JPS60167142A - Laser recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material having no warpage and waving without receiving the influence of dust by providing a layer contg. specific oxide, nitride or fluoride and a layer contg. antielectrification agent on the surface of the substrate of an information recording medium on which laser light is made incident. CONSTITUTION:A layer consisting of at least one kind selected from the group consisting of a synthetic high polymer having <=0.3% water absorptivity specified by ASTM D570, oxide of Zn, Mg, Al, Si, Zr, Ce, In, Ti, Ge, Ni, Nb, etc., nitride of Zn, Mg, Al, Si, Zr, Ce, In, Ti, Ge, Ni, Nb, etc. and fluoride of Mg, Ca, Ce, etc. and a layer contg. an antielectrification agent are provided on the laser light incident side of a substrate. A laser recording material which is not influenced by dust and is free from warpage and waving is thus obtd. The defect of the recording layer that may arise from the change in properties of the recording layer due to moisture in air is prevented as well. The effect of preventing dust sticking is maintained for a long period of time.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an information recording medium that can be optically recorded and/or read by irradiation with focused laser light. In particular, the present invention relates to a laser recording material on which information can be optically written and/or read by irradiation with a laser beam.

(Prior Art) Conventionally, there is a recording medium that uses a high energy density beam of a laser beam. In such a thermal recording medium, the recording layer has a high optical density and absorbs the irradiated high energy density light beam, causing a local temperature increase.
The light is irradiated by physical or chemical changes7
Information is recorded by changing the optical characteristics of the 'C part.

In such a laser recording material, if dust adheres to the surface on the laser beam incident side, diffuse reflection will occur, which will cause trouble during recording and reading.

In order to prevent this, a thick transparent substrate is used, the distance between the substrate surface and the recording layer is increased, and the focused laser beam is incident from the transparent substrate side to prevent the influence of dust that adheres to the substrate surface by 7'cm. Attempts were made to the Japanese Patent Publication No. Akihiro J-J311 and the Special Publication Akihiro J-J311.
-- Preventing the influence of dust and odor such as Jλ R31 is not sufficient.

(Objective of the Invention) An object of the present invention is to obtain a recording material free of corrugations and ridges that are affected by dust.

In addition, defects in the recording layer caused by deterioration of the recording layer due to moisture in the air can be prevented, the effect of preventing dust from adhering can be maintained, and the substrate surface is less likely to be scratched during handling. There are advantages.

(Structure of the Invention) As a result of research to prevent the influence of dust, the present inventors installed ASTM Dj7 on the laser beam incident side of the substrate.
Synthetic polymer with a water absorption rate of 0.3 cm or less defined by 0, Zn%
Mg%At%Si%Zr5Ce%In%Ti,
Oxides such as Ge, Ni, Nb, etc., Zn%Mg% At%
81% Zr, C41% IntTl, Get Nts
Nitride such as Nb and Mg.

It was discovered that this problem could be solved by providing at least seven selected types (group consisting of fluorides such as CB%CO) and an antistatic agent, and this was the basis of the present invention. If only a surfactant is used, the substrate will deform due to moisture absorption by the surfactant, and the laser beam will always be focused on the surface of the recording layer. It becomes difficult for them to follow suit. Furthermore, the effect of preventing dust adhesion also disappears with long-term use.

By providing the aforementioned synthetic polymer with a water absorption coefficient of 0.3 or less, the oxide of the aforementioned metal, etc., or the fluoride of the aforementioned metal, etc., and an antistatic agent on the laser beam incident side, dust can be reduced. It is possible to obtain a laser recording material that is not affected by interference and is free from wrinkles and waviness. It is also possible to prevent defects in the recording layer caused by deterioration of the recording layer due to moisture in the air.

Furthermore, the effect of preventing dust from adhering can be maintained for a long period of time. The recording material of this invention has the advantage that its surface is less likely to be scratched during handling.

