JP2003303412A - Magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording medium using a substrate wherein adhesive force between an undercoating film and the substrate is enhanced and blocking of the undercoating film and a back surface is prevented. <P>SOLUTION: In the magnetic recording medium having the undercoating film on at least one surface of the substrate and a magnetic film consisting of a ferromagnetic metal thin film on the undercoating film, the undercoating film consists of a silicone resin having an acryloxy group or a methacryloxy group. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a magnetic recording medium used as a magnetic film. [0002] 2. Description of the Related Art Magnetic tape, floppy (registered trademark) data
Magnetic recording media such as discs and hard disks are common
In addition, a process for forming a magnetic film, a protective film, etc. on a non-magnetic support.
It is manufactured by the process. Such magnetic recording media
In the vacuum deposition method such as sputtering or vapor deposition
A magnetic recording medium using the manufactured ferromagnetic metal thin film as a magnetic film is provided.
It has been put into practical use. For sputtering and vapor deposition as described above
Therefore, a magnetic recording medium on which a magnetic film is formed has a high magnetic energy.
Can be easily obtained, and the surface of the non-magnetic support is flattened.
Smooth magnetic film surface is easily achieved by smoothing
High electromagnetic conversion characteristics with low spacing loss
Suitable for high-density recording materials.
The In particular, sputtering is more magnetic energy than vapor deposition.
Can increase the height of the hard disk
It is used for media that require high recording density. In recent magnetic recording media, high recording density is achieved.
There is a strong demand for increasing the degree of electromagnetic conversion.
It has become necessary. For this reason, magnetic tape and floppy
Polyethylene as a non-magnetic support like pea disc
Terephthalate film and polyethylene naphthalate
Smell using a flexible polymer film such as film
In order to improve recording density, sputtering and vapor deposition
It is desirable to form a magnetic film made of a ferromagnetic metal thin film
That's right. However, such polymer films are heat resistant.
Since it is inferior in properties, it is not suitable for film formation by sputtering or
When a film is deposited at a higher deposition rate by the deposition method,
Lum or its surface is heated to deform the non-magnetic support
(Heat loss) and surface due to oligomer precipitation
Deterioration occurs, smooth surface properties of non-magnetic support,
Problems such as difficulty in obtaining smooth surface properties of magnetic films
There is. In order to solve this problem, the following technique is used.
Skills have been proposed. One is a non-magnetic support
This method uses a heat-resistant resin as the material for the child film.
The The heat-resistant resin used is a polyimide film.
However, polyimide films are generally expensive.
is there. In addition, the polyimide film is very smooth and has good surface properties.
Film production and use is technically difficult, and this method is currently not available.
Not practical. In addition, a magnetic film is formed by coating, for example.
Relatively cheaply used in conventional magnetic recording media
Forming a base coat on a high-value polymer film,
A method for improving heat resistance has been proposed. For example, JP-A-6-349042 discloses a ratio.
Trees containing fine particles on a relatively rough polymer film
Film with appropriate surface properties by providing an oil film
A method of making is disclosed. But used here
Sputtering when using general resin binders
When a magnetic film is produced by the method, the surface is damaged due to thermal damage.
Sexual deterioration is severe. JP-A-7-225934 discloses poly.
Polyethylene naphthalate on ethylene terephthalate
A method to prevent oligomer precipitation due to heat has been developed.
It is shown. But use polyethylene naphthalate
Even up to 200 ° C, the typical temperature for sputtering
Inferior surface properties due to oligomer precipitation when the film is heated
Cause JP-A-6-208717 further discloses
Polyamide resin and polyimide resin with high heat resistance
A method of coating on a film is disclosed. like this
Using a new material fills the heat resistance to withstand the sputtering method
It is possible to grant to But polyamide trees
Fat and polyimide resin have low solubility in general-purpose solvents,
It is necessary to use a difficult solvent. In addition, the resin
Even if it is soluble in the solvent for use, the viscosity of the solution is high.
It is difficult to improve the surface properties because a thick and uniform film cannot be obtained.
It is. Furthermore, in such a method, the solvent is sufficiently dried.
