JPH06338086A - Production of magneto-optical disk - Google Patents

Abstract

PURPOSE:To coat a plastic substrate with a cured UV-curing resin under satisfactory adhesion by subjecting a face of the substrate opposite to a recording layer to undercoating with organopolysilazane having structures each represented by a specified formula and top coating with a UV-curing resin and then carrying out UV curing. CONSTITUTION:When a magneto-optical disk with a perpendicular magnetic recording layer on the plastic substrate is produced, a face of the substrate opposite to the recording layer is subjected to under-coating with organopolysilazane having both structures represented by formulae I, II and top coating with a UV-curing resin and then UV curing is carried out. In the formulae I, II, R<1> is H or methyl, R<2> is a 3-6C divalent hydrocarbon group, R<3> is methyl or phenyl and 0<=a<=2. The plastic substrate is covered with the UV-curing resin under satisfactory adhesion and the objective unscrachable magneto-optical disk not causing the problem of wettability or adhesion and less liable to an error in electric signal is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magneto-optical disk, and more particularly to a method for manufacturing a magneto-optical disk in which a UV curable resin coating is adhered onto one main surface of a plastic substrate with good adhesion.

[0002]

2. Description of the Related Art At present, plastic materials are widely used as substrate materials for magneto-optical disks. Polycarbonate resin, which is a typical material, has the advantages of excellent heat resistance and small deformation due to water absorption, but it is easily scratched because the resin itself has low hardness, and because it is a dielectric substance However, there is a problem in that an electrostatic charge is likely to be attached, which causes an error in an electric signal.

For this reason, a hard coat having an antistatic function is applied to the surface of the substrate opposite to the recording film formed on the substrate, and the hard coat material is transparent. UV curable resins and inorganic materials are conceivable, but because they are cheap and simple, U such as epoxy, methacrylic, urethane
V-curable resin is used.

[0004]

However, since this UV-curable resin has problems in wettability and adhesion with a plastic substrate, the substrate before the UV-curable resin coating is subjected to a primer treatment, Although the adhesion has been improved and attempts have been made to improve the UV curable resin itself, none of them has been able to achieve a satisfactory effect.

[0005]

The present invention relates to a method of manufacturing a magneto-optical disk which solves the above disadvantages and problems, and to manufacture a magneto-optical disk having a perpendicular magnetic recording layer on a plastic substrate. In the method, on the surface of the plastic substrate opposite to the recording layer, a formula represented by the general formula (I)

[Chemical 3] (Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a divalent hydrocarbon group having 3 to 6 carbon atoms, R ³ is a methyl group or a phenyl group, and a is 0 ≦ a ≦ 2). − (C
_{H 3) 2 Si (NH)} - primed the organopolysilazanes containing structure at the same time represented by, and is characterized in that UV curing was then overcoated with a UV curable coating.

That is, as a result of various investigations by the present inventors to develop a method for manufacturing a magneto-optical disk in which a plastic substrate and a UV-curable resin coating are in close contact with each other, the U
Before coating the plastic substrate with the V-curable resin, the surface of the plastic substrate opposite to the recording layer is previously shown with a group represented by the general formula (I) and-(CH ₃ ) ₂ Si (NH)-. When the undercoating of organopolysilazane containing at least one group is formed, the plastic base material and the chemical bond layer of the silazane are formed here. Therefore, when the UV-curable resin is overcoated on this, the UV-curable resin layer is formed. It was found that the plastic substrate can be coated with good adhesion, and according to this, it was confirmed that the UV-curable resin can be coated on the plastic substrate with good adhesion, and that the hub made of the UV-curable resin can be bonded with good adhesiveness. Completed the invention.
This will be described in more detail below.

[0007]

The present invention relates to a method of manufacturing a magneto-optical disk, which has the structure represented by the general formula (I) and the formula-(CH ₃ ) ₂ Si (NH)-, which is characterized in that an organopolysilazane simultaneously containing a structure represented by the formula ( ₂ ) is undercoated, and then a UV-curable coating agent is overcoated and UV-cured. Since the curable coating agent can be coated on the plastic substrate with good adhesion, it is possible to prevent the plastic substrate from being scratched and preventing dust and the like from electrostatically adhering. The advantage is given that it can be low in error.

The present invention relates to a method for manufacturing a magneto-optical disk, which is a gist of a method for coating a surface of a plastic substrate opposite to a surface on which a recording layer is formed with a UV curable coating agent with good adhesion. is there. The structure of the magneto-optical disk itself may be a known one. Therefore, the magneto-optical disk may be made of SiN as a first dielectric layer on the surface of a plastic substrate having guide grooves made of polycarbonate resin, polyolefin resin, acrylic resin or the like. , AlN, SiC layer, etc., and thereafter, a recording layer made of TbFe, TbFeCo, etc. is provided thereon as a single layer or a laminate of two or more layers, and further on top of this, a second dielectric layer same as the first dielectric layer is provided. A body layer may be provided, and finally, a reflection layer made of a simple substance such as Al, Cu, or Ag or an alloy may be provided. However, this should be provided by further providing an organic protective layer on this reflection layer. Is preferred.