A synthetic polymer with a water absorption rate of 0.3% or less, an oxide of the above-mentioned metals, or a fluoride of the above-mentioned metals, etc., and an antistatic agent are mixed to form one layer, and the laser beam incident side of the recording material is mixed. However, first, a synthetic polymer with a water absorption rate of 0.3% or less, an oxide or nitride of the above-mentioned metals, or a boiling point of the above-mentioned metals should be placed on the recording material Ω laser beam incident side. It is more effective to provide a layer containing a compound and further provide a layer containing an antistatic agent thereon.

When the substrate is on the outside and the laser beam is incident from the substrate side, that is, when it is used in the form of an air sandwich disk like the Tokko Sho J7-3 4L13, or the Tokko Sho! ---
Two substrates t- with the recording layer inside like 3 pieces 31
In the case of the so-called double-sided method, these layers are provided on the outside of the substrate.

When laser light is incident from the recording layer side, these layers are provided on the recording layer.

The present invention will be explained in detail below.

The substrate may be glass, Cerquiasto polymethyl methacrylate, injection molded polymethyl methacrylate, vinyl chloride, vinyl chloride copolymer, polycarbonate, etc.
Optical properties, flatness, processability, handling, stability over time,
Selected based on cost.

The surfaces of these substrates include materials with improved flatness), increased adhesive strength with the recording layer, increased sensitivity due to insulation effects,
It is convenient to apply a rough coating to prevent the recording layer from deteriorating in quality. Examples of the undercoat layer include polymethyl methacrylate, acrylic acid-methacrylic acid copolymer, styrene-maleic anhydride copolymer, polyvinyl alcohol, N
- Methylolacrylamide, styrene sulfonic acid copolymer, styrene-vinyltoluene copolymer, chlorinated polyethylene, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, vinyl chloride copolymer, polyester, polyimide, vinyl acetate-vinyl chloride Various polymers such as copolymers, ethylene-vinyl acetate copolymers, polyethylene, polypropylene, and polycarbonates are used. The film thickness is jdO10/-V θμ J/C,0
, / to 10 μm, and is applied by dissolving or dispersing it in a suitable solvent and applying methods such as coating, tip coating, extrusion coating, and barcode screen printing. If necessary, provide an anti-reflection layer.
A recording layer is provided on top of this.

Materials used as the recording layer include materials used in the technical field, such as Te%Zn%InsSn
%Zr% kt%Cus Metals such as Ge; B l %
Metalloids such as As%sb; semiconductors such as 00%81; alloys or combinations thereof are used. Compounds of these metals or semimetals such as sulfides, oxides, borides, silicides, carbides, and nitrides, and mixtures of these compounds and metals can also be used in the recording layer.

To form a recording layer using these materials, vapor deposition, sputtering, ion blating, etc.
It is provided with a thickness of 0A.

The present invention can be applied to a single-plate optical information medium as well as a sandwich-type or air-sandwich-type optical information recording medium, and in particular, an air-sandwich-type recording medium is one in which two recording sheets made as described above are used. The elements are pasted together with the recording layer inside through a spacer (the recording layer may be provided on the split substrate or only on one side), and the spacer is attached to the intermediate layer. It may be joined on top of the

When laser light is input from the opposite side of the board with a single board type,
The above-mentioned synthetic polymer having a water absorption of 0.7% or less, the above-mentioned specific oxide, or the above-mentioned specific fluoride, and an antistatic agent are provided on the recording layer. In the case of the air sand inch type, it is provided on the surface of the substrate opposite to the recording jtI.

The water absorption rate of the synthetic polymer is measured by the method specified in ASTM Dj7θ. In other words, the diameter! 0. Iwrs (2 inches) thick! , -2 wrll/I inch) of a synthetic polymer disk was immersed in water at 23° C. for 4/1 hour, and then the water absorption lid was expressed in weight percent.

Examples of polymers with a water absorption rate of 0.7fi or less include polytetrafluoroethylene, polyethylene, polyvinyl fluoride, polypropylene, polyvinyl chloride, vinyl chloride-acetate copolymer, polystyrene,
vinylidene chloride-vinyl chloride copolymer,
Examples include ethylene-tetrafluoroethylene copolymer and vinyl nitrile rubber.

