JP2523272B2 - Magnetic recording media - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Technical Field The present invention relates to a magnetic recording medium. For more information,
The present invention relates to a magnetic recording medium having a predetermined plasma polymerized film for improving durability, scratch resistance and the like.

In the prior art and problems non-magnetic substrate, a magnetic recording forming a magnetic layer mainly composed of the γ-Fe ₂ O _3, Co oxide-based magnetic powder such deposited γ-Fe ₂ O ₃ bonding agent It's been a long time since the medium appeared.

Recently, for the purpose of further improving the recording density,
Fe, Co, Ni, Fe-Co, Co-Ni, Fe-Co-Ni, Fe-Co-
B, Fe-Co-Cr-B, Mn-Bi, Mn-Al, Fe-Co-V and other ferromagnetic powders and magnetic recording media made of a binder and the like have been put to practical use.

Furthermore, as a magnetic layer capable of thinning the magnetic layer for higher density recording, a vapor phase thin film such as a metal vapor deposition thin film or a sputtered thin film, or a liquid phase plating thin film such as an electroless plating thin film is used as the magnetic layer. Magnetic recording media are put to practical use,
It is in the limelight.

In these continuous thin film type magnetic recording media, particularly in the applications of magnetic tapes and magnetic disks, the friction coefficient is small, smooth and stable running property is exhibited, and abrasion resistance is excellent, and stable running is performed for a long time. It is strongly demanded that the materials be stable, reproducible at all times, and durable and scratch resistant.

Conventionally, various pretreatments have been performed on a substrate for the purpose of improving durability and scratch resistance.

The pretreatment includes chemical treatment, coating treatment, corona discharge treatment and the like.

However, among these, the corona treatment does not have a sufficient effect. Further, in the chemical treatment and the coating treatment, there is a problem that the treatment process is complicated and the cost required for the treatment is high.

Under such circumstances, the present researchers have proposed plasma processing for substrates (Japanese Patent Application No. 59-107178, etc.).

Since the plasma treatment method is composed of only one step and is a dry process, it has advantages that drying and waste liquid treatment are not required and that raw materials such as a binder are not consumed. further,
Since the plasma treatment method enables continuous production at a high speed, it can be easily incorporated in the magnetic recording medium manufacturing process and does not impair its productivity.

Such plasma treatment methods generally include air, oxygen,
Nitrogen, hydrogen, helium, argon, etc. are used as the processing gas.

Then, according to these plasma treatments, the adhesive force between the substrate and the magnetic layer is improved, and the durability is improved.

However, the requirements for durability and scratch resistance of the magnetic recording medium are strict, and further improvement is required.

II OBJECT OF THE INVENTION It is an object of the present invention to provide a continuous thin film type magnetic recording medium in which durability and scratch resistance are remarkably improved.

III Disclosure of the Invention Such an object is achieved by the present invention described below.

That is, the first invention is such that C, H, N, and O are formed on the substrate.
And C content is 30 ~ 90at% and atomic ratio is H / C
1/6 to 1, N / C 1/20 to 3/10, O / C 1/20 to 3/10 with a film thickness of 5 to 80Å. A magnetic recording medium having thereon a ferromagnetic metal thin film layer formed by a vapor phase or liquid phase plating method, directly or through an underlayer.

A second invention comprises C, H and O on a plasma-treated substrate, the content of C is 30 to 90 at% and the atomic ratio of H /
It has a plasma polymerized film with a film thickness of 5 to 80Å in which C is 1/6 to 1, N / C is 1/20 to 3/10, and O / C is 1/20 to 3/10. The magnetic recording medium is characterized in that it has a ferromagnetic metal thin film layer formed thereon by a vapor phase or liquid phase plating method directly or through an underlayer.

IV Specific Structure of the Invention Hereinafter, the specific structure of the present invention will be described in detail.

The plasma polymerized film of the present invention contains C, H, N, and O.

As the raw material gas, methane, ethane, propane, butane, pentane, ethylene, propylene, butene, butadiene, acetylene, methylacetylene, and other saturated or unsaturated hydrocarbons that are gaseous at room temperature are usually used because they have good operability. Although one or more kinds are used, hydrocarbons that are liquid at room temperature may be used as a raw material, if necessary.

H _2, O _2, O ₃ to 1 or more such hydrocarbons, H ₂ O, N
_The above C + H + N is prepared by using, as a raw material gas, one or more kinds of NO _x such as ₂ , NO, N ₂ O and NO ₂ , NO ₃ , NH ₃ , CO and CO ₂ are added.
Realize a + O composition.

