JP2696697B2

JP2696697B2 - Information recording medium

Info

Publication number: JP2696697B2
Application number: JP62195186A
Authority: JP
Inventors: 健宮崎; 芳弘小口; 和夫吉永; 敏一大西
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1987-08-06
Filing date: 1987-08-06
Publication date: 1998-01-14
Anticipated expiration: 2013-01-14
Also published as: JPS6440379A

Description

【発明の詳細な説明】［産業上の利用分野］本発明は高分子液晶を含有する記録層を有する情報記
録媒体に関する。［従来の技術］近年、大容量メモリーやディスプレー等の用途として
の書き換え可能な記録媒体の開発が活発に行われてい
る。その１つに液晶の相転位を利用したものが知られて
いる。例えば、１対の透明電極あるいは、適当な基板によっ
てサンドイッチされた配向状態を保っている液晶層は光
学的に透明である。そこで、この液晶層の温度を上げ、
相転移温度（ネマティック相→液相、またはスメクティ
ック相→ネマティック相）以上にし、急冷すると液晶層
はもとの透明状態に戻らず光散乱状態を示す。つまり、
このコントラスト差により、記録、読み出しを行うもの
である。さらに書き込み後、記録媒体の電極間に電場を印加す
るか、あるいは加熱・徐冷することによりもとのスメク
チック相等への転移が行われ、消去できる。その他に、電圧を印加しながら、加熱を行ったり、電
圧を印加しないで加熱して消去を行うこともできる。ま
た最近、ガラス転移点をもち、メモリー性の優れた高分
子液晶が注目されてきた。通常、高分子液晶層の加熱には、小型でしかも低コス
トな半導体レーザを利用することが多いが、このレーザ
の発振波長は通常650nm以上であり、又一般にアルゴン
レーザ、ヘリウム・ネオンレーザなどのガスレーザに比
べレーザ光パワーが小さい。通常の液晶は、そのような
近赤外域に吸収がないため、液晶中に光吸収性色素を含
有させることが知られている。しかし一般に近赤外域に吸収をもつ色素は、液晶中で
熱的に十分に安定でなく、書き込み消去を繰返すと一部
分解し、十分なコントラストが得られなくなるという問
題があった。［発明が解決しようとする問題点］本発明は、上記の様な従来技術の問題を解決するため
になされたものであり、近赤外域の波長に吸収特性をも
ち、かつ液晶中に溶解または分散された状態で安定で、
書き込み消去を繰返しても、記録特性が劣化しない情報
記録媒体を提供することを目的とするものである。［問題点を解決するための手段］および［作用］本発明のかかる目的は、本発明者等の研究の結果、高
分子液晶中に下記に示す少なくとも１種の近赤外吸収化
合物を含有させることで達成することが判明した。即ち、本発明は、高分子液晶を含有する記録層を有す
る情報記録媒体であって、該記録層中に下記の一般式
［１］乃至［10］で表わされる化合物から選ばれた少な
くとも１種が溶解もしくは分散されていることを特徴と
する情報記録媒体である。一般式［１］（式中、R₂₇はイオウ原子、置換ないし非置換のアミノ
基、酸素原子又はチオケトン基、R₂₈は水素原子、アル
キル基、ハロゲン原子又はアミノ基を表わし、ＭはZn,C
u又はNiを表わす。）一般式［２］（式中、R₂₉はアルキル基、アリール基又はスチリル基
を表わし、ＭはCu,Ni,又はCoを表わす。）一般式［３］（式中、R₃₀は水素原子、ハロゲン原子、アルキル基、
アシル基又はアリール基を表わし、ＭはNi又はZrを表わ
す。）一般式［４］（式中、R₃₁はアルキル基又はアリール基、ＭはCu,Ni又
はCoを表わす。）一般式［５］（式中、R₃₂,R₃₃はアルキル基又はアリール基、ＭはNi
を表わす。）一般式［６］（式中、R₃₄,R₃₅はアルキル基、アミノ基、アリール基
又はフラン基、又はR₃₄とR₃₅で脂環式化合物を形成して
も良い。ＭはNiを表わす。）一般式［７］（式中、R₃₆,R₃₇は水素原子、ハロゲン原子又はアルキ
ル基でＸは酸素原子又は硫黄原子、ＭはNiを表わす。）一般式［８］（式中、R₃₈,R₃₉は水素原子、アルキル基、ハロゲン原
子又はニトロ基、Ｘは酸素原子又は硫黄原子、ＭはNi、
Ｙは４級アンモニウムカチオンを表わす。）一般式［９］（式中、R₄₀はアミノ基、ＭはCu,Ni,Co又はPdを表わ
