JP3365790B2 - Magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] This invention relates to a ferromagnetic metal thin film layer.
For more information on magnetic recording media used as recording layers, see
The magnetic recording medium described above has excellent durability and excellent reliability.
Related. [0002] BACKGROUND OF THE INVENTION Generally, ferromagnetic metals or their alloys
Etc. on a non-magnetic support by vacuum evaporation, etc.
The ferromagnetic metal thin film type magnetic recording medium is
The magnetic layer can be made higher coercive force and thinner than a magnetic recording medium.
It is excellent in high recording density characteristics. However, on the other hand,
No binder resin is used, and the surface of the ferromagnetic metal thin film layer is smooth.
The magnetic head that slides during recording and reproduction.
The friction coefficient is large and the ferromagnetic metal thin film layer is worn or damaged.
It is easy to burn and has poor durability and running properties. [0003] For this reason, for example,
-Ter lubricants, carboxylate lubricants, partial lubricants
Lubricants such as fluorinated carboxylic acid ester lubricants
On the conductive metal thin film layer to improve durability and runnability.
Good things are being done. (JP-A-60-85427)
JP-A-62-236118, JP-A-2-2106
No. 15) [0004] SUMMARY OF THE INVENTION
Excellent lubrication when lubricant is present on the ferromagnetic metal thin film layer
Although the effect is exhibited, the same location is slid continuously
As in the case of a still picture on a video tape,
It is still not enough under severe conditions, and still time is extremely
Sufficient reliability cannot be obtained due to shortening. [0005] SUMMARY OF THE INVENTION The present invention relates to this situation.
In view of the above, ferromagnetic gold
General formula on the surface of the metal thin film layer           R₁-COO-R_Two− (CF_Two) N-R_Three-OOC-R_Four Or R ₁ -OOC-R _Two − (CF _Two ) N-R _Three -COO-R _Four [However, R₁And R_FourHas a carbon number3~ 18 hydrocarbons
Group or R_FiveA, R_FiveHas a carbon number2~ 17 hydrocarbons
Group, A is-COOM group (where M is a hydrogen atom or
Potassium atom), amino group or butoxy groupChosen from
Polar functional group, R_TwoAnd R_ThreeHas 0 to 8 carbon atoms
Hydrocarbon groupIs, N is an integer of 2 to 40. ]
Fluorinated alkyl ester compound
Still under severe conditions
Highly reliable ferromagnetic metal thin film type with sufficiently improved durability
A magnetic recording medium is obtained. Alkyl fluoride used in the present invention
As shown in the above general formula,
At least two esters at each end of the fluorinated alkyl chain
A compound having a hydrocarbon chain with a monovalent bond at both ends of the molecule.
The ester bond at the end has the appropriate polarity
Therefore, if it is present on the ferromagnetic metal thin film layer,
Moderate interaction with the membrane layer occurs and is maintained stably
You. [0007] In addition, the alkyl fluoride chain and both ends thereof
By changing the length of the hydrocarbon chain, moderate viscosity
With low viscosity and repeated sliding contact with the magnetic head.
Magnetic head with high viscosity
There is no sticking to. Accordingly, this type of fluorinated alkyl ester
When the compound is present on the surface of the ferromagnetic metal thin film layer,
Withstands strong sliding contact with the head, even under severe operating conditions.
Excellent lubrication effect is fully exhibited, and still durability is enhanced.
Improved in minutes. On the other hand, conventional perfluoropolyethers
Tell-based lubricants have polar hydroxyl groups at the terminal
Polar groups such as carboxyl groups and carboxyl groups are surrounded by fluorine chains
It is easy to have
Has a functional group that is not so high,
It is not stably held on the surface of the magnetic metal thin film layer,
Insufficient and repeated sliding contact with the magnetic head will cause
It disappears and has sufficient still resistance under severe use conditions.
I cannot get longevity. [0010] Such a fluorinated alkyl ester compound
Is a group represented by the general formula₁And R_FourHas a carbon number
3~ 18 hydrocarbon groups or R_FiveA, R_FiveHas a carbon number
2To 17 hydrocarbon groups, A is-COOM group (where M is
Hydrogen atom or alkali metal atom), amino group or
Toxic groupPreferably a polar functional group selected from
No. Further, R_TwoAnd R_ThreeHas 0 to 8 carbon atoms
Hydrocarbon groupAndFurther, n is an integer of 2 to 40.
Preferably, the hydrocarbon group here has a branched chain.
And may have an unsaturated bond.
No. It should be noted that the alkyl fluoride chain in the molecule
If the proportion is less than 30% by weight, the superiority of the elemental fluorine is obtained.