Further, if necessary, sources such as Si, B, P and S can be added to the raw material as trace components.

The film thickness of the plasma polymerized film formed using such a raw material is 5 to 80Å.

If this film thickness exceeds 80Å, the internal stress during film formation remains in the film, the strength of the film itself decreases, and the plasma polymerized film itself is inferior in durability as a flexible medium, resulting in magnetic recording. It cannot be used practically as a medium.

 Further, if it is less than 5Å, the present invention becomes ineffective.

An ellipsometer or the like may be used to measure the film thickness.

The film thickness can be controlled by controlling the reaction time at the time of forming the plasma polymerized film, the flow rate of the raw material gas, and the like.

The plasma polymerized film forms a polymerized film by bringing the above-mentioned discharge plasma of the source gas into contact with the substrate.

When the principle of plasma polymerization is outlined, when a gas is kept at a low pressure and an electric field is applied, free electrons, which are present in a small amount in the gas, have a very large intermolecular distance as compared with atmospheric pressure, and therefore are subjected to an electric field acceleration of 5 to 10 eV. Acquire kinetic energy (electron temperature).

When the accelerated electrons collide with atoms or molecules, they break up the atomic orbitals and molecular orbitals and dissociate them into species that are unstable in normal conditions, such as electrons, ions, and neutral radicals.

The dissociated electrons are again accelerated by the electric field to dissociate another atom or molecule, and the chain action immediately turns the gas into a highly ionized state. And this is called plasma gum.

Since gas molecules have few opportunities to collide with electrons, they do not absorb much energy and are kept at a temperature close to room temperature.

Thus, the kinetic energy of electrons (electron temperature)
The system in which the thermal motion (gas temperature) of molecules is separated is called low-temperature plasma, and here we are creating a situation where additive chemical reactions such as polymerization can proceed while the chemical species remain relatively intact.
The present invention utilizes this situation to form a plasma polymerized film on a substrate. Since low temperature plasma is used, there is no thermal effect on the substrate.

An example of an apparatus for forming a plasma polymerized film on the surface of a substrate is shown in FIG. FIG. 1 shows a plasma polymerization apparatus using a variable frequency power source.

In FIG. 1, a raw material gas is supplied to a reaction vessel R from a raw material gas source 511 or 512 via mass flow controllers 521 and 22, respectively. Gas source 511 or 512
When different gases are supplied from the above, they are mixed and supplied in the mixer 53.

The raw material gas may have a flow rate range of 1 to 250 ml / min.

A substrate supporting device is installed in the reaction vessel R, and here, a feeding roll 561 and a winding roll 562 are shown for the purpose of processing a substrate for a magnetic tape.

Various supporting devices can be used depending on the form of the magnetic recording medium, and for example, a stationary rotary supporting device can also be used.

Electrodes 551 and 552 that face each other with the substrate sandwiched are provided, one electrode 551 is connected to, for example, a frequency variable power source 54, and the other electrode 552 is grounded.

Further, a vacuum system for evacuating the inside of the reaction vessel R is provided in the reaction vessel R, and this is equipped with a liquid nitrogen trap 5.
7. Includes oil rotary pump 58 and vacuum controller 59.
These vacuum systems maintain the inside of the reaction vessel within a vacuum range of 0.01 to 10 Torr.

In the operation, first, the inside of the reaction vessel R is evacuated by an oil rotary pump until it becomes 10 ⁻³ Torr or less, and then the raw material gas is supplied in a mixed state into the vessel at a predetermined flow rate.

At this time, the vacuum in the reaction vessel is controlled within the range of 0.01 to 10 Torr.

When the substrate transfer speed and the source gas flow rate are stable, the power is turned on. In this way, a plasma polymerized film is formed on the moving substrate.

Note that Ar, N ₂ , He, H ₂ or the like may be used as the carrier gas.

Further, the applied current, the processing time, etc. may be set under normal conditions.

As the plasma generation source, any of microwave discharge, direct current discharge, alternating current discharge and the like can be used in addition to high frequency discharge.

The plasma-polymerized film thus formed contains C + H + N + O as described above, and the content of C is 30 to 90 at% in the plasma-polymerized film.

When the content of C is less than 30 at%, the film strength of the plasma-polymerized film is lowered and it cannot be put to practical use.

In addition, the content of H, N, and O contained in one or more kinds in addition to C is such that the atomic ratio of hydrogen and carbon (H / C ratio) is 1/6 to 1, and the atomic ratio of nitrogen and carbon (N / C ratio) is 1/20 to 3/10, and the atomic ratio of oxygen and carbon (O / C ratio) is 1/20 to 3/10. Thus, by containing H, N, and O in addition to C, scratch resistance is improved.

The content of C, H, N, O and other elements in the plasma polymerized film may be analyzed according to SIMS (secondary ion mass spectrometry) or the like. When SIMS is used, since the plasma polymerized film of the present invention has a thickness of 5 to 80 Å, C, H, N, O and other elements may be counted and calculated on the surface of the plasma polymerized film.

Alternatively, while performing ion etching with Ar etc.,
It may be calculated by measuring profiles of C, H, N, O and other elements.

For the measurement of SIMS, Surface Chemistry Basic Course Volume 3 (1984) Surface Analysis Basics and Applications (P70) “SIMS and LAM
MA ".

Such a plasma polymerized film is preferably formed on a substrate, particularly on a plasma-treated substrate.

By plasma-treating the surface of the substrate, the adhesive force between the substrate and the plasma polymerized film is improved.

The principle, method, formation conditions, etc. of the plasma treatment method for the substrate surface are basically the same as those of the plasma polymerization method described above.

However, as a general rule, the plasma treatment uses an inorganic gas as a treatment gas, while as a general rule, an organic gas (inorganic gas may be mixed depending on the case) is used to form the plasma-polymerized film by the above-mentioned plasma polymerization method. ) Is used as a source gas.

The plasma processing gas of the present invention is not particularly limited. That is, it may be any of H ₂ , Ar, He, O ₂ , N ₂ and air.

In such a case, it is preferable to use an inorganic gas containing at least one of O, N and H.

Examples of such an inorganic _{gas, N 2, H 2, NH} 3, O 2,
O ₃ , H ₂ O, NO, N ₂ O, NO ₂ and other NO _{X and the} like are appropriately selected, and these are used alone or as a mixture, or these and Ar,
A mixture of He, Ne and the like is preferable.

Further, the frequency of the plasma processing power source is not particularly limited, and may be DC, AC, microwave, or the like. Of these, 10 KHz to 200 KHz is particularly preferable.

At frequencies of 10 KHz to 200 KHz, durability and adhesive strength are extremely high.

Thus, as a more preferable embodiment, the plasma-polymerized film is formed on the plasma-treated substrate, and further on the polymerized film, directly or through the underlayer,
A ferromagnetic metal thin film layer (hereinafter, simply referred to as a magnetic thin film layer) is formed.

The composition of such a magnetic thin film layer includes iron, cobalt, nickel and other ferromagnetic metals, or Fe--Co, Fe.
-Ni, Co-Ni, Fe-Si, Fe-Rh, Co-P, Co-B, Co-
Si, Co-V, Co-Y, Co-La, Co-Ce, Co-Pr, Co-S
m, Co-Pt, Co-Mn, Fe-Co-Ni, Co-Ni-P, Co-Ni
-B, Co-Ni-Al, Co-Ni-Na, Co-Ni-Ce, Co-Ni-
Cr, Co-Ni-Zn, Co-Ni-Cu, Co-Ni-W, Co-Ni-R
There are ferromagnetic metals such as e and Co-Sm-Cu.

Further, O may be contained in the composition of these magnetic thin film layers.

The thickness of such a magnetic thin film layer is 0.05 to 0.5 μm, preferably 0.07 to 0.3 μm.

Then, such a magnetic thin film layer is formed by a vapor phase or liquid phase plating method.

In the plating method used in the present invention, the surface of the object to be treated is adhered and coated with the above-mentioned thin film of ferromagnetic metal.

Then, for example, as the vapor phase plating method, a vapor deposition method, a sputtering method, an ion plating method, and in some cases, a thermal
There are CVD and plasma CVD. Liquid phase plating methods include electroless plating and, in some cases, electrolytic plating.

In the present invention, the magnetic thin film layer may be formed using any of the above methods.

The method usually used for forming the magnetic thin film layer in the above vapor phase plating method will be described in detail below.

In the vacuum evaporation method, the evaporation source is heated in a high vacuum of about 10 ^-3 Torr or less by an electron beam method, a resistance heating method or the like to melt and evaporate the evaporation source, and the above is evaporated as a thin film on the substrate surface, for example. It is a method to let. The kinetic energy obtained by the vaporized particles during this vaporization is about 0.1 eV to 1 eV.

