JP4274345B2 - Thermoreversible recording medium, thermoreversible recording label, member having information storage unit, and image processing method - Google Patents

Description

【化２】

Ｒ₁−Ｘ−Ｒ₃ （２）
〔式（２）中、Ｘはシュウ酸ジアミド結合またはジアシルヒドラジド結合を示し、Ｒ₁、Ｒ₃はＣＨ₃（ＣＨ₂)_m−またはＣＨ₃（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、ｍ、ｎは０〜３０が好ましい。〕
【００２７】
【化３】

【化４】

〔一般式（３）、（４）中、Ｘ、Ｙの少なくとも１つはウレタン結合、スルホニル結合、尿素結合、アミド結合、シュウ酸ジアミド結合、ジアシルヒドラジド結合示す。Ｒ₁、Ｒ₂は−（ＣＨ₂)_m−又は−（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、Ｒ₃はＣＨ₃（ＣＨ₂)_m−又はＣＨ₃（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、［Ａ］はフェニル基、シクロヘキシル基下記一般式（iii）〜（ｖ）で示される基を示し、ｍ、ｎは０〜３０が好ましい。〕
【００２８】
【化５】

【化６】

【化７】

〔式（Ｖ）中、ｌは１〜３であり、ＺはＲ₁ＯＣＯ−、Ｒ₁Ｏ−、Ｒ₁−を示し、Ｒ₁はＣＨ₃（ＣＨ₂)_m−またはＣＨ₃（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、ｍ、ｎは０〜３０が好ましい。〕
【００２９】
【化８】

【化９】

〔式（５）、（６）中、Ｘはウレタン結合、スルホニル結合、尿素結合、アミド結合、シュウ酸ジアミド結合、ジアシルヒドラジド結合のいずれかを示す。Ｒ₁は−（ＣＨ₂)_m−又は−（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、Ｒ₂はＣＨ₃（ＣＨ₂)_m−又はＣＨ₃（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を示し、ｍ、ｎは０〜３０が好ましい。〕
【００３０】
直鎖炭化水素含有化合物（Ａ）のより具体的な例としては、例えば、下記一般式（７）〜（２２）で表されるものを挙げることができるが、これらに限定されるものではない。
Ｒ₁−ＯＯＣＮＨ−Ｒ₂−ＮＨＣＯＯ−Ｒ₃ （７）
Ｒ₁−ＮＨＣＯＯ−Ｒ₂−ＯＯＣＮＨ−Ｒ₃ （８）
Ｒ₁−ＳＯ₂−Ｒ₂−ＳＯ₂−Ｒ₃ （９）
Ｒ₁−ＮＨＣＯＣＯＮＨ−Ｒ₃ （１０）
Ｒ₁−ＣＯＮＨＮＨＣＯ−Ｒ₃ （１１）
Ｒ₁−ＮＨＣＯ−Ｒ₂−ＮＨＣＯＮＨ−Ｒ₃ （１２）
Ｒ₁−ＣＯＮＨ−Ｒ₂−ＮＨＣＯＮＨ−Ｒ₃ （１３）
Ｒ₁−ＮＨＣＯＯ−Ｒ₂−ＮＨＣＯＮＨ−Ｒ₃ （１４）
Ｒ₁−ＮＨＣＯＮＨ−Ｒ₂−ＮＨＣＯＮＨ−Ｒ₃ （１５）
【００３１】
【化１０】

【化１１】

【化１２】

【化１３】

【化１４】

【化１５】

【化１６】

〔式（７）〜（２２）中、Ｒ₁、Ｒ₃はＣＨ₃（ＣＨ₂)_m−又はＣＨ₃（ＣＨ₂)_m−Ｏ−（ＣＨ₂)_n−を、Ｒ₂は−（ＣＨ₂)_m−又は上記一般式（ｉ）又は（ii）で表される基を示し、ｍ、ｎは０〜３０が好ましい。）
【００３２】
ここに、ｍ、ｎは１〜３０が好ましく、３〜２６がより好ましく、５〜２２がさらに好ましい。
分子中の直鎖炭化水素の合計の炭素数は８以上が好ましく、１０以上がより好ましく、１４以上がさらに好ましい。
また、分子中の直鎖炭化水素の合計の炭素数は６０以下が好ましく、５０以下がより好ましく、４０以下がさらに好ましい。
この炭素数が少なすぎると、樹脂との相溶性が向上し、低分子物質粒子が形成できにくくなって、コントラストが低下するという問題が生じ、炭素数が多すぎると、低融点低分子物質との相溶性が低下し、透明化温度範囲を拡大できなくなるという問題を生じるので望ましくない。
【００３３】
上記一般式（７）の化合物としては、例えば、以下のものが挙げられる。

【００３４】
上記一般式（８）の化合物としては、例えば、以下のものが挙げられる。

【化１７】

【００３５】
上記一般式（９）の化合物としては、例えば、以下のものが挙げられる。

【００３６】
上記一般式（１０）の化合物としては、例えば、以下のものが挙げられる。

【００３７】
上記一般式（１１）の化合物としては、例えば、以下のものが挙げられる。

【００３８】
上記一般式（１２）の化合物としては、例えば、以下のものが挙げられる。

【００３９】
上記一般式（１３）の化合物としては、例えば、以下のものが挙げられる。
ＣＨ₃（ＣＨ₂)₁₆ＣＯＮＨ（ＣＨ₂)₆ＮＨＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃ １４９℃
【００４０】
上記一般式（１４）の化合物としては、例えば、以下のものが挙げられる。
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＯ（ＣＨ₂)₂ＮＨＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃ １２７℃
【００４１】
上記一般式（１５）の化合物としては、例えば、以下のものが挙げられる。

【００４２】
上記一般式（１６）の化合物としては、例えば、以下のものが挙げられる。
【化１８】

【化１９】

【化２０】

【００４３】
上記一般式（１７）の化合物としては、例えば、以下のものが挙げられる
【化２１】

【００４４】
上記一般式（１８）の化合物としては、例えば、以下のものが挙げられる
【化２２】

上記一般式（１９）の化合物としては、例えば、以下のものが挙げられる。
【化２３】

【００４５】
上記一般式（２０）の化合物としては、例えば、以下のものが挙げられる。
【化２４】

【００４６】
上記一般式（２１）の化合物としては、例えば、以下のものが挙げられる。
【化２５】

【００４７】
上記一般式（２２）の化合物としては、例えば、以下のものが挙げられる。
【化２６】

【００４８】
以下に、上記直鎖炭化水素含有化合物（Ａ）の合成方法の例を示すが、こ
れらに限定されるものではない。
〔上記一般式（７）で表される化合物〕
オクタデシルオキシーＮ−［６−（オクタデシルオキシカルボニルアミノ）ヘキシル］カルボキサミド〔ＣＨ₃（ＣＨ₂)₁₇ＯＯＣＮＨ（ＣＨ₂)₆ＮＨＣＯＯ（ＣＨ₂)₁₇ＣＨ₃〕の合成例。
ステアリルアルコール２０．１ｇ及びヘキサメチレンジイソシアネート５．１ｇのテトラヒドロフラン溶液１２５．５ｇを還流下で３時間攪拌した。
析出した結晶を濾別、トルエンによる再結晶を行い、目的の化合物１７．７ｇを得た。
【００４９】
〔上記一般式（８）で表される化合物〕
１−オクタデシル［４−（Ｎ−オクタデシルカルボニルオキシ）ブトキシ］カルボキサミド〔ＣＨ₃(ＣＨ₂)₁₇ＮＨＣＯＯ（ＣＨ₂)₄ＯＯＣＮＨ（ＣＨ₂)₁₇ＣＨ₃〕の合成例。
１，４−ブタンジオール２．６ｇ及びステアリルイソシアネート１８．０ｇのテトラヒドロフラン溶液１０３．０ｇを還流下で５時間攪拌した。
析出した結晶を濾別、トルエンによる再結晶を行い、目的の化合物１７．５ｇを得た。
【００５０】
〔上記一般式（９）で表される化合物〕
１，２−ビス（オクタデシルスルホニル）エタン〔ＣＨ₃（ＣＨ₂)₁₇ＳＯ₂（ＣＨ₂)₂ＳＯ₂（ＣＨ₂)₁₇ＣＨ₃〕の合成例。
ステアリルメルカプタン３５．５ｇ及び水酸化カリウム８．５ｇのエタノール溶液１７７．５ｇに、１，２−ジブロモエタン１１．１ｇを、室温下で滴下し、還流下で５時間攪拌した。攪拌終了後、０．８％塩酸水溶液２７５ｇを室温下で加えた。
析出した結晶を濾別、水洗、乾燥させることにより、１，２−ジオクタデシルチオエタンが１８．４ｇ得られた。
次に、１，２−ジオクタデシルチオエタン１８．４ｇ、酢酸１８４ｇ及び過酸化水素水（３５％）１８４ｇ混合物を８０〜９０℃下で、５時間攪拌した。
反応溶液を室温下で、イオン交換水に加え、析出した結晶を濾別、トルエンによる再結晶を行い、目的の化合物を１０．６ｇ得た。
【００５１】
〔上記一般式（１０）で表される化合物〕
Ｎ−オクタデシル−Ｎ−オクタデシルエタンー１，２ジアミド
〔ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃〕の合成例。
ステアリルアミン５３．５ｇ及びピリジン１５．７ｇのテトラヒドロフラン溶液５９９．２ｇに、室温下で、オキサリルクロリド１２．０ｇのテトラヒドロフラン溶液１２０．０ｇを滴下した。滴下後、室温下で５時間攪拌した。
析出した結晶を濾別、水洗、トルエンによる再結晶を行い、目的の化合物１９．６ｇを得た。
【００５２】
〔上記一般式（１１）で表される化合物〕
Ｎ−（オクタデカノイルアミノ）オクタデカンアミド
〔ＣＨ₃（ＣＨ₂)₁₆ＣＯＮＨＮＨＣＯ（ＣＨ₂)₁₇ＣＨ₃〕の合成例。
ステアリン酸ヒドラジド２０．０ｇ、ステアリン酸２１．０ｇ及び１−ヒドロキシベンゾトリアゾール１０．３ｇのテトラヒドロフラン溶液２０５．０ｇにジイソプロピルカロボジイミド９．３ｇを室温下で滴下し、還流下で３時間攪拌した。析出した結晶を濾別、イソプロピルアルコールによる再結晶を行い、目的の化合物２３．９ｇを得た。
【００５３】
〔上記一般式（１２）で表される化合物〕
Ｎ−（３−エトキシプロピル）−１２−（Ｎ‘−オクタデシルウレイド）ドデカン酸アミド
〔ＣＨ₃ＣＨ₂Ｏ（ＣＨ₂)₃ＮＨＣＯ（ＣＨ₂)₁₁ＮＨＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃ 〕の合成例
オクタデシルイソシアネート３０．５ｇ及び１２−アミノドデカン酸２１．４ｇのジメチルホルムアミド溶液を６０〜７０℃で８時間攪拌した。析出した結晶を濾別、トルエンによる再結晶を行い、得られた化合物４５．２ｇとエトキシプロピルアミン１２．７ｇ、１−ヒドロキシベンゾトリアゾール１５．６ｇのメチルエチルケトン溶液にジイソプロピリカルボジイミド１７．８ｇを５０〜６０℃で滴下し、５時間攪拌した。
析出した結晶を濾別、イソプロピルアルコールによる再結晶を行い、目的の化合物４６．１ｇを得た。
【００５４】
〔上記一般式（１７）で表される化合物〕
Ｎ−ベンジル−Ｎ’−オクタデシル尿素
【化２７】

