JPH0679387B2 - Information recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information recording medium having an air soldering structure.

[Prior Art] Easy handling as a material for optical disk memory substrates,
Recently, plastic materials have been mainly used because of their light weight. Among them, polymethylmethacrylate or polycarbonate, which has excellent optical properties, is mostly used. When a so-called Air-San Germany-made disc as shown in FIG. 1 is manufactured using these substrates, the material of the spacer has conventionally been a coefficient of thermal expansion,
The same material as the substrate was used so that the moisture absorption deformation rate and the like would match the substrate. However, since polymethylmethacrylate and polycarbonate have not so good adhesiveness with the sealing adhesive, it is necessary to perform surface treatment such as roughening and structural reinforcement as shown in FIG. .

〔Purpose〕

The present invention has been made in view of the above situation, and an object thereof is to improve the sealing reliability of an air-sun German type sealing structure and prevent deformation of a substrate.

〔Constitution〕

The present inventor has noticed that many of the resins as the substrate material have good adhesiveness with the sealing adhesive, and it is expected that the process can be simplified by replacing the spacers with such a resin. As a result of studying various resin materials, acrylonitrile-butadiene-styrene resin (ABS resin) is used as a spacer material with small deformation of the disk due to the difference in expansion coefficient between the spacer material and the substrate material and good adhesiveness with the adhesive. , Acrylonitrile-styrene resin (AS resin), styrene-butadiene resin (SB resin) and styrene resin were found, and the present invention was completed.

Hereinafter, a configuration example of the information recording medium of the present invention will be described with reference to the drawings.

The disk-shaped substrates 1, 1 are made of, for example, a transparent plastic plate and have a fitting hole 2 in the center thereof. These boards 1,1
The recording layer 3 is formed on one surface of one side. Inner spacers 4 made of these materials according to the invention on these substrates 1, 1
And an information recording medium that is concentrically arranged with the recording layer 3 inside through the outer spacer 5 and is bonded with an adhesive 7 in a state where a space 6 is formed between mutually facing surfaces of the respective substrates. 8 is configured.

As the recording layer 3, any material known as a recording material for a recording medium can be used and is not limited to a specific material. Typical examples thereof are thin metal films such as Te and Al, polymethine dyes (eg cyanine dyes, merocyanine dyes), phthalocyanine dyes, tetrahydrocholine dyes, thioxazine dyes, triphenothiazine dyes, phenanthrene dyes, anthraquinone. Dyes, xanthene dyes, triphenylmethane dyes, croconium dyes,
Examples thereof include organic dye thin films such as azulene-based dyes, pyrylium-based dyes, squarylium-based dyes, and naphthoquinone-based dyes. The recording layer may contain a stabilizer (for example, a metal complex compound), a binder, an antioxidant, a flame retardant, a surfactant and the like. The recording layer can be formed by a conventional method such as vapor deposition or coating.

As the substrate, it is preferable to use an inexpensive and lightweight plastic substrate. Particularly, polymethylmethacrylate (PMMA) and polycarbonate are preferable in terms of optical characteristics. The substrate may be provided with a pregroove layer by, for example, a photopolymer method.

〔Example〕

The present invention is further described below with reference to Examples along with Comparative Examples, but the present invention is not limited to these Examples.

Using a combination of the substrate material and the spacer material shown in the table below, a disk having an air sun-deer structure having a diameter of 20 cm as shown in FIG. 1 was manufactured. A pregroove layer was formed on the substrate by a photopolymer method, and then a dye recording layer was formed by a spin coating method. An ultraviolet curing adhesive was used to assemble the sealing structure.

The disk thus prepared was left in an environment of 50 ° C and 90% for about 500 hours, then the inclination of the disk surface in the disk radial direction was measured and compared with the initial value, and the results are shown in the table below. Show.

[Effect] Since the spacer made of the material of the present invention has good adhesiveness with the sealing adhesive, it has an effect of not requiring surface treatment such as roughening and reducing the deformation of the substrate.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of an information recording medium according to the present invention, and FIG. 2 is a partial sectional view showing the structure of a conventional spacer. 1 ... Substrate, 2 ... Fitting hole, 3 ... Recording layer, 4 ... Inner spacer, 5 ... Outer spacer, 6 ... Space, 7 ... Adhesive, 8 ... Information recording medium.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Umehara 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (56) References: 61-90030 (JP, U)

Claims (1)

[Claims] 1. At least one of two disk-shaped substrates
An information recording medium having an air soldering structure in which one substrate having a recording layer on one surface thereof is laminated so that the recording layer is on the inside via an inner peripheral spacer and an outer peripheral spacer which are concentrically arranged. In the above, the spacer is made of either acrylonitrile-butadiene-styrene resin, acrylonitrile-styrene resin, styrene-butadiene resin or styrene resin,
Information recording medium.