JPS5816888A - Lasers-recording film - Google Patents

Abstract

PURPOSE:To obtain a laser-recording film capable of giving records with an optically high density difference by a low output lasers by coating a recording medium containing a specific light absorber and nitrocellulose on a base plate. CONSTITUTION:A recording medium is obtained by dissolving 1-50wt% a light absorber (A) of formulasI-III[where X is H, (substituted)alkyl, halogen or nitro, Y is H, alkyl, phenyl or cyano, Z is H, alkyl or halogen, M is Co, Ni, Pd or Pt, and n is 1-4], having such a property that a strong absorptivity exhibits in the wave length region of laser and the absorptivity is lost by decomposition by thermal effect in the presence of nitrocellulose, and 99-50wt% nitrocellulose (B) in a solvent (e.g., methyl cellosolve). Then, the recording medium is coated on a base material (e.g., polycarbonate) having a transmission to laser and a heat resistance to obtain a recording film. The film is subjected to irradiation of laser focused into spot beam of 2 microns or less for recording.

Description

DETAILED DESCRIPTION OF THE INVENTION In particular, the present invention relates to a novel laser recording film which has a laser beam absorption ability and loses its laser beam absorption ability at a portion irradiated with the laser beam.

In recent years, there has been an increasing demand for recording and reproducing information such as images and sounds at high speed, high density, and easily, and various methods have been proposed and some have been put into practical use. There is.

Among them, the method of recording on film with a laser is the so-called heat mode recording method, in which the laser beam narrowed down by a lens is focused on the recording layer on the substrate, and records are recorded using a heating element, unlike the conventional thermal recording method. Since it is possible to record without directly contacting the heat-sensitive recording layer, problems such as heat capacity of the heating element and heat diffusion do not occur, and high-speed and high-density recording becomes possible. The heat mode recording method using a laser causes a physical or chemical change in the recording layer in the area irradiated with the laser beam based on the thermal effect of the laser beam, thereby creating a gap between the irradiated spot and the non-irradiated area. This is a recording method that creates an optical density difference between the images. Conventionally, the recording film used in this recording method is a recording film in which metals such as molybdenum, indium, bismuth, tellurium, etc. are bonded into a thin film on a substrate such as polyester by methods such as vacuum deposition or sputtering. It is possible to record by irradiating this with laser light to partially evaporate the metal, and it has been partially put into practical use for creating master discs for video discs. However, since the metal used in this recording film has a high laser light reflectance and therefore has a low laser light absorption efficiency, the laser light required for recording requires a large output and the laser generator is large. It is not an economically advantageous recording film. In contrast to this recording film, a recording film that includes fine particles such as carbon flick that absorbs heat and a coating material that binds an autooxidation binding substance such as nitrocellulose has been proposed (Japanese Patent Application Laid-Open No. 48-481).
No. 3632). This recording film enables negative and positive recording by irradiating laser light to transfer fine particles such as carbon black to other recording tapes. It is essential that the substance be transferred by escaping it from the recording film using laser light. Therefore, it is difficult to obtain high-density recording due to the granularity of the fine particles, and a high output laser beam is still required to obtain an optically high density difference, which is the problem with recording films using metal thin films as mentioned above. The issue has not yet been resolved. In addition, as a recording film that can record with lower output laser light, we have developed dyes such as methylene blue and brilliant green that have strong absorption characteristics in the wavelength range of the laser light used for recording and that absorb light and generate heat. A recording film coated with a recording material bonded to an organic substance that vaporizes at low temperatures, such as cellulose, has been proposed (Japanese Patent Application Laid-open No. 87595/1983).

This recording film is capable of recording by exposing vaporizable organic substances such as nitrocellulose to a laser beam, and at the same time decomposing and dissolving the dye, but this recording method also This method requires mass transfer by vaporizing volatile organic substances such as nitrocellulose. Therefore, it is not only difficult to say that the power of the laser light used for recording has been sufficiently reduced;
Since there is a bulge around the irradiated spot of the laser beam, it tends to cause noise when reading the recording film, and the wavelength range of the laser beam used is limited to the visible light range, It has the disadvantage that it cannot use light in the near-infrared region like a laser.

In view of this situation, the present inventors have developed a recording film that can obtain a high optical density difference with low-output laser light by using the above-mentioned heat-absorbing fine particles and organic materials. In contrast to recording methods that utilize movement, we conducted research on a method that utilizes chemical changes caused by the thermal action of laser light. As a result, some light absorbers are chemically stable against laser light when used alone, but when exposed to laser light in combination with nitrocellulose, they become extremely susceptible to thermal effects. causing chemical decomposition,
We have discovered that there are compounds that lose their light absorption ability. Next, when a recording film was created using this and irradiated with laser light, it was found that compared to conventional recording methods, not only was it possible to obtain a high optical density difference with a low-output laser light, but also the laser light The present invention was achieved by discovering that it is possible to extremely reduce the swelling around the irradiated spot.

