JPS63223066A - Information recording medium - Google Patents

Abstract

PURPOSE:To obtain an information recording medium comprising a thermally stable dyestuff having absorption in a long wavelength range, causing no deterioration of recording characteristics even by repetition of recording and erasing, having a recording layer made of a high polymer liquid crystal between a pair of substrates, containing a specific organic dyestuff. CONSTITUTION:In an information recording medium having a recording layer made of high polymer liquid crystal between a pair of substrates, one or more organic dyestuffs shown by formula I (R1-R4 are H or hydrocarbon; r1 and r2 are H or hydrocarbon; a is 0 or 1; b is 0-2; X<-> is anion), formula II (R5-R8 are H or hydrocarbon; r3'-r7' are H, halogen or hydrocarbon; Y1 is bifunctional group; c and d are 0-2), formula III (R13-R16 are H or hydrocarbon; r11'-r14' are H or hydrocarbon; Z<-> is group shown by formula IV; e and f are 0-2), formula V (R17-R23 are H or hydrocarbon; F1 is bifunctional residue) and formula VI (L1 and L2 are S or O; Z1 is pyrylium skeleton component-forming atom group; Z2 is pyran skeleton-forming atom group; r15-r21 are H or hydrocarbon; g and i are 0 or 1; h is 0-2) to give the aimed recording medium.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an information recording medium having a liquid crystal layer.

[Prior art]

In recent years, rewritable recording media have been actively developed. One known example is one that utilizes phase transitions in liquid crystals.

For example, an oriented liquid crystal layer sandwiched between a pair of transparent electrodes or suitable substrates is optically transparent. Therefore, when the temperature of this liquid crystal layer is raised to exceed the phase transition temperature (nematic phase to liquid phase, or smectic phase to nematic phase) and then rapidly cooled, the liquid crystal layer does not return to its original transparent state but exhibits a light scattering state. In other words, recording and reading are performed based on this contrast difference.

Furthermore, after writing, apply an electric field between the electrodes of the medium, or
Alternatively, by heating and slow cooling, the transition to the original smectic phase or the like can be performed and eliminated.

In addition, erasing can be performed by heating while applying a voltage, or by heating without applying a voltage. Recently, polymer liquid crystals that have a glass transition temperature and excellent memory properties have been attracting attention.

Normally, a small and low-cost semiconductor laser is often used to heat the polymer liquid crystal layer, but the oscillation wavelength of this laser is usually 700 nm or more, and argon laser, helium neon laser, etc. Laser light power is low compared to gas lasers. Since normal liquid crystals do not absorb in such long wavelength ranges, it is known to contain light-absorbing dyes in liquid crystals.

However, dyes that generally absorb in the long wavelength range are not sufficiently thermally stable in liquid crystals, and when writing and erasing are repeated, they partially decompose, resulting in the problem that sufficient contrast cannot be obtained.

〔the purpose〕

Therefore, an object of the present invention is to provide an information recording medium that has absorption characteristics in the near-infrared wavelength region, is stable when dissolved or dispersed in liquid crystal, and does not deteriorate its recording characteristics even after repeated writing and erasing. It is in.

[Means and actions to achieve the purpose]

It has been found that this object of the present invention can be achieved by incorporating the following organic dye into the polymeric liquid crystal.

A polymethine dye represented by general formula (1).

(In the formula, J+ R2+ R3 and R4 are hydrogen atoms, alkyl groups, alkenyl groups, substituted or unsubstituted aralkyl groups, substituted or unsubstituted aryl groups, styryl,
Indicates substituted styryl or heterocycle or substituted heterocycle. r
l and r2 are hydrogen atoms, alkyl groups, cyclic alkyl groups,
Represents an alkenyl group, aralkyl group, styryl, substituted styryl, substituted aralkyl or aryl group, a is 0 or °
1, b is 0. 1 or 2, Xe means an anion. ) A dye represented by general formula (If).

(In the formula, R5+ R6+ R7 and R8 represent a hydrogen atom, an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a styryl, a substituted styryl, a heterocycle, or a substituted heterocycle.1'
3 to r/ represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Y represents a divalent residue having the atomic group necessary to complete a 5- or 6-membered ring. xe means anion.

c, d is 0. 1 or 2. ) A dye represented by general formula (III).