It is difficult to do so, and the residual amount of solvent in the coating film increases.
Therefore, when winding the film, the back surface of the coating film and film
It is easy to cause blocking that adheres.
Residual solvent that volatilizes when the magnetic film is formed in the vacuum chamber.
There is a possibility of contamination. Further, as a highly heat-resistant film, an inorganic material is used.
It is effective to form a film, for example, silane compound
Silica film or metal alkoxide obtained by hydrolysis of products
It is possible to form a metal oxide film obtained from
The However, such inorganic coatings have nonmagnetic support.
It cannot keep up with the heat change of the holder, and the surface of the film is cracked.
If a crack occurs in the magnetic film deposited on it
There is a problem. Assume that these problems have been solved to some extent.
Described in Japanese Patent Laid-Open No. 8-329443 by the present applicant.
The bottom is mainly made of Si-O or Si-O-N
There is a magnetic recording medium having a coating layer. This magnetic recording medium
Has a smooth surface property and is also a spa with heating of the support.
Even when a magnetic film is produced by the
There is no possibility of causing racking and blocking.
It has a small undercoat. However, this
In the preparation of the undercoat, repellency occurs when the raw material is applied.
It is difficult to make the lower coating film uniform.
It was difficult. Also, this undercoat should be overcoated
It is impossible to increase the thickness of the film.
It was. Therefore, in order to address the above-mentioned problems, the present applicant.
Is a silane compound containing an organic residue having an aromatic hydrocarbon group.
Heat-resistant undercoating film mainly composed of polymer of pulling agent
Proposed. However, no corona treatment has been applied
Adhesion between the interface with the undercoat in aramid supports, etc.
There were cases where power was not enough. And improve adhesion
When you add a compound containing gyoyo and sulfonic acid,
The back surface is crushed, improving the adhesion and achieving both
There was a problem that I could not. [0013] SUMMARY OF THE INVENTION The present invention provides an undercoat and support.
The adhesion between the bodies improves and the undercoat and back side
Providing a magnetic recording medium using a support that prevents ripening
The task is to do. [0014] SUMMARY OF THE INVENTION The present invention reduces the number of supports.
From at least one surface with an undercoat and a ferromagnetic metal film on top
In the magnetic recording medium having the magnetic film, the undercoat is
Including compounds having aromatic groups and / or epoxy groups
Compound represented by the general formula (1A), and acryloxy
General formulas including compounds having a group or a methacryloxy group
From the reaction product of the mixture containing the compound represented by (1B)
And the compound represented by the general formula (1B) is represented by the general formula
0.1 parts with respect to 100 parts by mass of the compound represented by (1A)
A magnetic recording medium characterized by using ˜60 parts by mass. General formula (1A) (R¹)_a-Si-X_b (Wherein, a + b = 4, a = 0-3 (where b is 2 or more)
At least) and R¹Is epoxy
Represents an organic group having 1 to 40 carbon atoms which may have a group, and X represents
A hydrolyzable group is shown. ) General formula (1B) (R²)_c-Si-X_d (Where c + d = 4, c = 1-3, R²Is Acry
Number of carbon atoms that may have a roxy group or a methacryloxy group
1-40 organic groups are shown, X shows a hydrolysable group. ) Preferred embodiments of the present invention are as follows. (1) The ferromagnetic metal thin film is formed by sputtering.
It must have been (2) The magnetic recording medium is disk-shaped. (3) The compound represented by the general formula (1A) on the support
And a coating solution containing the compound represented by the general formula (1B)
After coating, before forming the undercoat by heating
To obtain a magnetic recording medium. (4) Adding a curing agent to the coating solution. (5) A curing agent comprising a metal chelate compound in the coating solution.
To add. [0015] DETAILED DESCRIPTION OF THE INVENTION According to the present invention, an undercoating film is formed on a support.
Formed by the compound represented by the general formula (1A)
Product (hereinafter also referred to as compound (1A)) and the above general formula
Compound represented by (1B) (hereinafter referred to as Compound (1B))
The reaction product of the mixture containing acryloxy groups or
Since it has a methacryloxy group, adhesion to the support is improved.