/ Among these polymers, preferred ones have water absorption rate o,
orqb or less, among which polytetrafluoroethylene, ethylene-tetraph-βa ethylene copolymer and vinylidene chloride-vinyl chloride copolymer are the best.

The film thickness of these polymers is preferably 7 to 10μ, and can be dissolved or dispersed in a suitable solvent and coated with spin codes, dip coats, extrusion coats, barcode screen printing, etc. It is applied by the following coating method.

When using the above-mentioned specific oxides and fluorides for polymer coatings with a water absorption coefficient of 0.3 or more, the film thickness is generally determined by resistance heating evaporation, sputtering, ion blating C, V,
Provided by DK.

Among these specific oxides, nitrides and fluorides, the preferred monomers S i O'2, Si0% 5iaN4, A
z2oa1MgF2, Ni01Ti02 and MgO, most preferably 5102.813N4 and MgF
It is 2.

The antistatic agent is a polymer having a water absorption rate θ of 3 or less as described above,
Coated over specific oxide or fluoride layers. Also, water absorption rate is 0. When using a polymer under J-Chili, you can either knead it into the polymer or dissolve it in an appropriate solvent and add it to the polymer solution and apply it to the substrate. is used. Specifically, the "Surfactant Handbook" published by Sangyo Tosho Co., Ltd. Hundred~μ!
The one listed on the page is used.

When applying to the surface of the polymer layer, the amount used is j ~ j 00
m9/1% 2 preferably jO~200m97m
It is 2. When it is contained in the polymer layer, i.

O~J 000mg/m2, preferred amount SOθ~λo
ootng7m”.

The cationic type that is most effective when applied is Ct 7 Ha 5cONH-cH2Nic2)1
5) Primary amine salts such as 2Hct, μ-class ammonium compounds, imidacillin type such as HalR: C4-3o hydrocarbon group, and anionic type R803Na (11: C1,2
Alkyl sulfonic acid salts such as alkyl groups of 2), alkylbenzenesulfonic acids such as kyl groups), nonionic R-0-1cH2c:R20) nHI R:C
RC
)L2CUO(C)12CI-120) nH(R:
Ethylene oxide adducts of fatty acids such as C, 2 to 8 hydrocarbon groups, 11: integers of s to 30), lR: alkyl groups of ct to 2o, n and m are integers of 1 to 30) Amide ethylene oxide adduct, ethylenediamine ethylene oxide adduct and R
NHIGH2C) i20) nHI R: an alkyl group of C1 to 20, an integer of nV11 to JO), a betaine type such as an ethylene oxide-added hydrocarbon group of an aliphatic amine, and hydroxyethylimidanline sulfate. When kneaded into a polymer or dissolved in a solvent and added to a polymer solution, the most effective are cyclohekifluamine lysyl phosphate, tributylamine phosphate, didodecyl dipropylammonium bromide, Cationic salts such as amine salts and ammonium salts such as octylcyclohexyldimesulfammonium tetralide, lead salts of para/mono-tertiary aminophenol, anionic salts such as pentapropyl triphosphate, ethylenediamine ethylene oxide adducts, polyethylene glycol,
There are nonionic surfactants such as butyl ester of adipic acid, and amphoteric surfactants such as imidacillin copper salt. Further, it is particularly effective to use a mixture of an anionic type and a nonionic type, or a cationic type and a nonionic type.

Next, the present invention will be explained by way of examples. Note that the dust MW and area defect rate in the present invention were measured by the following method.

Dust adhesion level: Based on Procter &Giampre's dust chamber method. That is, soot is made by impregnating paper with toluene and burning it, and circulating it in a sealed container with a relative humidity of 1j. After 4c hours, the degree of soot adhesion is observed with the naked eye, and using a standard diagram, the index / -10 is determined. The M'F value was determined on a 10-level scale.

A value of 7 or higher means that there is almost no dust adhesion.