(In the formula, R9+ RIG + R11 and RI2 represent a hydrogen atom, an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, styryl, substituted styryl, a heterocycle, or a substituted heterocycle. /8~r/, represents a hydrogen atom, a 710gen atom, an alkyl group, or an aryl group.Y2 is a 5-membered ring or a 6-membered ring.
Indicates a divalent residue having the necessary atomic groups to complete the membered ring. Xe means an anion. ) A dye represented by general formula (IV).

(In the formula, J3 + R14+ R16 and RI6 represent a hydrogen atom, an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a styryl, a substituted styryl, a heterocycle, or a substituted heterocycle. r '11 to r'0. represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group.

e, f are 0. 1 or 2. Xe means an anion.

Furthermore, it has been found that a small amount (or one kind) of the azulenium dyes represented by the general formula (V), (VI), or (Vn) may be contained.

2s (Here, R17 to R37 are hydrogen atoms, halogen atoms (
chlorine atom, bromine atom, iodine atom) or a monovalent organic residue. Monovalent organic residues can be selected from a wide variety.

Also, in general formula (V), R17 and R1111
RI8 and R19* R19 and R20* R20 and R
21r At least one combination of R21 and R22 and R22 and R23 may form a substituted or unsubstituted fused ring. The fused ring is 5-membered, 6-membered,
or a 7-membered condensed ring, including aromatic rings (benzene, naphthalene, chlorobenzene, bromobenzene, methylbenzene, ethylbenzene, methoxybenzene, ethoxybenzene, etc.), heterocycles (furan ring, benzofuran ring,
Pyrrole ring, thiophene ring, pyridine ring, quinoline ring,
thiazole rings, etc.) aliphatic rings (dimethylene, trimethylene, tetonamethylene, etc.). This also applies to general formulas (VI) and (vn).

General formula (vr) If you like, R24 and R251R
25 and R28+ R2g and R27+ R27 and R211
A substituted or unsubstituted condensed ring may be formed by at least one combination of 1R and R29 and R and R and o.

If general formula (VII) is followed, R31 and R32+
R112 and R33, R, and R34* R34 and R35
At least one combination of T RIs and R38 and R38 and R may form a substituted or unsubstituted fused ring.

Xe means an anion.

Further, in the general formula (V), F represents a divalent organic residue bonded via a double bond. Specific examples of the present invention containing such F include those represented by the following general formulas (1) to (11). However, Qe in the formula represents the following azulenium ring nucleus, and the right side excluding Qe in the formula represents Fl.

General formula % formula % (In the formulas (1) to (12) above, R' 17 to R'23 and R17 to R23 are R17 to R
Similar to 23, it represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, an amino group, a styryl group, a nitro group, a hydroxy group, a carboxy group, a cyano group, or an arylazo group, and R' 17 to R' 23 and R
′! 7 to R'23 may form a substituted or unsubstituted condensed ring similarly to RI7 to R23. n is 0. l or 2, r represents an integer from 1 to 8, S represents O or l, and t represents l or 2.

M2 represents a group of nonmetallic atoms necessary to complete the nitrogen-containing heterocycle.

R39 represents 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.). R
40 is an alkyl group (methyl, ethyl, propyl, butyl, etc.), a substituted alkyl group, (2-hydroxyethyl, 2
-methoxyethyl, 2-ethoxyethyl, 3-hydroxypropyl, 3-methoxypropyl, 3-ethoxypropyl, 3-chloropropyl, 3-bromopropyl, 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 group (
phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl) or substituted aryl groups (chlorophenyl, dichlorophenyl, trichlorophenyl, ethylphenyl, methoxyphenyl, dimethoxyphenyl, aminophenyl,
(nitrophenyl, hydroxyphenyl, etc.).

R41 represents a substituted or unsubstituted aryl group or a cation group thereof; specifically, R41 represents a substituted or unsubstituted aryl group (phenyl, tolyl, xylyl, biphenyl, α-naphthyl, β-naphthyl, anthralyl,
Pyrenyl, methoxyphenyl, dimethoxyphenyl, trimethoxyphenyl, ethoxyphenyl, jetoxyphenyl, chlorophenyl, dichlorophenyl, trichlorophenyl, bromophenyl, dibromophanyl, tribromophenyl, ethylphenyl, diethylphenyl,
Nitrophenyl, aminophemyl, dimethylaminophenyl, diethylaminophenyl, dibenzylaminophenyl, dipropylaminophenyl, morpholinophenyl, piperidinylphenyl, piperazinophenyl, diphenylaminophenyl, acetylnaminophenyl, benzoylaminophenyl, acetylphenyl, benzoylphenyl, cyanophenyl, etc.).