As well as ensuring blocking resistance, stable good
A favorable magnetic recording medium can be obtained. The undercoat is
It consists of siloxane bonds but contains at least organic groups
Compared with conventional polyester resin, etc., heat resistance,
Excellent blocking resistance. This polymer film is also
To the sol-gel method using traethoxysilane as a starting material
Therefore, it is superior in crack resistance compared to the silica film produced.
It is. In addition, the organic group of the lower coating film imparts flexibility to the coating film.
To improve crack resistance and provide an appropriate surface error.
Because energy can be achieved,
This effect can be reduced by the adhering matter on the support.
This is particularly noticeable when there are defects. Furthermore, the present invention
Even when applying further on the undercoat of
Can be applied without repelling.
The film thickness can be increased. Furthermore, in the present invention, a silicone resin monomer is used.
-Using the solution as a coating solution to form an undercoat
The viscosity of the coating solution is low and the prepared undercoat is smooth.
It is particularly excellent in nanometer and sub-nanometer
Smooth on scale. Therefore, for future high recording density magnetism
It is very suitable as a substrate for recording media. Furthermore, even if the medium is placed on top, the undercoat component
That there is no blocking (sticking) due to migration
There are signs. The compound (1A) will be described. Where
a + b = 4, a = 0-3 (provided that b is 2 or more)
At least, and preferably a = 1
The R¹Has 1 to 40 carbon atoms which may have an epoxy group
X represents an organic group, and X represents a hydrolyzable group. The organic group includes an aliphatic group and an aromatic group.
Can be mentioned. Aliphatic groups include alkyl groups and alkeni
Group, alkynyl group, aralkyl group, etc.
An alkyl group is preferred and one having 1 to 40 carbon atoms is preferred.
And those having 1 to 35 carbon atoms are more preferred. Alkyl group
Can be cyclic, linear, branched or a combination thereof
Good. As the aromatic group, a phenyl group is preferable. Organic
Among the groups, in particular methyl or phenyl groups, epoxies
Si group and glycidyl group are preferred. R¹And / or X
In the case of numbers, they may be the same or different. Compound (1A) is an aromatic group and / or
Including compounds having a poxy group. Accordingly, compound (1
A) includes at least an aromatic group as an organic group
Compound containing or organic hydrogen atoms are placed in epoxy groups
The converted compound must be included. Next, X will be described. X is hydrolyzable
Indicates a group. Hydrolyzable groups react with -OH groups or water
Means a group that can be converted to an —OH group, for example, halogen
Atom, alkoxy group, acetoxy group, amino group, isop
Examples include lopenoxy groups, with alkoxy groups being preferred.
In particular, a methoxy group or an ethoxy group is preferable. Next, the compound (1B) will be described. formula
C + d = 4, c = 1-3, R²Is acryloki
1 to C carbon atoms which may have a silyl group or a methacryloxy group
40 represents an organic group, and X represents a hydrolyzable group. However
And at least one of the organic groups is an acryloxy group or
Must have a methacryloxy group. In the present invention, acryloxy group or meso
There are few organic groups having 1 to 40 carbon atoms having a tacryloxy group.
At least interaction with the support such as electrostatic interaction and hydrogen bonding
This action allows adhesion between the support and the undercoat
Power is improved. R²Specific examples of are the same as in compound (1A)
An acryloxy group or a methacryloxy group
The converted one is preferred. X is as defined above. R¹
And / or when there are a plurality of X, they are the same or different
Also good. Specific examples of the compound (1B) include γ-mes
Tacryloxypropyltrimethoxysilane, γ-metac
Liloxypropyldimethoxymethylsilane, γ-metac
Liloxypropyltriethoxysilane, γ-methacrylo
Examples thereof include xylpropyldiethoxymethylsilane. Compound ratio of compound (1A) and compound (1B)
Is 0.1 to 6 with respect to 100 parts by mass of the compound (1A).
It is preferable to use 0 parts by mass, and 1 to 55 parts by mass is used.
More preferably. In addition, the compound (1A) is excellent.
Compound having aromatic group and / or compound having epoxy group
It is preferable that a compound is included. Has an aromatic hydrocarbon group
Examples of the compound include those represented by the following general formula (1a).
A compound (1a) is mentioned. [0027] [Chemical 1] However, R^Three, R^FourIs monovalent organic such as methyl group
Group, A is a divalent organic group such as an alkylene group or none (direct
Conclusion), X is as defined above, and x + y + z = 4. In the compound (1a), A is preferably none.
(Directly connected) or a methylene group. X is reactive
Preferred is an alkoxy group, which facilitates the polymerization reaction
Therefore, especially alkoxy groups having 4 or less carbon atoms such as methoxy groups
Is preferred. x is preferably 1 or 2, but polymerization
In order to facilitate the reaction, it is particularly preferable that it is 1.
y is preferably 0 or 1, but facilitates the polymerization reaction.
Therefore, it is particularly preferably 0. Therefore z is especially 3
It is preferable that As such a compound (1a), [0031] [Chemical 2] And the like. Examples of the compound having an epoxy group are as follows:
Examples thereof include the compound (1b) represented by the general formula (1b). [0034] [Chemical Formula 3] However, A¹Is a divalent organic such as an alkylene group
Group, R^FiveIs a monovalent organic group such as hydrogen or an alkyl group,
R⁶Is a monovalent organic group such as an alkyl group, X is
Soluble group, L + M + N = 4. In the compound (1b), R^FiveIs preferably
It is a hydrogen atom. R⁶Is preferably a methyl group, ethyl
A monovalent organic group such as a group. X is reactivity or corrosion on the magnetic film
In consideration of food habits, an alkoxy group is preferable, and polymerization is performed.
In order to facilitate the reaction, especially methoxy groups such as 4 or more carbon atoms
The lower alkoxy groups are preferred. A¹Is preferably ate
An alkylene group having 1 to 5 carbon atoms and M is preferred
1 or 2 to facilitate the polymerization reaction.
Therefore, it is particularly preferable that it is 1. L is preferably 0
Or 1 but is particularly preferred because it facilitates the polymerization reaction.
Or 0. Therefore, N is particularly preferred to be 3.
Yes. Such compounds include: [0038] [Formula 4] And the like. These compounds are disclosed in JP
Described in Sho 51-11871 and JP-A 63-23224
It is listed. Hydrolysis of the above compounds (1A) and (1B)
The dissolvable group is coated and dried by the method described below.
Hydrolysis and polymerization produce siloxane bonds. on the other hand,
The epoxy group undergoes ring-opening polymerization with an acid catalyst or heat. This
Add acid such as hydrochloric acid as needed for water splitting and polymerization rate
It can be adjusted by doing. Formed in this way
The acryloxy derived from the compound (1B)
Si group or methacryloxy group is bonded. Curing to initiate polymerization from a lower temperature
A combination of agents is preferred, for example, metal chelate compounds, organic
Various compounds such as acids and their salts, perchlorates are known
However, especially as a curing agent (curing catalyst), the low temperature of curing
Metal chelate compounds for reasons of corrosion and corrosiveness to magnetic films
preferable. For example, 3-glycidoxypropyl trimethoxy
Curing aluminum acetylacetonate on silane etc.
When added as a catalyst, heat at around 100 ° C for a short time
Polyethylene terephthalate, etc.
It can be cured even on a substrate with low heat resistance. So gravure
Winding without blocking using the continuous coating method
Can be taken. Such curing agents include aluminum
Nium anethyl acetonate, Zirconium anethyl acetonate
Β- such as cetonate, titanium acetylacetonate
Diketones and metal chelate compounds are particularly effective. Also, heat resistance, cost reduction, polymerization rate adjustment
For example, a silane containing a hydrocarbon group such as a methyl group
Mix the coupling agent (contained in compound (1A))
May be used. Silane coupling containing hydrocarbons
When used together, the heat resistance of the lower coating can be improved.
The Specifically, this hydrocarbon group-containing silane coupling
The adhesive has the following structure. R⁷-Si (OR⁸)_Three However, R⁷, R⁸Is a hydrocarbon group, R⁷The carbon number of
It is effective in improving the heat resistance of the throat coating. The undercoat is applied to the support with compound (1A) and
The shape is obtained by applying a coating solution containing (1B) to the support.