オクタデシルイソシアネート１４．８ｇ及びベンジルアミン６．１ｇのメチルエチルケトン溶液を還流下で６時間攪拌した。析出した結晶を濾別、イソプロピルアルコールによる再結晶を行い、目的の化合物１７．２ｇを得た。
【００５５】
〔上記一般式（１９）で表される化合物〕
６−〔（Ｎ−オクタデシルカルバモイル）アミノ〕−Ｎ−フェニルヘキサン酸アミド
【化２８】

オクタデシルイソシアネート１４．１ｇ及び６−アミノカプロン酸６．２ｇのジメチルホルムアミド溶液を５０〜６０℃で５時間攪拌した。析出した結晶を濾別、トルエンによる再結晶を行い、得られた化合物１８．７ｇとアニリン５．０ｇ、１−ヒドロキシベンゾトリアゾール６．５ｇのメチルエチルケトン溶液にジイソプロピリカルボジイミド５．５ｇを滴下し、還流下で５時間攪拌した。
析出した結晶を濾別、エチルアルコールによる再結晶を行い、目的の化合物１６．３ｇを得た。
【００５６】
〔上記一般式（２２）で表される化合物〕
〔３，５―ビス（Ｎ−オクタデシルカルバモイロキシ）フェノキシ〕−Ｎ−オクタデシルカルボキサミド
【化２９】