R4゜ represents a heterocyclic group or a cationic group thereof; more specifically, R4□ represents a monovalent group derived from a heterocyclic group such as furan, thiophene, benzofuran, thionaphthene, dibenzofuran, carbazole, phenothiazine, phenoxazine, and pyridine. represents a heterocyclic group.

R43 is a hydrogen atom, an alkyl group (methyl, ethyl, propyl, butyl, etc.) or a substituted or unsubstituted aryl group, (phenyl, tolyl, xylyl, biphenyl, ethylphenyl, chlorophenyl, methoxyphenyl, ethoxyphenyl, nitrophenyl, amino phenyl, dimethylaminophenyl, diethylaminophenyl, acetylaminophenyl, α-naphthyl, β-naphthyl, anthralyl, pyrenyl, etc.).

In the formula, z7 is an atomic group necessary to complete the optionally substituted pyran, thiapyran, selenaviran, telluropyran, benzobilane, benzothiapyran, benzoselenapyran, benzotelluropyran, naphthopyran, naphthothiapyran, naphthoselenapyran, or naphthotellopyran. show.

R7 represents a sulfur atom, an oxygen atom, a selenium atom or a tellurium atom.

R44 and R46 represent a hydrogen atom, an alkoxyl group, a substituted or unsubstituted aryl group, an aralkenyl group, or a heterocyclic group.

More specifically, R44 and R45 are hydrogen atoms, alkyl groups (methyl, ethyl, propyl, butyl, etc.), alkoxyl groups (methoxy, ethoxy, propoxy, ethoxyethyl, methoxyethyl, etc.), aryl groups (phenyl,
tolyl, xylyl, chlorophenyl, biphenyl, methoxyphenyl, etc.), substituted or unsubstituted skyryl group (skyryl, p-methylskiryl, 0-chlorostyryl, p-methoxystyryl, etc.), substituted or unsubstituted thiophenyl, 1,3- Butadienyl group (4-phenyl, 1,3-butadienyl, 4-(p-medelphenyl)
, 1, 3-butadiyl, etc.), or a substituted or unsubstituted heterocyclic group (quinolyl, pyridyl, carbazolyl, furyl, etc.).

The same can be said for F2 and F3 in general formulas VI and v■.

However, in that case, the code R'-R' represented by Fl
30 are respectively R' 17 to R' 23 and R' 24 to
R' ao corresponds to R' 17 to R', respectively, and regarding F3, R' Xi to R' 37 respectively correspond to R' 17 to R' 23, and R'3o=R' 3
7 correspond to R' t7 to R' 23, respectively.

In addition, as a suitable dye, the general formula (Vllll) (IX)
It has been found that at least one of the dyes represented by (X) and (XI) may be selected.

Xe (In the above formula, LL+ L2 represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, Zl is an atomic group necessary to form a biryllium-based skeleton that may be substituted, and Z2 is an optionally substituted Shows the atomic groups necessary to form a pyran skeleton.

r15 to r2+ mean a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, g and i are 0 or l, and h is 0.
Indicates 1 or 2. Xe represents an anion. )Xe (In the above formula, L3 is a sulfur atom, an oxygen atom, a selenium atom,
Alternatively, Z3 represents a tellurium atom, an atomic group necessary to form a good biryllium-based skeleton, and Z3 represents an atomic group necessary to form a pyran-based skeleton, which may be substituted. Ml is a group of nonmetallic atoms sufficient to form a nitrogen-containing heterocycle.

j and l represent O or l, and k represents 0.1 or 2.

rn to r24 mean a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and r' means a hydrogen atom, a halogen atom,
Indicates an alkyl group or an aryl group. F3 is a 5-membered ring or a 6-membered ring
It represents a divalent residue having the atomic group necessary to complete a membered ring, and Xe represents an anion. ) (In the above formula, L4.L
, represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, Z4 is an atomic group necessary to form a biryllium-based skeleton that may be substituted, and Z5 is an atomic group necessary to form a pyran-based skeleton that may be substituted. Indicate the required atomic groups.

r, to r2g mean a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and m and 0 represent 0 or 1.