Area defect rate: An air sandwich type disk-shaped laser recording material having a diameter of 301 telK was left in a room with a humidity of 6j and a temperature of j0C for j days, and then the following measurements were carried out. The laser recording material was rotated at fj00 rpm, and the distance from the inner diameter of 10916M to l and r was approximately //
The reflected light was measured by scanning with a laser beam focused to have a diameter of , &μ. If there is dust adhering to the substrate surface, fc, or if there is a defect in the recording layer, it will be detected as a change in the reflection of the laser beam.This area defect rate measurement device uses polystyrene colloid particles with a known particle size. Calibration was performed in advance using a standard sample coated with laser output level o, o
ri■, θ, 33■, l.

ao■ and 3. It is designed so that defects of 0.3μ or more, Iμ or more, 3μ or more, and 10μ or more are detected at θO■, respectively. The total number of defective planes detected at each of these laser output levels was divided by the measured area, and this was taken as the area defect rate.

,/ The present invention will be explained below with reference to Examples.

Example 1 A methyl ethyl ketone solution of polyvinylidene chloride (water absorption rate o, oi% or less) was applied to the surface of a cell-cast acrylic plate having a thickness of /, ja and dried to a dry film thickness of 10 μm. Furthermore, on this layer of polyvinylidene chloride, an antistatic agent was dissolved in a mixed solvent of methanol/water and dried so that the coating amount after drying was 7 m. After punching out a donut shape with an inner diameter of JjrLtM, the part on the back side where the recording layer is to be provided is shielded and glow discharge treatment is performed concentrically around the outer periphery and the center.Then, the part that has been subjected to glow discharge treatment is shielded and the same vacuum is applied. In the system, In is added in an amount equivalent to the thickness of the SOA, and Ga is added in an amount equivalent to the thickness of the SOA.
A recording layer was formed by codepositing an amount equivalent to 200 Se. The two substrates carrying the recording layers prepared in this manner are placed with the recording layer J- on the inside, and have an outer diameter of 3θjiff and an inner diameter of J.
An air-sand inch type laser recording material was obtained by laminating OOIn and a ring-shaped spacer with an outer diameter of 'fiOH1 and an inner diameter of ssB with an ultraviolet curable adhesive. Furthermore, the above-mentioned polyvinylidene chloride and the above-mentioned antistatic agent were applied to the inside of the periphery, that is, on the side surfaces of this recording material, respectively. θm
The laser recording material of the present invention was obtained by coating and drying to give a coating density of 9/m 2 .

Example 2 Example! The present invention was prepared in the same manner as in Example 1, except that polyvinylidene chloride glue DK, ethylene-tetrafluoroethylene copolymer was used, and sodium octylbenzenesulfonate was used as an antistatic agent at ioo~/m2. information recording medium was obtained.

Example 3 In Example 1, CaHl 7-0- (CH2CI-120) l O was used as an antistatic agent.
A recording material of the present invention was obtained by processing in the same manner as in Example 1, except that Ht-/zo mg7 m2 was used.

Example 4 A laser recording material of the present invention was obtained by processing in the same manner as in Example 1, except that polyvinylidene chloride K Si 02 was sputtered to a thickness of 700 mm. .

Comparative example! Example 1 except that the antistatic agent layer was not used in Example 1.
A recording material having only polyvinylidene chloride coated on the surface was obtained by processing in the same manner as above.

Comparative Example 2 A recording material was obtained in which polyvinylidene chloride was used and the same treatment as in Example 1 was carried out except that the antistatic agent was coated on the surface.

With respect to these recording materials, the degree of dust adhesion and area defect rate were measured as described above, and the deformation of the disks after being left in an atmosphere of ao'c, atatheta, and RH for a week was observed.

The results are shown in Table 7.

Claims (1)

[Scope of Claims] An information recording medium having a recording layer on which information can be written and/or read by a laser, and the surface of the substrate onto which the laser light is incident has a water absorption rate of 0. 3% or less of synthetic polymers, Zn, Mg,
ht, S1% Zr%C. In, Ti, Ge%Ni, Nb, etc. oxides, Z
n 5Mg5 At% Sis Zr%co, In%
Nitride such as Ti%Ge%Ni%Nb and Mg, c,. An information recording material characterized by containing at least seven selected from the group consisting of fluorides such as C, and an antistatic agent.