The recording film of the present invention not only allows recording using near-infrared light such as that of a semiconductor laser by selecting a light absorbing agent, but also completely eliminates the need for 4-phenomenon processing such as silver halide photography, and Real-time laser recording is possible in which the output of the laser beam used for recording is lowered and used as a reading beam and l-.

That is, the present invention provides a substrate with: (1) a light absorbent that has strong absorption ability in the wavelength range of the laser beam used for recording and which decomposes and loses its absorption ability in the coexistence of nitrocellulose; and (2) nitrocellulose. The object of the present invention is to provide a laser recording film coated with a recording medium containing the present invention.

The light absorbent used in the present invention is a substance that has a strong absorption ability in the wavelength range of the laser light used for recording, and is easily decomposed by thermal action and loses its absorption ability in the coexistence of nitrocellulose. . Through research conducted by the present inventors, it has been found that various metal complexes and aminium salts have this property. Although these metal complexes and aminium salts are chemically stable when heated or exposed to laser light alone, when they are heated or exposed to laser light in coexistence with nitrocellulose, their own decomposition temperature increases. It has the property that it easily undergoes chemical decomposition at a much lower temperature and loses its absorption ability. Although the mechanism of chemical decomposition is not necessarily clear, it is presumed that the strong oxidation that appears when nitrocellulose is heated accelerates the chemical decomposition of metal complexes and aminium salts, causing them to lose their absorption capacity. That is, the light absorbent used in the present invention is an absorbent that has the property of absorbing laser light and causing chemical decomposition due to its oxidation action, thereby losing its absorption ability. There are six types of such absorbents: aromatic diamine metal complexes, aliphatic diamine metal complexes, aromatic dithiol metal complexes, aliphatic dithiol metal complexes, mercaptophenol metal complexes, and arylaminium salts. can be given. (1) The aromatic diamine metal complex has the general formula (1) (wherein, It is a compound represented by nickel, cobalt, palladium, platinum), among which bis(4-chloro-0-
phenylene diamino) nickel (absorption extremely thick wavelength'max
800””, molar extinction coefficient ε66600) and bis(4-methyl-〇-phenylenediamino)nickel (
λrTlaX795ITn1ε55100) is preferred because it is easy to synthesize and has excellent compatibility with nitrocellulose.

(2) Aliphatic diamine metal complexes are represented by the general formula (II) (wherein Y represents hydrogen, an alkyl group, a phenyl group, or a cyano group, and M represents nickel, cobalt, palladium, or platinum). Among them, bis(diiminosuccinonitrilo)nickel (λ+mx 700
nm 1 ε23500) and bis(diiminosuccinonitrilo)palladium (2 pieces, 705, ε83
00) is preferred because it is easy to synthesize and has excellent compatibility with nitrocellulose.

Further, (3) the aromatic dithiol metal complex has the general formula (I) (wherein, Z is hydrogen, an alkyl group, or a halogen group, and n is 1
~4, M is nickel, cobalt, palladium, platinum, m is an integer of -1 or -2, A is m -1
When m is -2, it is a monovalent cation; when m is -2, it is a divalent cation.
Nickel(II) tetra-n-butylammonium (λ
max890 songs λε16270) and screws (1,2
, 3,4-tetrachloroo-5,6-sithioferto) nickel (IT) Tetra-n-butylammonium (λmaX885 nm1ε15700) is preferred because it is easy to synthesize and has excellent compatibility with nitrocellulose.

In addition, (4) the aliphatic dithiol metal complex is -(
In the formula, E represents hydrogen, an alkyl group, or a phenyl group; p represents an integer value of 2 or O; M represents nickel, cobalt, palladium, or platinum when p is 2; and vanadium, chromium, or molybdenum when p is 3. is a compound represented by
Among them, especially bis[cis-1,2-bis(p-methoxyphenyl)ethylene-1,2-dithiolate]nickel (λmaX920nm1 ε35000) and bis(cis-1,2-bisphenylethylene-),2-dithiolate ) Platinum (λr11aX800, ε51600
) and Tris (preferable because they are easy to form and have excellent compatibility with nitrocellulose).

(5) The mercaptophenol metal complex has the general formula (2) or (Vl) (where 0 is hydrogen, an alkyl group, or a halogen group, M is nickel, cobalt, palladium, or platinum, and m is -1 or an integer of -2, A is a monovalent cation when m is -1, and a divalent cation when m is -2), especially bis(1-mercapto- 2-naphthoL/-))nickel(II)tetra-n
-butylammonium (λr11aX1100.nm,
ε12290 ) and bis(1-mercapto-2-felt)nickel(It)tetra-n-butylammonium (λ□, 1025 nm, ε12700) are preferred because they are easy to synthesize and have excellent compatibility with nitrocellulose. .