(In the above formula, L6 is a sulfur atom, an oxygen atom, a selenium atom,
Alternatively, it represents a tellurium atom, and Z6 represents an atomic group necessary to form a biryllium-based skeleton that may be substituted.

F30-F33 means a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and r3B represents an aryl group or a substituted or unsubstituted heterocyclic group.

p represents 0 or l, q represents 0. Indicates 1 or 2.

Xe represents an anion. ) (However, the above general formula (Vnl) (IX) (X) (
In XI), the atomic group necessary to form the optionally substituted pyrylium skeleton of Z is pyrylium, thiopyrylium, selenapyrylium, telluropyryllium, benzopyrylium, benzothiopyryllium, which may be substituted. ,
It can also be said to be an atomic group necessary to complete benzoselenopyrylium, benzotelluropyryllium, naphthopyryllium, naphthothiopyrylium, naphthoselenapyrylium, or naphthotellopyrylium, and may also be substituted for Z2. Forming a bilane-based skeleton means completing a biran, thionpyran, selenapyran, telluropyran, benzobilane, benzothiopyran, benzoselenapyran, benzotelluropyran, naphthopyran, naphthothiopyran, naphthoselenaviran, or naphthotellopyran, which may be substituted. It is the meaning. ) Furthermore, the abbreviations in the above general formulas (I) to (XI) will be described in detail.

R1 to RI6 are hydrogen atoms or alkyl groups (e.g., methyl group, ethyl group, n-propyl group, 1SO-propyl group, n-butyl group, 5ec-butyl group, iso-butyl group, t-butyl group, n -amyl group, t-amyl group, n
-hexyl group, n-octyl group, t-octyl group, etc.)
and further includes other alkyl groups, such as substituted alkyl groups (e.g., 2-hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3
-Sulfopropyl group, 4-sulfoethyl group, 3-sulfatepropyl group, 4-sulfatebutyl group, N
-(methylsulfonyl)-carbamylmethyl group, 3-(
acetylsulfamyl)propyl group, 4-(acetylsulfamyl)butyl group, etc.), cyclic alkyl group (e.g., cyclohexyl group, etc.), allyl group (CH2=CH-
CH2-), alkenyl group (vinyl group, propenyl group,
butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, dodecynyl group, prenyl group, etc.),
Aralkyl groups (e.g. benzyl group, phenethyl group, α
-naphthylmethyl group, β-naphthylmethyl group, etc.), and substituted aralkyl groups (eg, carboxybenzyl group, sulfobenzyl group, hydroxybenzyl group, etc.).

Furthermore, substituted or unsubstituted aryl groups (e.g., phenyl group, naphthyl group, tolyl group, xylyl group, methoxyphenyl group, dimethoxyphenyl group, trimethoxyphenyl group, ethoxyphenyl group, dimethylaminophenyl group, diethylaminophenyl group, dipropylaminophenyl group, dibenzylaminophenyl group, diphenylaminophenyl group), substituted or unsubstituted heterocyclic groups (e.g. pyridyl group, quinolyl group, lepidyl group, methylpyridyl group, furyl group, chenyl group, indolyl group) basis,
pyrrole group, carbazolyl group, N-ethylcarbazolyl group) or substituted or unsubstituted styryl group (e.g. styryl group, methoxystyryl group, dimethoxystyryl group, trimethoxystyryl group, ethoxystyryl group,
Dimethylaminostyryl group, diethylaminostyryl group, dipropylaminostyryl group, dibenzylaminostyryl group, diphenylaminostyryl group, 2,2-diphenylvinyl group, 2-phenyl-2-methylvinyl group, 2
-(dimethylaminophenyl)-2-phenylvinyl group, 2-(diethylaminophenyl)-2-phenylvinyl group, 2-(dibenzylaminophenyl)-2-phenylvinyl group, 2,2-di(diethylaminophenyl) Vinyl group, 2,2-di(methoxyphenyl)vinyl group, 2
．． 2-di(ethoxyphenyl)vinyl group, 2-(dimethylaminophenyl)-2-methylvinyl group, 2-(diethylaminophenyl)-2-ethylvinyl group, etc.).

