JPH035746A - Novel recording material - Google Patents

Abstract

PURPOSE:To improve the preservable stability of the above material and to allow the sufficient use thereof even under severe conditions by bringing an org. solvent soluble silver compd. and reducing agent into reaction in the presence of the silver or metal developing nucleus nobler than the silver. CONSTITUTION:The internal org. solvent soluble silver compd. is diffused to the surface to form a thin film layer of the metal having reflectivity by making use of the oxidation-reduction reaction effected by the org. solvent soluble silver comopd. and the reducing agent when heated. Namely, the metal silver- contg. layer formed by bringing the org. solvent soluble silver compd. and the reducing agent into reaction in the presence of the silver or the metal developing nucleus nobler than the silver is so formed as to have 10 to 90% reflectivity. The material which is strong to preservation even at and under a high temp. and high humidity over a long period of time and is not cracked even under the use conditions severe in terms of bending, etc., is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a new digital recording material suitable for writing and reading mainly using laser light.

(Prior Art) In recent years, laser-related technology has made remarkable progress, information has been digitized, and various new optical recording materials necessary for this have been proposed.

A typical digital recording material is an optical disc. Separately, high-density, portable optical card materials have been proposed for convenient handling. As an example of this, JP-A-59-5021
The optical card developed by Drexler, which is described in Japanese Patent Application Laid-Open No. 58-188346 and others, is famous.

Furthermore, various companies are developing optical card materials using materials similar to those used for optical disks. On the other hand, optical tape has been proposed as a material that is more compact than optical disks and can record a large amount of information.

Although several systems and materials have been proposed in this way, the characteristics necessary for recording materials, such as writing sensitivity, storage stability of recording materials, recording density, and error rate, are still insufficient.

For example, Drexler has proposed that a reflective film be formed on the surface of a wet silver salt photographic material through special treatment, and used in optical cards. Due to the use of gelatin,
Problems have been pointed out, such as poor storage under long-term conditions of high temperature and humidity. Furthermore, since optical tapes and optical cards are expected to be used under harsher conditions than optical disks, such as in terms of bending, existing metal thin film materials may crack, so new materials have been sought after. .

(Problem B to be Solved by the Invention) The present invention provides an optical recording material that has excellent storage stability under high temperature and high humidity conditions and can be satisfactorily used as an optical recording material even under severe usage conditions such as bending. It is.

Furthermore, the present invention attempts to provide a low-cost recording material that can be continuously produced.

That is, the recording material of the present invention can be produced using very common industrial production methods such as continuous coating with a roll coater and continuous heating with a hot roll, thereby making it possible to reduce the cost of the recording material. .

(Means for Solving the Problems) The present invention is a completely new optical recording material that utilizes the fact that an organic solvent-soluble silver compound and a reducing agent undergo a redox reaction when heated. That is, in the present invention, in the reaction between an organic solvent-soluble silver compound and a reducing agent, silver or a metal development nucleus nobler than silver acts as a catalyst nucleus to form a layer of metallic silver.

As described above, as a result of various studies, the present inventors discovered that it is possible to form a reflective metal thin film layer on the surface by diffusing the internal organic solvent-soluble silver compound onto the surface, which is completely new. be.

Such a novel optical recording material of the present invention can be defined as follows. That is, it is an optical recording material in which a metallic silver-containing layer formed by reacting an organic solvent-soluble silver compound and a reducing agent in the presence of silver or a metal development nucleus nobler than silver has a reflectance of 10 to 90%. .

In this case, whether or not there is a clear boundary between the reflective metallic silver-containing layer and the silver-supplying layer in this optical recording material is not important for the optical recording material. However, in order to improve the recording density as an optical recording material, metallic silver must be present uniformly dispersed as a dispersion that is infinitesimal than at least 2 to 3 μm, or
It is preferable to use a metallic silver layer that can be handled as a uniform continuous film on the order of μm.