ベンゼン−１，３，５−トリオール４．３ｇ及びオクタデシルイソシアネート３３．４ｇのテトラヒドロフランを溶液を還流下で８時間攪拌した。析出した結晶を濾別、トルエンによる再結晶を行い、目的の化合物２５．６ｇを得た。
【００５７】
本発明の第二の課題は、有機低分子物質として直鎖状炭化水素含有化合物（Ａ）に加えて、さらに直鎖状炭化水素含有化合物（Ａ）の融点よりも２０℃以上低い融点を有するカルボキシル基を有さない直鎖炭化水素含有化合物（Ｂ）を用いることによって解決される。
この直鎖状炭化水素含有化合物（Ｂ）としては、一種または二種以上を用いることができる。
直鎖炭化水素含有化合物（Ｂ）は、融点が５０℃以上、１００℃未満であることが好ましい。この融点は６０℃以上がより好ましく、７０℃以上がさらに好ましく、また、９０℃以下がより好ましい。
この融点が低すぎると、画像耐熱性が低下し、高すぎると、透明化温度幅が拡大できず、消去性が低下するので望ましくない。
【００５８】
直鎖炭化水素含有化合物（Ａ）と直鎖炭化水素含有化合物（Ｂ）との混合比は、重量比で８０：２０〜１：９９が好ましい。
この混合比は、直鎖炭化水素含有化合物（Ｂ）の比率が９７以下がより好ましく、９５以下がさらに好ましく、９０以下がより特に好ましい。
また、３０以上が好ましく、４０以上がより好ましく、５０以上がさらに好ましい。
直鎖炭化水素含有化合物（Ａ）（Ｂ）は、それぞれ１種用いてもよく、２種以上を混合して用いてもよい。
直鎖炭化水素含有化合物（Ｂ）の比率が高すぎると、透明化温度の中でも低温側では透明度が高くなり、高温側では透明度が低くなるという透明度の差が生じ、均一に透明化できなくなるので望ましくない。
また、直鎖炭化水素含有化合物（Ｂ）の比率が低すぎると、充分な透明性が得られなくなるので望ましくない。
【００５９】
直鎖炭化水素含有化合物（Ｂ）としては、脂肪酸エステル、高級アルキル基を有するケトン、二塩基酸エステル、多価アルコールジ脂肪酸エステル、脂肪族モノアミド化合物、脂肪族モノウレア化合物等が挙げられるが、これらに限定されるものではない。
【００６０】
直鎖炭化水素含有化合物（Ｂ）の具体例を、以下に列挙する。
脂肪酸エステルとしては、例えば、ラウリン酸オクタデシル、ラウリン酸ドコシル、ミリスチン酸ドコシル、パルミチン酸ドデシル、パルミチン酸テトラデシル、パルミチン酸ペンタデシル、パルミチン酸ヘキサデシル、パルミチン酸オクタデシル、パルミチン酸トリアコンチル、パルミチン酸オクタデシル、パルミチン酸ドコシル、ステアリン酸ビニル、ステアリン酸プロピル、ステアリン酸イソプロピル、ステアリン酸ブチル、ステアリン酸アミル、ステアリン酸ヘプチル、ステアリン酸オクチル、ステアリン酸テトラデシル、ステアリン酸ヘキサデシル、ステアリン酸ヘプタデシル、ステアリン酸オクタデシル、ステアリン酸ドコシル、ステアリン酸ヘキサコシル、ステアリン酸トリアコンチル、ベヘン酸ドデシル、ベヘン酸オクタデシル、ベヘン酸ドコシル、リグノセリン酸トラコシル、メリシン酸ミリシル等が挙げられる。
【００６１】
高級アルキル基を有するケトンとしては、例えば、８−ペンタデカノン、９−ヘプタデカノン、１０−ノナデカノン、１１−ヘンエイコサノン、１２−トリコサノン、１４−ヘプタコサノン、１６−ヘントリアコンタノン、１８−ペンタトリアコンタノン、２２−トリテトラコンタノン、２−ペンタデカノン、２−ヘキサデカノン、２−ヘプタデカノン、２−オクタデカノン、２−ノナデカノン等が挙げられる。
【００６２】
二塩基酸エステルとしては、ジエステルが好ましく、下記一般式（２３）で表わされるものである。
ＲＯＯＣ−（ＣＨ₂)_n−ＣＯＯＲ’ （１１）
〔式（２３）中、Ｒ，Ｒ’はアルキル基を示し、このアルキル基の炭素数は１〜３０が好ましく、１〜２２がより好ましい。Ｒ，Ｒ’は同一であっても異なっていてもよい。ｎは、１〜３０が好ましく、２〜２０がより好ましい。〕
具体的には、コハク酸ジエステル、アジピン酸ジエステル、セバシン酸ジエステル、１，１８−オクタデカメチレンジカルボン酸エステル等が挙げられる。
【００６３】
多価アルコールジ脂肪酸エステルとしては、下記一般式（２４）で表わされるものが挙げられる。
ＣＨ₃（ＣＨ₂)_{m − 2}ＣＯＯ（ＣＨ₂)_nＯＯＣ（ＣＨ₂)_{m − 2}ＣＨ₃ （２４）
（式（２４）、ｎは２〜４０、好ましくは３〜３０、より好ましくは４〜２２である。ｍは２〜４０、好ましくは３〜３０、より好ましくは４〜２２である。〕
具体的には、１，３プロパンジオールジアルカン酸エステル、１，６ヘキサンジオールジアルカン酸エステル、１，１０デカンジオールジアルカン酸エステル、１，１８オクタデカンジオールジアルカン酸エステル等が挙げられる。
【００６４】
脂肪酸モノアミドとしては、下記一般式（２５）で表されるものが挙げられる。
Ｒ−ＣＯＮＨ−Ｒ （２５）
（式（２５）中、Ｒは炭素数１〜２５の直鎖炭化水素鎖、Ｒは炭素数１〜２６の直鎖状炭化水素鎖、メチロール基又は水素を示し、Ｒ、Ｒの少なくともいずれか一方が炭素数１０以上の直鎖炭化水素鎖である。）
具体的には、Ｎ−ラウリルラウリン酸アミド、Ｎ−パルミチルパルミチン酸アミド、Ｎ−ステアリルパルミチン酸アミド、Ｎ−ベヘニルパルミチン酸アミド、Ｎ−パルミチルステアリン酸アミド、Ｎ−ステアリルステアリン酸アミド、Ｎ−ベヘニルステアリン酸アミド、Ｎ−パルミチルベヘン酸アミド、Ｎ−ステアリルベヘン酸アミド、Ｎ−ベヘニルベヘン酸アミド等を挙げることができる。
【００６５】
脂肪族ウレア化合物としては、下記一般式（２６）で表されるものが挙げられる。
Ｒ−ＮＨＣＯＮＨ−Ｒ （２６）
〔式（２６）中、Ｒ、Ｒは、アルキル基、脂環族基、芳香族基を示し、少なくともいずれか一方は炭素数１〜２６の直鎖炭化水素鎖である。）
具体的には、Ｎ−ブチル−Ｎ−ステアリル尿素、Ｎ−フェニル−Ｎ−ステアリル尿素、Ｎ−ステアリル−Ｎ−ステアリル尿素、Ｎ−ベヘニル−Ｎ−ステアリル尿素、Ｎ−ステアリル−Ｎ−ベヘニル尿素、Ｎ−ベヘニル−Ｎ−ベヘニル尿素等が挙げられる。
【００６６】
本発明の熱可逆記録媒体は、温度に依存して透明状態と不透明状態とが可逆的に変化する条件として下記（ｉ）〜（iii）を合わせ持つものであることが好ましい。
（ｉ）透明化上限温度が１１５℃以上であること。
（ii）透明化上限温度と不透明化下限温度の温度差が２０℃以下であること。
（iii）透明化温度幅が３０℃以上であること。
【００６７】
透明化上限温度（ＴＷＸ）、不透明化（白濁化）下限温度（ＴＶＯ）、透明化上限温度と不透明化下限温度の温度差（ΔＴＷＶ）、透明化開始温度（ＴＷＤ）、透明化温度幅（ΔＴＺ）は、下記のとおり決定される。まず、白濁化された熱可逆記録媒体を用意する。
透明化された媒体や十分に白濁されていない媒体を用いるには、十分に加熱したホットプレートに媒体を押しあて加熱することによって、事前に媒体を白濁させる。加熱する時間は１０〜３０秒程度でよい。
加熱する温度が白濁化するために十分な温度であることを確認するのは、その温度よりやや高い温度（例えば、１０℃高い温度）で再度加熱してみればよい。
白濁度が両者で変わらなければ最初の加熱温度が白濁化するために十分に高い温度であったことになる。
やや高い温度で加熱した方が白濁度が高くなっていれば、最初の温度ではまだ温度が低かったことになり、加熱温度を上げて再度同じことを繰り返せばよい。
【００６８】
次に、この白濁化された記録媒体を温度を変えて加熱し、透明になる温度を調べる。記録媒体の加熱には熱傾斜試験機（東洋精機製ＨＧ−１００）を用いる。
この熱傾斜試験機は、５つの加熱ブロックを持ち、各ブロックは個別に温度を設定でき、加熱時間、圧力をコントロールすることも可能であり、設定された条件で、一度に５つの異なる温度で媒体を加熱することができる。
具体的には、加熱時間を１秒とし、加熱時の圧力は約２．５ｋｇ／ｃｍとし、加熱温度は、加熱しても白さが変化しない低温度から１〜５℃の等温度間隔で十分に白濁する温度まで加熱する。
熱ブロックへの媒体の粘着を防ぐため、ポリイミドやポリアミドの薄い（１０μｍ以下）フィルムを上にのせてもよい。
このように加熱した後、常温に冷却し、マクベスＲＤ−９１４反射濃度計を用い、各温度で加熱した部分の濃度を測定し、図２のように横軸を熱傾斜試験機の設定温度、縦軸を反射濃度としたグラフを作成する。
【００６９】
図２は、この熱傾斜試験機の設定温度と反射濃度との関係を示すグラフである。
熱可逆記録媒体が透明な支持体を用いている場合には、光を吸収するシートか、Ａｌ等の金属を蒸着した光を正反射するシートを、この媒体の背面に敷いて濃度を測定する。
グラフは各温度毎の濃度値をプロットした後、プロットした隣接点同士を直線で結ぶことにより完成される。作成されたグラフは通常、図２に示すように台形状となる。
【００７０】
これらのデータは、感熱層と支持体を合わせた該媒体の厚みや材質によって影響を受ける。
該媒体の厚みは、３００μｍ以下であれば厚みの影響は受けず、ほぼ同じデータが得られるが、それ以上の厚みの場合は、支持体側を削ったり、剥がしたりして厚みを３００μｍ以下にするか、厚みの厚い分を換算すればよい。
材質はポリマー主体ならばいずれでもよいが、金属等の場合は換算することが必要である。
このグラフから、上記の透明化上限温度や白濁化下限温度等を読み取り計算していく。
最初にこのグラフの中で最大濃度値（ＤＰＤ）を読み取る。次にｙ＝０．７×ＤＰＤ［の線を引き、この線より高濃度のプロット点を選択する。
このプロット点の数は５〜２０点が好ましい。
プロット点の数が少ないと、この後の計算結果が不確かなものとなる。
プロット点の数が少ない場合には、前述の熱傾斜試験機での加熱の温度間隔を狭くし、数を増やすことが必要である。
選択されたプロット点のうち、濃度値の大きいもの、濃度値の小さいものを各々同数だけ除外し、残ったものの濃度値を平均したものを平均透明濃度（ＤＷＤＹ）とする。
濃度値の大、小を除外する割合は選択されたプロット点のうち、各々１０〜３０％、好ましくは、１５〜２５％である。
このように濃度値が大きいものと小さいものを除外することにより、媒体の透明濃度の正確な値が算出できる。
【００７１】
次に、透明化下限濃度（ＤＷＰ）を、下記数式（１）により算出する。
ＤＷＰ＝ＤＷＤＹ−０．２×（ＤＷＤＹ−ＤＰＬＱ）（１）
ここでＤＰＬＱは最大白濁濃度であり、温度を上げていって、隣接した３点のプロット点が濃度値０．３以内になったとき、その３点の濃度の平均値から算出される。ＤＷＰはこの濃度以上であれば目視でほぼ透明に見える濃度を表わす。
さらに、グラフ上にｙ＝ＤＷＰの線を引き、濃度温度曲線との交点の温度を求める。この交点のうち、低温側を透明化下限温度（ＴＷＯ）、高温側を透明化上限温度（ＴＷＸ）とする。透明化温度幅（ΔＴＺ）は、下記数式（２）により求められる。
ΔＴｗ＝ＴＷＸ−ＴＷＯ （２）
【００７２】
また、白濁化上限濃度（Ｄｓ）は、下記数式（３）によって算出される。
Ｄｓ＝ＤＰＬＱ＋０．１×（ＤＷＤＹ−ＤＰＬＱ）（３）
グラフ上にｙ＝Ｄｓの線を引き、濃度−温度曲線の透明から白濁へと変化する部分との交点の温度を白濁化下限温度（ＴＶＯ）とする。
透明化上限温度と白濁化下限温度の差（ΔＴＷＶ）は、下記数式（４）で求められる。
ΔＴＷＶ＝ＴＶＯ−ＴＷＸ （４）
透明化開始濃度（ＤＷＤ）は、下記数式（５）で求められる。
ＤＷＤ＝ＤＰＬＱ＋０．２５×（ＤＷＤＹ−ＤＰＬＱ）（５）
透明化開始温度（ＴＷＤ）は、図２に示されるようにｙ＝ＤＷＶとグラフの交点から求められる。
【００７３】
透明化上限温度（ＴＷＸ）は、１１５℃以上であることが好ましい。
ＴＷＸが高温になることにより、画像耐久性を低下させることなく、透明化温度幅の拡大が可能となる。
透明化上限温度（ＴＷＸ）は１２０℃以上が好ましく、１２５℃以上がより好ましく、１３０℃以上がさらに好ましい。
この温度が高くなるほど印字感度が向上する。
また、ＴＷＸは１７０℃以下が好ましく、１６０℃以下がより好ましく、１５０℃以下がさらに好ましい。
この温度が低いほど印字感度が向上する。
透明化上限温度と白濁化下限温度の差（ΔＴＷＶ）は、２０℃以下であることが好ましい。
ＴＷＶがこれより大きくなると、白濁になる温度が必要以上に高くなるため、白濁画像を形成する際、非常に高いエネルギーが必要となり、画像の形成と消去を繰り返すと媒体表面に傷がついたり、画像の白濁度が低下してしまうので望ましくない。
ΔＴＷＶは１５℃以下が好ましく、１０℃以下がより好ましい。
【００７４】
透明化開始温度（ＴＷＤ）は、９５℃未満が好ましく、９０℃以下がより好ましく、８５℃以下がさらに好ましい。
また、ＴＷＤは、７０℃以上が好ましく、７５℃以上がより好ましい。
この温度が低いと消去性が向上し、高いと画像耐熱性が向上する。
透明化温度幅（ΔＴＺ）は３０℃以上であることが好ましい。
ΔＴＺがこれより小さくなると消去性が低下する。
透明化温度幅（ΔＴＺ）は、４０℃以上がより好ましく、４５℃以上がさらに好ましく、５０℃以上がより特に好ましい。
この温度幅が広い方が消去性が向上する。
また、ΔＴＺは１００℃以下が好ましく、９０℃以下がより好ましく、８０℃以下がさらに好ましい。
特に、透明化温度幅（ΔＴＺ）がより広くなると消去の際の処理速度が速くなっても均一な消去が可能になるという利点がある。
この場合のΔＴＺは６０℃以上が好ましく、７０℃以上がより好ましい。特に、透明化温度幅（ΔＴＺ）がより広くなると消去の際の処理速度が速くなっても均一な消去が可能になるという利点がある。
この場合のΔＴＺは、６０℃以上が好ましく、７０℃以上がより好ましい。
【００７５】
支持体としては、特に限定されないが、ポリエステル、ポリ塩化ビニル、ポリイミド等の合成樹脂からなるフィルム状物あるいは板状物、さらにこれらの物上にアルミニウム等の金属を蒸着した金属蒸着フィルム等が挙げられる。
感熱層に使用される母材としての樹脂は、有機低分子物質を均一に分散保持した層を形成すると共に、最大透明時の透明度に影響を与える材料である。
このため樹脂母材は透明性が良く、機械的に安定でかつ成膜性の良い樹脂が好ましい。
この樹脂は、そのガラス転移温度が５０℃以上のものが好ましく、６０℃以上がより好ましく、７０℃以上がさらに好ましい。
