JPS61104441A - Production of substrate for master disk of optical disk - Google Patents

Abstract

PURPOSE:To obtain a substrate for a master disk of an optical disk having the advantages of a plate-shaped body having excellent rigidity and a synthetic resin with which a specular surface is easily obtainable, i.e., a substrate having the excellent specular surface characteristic, rigidity and heat resistance by combining both of the plate-shaped body and synthetic resin. CONSTITUTION:The plate-shaped body 1 is a metallic plate such as iron plate or aluminum plate or ceramic plate, etc. having 2-10mm thickness and an undercoat resin layer 2 is preliminarily provided on the surface of said body. The undercoat resin is not particularly limited as far as said resin has the excellent adhesiveness to the plate-shaped body and resin film. Urethane and epoxy resins are preferably used for said resin. The resin which provides a cured material having excellent heat resistance and hardness is preferable as the liquid resin for forming the surface resin layer and for example, a hard epoxy resin is suitabe. The liquid resin is made to exist at a proper ratio on the plate-shaped body by coating, etc. and the liquid resin having 50-10,000cp is more preferable although the viscosity is not particularly limited. For example, the metallic plate or glass plate having the specular surface is preferably used for the specular surface plate and the weight to be exerted to the body 1 is preferably about >=0.5g/cm<2>. Weighing by a suitable means is equally satisfactory when the specular surface plate itself is not enough in weight. The thin film of the resin is formed when the specular surface plate is imposed on the liquid resin. The excess resin is discharged from the periphery of the plate-shaped body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for manufacturing an optical disc master substrate with excellent specularity and rigidity by combining a synthetic resin and a plate-like body. be.

EPrior Art J A glass plate with a thickness of 3 to 10 a+m and having good specularity is used as a substrate for a master of an optical disc. In the case of L-gold and plastic plates, they are susceptible to impact and require a polishing process that requires a lot of man-hours to achieve a mirror finish.Furthermore, mold may form due to the influence of moisture in the air during storage. A deterioration phenomenon occurs. A synthetic resin substrate may be considered as an alternative to this, but in this case, although it is relatively easy to obtain excellent specularity by transferring from a specular mold, it is less effective than glass. Rigidity is weak.

[Object of the Invention] The present invention provides a substrate for an optical disk master that combines the VF characteristics of both, by combining a plate-like body with excellent rigidity and a synthetic resin that can easily obtain a mirror surface, that is, a mirror surface. strength, rigidity,
An object of the present invention is to provide a method for manufacturing a substrate for an optical disc master having a thickness of 3 to 10 mm and having excellent heat resistance.

[Configuration 1 of the Invention The present invention provides a method for manufacturing an optical disc master substrate comprising a plate-like body (1) and a resin thin film (3) formed on the surface thereof as shown in FIG. For example, as shown in FIG.
) by applying an appropriate amount of liquid resin to the plate-like body ( After forming a thin resin layer on 1) and curing the liquid resin in this state,
A substrate for an optical disk master comprising a plate-like body and a resin thin film, characterized in that a mirror-like resin thin film (3) is formed on a plate-like body (1) by peeling off a mirror-like plate (4). This is the manufacturing method.

The plate-like body (1) used in the present invention has a thickness of 2 to 10
metal plates such as iron plates, aluminum plates, ceramic plates, etc.

An undercoat resin layer (2) is applied to the plate surface in advance.
It is preferable to provide The 7-foot resin is not particularly limited as long as it has excellent adhesion to the plate-shaped body and the resin film, but urethane-based and epoxy-based resins are preferably used.

The liquid resin for forming the surface resin layer is preferably one that provides a cured product with excellent heat resistance and hardness; for example, a hard epoxy resin is suitable.

A suitable amount of the liquid resin is made to exist on the plate-shaped body by coating or the like.

The viscosity of the liquid resin is not particularly limited, but is 50 to 10,000.
Those with cP are preferred. For example, a mirror plate is a metal plate with a mirror surface or a glass plate (which is often used), and a plate-like plate (
The weight related to 1) is preferably about 0.5 g/am2 or more. Of course, if the mirror plate itself is insufficient in weight, it may be weighted by appropriate means. Place the mirror plate on the liquid resin i! When placed, a thin film of attenuated fat is formed, and excess resin is discharged from around the plate.

In addition, when the thickness of the resin thin film is relatively thick, a spacer for adjusting the thickness may be used between the table on which the plate-shaped body is placed and the mirror plate.

In this way, a resin thin film having a thickness of 1 mm or less, preferably 0°5111 m or less is obtained.

F Effect of the Invention 1 According to the present invention, it is not necessary to spend a large amount of man-hours to mirror-finish the plate-shaped body, it has the rigidity of a plate-shaped body, the surface has excellent specularity similar to that of synthetic resin, and the thickness is 3-10 with excellent accuracy
It is possible to obtain a substrate for a master optical disk of mm in size very easily, and since the thickness of the substrate can be made thinner than a conventional glass substrate, it is lightweight and easy to handle.

[Example 1] An epoxy resin having a viscosity of 300 cP was applied to the surface of an aluminum plate with a diameter of 200 mm and a thickness of 5111 m, which was coated with an epoxy underfoot resin in advance.
Coat and surface roughness with heavy Hsoog on it
A glass plate of RmaxO, 01 to 0.02 μm is placed with its mirror surface facing the aluminum plate, and due to its own weight,
A thin resin layer was formed on an aluminum plate, and the epoxy resin was heated and cured in this state. Thereafter, by peeling off the glass plate, it was possible to form a 100 μm thick resin thin film on the surface of the aluminum plate, which was a mirror image of the glass. The obtained optical disc master substrate had a thickness of 5.
1±0. O2ll1m, surface roughness Rmaxo, 01~0
．． 02μ..., and was suitable as a substrate for a master of an optical disc.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the process of dropping liquid resin onto a plate-shaped body provided with an undercoat resin layer and placing a mirror plate in the present invention. Figure $2 is a cross-sectional view of the optical disc master substrate obtained by the present invention. 1: Plate body 2: Undercoat resin layer 3: Synthetic resin layer 4: Mirror plate Patent applicant Sumitomo Bakelite Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] In a method for manufacturing a substrate for an optical disk master comprising a plate-shaped body such as a metal plate and a resin thin film formed on the surface of the plate-shaped body, a liquid resin is present on the surface of the plate-shaped body or the mirror surface of a mirror plate, A mirror-finished plate is placed on the plate-shaped object with its mirror surface facing the plate-shaped object, a thin resin layer is formed on the plate-shaped object, and the liquid resin is cured in this state to give the plate-shaped object a mirror surface. 1. A method for manufacturing an optical disc master substrate comprising a plate-like body and a synthetic resin thin film, the method comprising forming a synthetic resin thin film having the following properties.