Note that the reflectance value is expressed as the intensity ratio of light reflected at a specular reflection angle (75°) to light incident on the optical recording material at an angle of 751°. The measurement wavelength is 750~
Light around 850 nm is used.

The thickness of the recording layer itself, which is a combination of the metallic silver-containing layer and the silver supply layer of this optical recording material, is such that as long as a difference in reflectance can be obtained, the thinner the recording layer, the higher the recording density and the lower the cost. Although it is preferable, it is usually set to about 1 to 25 μm.

Also, the larger the reflectance value, the easier it is to construct a detection system, but conversely, if the reflectance is high, the laser light cannot be effectively absorbed (so in practice, it is
%, preferably about 25 to 65%.

In the optical recording material of the present invention, pits are formed in the metal silver-containing layer by a laser beam such as a semiconductor laser or a He-Ne laser, and information is recorded by changing the reflectance.

The optical recording material of the present invention is prepared by uniformly dissolving an organic solvent-soluble silver compound and a reducing agent, uniformly coating the solution on a suitable support, and then drying the solution.

As the organic solvent-soluble silver compound, those soluble in organic solvents are selected from aliphatic carboxylic acid silver salts and silver metal chelate compounds. For example, as a preferable aliphatic carboxylic acid group, a fluorine-containing aliphatic carboxylic acid group is used, and as a silver metal chelate compound, for example, a fluorine-containing chelating agent typified by fluorine-containing β-diketones is used. is commonly used. Particularly preferred compounds include silver trifluoroacetate, silver hebutafluorobutyrate, silver perfluoro octanoate, silver trifluoromethanesulfonate, silver furoyl trifluoroacetonate, silver hexafluoroacetylacetonate, silver hebutafluorobutyrate. Examples include butanoyl pivanoyl methanate, silver pivaloyl trifluoroacetonate, silver pivaloyl trifluoroacetylacetonate, silver furoyl trifluoroacetonate, and the like.

The organic solvent soluble silver compound should be used at a ratio of 1 m to 1 m of commonly used organic solvents such as alcohols, ketones, ethers, nitriles, halogens, aliphatic, aromatic, etc.
It is preferable to use one that melts more than g.

As a reducing agent for this organic solvent soluble silver compound,
Any material may be used as long as it can reduce the organic solvent-soluble silver compound. Reducing agents include inhibiting phenols in which a sterically bulky group is bound to the carbon adjacent to the carbon to which the hydroxyl group is bound, sterically inhibiting the hydroxyl group, such as 2,6-di-t-butyl. -4-methylphenol, 2.2″methylenebis-(4-methyl-6-
t-butylphenol), 2.2°-methylenebis-
(4-ethyl-6-t-butylphenol"), 2.
4.4-Trimethylpentylbis(2-hydroxy-
3,5-dimethylphenyl)methane, 2,5-di-t
-butyl-4-methoxyphenol, 2-t-butyl-
6-(3-t-butyl-2-hydroxy-5-methylhensyl)-4-methylphenylacrylate, 4.4'-butylidene-bis-(3-methyl-6-t-butylphenol), triethylene glycol-bis (3-(3
-t-butyl-5-methyl-4-hydroxyphenyl)propionate), 1,6-hexanethiol bis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate L2.4- Bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t
-butylanilino L1.3.5-) riazine, pentaerythrityl-tetrakis-[3-(3,5-di-t-
butyl-4-hydroxyphenyl)propionate),
2.2-thio-diethylenebis(3-(3,5-di-t)
-butyl-4-hydroxyphenyl)propionate]
, octadecyl-3-(3,5 di, t-butyl, 4-hydroxyphenyl) propionate, 2,2-thiobis(4-methyl-6-t-butylphenol), N, N
'-hexamethylenebis(3,5-di(-butyl-4
-hydroxy-hydrocinnamamide), 3,5-di-1-butyl-4-hydroxy-penzylphosphoonerethyl ester, 1,3,5-trimethyl-2,
4,6-Tris(3,5-di-t-phthyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4-hydroxybenzylethyl)calcium, tris-(3,5 -di-1-butyl-4-hydroxyhensyl)-isocyanurate, N,N'-bis(
Examples include 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl)hydrazine. In addition, reducing agents for silver salts such as hydroquinone, 25-dimethylhydroquinone, chlorohydroquinone, p-aminophenol, methylhydronaphthalene, phenidone, methyl gallate, P-phenyldenol, bisphenol A, 2,4-dihydroxybenzoin, etc. An acid, ρ-methoxyphenol, can also be used. The amount of reducing agent varies depending on the type of reducing agent, etc., but in terms of -ta,
Approximately 0.01 mol to 1 mol of organic solvent soluble silver compound
About 10 moles, preferably about 0.1 moles to about 3 moles.

