JPH035918A - Substrate for magnetic recording medium - Google Patents

Abstract

PURPOSE:To form a hard alloy film essentially comprising Ni-P having excellent adhesion property on a synthetic resin substrate by injecting metal ions in the surface area of the substrate and forming the alloy film essentially comprising Ni-P. CONSTITUTION:A metal ion injection layer 2 is formed by injecting metal ions in the surface area of a synthetic resin substrate 1, on which an alloy film 3 essentially comprising Ni-P is formed. By injecting metal ions in the surface area of the resin substrate, the alloy film 3 can be formed with good adhesion by wet plating. Thereby, the obtd. substrate 1 for magnetic recording medium has a surface film of high hardness with excellent adhesion property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a substrate for L magnetic recording media, and more specifically, an alloy containing Ni-P as a main component on the surface of a synthetic resin substrate. The present invention relates to a magnetic recording medium substrate formed by forming a magnetic recording medium.

[Prior Art] In recent years, studies have been made to use synthetic resin substrates as substrates for magnetic recording media. Synthetic resin substrates are lighter than aluminum alloy substrates, more resistant to impact, and easier to process. Furthermore, in the case of synthetic resin substrates, attempts have been made to form a highly hard coating on the surface of the substrate in order to improve the hardness of the substrate surface and obtain sufficient CSS characteristics and scratch resistance. Conventionally, the following types of synthetic resin substrates having a highly hard coating formed on their surfaces have been known, for example.

■Technology disclosed in Japanese Patent Application Laid-Open No. 59-213025 This uses a mixed composition of ABS resin and/or MBS resin and polycarbonate resin as the synthetic resin forming the substrate, and an alloy mainly composed of Ni-P. A film is formed on the synthetic resin substrate by a wet plating method.

That is, by using a mixed composition of ABS resin or the like and polycarbonate resin as the synthetic resin forming the substrate, Ni-P, which has been known for a long time as a coating for improving the surface hardness of aluminum alloy substrates, can be used. This makes it possible to use the alloy coating as a surface coating.

An alloy film containing Ni--P as a main component has characteristics such as being highly hard and non-magnetic, and being wet-plated with excellent mass productivity.

(2) Technique disclosed in Japanese Patent Application Laid-open No. 187117/1983 This technique forms a film of Ti or a Ti compound on the surface of a synthetic resin substrate using an ion blasting method. Such a method can also improve the hardness and roughness of the substrate surface.

[Problems to be Solved by the Invention] However, the conventional magnetic recording medium substrates described above have the following problems:
The following issues were encountered.

■The technology disclosed in Japanese Patent Application Laid-open No. 59-213025 has a technique in which the resin used for forming the substrate is KBS resin and/or KBS resin.
Alternatively, since it is limited to a mixed composition of MBS resin and polycarbonate resin, there is a problem that the use of resins with better moldability and heat resistance (flamed resins) is restricted.

In addition, when ABS resin is mixed as a substrate raw material, the heat resistance of the substrate decreases, so there is a problem that it is difficult to use a method that requires heat resistance such as sputtering when forming a recording film. .

Furthermore, in this magnetic recording medium substrate, the surface of the substrate is roughened during the formation of the plating layer to improve the adhesion between the substrate and the plating layer, but the adhesion obtained by this method is insufficient for magnetic recording. It cannot be said that it is sufficient for practical use as a medium, and improvement in adhesion has been desired.

■The technology shown in JP-A No. 61-187117 requires the formation of a Ti or Ti compound coating of several micrometers in order to obtain the necessary hardness when used as a magnetic recording medium. In order to form a film by the ion blasting method, a long time is required, which causes a problem of high cost. Furthermore, there is also a problem in that the resin magnetic recording substrate suffers from a great deal of thermal damage during film formation, which causes deformation of the substrate.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a synthetic resin substrate for a magnetic recording medium that is excellent in heat resistance and adhesion and has high surface hardness at a low cost.

[Means for Solving the Problems] The gist of the present invention is to provide at least Ni
- A substrate for a 6fi recording medium formed with an alloy film mainly composed of P, wherein at least one type of metal ion is implanted near the surface of the synthetic resin substrate to form a metal ion implantation layer. A substrate for a magnetic recording medium is provided, characterized in that a sample of the alloy containing Ni--P as a main component is formed on the metal ion implantation layer.

Hereinafter, the configuration of the present invention will be explained in detail.

(Synthetic resin substrate) The synthetic resin substrate used in the present invention may be one of acrylic, polycarbonate, polyimide, epoxy, etc. or 2F! Those formed from the above mixed resins can be used. Also, glass iaf &
, fillers such as alumina particles.

(Injection of metal ions) In the present invention, ions are implanted into the synthetic resin substrate.

Ionizability is tX 10-5Torr~lX
It is preferable to perform this under a vacuum of about 10 Torr.

The ion species to be implanted may be any metal as long as it can be ionized, but it is preferable to use a nonmagnetic metal. This is to avoid impairing the positive recording and reproducing characteristics when a magnetic recording medium formed using the magnetic recording medium substrate of the present invention is actually used. Roughly, by the steps described below, N i-P
Since a wet plating method is used to form an alloy film mainly composed of , it is preferable to implant ionic species that are less likely to contaminate the bath. Examples of ion species that rarely contaminate the bath include A.degree. C., Au, Cu, and Mo.