また、ガラス転移温度が１００℃未満が好ましく、９０℃未満がより好ましい。
ガラス転移温度が低すぎると画像耐熱性が低下し、高すぎると消去性が低下するので望ましくない。
【００７６】
この樹脂は、ゲル分率が３０％以上が好ましく、５０％以上がより好ましく、７０％以上がさらに好ましく、８０％以上がより特に好ましい。
ここにゲル分率とは、溶媒中で樹脂溶質が相互作用により独立運動性を喪失して集合し個化した状態（ゲル）を生じるときのそのゲルの生成比率をいう。
ゲル分率が小さいと繰り返し耐久性が低下するので、ゲル分率を向上させるには、樹脂中に熱、ＵＶ、ＥＢ等によって硬化する硬化性樹脂を混合するか、樹脂自身を架橋すれよい。
【００７７】
ゲル分率測定方法としては、支持体より膜を剥離してその膜の初期重量を測定し、その後に膜を４００メッシュ金網に挾んで、架橋前の樹脂が可溶な溶剤中に２４時間浸してから真空乾燥して、乾燥後の重量を測定する。
ゲル分率計算は、下記式によって行なう。
ゲル分率（％）＝［乾燥後重量（ｇ）／初期重量（ｇ）］×１００
この計算でゲル分率を算出するときに、感熱層中の樹脂成分以外の有機低分子物質粒子等の重量を除いて計算を行なう。
この際、予め有機低分子物質重量が分からないときには、ＴＥＭ、ＳＥＭ等の断面観察により、単位面積あたりに占める面積比率と樹脂と有機低分子物質のそれぞれの比重により重量比率を求めて、有機低分子物質重量を算出して、ゲル分率値を算出すればよい。
【００７８】
また、上記測定の際に、支持体上に可逆性感熱層が設けられており、その上に保護層等の他の層が積層されている場合や、支持体と感熱層の間に他の層がある場合には、上記したように、まず上記したＴＥＭ、ＳＥＭ等の断面観察により可逆性感熱層及びその他の層の膜厚を調べておき、その他の層の膜厚分の表面を削り、可逆性感熱層表面を露出させると共に、可逆性感熱層を剥離して前記測定方法と同様にゲル分率測定を行なえばよい。
また、この方法において感熱層上層に紫外線硬化樹脂等からなる保護層等がある場合には、この層が混入するのを極力防ぐために、保護層分の膜厚分を削ると共に感熱層表面も少し削りゲル分率値への影響を防ぐ必要がある。
【００７９】
この樹脂は架橋されることが好ましく、架橋すると該熱記録媒体は、印字と消去を繰り返しても感熱層内部の構造が変化しにくく、白濁度、透明度の低下がない等、繰り返し耐久性が向上する。
架橋する場合には樹脂中にヒドロキシル基、カルボキシル基、エポキシ基、アクリロイル基、メタクロイル基等の官能基を有することが好ましい。
架橋の方法としては、熱架橋、ＵＶやＥＢの照射による方法があり、イソシアネート化合物や官能性アクリル又はメタクリルモノマー等の架橋剤を添加し架橋することが好ましい。
【００８０】
このような樹脂としては、ポリ塩化ビニル、塩化ビニル−酢酸ビニル共重合体、塩化ビニル−酢酸ビニル−ビニルアルコール共重合体、塩化ビニル−酢酸ビニル−マレイン酸共重合体、塩化ビニル−アクリレート共重合体等の塩化ビニル系共重合体；ポリ塩化ビニリデン、塩化ビニリデン−塩化ビニル共重合体、塩化ビニリデン−アクリロニトリル共重合体等の塩化ビニリデン系共重合体；ポリエステル；ポリアミド；ポリアクリレートもしくはポリメタクリレート又はアクリレート−メタクリレート共重合体；シリコーン樹脂等が挙げられる。
これらの樹脂は、単独で用いてもよく、２種以上混合して用いてもよい。
【００８１】
ヒドロキシル基を有する熱可塑性樹脂とイソシアネート化合物の組み合わせの場合には、イソシアネート化合物は鎖式イソシアネート化合物と環式イソシアネート化合物を混合して用いることが好ましい。
鎖式イソシアネート化合物のみを用いた場合には、架橋された樹脂は通常柔軟になり消去性は向上するが、感熱層が柔らかすぎると繰り返し耐久性や画像耐熱性が低下するという欠点がある。
逆に、環式イソシアネート化合物のみを用いた場合には、架橋された樹脂は剛直になり繰り返し耐久性や画像耐熱性は向上するが、消去性が低下するという欠点がある。
鎖式イソシアネート化合物と環式イソシアネート化合物を混合して用いることにより、消去性と耐久性、耐熱性を両立させることが可能になる。
鎖式イソシアネート化合物と環式イソシアネート化合物の混合比は、重量比で９０：１０〜１０：９０であることが好ましく、９０：１０〜３０：７０がより好ましく、８０：２０〜３０：７０がさらに好ましい。
鎖式イソシアネート化合物が多いほど消去率や最大消去傾斜が向上し、ひいては、コントラストの向上が可能になる。
【００８２】
鎖式イソシアネート化合物としては、例えば、トリオール等の水酸基を有する鎖式化合物とヘキサメチレンジイソシアネートなどの脂肪族系のイソシアネートを直接もしくは単数または複数のエチレンオキサイドやプロピレンオキサイドを介して反応させたものが挙げられる。
鎖式イソシアネート化合物の分子量は５００以上が好ましく、７００以上がより好ましく、１０００以上がさら好ましい。
また、５０００以下が好ましく、４０００以下がより好ましく、３０００以下がさらに好ましい。
分子量が小さすぎると、架橋された塗膜が柔軟な構造をとりにくくなるため消去性が低下し、分子量が大きすぎると分子が動きにくくなるため架橋度が低下し耐久性が低下する。
【００８３】
１つのイソシアネート基当たりの分子量は、２５０以上が好ましく、３００以上がより好ましく、４００以上がさらに好ましい。
また、２０００以下が好ましく、１５００以下がより好ましく、１０００以下がさらに好ましい。
１つのイソシアネート基当たりの分子量が小さすぎると、架橋された塗膜が柔軟な構造をとりにくくなるため消去性が低下し、分子量が大きすぎると、分子が動きにくくなるため架橋度が低下し耐久性が低下する。
【００８４】
環式イソシアネート化合物とは、ベンゼン環又はイソシアヌレート環を有するイソシアネート化合物である。
この中でもイソシアヌレート環を有するタイプは、黄変がないため好適に用いられる。
環式イソシアネート化合物も環状構造以外にアルキレン鎖等の鎖状構造を有することが好ましい。
環式イソシアネート化合物の分子量は、１００以上が好ましく、２００以上がより好ましく、３００以上がさらに好ましい。また、１０００未満が好ましく、７００未満がより好ましい。
この分子量が小さすぎると、塗膜形成時の加熱によって蒸発して塗膜が架橋できなくなり耐久性が低下し、分子量が大きすぎると剛直な構造が形成できなくなり耐久性が低下する。鎖式イソシアネート化合物と環式イソシアネート化合物の混合物は、上記の材料を混合して用いてもよく、混合された商品を用いてもよい。
混合物の商品としては、例えば、日本ポリウレタン社製「コロネート２２９８−９０Ｔ」等があるが、これらに限定されるものではない。
【００８５】
本発明の熱可逆記録媒体の感熱層の厚さは、１〜３０μｍが好ましく、２〜２０μｍがより好ましく、４〜１５μｍがさらに好ましい。記録層が厚すぎると、層内での熱の分布が発生し均一に透明化することが困難となる。また、感熱層が薄すぎると、白濁度が低下し、コントラストが低くなる。
なお、記録層中の脂肪酸の量を増加させ、また、感熱層中の樹脂を架橋することにより、白濁度を増すことができる。
【００８６】
感熱層中の有機低分子物質と樹脂との割合は、重量比で２：１〜１：１６程度が好ましく、１：２〜１：８がより好ましく、１：２〜１：５が特に好ましく、１：２〜１：４がより特に好ましい。
１：２．５〜１：４が最も好ましい割合である。
樹脂の比率が上記以下になると、有機低分子物質を樹脂中に保持した膜に形成することが困難となり、また上記以上になると、有機低分子物質の量が少ないため、不透明化が困難になる。
【００８７】
本発明においては、感熱層上に感熱層を保護するために保護層を設けることができる。
この保護層の厚さは、０．１〜５μｍが適当であり、その材料の例としては、特開昭６３−２２１０８７号公報に記載されるようなシリコーン系ゴムあるいはシリコーン樹脂、特開昭６３−３１７３８５号公報に記載されるようなポリシロキサングラフトポリマー、特開平０２−５６６号公報に記載されるような紫外線硬化樹脂又は電子線硬化樹脂等を挙げることができる。
さらに保護層には、有機又は無機のフィラーを含有させることができる。
【００８８】
また、保護層形成液の溶剤やモノマー成分等から感熱層を保護するために、特開平１−１３３７８１号公報に記載されるように保護層と感熱層との間に中間層を設けることができる。
中間層の材料としては、感熱層に用いる樹脂を挙げることができるが、その他に、熱硬化性樹脂、熱可塑性樹脂、ＵＶ硬化樹脂、ＥＢ硬化樹脂が使用可能である。このようなものとして、ポリエチレン、ポリプロピレン、ポリスチレン、ポリビニルアルコール、ポリビニルブチラール、ポリウレタン、飽和ポリエステル、不飽和ポリエステル、エポキシ樹脂、フェノール樹脂、ポリカーボネート、ポリアミド等が挙げられる。中間層の厚さとしては、０．１〜２μｍ程度が好ましく、０．１μｍ以上にすると保護層の効果が維持でき、２μｍを以下にすると熱感度が低下することがない。
【００８９】
さらに、支持体と感熱層の間等に、光を正反射する層を設けて、コントラストを向上させることもできる。この光反射層は通常アルミニウムなどの金属を蒸着等の方法で形成され、その厚さは１００〜１０００Å程度が好ましい。
【００９０】
本発明の熱可逆記録ラベルは、上述した熱可逆記録媒体を構成する支持体の感熱層を形成する面と反対の面に、接着剤層又は粘着剤層を設けたものである。
この熱可逆記録ラベルには、接着剤層又は粘着剤層を形成したもの（無剥離紙型）と、その接着剤層又は粘着剤層の下に剥離紙をつけるもの（剥離紙型）とがあり、接着剤層を構成する材料としては、ホットメルト型のものが通常用いられる。
【００９１】
接着剤層又は粘着剤層の材料は、一般的に用いられているものが使用可能である。例えば、ユリア樹脂、メラミン樹脂、フェノール樹脂、エポキシ樹脂、酢ビ系樹脂、酢酸ビニル−アクリル系共重合体、エチレン−酢酸ビニル共重合体、アクリル系樹脂、ポリビニルエーテル系樹脂、塩化ビニル−酢酸ビニル系共重合体、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、ポリアミド系樹脂、塩素化ポリオレフィン系樹脂、ポリビニルブチラール系樹脂、アクリル酸エステル系共重合体、メタクリル酸エステル系共重合体、天然ゴム、シアノアクリレート系樹脂、シリコン系樹脂等が挙げられるが、これらに限定されるものではない。
【００９２】
次に、情報記憶部と可逆表示部を有し、該可逆表示部として上述の熱可逆記録媒体を構成する感熱層から少なくともなるものが用いられた部材について説明する。
この情報記憶部と可逆表示部を有する部材の具体例としては、次のようなものを挙げることができる。
▲１▼情報記録部を有する部材の一部を熱可逆記録媒体の支持体として、感熱層を直接形成したもの。
▲２▼情報記録部を有する部材に、前記熱可逆記録媒体の支持体面を、接着したもの。
▲３▼情報記録部を有する部材に、前記熱可逆記録ラベルが接着剤層又は粘着剤層を介して、接着されたもの。
▲４▼前記熱可逆記録媒体に、情報記録部を設けたもの。
（▲４▼の場合、熱可逆記録媒体を構成する支持体として厚手のものを用いることが好ましい）
【００９３】
これら▲１▼〜▲４▼のいずれの場合でも、情報記憶部と可逆表示部のそれぞれの機能が発揮できるよう設定されることが必要であり、そうでありさえすれば情報記憶部の設定位置は限定されず、例えば熱可逆性記録媒体における支持体の感熱層を設けた面と反対側の面に設けることも、支持体と感熱層との間でも、あるいは感熱層上の一部に設けることもできる。
【００９４】
この情報記録部を有する部材として用いられるものは、特に限定されないが、一般的にはカード、ディスク、ディスクカートリッジ又はテープカセットをあり、これらの例として次のようなものを挙げることができる。
ＩＣカードや光カード等の厚手カード、フロッピーディスク、光磁気記録ディスク（ＭＤ）やＤＶＤ−ＲＡＭ等の記憶情報が書換可能なディスクを内蔵したディスクカートリッジ、ＣＤ−ＲＷ等のディスクカートリッジを用いないディスク、ＣＤ−Ｒ等の追記型ディスク、ビデオテープカセット、等この可逆表示部と情報記憶部の双方を有する部材は、例えばカードの場合で説明すると、情報記憶部に記憶された情報の一部を感熱層に表示することによって、カード所有者等は、特別な装置がなくてもカードを見るのみで情報を確認することができて、熱可逆記録媒体を適用しないカードに比べてその利便性が非常に向上することになる。
【００９５】
情報記憶部は、必要な情報を記憶できるものでありさえすれば特に限定されないが、例えば、磁気記録、接触型ＩＣ、非接触型ＩＣあるいは光メモリが有用である。
磁気記録層は、通常用いられる酸化鉄、バリウムフェライト等のような金属化合物及び塩ビ系、ウレタン系及びナイロン系のような樹脂等を用いて支持体に塗工形成するか、または樹脂を用いず前記の金属化合物を用いて蒸着、スパッタリング等の方法により形成される。
また、表示に用いる熱可逆記録媒体を感熱層をバーコード、２次元コード等のような
やり方で記憶部として用いることもできる。
【００９６】
前記▲３▼の熱可逆記録ラベルを用いる例として、磁気ストライプ付塩化ビニル製カード等のように、支持体として感熱層の塗布が困難な厚手のもの場合には、その全面又は一部に接着剤層又は粘着剤層を設けることができる。こうすることによって、磁気に記憶された情報の一部を表示することができる等、この媒体の利便を向上できる。
この接着剤層又は粘着剤層を設けた熱可逆記録ラベルとしては、上記の磁気付塩ビカードだけでなく、ＩＣカードや光カード等の厚手カードにも適用できる。
【００９７】
また、この熱可逆記録ラベルは、フロッピーディスク、ＭＤやＤＶＤ−ＲＡＭ等の記憶情報が書換可能なディスクを内蔵したディスクカートリッジ上の表示ラベルの代わりとして用いることができる。
図３に、熱可逆記録ラベルをＭＤのディスクカートリッジ上に貼った例を示す。
さらに、ＣＤ−ＲＷ等のディスクカートリッジを用いないディスクの場合には、直接ディスクに熱可逆記録ラベルを貼ることや、直接ディスク上に感熱層を設けることもできる。
このようにして、それらの記憶内容の変更に応じて自動的に表示内容を変更する等の用途への応用が可能である。
