video tape having a lubricant coating of 13 was prepared.

Comparative Examples 4 to 6 As the lubricants, the fluorine-based lubricants A to C of Comparative Examples 1 to 3 were used, and these were 1,1,2-trifluoro-1,2,2.
-Dissolved in trichloroethane to a concentration of 0.1% by weight,
Three lubricant solutions were prepared. Example 14 except that the ferromagnetic metal thin film was immersed in this solution and dried.
In the same manner as above, the fluorine-based lubricant A
A video tape having a lubricant coating of C was prepared.

The above Examples 14 to 26 and Comparative Examples 4 to
For each of the 6 video tapes, the still durability is 2
Under 0 ° C. and 50% RH conditions, using an 8 mm VTR (EV-S900 manufactured by Sony Corporation), the reproduction output was 6 compared to the initial value.
The still time until the dB decreased was measured. The results are as shown in Table 2 below.

[0053]

[Table 2]

Example 27 Co was obliquely vapor-deposited in an oxygen gas atmosphere on a polyethylene terephthalate film having a thickness of 6 μm, and a ferromagnetic metal made of Co—O having a thickness of 0.15 μm was formed on the film. A thin film was formed. Next, RF of 13.56MHz
(Radio Frequency) using ethylene as a monomer gas and hydrogen as a carrier gas by a plasma polymerization method to form a DLC (diamond-like carbon) with a thickness of 20 nm on the ferromagnetic metal thin film.
After forming a protective film, it was cut into a width of 8 mm.

Next, as the lubricant, the lubricating substance consisting of the triblock body 1 obtained in Example 1 was used,
-A lubricant solution was prepared by dissolving it in hexane to a concentration of 0.1% by weight. A ferromagnetic metal thin film having the above DLC protective film is dipped in this lubricant solution, dried, and a video tape having a lubricant film made of the triblock body 1 on (the DLC protective film of) the ferromagnetic metal thin film. I made a cup.

Examples 28 to 39 As the lubricant, the triblock body 2 obtained in Examples 2 to 13 was used.
Except that a lubricating substance consisting of ~ 13 is used.
In the same manner as in Example 27, a video tape having a lubricant film made of triblock bodies 2 to 13 on (the DLC protective film of) the ferromagnetic metal thin film was produced.

Comparative Examples 7 to 9 As the lubricants, the fluorine-based lubricants A to C of Comparative Examples 1 to 3 were used.
Three types of lubricant solutions were prepared by dissolving 0.1% by weight concentration in 2-trichloroethane. DLC in this solution
In the same manner as in Example 27, except that the ferromagnetic metal thin film having the protective film was immersed and dried, the fluorine-based lubricants A to C were formed on (the DLC protective film of) the ferromagnetic metal thin film. A video tape with a lubricant coating was made.

Examples 27-39 and Comparative Examples 7-
For each of the 9 video tapes, the still durability (still time) was examined in the same manner as in the above case. The results are as shown in Table 3 below.

[0059]

[Table 3]

Example 40 100 parts of α-Fe magnetic powder (coercive force 1,500 oersted, saturation magnetization 120 emu / g), vinyl chloride-vinyl acetate-vinyl alcohol copolymer (VAG manufactured by UCC)
H) Lubrication consisting of 20 parts, 5 parts of polyfunctional isocyanate compound, 3 parts of carbon black, 3 parts of α-Al ₂ O ₃ powder, 2 parts of myristic acid, and the triblock body 1 obtained in Example 1 as a lubricant. A magnetic paint was prepared by mixing and dispersing a compounding composition consisting of 2.5 parts of the organic substance, 150 parts of cyclohexanone and 130 parts of toluene in a ball mill for 72 hours.

This magnetic paint was dried on a polyethylene terephthalate film having a thickness of 15 μm to a thickness of 5 μm after drying.
m to be coated and dried to form a magnetic coating film,
After calendering, it was cut to a width of 8 mm. Next, the lubricant substance consisting of the triblock body 1 obtained in Example 1 was used as a lubricant, and this was dissolved in n-hexane to a concentration of 0.1% by weight to prepare a lubricant solution. The above magnetic coating film was dipped in a lubricant solution and dried to prepare a video tape.

Examples 41 to 52 The triblock body 2 obtained in Examples 2 to 13 was used as a lubricant to be blended in the magnetic paint and used for preparing the lubricant solution.
Example 40, except that a lubricious material consisting of
In the same manner as described above, 12 kinds of video tapes were produced.

Comparative Examples 10 to 12 The fluorine-based lubricants A to C of Comparative Examples 1 to 3 were used as lubricants to be blended in the magnetic paint and used for preparing the lubricant solution, and Three kinds were prepared in the same manner as in Example 40 except that these lubricants were dissolved in 1,1,2-trifluoro-1,2,2-trichloroethane at a concentration of 0.1% by weight in the preparation. I made a video tape of.

The above Examples 40 to 52 and Comparative Example 10
For each of the video tapes Nos. 12 to 12, the still durability (still time) was examined in the same manner as in the above case. Result is,
The results are shown in Table 4 below.

[0065]

[Table 4]

As is clear from Table 1 above, the lubricous substances of Examples 1 to 13 using the triblock bodies 1 to 13 are compared with the conventional foot lubricants A to C of Comparative Examples 1 to 3. It can be seen that the solubility in general-purpose solvents is excellent. Further, as is clear from Tables 2 to 4, Examples 14 to 13 using the triblock bodies 1 to 13 as the lubricants
The video tape of No. 52 has a longer still time than the video tapes of Comparative Examples 4 to 12 using the conventional foot type lubricants A to C, and in particular, it is a ferromagnetic metal thin film type video tape. It can be seen that the still durability is significantly improved in the video tape in which the DLC protective film is provided on the above thin film, in particular, the above thin film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location C10N 50:08 (72) Inventor Kazushi Miyata 1-88, Tora-ta, Ibaraki-shi, Osaka Hitachi Ma Within Kucsel Co., Ltd.

Claims (8)

[Claims] 1. A lubricious substance comprising a triblock body of fluorinated blocks-non-fluorinated blocks-fluorinated blocks, wherein the non-fluorinated blocks have a branched or cyclic structure. 2. The number of carbon atoms in an unbroken block is 3
The lubricious substance according to claim 1, which is ˜1,000. 3. The number of carbons to which fluorine is bound in the fluorinated block is 4 or more, the number of carbons to which fluorine is not bound is 1 to 4, and the total number of carbons is up to 1,000. Lubricating substance according to 1. 4. The lubricating substance according to claim 1, wherein the fluorinated block and the non-fluorinated block are linked by any one of an ester bond, an ether bond, an amide bond, a urethane bond and a urea bond. . 5. A magnetic recording medium having a magnetic layer on one side or both sides of a non-magnetic support, wherein the lubricating substance according to any one of claims 1 to 4 is used as a lubricant inside or on the surface of the magnetic layer. A magnetic recording medium having. 6. The magnetic layer is composed of a ferromagnetic metal thin film, and the coating amount of the lubricating substance on the surface of the thin film is 0.5 to 20 mg / m ^2.
The magnetic recording medium according to claim 5, wherein 7. The magnetic recording medium according to claim 6, wherein the surface of the ferromagnetic metal thin film has a carbon film, a silicon oxide film or a chromium oxide film. 8. The magnetic recording medium according to claim 5, wherein the magnetic layer comprises a magnetic coating film, and the content of the lubricating substance in the coating film is 10 to 100 mg / m ² .