す。）一般式［10］（式中、R₄₁は水素原子、ハロゲン原子、アルキル基、
アシル基、ニトロ基又はアルコキシル基、ＭはZn,Cu,Ni
又はCoを表わす。）次に、前記一般式［１］乃至［10］で示される化合物
の代表例を下記の表１に挙げるが、本発明はこれ等に限
定されるものではない。本発明に用いられる上記金属錯体類は、ハリー・ビー
・グレイ等がジャナル・オブ・ジ・アメリカン・ケミカ
ル・ソサイエティ 88巻 43〜50頁および4870〜4875
頁、もしくはシュランツアおよびマイベーク等によるジ
ャナル・オブ・ジ・アメリカン・ケミカル・ソサイエテ
ィ 87巻 1483〜1489頁により記載されている方法に準
じて合成される。上記化合物は近赤外域に吸収をもち、安定な光吸収色
素として有用でありかつ、高分子液晶に対して相溶性も
しくは分散性がよい。又中には二色性を有するものもあ
り、これら二色性を有する化合物を高分子液晶中に混合
すれば、熱的に安定なホスト−ゲスト型のメモリー及び
表示媒体を得ることもできる。また高分子液晶中には上記の化合物が二種類以上含有
されていてもよい。また、上記化合物と他の近赤外吸収色素や２色性色素
を組み合せてもよい。好適に組み合せられる近赤外吸収
色素の代表的な例としては、シアニン、メロシアニン、
フタロシアニン、テトラヒドロコリン、ジオキサジン、
アントラキノン、トリフェノジチアジン、キサンテン、
トリフェニルメタン、ピリリウム、クロコニウム、アズ
レンおよびトリフェニルアミン等の色素が挙げられる。なお、液晶に対する上記化合物の添加量は重量％で、
0.01％〜５％程度、好ましくは、0.05〜１％がよい。本
発明で用いる液晶は高分子サーモトロピック液晶であ
り、中間相であるネマチックやスメクチックやカイラル
スメクチックやコレステリックの相を利用する。本発明において利用できる高分子サーモトロピック液
晶の一次的基本構造としては、次の２つに分類される。メソーゲン基あるいは、比較的剛直で長い原子団が
屈曲性鎖で結ばれたもの。側鎖にメソーゲン基あるいは、比較的剛直で長い原
子団を有するもの。またカイラル不斉炭素をもつ強誘電性高分子液晶も利
用することができ、本発明に示すものと、該化合物との
相溶性および分散性はよいことが確かめられた。これら高分子サーモトロピック液晶の具体例を表２に
示す。本発明において、高分子液晶は異なる数種の高分子液
晶と混合して用いることも可能である。また高分子液晶
と低分子液晶との混合物として用いることも可能で、そ
の場合の重量比は高分子液晶１に対して低分子液晶は、
好ましくは10以下である。低分子液晶は特に限定するこ
とはなく、通常の低分子量の液晶を用いることができ
る。高分子液晶中には必要により通常のポリマー（例えば
オレフィン系樹脂、アクリル系樹脂、ポリスチレン系樹
脂、ポリエステル系樹脂、ポリウレタン系樹脂、ポリカ
ーボネート樹脂等）や、オリゴマー、各種酸化防止剤、
各種可塑剤、各種紫外線吸収剤、クエンチャー等が含有
されていてもよい。高分子液晶の薄膜化は高分子液晶を溶媒中に溶解し基
板上でスピンコートやディッピング等のコーティングを
したのち、乾燥させたり、基板間に高分子液晶を挟さみ
加熱加圧成形したり、あらかじめフィルム化しておきそ
れを用いてもよい。なお液晶層の厚さは0.01〜100μ程
度が好ましい。また、前記高分子液晶を一定方向に均一配向させるに
は、一般に知られているような配向方法を用いることが
できる。例えば、その配向方法として、ラビング法や斜方蒸着
法や２枚の基板に挟んでずり応力をかける方法や磁界を
印加しながらゆっくり相転移させる方法、スペーサーエ
ッヂで配向させる方法などが利用できる。又、第１図及び第２図は本発明の情報記録媒体の一実
施例を示す断面図である。第１図において、符号１は基
板を、２は配向膜を、３は本発明の記録層を、４は反射
層を表わす。又、第２図では符号1,2及び３は第１図の符号と同様
である。符号５は透明電極を又、６は電極兼反射層を示
す。第３図は記録媒体にレーザを照射して、書き込み及び
読み取りを行なう装置の概略図を示す。第３図におい
て、書き込みはレーザ発振器である半導体レーザ８より
出たレーザ光を光学系11により焦点をあわせて記録媒体
10へ入射する。読み取りはレーザ発振器である半導体レーザ８より出
たレーザ光を光学系11及びビームスプリッター７を通し
て記録媒体10へ照射し、その反射光を利用して再びビー
ムスプリッター７を通して光検出装置９にて読み取りを
行う。［作用］本発明の情報記録媒体は高分子液晶を含有する記録層
中に上記の近赤外吸収化合物のうち少なくとも一種を含
有するが、該近赤外吸収化合物が高分子液晶中で安定な