30 lubrication characteristics are not obtained
% Is preferable. The fluorinated alkyl ester compound
IsInsufficient lubrication properties if the molecular weight is too smallBecame
Therefore, it is preferable to have a molecular weight of 500 or more. one
The molecular weightIf too large, the solubility in organic solvents is low.
underAnd have a molecular weight that does not have such a problem.
Is preferred. Such a fluorinated alkyl ester compound
The synthesis method of is not particularly limited, and may be synthesized by any synthesis method.
May be used. For example, an industrially effective synthesis method
And a hydrocarbon compound having a carboxyl group or water
Hydrocarbon compound having acid group and carboxyl at both ends
Fluorinated alkyl ester compounds having a hydroxyl group or a hydroxyl group
The product obtained by performing a normal esterification reaction using
Is preferably used. Also, this type of fluorinated alkyl esterification
Compounds can be used alone or as a mixture of two or more
And various lubricants, such as fatty acids or
Its metal salts, fatty esters, fatty amides, fatty acids
Alcohol, monosulfide, paraffins, silicone
Compounds, esters of aliphatic compounds and fluorine compounds,
Perfluoropolyether, polytetrafluoroethylene
With good compatibility with fine powder of fluororesin such as
You. Such a fluorinated alkyl ester compound
Must be present on the surface of the ferromagnetic metal thin-film layer.
Fluorinated alkyl ester compounds used as fluorine
Dissolves in solvents, hydrocarbon solvents such as tetrahydrofuran
Then, a non-magnetic support such as a polyester film
Spray or spray on the ferromagnetic metal thin film layer formed on
To dry or vice versa.
This is performed by a method such as dipping and drying the film layer. The amount to be deposited is 0.5 to 20 mg / m^TwoWithin the range of
0.5 mg / m^TwoIf less, sometimes
Can not be evenly distributed as
It cannot be improved sufficiently. 20mg on the contrary
/ M^TwoIf more, the ferromagnetic metal thin film layer
It is not preferable because it sticks. At this time, this kind of alkyl fluoride
The ferromagnetic metal thin film layer in which the stele compound is present
A small amount of water may be attached.
Even those coated with rust preventives such as azole rust preventives
Good. In addition, vacuum deposition, sputtering, plasma, etc.
A protective film layer made of an organic compound, carbon, silicon oxide, or the like.
It may be provided on a ferromagnetic metal thin film layer. The ferromagnetic metal thin film layer is formed by vacuum evaporation of a ferromagnetic material.
Dressing, ion plating, sputtering, plating, etc.
On one or both sides of the non-magnetic support by means of
The thickness is in the range of 0.03 to 1 μm.
Preferably, it is within the box. Here, as the ferromagnetic material, Co, Ni,
Fe, 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, C
General materials such as o-Ni-Pt and those obtained by adding oxygen to them
No ferromagnetic materials used to form ferromagnetic metal thin film layers
This is also used. The ferromagnetic metal thin film layer is made of any of these strong magnetic
Although it may be formed using a conductive material, Co-Ni-
Fluoride is applied to the ferromagnetic metal thin film layer formed using O.
The presence of an alkyl ester compound is particularly effective.
The fruit is exerted. Therefore, Co, Ni, and O are the main components.
Is particularly effective for a ferromagnetic metal thin film layer of
Co, Ni and O having a weight ratio of i of 97/3 to 60/40
This is most effective for a ferromagnetic metal thin film layer whose main component is. Such a ferromagnetic metal thin film layer is nonmagnetically supported.
When provided on one side of the body, the back cover
A back coat layer may be provided with a carbon
Lac, non-magnetic powder such as calcium carbonate, binder resin
Mixed with organic solvent and back coat layer
A paint for the back coat layer is prepared on the surface.
The back surface of the non-magnetic support on which the ferromagnetic metal thin film layer is formed
Cloth, formed by drying. As the non-magnetic support, polyethylene
Phthalate, polyethylene naphthalate, polycarbonate
-Plastics such as glass, polyimide, polyvinyl chloride, etc.
Or aluminum alloy, titanium alloy, etc.
The shape of these non-magnetic supports is tape, sheet,
It may be a disc, card, etc.
May be formed. [0024] Next, an embodiment of the present invention will be described. Example 1 Polyethylene terephthalate film with a thickness of 10 μm
Loaded in a vacuum deposition apparatus, oxygen gas pressure 5 × 10^-FiveOf the tour
Under the residual gas pressure, the Co-Ni alloy is heated and evaporated,
Polyethylene terephthalate is continuously deposited at an oblique incidence.
