JPH022715B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photothermal conversion recording medium that records and reproduces information at high density by utilizing the photothermal conversion effect of a laser or the like. The present invention relates to a photothermal conversion recording medium that effectively absorbs light, converts it into thermal energy, and enables high-density recording and optical reproduction using a laser or the like.

The photothermal conversion recording medium used in optical disk technology is
High-density information can be recorded by optically detectable small (eg, about 1 micron) pits formed in a thin photothermal recording layer on a substrate in the form of spiral or circular tracks. To write information on such a disk, a focused laser is scanned over the surface of the laser-sensitive layer, and only the surface irradiated by the laser beam forms a pit, which is then shaped into a spiral or circular track. Form.
The laser sensitive layer can absorb laser energy to form optically detectable pits. For example, in the heat mode recording method, the laser energy irradiated to the laser sensitive layer is absorbed and converted into thermal energy, and a small pit can be formed at that location by evaporation or deformation. It is possible to form pits having oxidation degree differences, reflectance differences, or density differences caused by optically detectable chemical changes.

The information recorded on this optical disk is detected by scanning a laser along the track and reading the optical changes in the pitted and non-pitted areas. For example, a laser is scanned by a track and the energy reflected by the disk is monitored by a photodetector. When no pits are formed, the output of the photodetector decreases, while when pits are formed, the laser beam is sufficiently reflected by the underlying reflective surface and the output of the photodetector increases.

As a recording medium used for such optical discs,
So far, methods have been proposed that mainly use inorganic materials such as metal thin films such as aluminum vapor-deposited films, bismuth thin films, tellurium oxide thin films, and chalcogenite amorphous glass films.

On the other hand, a liquid crystal element that can use a photothermal conversion recording method can form an optical image corresponding to an optical signal generated from a laser or the like. Conventionally, a liquid crystal element is prepared in which a mixed liquid crystal of a nematic crystal and a cholesteric crystal with negative dielectric anisotropy or a smectic liquid crystal with positive dielectric anisotropy is arranged between two glass substrates, and this liquid crystal element When a laser beam or the like is irradiated onto the area, thermal energy is generated locally at that area, and the area is heated to the isotropic phase. after that,
Rapid cooling forms a liquid crystal phase with a random orientation different from the initial uniform orientation. As a result, light scattering occurs at the location where the laser beam is irradiated, resulting in a difference in optical characteristics between the liquid crystal layer in the background region and the uniformly aligned liquid crystal layer.

This type of liquid crystal element can also erase an optical image formed by laser writing using the method described above. That is, by providing electrodes on each of the two substrates that make up the liquid crystal element, and heating the entire liquid crystal element with a laser beam and another heat source (for example, a heater), the liquid crystal phase is heated to the isotropic phase. For example, the optical image previously formed by writing can be erased by cooling until a homeotropic structure is formed in the case of a smectic liquid crystal, or a grunge structure in the case of a cholesteric nematic liquid crystal. can.

A liquid crystal device using such a photothermal recording method does not require a matrix electrode structure to form pixels, and can form an image pattern simply by scanning optical signals converted from electrical signals. The advantage is that it can be displayed on a large screen. However, when a laser beam is used, the efficiency of absorbing the laser beam and converting it into thermal energy is not sufficient, and even if an optical signal is scanned, sufficient writing cannot be performed. Therefore, conventionally,
For example, “Society of Information Display
International Symposium, Digest of
Technical Oaper”P.P34-49, 172-187, 238
253 (1982), a guest-phos type photothermal recording type liquid crystal element in which a black dye is mixed into a smectic liquid crystal has been proposed.

By the way, semiconductor lasers that are small, low cost, and capable of linear modulation have been developed in recent years, but the oscillation wavelength of these lasers often has a wavelength of 700 nm or more, and in general, argon Laser light power is smaller than gas lasers such as lasers and helium-neon lasers. Therefore, when performing photothermal conversion recording using such a conductor laser, it is effective for the absorption characteristics of the laser sensitive layer to have an absorption peak on the long wavelength side (generally in the region of 700 mm to 850 mm).

However, conventional photothermal conversion recording media do not have sufficient efficiency in absorbing laser light and converting it into thermal energy. Since the layer has a high reflectance to laser light, it has the disadvantage that the laser utilization rate is low and high sensitivity characteristics cannot be obtained. This has the disadvantage of complicating the layer structure. For this reason, in recent years, research has been carried out on organic compounds whose substances can be changed by light energy in a relatively long wavelength range. For example, US Pat. No. 4,315,983 “Reseach Disclosure” 20517
(1981.5) and the pyrylium dye disclosed in J.Vac.
Scl.Technol., 18(1), Jan./Feb.1981, P105~
It is known that the organic compound containing the squarerium dye disclosed in P109 is sensitive to a laser of 700 nm or more.

However, organic compounds generally have problems such as their absorption characteristics becoming more unstable in the longer wavelength region and being more easily decomposed by a slight temperature rise.

On the other hand, when a guest-host type photothermal conversion recording method liquid crystal element uses the semiconductor laser described above, it absorbs laser light due to its low power.
The drawback is that the conversion efficiency into thermal energy is not sufficient and that high power or low speed optical signal scanning is required. Further, in the liquid crystal element using the above-mentioned black dye, a white image pattern is formed on a black background, which has the disadvantage that it does not provide a good display from an ergonomic point of view.

