JPS60230891A - Optical information-recording medium - Google Patents

Abstract

PURPOSE:To enable a coloring matter thin film recording layer to be provided without producing adverse effects on an injection-molded substrate, by using a specified compound as a coloring matter in a coloring matter thin film recording layer of an optical information-recording medium. CONSTITUTION:A compound of the formula, wherein R is subst. or unsubst. alkyl, alkoxyl, aralkyl or alkenyl, X is halogen atom, Y<-> is subst. or unsubst. benzensulfonate, p-toluenesulfonate, methylsulfate, ethylsulfate, benzenecarboxylate, methylcarboxylate or trifuluoromethylcarboxylate, and n is an integer of 0-3, is used as a coloring matter in the coloring matter thin film recording layer of the optical information-recording medium, whereby a recording material can be obtained which is stable to heat, is relatively inexpensive, and can be applied to an injection-molded substrate without any problem. The recording layer can be generally provided by coating according to the usual method. When the recording layer is thinner, sensitivity is better, but reflectance is lower, and accordingly, a preferable thickness of the layer is generally about 10-100nm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium having a dye thin film containing a specific cyanine dye. More specifically, the present invention relates to an optical information recording medium used in a method of directly recording with a laser beam and reproducing information by changing reflected light.

[Prior art]

Conventionally, optical information recording media to which a dye thin film is applied as a recording layer are known (for example, Japanese Patent Laid-Open No. 16948/1983). In other words, in this type of optical memory medium, a metal reflective film is provided between the substrate and the dye thin film recording layer, and a laser beam of a wavelength at which the light absorption rate of the recording layer is at its maximum is focused and irradiated from the recording layer side. It is used to record and reproduce information.

However, optical recording materials using such dyes generally have problems with poor storage stability (heat resistance, light resistance), and easy discoloration.Therefore, the present inventors first used a pyrrole-based cyanine dye. and 1-methyl-2-[7-(1-methyl-6,3-dimethyl-5-]
10-2-indolinylidene) -1,3,5-hebutatrienyl) -3,3-dimethyl-5-no rhoindo 1) It was proposed to use lamperfluorate, but the former has poor heat and light resistance. Although the latter improves storage stability, it requires a strong solvent, so there is a problem that when applied to an injection molded substrate, it adversely affects the substrate.

〔the purpose〕

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a recording material that is stable against heat and has problems with relatively inexpensive injection molded substrates. There is a thing called K.

In order to achieve the above object, the present invention consists in using a compound having a specific structure as a dye in a dye thin film recording layer of an optical information recording medium. That is, the dye of the present invention has the structural formula (wherein R represents a substituted or unsubstituted alkyl group, alkoxy group, aralkyl group, or alkenyl group, X represents...a rogen atom, and ρ represents a substituted or unsubstituted benzene sulfonate. , p-toluenesulfonate, methylsulfate, ethylsulfate, benzenecarboxylate, methylcarboxylate or trifluoromethylcarboxylate, and n is 0
(representing an integer between 6 and 6). Examples of the substituent of the alkyl group for R include groups in which alkyl, hydroxyl, alkoxy, acetyl, carboxyl, halogen, aryl, allyl, hydroxyalkyl, halogenoalkyl, etc. are present on the benzene nucleus. In the dye of the present invention, since the above-mentioned counter ion Y is selected, it can be dissolved in a relatively weak solvent such as alcohol that does not affect the injection molded substrate.

Therefore, according to the present invention, a dye thin film recording layer can be formed without adversely affecting the injection molded substrate.

The optical information recording medium of the present invention basically comprises a substrate and a dye thin film recording layer. If necessary, a subbing layer, a retention layer, etc. can be further provided. It is also possible to form a so-called air sandwich structure in which two recording media are placed facing each other with their recording layers facing each other.

To form the recording layer in the present invention by coating, it is generally necessary to apply the coating according to a conventional method, and the thinner the thickness, the better the sensitivity (although the reflectance also decreases, so the thickness is generally about 10 to 100 nm). Preferably.Also, when forming a recording layer using a dye alone, vapor deposition, sputtering, etc. may be used.In addition to the dye having the above structural formula, such a recording layer may also contain a binder, a metal transition complex, and various plasticizers. A third component such as a stabilizer, a surfactant, an antistatic agent, a lubricant, a flame retardant, a dispersant, etc. can also be included.

Further, as the solvent used for coating, in addition to methanol, ethanol, dichloroethane, etc., other alcohols, halogenated alkyls, ketones, ethers, etc. may be used. There are no particular limitations on the material of the substrate on which such a recording layer is provided (various plastics, glass, etc. can be used).

Information is recorded by focusing laser light with a lens to form minute holes (bits) on the recording layer, and reading is performed by irradiating weak laser light and detecting the difference in reflectance between the bit area and other areas. This can be done using.

〔Example〕

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

A substrate with guide grooves that has been exploded by injection molding acrylic resin is used with the dye shown in the structural formula in the table below or in combination with other components, and 1.2% by weight thereof is dissolved in an appropriate solvent. Spin coat the solution and dry it to a film thickness of 48 nm.
A recording layer was obtained.

A semiconductor laser with a wavelength of 79 D nm was used for the recording medium obtained in this way, and the irradiation surface power was 3.5 mW, the beam diameter was 1.5 μm, and the linear velocity was 1.2 m/sec, Q, 7 M.
A signal in Hz was recorded. When this recording section was irradiated with a 0.3 mW laser beam and the signal was reproduced, the C'/N was 57 dB.
was obtained (IF bandwidth 30 KHz). Also 7
, 3 Vp-p tracking error signals were obtained.

This recording medium was stored in an oven at 100° C., and the rate of discoloration due to heat was examined based on changes in transmittance. The results are summarized in the table below.

Example Color Pigment Melter No Error Error Error Error 57 L 7:3 1.0 56 L 7.4 1.0 58 L 7.6 1.2 56L 7.1 1.0 56 L 7. 2 1.1 L 57 H6,61,2 Example Dye Solvent Dichlore Comparative Example 2 Same as above, 7 Note: In the table, rLJ in the laser section means a semiconductor laser, and rHJ55 L 7.1 0. 8 55 L 7.0 1.1 56 L 7.0 0.7 48 L 4.2 0.9 5OL 2.5 0.9 55 L 7.1 15.6 56 L 6.8 2α4 is He-Ne means laser.

〔effect〕

The recording materials containing the dyes of the invention are thermally stable and can be applied to relatively inexpensive injection molded substrates.

Patent applicant Rico Co., Ltd. Agent: Patent attorney Shiro Tsuchiyamashita

Claims (1)

[Scope of Claims] As a dye on a substrate, a structural formula (wherein R represents a substituted or unsubstituted alkyl group, alkoxy group, aralkyl group, or alkenyl group;
・Represents a rogene atom, p represents substituted or unsubstituted benzenesulfonate, paratoluenesulfonate, methylsulfate, ethylsulfate, benzenecarboxylate, methylcarboxylate or trifluoromethylcarboxylate, and n is 0 to 6 An optical information recording medium comprising a dye thin film recording layer containing a compound (representing an integer of ).