On the film, Co-Ni-O (Co: Ni = 80: 2)
0) to form a ferromagnetic metal thin film layer having a thickness of 0.2 μm
Was. On the other hand, the chemical formula HOCH_Two(CF_Two)₈C
H_TwoFluoride having hydroxyl groups at both ends represented by OH
50 parts by weight of a alkyl compound,n-heptanoic acid110 weight
Parts into a reaction vessel, while bubbling nitrogen through
Reaction at 150 ° C. for 5 hours, represented by the following chemical formula
A fluorinated alkyl ester compound was obtained.           C₆H₁₃COOCH_Two(CF_Two)₈CH_TwoOOCC₆H₁₃ Next, the fluoride thus obtained is obtained.
Dissolve the alkyl ester compound in tetrahydrofuran
0.2% by weight of fluorinated alkyl ester compound
A hydrofuran solution is obtained, and the polyethylene
Co-Ni- formed on a terephthalate film
Immerse the ferromagnetic metal thin film layer consisting of O, dry and adhere
I let you. After that, slit to 8mm width and tape
Was prepared. Embodiment 2 Synthesis of fluorinated alkyl ester compound in Example 1
In the fluorinated alkyl compound used in Example 1,
Alternatively, the chemical formula HOCH_Two(CF_Two)₁₈CH_TwoOH
Fluorinated alkyl compounds having hydroxyl groups at both ends represented by
Except that the same amount of the product was used,
Obtaining a fluorinated alkyl ester compound represented by the chemical formula
Was.           C₆H₁₃COOCH_Two(CF_Two)₁₈CH_TwoOOCC₆H₁₃ Next, the above-mentioned chemical reaction was carried out in the same manner as in Example 1.
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which was used in Example 1
0.2% by weight of the fluorinated alkyl ester compound
Example 1 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 3 Chemical formula HOOC (CF_Two)₈COOH
Fluorinated alkyl compound having a terminal carboxyl group 5
0 parts by weight and 110 parts by weight of isopropyl alcohol
Into a reaction vessel, while bubbling nitrogen through,
The reaction is carried out at 0 ° C for 5 hours.
Thus, an alkylated alkyl ester compound was obtained.(CH _Three ) _Two CHOOC (CF_Two)₈COOCH (CH _Three ) _Two Then, the same procedure as in Example 1
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which was used in Example 1
0.2% by weight of the fluorinated alkyl ester compound
Example 1 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 4 Synthesis of fluorinated alkyl ester compound in Example 3
In the above, the alkyl fluoride compound used in Example 3
Instead, the chemical formula HOOC (CF_Two)₁₈Table by COOH
Alkyl fluorides with carboxyl groups at both ends
The same procedure as in Example 3 was repeated except that the same amount of the compound was used.
A fluorinated alkyl ester compound represented by the chemical formula
Obtained.(CH _Three ) _Two CHOOC (CF_Two)₁₈COOCH (CH _Three ) _Two Then, the same procedure as in Example 3
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 3
0.2% by weight of the fluorinated alkyl ester compound
Example 3 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 5 Synthesis of fluorinated alkyl ester compound in Example 3
Isopropyl alcohol used in Example 3
Instead, use the same amount of 2-butoxyethyl alcohol
Other than the above, the compound was represented by the following chemical formula in the same manner as in Example 3.
Thus, a fluorinated alkyl ester compound was obtained.       C_FourH₉OC_TwoH_FourOOC (CF_Two)₈COOC_TwoH_FourOC_FourH₉ Next, the above-mentioned chemical reaction was carried out in the same manner as in Example 3.
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 3
0.2% by weight of the fluorinated alkyl ester compound
Example 3 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 6 Synthesis of fluorinated alkyl ester compound in Example 5
In the above, the alkyl fluoride compound used in Example 5
Instead, the chemical formula HOOC (CF_Two)₁₈Table by COOH
Alkyl fluorides with carboxyl groups at both ends
The same procedure as in Example 5 was repeated except that the same amount of the compound was used.
A fluorinated alkyl ester compound represented by the chemical formula
Obtained.       C_FourH₉OC_TwoH_FourOOC (CF_Two)₁₈COOC_TwoH_FourOC_FourH₉ Then, the same procedure as described in Example 5
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 5
0.2% by weight of the fluorinated alkyl ester compound
Example 5 except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 7 Synthesis of fluorinated alkyl ester compound in Example 3
Isopropyl alcohol used in Example 3
Example 2 except that the same amount of ricinoleic acid was used instead of
Alkyl fluoride represented by the following chemical formula in the same manner as in 3.