図４に、熱可逆記録ラベルをＣＤ−ＲＷ上に貼った例を示す。
【００９８】
本発明の熱可逆記録ラベルは、ＣＤ−Ｒなどの追記型ディスク上に熱可逆記録ラベルを貼って、ＣＤ−Ｒに追記した記憶情報の一部を書換え表示することも可能である。
図５は、ＡｇＩｎＳｂＴｅ系の相変化形記憶材料を用いた光情報記録媒体（ＣＤ−ＲＷ）上に熱可逆記録ラベルを形成した構成の例である。基本的な構成は、案内溝を有する基体上に第一誘電体層、光情報記憶層、第二誘電体層、反射放熱層、中間層が設けられ、基体の裏面にハードコート層を有する。さらに、中間層上に熱可逆記録ラベルが貼付されている。
誘電体層は必ずしも記録層の両側に設ける必要はないが、基体がポリカーボネート樹脂のように耐熱性が低い材料の場合には、第一誘電体層を設けることが望ましい。
【００９９】
さらに、図６に示すように、ビデオテープカセットの表示ラベルとして用いてもよい。
厚手カード、ディスクカートリッジ、ディスク上に熱可逆記録機能を設ける方法としては、上記の熱可逆記録ラベルを貼る方法以外に、それらの上に感熱層を直接塗布する方法や、予め別の支持体上に感熱層を形成しておき、厚手カード、ディスクカートリッジ、ディスク上に感熱層を転写する方法等がある。
転写する場合には、感熱層上にホットメルトタイプ等の接着層や粘着層を設けておいてもよい。
厚手カード、ディスク、ディスクカートリッジ、テープカセット等のように剛直なものの上に熱可逆記録ラベルを貼着したり、感熱層を設ける場合には、サーマルヘッドとの接触性を向上させ、画像を均一に形成するために弾力があり、クッションとなる層又はシートを、剛直な基体とラベル又は感熱層の間に設けることが好ましい。
【０１００】
例えば、本発明の可逆性感熱記録媒体は、図７ａに示されるように、支持体（１１）上に、可逆性感熱記録層（１３）、保護層（１４）を設けてなるフィルム、図７ｂに示されるように、支持体（１１）上に、アルミ反射層（１２）、可逆性感熱記録層（１３）、保護層（１４）を設けてなるフィルム、図７ｃに示されるように、支持体（１１）上に、アルミ反射層（１２）、可逆性感熱記録層（１３）、保護層（１４）を設け支持体（１１）の裏面に磁気記録層（１６）を設けてなるフィルム、を図８に示されるように、印刷表示部（２３）を有するカード（２１）に加工した形態とすることがでる。
【０１０１】
さらに、例えば、図９ａに示されるように、支持体（１１）上に、アルミ反射層（１２）、可逆性感熱記録層（１３）、保護層（１４）を設けてなるフィルムをカード状に加工し、ＩＣチップを納める窪み部（２３）を形成するとともにカード状に加工した形態とすることができる。
この例においては、カード状の可逆性感熱記録媒体に書き換え記録部（２４）がラベル加工されると共に、可逆性感熱記録媒体の裏面側には所定箇所にＩＣチップ埋め込み用窪み部（２３）が形成されており、この窪み部（２３）に、図９ｂに示されるようなウェハ（２３１）が組込まれて固定される。
ウェハ（２３１）は、ウェハ基板（２３２）上に集積回路（２３３）が設けられると共に、この集積回路（２３３）に電気的に接続されている複数の接触端子（２３４）がウェハ基板（２３２）に設けられる。
この接触端子（２３４）は、ウェハ基板（２３２）の裏面側に露出しており、専用のプリンタ（リーダライタ）がこの接触端子（２３４）に電気的に接触して所定の情報を読み出したり書き換えたりできるように構成されている。
【０１０２】
この可逆的感熱記録カードの機能例を、図１０を参照しつつ説明する。
図１０（ａ）は、集積回路（２３３）を示す概略の構成ブロック図であり、（ｂ）はＲＡＭの記憶データの１例を示す構成ブロック図である。
集積回路（２３３）は、例えば、ＬＳＩで構成されており、その中には制御動作を所定の手順で実行することのできるＣＰＵ（２３５）と、ＣＰＵ（２３５）の動作プログラムデータを格納するＲＯＭ（２３６）と、必要なデータの書き込み及び読み出しができるＲＡＭ（２３７）を含む。
さらに集積回路（２３３）は、入力信号を受けてＣＰＵ（２３５）に入力データを与えるとともにＣＰＵ（２３５）からの出力信号を受けて外部に出力する入出力インターフェース（２３８）と、図示していないが、パワーオンリセット回路、クロック発生回路、パルス分周回路（割込パルス発生回路）、アドレスデコーダ回路とを含む。
【０１０３】
ＣＰＵ（２３５）は、パルス分周回路から定期的に与えられる割込パルスに応じて、割込制御ルーチンの動作を実行することが可能となる。
また、アドレスデコード回路はＣＰＵ（２３５）からのアドレスデータをデコードし、ＲＯＭ（２３６）、ＲＡＭ（２３７）、入出力インターフェース（２３８）にそれぞれ信号を与える。
入出力インターフェース（２３８）には、複数（図中では８個）の接触端子（２３４）が接続されており、上記の専用プリンタ（リーダライタ）からの所定データがこの接触端子（２３４）から入出力インターフェース（２３８）を介してＣＰＵ（２３５）に入力される。ＣＰＵ（２３５）は、入力信号に応答して、かつＲＯＭ（２３６）内に格納されたプログラムデータに従って、各動作を行い、かつ、所定のデータ、信号を入出力インターフェース（２３８）を介してカードリーダライタに出力するものである。
【０１０４】
図１０（ｂ）に示されるように、ＲＡＭ（２３７）は複数の記憶領域（２３９ａ）〜（２３９ｆ）を含む。
例えば、領域（２３９ａ）にはカード番号が記憶され、（２３９ｂ）には例えば、カード所有者の氏名、住所、電話番号等のＩＤデータが記憶され、領域（２３９ｃ）には例えば、所有者の使用しうる残存有価価値又は有価物に相当する情報が記憶され、領域（２３９ｄ）（２３９ｅ）（２３９ｆ）及び（２３９ｇ）には使用済の有価価値又は有価物に相当する情報が記憶される。
【０１０５】
本発明は、さらに、上記熱可逆記録媒体、上記情報記憶部を有する部材又は上記ラベルを用い、加熱により画像の形成及び／又は消去を行うことを特徴とする画像処理方法及び上記熱可逆記録媒体、上記情報記憶部を有する部材又は上記ラベルを有し、加熱により画像の形成及び／又は消去を行うことを特徴とする画像処理装置を提供する。
【０１０６】
画像の形成は、サーマルヘッド、レーザ等、該媒体を画像上に部分的に加熱可能である画像記録手段が用いられる。
画像の消去は、ホットスタンプ、セラミックヒータ、ヒートローラ、熱風等や、サーマルヘッド、レーザ等の画像消去手段が用いられる。
この中でも、セラミックヒータが好ましく用いられる。セラミックヒータを用いることにより、装置が小型化でき、かつ安定した消去状態が得られ、コントラストのよい画像が得られる。
セラミックヒータの設定温度は、１００℃以上が好ましく、１１０℃以上がより好ましく、１１５℃以上がさらに好ましい。
また、画像消去手段としてサーマルヘッドを用いることにより、さらに装置全体の小型化が可能となる。
【０１０７】
さらに、消費電力を低減することが可能であり、バッテリー駆動のハンディタイプの装置も可能となる。
形成用と消去用を兼ねて一つのサーマルヘッドとすれば、さらに小型化が可能となる。
一つのサーマルヘッドで形成と消去を行なう場合、一度前の画像を全部消去した後、あらためて新しい画像を形成してもよく、画像毎にエネルギーを変えて一度に前の画像を消去し、新しい画像を形成していくオーバーライト方式も可能である。
オーバーライト方式では、形成と消去を合わせた時間が少なくなり、記録のスピードアップにつながる。
感熱層と情報記憶部を有するカードを用いる場合、上記の装置には、情報記憶部の記憶を読み取る手段と書き換える手段も含まれる。
【０１０８】
図１１に、本発明の画像処理装置の例を示す。図１１は、本発明により画像の消去をセラミックヒータで、画像の形成をサーマルヘッドでそれぞれ行う場合の装置の概略例を示す。
図１１の画像処理装置においては、最初、記録媒体の磁気記録層に記憶された情報を磁気ヘッドで読み取り、次に、セラミックヒータで可逆性感熱層に記録された画像を加熱消去し、さらに、磁気ヘッドで読み取られた情報をもとにして、処理された新たな情報がサーマルヘッドにより、逆性感熱層に記録される。
その後、磁気記録層の情報も新たな情報に書き替えられる。
【０１０９】
すなわち、図１１の画像処理装置においては、感熱層の反対側に磁気記録層を設けた熱可逆性記録媒体（１）は往復の矢印で図示されている搬送路に沿って搬送され、又は搬送路に沿って装置内を逆方向に搬送される。
熱可逆性記録媒体（１）は、磁気ヘッド（３４）と搬送ローラ（３１）間で磁気記録層に磁気記録又は記録消去され、セラミックヒータ（３８）と搬送ローラ（４０）間で像消去のため加熱処理され、サーマルヘッド（５３）及び搬送ローラ（４７）間で像形成され、その後、装置外に搬出される。
ただし、磁気記録の書き替えは、ミックヒータによる画像消去の前であっても後であってもよい。
また、所望により、セラミックヒータ（３８）と搬送ローラ（４０）間を通過後、又はサーマルヘッド（５３）及び搬送ローラ（４７）間を通過後、搬送路を逆方向に搬送され、セラミックヒータ（３８）よる再度の熱処理、サーマルヘッド（５３）による再度の印字処理を施すことができる。
【０１１０】
以下、実施例を挙げて本発明をさらに詳しく説明するが、これら実施例によって本発明はなんら限定されるものではない。
【０１１１】
実施例１
大日本インキ工業社製磁気原反（メモリディック、ＤＳ−１７１１−１０４０：１８８μｍ厚さの透明ＰＥＴフィルム上に磁気記録層及びセルフクリーニング層を塗工したもの）のＰＥＴフィルム側に、約４００ÅのＡｌを真空蒸着して光反射層を設けた。
その上に、
塩化ビニル−酢酸ビニル−リン酸エステル共重合体 １０部
（電気化学工業社製、デンカビニール♯１０００Ｐ）
メチルエチルケトン ４５部
トルエン ４５部
からなる溶液を塗布、加熱乾燥し、約０．５μｍ厚さの接着層を設けた。
次に、塩化ビニル系共重合体（日本ゼオン社製、ＭＲ１１０）２６部をメチルエチルケトン２３０部に溶解した樹脂溶解液中に、
ベヘン酸ベヘニル（ミヨシ油脂社試作品） ６部
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃
（ミヨシ油脂社試作品） ４部
を加え、ガラス瓶中に直径２ｍｍのセラミックビーズを入れて、ペイントシェーカー（浅田鉄工（株）製）を用い、４８時間分散し、均一な分散液を調製した。
この分散液に、イソシアネート化合物（日本ポリウレタン社製、コロネート２２９８−９０Ｔ）４部を加え感熱層液を調製し、上記の磁気記録層を有するＰＥＴフィルムの接着層上に塗布、加熱乾燥した後、さらに６０℃環境下に７２時間保存し樹脂を架橋させ、約１０μｍ厚さの感熱層を設けた。
【０１１２】
この感熱層上に、
ウレタンアクリレート系紫外線硬化性樹脂７５％酢酸ブチル溶液
（大日本インキ化学工業社製、ユニディックＣ７−１５７） １０部
イソプロピルアルコール １０部
からなる溶液をワイヤーバーで塗布し、加熱乾燥後、８０ｗ／ｃｍの高圧水銀灯で紫外線を照射し、硬化させ、約３μｍ厚の保護層を設け、熱可逆記録媒体を作製した。
【０１１３】
実施例２
ベヘン酸ベヘニルを８部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を２部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【０１１４】
実施例３
ベヘン酸ベヘニルを９部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を１部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【０１１５】
実施例４
ベヘン酸ベヘニルを９．５部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を０．５部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【０１１６】
実施例５
ベヘン酸ベヘニルを、ジヘプタデシルケトン（日本化成（株）製、ワックスＫＳ）に代えた以外は、実施例２と同様にして熱可逆記録媒体を作製した。
【０１１７】
実施例６
ベヘン酸ベヘニルを、エタノールアミンジステアレート（日本化成（株）製、スリエイドＳ）に代えた以外は、実施例２と同様にして熱可逆記録媒体を作製した。
【０１１８】
実施例７
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を、ＣＨ₃（ＣＨ₂)₁₆ＣＯＮＨＮＨＣＯ（ＣＨ₂)₁₆ＣＨ₃（ミヨシ油脂社試作品）に代えた以外は、実施例４と同様にして熱可逆記録媒体を作製した。
【０１１９】
実施例８
ベヘン酸ベヘニルを、ジヘプタデシルケトン（日本化成（株）製、ワックスＫＳ）に代えた以外は、実施例７と同様にして熱可逆記録媒体を作製した。
【０１２０】
実施例９
ベヘン酸ベヘニルを、エタノールアミンジステアレート（日本化成（株）製、スリエイドＳ）に代えた以外は、実施例７と同様にして熱可逆記録媒体を作製した。
【０１２１】
実施例１０
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を、ＣＨ₃（ＣＨ₂)₁₇ＯＯＣＮＨ（ＣＨ₂)₆ＮＨＣＯＯ（ＣＨ₂)₁₇ＣＨ₃（ミヨシ油脂社試作品）に代えた以外は、実施例４と同様にして熱可逆記録媒体を作製した。
【０１２２】
実施例１１
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＯ（ＣＨ₂)₄ＯＯＣＮＨ（ＣＨ₂)₁₇ＣＨ₃（ミヨシ油脂社試作品）に代えた以外は、実施例２と同様にして熱可逆記録媒体を作製した。
【０１２３】
実施例１２
ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を、ＣＨ₃(ＣＨ₂)₁₇ＳＯ₂(ＣＨ₂)₂ＳＯ₂(ＣＨ₂)₁₇ＣＨ₃（ミヨシ油脂社試作品）に代えた以外は、実施例４と同様にして熱可逆記録媒体を作製した。
【０１２４】
実施例１３
ＣＨ₃(ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を、下記の材料（ミヨシ油脂社試作品）に代えた以外は、実施例２と同様にして熱可逆記録媒体を作製した。
【化３０】