The sputtering method can be roughly classified into a plasma method and an ion beam method, depending on the area in which the work is performed.

In the sputtering method using the plasma method, an abnormal glow discharge is generated in an atmosphere of an inert gas such as Ar, and a target (deposition material) is sputtered by Ar ions to deposit on a substrate.

Either DC sputtering in which a DC voltage of several KV is applied to the target or high frequency sputtering in which high frequency power of several hundreds to several KV is ignited may be used.

In addition to the multi-pole system from 2 poles to 3 poles and 4 poles, a direct electrode field was added to give electrons in the plasma a cycloidal motion similar to a magnetron to create a high density plasma and to lower the applied voltage to sputter. It is also possible to use a magnetron-based sputtering which is highly efficient.

If necessary, reactive or chemical sputtering using O ₂ , N ₂ or the like may be used instead of using pure inert gas such as Ar.

In the ion beam method, Ar, etc. are ionized using an appropriate ion source, extracted, extracted as an ion beam to the high vacuum side by the negative high voltage applied to the electrode, and the target material irradiated on the target surface and sputtered is deposited on the substrate. Vapor deposition. The operating pressure is about 10 ^-2 to 10 ^-3 Torr in all cases.

The kinetic energy of the deposited particles in the sputtering method is about several eV to 100 eV, and for example, that of the vapor deposition method (about 0.1 eV
It is extremely large compared to ~ 1eV).

The ion plating method is an atomistic film forming method in which a vapor deposition material is bombarded onto a substrate surface with sufficient kinetic energy before and during film formation.

Its basic functions are effects such as sputtering of the substrate by the projecting ions, heating, ion implantation, and the like, which affect adhesion, nucleation of the deposited film, and film growth. The ion plating method is broadly classified into a plasma method and an ion beam method, depending on the area in which the work is performed.

In the plasma method, after the substrate (negative potential) is cleaned by the impact of Ar ⁺ by DC glow discharge, the evaporation source is heated to vaporize the vapor deposition material, which is ionized in the plasma and the cathode of the glow discharge surrounding the substrate. Accelerated by the strong electrolysis in the dark area, it collides with the substrate and deposits it with high energy.
Many types can be used, such as a direct current application type, a high frequency excitation type, and a combination thereof and various types of heating of an evaporation source, and a plasma electron beam method using a hollow cathode plasma electron gun may be used.

In the ion beam method, the deposition material ions generated by the ion source, such as the sputter type, electron impact type or improved version of Duoplasmatron, are drawn into the high vacuum region, and the acceleration voltage is adjusted to normalize the substrate surface and deposit it. Continue. In cluster ion beam technology (vapor deposition and crystal growth), the vapor deposition material is ejected from a crucible injection nozzle into a high vacuum, and 10 ² to 10 ³ atoms are loosely bonded to each other by utilizing the supercooling phenomenon due to adiabatic expansion. Agglomeration of atoms (cluster)
Is used and ionized.

In addition, the kinetic energy of ions in ion plating is about several tens eV to 5 KeV compared to other dry coating methods such as vapor deposition (about 0.1 eV to 1 eV) and sputtering (about several eV to 100 eV). Very big. Therefore, the adhesion film formed by this method has extremely high adhesion strength. Further, since the deposition rate is extremely high, the film can be formed in a short time.

Further, an arc discharge ion plating which is recently developed as a new technique and which is ionized by thermoelectrons may be used. In the arc discharge ion plating method, the thermoelectrons emitted from the thermoelectron emission source are made to collide with the vapor flow obtained by heating the vaporization source and evaporating, when the vapor flow density near the vaporization source is relatively high. To generate ionization of the vapor stream, and the ionized vapor stream is vertically focused on the adherend by a radio wave or a magnetic field to form a film.

As the liquid phase plating method, electroless plating is usually used.

As the bath composition to be used, various known plating conditions can be applied, for example, Japanese Examined Patent Publication No. 40-8001,
No. 49-29561, No. 55-14865, No. 54-17439
Nos. 58 to 17824 and the like can be used.

In the present invention, as the composition of the magnetic thin film layer, it is preferable that Co is an essential component and Co, Co + Ni, Co + O, or Co + Ni + O.

That is, it may be composed of Co alone, or may be composed of Co and Ni.

When Co + Ni, the weight ratio of Co / Ni is preferably 1.5 or more.