An ester compound was obtained.           HOOCC₁₇H ₃₂ OOC (CF_Two)₈COOC₁₇H ₃₂ COOH Then, the same procedure as in Example 3
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 3
0.2% by weight of the fluorinated alkyl ester compound
Example 3 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Embodiment 8 Synthesis of fluorinated alkyl ester compound in Example 7
In the above, instead of the fluorinated alkyl chain used in Example 7,
And the chemical formula HOOC (CF_Two)₁₈Represented by COOH
Fluorinated alkyl compounds having carboxyl groups at both ends
Was used in the same manner as in Example 7 except that the same amount of
A fluorinated alkyl ester compound represented by the formula was obtained.           HOOCC₁₇H ₃₂ OOC (CF_Two)₁₈COOC₁₇H ₃₂ COOH Then, the same procedure as in Example 7 was carried out.
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 7
0.2% by weight of the fluorinated alkyl ester compound
Example 7 except that it was used instead of the hydrofuran solution.
A video tape was produced in the same manner. Embodiment 9 Example1Of Fluorinated Alkyl Ester Compounds in Water
In the embodiment1Used inn-heptanoic acidInstead of
Except that the same amount of 6-amino-n-hexanoic acid was used.
Is an example1In the same manner as
Thus, an alkylated alkyl ester compound was obtained.     H_TwoNC_FiveH_TenCOOCH_Two(CF_Two)₈CH_TwoOOCC_FiveH_TenNH_Two Next, the embodiment1Chemistry as above
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution was obtained.1Used in
0.2% by weight of the fluorinated alkyl ester compound used
Example 1 except that it was used instead of the trahydrofuran solution
1A video tape was produced in the same manner as described above. Embodiment 10 Synthesis of fluorinated alkyl ester compound in Example 9
In place of the alkyl fluoride chain used in Example 9,
And the chemical formula HOCH_Two(CF_Two)₁₈CH_TwoTable by OH
Fluorinated alkyl compounds having hydroxyl groups at both ends
Except for using the same amount, the following chemical
A fluorinated alkyl ester compound represented by the formula was obtained.       H_TwoNC_FiveH_TenCOOCH_Two(CF_Two)₁₈CH_TwoOOCC_FiveH_TenNH_Two Next, the same procedure as in Example 9
0.2 weight of the fluorinated alkyl ester compound represented by the formula
% Tetrahydrofuran solution, which is used in Example 9
0.2% by weight of the fluorinated alkyl ester compound
Example 9 was repeated except that the hydrofuran solution was used instead.
A video tape was produced in the same manner. Comparative Example 1 Deposition of fluorinated alkyl ester compound in Example 1
In the treatment, the alkyl fluoride used in Example 1 was used.
Instead of a 0.2% by weight solution of the tellurium compound in tetrahydrofuran
And perfluoropolyether (manufactured by Montedison Co .;
Using a 0.2% by weight Freon solution of Fomblin ZDOL)
Other than that described above, the ferromagnetic metal thin film layer was formed in the same manner as in Example 1.
A videotape was prepared. The video tapes obtained in each of the examples and comparative examples were used.
The steels were tested for still durability. Still durability
The test was conducted under the conditions of 20 ° C. and 50% RH under the condition of 8 mm VTR.
(Sony Corporation; EV-S900)
Measuring the still time until 6dB lower than the period
went. Table 1 below shows the results. [0047] [0048] As is clear from Table 1 above,
The videotapes obtained in the light (Examples 1 to 10)
These are still still compared to the conventional video tape (Comparative Example 1).
The time is long, and the
Air recording media have good still durability and excellent reliability.
You can see that

Continuation of the front page (51) Int.Cl. ⁷ identification code FI C10N 40:18 C10N 40:18 (56) References JP-A-2-210615 (JP, A) JP-A-2-163194 (JP, A) JP-A-3-241523 (JP, A) JP-A-5-274659 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/71 C07C 69/63 C07C 69/67 C10M 107/38

Claims (1)

(57) [Claim 1] A ferromagnetic metal thin film layer is provided on one or both surfaces of a non-magnetic support, and the surface of the ferromagnetic metal thin film layer is
General formula R ₁ —COO—R ₂ — (CF ₂ ) n—R ₃ —OOC—R ₄ or R ₁ —OOC—R ₂ — (CF ₂ ) n—R ₃ —COO—R ₄ [where R ₁ And R ₄ are a hydrocarbon group having 3 to 18 carbon atoms or R ₅ A, R ₅ is a hydrocarbon group having 2 to 17 carbon atoms, and A is a —COOM group (where M is a hydrogen atom or
A polar functional group selected from a potassium metal atom), an amino group or a butoxy group , R ₂ and R ₃ are a hydrocarbon group having 0 to 8 carbon atoms , and n is an integer of 2 to 40. Wherein the fluorinated alkyl ester compound represented by the formula (1) is present as a lubricant component: