JPS629548A - optical information recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium having an air sand inch structure in which information can be recorded and reproduced using a high-energy beam such as a laser beam.

[Prior art]

Conventionally, metal, semimetal, and nonmetal vapor-deposited films or organic dye films have been known as recording layers of optical information recording media. However, these recording layers have a problem in that they are affected by scratches, outside air, light, etc., resulting in decreased storage stability. Various proposals have thus far been made to solve this problem. An example of this is an air sandwich structure in which the recording layer is sealed between substrates, but this method cannot completely prevent moisture permeation, and if the recording layer is rapidly cooled from a high temperature state, dew condensation may occur on the recording surface. This may cause defects. Another example is a method of providing a protective layer such as 8i0, but this complicates the manufacturing process and causes the same drawbacks as above if pinholes or the like occur.

〔the purpose〕

The present invention has been made in view of the above problems, and its purpose is to improve the reliability of optical information recording media.

〔composition〕

When a recording medium with an air sandwich structure is exposed to high temperature and high humidity, water vapor enters the sealed space through the substrate, and when it is rapidly cooled, the sealed space becomes supersaturated, causing dew condensation on the inner walls and recording. Severely affects membranes. Therefore, the present inventor conducted various studies on preventing dew condensation, and found that if a hydrophilic resin is present on the inner wall of the sealed space of a recording medium having an air sandwich structure, that part will not act as a nucleus for condensation, and other parts will The present inventors have discovered that supersaturated water vapor can be absorbed by a hydrophilic resin without condensing, leading to the present invention.

That is, the optical information recording medium of the present invention has a structure in which at least one of two disk-shaped substrates has a recording layer on one side and is sealed with a spacer in between so that the recording layer is on the inside. A part of the sealed inner wall is made of hydrophilic resin.

Next, a configuration example of an optical information recording medium according to the present invention will be explained with reference to the drawings.

As shown in FIG. 1, in one embodiment of the present invention, a recording layer 2 is provided on one substrate 1, and a hydrophilic resin layer 3 is provided on the other substrate 1.

Although the thickness of the recording layer varies depending on the type of recording material, it is generally appropriate to have a thickness of 10 to 300 nm. Moreover, the thickness of the hydrophilic resin layer is suitably 1 to 50 μm. These substrates 1.1
are arranged concentrically with the recording layer 2 and hydrophilic resin layer 3 inside using an inner spacer 4 and an outer spacer 5, and are sealed so that a space 6 is formed between the mutually facing surfaces of each substrate. . Note that a fitting hole 7 is provided in the center of the substrate 1.1. As the substrate, plastic, glass, etc. that are transparent to high-energy beams such as lasers can be used. Further, the substrate may be provided with a guide groove, an undercoat layer, etc. The recording layer is not limited to any particular material and can be any material containing recording materials commonly used in optical information recording media. Typical examples of recording materials include metal materials such as Te5Bi and Be, and organic dyes such as methine dyes. Further, examples of the hydrophilic resin material used for the hydrophilic resin layer include polyvinyl alcohol, polypeptide resin, casein, gelatin, polyacrylamide resin, polyethylene glycol, and cellulose resin.

In another embodiment of the invention shown in FIG. 2 two substrates 1.1
A recording layer 2 is provided thereon, and a hydrophilic resin layer 3 is provided on the side surfaces of the inner circumferential spacer 4 and the outer circumferential spacer 5.

In another embodiment of the invention shown in FIG. 3, two substrates 1. ．．
A hydrophilic resin layer 3 is provided on the recording layer 1 in parallel with the recording layer 2 .

〔Example〕

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 Two polymethyl methacrylate substrates with a diameter of 2005 m and a thickness of 1 m were used, one of which had a thickness of 30 nm.
A recording layer is provided by depositing a Te film of A recording medium was produced.

This recording medium was left in an environment of 40° C. and 90% for one day, and then suddenly placed in an environment of 5° C. for 30 minutes. This test is 5
The periphery was repeated, but no defects occurred.

Comparative Example 1 A recording medium was produced and tested in the same manner as in Example 1, except that the polyvinyl alcohol resin layer was not provided on one of the substrates in Example 1. When the number of defects was 3, which was the initial value, doubled.

Example 2 After providing a guide groove made of a photocurable resin on a polymethyl methacrylate substrate having a diameter of 200mm and a thickness of 1cm, 1.
3.3-)limethylindotricarbonine perchlorate (1,3,3-)diethyl-2-C7-(1,
3,3-)diethyl-2-indolinylidenebutatrienyl)]-indolium verchlorate) and bis-(4-diethylaminobenzyldithio)nickel0.
A 2-dichloroethane solution was applied to obtain a recording layer with a thickness of 60 nm. Furthermore, after providing a hydrophilic resin layer (7 μm thick) of polyethylene glycol with a degree of polymerization of 5000 on the inner unrecorded area of this recording medium, the structure shown in FIG. A recording medium was produced.

A test similar to that in Example 1 was conducted, but no defects were found.

Comparative Example 2 A recording medium was produced in the same manner as in Example 2 except that the polyethylene glycol resin layer was not provided in Example 2, and a test was conducted.
doubled.

〔effect〕

As described above, by providing the hydrophilic resin layer in the closed space of the air sandwich structure, it is possible to obtain an optical information recording medium that is resistant to rapid environmental changes.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing an example of the structure of an optical information recording medium according to the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording layer, 3... Hydrophilic resin layer, 4... Inner spacer, 5... Outer spacer, 6...
... Space, 7... Fitting hole. Patent applicant Rico Co., Ltd. - 2 others

Claims (1)

[Claims] Each substrate has a recording layer on one side of at least one of the two disc-shaped substrates, and the structure is such that each substrate is sealed via a spacer so that the recording layer is on the inside, and a part of the sealed inner wall is hydrophilic. An optical information recording medium characterized by being made of a synthetic resin.