As mentioned above, it is necessary to satisfy various characteristics required of photothermal conversion recording media used as optical disks and liquid crystal elements, so it is not always possible to develop photothermal conversion recording media that are fully satisfactory in terms of practicality. The current situation is that we cannot say that there are.

Accordingly, a first object of the present invention is to provide a new and useful photothermal conversion recording medium.

The second object of the present invention is photothermal conversion, which has absorption characteristics in the visible and near-infrared wavelengths, effectively absorbs light, converts it into thermal energy, and enables high-density recording and optical reproduction. The goal is to provide recording media.

A third object of the present invention is to provide a thermally stable photothermal conversion recording medium that eliminates the above-mentioned drawbacks.

A fourth object of the present invention is to provide a novel photothermal conversion recording medium for optical discs.

A fifth object of the present invention is to provide a photothermal conversion recording medium for optical disks that is highly sensitive at wavelengths in the visible and near infrared regions and has a sufficient S/N ratio.

A sixth object of the present invention is to provide a liquid crystal element that can use a novel photothermal conversion recording method.

A seventh object of the present invention is to provide a liquid crystal element using a photothermal conversion recording method that can form an optical image pattern according to optical signal scanning from an optical signal oscillator using a laser oscillator.

Such an object of the present invention is the following general formula [],
This is achieved by a photothermal conversion recording medium containing an azulenium salt compound represented by [ ] and [ ].

general formula In the general formulas [], [] and [],
R ₁ to _{R 5} are hydrogen atoms, halogen atoms (chlorine atoms,
bromine atom, iodine atom) or a monovalent organic residue, and X represents a substituted or unsubstituted 5-, 6-, or 7-membered
Represents a group of atoms necessary to form a member aromatic ring. Monovalent organic residues can be selected from a wide variety of groups, but especially alkyl groups (methyl, ethyl, n-propyl, isopropyl, n-
butyl, t-butyl, n-amyl, n-hexyl, n-octyl, 2-ethylhexyl, t-octyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), substituted or unsubstituted aryl groups (phenyl , tolyl, xylyl, ethyl phenyl, methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl,
dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.), substituted or unsubstituted heterocyclic groups (pyridyl, quinolyl, carbazolyl, furyl,
thienyl, pyrazolyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenyl-1-methylethyl, promobenzyl, 2-promophenylethyl, methylbenzyl, methoxybenzyl, nitrobenzyl), acyl groups (acetyl, puwapionyl, butyryl,
valeryl, benzoyl, trioyl, naphthoyl, phthaloyl, furoyl, etc.), substituted or unsubstituted amino groups (amino, dimethylamino, diethylamino, dipropylamino, acetylamino, benzoylamino, etc.), substituted or styryl groups (styryl, dimethylaminostyryl) , diethylamino, dipropylaminostyryl, methoxystyryl, ethoxystyryl, methylstyryl, etc.), nitro group, hydroxy group, mercapto group, thioether group, carboxyl group, carboxylic acid ester, carboxylic acid amide, cyano group, unsubstituted arylazo group (phenylazo, α-naphthylazo, β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo, tolylazo, etc.)
I can list some. In addition, an aromatic ring formed by R ₁ and X, an aromatic ring formed by
Aromatic rings substituted or unsubstituted with at least one combination of R ₂ , R ₂ and R ₃ , R ₃ and R ₄ , and R ₄ and R ₅ (benzene, naphthalene, chlorobenzene, ethylbenzene, methoxybenzene) ), heterocycles (furan, benzofuran, pyrrole,
thiophene, pyridine, quinoline, etc.) or aliphatic chains (dimethylene, trimethylene, tetramethylene, etc.) may form a ring. A represents a divalent organic residue bonded via a double bond. A specific example of the present invention containing such A is represented by the following general formula (1).
-(11) can be mentioned. However, Q in the formula represents the azulenium skeleton shown below, and the right side excluding Q in the formula represents A.

Azulenium skeleton (Q) general formula In the formula, R ₁ to R ₅ and X have the same definitions as defined above.

In the formula, R ₁ to R ₅ and X have the same definitions as defined above.

In the formula, R' ₁ to R' ₅ represent a hydrogen atom, a halogen atom (chlorine atom, bromine atom, iodine atom) or a monovalent organic residue, and X represents a substituted or unsubstituted 5
6-membered, 6-membered or 7-membered aromatic ring. Monovalent organic residues can be selected from a wide range of options, but especially alkyl groups (methyl, ethyl,
n-propyl, isopropyl, n-butyl, t-
butyl, n-amyl, n-hexyl, n-octyl, 2-ethylhexyl, t-octyl, etc.),
Alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, ethyl phenyl, methoxy phenyl, ethoxy phenyl,
chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.),
Substituted or unsubstituted heterocyclic groups (pyridyl, quinolyl, carbazolyl, furyl, thienyl, pyrazolyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenyl-1-methylethyl, promobenzyl, 2 -promophenylethyl, methylbenzyl, methoxybenzyl, nitrobenzyl), acyl groups (acetyl, propionyl, butyryl, valeryl, benzoyl, triooyl, naphthoyl, phthaloyl, furoyl, etc.), substituted or unsubstituted amino groups (amino, dimethylamino) , diethylamino, dipropylamino, acetylamino, benzoylamino, etc.), substituted or unsubstituted styryl groups (styryl, dimethylaminostyryl, diethylaminostyryl, dipropylaminostyryl, methoxystyryl, ethoxystyryl, methylstyryl, etc.), nitro group, hydroxy group, mercapto group,
Thioether group, carboxyl, carboxylic acid ester, carboxylic acid amide, cyano group, substituted or unsubstituted arylazo group (phenylazo, α-
naphthylazo, β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo, tolylazo, etc.). Also, the aromatic ring of R′ ₁ and X′, the aromatic ring of X′ and R′ ₂ , R′ ₂ and R′ ₃ , R′ ₃ and R′ ₄
,
and aromatic rings (benzene _{, naphthalene} , chlorobenzene, ethylbenzene, methoxybenzene, etc.), heterocycles (furan,
benzofuran, pyrrole, thiophene, pyridine, quinoline, etc.) or aliphatic chains (dimethylene,
(trimethylene, tetramethylene, etc.) may form a ring.