【０１２５】
実施例１４
約５０μｍ厚のＡｌ蒸着ポリエステルフィルム（東レ社製、♯５０メタルミー）のＡｌ蒸着面上に、実施例１と同様に接着層、感熱層、保護層を形成した。
さらに、支持体の感熱層面の裏面に、約５μｍのアクリル系粘着剤層を設け、熱可逆記録ラベルを作製した。
このラベルを、図４のようにドーナッツ状にして、図５のようにＣＤ−ＲＷ上に貼り合わせて、可逆表示機能付きの光情報記録媒体を作製した。
【０１２６】
上記のように作製した光情報記録媒体を用い、ＣＤ−ＲＷドライブ〔（株）リコー製、ＭＰ６２００Ｓ）で記憶した情報の一部（年月日、時刻等〕を、記録手段（サーマルヘッド）と消去手段（セラミックヒーター）を有する記録装置を用いて、サーマルヘッドの記録エネルギーをそれぞれの媒体の記録温度の変化に合わせて調整して感熱層へ表示記録し、可視化した。
また、該ドライブを用い、光情報記録媒体の記憶層の情報を書き換え、記録装置により消去手段を用い、先の記録を消去し新たにサーマルヘッドで、書き換えた情報を感熱層に書き換え、表示記録した。
さらに、この表示記録の書き換えを１００回繰り返したが、記録及び消去は可能であった。
【０１２７】
実施例１５
実施例１４の熱可逆記録ラベルを、図３に示すように、ミニディスク（ＭＤ）ディスクカートリッジ上に貼り付けた。
ＭＤに記憶された情報の一部（年月日、曲名等）を、記録手段（サーマルヘッド）と消去手段（セラミックヒーター）を有する記録装置を用いて、サーマルヘッドの記録エネルギーをそれぞれの媒体の記録温度の変化に合わせて調整して感熱層へ表示記録し、可視化した。
さらに、この表示記録の書き換えを１００回繰り返したが、記録及び消去は可能であった。
【０１２８】
比較例１
感熱層の塗工溶液を、下記のとおりとした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
ベヘン酸（ＳＩＧＭＡ社製試薬、純度９９％） ５部
エイコサン二酸（岡村製油社製、ＳＬ−２０−９０） ５部
塩化ビニル−酢酸ビニル共重合体 ３８部
（ユニオンカーバイト社製、ＶＹＨＨ）
テトラヒドロフラン ２１０部
トルエン ２０部
【０１２９】
比較例２
感熱層の塗工溶液を、下記のとおりとした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
ここで形成された感熱層は、白色の粒子が目立ち均一性の悪いものであった。
ベヘン酸ベヘニル（シグマ社製、試薬） ９．５部
エチレンビスベヘン酸アミド ０．５部
（日本化成社製、スリパックスＢ）
塩化ビニル−酢酸ビニル共重合体 ３０部
（ユニオンカーバイト社製、ＶＹＨＨ）
テトラヒドロフラン １６０部
【０１３０】
実施例１６
ベヘン酸ベヘニルを７部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３１】