The organic solvent-soluble silver compound and the reducing agent are previously dissolved in a solvent together with the polymer compound to prepare a uniform coating solution. Examples of solvents include alcohol solvents such as methanol, ethanol, and isopropyl alcohol; ketone solvents such as 2-butanone and acetone; ester solvents such as ethyl acetate; and aromatic hydrocarbon solvents such as toluene, xylene, and cyclohexane. Are you there? 8 mediums can be mentioned.

Here, the selection of a polymer compound as a binder is not only important in creating a stable coating solution, but also has a large effect on the storage stability of the optical recording material obtained after coating, drying, and heat development. It is important to give. In particular, hydrophilic binders such as gelatin, polyvinyl alcohol, etc. should be avoided in order to provide more favorable stability under high humidity storage conditions.

In the present invention, preferred binders are appropriately selected from a wide range of hydrophobic organic polymer compounds such as polymethyl methacrylate, polyvinyl formal, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, cellulose acetate, and polystyrene. I can do it.

The hydrophobic binder is in a weight ratio of about 10:1 to about 1:1 O to the organic solvent soluble silver compound.

The reflective metallic luster layer of the present invention is manufactured as follows. That is, metal development nuclei are formed on a layer containing an organic solvent-soluble silver compound, a reducing agent, etc. (optical recording material composition N) coated in advance, and further under suitable heating conditions, for example, at a temperature of at least 70°C. When heated for a few seconds to a few minutes,
A reflective metallic silver-containing layer is formed on the surface layer. Usually, from the viewpoint of heat resistance of the support and ease of handling during manufacturing, it is
Heat at a heating temperature below 0'C. In order to form this reflective metal silver-containing layer, metal development nuclei that act catalytically are essential.

The metal development nucleus is silver or a metal species nobler than silver. Metals more noble than silver include palladium, platinum, gold,
Examples include rhodium, ruthenium, thallium, and mercury. These metal nuclei may be a single metal species, or may be a composite type or a sulfide such as silver sulfide.

The method for forming metal development nuclei on the surface of the optical recording material composition includes a method in which the metal development nuclei are dispersed in a solvent containing a suitable binder and coated on the surface of the optical recording material composition, or vapor deposition. It is also possible to form metal catalyst nuclei on the surface under gas phase conditions. Alternatively, metal development nuclei made of the metal species itself may be formed on the surface by covering the surface with a strong reducing agent or by exposing the surface to a reducing gas such as hydrogen gas for a short time.

For example, typical manufacturing methods include a method in which the surface layer is sequentially immersed in an aqueous solution of stannous chloride and an aqueous solution of palladium chloride, and a metal nucleus is applied by electroless plating in which the metal nucleus of palladium is applied to the surface layer; Examples include a method of vacuum-depositing metals such as platinum, gold, metal, and palladium onto the surface. Further, a compound that forms silver sulfide nuclei, such as sodium sulfide, may be disposed on the surface layer. Alternatively, silver metal development nuclei may be provided on the surface by exposing the surface to a reducing gas such as hydrogen gas for a short time.

When an optical recording material composition layer having such a surface layer is heated under appropriate heating conditions, for example, at a temperature of at least 70°C for several seconds to several minutes, a reflective metallic silver-containing layer can be formed on the surface. can. Appropriate heating conditions are preferably 90 to 200°C and about 1 to 100 seconds.