理由は明らかではないが、分解温度が高く熱的に安定な
ことや、フォトンモードの劣化に際し安定化剤としての
作用もあることが、高分子液晶中で安定し、光吸収能を
発揮するものと推定される。［実施例］以下、実施例に基づき本発明をより詳細に説明する。実施例１直径130mm、厚さ1.2mmのディスク状ガラス基板にポリ
アミック酸溶液（日立化成工業製、PIQ）を塗布し、加
熱後、ラビング処理をして、ポリイミドの配向膜を付与
した。この上に下記の側鎖型高分子液晶と近赤外吸収化合物
（表１の化合物No.7）を1,1,2−トリクロロエタンに混
合し、スピンナー法により塗布し、乾燥後厚み３μｍの
高分子液晶層を形成した。該化合物の添加量は、液晶に
対し、0.15wt％である。さらにこの高分子液晶層の上に外周部にスペーサー
（厚み３μｍ）を介して、反射膜（アルミ蒸着膜）を形
成したガラス基板上に前述と同様の方法でポリイミド配
向膜を設けた基板を重ね合せた。その断面構成の１部を
第１図に示す。上述の積層体を90℃に加熱して、徐冷す
ることにより、液晶層をネマチック層状態にし、情報記
録媒体を作製した。この記録媒体を第３図に示すように830nmの半導体レ
ーザ８により、記録パワー3.0mWで、記録部を透明基板
側から照射したところ、照射部の配向が乱れ、散乱状態
になった。次に読み出しパワー0.3mWで再生し、再生光
を光検出装置９で測定し、そのコントラスト比Ａ→未記録部分の信号強度、Ｂ→記録部の信号強度）を
算出した。また、記録を行った基板を90℃に加熱し徐冷して、記
録部の配向により、消去を行った。さらに記録・消去を繰返し、300回繰返した時点で再
生しコントラスト比を測定した。実施例２〜10 高分子液晶中に混合する近赤外吸収化合物を下記の表
３に示すものを用いた以外は全て実施例１と同様にし
て、情報記録媒体を作製した。また同様にしてコントラスト比を測定した。比較例１高分子液晶中に混合した近赤外吸収色素を下記に示す
ものを用いた以外は、全て実施例１と同様にして情報記
録媒体を作製した。ただし色素含有量は高分子液晶に対
し0.1wt％である。実施例11 透明電極層としてITOを蒸着した直径130mm、厚さ1.2m
mのガラス基板上にポリアミック酸溶液（日立化成工業
製PIQ）を塗布し、加熱後、ラビング処理をして、ポリ
イミド配向膜を形成した。この上に下記に示す強誘電高分子液晶と近赤外吸収化
合物（表１の化合物No.7）を1,1,2−トリクロロエタン
に溶解し、スピンナー法により塗布し、乾燥して厚み３
μｍの液晶層を形成した。実施例１と同様にスペーサーを介して、電極層兼反射
層（アルミ蒸着膜）を形成したガラス基板上に前述と同
様の方法でポリイミド配向膜を設けた基板を重ね合せ
た。その断面構成の１部を第２図に示す。上述の積層体を90℃まで加熱して、その後徐冷するこ
とにより、液晶層を一軸配向したスメクテックティック
相状態にして、電極間に電圧を印加し分極方向を一定方
向にそろえ情報記録媒体を作製した。この記録媒体にお
いて透明電極（ITO）とAI電極との間に逆電界を印加し
つつ、830nmの半導体レーザで記録パワー3.0mWで透明電
極側から記録部を照射することにより加熱し、自発分極
の向きを反転することにより、記録の書き込みを行っ
た。次に電界を印加しないで、再生出力0.3mWで偏光子を
通してレーザ光を照射し、反射光には分極の方向の違い
による複屈折の差が含まれるので、光検出装置に入射す
る、光強度を測定しコントラスト比を算出した。また再度ITO−Al電極間に順方向電界を印加しなが
ら、3.5mWのレーザパワーで照射し記録された部分又は
全面を消去した。再び記録、消去を繰返し300回繰返した時点で再生
し、コントラスト比を測定した。実施例12〜18 強誘電性高分子液晶中に混合する近赤外吸収化合物を
下記の表４に示すものを用いた以外は全て実施例11と同
様にして情報記録媒体を作製した。比較例２近赤外吸収化合物として比較例１で用いた化合物を使
用する以外は、実施例11と全く同様にして情報記録媒体
を作製した。以上の実施例および比較例のコントラスト比を測定し
た結果を表５にまとめて示す。［発明の効果］上述のように構成された本発明の情報記録媒体によれ
ば、熱的に安定で、記録・消去を繰返しても、記録のコ
ントラスト比が低下することがない優れた効果が得られ
る。DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]   The present invention relates to an information storage device having a recording layer containing a polymer liquid crystal.