【０１３１】
実施例１７
ベヘン酸ベヘニルを７部、ＣＨ₃(ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３２】

【０１３２】
実施例１８
ベヘン酸ベヘニルを７部、ＣＨ₃(ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３３】

【０１３３】
実施例１９
ベヘン酸ベヘニルを７部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３４】

【０１３４】
実施例２０
ベヘン酸ベヘニルを７部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３５】

【０１３５】
実施例２１
ベヘン酸ベヘニルを７部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物３部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
【化３６】

【０１３６】
実施例２２
ベヘン酸ベヘニルを、エタノールアミンジステアレート（日本化成（株）製、スリエイドＳ）とする以外は、実施例１６と同様にして熱可逆記録媒体を作成した。
【０１３７】
実施例２３
ベヘン酸ベヘニルを、ジヘプタデシルケトン（日本化成（株）製、ワックスＫＳ）とする以外は、実施例１６と同様にして熱可逆記録媒体を作成した。
【０１３８】
実施例２４
ベヘン酸ベヘニルを９部、ＣＨ₃（ＣＨ₂)₁₇ＮＨＣＯＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃を下記化合物２種をそれぞれ０．５部とした以外は、実施例１と同様にして熱可逆記録媒体を作製した。
ＣＨ₃ＣＨ₂Ｏ（ＣＨ₂)₃ＮＨＣＯ（ＣＨ₂)₁₁ＮＨＣＯＮＨ（ＣＨ₂)₁₇ＣＨ₃
【化３７】

【０１３９】
〔評価〕
このようにして作製した熱可逆記録媒体（実施例１〜１３、１６〜２４、比較例１、２）を用い、下記の評価を行った。
【０１４０】
コントラスト
上記のようにして得られた媒体をあらかじめ透明化しておき、九州松下電器製の印字消去機能付磁気カードリーダライタ（ＫＵ−Ｒ−３００１ＦＡ）を用いて、サーマルヘッドの印字エネルギー値を０．４７ｍＪ／ｄｏｔに設定して熱印加を行い、室温まで冷却して、マクベス反射濃度計で反射濃度測定を行い、これを初期画像濃度とした。
次に同じ装置を用いて、前記エネルギー値にて媒体に白濁画像を形成した後に、セラミックヒータの消去温度値を９０℃に設定して熱印加を行い、室温まで冷却して、マクベス反射濃度計で反射濃度測定を行い、これを初期消去濃度とした。
次に上記により求めた初期画像濃度、初期消去濃度により初期コントラスト（初期消去濃度−初期画像濃度）を算出した。
【０１４１】
（２）耐アンモニア性
あらかじめ透明化された媒体を炭酸アンモニウム８％水溶液中に４８時間浸漬した後に、前記のコントラストで用いた同じ装置、及び同じ方法にて画像濃度、消去濃度を測定し、これらを試験後画像濃度、試験後消去濃度とした。
次に上記により求めた試験後画像濃度、試験後消去濃度により試験後コントラスト（試験後消去濃度−試験後画像濃度）を算出した。
【０１４２】
（３）消去性
予め、該媒体を透明化しておき、九州松下電器製リーダライタ（ＫＵ−Ｒ−３００１ＦＡ）を用い、５℃環境下で、熱傾斜試験機で部分的に白濁化させた後、消去温度の中心近辺の最適消去温度で消去することを、５０枚行ない、画像の消去状態を視認して判定した。
評価レベル
○ ：すべて消去可能。
○〜△：薄い消し残りが少し発生。
△ ：消し残りが時々発生。
× ：消し残りが頻繁に発生。
（１）〜（３）の結果をまとめて表１に示す。
（４）透明化上限温度（Ｔｔｕ）、不透明（白濁）化下限温度（Ｔｓｌ）、透明化上限温度と白濁化下限温度の温度差（ΔＴｔｓ）、透明化下限温度（Ｔｔｌ）、透明化温度幅（ΔＴｗ）
前記した測定方法を用いて、Ｔｔｕ、Ｔｓｌ、ΔＴｔｓ、Ｔｔｌ、ΔＴｗを測定した。結果をまとめて表３、４に示す。
【０１４３】
【表１】