Further, the azulenium skeleton represented by Q may be symmetrical or asymmetrical. Z is
Represents an anionic residue. R ₆ is a hydrogen atom, a nitro group, a cyano group, an alkyl group (methyl, ethyl,
propyl, butyl, etc.) or an aryl group (phenyl, tolyl, xylyl, etc.), where n is 0,
Represents 1 or 2.

In the formula, R ₁ to R ₅ , X and Z have the same definitions as defined above.

In the formula, R ₁ to R ₅ , X and Z have the same definitions as defined above. R″ ₁ to R″ ₆ represent a hydrogen atom, a halogen atom (chlorine atom, bromine atom, iodine atom) or a monovalent organic residue. Monovalent organic residues can be selected from a wide variety of groups, but especially alkyl groups (methyl, ethyl, n-
Propyl, isopropyl, n-butyl, t-butyl, n-amyl, n-hexyl, n-octyl,
2-ethylhexyl, t-octyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, ethyl phenyl,
methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.), substituted or unsubstituted heterocyclic groups (pyridyl, quinolyl,
carbazolyl, furyl, thienyl, pyrazolyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenyl-1-
Methyl ethyl, bromobenzyl, 2-promophenylethyl, methylbenzyl, methoxybenzyl, nitrobenzyl), acyl group (acetyl,
substituted or unsubstituted amino groups (amino, dimethylamino, diethylamino, dipropylamino, acetylamino, benzoylamino, etc.), substituted or styryl groups (styryl), butyryl, valeryl, benzoyl, triooyl, naphthoyl, phthaloyl, furoyl, etc. , dimethylaminostyryl, diethylaminostyryl,
dipropylaminostyryl, methoxystyryl,
ethoxystyryl, methylstyryl, etc.), nitro group, hydroxy group, mercapto group, thioether group, carboxyl, carboxylic acid ester, carboxylic acid amide, cyano group, substituted or unsubstituted arylazo group (phenylazo, α-naphthylazo, β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo, tolylazo, etc.). Also, R″ ₂ and R″ ₃ , R″ ₃ and R″ ₄ ,
Aromatic rings (benzene _{, naphthalene , chlorobenzene} ,
ethylbenzene, methoxybenzene, etc.), heterocycles (furan, benzofuran, pyrrole, thiophene, pyridine, quinoline, etc.) or aliphatic chains (dimethylene, trimethylene, tetramethylene, etc.)
A ring may be formed by

In the _formula ,
- Represents a group of nonmetallic atoms necessary to complete a nitrogen-containing heterocycle such as quinoline, isoquinoline, or indole; such a heterocycle includes halogen atoms (chlorine, bromine, iodine), alkyl groups (methyl,
(ethyl, propyl, butyl, etc.), aryl groups (phenyl, tolyl, xylyl, etc.), and the like. R ₇ is an alkyl group (methyl,
ethyl, propyl, butyl), substituted alkyl groups (2-hydroxyethyl, 2-methoxyethyl, 2-hydroxyethyl, 3-hydroxypropyl, 3-methoxypropyl, 3-ethoxypropyl, 3-chloropropyl, 3-promo) propyl, 3-carboxypropyl, etc.), cyclic alkyl groups (cyclohexyl, cyclopropyl), allyl, aralkyl groups (benzyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl, α-naphthylmethyl, β-naphthylmethyl ),
Substituted aralkyl groups (methylbenzyl, ethylbenzyl, dimethylbenzyl, trimethylbenzyl,
chlorobenzyl, bromobenzyl, etc.), aryl groups (phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl) or substituted aryl groups (chlorophenyl, dichlorophenyl, trichlorophenyl, ethyl phenyl, methoxyphenyl, dimethoxyphenyl, (aminophenyl, nitrophenyl, hydroxyphenyl, etc.). m represents 0 or 1 and Z has the same definition as defined above.

(7) Q = CH-R ₈ Z In the formula, R ₈ is a substituted or unsubstituted aryl group (phenyl, tolyl, xylyl, biphenyl, α-naphthyl, β-naphthyl, anthralyl, pyrenyl, methoxyphenyl, dimethoxyphenyl) enyl, trimethoxyphenyl, ethoxyphenyl, diethoxyphenyl, chlorophenyl, trichlorophenyl, bromophenyl, dibromophenyl, tribromophenyl, ethyl phenyl, diethylphenyl, nitrophenyl, aminophenyl, dimethylaminophenine, diethylaminofenyl enyl, dibenzylaminophenyl, dipropylaminophenyl, morpholinophenyl, piperidinyl phenyl, piperazinophenyl, diphenylaminophenyl, acetylaminophenyl, benzoylaminophenyl, acetylphenyl, benzoylphenyl (enyl, cyanophenyl, etc.), and Z has the same definition as defined above.