Regarding recording media. [Conventional technology]   In recent years, as applications such as large capacity memory and display
Rewritable recording media is being actively developed.
You. One of them is known to use phase transition of liquid crystal.
I have.   For example, a pair of transparent electrodes or a suitable substrate
The liquid crystal layer that maintains the sandwiched alignment state
Is chemically transparent. Therefore, raise the temperature of this liquid crystal layer,
Phase transition temperature (nematic phase → liquid phase, or smecty
Liquid crystal layer after rapid cooling
Indicates a light scattering state without returning to the original transparent state. That is,
Recording and reading by this contrast difference
It is.   After writing, an electric field is applied between the electrodes of the recording medium.
Or by heating and slow cooling
The transition to a tick phase or the like is performed and can be eliminated.   In addition, while applying voltage, heating or
Erasing can also be performed by heating without applying pressure. Ma
Recently, it has a glass transition point,
Child liquid crystals have attracted attention.   Usually, a small and low-cost heating of the polymer liquid crystal layer is required.
In many cases, a simple semiconductor laser is used.
Oscillation wavelength is usually 650nm or more, and
Compared to gas lasers such as lasers and helium / neon lasers
Low laser beam power. Normal liquid crystal is such
Since there is no absorption in the near infrared region, the liquid crystal contains a light-absorbing dye.
It is known to have.   However, in general, dyes that absorb in the near infrared region
It is not thermally stable enough and may be partially written and erased repeatedly.
Decomposes, and it becomes impossible to obtain sufficient contrast.
There was a title. [Problems to be solved by the invention]   The present invention has been made to solve the problems of the prior art as described above.