Can be made. Preferably, the compound on the support
(1A) and (1B), a curing agent, hydrochloric acid such as methanol
Wire bar using solution dissolved in organic solvent as coating liquid
Method, gravure method, spray method, dip coating method,
After coating on a support by a method such as coating,
A drying method can be used. After this,
If necessary, the lower coating is baked to accelerate curing,
Improve solvent resistance and adhesion. The coating solvent used at this time is addition of hydrochloric acid.
Determined by the amount and structure of the silane coupling agent
Ethanol, methanol, isopropyl alcohol
And cyclohexanone can be used. Drying is performed to volatilize the solvent.
It is possible to cure at this point at the same time.
it can. As a drying method, hot air drying is generally used.
Drying, infrared drying, etc. can be used. Drying temperature at this time
Is preferably about 60 ° C to 150 ° C. After the coating is dried, the curing is further accelerated.
As firing methods, hot air heating, infrared heating, hot roller heating
Heat can be used. The heating temperature at this time is a coating film
Depends on the thickness of the film, the method of film formation and the film formation temperature
However, in the case of around 1 μm, 100 ° C. to 250 ° C. is preferable.
Or in the range of 120 ° C to 200 ° C. Temperature is higher than this
Is too low, the progress of the polymerization reaction is insufficient.
Too much can cause deformation of the support or decrease in productivity.
Leads to. In addition to polymerization by heating, ultraviolet irradiation,
Polymerization by electron beam irradiation or the like is also possible. In addition, the base coating film of the present invention contains components other than those described above.
It may be contained. Such additives include surface
Heat-resistant fine particles (filler)
-), Metal for adjusting heat resistance and coating hardness
Alkoxide, cup to improve adhesion to support
Examples include ring agents and rust preventives to prevent oxidation of magnetic films.
It is. Heat-resistant fine particles for providing irregularities on the surface;
Silica, alumina, titania, zirconia, etc.
Examples include inorganic oxides, calcium carbonate, carbon, and polymers
It is done. The shape is preferably monodispersed and spherical.
Good. The particle size is selected according to the film thickness of the undercoat
5 to 1000 nm, preferably 10 to 100 nm
The The coating solution for the undercoat is mainly alcohol, cyclohex
Because it is a solution of SANON, MEK, toluene, etc., it is heat resistant
Fine particles are dispersed in one or more of these solvents.
Silazozo dispersed in an organosilica sol or acidic aqueous solution
And the like are particularly suitable. To adjust the heat resistance and the hardness of the coating film
Examples of metal alkoxides include tetraethoxysilane and te
Such as trapropoxyzirconium.
Heat resistance and hardness can be improved by addition. The support used in the present invention is a flexible substrate.
In the case of a shibble medium, the polyethylene is 3 to 100 μm thick.
Terephthalate, polyethylene naphthalate, poly
Films such as imide, polyamide, polyamideimide, etc.
Can be used. Also contains a filler inside the film
And what formed the unevenness | corrugation in the film surface may be used. one
On the other hand, in the case of rigid media, glass substrate, aluminum substrate
A carbon substrate can be used. In addition, the undercoat film of the present invention improves adhesion to the support.
Excellent, but silane coupling when adhesion is insufficient
Surface treatment of the support with additives such as agents and oxygen plasma
Ma, argon plasma, ultraviolet irradiation, electron beam irradiation, flame
It is preferable to perform a process such as the above. The magnetic film in the magnetic recording medium of the present invention
Ferromagnetic metal thin films are conventionally known as vacuum deposition methods and spatters.
It can be formed by the data method. When the magnetic film is formed by sputtering, the composition
As a conventionally known metal mainly composed of cobalt or
Is an alloy, specifically, Co-Cr, Co-Ni.
-Cr, Co-Cr-Ta, Co-Cr-Pt, Co-
Cr-Ta-Pt, Co-Cr-Pt-Si, Co-C
r-Pt-B or the like can be used. Especially improved electromagnetic conversion characteristics
Co-Cr-Ta and Co-Cr-Pt are preferred
That's right. The thickness of the magnetic film is preferably 10 to 300 nm.