rl + r2 * rl5~r21 + r22~
"24 + r26 to r29 and rl0 to r33 are hydrogen atoms or alkyl groups (e.g., methyl group, ethyl group, n
-propyl group, 1so-propyl group, n-butyl group, 5
ec-butyl group, 1so-butyl group, t-butyl group, n
-amyl group, t-amyl group, n-hexyl group, n-octyl group, t-octyl group, etc.), and further shows other alkyl groups, such as substituted alkyl groups (e.g. 2-hydroxyethyl group, 3-hydroxypropyl group). group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group, 4-
Sulfobutyl group, 3-sulfatepropyl group, 4-sulfatebutyl group, 4-sulfatebutyl group, N-
(methylsulfonyl)-rubamylmethyl group, 3-(acetylsulfamyl)propyl group, 4-(acetylsulfamyl)butyl group, etc.), cyclic alkyl group (e.g.
cyclohexyl group, etc.), allyl group (CH2=CH-C
H2-), alkenyl groups (vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, dodecynyl group, prenyl group, etc.), aralkyl group (e.g. benzyl group, phenethyl group, α-
naphthylmethyl group, β-naphthylmethyl group, etc.), and substituted aralyl groups (eg, carboxybenzyl group, sulfobenzyl group, hydroxybenzyl group, etc.).

r'3~""I+"8~r/, and r'1.~r'1
4 is hydrogen atom, halogen atom (chlorine atom, bromine atom, iodine atom, etc.) alkyl group (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), substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, ethylphenyl, methoxyphenyl, ethoxyphenyl,
chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.). Y1
~Y3 is a divalent hydrocarbon group, for example -CH2-CH2-
.

The 5-membered ring or 6-membered ring may be fused with a benzene ring, a naphthalene ring, etc.

R, F~R23, R24~R3o and R31~Rn are hydrogen atoms, halogen atoms (chlorine atom, bromine atom, iodine atom, etc.) and 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, etc.), , xylyl, ethylphenyl, methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenyl- 1-methylethyl, bromobenzyl,
2-bromophenylethyl, 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, Mention may be made of hydroxy groups, carboxyl groups, cyano groups, or substituted or unsubstituted arylazo groups (phenylazo, α-naphthylazo, β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo, tolylazo, etc.) .

M is pyridine, thiazole, benzothiazole, naphthothiazole, oxazole, benzoxazole, naphthoxazole, imidazole, benzimidazole, naphthimidazole, 2-quinoline, 4-quinoline,
A group of atoms necessary to complete a nitrogen-containing heterocycle such as isoquinoline or indole, including halogen atoms (chlorine, bromine, iodine, etc.), alkyl groups (methyl, ethyl, propyl, butyl, etc.), aryl groups (phenyl), etc. , tolyl, xylyl, etc.) may be substituted by aralkyl (benzyl, p-tolylmethyl, etc.).

Xe is an anion such as chloride ion, bromide ion, iodide ion, perchlorate ion, benzenesulfonate ion, p-toluenesulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion,
Tetrafluoroborate ion, tetraphenylborate ion, hexafluorophosphate ion, benzenesulfinate ion, acetate ion, trifluoroacetate ion, propionacetate ion, benzoate ion, oxalate ion, succinate ion, malonate ion, oleate ion, stearate ion, citrate ion, -hydrogen diphosphate ion, dihydrogen-phosphate ion, pentachlorostannate ion, Chlorosulfonate ion, fluorosulfonate ion, l-
Represents refluoromethanesulfonate ion, hexafluoroantimonate ion, molybdate ion, tungstate ion, titanate ion, zirconate ion, etc.

Next, specific examples of organic dyes used in the present invention are listed in Table 1, but the invention is not limited thereto.

The time is expressed as zeb.

Further, for convenience, the abbreviations of the compounds in the table are shown below.

C2H4oCH3 In addition, the structures of YI + Y2, Y3 and Ml are abbreviated as follows.

-(CH2) 2- = yl -(CH2)
3- = y2H3 CH=CH- The above dye has absorption in the infrared region, is useful as a stable light-absorbing dye, and has good compatibility with the medium. Some dyes in the text have dichroism, and if these dichroic dyes are dissolved in a polymer liquid crystal, a thermally stable host can be created.
Guest-based memory and display media can also be obtained.