The heating conditions must be controlled to optimal conditions to satisfy the structure of the present invention. In particular, excessive development tends to cause the reflective metallic silver-containing layer to become non-uniform, so care must be taken.

The optical recording material of the present invention can contain various additive components to improve the intended performance of the material. For example, it is possible to introduce a compound that controls the size of silver particles in the metallic silver-containing layer. I can do it. Examples include toning agents such as phthalazinone used in dry silver salt photosensitive materials. Further, an anti-fogging agent, a sensitizer, etc. can be added as necessary.

Furthermore, in the present invention, it is possible to incorporate photosensitive silver halide into the optical recording material composition, and by such combination, preformat processing can be facilitated by performing pattern exposure through a mask in advance during manufacturing. It was also found that it can be done. Such a change in composition can be achieved by applying a halogen ion source to a part of the N-containing solvent-soluble silver compound to change part of the Ri8-solvent-soluble silver compound into photosensitive silver halide in advance, or by separately preparing a silver halide. There is a method of dispersing previously prepared silver halide microcrystals into an optical recording material composition.

The optical recording material of the present invention is provided with a transparent protective layer for the purpose of protecting the recording layer. This protective layer is selected from highly transparent organic polymer compounds such as polycarbonate, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, and polyethylene terephthalate.

Further, the back surface of the optical recording material layer may consist only of a hese film coated with the optical recording layer, or may further include a reinforcing layer against bending, etc. on the back surface. Further, the surface of the transparent protective layer is usually treated to make it less likely to be scratched.

The optical recording material of the present invention is generally card-shaped, but may be disc-shaped or tape-shaped.

The optical recording material of the present invention can be recorded using various laser light sources having appropriate power, typical examples of which are He-Ne laser and semiconductor laser. For example, ], using a semiconductor laser of about OmW,
Writing can be performed at a speed of several tens of cm/sec with a beam diameter of 2 to 3 μm.

The optical recording material of the present invention can be used as a so-called write-once type recording material, and the user can write on it as needed, and once written cannot be erased, it can be used in applications where evidence is required. can also be used.

You can also write information in advance and use it as a read-only R.
It can also be used as an OM card.

EXAMPLES Below, Examples will be described to explain the present invention in more detail, but the present invention is not limited thereto.

Example 1 A solution consisting of the following components was prepared.

Silver trifluoroacetate 20g22-methylenebis(4-ethyl-6-t-butylphenol)
9g 2-butanone
200g toluene
60g polycarbonate
20 g of this solution was homogenized by stirring for about 1 hour and then passed through a filter with an average pore size of 1.5 μm.

This solution was applied after drying with a small applicator to 6μ
Select a slit so that
,iMi! It was dried under conditions of 50% RH (the obtained sample is referred to as sample N091).

Next, on the sheet of sample No. 1, metal development nuclei, that is, palladium nuclei, were formed on the surface using a catalyst nucleation method for electroless coating manufactured by Nippon Sailing Co., Ltd. After being immersed in the following aqueous solutions for 10 seconds each, the sample was washed with water and air-dried (sample No. 012).

(Water in water) Activator Neo Gant 834 40- (Product name manufactured by Nippon Sailing Co., Ltd.) Trace distilled water 956d Sodium hydroxide g (Aqueous solution 2) Reducer Neo Gant WA 5ml ((Product name manufactured by Nippon Sailing Co., Ltd.) Boric acid 5g distilled water
950 - Each sample obtained was heated at 150°C for 60 seconds.

Sample No. 61 turned reddish-brown, whereas sample No. 62 had roots deposited on the surface layer and a glossy layer. The reflectance was 8.5% for N001, while it was 50.5% for NO62.

Next, a semiconductor laser beam having an emission wavelength of 830 nm (beam diameter 3 μm, emission power 10
A writing test was performed using When pulse oscillation was performed at a scanning speed of 40 co+/sec, pits of approximately 3 μm were formed.