That's right. In this case, the magnetic properties of the magnetic film can be improved.
It is preferable to provide an undercoat film, and the composition of this undercoat film
Examples include conventionally known metals or alloys.
Specifically, Cr, V, Ti, Ta, W, Si, etc.
Can use these alloys, especially Cr, Cr-Ti,
Cr-V and Cr-Si are particularly preferable. The thickness of this base film
The thickness is 5 nm to 500 nm, preferably 10 nm.
nm to 200 nm. When a magnetic film is formed by sputtering.
The film can be formed with the substrate or film heated.
Preferably, the temperature at that time is around 150 to 200 ° C.
The When the magnetic film is formed by vacuum deposition, the composition
As a conventionally known metal mainly composed of cobalt or
Is an alloy, specifically, Co, Co-Ni, Co
-Fe, etc. are deposited in an oxygen atmosphere, and the film contains oxygen.
Can be used. Especially to improve electromagnetic conversion characteristics
More than 90% of the metal atoms constituting the magnetic layer, more preferred
Or 95% or more of Co—O, which is cobalt, or Co
Co-Fe containing -O is preferred. Magnetic layer thickness
Is preferably 100 to 300 nm, and further desired
It is preferably 120 to 200 nm. In addition, the ferromagnetic metal thin film has improved electromagnetic conversion characteristics.
In order to improve the structure, a multi-layer structure is used.
You may have. In the magnetic recording medium of the present invention, ferromagnetic gold
A protective film may be provided on the metal thin film.
Can further improve running durability and corrosion resistance.
Yes. As the protective film, silica, alumina, titani
Acids such as a, zirconia, cobalt oxide and nickel oxide
Nitride of titanium, titanium nitride, silicon nitride, boron nitride, etc.
Products, carbides such as silicon carbide, chromium carbide, boron carbide,
Protection made of carbon, such as graphite and amorphous carbon
A membrane is mentioned. The carbon protective film is formed by plasma CVD or sputtering.
Amorphous, graphite produced by the sputtering method, etc.
A diamond structure, or a mixture of these
Carbon film, particularly preferably diamond
It is a hard carbon film called dry carbon. This
Hard carbon film has a Vickers hardness of 1000 kg / mm ²
(9.8 GPa) or more, preferably 2000 kg / mm
²It is a hard carbon film of (19.6 GPa) or more. Ma
The crystal structure is amorphous and non-conductive.
Electricity. Then, the structure of the diamond-like carbon film is
When measured by Mann optical spectroscopy, 1520-
1560cm^-1Confirmed by detecting a peak in
can do. Carbon film structure is diamond-like structure
When detected, the peak detected by Raman spectroscopy is detected.
And the hardness of the carbon film is low.
I will give you. This hard carbon protective film is made of methane, ethane,
Alkanes such as lopan and butane, ethylene,
Alkenes such as pyrene or alkynes such as acetylene
Plasma CV using carbon-containing compounds as raw materials
D, or carbon in a hydrogen or hydrocarbon atmosphere
It can be formed by a sputtering method or the like. When the hard carbon protective film is thick, electromagnetic conversion characteristics
Deterioration of adhesion and deterioration of adhesion to the magnetic layer occur, and the film thickness
If it is thin, the wear resistance is insufficient, so the film thickness is 2.5 to 20n.
m is preferable, and 5 to 10 nm is particularly preferable. In addition, the moisture applied on the hard carbon protective film.
Hard carbon protective film for the purpose of further improving adhesion with lubricant
Surface treatment with oxidizing or inert gas
Also good. In the magnetic recording medium of the present invention, running durability
In order to improve the properties and corrosion resistance,
It is preferable to apply a lubricant or a rust preventive agent on the protective film. As the lubricant, known hydrocarbon lubricants,
Fluorine lubricants, extreme pressure additives, etc. can be used. As the hydrocarbon lubricant, stearic acid,
Carboxylic acids such as oleic acid, butyl stearate, etc.