Further, O may be contained in addition to Co or Co + Ni. When O is contained, more favorable results are obtained in terms of electromagnetic conversion characteristics and running durability.

In such a case, the atomic ratio of O / Co (when Ni is not included) or O / (Co + Ni) is 0.5 or less, particularly 0.15 to 0.45.
It is preferred that

On the other hand, in the magnetic thin film layer, Co, Co + Ni, Co + O or
When Cr is contained in addition to Co + Ni + O, even more preferable results are obtained.

This is because the electromagnetic conversion characteristics are improved, the output and the S / N ratio are improved, and the film strength is further improved.

In such a case, the weight ratio of Cr / Co (when Ni is not included) or Cr / (Co + Ni) is preferably 0.001 to 0.1.

In addition, in such a magnetic thin film layer, other trace components, especially fiber metal elements such as Fe, Mn, V, Zr, Nb, Ta, M
It may contain o, W, Ti, Cu, Zn and the like.

Generally, such a magnetic thin film layer is preferably an aggregate of particles having a columnar crystal structure inclined with respect to the normal to the main surface of the substrate. Thereby, the electromagnetic conversion characteristics are improved.

In such a case, the particles having a columnar crystal structure are preferably tilted within a range of 20 to 60 ° with respect to the normal line of the main surface of the substrate.

In addition, each columnar crystal grain usually has a length over the entire thickness direction of the magnetic thin film layer, and its minor axis is generally 50 to 500.
Å about

Then, Co and Ni, Cr, etc., which are added as necessary, constitute the columnar crystal itself, and when O is added, O is usually present on the surface of each columnar crystal element mainly in the form of oxide. Exists in the form.

Such a magnetic thin film layer is usually formed to a thickness of 0.05 to 0.5 μm.

The magnetic thin film layer is usually formed as a single layer, but it may be formed by laminating a plurality of layers with an intermediate layer interposed in some cases.

Such a magnetic thin film layer can be formed by the various vapor phase plating methods described above, but it is usually preferable to form the magnetic thin film layer by the oblique deposition method.

As the oblique vapor deposition method used, a known oblique vapor deposition method may be used, and the minimum value of the incident angle with respect to the normal to the substrate is preferably 30 ° or more.

The vapor deposition conditions and the post-treatment method may be according to known conditions and methods. In this case, effective post-treatment methods include various known treatments for introducing O into the magnetic thin film layer.

When forming a metal oxide film on the surface of the magnetic thin film layer, various oxidation treatments are possible.

Further, the above-mentioned magnetic thin film layer can be formed on the above-mentioned plasma polymerized film through an underlayer, but in this case, the underlayer used is an alloy of aluminum, copper, titanium, chromium or the like. May be formed by ion plating or the like.

Alternatively, a resin may be applied. In this case, the resin layer may contain fine particles.

The material of the substrate used in the magnetic recording medium of the present invention is not particularly limited as long as it is a non-magnetic plastic, but is usually polyethylene terephthalate, polyester such as polyethylene 2,6-naphthalate, polyamide,
Polyimide, polyphenylene sulfide, polysulfone, wholly aromatic polyester, polyether ether ketone, polyether sulfone, polyether imide, etc. are used. Further, the shape, size, and thickness are not limited, and may be selected depending on the application.

Further, the magnetic recording medium of the present invention may have various known top coat layers on the magnetic thin film layer.

The plasma-polymerized film as described above can also be used as the top coat layer.

Further, various known back coat layers may be provided on the back surface of the substrate (the surface on which the magnetic thin film layer is not provided).

V. Specific Action and Effect of the Invention According to the present invention, as a more preferable embodiment, a plasma-treated film having a predetermined composition and a plasma-polymerized film having a film thickness of 5 to 80 Å is directly formed on the plasma-polymerized film. Alternatively, a ferromagnetic metal thin film layer is formed by a vapor phase or liquid phase plating method via an underlayer to form a magnetic recording medium.

Therefore, durability and scratch resistance are remarkably improved.

As a result of the improvement in scratch resistance, there is a merit that the still durability under low temperature and low humidity is significantly improved.

Such magnetic recording media are widely used as various information recording media.

VI Specific Examples of the Invention Hereinafter, the present invention will be described in more detail by showing specific examples of the invention.