Further, the polymer liquid crystal may contain two or more types of dyes.

The amount of dye added to the liquid crystal is 0.01% by weight.
% to 5% is preferable. The liquid crystal used in the present invention is a polymeric thermotropic liquid crystal, and uses a nematic, smectic, or cholesteric phase as an intermediate phase.

The primary basic structures of polymer thermotropic liquid crystals that can be used in the present invention are classified into the following two types.

■ Mesogenic groups or relatively rigid and long atomic groups connected by flexible chains.

■ Those with mesogen groups or relatively rigid and long atomic groups in their side chains.

Ferroelectric polymer liquid crystals having chiral asymmetric carbons can also be used, and it has been confirmed that the compatibility of the dyes with those shown in the present invention is good.

Specific examples of these polymeric thermotropic liquid crystals are shown in Table 1.

Table 1 Q O CH3 o o o.

e "Polymer liquid crystals can be used in combination with several different types of polymer liquid crystals. It is also possible to use them as a mixture of polymer liquid crystals and low-molecular liquid crystals, in which case the weight ratio is higher than that of polymer liquid crystals. The ratio of low-molecular liquid crystal to 1 of liquid crystal is preferably 10 or less.

In the polymeric liquid crystal, if necessary, ordinary polymers (for example, olefin resin, acrylic resin, polystyrene resin, polyester resin, polyurethane resin, polycarbonate resin, etc.), oligomers, various plasticizers, various stabilizers, A quencher or the like may be contained. Thin films of polymer liquid crystals can be made by dissolving the polymer liquid crystal in a solvent, coating the substrate with spin cord or dip coating, and drying it, or by sandwiching the polymer liquid crystal between substrates and molding it under heat and pressure. It may also be used after being made into a film.

Note that the thickness of the liquid crystal layer is approximately 0.01 to 100 μm.

Furthermore, generally known methods can be used to uniformly orient the polymer liquid crystal in a certain direction.

For example, as the orientation method, a rubbing method, an oblique evaporation method, a method of applying shear stress by sandwiching between two substrates, a method of causing a slow phase transition while applying a magnetic field, a method of orientation using a spacer edge, etc. can be used.

Further, FIGS. 1 and 2 are cross-sectional views of one embodiment of the information recording medium of the present invention. In FIG. 1, reference numeral 1 represents a substrate, 2 represents an alignment film, 3 represents a recording layer of the present invention, and 4 represents a reflective layer.

Further, in FIG. 2, the symbols 1, 2 and 3 are the same as the symbols in FIG. Reference numeral 5 indicates a transparent electrode, and 6 indicates an electrode/reflection layer. FIG. 3 shows a schematic diagram of an apparatus that performs writing and reading by irradiating a recording medium with a laser.

For writing, the laser beam emitted from the laser oscillator 8 is sent to the optical system 1.
1 and enters the recording medium.

For reading, the laser beam emitted from the laser oscillator 8 is sent to the optical system 1.
1 and a beam splitter 7 to a recording medium, and using the reflected light, the light passes through the beam splitter again and is read by a photodetector 9.

The present invention will be explained in more detail below based on Examples.

<Example 1> A polyamic acid solution (PI manufactured by Hitachi Chemical Co., Ltd.
Q) was applied, heated, and then rubbed and treated to provide a polyimide alignment film.

On top of this, the following side-chain polymer liquid crystals and dyes (No. in Table 1,
5) in 1.1.2-)lichloroethane,
After coating and drying by a spinner method, a polymer liquid crystal film having a thickness of 3 μm was formed. The amount of dye added is 0.
It is 1wt%.

Furthermore, on top of this polymeric liquid crystal layer, a spacer (thickness: 3 μm) was placed around the outer periphery, and a polyimide alignment film was attached in the same manner as described above on a glass substrate on which a reflective film (aluminum vapor deposited film) was formed. Superimposed.

A part of its cross-sectional configuration is shown in FIG. 9 of the above laminates
By heating to 0° C. and slowly cooling, the liquid crystal layer was made into a nematic layer state, and an information recording medium was produced.

When this recording medium was irradiated from the transparent substrate side with an 830 nm semiconductor laser 8 at a recording power of 2.0 mW, the orientation of the irradiated area was disturbed and a scattering state occurred. . Next, read power 0.2m
W was used for reproduction, and the signal intensity of the reproduced light was measured by the photodetector 9 (B→signal intensity of the recording section) was calculated.