Esters, sulfonic acids such as octadecyl sulfonic acid
, Phosphate esters such as monooctadecyl phosphate,
Alcohol such as tealyl alcohol and oleyl alcohol
, Carboxylic acid amides such as stearamide,
Examples include amines such as tealylamine. Fluorine-based lubricants include the above hydrocarbon-based lubricants.
Part or all of the alkyl group of the lubricant is fluoroalkyl
Lubricant substituted with a group or perfluoropolyether group
Agents. As perfluoropolyether group
Perfluoromethylene oxide polymer, perfluoroethylene
Tylene oxide polymer, perfluoro-n-propylene
Oxide polymer (CF₂CF₂CF₂O)_n, Perfluoro
Isopropylene oxide polymer (CF (CF_ThreeCF
₂O)_nOr these copolymers. Examples of extreme pressure additives include trilauryl phosphate
Phosphorous esters, phosphorous such as trilauryl phosphite
Acid esters, thios such as trilauryl trithiophosphite
Phosphites, thiophosphates, disulfide disulfides
And sulfur-based extreme pressure agents such as The above lubricants may be used alone or in combination.
used. Apply these lubricants on the magnetic film or protective film.
As a method of applying to a solvent, a lubricant is dissolved in an organic solvent, and
Ear bar method, gravure method, spin coating method, dip
Apply by coating or attach by vacuum evaporation
Just do it. The coating amount of the lubricant is 1 to 30 mg / m.
²2-20 mg / m²Is particularly preferred. As a rust inhibitor usable in the present invention, benzoate is used.
Triazole, benzimidazole, purine, pyrimidi
Nitrogen-containing heterocycles such as
Derivatives introduced with side chains, benzothiazole, 2-mer
Kapton benzothiazole, tetrazaindene ring compound
And sulfur containing heterocycles such as thiouracil compounds
And derivatives thereof. [0073] EXAMPLES Specific examples of the present invention will be described below.
The present invention is not limited to this. Thickness 20μm
Phenyltriethoxysilane (trust)
KBE-103 manufactured by Koshi Chemical Industry Co., Ltd. and γ-glycidoxy
Propyltrimethoxysilane (Shin-Etsu Chemical KBM
-403) at a mass ratio of 1: 1, and γ-methacryloxy
Propyltrimethoxysilane (Shin-Etsu Chemical KBM
-503) in an amount of 25% by mass (relative to phenyltriethoxysila)
And γ-glycidoxypropyltrimethoxysilane
(Mass ratio), and after dissolving hydrochloric acid in ethanol, cure
Add aluminum acetylacetonate as an agent
A coating solution was prepared. Apply this solution by gravure coating
And dried at 100 ° C. to produce a 1 μm-thick undercoat
did. Next, using a 10 μm thick adhesive sheet,
Laminate the film on the outside, and the total thickness is 50 μm.
After forming into a film, it is heated at 170 ° C. for 2 hours.
The adhesive was cured and the solvent was removed. This film
Installed in a putter device, DC magneto at a substrate temperature of 150 ° C
A Cr-Ti underlayer is formed to 60 nm by using a ron sputtering method.
And then a Co-Pt-Cr magnetic film is formed to a thickness of 30 nm.
It was. Next, this film is installed in a plasma CVD apparatus,
Hardened by plasma CVD using ethylene as a raw material on the magnetic film.
A carbonaceous protective film was formed to a thickness of 20 nm. Next on this protective film
Perfluoropolyether lubricant (manufactured by Augmont)
FOMBLIN Z-DOL) is a fluorinated solvent (Sumitomo 3)
The solution dissolved in MFE HFE-7200)
A lubricating film having a thickness of 2 nm was prepared by applying the coating method. this
Undercoat, undercoat, magnetic film, protective film, lubricating film are films
Films were formed on both sides. And this sample is 3.7 inches
Punched into the shape of a magnetic disk
Made. Example 2 In Example 1, γ-methacryloxypropyltrimeth
5 grades of xylan (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.)