(8) Q = CH-R ₉ Z where R ₉ represents a monovalent heterocyclic group derived from a heterocycle such as furan, thiophene, benzofuran, thionaphthene, dibenzofuran, carbazole, phenothiazine, phenoxazine, pyridine, etc. Z has the same definition as defined above.

In the formula, R ₁₀ is a hydrogen atom, an alkyl group (methyl,
ethyl, propyl, butyl) or substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, biphenyl, ethyl phenyl, clophenyl, methoxyphenyl, ethoxyphenyl, nitrophenyl, aminophenyl, dimethylaminophenyl, α-naphthyl, β - Naphthyl, anthralyl, pyrenyl, etc.). _R8 and Z
has the same definition as defined above.

(10) Q = CH-C-C-R ₈ Z where R ₈ and Z have the same definitions as defined above.

In the formula, X ₂ represents an atomic group necessary to complete pyran, thiapyran, selenapyran, benzopyran, benzothiapyran, benzoselenapyran, naphthopyran, naphthothiapyran or naphthoselenapyran, which may be substituted. l is 0 or 1. Y represents a sulfur atom, an oxygen atom or a selenium atom. R ₁₁ and R ₁₂ are hydrogen atoms (methyl,
ethyl, propyl, butyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, chlorophenyl, biphenyl, methoxyphenyl, etc.), substituted or unsubstituted styryl group (styryl, p-methylstyryl, o-chlorostyryl, p-methoxystyryl, etc.), substituted or unsubstituted 4-phenyl 1,
3-butadienyl group (4-phenyl 1,3-butadienyl, 4-(p-methylphenyl) 1,3-
butadienyl, etc.) or a substituted or unsubstituted heterocyclic group (quinolyl, pyridyl, carbazolyl, furyl, etc.). Z is an anionic residue.

Specific examples of Z in the general formulas (1) to (11) include perchlorate, fluoroborate, sulfoacetate, iodide, chloride,
Represents anionic residues such as bromide, p-toluenesulfonate, alkylsulfonate, alkyldisulfonate, benzenedisulfonate, halosulfonate, picrate, tetracyanoethylene anion, tetracyanoquinodimethane anion, and the like.

Specific examples of the azulenium salt compounds used in the present invention are listed below.

Examples of compounds represented by the above general formula (1) Examples of compounds represented by the above general formula (2) Examples of compounds represented by the above general formula (3) Examples of compounds represented by the above general formula (4) Examples of compounds represented by the above general formula (5) Examples of compounds represented by the above general formula (6) Examples of compounds represented by the above general formula (7) Examples of compounds represented by the above general formula (8) Examples of compounds represented by the above general formula (9) Examples of compounds represented by the above general formula (10) Examples of compounds represented by the above general formula (11) Compounds represented by general formulas (1) and (2) are
Angewandte chemie Volume 78, No. 20, P. 937 (1966
It can be easily obtained by reacting an azulene compound with squaric acid or croconic acid in an appropriate solvent as described in 2006). Among the compounds represented by general formula (3), the compound where n=0 is Journal of the chemical Society, P.501
(1960) by heating the 1-formyl-azulene compound and the azulene compound in a suitable solvent in the presence of a strong acid, or
Journal of the chemical Society, P.1724～
By mixing a 1-ethoxymethylene azulenium salt compound and an azulene compound in a suitable solvent as described in P.1730 (1961), or
Journal of the chemical Society, P.359 (1961
It can be obtained by heating 2-hydroxymethylenecyclohexanone and an azulene compound in a suitable solvent in the presence of a strong acid as described in 2010). general formula
In (3), the compounds where n=1 and n=2 are:
Journal of the chemical Society, P.3591～
As described in P. 3592 (1961), it can be obtained by mixing an azulene compound and frondialdehydes or glutacondialdehydes in a suitable solvent in the presence of a strong acid.

The compound represented by general formula (4) is published in the Journal of
It can be easily obtained by heating an azulene compound and geryoxal in a suitable solvent in the presence of a strong acid as described in The Chemical Society, P. 3588 (1961).

The compound represented by general formula (5) is published in the Journal of
It can be obtained by heating a 1,3-diformyl azulene compound and an azulene compound in a suitable solvent in the presence of a strong acid as described in the Chemical Society, P. 501 (1960).

The compound represented by general formula (6) is published in the Journal of
the chemical Society, P.163-P.167 (1961)
It can be obtained by heating a 1-formyl azulene compound and a heterocyclic quaternary ammonium salt compound having an active methyl group in a suitable solvent as described in .

Compounds represented by general formulas (7), (8), (9) and (10) are shown in Journal of the chemical Society, P.1110
~P.1117 (1958), Journal of the chemical
Society, P.494-P.501 (1960) and Journal of
the chemical Society, P.3579-P.3593 (1961)
It can be obtained by mixing an azulene compound and a corresponding aldehyde compound in a suitable solvent in the presence of a strong acid as described in .

The compound represented by the general formula (11) can be obtained by reacting a 1-formyl-azulene compound with a compound represented by the general formula (12) in a solvent.

In the formula, X ₂ , Y, R ₁₁ , R ₁₂ , Z and l have the same definitions as defined above.