It has absorption characteristics at near-infrared wavelengths.
And stable in a state dissolved or dispersed in the liquid crystal,
Information that does not degrade recording characteristics even after repeated writing and erasing
It is intended to provide a recording medium. [Means to solve the problem] and [Action]   The purpose of the present invention is to
At least one kind of near-infrared absorption shown below in molecular liquid crystal
It has been found that this can be achieved by incorporating a compound.   That is, the present invention has a recording layer containing a polymer liquid crystal.
An information recording medium, wherein the recording layer has the following general formula:
A small number selected from the compounds represented by [1] to [10]
Characterized in that at least one species is dissolved or dispersed
This is an information recording medium. General formula [1] (Where R₂₇Is a sulfur atom, substituted or unsubstituted amino
Group, oxygen atom or thioketone group, R₂₈Is a hydrogen atom, al
Represents a kill group, a halogen atom or an amino group, and M represents Zn, C
represents u or Ni. ) General formula [2] (Where R₂₉Is an alkyl group, aryl group or styryl group
And M represents Cu, Ni, or Co. ) General formula [3] (Where R₃₀Represents a hydrogen atom, a halogen atom, an alkyl group,
Represents an acyl group or an aryl group, and M represents Ni or Zr.
You. ) General formula [4] (Where R₃₁Is an alkyl or aryl group, M is Cu, Ni or
Represents Co. ) General formula [5] (Where R₃₂, R₃₃Is an alkyl or aryl group, M is Ni
Represents ) General formula [6] (Where R₃₄, R₃₅Is an alkyl group, amino group, aryl group
Or a furan group, or R₃₄And R₃₅Form an alicyclic compound with
Is also good. M represents Ni. ) General formula [7](Where R₃₆, R₃₇Represents a hydrogen atom, a halogen atom or
X represents an oxygen atom or a sulfur atom, and M represents Ni. ) General formula [8] (Where R₃₈, R₃₉Is hydrogen atom, alkyl group, halogen atom
X is an oxygen atom or a sulfur atom, M is Ni,
YRepresents a quaternary ammonium cation. ) General formula [9] (Where R₄₀Represents an amino group and M represents Cu, Ni, Co or Pd.
You. ) General formula [10] (Where R₄₁Represents a hydrogen atom, a halogen atom, an alkyl group,
Acyl group, nitro group or alkoxyl group, M is Zn, Cu, Ni
Or represents Co. )   Next, the compounds represented by the general formulas [1] to [10]
Table 1 below shows typical examples, but the present invention is not limited to these.
It is not specified.   The metal complexes used in the present invention are Harry B.
・ Gray etc. is Janal of the American Chemica
Le Society 88: 43-50 and 4870-4875
Page or Schranzur and My Bake etc.
Canal of the American Chemical Society
The method described in Vol. 87, pp. 1483-1489
Are synthesized together.   The above compound has absorption in the near-infrared region and stable light absorption color
Useful as a liquid crystal and compatible with polymer liquid crystals
Or good dispersibility. Some have dichroism
These dichroic compounds are mixed in a polymer liquid crystal.
Then, a thermally stable host-guest type memory and
A display medium can also be obtained.   The polymer liquid crystal contains two or more of the above compounds
It may be.   In addition, the above compound and another near-infrared absorbing dye or dichroic dye
May be combined. Near infrared absorption suitably combined
Representative examples of dyes include cyanine, merocyanine,
Phthalocyanine, tetrahydrocholine, dioxazine,
Anthraquinone, triphenodithiazine, xanthene,
Triphenylmethane, pyrylium, croconium, as
Dyes such as len and triphenylamine.   The amount of the compound added to the liquid crystal is% by weight.
About 0.01% to 5%, preferably 0.05 to 1%. Book
The liquid crystal used in the present invention is a polymer thermotropic liquid crystal.
Nematic, smectic and chiral intermediates
Use smectic and cholesteric phases.   Polymer thermotropic liquid usable in the present invention
The primary basic structure of a crystal is classified into the following two.   Mesogen groups or relatively rigid and long atomic groups
Those connected by flexible chains.   A mesogen group in the side chain or a relatively rigid and long base
Those with gangs.   Also useful are ferroelectric polymer liquid crystals with chiral asymmetric carbon.