Example 1 A substrate made of polyethylene terephthalate (PET) having a thickness of 12 μm was placed in a vacuum chamber and, while being continuously transported, a vacuum of 10 ⁻³ Torr was once drawn, and then O ₂ was used as a processing gas and Ar was used as a carrier gas. Used, O ₂ content: 10%, flow rate: 50 ml /
While maintaining the gas pressure at 0.1 Torr, the plasma was generated by applying a high frequency voltage of 100 KHz, and the substrate surface was plasma-treated.

A plasma-polymerized film was formed on the substrate under the following conditions by using the substrate whose surface was plasma-treated or untreated in this way.

Elemental analysis of these plasma polymerized films was measured by SIMS,
The film thickness was measured with an ellipsometer.

 The results are shown in Tables 1 and 2.

A ferromagnetic metal thin film layer shown below was formed on the plasma-polymerized film thus formed.

(Formation of ferromagnetic metal thin film layer) Magnetic thin film layer 1 The substrate on which the plasma-polymerized film is formed is moved along the circumferential surface of the cooling can on the cylinder, and O ₂ + Ar (volume ratio 1: 1) is set at 8 per minute.
The alloy consisting of Co80 and Ni20 is melted in a chamber whose flow rate is 00cc and the degree of vacuum is 1.0 × 10 ^-4 Torr.
Diagonal vapor deposition only at 90 ° to 30 °, Co-film with a thickness of 0.15 μm
A Ni-O thin film was formed.

Magnetic thin film layer 2 Co-Cr (composition Co 80 wt% -Cr 20 wt%) was sputtered to a thickness of 0.2 μm on a substrate on which a plasma polymerized film was formed.

Magnetic Thin Film Layer 3 Electroless plating was performed on the above-mentioned substrate on which the plasma polymerized film was formed by the following method.

(1) Activator Distilled water 55 parts Concentrated hydrochloric acid 30 parts PN-PS (World Metal Co.) 15 parts 40 ° C, 1 minute (2) Accelerator distilled water 80 parts Concentrated sulfuric acid 20 parts Room temperature, 1 minute (3) Electroless Plating bath Cobalt sulphate 0.06mol / Nickel sulphate 0.04mol / Sodium hypophosphite 0.2mol / Rothcel salt 0.5mol / Boric acid 0.2mol / Ammonium sulphate 0.5mol / NaOH alkalized pH9.5 70 ℃ 2 minutes Thickness of deposited thin film The thickness was 0.15 μm.

 The Co / Ni composition ratio in the thin film was 6/4.

The obtained tape was cut into 1/2 inch width to obtain a video tape.

 The characteristics of each of these samples were measured.

 The measurement of the characteristics is as follows.

(1) Output drop The output drop (dB) after running 200 buses was measured using a VCR at 20 ° C and 60% relative humidity.

(2) Scratch resistance test Continuous scratch strength tester (TYPE- manufactured by Shinto Scientific Co., Ltd.)
HEIDON-18) was used to measure the vertical load that scratches enter.

As the evaluation value, the ratio W / W _o of the scratch vertical load W of the medium sample having the plasma polymerized film to the scratch vertical load W _o of the medium sample having no plasma polymerized film was shown.

 The evaluation of the values is performed by comparing the same magnetic layer.

(3) Still endurance time Using a video deck in an environment of −10 ° C., the time until the output decreased by 70% in the still state compared to the initial time was examined.

From these results, the effect of the present invention is clear.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a plasma processing apparatus using DC, AC, and variable frequency power supplies. Explanation of symbols 53 …… Mixer 54 …… DC, AC and variable frequency power supply 57 …… Liquid nitrogen trap 58 …… Oil rotary pump 511,512 …… Process gas source 521,522 …… Mass flow controller 561,562 …… Feed and take-up roll

Claims (2)

(57) [Claims] 1. A substrate containing C, H, N and O, a C content of 30 to 90 at% and an atomic ratio of H / C of 1/6 to 1, N / C.
Has a plasma polymerized film with a film thickness of 5 to 80 Å with 1/20 to 3/10 and O / C of 1/20 to 3/10, and directly or through an underlayer on the plasma polymerized film. A magnetic recording medium having a ferromagnetic metal thin film layer formed by a vapor phase or liquid phase plating method. 2. A plasma-treated substrate containing C, H, N, and O with a C content of 30 to 90 at% and an atomic ratio of H /
It has a plasma polymerized film with a film thickness of 5 to 80Å in which C is 1/6 to 1, N / C is 1/20 to 3/10, and O / C is 1/20 to 3/10. A magnetic recording medium having thereon a ferromagnetic metal thin film layer formed by a vapor phase or liquid phase plating method directly or through an underlayer.