Reaction solvents used include alcohols such as ethanol, butanol and benzyl alcohol, nitriles such as acetonitrile and propionitrile, organic carboxylic acids such as acetic acid, acid anhydrides such as acetic anhydride, and alicyclics such as dioxane and tetrahydrofuran. Formula ethers, etc. are used.
Furthermore, aromatic hydrocarbons such as benzene can be mixed with butanol, benzyl alcohol, and the like. The temperature during the reaction can be selected from the range of room temperature to boiling point.

The photothermal conversion recording medium of the present invention can be used for optical disc recording. For example, a thin film 2 containing the above-mentioned organic compound is placed on a substrate 1 as shown in FIG.
can be assumed to have been formed. Such a thin film 2 can be formed by vacuum deposition of the compounds represented by the above-mentioned general formulas [], [] and [], and can also be formed by applying a coating liquid containing the above-mentioned organic compound in a binder. It can be formed even if it is twisted. When forming a film by coating, the above-mentioned organic compound may be contained in the binder in a dispersed state or in an amorphous state. Suitable binders can be selected from a wide variety of resins. Specifically, nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate,
Cellulose esters such as cellulose butyrate, cellulose myristate, cellulose palmitate, cellulose acetate/propionate, cellulose acetate/butyrate, cellulose ethers such as methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, polystyrene, polyvinyl chloride, polyacetic acid Vinyl resins such as vinyl, polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyvinyl hyloridone,
Styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, vinyl chloride
Copolymer resins such as vinyl acetate copolymers, polymethyl methacrylate, polymethyl acrylate, polybutyl acrylate, polyacrylic acid,
Acrylic resins such as polymethacrylic acid, polyacrylamide, and polyacrylonitrile, polyesters such as polyethylene terephthalate, poly(4,4'-isopropylidene diphenylene-co-
1,4-cyclohexylene dimethylene carbonate), poly(ethylene dioxy-3,3'-phenylene thiocarbonate), poly(4,4'-isopropylidene diphenylene carbonate-co-terephthalate), poly(4 , 4'-isopropylidene diphenylene carbonate), poly(4,4'-sec
-butylidene diphenylene carbonate), polyarylate resins such as poly(4,4'-isopropylidene diphenylene carbonate-block oxyethylene), or polyamides, polyimides, epoxy resins, phenolic resins, Polyolefins such as polyethylene, polypropylene, and chlorinated polyethylene can be used.

The organic solvent that can be used during coating varies depending on the type of binder and whether the above-mentioned compound is contained in the binder in a dispersed or amorphous state, but in general, , alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexane, amides such as N,N-dimethylformamide and N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane,
Ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, butyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichloroethylene, or benzene, toluene. , xylene, ligroin, monochlorobenzene, dichlorobenzene, and other aromatic compounds can be used.

Coating can be carried out using coating methods such as dip coating, spray coating, spinner coating, bead coating, Meyer bar coating, blade coating, roller coating, and curtain coating.

When forming the thin film 2 together with the binder, the content of the above-mentioned organic compound in the thin film 2 is 1 to 1.
90% by weight, preferably 20-70% by weight. Further, the dry film thickness or vapor deposited film thickness of the thin film 2 is 10 microns or less, preferably 2 microns or less.

As the substrate 1, plastics such as polyester, acrylic resin, polyolefin resin, phenolic resin, epoxy resin, polyamide, polyimide, glass, metals, etc. can be used.

The photothermal conversion recording medium of the present invention is obtained by forming the aforementioned thin film 2 (electromagnetic radiation sensitive layer) on the substrate 1 used as a support, but various auxiliary layers can be provided. For example, it is possible to use a substrate having a surface coating made of an inorganic or organic substance on the surface of the substrate 1 for the purpose of adjusting the thermal constant. Further, a protective layer made of a transparent material can be provided on the electromagnetic radiation sensitive layer 2, and this protective layer is effective in preventing mechanical damage, and
By forming the film to an appropriate thickness, it can be used as an antireflection film, which is also effective in improving sensitivity. Further, as shown in FIG. 2, a reflective layer 3 can be provided between the electromagnetic radiation sensitive layer 2 and the substrate 1. This reflective layer 3 can be a vapor deposited layer or a laminate layer of a reflective metal such as aluminum, silver, or chromium.

Furthermore, the optical recording medium of the present invention has a patent application filed in 1983-
It is possible to form a pregroup having functions such as a track guide groove and an address designation groove as described in the specification of No. 72374.

The photothermal conversion recording medium of the present invention, as shown in FIG.
820nm), argon gas laser (oscillation wavelength: 488,
515nm), helium-neon gas laser (oscillation wavelength: 632.8nm), other lasers with oscillation wavelengths from the visible region to the infrared region, various short pulse emitting lamps such as xenon flash lamps, infrared lamp light, or heaters. In this way, a pit 5 can be formed. The pitted area has a different reflectance than the unpitted area and therefore the pits are formed, for example by scanning electromagnetic radiation along the track,
A low-power laser is scanned along the above-mentioned track over the pit-formed portion and the pit-unformed portion, and the difference in reflectance can be read by a photodetector.

The effects of the present invention are listed below.

In the photothermal conversion recording medium of the present invention, the electromagnetic radiation sensitive layer has a high absorption efficiency for electromagnetic radiation, and recording can be performed using a low energy density helium-neon gas laser or xenon flash lamp.
Moreover, it is also effective for recording using a semiconductor laser having an oscillation wavelength on the long wavelength side. Also, the S/N ratio is high,
Good regeneration efficiency. Furthermore, the compound used in the present invention has the advantage of being extremely stable against heat.