The acceleration voltage during ion implantation is preferably within the range of 10 kV to IOMV. This is because if it is less than 10 kV, the energy given to the ions is too small and sufficient ion implantation cannot be performed, and if it is more than IOMV, the ion-implanted surface becomes brittle and the This is because the adhesion to the first pattern decreases. The amount of ions implanted under these conditions is 10'3/Cm2
It is preferably within the range of ~1020 pieces/cm2.

The thickness of the ion implantation layer formed by ion implantation is 5
Preferably, the number is within the range of 00 to 000 people.

This is because the desired performance (surface hardness, C
SS characteristics, adhesion with Ni-P plating layer, etc.) were not exhibited, and too.

This is because even if you surpass humans, not only will your performance not improve any further, but your productivity will actually deteriorate.

(Alloy coating mainly composed of Ni-P) Next, in the present invention, an alloy coating mainly composed of Ni-P is formed on the ion-implanted synthetic resin substrate.

As a method for forming an alloy film containing Ni-P as the main component,
For example, a wet plating method can be used. Among these, the electroless plating method is particularly preferred because it allows mass production of an M film with a uniform thickness.

The thickness of the alloy film mainly composed of Ni-P is 2 μm to 20 μm.
Preferably it is μm. This is because the desired performance (surface hardness, C3S properties, etc.) cannot be achieved with a thickness of 2 μm or more.
This is because, even if the thickness exceeds 20 μm, not only the performance will not improve any further, but also the productivity will deteriorate.

Note that texturing processing may be performed to improve the C5S characteristics.

[Function] According to the present invention, since metal ions are implanted into the surface of the substrate formed of synthetic resin, Ni-P is added to the surface of the substrate.
An alloy film mainly composed of can be formed with good adhesion by a wet plating method. That is, it becomes possible to obtain a substrate for an iB magnetic recording medium having a highly hard surface coating with excellent adhesion. Note that, since excessive heat is not generated during ion implantation, problems such as thermal deformation of the synthetic resin substrate do not occur.

Furthermore, the magnetic recording medium substrate of the present invention can be manufactured at a very low cost because it can be manufactured without major changes to the Ni-P plating process used to manufacture conventional aluminum alloy substrates. can be manufactured.

[Example] Hereinafter, one example of the present invention will be described. In this example, as an example of a magnetic recording medium substrate, t
The case of an n-air disk substrate will be explained.

FIG. 1 is a schematic cross-sectional view showing an LA air disk substrate according to this embodiment. In the figure, 1 is a polyetherimide substrate as a synthetic resin substrate, 2 is a J envelope containing metal ions of the synthetic resin substrate (A°C ions were used as metal ions), and 3 is an NL-P alloy coating. .

The magnetic disk substrate according to this example was manufactured as follows.

■A polyetherimide substrate was produced by injection molding.

(2) ALL ions were implanted into this substrate using an ion implantation device to form an ion implantation layer with a thickness of 5,000 ions.

A℃ ion implantation was performed in a vacuum atmosphere of I x 10-6 Tart at an accelerating voltage of 800 kV, and the implantation amount was 1.
0'6 pieces/cm'.

■Ni 85wt%-P1 with a thickness of 10μm on this substrate
A 5 wt % alloy film was formed using an electroless plating method.

Through the above steps, a magnetic disk substrate according to this example was obtained.

As a result of measuring the surface hardness of the thus obtained magnetic disk substrate by the micro-Vickers method, it was found that the load was 25 g.
It was 750.

Next, the Ni-
The adhesion strength of the P alloy film was evaluated. For comparison, Ni-P alloy without ion implantation? ! A similar evaluation was performed on a magnetic disk substrate on which a film was formed (that is, a magnetic disk substrate prepared without going through the above step (2) and with all other conditions being the same). These results are shown in Table 1.

As is clear from Table 1, in the 61-air recording medium substrate of this example, the Ni--P alloy coating did not peel off at all, and its adhesion strength was found to be very excellent.

Although the case of the magnetic disk substrate shown in Table 1 has been explained as an example, similar results were obtained with substrates used for other magnetic recording media.

[Effects of the Invention] As explained above, according to the present invention, it is possible to form a high-hardness alloy film mainly composed of Ni-P with excellent adhesion on the surface of a synthetic resin substrate, which makes it lightweight. Therefore, it becomes possible to provide a substrate for a TL magnetic recording medium that has excellent reliability and is easy to mass-produce.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a magnetic disk substrate according to this embodiment. 1... Polyetherimide substrate as a synthetic resin substrate, 2... Metal ion implantation layer of synthetic resin substrate, 3...
・Ni-P alloy coating.

Claims (2)

[Claims] (1) A magnetic recording medium substrate formed by forming an alloy film containing at least Ni-P as a main component on a synthetic resin substrate, wherein at least one type of metal ion is present near the surface of the synthetic resin substrate. 1. A substrate for a magnetic recording medium, characterized in that a metal ion implantation layer is formed by implanting Ni--P, and an alloy film containing Ni--P as a main component is formed on the metal ion implantation layer. (2) The substrate for a magnetic recording medium according to claim 1, wherein the metal ions injected into the synthetic resin substrate are nonmagnetic metal ions.