Furthermore, (6) OK - Ruaminiram salts have the general formula %
Formula % (In the formula, R1 and R2 are the same or different alkyl groups, R3 is hydrogen, argyl, phenyl, benzyl group, m is an integer of +1 or +2, ■, is a monovalent when m is +1 is an anion, and when 01 is +2, it indicates a divalent anion), and is a compound represented by
-bis(p-dimethylaminophenyl) aminium iodide (ε12880 to λrTIIX740, λma
ε32890 to X1000), 4.4'-bis(p-
diethylaminophenyl) aminium fluoroborate (ε1B800 for λRyu x730, ε3 for λRyuX99゛5
8690) and bis(p-diethyl 11-aminophenyl) (N,N-bis(p-diethyl, no.

(aminophenyl) -47-aminobiphenyl] aminium hexafluoroantimone) (λffaX600
ε2600 for λ111ax1055, ε24300 for λ111ax1055
) is preferred because it is easy to synthesize and has excellent compatibility with nitrocellulose. These light absorbers described above decompose due to thermal action in the coexistence of nitrocellulose and lose their light absorbing ability.For example, when heated, the light absorbing agent decomposes at 200°C or less and loses its light absorbing ability. Moreover, instead of heating, the absorption ability is lost by irradiating the material with a laser beam having a wavelength close to the maximum absorption wavelength of the light absorbent.

The laser recording film of the present invention is prepared by mixing and dissolving the above-mentioned light absorbent and one course of nitrocell and other media as necessary in a suitable solvent. Polyethylene terephthalate, which transmits light and has heat resistance.
It is obtained by coating on a plastic film such as polycarbonate or a transparent substrate such as glass. When reading information recorded with a laser beam, unlike the case where the amount of transmitted light of the reading laser beam is detected, when reading by the amount of reflected light of the reading laser beam, metal is deposited on the substrate and then the metal is evaporated onto the substrate. The laser recording film of the present invention can be obtained by applying a recording medium containing the above-mentioned light absorbent and nitrocellulose onto the vapor deposited layer. Further, in a recording medium coated on a substrate, the addition ratio of the light absorbing agent to nitrocellulose is 1 to 50% by weight, but usually 3 to 30% by weight is preferable. If the addition ratio is large, the adhesion between the coating film and the substrate will deteriorate, and if the addition ratio is small, it will be difficult to obtain a sufficient optical density difference (
Become. In order to improve the adhesion between the coating film and the substrate and the economic stability of the coating film, the recording medium may be coated with acrylic resins such as polymethyl acrylate or polymethyl methacrylate, or cellulose acetate. Cellulose derivatives other than nitrocellulose, such as polyvinyl chloride,
An organic polymer compound such as a vinyl resin such as polyvinyl chloride-polyvinyl acetate copolymer may also be added. Solvents for dissolving the light absorber and nitrocellulose include ketone solvents such as acetone and methyl ethyl ketone, alcohol solvents such as ethanol and isopronochrome, cellosolve solvents such as methyl cellosolve and ethyl cellosolve, ethylene glycol monomethyl ether, and diethylene glycol. It is possible to use any one or more solvents such as glycol ether ester solvents (monomethyl ether acetate), chlorine hydrocarbon solvents such as dichloromethane, and chloroform.

In order to perform laser recording by irradiating the laser recording film of the present invention with a laser beam, a laser beam having a wavelength in the absorption wavelength region of the light absorbing agent contained is selected from various semiconductor lasers, helium neon lasers, etc. Real-time laser recording with a high optical density difference using high-density, low-energy laser light can be achieved by condensing the light into a spot beam of usually less than 2μ using the laser lens used and irradiating it onto the recording film. It becomes possible. That is, the laser recording film of the present invention is capable of obtaining extremely high density and optically high density difference using low-output laser light, and can also use laser light in the near-infrared region by selecting a light absorber.
The laser beam used for recording can be directly used as a reading beam by reducing its output, it is a real-time recording that does not require post-processing such as fixing the phenomenon, and it is not sensitive to room light. It has the advantage of not requiring darkroom operations, and can be widely applied to micro images, COM, micro facsimiles, original plates for phototypesetting, optical video discs, optical audio discs, etc.

The present invention will be explained below with reference to examples.

All parts in the examples represent parts by weight.