Can be used.
It was confirmed that compatibility and dispersibility were good.   Table 2 shows specific examples of these polymer thermotropic liquid crystals.
Show.   In the present invention, the polymer liquid crystal is composed of several different polymer liquids.
It is also possible to use a mixture with a crystal. Also polymer liquid crystal
Can be used as a mixture of
In the case of the above, the weight ratio of the low-molecular liquid crystal to the high-molecular liquid crystal 1 is as follows.
Preferably it is 10 or less. Low-molecular liquid crystals are particularly limited
Instead, ordinary low molecular weight liquid crystals can be used.
You.   If necessary, a normal polymer (eg,
Olefin resin, acrylic resin, polystyrene resin
Fat, polyester resin, polyurethane resin, polycarbonate
-Carbonate resin), oligomers, various antioxidants,
Contains various plasticizers, various UV absorbers, quenchers, etc.
It may be.   Polymer thin film is formed by dissolving polymer liquid crystal in solvent
Coating such as spin coating and dipping on the board
After drying, sandwich the polymer liquid crystal between the substrates.
Heat and pressure molding, or filming in advance
These may be used. The thickness of the liquid crystal layer is about 0.01-100μ
Degree is preferred.   Also, it is necessary to uniformly align the polymer liquid crystal in a certain direction.
Uses an orientation method that is generally known
it can.   For example, rubbing or oblique deposition
Method, a method of applying shear stress between two substrates, and a magnetic field
A method of causing a phase transition slowly while applying a voltage
For example, a method of aligning with the edge can be used.   FIGS. 1 and 2 show one embodiment of the information recording medium of the present invention.
It is sectional drawing which shows an Example. In FIG. 1, reference numeral 1 denotes a base.
Plate, 2 for alignment film, 3 for recording layer of the present invention, 4 for reflection
Represents a layer.   In FIG. 2, reference numerals 1, 2 and 3 are the same as those in FIG.
It is. Reference numeral 5 denotes a transparent electrode, and 6 denotes an electrode / reflection layer.
You.   FIG. 3 shows that the recording medium is irradiated with a laser,
1 shows a schematic view of an apparatus for reading. Fig. 3
Writing is performed by a semiconductor laser 8 which is a laser oscillator.
The emitted laser light is focused by the optical system 11 and the recording medium
It is incident on 10.   Reading is performed by the semiconductor laser 8 which is a laser oscillator.
Laser beam passed through the optical system 11 and the beam splitter 7
And irradiates the recording medium 10 with the reflected light.
Read by the photodetector 9 through the musplitter 7
Do. [Action]   The information recording medium of the present invention is a recording layer containing a polymer liquid crystal.
Contains at least one of the above near infrared absorbing compounds.
Has, but the near-infrared absorbing compound is stable in the polymer liquid crystal
The reason is not clear, but the decomposition temperature is high and thermally stable
And as a stabilizer in the degradation of photon mode
It is stable in the polymer liquid crystal and has a light absorption ability.
It is presumed to exert. [Example]   Hereinafter, the present invention will be described in more detail based on examples. Example 1   Polypropylene on a disc-shaped glass substrate with a diameter of 130 mm and a thickness of 1.2 mm
Apply an amic acid solution (PIQ, manufactured by Hitachi Chemical Co., Ltd.)
After heating, rubbing treatment gives polyimide alignment film
did.   On this, the following side chain type polymer liquid crystal and near infrared absorbing compound
(Compound No. 7 in Table 1) mixed with 1,1,2-trichloroethane
And applied by a spinner method, and dried to a thickness of 3 μm.
A polymer liquid crystal layer was formed. The amount of the compound added depends on the liquid crystal.
On the other hand, it is 0.15 wt%.   Furthermore, a spacer is provided on the outer periphery of the polymer liquid crystal layer.
(Thickness: 3μm), forming a reflective film (aluminum deposited film)
Polyimide is placed on the glass substrate by the same method as described above.
