JPS6192426A - Specular surface substrate - Google Patents

Abstract

PURPOSE:To obtain a specular surface substrate for a magnetic memory or optical memory having the characteristics of both of a metallic plate which has excellent rigidity and heat resistance and a synthetic resin with which a specular surface characteristic is easily obtainable and having the excellent specular surface characteristic, rigidity and heat resistance by combining the above-mentioned metallic plate, etc. and the synthetic resin. CONSTITUTION:The metallic plate or the like 1 is a metallic plate such as iron plate and aluminum plate or ceramic plate, glass plate, etc. and the plate having about 1-3mm thickness is usually used. The undercoat resin layer 2 to be formed on the surface of the roughened surface of the metallic plate 1 or the like is not particularly limited as far as said layer has the excellent adhesiveness to the metallic plate, etc. and the resin layer on the surface and is preferably urethane and epoxy resins. The surface of the metallic plate or the like is roughened to increase the adhesiveness between an undercoat resin and the metallic plate or the like. The synthetic resin layer 3 forming the surface layer has a specular surface 3a thereon. Thermosetting resins such as epoxy resin, urethane resin and imide resins are usable as the synthetic resin. The epoxy resin in particular is highly resistant to heat and has excellent hardness, light resistance, etc. and is therefore adequately used for the substrate for the magnetic memory and optical memory.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a magnetic memory or optical memory substrate that has excellent specularity and rigidity by combining a synthetic resin and a metal plate. be.

[Prior art] Synthesis of glass substrates, aluminum, metal substrates such as Starbucks, acrylic resins, epoxy resins, etc. as mirror substrates for magnetic or optical memories with good surface precision +1
There is something like a fat substrate. However, in the case of glass substrates, a polishing process that requires a large amount of man-hours is required to obtain surface precision, and they also have drawbacks such as being easily broken and being sensitive to high temperatures. In the case of metal substrates, a large number of man-hours are required for the polishing process to obtain surface precision. On the other hand, in the case of a synthetic resin substrate, it is relatively easy to obtain excellent specularity by transferring from a specular mold, but there is a drawback in rigidity.

Substrates have been proposed that combine the features of both metal plates and synthetic resin by combining them, but the adhesion between the two is insufficient and the resin layer may crack due to repeated heating and cooling. There is.

[Objective of the Invention] The present invention combines the features of both, by combining a metal plate with excellent rigidity and heat resistance with a synthetic resin that easily provides specularity. The purpose of the present invention is to provide a mirror substrate for magnetic memory or optical memory with excellent heat resistance.

[Structure of the Invention] As shown in FIG.
This mirror-finished substrate for magnetic memory or optical memory is characterized by comprising a resin layer (3) having a mirror surface (3a) formed on the surface of a tel resin layer (2) and an undercoat resin layer.

In the present invention, the metal plate, etc. (1) may be a metal plate such as an iron plate or an aluminum plate, a ceramic plate, a 2-layer plate, etc., and the thickness may vary. Use one with a diameter of about 1 to 3 mm. The undercoat resin layer (2) formed on the surface of the roughened metal plate, etc. (1) is not particularly limited as long as it has excellent adhesion to the metal plate, etc. and the resin layer on the surface, but urethane-based , epoxy resin is good. The thickness of the undercoat layer is preferably 200 μW or less, particularly preferably 5011 m or less.

In order to strengthen the adhesion between the undercoat resin and the metal plate, the surface of the metal plate, etc. is roughened. The roughening method is
Coarse polishing with sandpaper, etc., or fine lumi powder,
This is done using a dry or wet blasting method in which metal powder, glass powder, etc. are strongly collided with each other. By roughening the surface, the undercoat resin digs into the uneven surface, resulting in stronger adhesion. Surface roughness is Rmax6.5-
Approximately 10 μm is good.

The synthetic resin layer (3) forming the surface layer has a mirror surface (3a
). As the synthetic resin, thermosetting resins such as epoxy resins, urethane resins, and imide resins can be used. In particular, epoxy resin has excellent heat resistance, hardness, light resistance, etc., and is therefore suitably used for magnetic memory and optical memory substrates. Although any epoxy resin can be used, it is preferable to use an epoxy resin containing an acid anhydride curing agent, an amine curing accelerator, and, if necessary, an antioxidant, a light stabilizer, etc. due to the above-mentioned characteristics. To obtain a mirror-like surface, the most common method is to place a roughened metal plate in a mirror-finished glass mold or metal mold, and then pour liquid resin onto it. Not limited.

The thickness of this synthetic resin layer is usually 0.02 to 0.5 mm.
That's about it.

[Effect of the invention 1] The mirror substrate of the present invention has rigidity due to the metal plate etc., excellent surface precision due to the synthetic resin, and excellent heat resistance due to the composite of the metal plate etc. and these resins. It is used as a substrate for magnetic memory, a master disk for optical memory, or a substrate.

Since the surface of the metal plate etc. is roughened, it has excellent adhesion with the undercoat layer, and even in cold and hot cycles, the effect of the undercoat layer and the synthesis ↑h (crank does not enter the fat layer). do not have.

[Embodiment 1] An embodiment of the configuration shown in FIG. 2 will be described. Diameter 130
mm, inner diameter 40 mm, thickness 1.6 mm, and the surface roughness is Rm by spraying fine lume powder with a blasting machine in advance.
Aluminum plate whose surface has been roughened to approximately 8.0 μm ax (
1) A thickness of 50μ formed on both sides of the aluminum plate.
Epoxy U (fat layer, undercoat resin layer (2), and acid anhydride-cured epoxy resin layer (3) with a thickness of 100 μm formed on the undercoat resin layer, with a thickness of 1.9 m)
This is a substrate for optical memory of mm. This substrate was obtained as follows. Glass mold with mirror-finished inner surface (surface roughness Rmaxo, 01-0.02μm, flatness 15-20μm)
m) and an undercoat resin layer (2) inside this.
An aluminum plate (1) provided with the above was placed, and the epoxy resin (liquid) was cast and cured at 90°C.

The obtained substrate had the following characteristics.

Surface roughness Rmaxo, 01-0.0271+Flatness 15-20μm Substrate thickness 1.9±0.02mm Heat resistance 180℃ Repeated heating and cooling test 50 cycles or more For comparison, an aluminum plate with no surface roughening (
An optical memory substrate was obtained in the same manner as in the example except that a surface roughness Rmaxo of about 5 μm was used. The characteristics of this substrate were as follows.

Surface roughness Rmaxo, 01-0.02 um Flatness 15-20 μm Substrate thickness 1.9±0.02n++n Heat resistance 1
80°C Heating/cooling repeated test Synthesis in one cycle (cracks occur on the material surface)Heating: 125°C3 repeated heating/cooling test
A cycle of cooling knee at 40° C. for 30 minutes was repeated, and judgment was made based on the presence or absence of cracks.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of the substrate of the present invention. 1: Roughened metal plate, etc. 2: Fat layer for undercoat 3: Synthetic resin layer 3a: Mirror surface

Claims (1)

[Claims] A composition having a circular plate-like body such as a roughened metal plate (hereinafter referred to as metal plate, etc.), an undercoat resin layer formed on both or one side of the metal plate, etc., and a mirror surface formed on the surface of the undercoat resin layer. A mirror substrate for magnetic memory or optical memory, characterized by comprising a resin layer.