Example 1 Composition of 200 parts of ethyl cellosolve acetate, 10 parts of nitrocellulose (Asahi Kasei T, IG 1/2), and 2 parts of bis(4-mef-O-phenylenediamine) nickel, stirred and dissolved. The material was coated onto a polyethylene terephthalate film using a spinner and dried under specified conditions to form a reddish-purple coating surface of about 0.515-μm. Next, a semiconductor laser beam (GaAIAS laser, 78
0 nm, optical output smw) was applied in a linear sweep. As a comparative test, a recording film was similarly carried out using 2 parts of carbon black instead of bis(4-methyl-〇-phenylenediamine) nickel, and the laser beam was swept in a straight line and irradiated. As a result of observing the laser irradiated area of both with an electron microscope, it was found that when carbon black was used, the trajectory of the laser beam could be seen slightly, but when 1 part of bis(4-methyl-〇-phenylene diamine) nickel was used, the trajectory of the laser beam was slightly visible. The straight lines were extremely clear, and there was almost no swelling near the irradiated area, and observation using an optical microscope revealed that the unirradiated area was reddish-purple, while the irradiated area was discolored to yellow. . When this recording film was placed on the heating plate of a micro melting point meter (manufactured by Tokyo Hyakubon Seisaku Shin) and heated, the color changed from reddish-purple to yellow when the temperature reached about 16,060. Next, the near-infrared light transmittance of the recording film before and after heating was measured (with a Multipa 16-one-pass self-recording spectrophotometer manufactured by Shimadzu Corporation). As a result, the transmittance at 780 nm was 1 before irradiation and 3 after irradiation.

Example 2 In place of 200 parts of ethyl cellosolve acetate in Example 1, 7150 parts of methyl ether were used, and in place of 2 parts of bis(4-methyl-〇-phenylenediamine) nickel, 1 part of bis(iminosuccinonitrilo)nickel was used. A green recording film was obtained in the same manner as in Example 1 except for this. When this film was placed on the heating plate of a micro melting point meter and heated, the color changed from green to yellow when the temperature reached about 150°C. Next, the near-infrared light transmittance of the recording film before and after heating was measured. As a result, the transmittance at 700 nm was 1 before irradiation and 4 after irradiation.

Example 3 7 parts of nitromethacrylic acid resin and 2 parts of bis(1-methyl-6,4-dithioferrate) nickel (TI) tetra n-butylammonium were added to 200 parts of ethyl cellosolve acetate and stirred. A green recording film was obtained in the same manner as in Example 1. Next, a semiconductor laser beam (Gah, s-based laser, 905
nm, optical output 5 mw) in a straight line and observed with an electron microscope, an extremely clear straight line was drawn, and no swelling was observed near the irradiated area, and observation with an optical microscope showed that the irradiated area was It was found that the color had changed to yellow-green. It was also found that when this recording film was placed on the heating plate of a micro melting point meter and heated, the color changed from green to yellow-green when it reached about 170°C, and turned yellow at about 180°C. Next, the near-infrared light transmittance of the recording film before and after heating was measured. As a result, the transmittance at 905 nm was 1 before irradiation and 2 after irradiation.

Example 4 Bis[cis-1,2-bis(p-methoxyphenyl) ) Ethylene-1,2-cy-oleate] A green recording film was obtained in the same manner as in Example 6 except that 2 parts of nickel was used. In addition, semiconductor laser beam (GaAS
The locus of the system laser (905 nm 1 optical output 5 mW) is clear, and the heating with a micro melting point measuring device produces a temperature of about 160 nm.
00, the color changed to yellow, and the light transmittance at 905 nm before and after heating was 1 before irradiation, and after irradiation.

Example 5 Bis(1-mercaptolate-
A dark brown recording film was obtained in the same manner as in Example 1 except that 2 parts of nickel (II) tetra-n-butylammonium (2-nandolate) was used. Next, the YAG laser beam 00 focused on the coating surface changes the color to yellow, and the 1
The light transmittance at 1060n was set as 1 before irradiation and after irradiation.

Example 6 4,4'-bis(p-
A dark blue recording film was obtained in the same manner as in Example 1 except that 2 parts of dimethylaminophenyl) aminium iodide was used.

Next, a semiconductor laser beam (GaA1!) is focused on the coating surface.
, AS-based laser, 780 nm, optical output 5 mw), the locus is clear, and the heating by the micro melting point meter shows a
It turned yellow at 0°C, and the light transmittance at 780 nm before and after heating was 1 before irradiation and 4 after irradiation. , Patent applicant Mitsui Toatsu Chemical Co., Ltd. 20-

Claims (1)

[Claims] 1) On the substrate, ■ in the wavelength range of the laser light used for recording,
1. A laser recording film coated with a recording medium containing a light absorbent that has a strong absorption ability and which decomposes and loses its absorption ability in the coexistence of nitrocellulose, and (1) nitrocellulose.