Further, the substrate on which recording was performed was heated to 90° C. and slowly cooled, and erasing was performed by aligning the recorded portion.

Furthermore, recording and erasing were repeated, and after 300 repetitions, the data was reproduced and the contrast ratio was measured.

<Examples 2 to 10> Information recording media were produced in the same manner as in Example 1 except that the dyes shown in the table below were used as the dyes soluble in the polymeric liquid crystal.

The contrast ratio was also measured in the same manner.

Comparative Example 1 An information recording medium was produced in the same manner as in Example 1, except that the dye shown below was used as the dye dissolved in the polymer liquid crystal. However, the pigment content is 0.1wt% based on the polymer.
It is.

<Example 11> A 500 mm square on which ITO was deposited as a transparent electrode layer.

Thickness 1. ．． A polyamic acid solution (PIQ, manufactured by Hitachi Chemical Co., Ltd.) was applied onto a 2 mm glass substrate, heated, and then rubbed to form a polyimide alignment film.

On top of this, the ferroelectric polymer liquid crystal shown below and the dye (N
5) was dissolved in 1.1.2-trichloroethane, applied by a spinner method, and dried to form a liquid crystal layer with a thickness of 3 μm.

H3 glass 20~30℃8mc*73-75'CSm
A 83-85'CIs.

(Y is 20) As in Example 1, a substrate on which a polyimide alignment film was attached in the same manner as described above was superimposed on a glass substrate on which an electrode layer/reflection layer (aluminum evaporated film) was formed, with spacers separated. Ta.

A part of its cross-sectional configuration is shown in FIG.

The above-mentioned laminate is heated to 90° C. and then slowly cooled to bring the liquid crystal layer into a uniaxially oriented smectic phase state, and a voltage is applied between the electrodes to align the polarization direction in a certain direction to form an information recording medium. Created. In this recording medium, a recording power of 1 was applied using an 830 mm semiconductor laser while applying a reverse electric field between the transparent electrode (ITO) and the A1 electrode.
, 5 mW was applied to the recording section from the transparent electrode side to heat it, and the direction of the spontaneous polarization was reversed, thereby writing the recording.

Next, without applying an electric field, a laser beam is irradiated with polarized light at a reproduction output of 0.15 mW, and since the reflected light contains a difference in birefringence due to the difference in the direction of polarization, it enters the photodetector. The light intensity was measured and the contrast ratio was calculated.

Further, while applying a forward electric field between the ITO and An electrodes again, irradiation was performed with a laser power of 1.8 mW to erase the recorded portion or the entire surface.

After repeating recording and erasing 300 times, the data was reproduced and the contrast ratio was measured.

Examples 12 to 16 Information recording media were produced in the same manner as in Example 11, except that the dyes shown in the table below were used as the dyes dissolved in the ferroelectric polymer liquid crystal.

<Comparative Example 2> An information recording medium was produced in exactly the same manner as in Example 11, except that the organic dye and the dye used in Comparative Example 1 were used. The above results are summarized in Table 2.

Table 2 [Effects of the Invention] In the information recording medium of the present invention configured as described above, the dye contained in the polymeric liquid crystal that absorbs in the long wavelength range is thermally stable and recording and erasing is difficult. Even if the recording is repeated, the contrast ratio of the recording will not decrease.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are cross-sectional views of the information recording medium of the present invention. Figure 3 is a schematic diagram of the optical system for recording, reproducing, and erasing.8...Semiconductor laser

Claims (2)