The substrates provided with the facing films were overlaid. Part of the cross-sectional configuration
As shown in FIG. Heat the above laminate to 90 ° C and slowly cool
In this way, the liquid crystal layer is turned into a nematic layer
A recording medium was prepared.   As shown in FIG. 3, this recording medium is a 830 nm semiconductor laser.
With a recording power of 3.0 mW, the recording part is transparent substrate
When irradiated from the side, the orientation of the irradiated part is disturbed, scattering state
Became. Next, reproduction is performed with a read power of 0.3 mW, and the reproduction light
Is measured by the photodetector 9 and its contrast ratio is measured. A → Signal strength of unrecorded part, B → Signal strength of recorded part)
Calculated.   In addition, the substrate on which recording was performed was heated to 90 ° C. and gradually cooled,
Erasing was performed according to the orientation of the recording portion.   Recording and erasing are repeated, and after 300 repetitions,
Then, the contrast ratio was measured. Examples 2 to 10   The near-infrared absorbing compounds mixed in the polymer liquid crystal are listed in the table below.
Except that the one shown in No. 3 was used,
Thus, an information recording medium was manufactured.   The contrast ratio was measured in the same manner. Comparative Example 1   The near infrared absorbing dye mixed in the polymer liquid crystal is shown below
Information recording was performed in the same manner as in Example 1 except that
A recording medium was prepared. However, the pigment content is higher than that of polymer liquid crystal.
And 0.1 wt%. Example 11   130mm in diameter and 1.2m in thickness with ITO deposited as a transparent electrode layer
Polyamic acid solution (Hitachi Chemical Industry Co., Ltd.)
PIQ), rubbing after heating,
An imide alignment film was formed.   On this, ferroelectric polymer liquid crystal shown below and near infrared absorption
Compound (Compound No. 7 in Table 1) was converted to 1,1,2-trichloroethane
, Coated by spinner method and dried to a thickness of 3
A μm liquid crystal layer was formed.   Electrode layer and reflection via a spacer as in Example 1.
Same as above on a glass substrate on which a layer (aluminum-deposited film) is formed
Laminate substrates with polyimide alignment film by the same method
Was. FIG. 2 shows a part of the sectional configuration.   The above-mentioned laminate is heated to 90 ° C and then slowly cooled.
With this, smectic tics with a uniaxially oriented liquid crystal layer
In the phase state, apply a voltage between the electrodes to keep the polarization direction constant.
The information recording medium was manufactured in the same direction. This recording medium
And apply a reverse electric field between the transparent electrode (ITO) and the AI electrode.
While using a 830nm semiconductor laser with a recording power of 3.0mW
Heating by irradiating the recording part from the pole side, spontaneous polarization
Record writing by reversing the orientation of
Was.   Next, without applying an electric field, the polarizer was turned on at a reproduction output of 0.3 mW.
The laser beam is radiated and the reflected light has a different polarization direction.
Is included in the photodetector because
The light intensity was measured and the contrast ratio was calculated.   While applying a forward electric field between the ITO and Al electrodes again,
The part recorded by irradiating with 3.5mW laser power or
The entire surface was erased.   Playback when recording and erasing are repeated 300 times
Then, the contrast ratio was measured. Examples 12 to 18   Near infrared absorbing compound mixed with ferroelectric polymer liquid crystal
All the same as in Example 11 except that the ones shown in Table 4 below were used.
Thus, an information recording medium was produced. Comparative Example 2   The compound used in Comparative Example 1 was used as the near-infrared absorbing compound.
Information recording medium in exactly the same manner as in Example 11 except for using
Was prepared.   The contrast ratios of the above Examples and Comparative Examples were measured.
The results are summarized in Table 5. [The invention's effect]   According to the information recording medium of the present invention configured as described above,
For example, it is thermally stable.
Excellent effect without lowering the contrast ratio
You.