Example 2 A solution consisting of the following components was prepared.

Silver trifluoroacetate 20 g 26-sheet t-phthyl-4-methylphenol g 2-butanone 200 g Toluene 60 g Polyvinyl butyral 18 g Thereafter, an optical recording material was prepared in exactly the same manner as in Example 1. Heating conditions are 140°C130
When measured in seconds, the reflectance was 42%.

Example 3 An optical recording material was prepared with the same composition as in Example 2. However, a method different from that in Example 2 was used for metal development nuclei. A method was used in which after a solution was applied to the support and dried, reducing hydrogen gas was brought into contact with the surface to reduce silver trifluoroacetate on the surface and form silver development nuclei on the surface.

The heating conditions were 150° C. and 80 seconds, and the reflectance of the obtained material was 50%.

Example 4 Consists of the following ingredients? 8? I created a.

CJ'vCOOAg 20
g Polyvinyl butyral 18g2-t
-butyl-8-(3-t-butyl-2-hydroxy-5
methylbenzyl)-4-methylphenylacrylate

8 g isopropyl alcohol 18
5g Cyclohexane 55g Sodium Bromide 0.3g Cobalt Iodide 0.3g This solution, after being homogenized by stirring for approximately 2 hours, has an average pore size of 1.5μ.
passed through a filter of m.

Thereafter, it was coated and dried under the same conditions as in Example 1.

However, the film thickness after drying is 111℃m.
Dry under red safety light. Palladium was adsorbed onto the surface of this sensitive material in the same manner as in Example 1. Thereafter, when heated at 150°C for 10 seconds using a block heater, silver was deposited on the surface, forming a metallic luster layer. The reflectance was 35%.

In addition, when this material is brought into close contact with a photomask, exposed from the photomask side with a mercury lamp, and then heated with a block heater at 150°C for 25 seconds, silver will precipitate on the surface of the unexposed areas, and the silver will become reflective. was formed. The reflectance of the exposed area was 9.7%, and the reflectance of the unexposed area was 38%.

Example 5 A solution consisting of the following components was prepared.

Silver trifumyroacetylacetonate 0g Polyvinyl butyral 18g 2-t-butyl-8-(3-t-butyl-2-hydroxy-5methylbenzyl)-4-methylphenylacrylate 8g Methyl ethyl ketone 185g Toluene
55g This solution is homogenized by stirring for about 2 hours and then has an average pore size of 1.5μ.
passed through a filter of m. This solution was applied using a small blade coater. The drying conditions were 10 minutes at 50°C, and then storage at 22°C and 50% RH.

The coating was dried under safe light. After that, palladium was vacuum-deposited to form palladium nuclei on the surface of the material.

Then, it was heated at 140'C for 110 seconds using a roll heater. The reflectance was 42%. 6 for this sample
He-Ne laser light with an emission wavelength of 33 nm (beam diameter 3 μm).

Laser recording was performed using a light emitting output of 3 mW). A pit of 3 μm was formed in the exposed area.

Examples 1 to 5 demonstrate that the present invention is effective.

(Effects of the Invention) According to the present invention, a flexible and stable digital recording material that can be laser recorded can be provided.

(1 other person)

Claims (1)

[Scope of Claims] (1) The reflectance of the metallic silver-containing layer formed by the reaction of an organic solvent-soluble silver compound and a reducing agent in the presence of silver or metal development nuclei nobler than silver is 10 to 90%. optical recording material. (2) An optical recording material according to claim (1), which contains photosensitive silver halide microcrystals and can be preformatted by pattern exposure. (3) The organic solvent soluble silver compound, the reducing agent, and a metal development nucleus containing silver or a metal nobler than silver are combined at least 70%
Claims (1) and (1) by heating to a temperature of ℃ or higher
2) A manufacturing method for manufacturing the optical recording material described above. (4) The optical recording material according to claims (1) and (2),
A recording method that records information by causing changes in reflectance by irradiating pulsed laser light.