In the present invention, a UV-curable coating layer is provided on the opposite surface of the recording layer of the plastic substrate of the magneto-optical disk thus manufactured. Before applying the UV-curable coating agent, the UV-curable coating layer is formed. A plastic substrate is primed with organopolysilazane. Thus, this organopolysilazane has the formula (I)

[Chemical 4] R ¹ is a hydrogen atom or a methyl group, R ² is a divalent hydrocarbon group having 3 to 6 carbon atoms such as a propylene group, a butylene group, an amylene group and a hexylene group, and R ³ is a methyl group or a phenyl group. Where a is a structure having a structure of 0 ≦ a ≦ 2 and a structure represented by the formula — (CH ₃ ) ₂ Si (NH) — at the same time, for example,

[Chemical 5] Are required to be shown.

The primer treatment of the plastic substrate by undercoating the organopolysilazane on the plastic substrate may be carried out by a spin coating method, a dipping method, a spray method or the like. Since a chemical bond layer is formed on the surface of the plastic substrate, epoxy-based, acrylic-based, methacrylic-based, urethane-based, or other UV-curable resin is overcoated onto the plastic substrate through the chemical bond layer. As a result, it has the advantage that it is coated on the plastic substrate with good adhesion and therefore there is no problem of wettability or adhesion here.

Since the UV curable resin is cured by UV, it can be easily cured by irradiating the coating with ultraviolet rays from a mercury lamp or the like. However, this organopolysilazane is used. May be applied to the adhesive surface of the hub and the adhered surface of the disk, which gives the advantage that the hub can be adhered with good adhesion by the UV curable resin.

[0012]

EXAMPLES Next, synthesis examples and examples of the organopolysilazane used in the present invention will be described. (Synthesis Example) Ammonia gas was flowed into a hexane mixed solution of 3-methacryloxypropyltrichlorosilane and dimethyldichlorosilane, and ammonium chloride produced as a by-product was filtered under a nitrogen gas atmosphere.

[Chemical 6] A solution of organopolysilazane in hexane was obtained.

EXAMPLE A transparent polycarbonate substrate having guide grooves was first coated with a first
After sputter-depositing a SiN film as a dielectric layer to a thickness of 1,000Å, sputter-deposit a TbFeCo film as a recording layer to a thickness of 200Å on this as a second dielectric layer. Of SiN film is sputter-deposited to a thickness of 350Å, and an Al film as a reflection layer is sputter-deposited to a thickness of 500Å, and an acrylic U film is formed on this sputtered film.
Spin-coat V-curable resin and UV-cure it to 10μ
Then, a coating layer of m was prepared to make a magneto-optical device.

Then, a hexane solution of the organopolysilazane synthesized in the above-mentioned synthesis example was spin-coated on the surface of the polycarbonate substrate of this magneto-optical device opposite to the recording layer, and then an acrylic UV-curable resin was spun thereon. A coating layer having a thickness of 5 μm is formed by coating and UV curing, and for comparison, a polycarbonate substrate is directly spin-coated with an acrylic UV curing resin without using organopolysilazane, and UV curing is performed to form a coating layer. Had made.

Next, the acrylic UV thus obtained
The adhesive strength of the acrylic UV-curable resin on the magneto-optical disk coated with the polycarbonate group with the curable resin was evaluated by the cross-cut tape method immediately after the production and after the 2,000-hour durability test at the temperature of 80 ° C and the humidity of 85%. The results shown in Table 1 below were obtained.

[0016]

[Table 1]

[0017]

The present invention relates to a method of manufacturing a magneto-optical disk, which is a magneto-optical disk having a perpendicular magnetic recording layer on a plastic substrate, as described above, on the surface of the plastic substrate opposite to the recording layer. To undercoat an organopolysilazane containing a structure represented by the general formula (I) and a structure represented by the formula — (CH ₃ ) ₂ Si (NH) — at the same time, and then top coat with a UV curable resin for UV curing. According to this, since a chemical bonding layer is formed between the plastic substrate and the silazane by the undercoat of the organopolysilazane, the above-mentioned U is overcoated.
The V-curable resin is coated on the plastic substrate with good adhesiveness, so that problems of wettability and adhesiveness do not occur here, the hardness of the plastic substrate is improved, and scratches do not occur, and dust etc. Is no longer electrostatically deposited, which provides the advantage of reduced errors in the electrical signal.

Claims (3)

[Claims] 1. A method for manufacturing a magneto-optical disk having a perpendicular magnetic recording layer on a plastic substrate, wherein the surface of the plastic substrate opposite to the recording layer is represented by the formula: (Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a divalent hydrocarbon group having 3 to 6 carbon atoms, R ³ is a methyl group or a phenyl group, and a is 0 ≦ a ≦ 2). − (C
_{H 3) 2 Si (NH)} - primed the organopolysilazanes containing structure at the same time represented by, and then the production method of the magneto-optical disk, characterized in that the UV curing overcoated with a UV curable resin. 2. The organopolysilazane has the formula: (Here, R ¹ is a hydrogen atom or a methyl group, R ² is a divalent hydrocarbon group having 3 to 6 carbon atoms, R ³ is a methyl group or a phenyl group, a is 0 ≦ a ≦ 2, and x is 0 <x ≦. 0.8, y is 0 <y
The manufacturing method of the magneto-optical disk according to claim 1, wherein ≦ 0.8). 3. The method of manufacturing a magneto-optical disk according to claim 1, wherein an undercoat of organopolysilazane is applied to the bonding surface of the hub and the surface to be bonded on the disk, and then the hub is bonded with a UV curable resin.