【図面の簡単な説明】第１図、第２図は本発明の情報記録媒体の断面図、第３
図は記録、再生、消去の光学系の模式図を示す。１……基板、２……配向膜３……記録層、４……反射層５……透明電極、６……電極兼反射層７……ビームスプリッター８……半導体レーザ、９……光検出装置 10……記録媒体、11……光学系 12……反射鏡、13……偏光子BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an information recording medium according to the present invention, and FIG.
The figure shows a schematic diagram of an optical system for recording, reproducing, and erasing. DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Alignment film 3 ... Recording layer 4 ... Reflection layer 5 ... Transparent electrode 6 ... Electrode / reflection layer 7 ... Beam splitter 8 ... Semiconductor laser 9 ... Light detection Device 10: Recording medium, 11: Optical system 12, Reflecting mirror, 13: Polarizer

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.⁶ 識別記号庁内整理番号ＦＩ技術表示箇所Ｇ１１Ｂ 7/24 ５１６Ｂ４１Ｍ 5/26 １０２ (72)発明者大西敏一東京都大田区下丸子３丁目30番２号キヤノン株式会社内 (56)参考文献特開昭60−165293（ＪＰ，Ａ) 特開昭60−165294（ＪＰ，Ａ) 特開昭60−166487（ＪＰ，Ａ) 特開昭60−168691（ＪＰ，Ａ) 特開昭62−157341（ＪＰ，Ａ)──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G11B 7/24 516 B41M 5/26 102 (72) Inventor Shunichi Onishi 3-chome Shimomaruko, Ota-ku, Tokyo 30-2 Canon Inc. (56) References JP-A-60-165293 (JP, A) JP-A-60-165294 (JP, A) JP-A-60-166487 (JP, A) JP 60-166861 (JP, A) JP-A-62-157341 (JP, A)

Claims

(57) [Claims] 1. Information recording medium having recording layer containing polymer liquid crystal
Wherein the recording layer has the following general formulas [1] to [10]
Dissolves at least one selected from the compounds represented by
Or an information recording medium characterized by being dispersed
body. General formula [1] (Where R₂₇Is a sulfur atom, substituted or unsubstituted amino
Group, oxygen atom or thioketone group, R₂₈Is a hydrogen atom, al
Represents a kill group, a halogen atom or an amino group, and M represents Zn, C
represents u or Ni. ) General formula [2] (Where R₂₉Is an alkyl group, aryl group or styryl group
And M represents Cu, Ni, or Co. ) General formula [3] (Where R₃₀Represents a hydrogen atom, a halogen atom, an alkyl group,
Represents an acyl group or an aryl group, and M represents Ni or Zr.
You. ) General formula [4] (Where R₃₁Is an alkyl or aryl group, M is Cu, Ni or
Represents Co. ) General formula [5] (Where R₃₂, R₃₃Is an alkyl or aryl group, M is Ni
Represents ) General formula [6] (Where R₃₄, R₃₅Is an alkyl group, amino group, aryl group
Or a furan group, or R₃₄And R₃₅Form an alicyclic compound with
Is also good. M represents Ni. ) General formula [7] (Where R₃₆, R₃₇Represents a hydrogen atom, a halogen atom or
X represents an oxygen atom or a sulfur atom, and M represents Ni. ) General formula [8](Where R₃₈, R₃₉Is hydrogen atom, alkyl group, halogen atom
X is an oxygen atom or a sulfur atom, M is Ni,
YRepresents a quaternary ammonium cation. ) General formula [9] (Where R₄₀Represents an amino group and M represents Cu, Ni, Co or Pd.
You. ) General formula [10] (Where R₄₁Represents a hydrogen atom, a halogen atom, an alkyl group,
Acyl group, nitro group or alkoxyl group, M is Zn, Cu, Ni
Or represents Co. ) 2. A polymer liquid in which the polymer liquid crystal has a chiral asymmetric carbon
Crystal, and the above-mentioned general
Selected from the compounds represented by the formulas [1] to [10].
Claims in which at least one is dissolved or dispersed
2. The information recording medium according to claim 1, wherein: 3. Patent application where the polymer liquid crystal is a ferroelectric polymer liquid crystal
3. The information recording medium according to claim 1 or claim 2.