In another specific example of the present invention, it can be applied as a liquid crystal element using a photothermal conversion recording method. for example,
As shown in FIG. 4, a cross-sectional view of the liquid crystal element of the present invention,
The liquid crystal composition 108 has the above-mentioned general formula [],
A liquid crystal in which compounds represented by [] and [] are dissolved is used. A suitable liquid crystal for use in the device of the present invention is a smectic liquid crystal, and particularly a phase A or C phase of a smectic liquid crystal having positive dielectric anisotropy is suitable. Such smectic liquid crystals are arranged in the smectic phase of a homeotropic structure until they are locally heated by a laser beam, and can undergo a phase change from the smectic phase of the homeotropic structure to the nematic phase to the isotropic phase as the temperature rises. . Next, when the phase is changed from the isotropic phase to the smectic phase under rapid cooling, a smectic phase with a focal conic structure having light scattering properties is formed. Therefore, when the smectic phase in a liquid crystal element is locally heated to an isotropic phase by irradiation with a laser beam, and then rapidly cooled, the area becomes a smectic phase of a focal conic structure, and this state has light scattering properties. Therefore, a still image pattern can be formed by scanning the optical signal using the laser beam described above.

Compounds capable of forming a smectic phase with positive dielectric anisotropy used in the liquid crystal element of the present invention include:
For example, JP-A-56-150030, JP-A-57-
Compounds described in JP-A-40429, JP-A-57-51779, etc. can be used.

The compounds represented by the above-mentioned general formulas [], [] and [] should be present in an amount of 0.1% by weight or more based on the liquid crystal.
It can be contained in the liquid crystal composition 108 preferably in a range of 1% by weight to 3% by weight.

Further, the liquid crystal element of the present invention can also use a mixed liquid crystal of a smectic liquid crystal and a cholesteric liquid crystal having positive dielectric anisotropy. The cholesteric liquid crystal is suitably contained in the liquid crystal composition 108 in an amount of 0.5% to 15% by weight, preferably 1% to 5% by weight.

Cholesteric liquid crystals that can be used in the present invention include cholesteryl chloride, cholesteryl bromide, cholesteryl iodide, cholesteryl nitrate, cholesteryl chlorodecanoate,
Cholesteryl butyrate, cholesteryl caprate, cholesteryl oleate, cholesteryl linoleate, cholesteryl urarate, cholesteryl myristate, cholesteryl heptycarbamate,
Examples include cholesteryl compounds such as cholesteryl decyl ether, cholesteryl lauryl ether, and cholesteryl oleyl ether.

A liquid crystal element using such a mixed liquid crystal undergoes a phase change from a homeotropic smectic phase to an isotropic phase by local heating with a laser beam, and when this is rapidly cooled, a focal conic structure smectic phase is formed as described above. Can be done.

A liquid crystal element recorded by the above-mentioned method is produced by heating the entire surface of the liquid crystal composition 108 using, for example, a heater to change the phase to an isotropic phase, and then applying the liquid crystal composition 108 to the substrates 101 and 102 (for example,
By applying an appropriate direct current or alternating current between the electrodes 103 and 104 provided on a plastic plate (such as a transparent glass plate or an acrylic plate) and slowly cooling it, a phase change occurs from an isotropic phase to a nematic phase to a smectic phase. can occur. At this time, since the liquid crystal in the smectic phase has positive dielectric anisotropy, the nematic liquid crystal is aligned in the direction of the electric field, and the smectic A phase or C phase of the homeotropic structure is further cooled, forming the written image pattern. will be deleted. Electrodes 103 and 104
is generally indium oxide, tin oxide or
It can be obtained with a transparent conductive film of ITO (Indium Tin Oxide), and if necessary, with a conductive film of metal such as aluminum, chromium, gold, or nickel. The electrodes 103 and 104 are desirably coated over the entire surfaces of the substrates 101 and 102, and do not necessarily have to have a predetermined pattern shape or matrix electrode structure. However, it is also possible to design a predetermined pattern shape or matrix electrode structure as desired.

In the liquid crystal element of the present invention, alignment control films 106 and 107 made of insulating material coatings can be provided on the electrodes 103 and 104, respectively. The alignment control films 106 and 107 have a surface structure capable of controlling the alignment direction of the liquid crystal composition 108 that is in contact with these critical surfaces to a desired state.
The alignment control films 106 and 107 also function as insulating films that can prevent the generation of current flowing through the liquid crystal composition 108. This type of alignment control films 106 and 107 can be made of, for example, silicon monoxide, silicon dioxide, aluminum oxide, zirconium, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon carbide, boron nitride, polyvinyl alcohol, polyimide. , polyamideimide, polyesterimide, polyparaxylyline, polyester, polycarbonate, povinyl acetal, polyvinyl chloride, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin, organosiloxane, polyethylene fluoride, etc. It can be obtained by forming a film using a substance by vapor deposition, dip coating, spinner coating, or spray coating.

The alignment control films 106 and 107 are coated with the liquid crystal composition 10 by rubbing the surface with cloth, paper, velvet, etc., or by using an oblique vapor deposition method when forming the film, depending on a predetermined writing method.
It is possible to have a surface structure that homogeneously aligns 8, or the surface can be
Silane compounds having a perfluorofurkyl group described in JP-A No. 36150, alkyltrialkoxysilanes described in JP-A-50-50947, tetraalkoxysilanes described in JP-A-50-63955, etc. By treating the liquid crystal composition with the compound described above, the liquid crystal composition can have a surface structure that allows 108 to be homeotropically aligned.