% By weight (vs. phenyltriethoxysilane and γ-glycidoxy
(Total mass ratio of cypropyltrimethoxysilane) added
A sample was prepared in the same manner as in Example 1 except for the above. Example 3 In Example 1, γ-methacryloxypropyltrimeth
55 xysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.)
Mass% (vs phenyltriethoxysilane and γ-glycid
Total mass ratio of xylpropyltrimethoxysilane)
A sample was prepared in the same manner as in Example 1 except that. Comparative Example 1 In Example 1, γ-methacryloxypropyltrimeth
Adds xysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.)
The sample was prepared in the same manner as in Example 1 except that the lower coating film was formed.
Produced. Comparative Example 2 In Example 1, γ-methacryloxypropyltrimeth
65 xysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.)
Mass% (vs phenyltriethoxysilane and γ-glycid
Total mass ratio of xylpropyltrimethoxysilane)
A sample was prepared in the same manner as in Example 1 except that. The prepared sample was evaluated from the following viewpoints.
It was. The flexible disk is made of a fluorinated solvent (Sumi
Tomo 3M HFE-7200) soaked in lubricant
After washing, a sample piece was cut into a width of 2 cm. On the sample
Mending tape (MD-18 manufactured by Nichiban Co., Ltd.)
When the substrate is applied and peeled off by hand, the support and undercoat interface
If there is any peeling, there is peeling.
If the sample was peeled off and the sample was not changed,
It was. Mending tape (Michi manufactured by Nichiban Co., Ltd.)
D-18) is fixed so that the adhesive surface is the upper surface, and the sample piece
1.0 in the direction perpendicular to the longitudinal direction of the mending tape
cm was pasted. Stick a spring scale to the non-fixed end of the specimen.
Fix it with adhesive tape, pull it in the direction of the arrow in Fig. 1, and peel it off.
The load at that time was evaluated as the adhesion. Also bonded
Check if there is any tension when unwinding the later film
It was. ○ that can be rolled out without causing surface roughness
What has been observed to be whitening due to surface roughness
×, whitening does not occur, but when observed with an optical microscope,
A case where a rickety mark was observed was rated as Δ. The above evaluation results
Table 1 shows. [0080] [Table 1] [0081] According to the present invention, as a base coating on the support,
The formed silicone resin is, for example, an aromatic hydrocarbon
A silane coupling agent having an epoxy group or an epoxy group
Silane coupling agents and acryloxy groups or methacrylates
Compound containing silane coupling agent having riloxy group
A mixture of siloxane bonds, and
Because it has a bond due to ring opening of the poxy group,
Heat resistance and blocking resistance compared to re-ester resin, etc.
It has excellent grip properties. This polymerized film is made of tetraethoxy
Prepared by the sol-gel method using silane and other starting materials.
Excellent crack resistance compared to silica films. Further
In the present invention, the lower coating film has an acryloxy group or methacrylo group.
Adhesion with the support is improved due to having a xy group.
In addition, the peeling between the lower coating and the back surface is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a method for measuring the adhesion between a support and an undercoat film interface;

─────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme code (reference) C09D 183/04 C09D 183/04 183/07 183/07 // C08L 101: 00 C08L 101: 00

Claims (1)

1. An undercoat film on at least one surface of a support,
In the magnetic recording medium having a magnetic film comprising a ferromagnetic metal thin film thereon, the lower coating film comprises a compound represented by the following general formula (1A) containing a compound having an aromatic group and / or an epoxy group, and acryloxy A compound represented by the general formula (1B) including a compound having a group or a methacryloxy group, and represented by the general formula (1A) A magnetic recording medium comprising 0.1 to 60 parts by mass with respect to 100 parts by mass of the compound. Formula (1A) (R ¹⁾ in _a -Si-X _b (wherein, a + b = 4, a = 0~3 ( although, b is at least included) those is 2 or more, R ¹ represents an epoxy group And _C represents a hydrolyzable group.) General Formula (1B) (R ² ) _c —Si—X _d (where c + d = 4, c = 1 to 3, R ² represents an organic group having 1 to 40 carbon atoms which may have an acryloxy group or a methacryloxy group, and X represents a hydrolyzable group.)