[Claims] (1) An information recording medium having a recording layer made of polymer liquid crystal between a pair of substrates, the recording layer having the following general formula (
An information recording medium comprising at least one kind of organic dyes represented by I) to (XI). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1, R_2, R_3 and R_4 are hydrogen atoms,
It represents an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a styryl, a substituted styryl, a heterocycle or a substituted heterocycle. r_1 and r_2 represent a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a styryl, a substituted styryl, a substituted aralkyl, or an aryl group, and a is 0
Or 1, b is 0, 1 or 2, and X^■ means an anion. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, R_5, R_6, R_7 and R_8 are hydrogen atoms,
It represents an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a styryl, a substituted styryl, a heterocycle or a substituted heterocycle. r_3' to r_7' represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Y_1 represents a divalent residue having the atomic group necessary to complete a 5-membered ring or a 6-membered ring. X^■ means anion. c and d are 0, 1 or 2. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) (In the formula, R_9, R_1_0, R_1_1 and R_1_2
represents a hydrogen atom, an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, styryl, substituted styryl, heterocycle or substituted heterocycle. r_8' to r_1_0' represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Y_2
represents a divalent residue having the atomic group necessary to complete a 5- or 6-membered ring. X^■ means anion. )▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) (In the formula, R_1_3, R_1_4, R_1_5 and R_1
_6 represents a hydrogen atom, an alkyl group, an alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, styryl, substituted styryl, a heterocycle, or a substituted heterocycle. r_1_1' to r_1_4' represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Z^■ indicates ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼. e and f are 0, 1 or 2. X^■ means anion. ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (V) (In the formula, R_1_7 to R_2_3 are hydrogen atoms, halogen atoms, alkyl groups, aryl groups, aralkyl groups, amino groups, styryl groups, nitro groups, hydroxy groups, carboxyl groups , cyano group, or arylazo group, R_1_7
~R_2_3 may be combined to form a substituted or unsubstituted condensed ring. F_1 represents a divalent organic residue. X^■ indicates an anion. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(VI) (In the formula, R_2_4 to R_3_0 are hydrogen atoms, halogen atoms, alkyl groups, aryl groups, aralkyl groups, amino groups, styryl groups, nitro groups, hydroxy groups, carboxyl groups, Indicates a cyano group or an arylazo group, R_1_7
~R_2_3 may be combined to form a substituted or unsubstituted condensed ring. F_2 represents a divalent organic residue. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(VII) (In the formula, R_3_1 to R_3_7 are hydrogen atoms, halogen atoms, alkyl groups, aryl groups, substituted or unsubstituted aralkyl groups, substituted or unsubstituted amino groups, substituted or represents an unsubstituted styryl group, nitro group, hydroxy group, carboxyl group, cyano group, or arylazo group,
R_3_1 to R_3_7 may be combined to form a substituted or unsubstituted condensed ring. F_3 represents a divalent organic residue. X^■ indicates an anion. ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (VIII) (In the above formula, L_1 and L_2 represent a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Z_1 forms a pyrylium-based skeleton that may be substituted. The atomic group required for, Z_
2 represents an atomic group necessary to form a pyran skeleton which may be substituted. r_1_5 to r_2_1 mean a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, g and i are 0 or 1,
indicates 0, 1 or 2. X^■ indicates an anion. )
▲There are mathematical formulas, chemical formulas, tables, etc.▼(IX) (In the above formula, L_3 is a sulfur atom, an oxygen atom, a selenium atom,
Alternatively, Z_3 represents a tellurium atom, an atomic group necessary to form a good pyrylium-based skeleton, and Z_3 represents an atomic group necessary to form a pyran-based skeleton, which may be substituted. M_1 is a group of nonmetallic atoms sufficient to form a nitrogen-containing heterocycle. j and l represent 0 or 1, and k represents 0, 1 or 2. r_2_2 to r_2_4 represent a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and r_2_5' represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. y_3 represents a divalent residue having an atomic group necessary to complete a 5-membered ring or a 6-membered ring, and X^■ represents an anion. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(X) (In the above formula, L_4 and L_5 represent a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Z_4 forms a pyrylium-based skeleton that may be substituted. The atomic group required for, Z_
5 represents an atomic group necessary to form a pyran skeleton which may be substituted. r_2_6 to r_2_9 mean a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and m and o represent 0 or 1. Z^■ indicates ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(X I) (In the above formula, L_6 is a sulfur atom, an oxygen atom, a selenium atom,
or a tellurium atom, and Z_6 represents an atomic group necessary to form a pyrylium-based skeleton that may be substituted. r_3_0 to r_3_3 represent a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group, a substituted aralkyl group, or an aryl group, and R_3_8 represents an aryl group or a substituted or unsubstituted heterocyclic group. p represents 0 or 1, and q represents 0, 1 or 2. X^■ indicates an anion. ) (2) The information recording medium according to claim 1, wherein the polymer liquid crystal is a ferroelectric polymer liquid crystal.