The optimum film thickness of the alignment control films 106 and 107 varies depending on the type of insulating material used, but is generally in the range of 100 Å to 1 μ, preferably 500 Å to 1 μ.
It is suitable to set the thickness in the range of Å to 2000 Å, and it is also desirable to set the thickness so that the alignment control films 106 and 107 also function as anti-reflection films.

Further, the liquid crystal element of the present invention forms the above-mentioned still image by irradiating the laser beam 110 from the rear direction as shown in the figure, and also receives natural light and light from the front direction.
The above-mentioned still image can be observed by making observation light 109 such as halogen lamp light, xenon lamp light, or fluorescent lamp light enter the element and using this light beam as reflected light from the cold mirror 105. This cold mirror 105 generally has sufficiently high reflectance for visible light and high transmittance for long wavelength light of 600 nm or more. Specifically, Ge/MgF ₂ (1/4λ)/CeO ₂ (1/4λ)
4λ)/Mg ₂ F ₂ (1/4λ)/CeO ₂ (1/4λ) is known. However, in the present invention, the use of cold mirror 105 can also be omitted. Further, in the device of the present invention, a cold filter (not shown) can be provided between the electrode 103 and the alignment control film 106. This cold filter has sufficiently high transmittance for visible light,
It also has sufficiently high reflectance characteristics for long wavelength light.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

Example 1 Nitrocellulose solution (manufactured by Daicel Chemical Industries, Ltd.); Ohareslucker: 12 parts by weight of a 25% by weight nitrocellulose solution in methyl ethyl ketone, 3 parts by weight of the aforementioned compound No. (30), and 70 parts by weight of methyl ethyl ketone. The parts were thoroughly mixed in a ball mill. This mixed solution was applied onto a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using a spinner coating method, and then dried to give a coating density of 0.6 g/m ^{2 .}
A recording layer was obtained.

The optical disk recording medium created in this way is mounted on a turntable, and the turntable is driven by a motor.
Spot size while giving 1000rpm rotation
5mW power and pulse width focused to 0.1 micron
Recording was carried out by scanning the surface of the recording layer with an 8 MHz gallium-aluminum-arsenic semiconductor laser (oscillation wavelength: 780 nm) in the form of a track.

When the recorded surface of the optical disc was observed using a scanning electron microscope, clear pits were observed. In addition, this optical disk has low-power gallium
When an aluminum-arsenic semiconductor laser was applied and reflected light was detected, a waveform with a sufficient S/N ratio was obtained.

In addition, in order to measure the durability stability over time after recording, the recorded recording medium was heated to 35°C.
After being left in a forced environment at ℃ and 95% relative humidity for 240 hours, the surface of the recorded recording medium was observed under a microscope in the same manner as described above, and pits similar to those observed before the durability test were observed. . Furthermore, when a low-power gallium-arsenic-aluminum semiconductor laser was incident on this recorded and durability-tested recording medium and the reflected light was detected, a waveform with a sufficiently high S/N ratio was obtained. Ta.

Example 2 The above compound No. (1) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1.
An optical disc recording medium having a recording layer of 0.6 g/m ² was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 3 The above compound No. (7) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1.
An optical disc recording medium having a recording layer of 0.6 g/m ² was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 4 The above-mentioned compound No. (11) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1.
An optical disc recording medium having a recording layer of 0.8 g/m ² was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 5 The above compound No. (12) was coated on a disc-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1.
An optical disc recording medium having a recording layer of 0.6 g/m ² was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 6 The aforementioned compound No. (16) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm by spinner coating method in the same manner as in Example 1 to form a recording layer of 0.8 g/m ² . An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 7 The above-mentioned compound No. (17) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm by spinner coating method in the same manner as in Example 1 to form a recording layer of 0.6 g/m ^{2 .} An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 8 The above-mentioned compound No. (25) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm by spinner coating method in the same manner as in Example 1 to form a recording layer of 0.8 g/m ^{2 .} An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 9 The above-mentioned compound No. (27) was coated on a disk-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm by spinner coating method in the same manner as in Example 1 to form a recording layer of 0.6 g/m ^{2 .} An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 10 The above-mentioned compound No. (37) was coated on a disc-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1 to form a recording layer of 0.8 g/m ^{2 .} An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 11 The above-mentioned compound No. (40) was coated on a disc-shaped aluminum vapor-deposited glass plate with a diameter of 30 cm using the spinner coating method in the same manner as in Example 1 to form a recording layer of 0.6 g/m ^{2 .} An optical disc recording body having the following was created.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed. Further, a durability test after recording was carried out in the same manner as in Example 1, and similar results were obtained.

Example 12 500 mg of the above compound No. (1) was placed in a molybdenum boat for vapor deposition, and after evacuated to 1×10 ^-6 mmHg or less, it was vapor deposited on an aluminum vapor-deposited glass plate. During the deposition, a 0.2 micron deposited film was formed while controlling the heater so that the pressure in the vacuum chamber did not rise above 10 ^-5 mmHg.

Example 1
When information was recorded in the same manner as in Example 1, clear pits similar to those in Example 1 were observed, and information was also reproduced in the same manner as in Example 1, but at this time, sufficient S/N ratio was not maintained. A waveform with the following characteristics was observed.

Example 13 The aforementioned compound No. (7) was vapor-deposited on an aluminum vapor-deposited glass plate in the same manner as in Example 12, and 0.2
An optical disc recording medium having a micron recording layer was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed.

Example 14 The aforementioned compound No. (26) was deposited on an aluminum-deposited glass plate in the same manner as in Example 12, and
An optical disc recording medium having a recording layer of 0.2 microns was prepared.

When information was recorded on this optical disk recording medium in the same manner as in Example 1 and then reproduced, a waveform with a sufficient S/N ratio was observed. Further, when the surface of the recording layer after information was written was observed with a scanning electron microscope, clear pits were found to have been formed.

Example 15 FIG. 5 shows an example in which a display pattern was formed using the liquid crystal element of the present invention.

Among the compounds represented by the above general formulas [], [] and [], compound No. 30 was added to a smectate liquid crystal (4,4'-cyanooctylbiphenyl; has positive dielectric anisotropy). 2% by weight
It was dissolved in a proportion of . At this time, the liquid crystal composition is heated until it becomes an isotropic phase, the above-mentioned compound is added, the liquid is injected into a cell whose inner wall surface has been subjected to a homeotropic alignment treatment, and then slowly cooled to form a homeotropic phase. A structured smectic phase liquid crystal was formed.

A laser oscillator 202 that emits a laser beam used to write an image on the liquid crystal cell 201
can be selected from wavelengths corresponding to the absorption efficiency of the above-mentioned compounds contained in the liquid crystal, but in particular long wavelength laser beams emitted from helium-neon lasers, semiconductor lasers, or YAG lasers or A short wavelength laser beam emitted by an argon laser can be used. A laser beam emitted from a laser oscillator 202 passes through a modulator 203, a slit 204, a Y-axis deflector 205, and an X-axis deflector 206, is modulated and deflected, is focused by a writing lens 208, and is focused by a dichroic mirror. The light is irradiated from the back side of the liquid crystal element 201 via the light source 209 . The aforementioned modulator 203, Y-axis deflector 205, and X-axis deflector 206
is connected to a signal source 211 via a driving amplifier 210, which controls the laser beam and converts the digital electrical signal from the signal source 211 into an optical signal. An image pattern is written on the liquid crystal element 201 by this optical signal. Thereafter, the Peltier element 212 attached to the periphery of the liquid crystal element 201 is activated by the power supply 213 to bring it into a rapid cooling state, thereby cooling the liquid crystal element 201 and forming a smectic phase of the focal conic structure, thereby generating an optical signal. An image pattern was formed in which the irradiated areas were in a light scattering state. At this time, the temperature of the Peltier element 212 is controlled by the temperature controller 214.

This image pattern can be observed by turning on the illumination source 215 placed in front of the liquid crystal element 201.

Then, to erase the aforementioned image pattern,
A transparent heater 216 (for example, an indium oxide film, a tin oxide film, an ITO film) provided on the liquid crystal element 201 is connected to a heater power source 2 via a temperature controller 217.
18 to cause a phase change from a liquid crystal phase to an isotropic phase. After that, the liquid crystal element 20
AC power supply 2 between power supplies 219 and 220 provided in 1
The liquid crystal element 201 was slowly cooled while applying a voltage from 21 to form a smectic phase having a homeotropic structure. As a result, the written image pattern was erased.

The liquid crystal element of the present invention can be applied to a large screen display, and can also be applied to an optical disk system using a recording method in which pits are formed by scanning an optical signal containing predetermined information along a track. Can be done.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of the photothermal conversion recording medium for optical disks of the present invention. FIG. 3 is an explanatory diagram showing an embodiment of the photothermal conversion recording medium.
FIG. 4 is a sectional view of the liquid crystal element of the present invention. FIG. 5 shows one of the display methods using the liquid crystal element of the present invention.
It is an explanatory diagram showing an example. 1: Substrate, 2: Thin film, 3: Reflective layer, 4: Electromagnetic radiation, 5: Pit, 101, 102: Substrate, 10
3,104: Electrode, 105: Cold mirror, 1
06,107: Orientation control film, 108: Liquid crystal composition, 109: Observation light, 110: Laser beam.

[Claims]

1. A photothermal conversion record characterized by containing an azulenium salt compound represented by the following general formula []

Claims (1)

However, in the general formulas [], [] and [], R ₁ , R ₂ , R ₃ , R ₄ and R ₅ represent a hydrogen atom, a halogen atom or a monovalent organic residue, and X is substituted or unsubstituted. Represents a group of atoms necessary to form a substituted 5-, 6-, or 7-membered aromatic ring. Also, R ₁
and an aromatic ring formed by X, a combination of an aromatic ring formed by X and _R2 , _R2 and _R3 , _R3 and _R4 , and _R4 and _R5 , at least A single combination may form a ring of substituted or unsubstituted aromatic rings, heterocycles, or aliphatic chains. A represents a divalent organic residue bonded via a double bond.
Z represents an anionic residue. 2. Claim 1, wherein the azulenium salt compound is contained in a coating formed on a substrate.
The photothermal conversion recording medium described in . 3. The photothermal conversion recording medium according to claim 1, wherein the azulenium salt compound is contained in a liquid crystal. 4. The photothermal conversion recording medium according to claim 3, wherein the liquid crystal is a smectic liquid crystal.