【０１４４】
【表２】

【０１４５】
【表３】

【０１４６】
【表４】

【０１４７】
【発明の効果】
本発明によれば、塩基性物質の存在下に保存されても充分な白濁度が得られ、透明化する温度幅を広げ、環境温度が変化しても充分な画像消去性及び高コントラストの画像が得られ、充分な白濁度が得られる熱可逆性記録媒体、情報記憶部を有する部材、画像処理方法及び画像処理装置が提供され、熱可逆性記録分野に寄与するところはきわめて多大である。
【図面の簡単な説明】
【図１】本発明に係る熱可逆記録媒体による透明度の変化を表した図である。
【図２】本発明に係る熱可逆記録媒体の透明化上限温度、白濁化下限温度、透明化開始温度、透明化温度幅を説明する図である。
【図３】熱可逆記録ラベルを、ＭＤのディスクカートリッジに貼付した例を示す図である。
【図４】熱可逆記録ラベルを、ＣＤ−ＲＷ上に貼付した例を示す図である。
【図５】ＡｇＩｎＳｂＴｅ系の相変化形記憶材料を用いた光情報記録媒体（ＣＤ−ＲＷ）上に、熱可逆記録ラベルを形成した例を示す図である。
【図６】ビデオテープカセットの表示ラベルを示す図である。
【図７】本発明に係る熱可逆記録媒体の層構成例を示す図である。
【図８】本発明に係る熱可逆記録媒体の１例を示す図である。
【図９】本発明に係る熱可逆記録媒体の別の１例を示す図である。
【図１０】本発明に係る熱可逆記録媒体の使用例を示す図である。
【図１１】本発明に係る熱可逆記録装置の１例を示す図である。
【符号の説明】
１ 熱可逆性記録媒体
１１ 支持体
１２ アルミニウム反射層
１３ 感可逆性記録層
１４ 保護層
１５ 透明ＰＥＴフイルム
１６ 空気層
１７ 接着層
２０ 磁気塗工層
２１ カード
２２ 書き換え記録部
２３ ＩＣチップ用窪み部
２４ 書き換え記録部のラベル加工
３４ 磁気ヘッド
３８ セラミックヒータ
４０ 搬送ローラ
４７ 搬送ローラ
５３ サーマルヘッド
２３１ ウエハ
２３２ ウエハ基板
２３３ 集積回路
２３４ 接触端子
２３５ ＣＰＵ
２３６ ＲＯＭ
２３７ ＲＡＭ
２３８ 入出力用インターフェース
２３９ ＲＡＭ記憶領域の情報[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermoreversible recording medium, a thermoreversible recording label, and information capable of repeatedly forming and erasing an image using a thermosensitive layer that reversibly changes between a transparent state and an opaque state depending on temperature. The present invention relates to a member having a storage unit, an image processing method and an image processing apparatus using them.
[0002]
[Prior art]
In recent years, a thermoreversible recording medium having a thermosensitive layer that can perform temporary image display and can erase the image when it is no longer needed, and has a thermosensitive layer whose transparency reversibly changes depending on temperature, has attracted attention. .
Typical examples thereof include organic low molecular weight substances such as higher fatty acids in a resin matrix such as vinyl chloride-vinyl acetate copolymer as disclosed in JP-A-55-154198. Dispersed thermoreversible recording media are known.
However, this thermoreversible recording medium has a narrow temperature range of 2 to 4 ° C. exhibiting translucency and transparency, and is used for erasing and forming an image using translucency, transparency, shading, and cloudiness. There was a drawback that temperature control was difficult.
[0003]
As a method for expanding the transparent temperature range, for example, JP-A-2-1363, JP-A-3-2089, JP-A-4-366682, or JP-A-6-255247 discloses higher fatty acids, higher ketones or It has been proposed to use a mixture of a fatty acid ester and an aliphatic dicarboxylic acid.
By these methods, the temperature range that becomes transparent can be expanded, and the image can be easily erased (transparent).
[0004]
By the way, these thermoreversible recording media are often used for applications such as point cards, and since point cards are repeatedly used over a long period of time, they are stored under various conditions or environments.
When the card is stored, if a basic substance such as ammonia or amine is present in the environment, there is a problem that a cloudy image cannot be formed even if the amount of the substance is extremely small.
The cause is thought to be because the carboxyl group of the organic low molecular weight substance and the basic substance form a salt to increase the melting point of the organic low molecular weight substance.
[0005]
JP-A-5-294062 also proposes to use a higher ketone or fatty acid ester and a saturated aliphatic bisamide in a mixed manner to widen the transparent temperature range.
These do not use a low molecular weight organic substance having a carboxyl group, so that there is little influence of a basic substance, and the range of the clearing temperature is slightly widened, and the erasability is improved, but there is a disadvantage that the contrast is low. .
[0006]
Further, JP-A-11-58988 uses a low melting point organic low molecular weight substance such as a fatty acid ester, a fatty acid metal salt such as copper stearate, a fatty acid amide, or the like in order to reduce the influence of a basic substance. Has been proposed.
However, these are less affected by basic substances, but when copper stearate is used, the material is colored blue, so the medium is also colored blue, When amide is used, since the melting point of fatty acid amide is not so high, there is a drawback that the clearing temperature range is narrow and it is difficult to erase (clear) the image.
[0007]
[Problems to be solved by the invention]
A first object of the present invention is to provide a thermoreversible recording medium capable of obtaining a sufficient turbidity even when stored in the presence of a basic substance.
A second object of the present invention is to provide a thermoreversible recording medium that has a wide temperature range for transparency and that can provide good image erasability and a high-contrast image even when the ambient temperature changes.
A third subject of the present invention is a thermoreversible recording label applying a thermoreversible recording medium which is a means for solving the first and second problems, a member having an information storage unit, an image processing method and an image processing using them To provide an apparatus.
[0008]
[Means for Solving the Problems]
As a result of intensive studies focusing on the organic low molecular weight substance blended in the heat-sensitive layer, the present inventors have found that the above-mentioned problem can be achieved by using a specific linear hydrocarbon-containing compound having no carboxyl group. Based on this finding, the present invention has been completed.
[0009]
  That is, according to the present invention, firstly, a heat provided with a heat-sensitive layer on which a resin and an organic low-molecular substance are main components and a transparent state and an opaque state reversibly change depending on temperature is provided. Reversible recording medium, the organic low-molecular substance is1) -7)And a linear hydrocarbon-containing compound (A) having no carboxyl group, which is selected from the compounds described in 1), is provided.
1)A straight-chain hydrocarbon-containing compound having a urethane bond.
2)A linear hydrocarbon-containing compound having a sulfonyl bond.
3)A linear hydrocarbon-containing compound having an oxalic acid diamide bond.
4)A linear hydrocarbon-containing compound having a diacyl hydrazide bond.
5)A linear hydrocarbon-containing aliphatic compound having a urea bond and a urethane bond.
6)A linear hydrocarbon-containing aliphatic compound having a urea bond and an amide bond.
7)A linear hydrocarbon-containing aliphatic compound having a plurality of urea bonds.
[0010]
  The first invention includes the thermoreversible recording medium described in the following (1) to (11).
(1) Of the straight chain hydrocarbon-containing compound (A),1) to 7)Has at least one selected from a phenylene structure, a cyclohexylene structure, a cyclohexyl group, a phenyl group and a heterocyclic ring.
(2) A thermoreversible recording medium in which at least one of the molecular ends of the linear hydrocarbon-containing compound (A) is a methyl group.
(3) A thermoreversible recording medium in which the linear hydrocarbon-containing compound (A) has a melting point of 100 ° C. or higher.
(4) As the organic low molecular weight substance, the linear hydrocarbon-containing compound (B) having a melting point lower by 20 ° C. or more than the melting point of the linear hydrocarbon-containing compound (A) and having no carboxyl group A thermoreversible recording medium using at least one kind.
(5) A thermoreversible recording medium in which the total number of carbon atoms of the linear hydrocarbon-containing compound (A) and the linear hydrocarbon-containing compound (B) is 6 to 60.
(6) A thermoreversible recording medium in which the linear hydrocarbon-containing compound (B) has a melting point of 50 ° C or higher and lower than 100 ° C.
(7) A thermoreversible recording medium in which a mixing ratio of the linear hydrocarbon-containing compound (A) and the linear hydrocarbon-containing compound (B) is 80:20 to 1:99 by weight.
(8) The linear hydrocarbon-containing compound (B) is at least one selected from fatty acid esters, ketones having alkyl groups, dibasic acid esters, alcohol difatty acid esters, aliphatic monoamide compounds, and aliphatic monourea compounds. A thermoreversible recording medium.
(9) A thermoreversible recording medium that satisfies all of the following three conditions (i) to (iii) for reversibly changing the transparent state and the opaque state depending on the temperature.
(I) The transparent upper limit temperature is 115 ° C. or higher.
(Ii) The temperature difference between the transparency upper limit temperature and the opacification lower limit temperature is 20 ° C. or less.
(Iii) The transparent temperature range is 30 ° C. or higher.
(10) A thermoreversible recording medium in which the gel fraction of the resin is 30% or more.
(11) A thermoreversible recording medium in which at least a part of the resin is crosslinked.
[0011]
According to the present invention, secondly, the heat is characterized in that an adhesive layer or a pressure-sensitive adhesive layer is provided on the surface opposite to the surface on which the heat-sensitive layer of the support constituting the thermoreversible recording medium is formed. A reversible recording label is provided.
[0012]
According to the present invention, thirdly, an information recording unit comprising an information storage unit and a reversible display unit, wherein the reversible display unit comprises at least a heat-sensitive layer constituting the thermoreversible recording medium. A member is provided.
[0013]
The third invention includes the members described in the following (1) to (3).
(1) A member having an information recording part provided with a reversible display part.
(2) A member having an information storage unit in which the member having the information storage unit is a card, a disk, a disk cartridge, or a tape cassette.
(3) A member having an information storage unit provided with a reversible display unit using the thermoreversible recording label.
[0014]
According to the present invention, fourthly, an image is formed and / or erased by heating a thermosensitive layer constituting each of the thermoreversible recording medium, the thermoreversible recording label, or the member having the information storage unit. An image processing method is provided.
[0015]
The fourth invention includes an image processing method for forming an image using a thermal head and an image processing method for erasing an image using a thermal head or a ceramic heater.
[0016]
According to the present invention, fifthly, the thermoreversible recording medium, the thermoreversible recording label, or the member having the information storage unit is mounted, and a means for forming and / or erasing an image is provided. An image processing apparatus is provided.
[0017]
The fifth invention includes an image processing apparatus in which the image forming means is a thermal head and an image processing apparatus in which the image erasing means is a thermal head or a ceramic heater.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
First, the thermoreversible mechanism of the recording medium of the present invention will be described.
The thermoreversible recording medium of the present invention is provided with a heat-sensitive layer on a support that reversibly changes between a transparent state and an opaque state (also referred to as a cloudy state) depending on temperature. The opaque state is assumed to be formed by the following mechanism.
In other words, in the transparent state, the particles of organic low molecular weight substance dispersed in the resin, which is the base material, and the resin are in close contact with each other, and there are no voids in the particle portion, so light incident from one side is scattered. The transparent state is considered to be transparent because it penetrates to the opposite side, and the non-transparent state is composed of polycrystals in which fine particles of organic low-molecular substances are aggregated. It is considered that light incident from one side appears to be white because it is refracted and scattered at the interface between the void and the crystal and between the void and the resin.
[0019]
FIG. 1 is a diagram for explaining an example of a temperature-transparency change of the thermoreversible recording medium of the present invention.
In FIG. 1, a heat-sensitive layer mainly composed of a resin and an organic low molecular weight substance dispersed in the resin is, for example, T₀It is in an opaque state at the following normal temperature. As this is heated, the temperature T₁Gradually begins to become transparent from the temperature T₂~ T_ThreeWhen it is heated to transparent, it becomes transparent.₀It remains transparent even when returned to the normal temperature below.
This is the temperature T₁As the resin begins to soften from the vicinity and the softening proceeds, the resin shrinks, for example, to reduce the interface between the resin and the organic low-molecular-weight material particles or the voids in the particles.₂~ T_ThreeThen, the organic low molecular weight material becomes semi-molten and becomes transparent by filling the remaining void with molten organic low molecular weight material, and it cools with the seed crystal remaining and crystallizes at a relatively high temperature. This is probably because the resin follows the volume change of the particles accompanying crystallization because the resin is still in a softened state, so that voids are not formed and the transparent state is maintained.
[0020]
T_FourWhen heated to the above temperature, a translucent state intermediate between maximum transparency and maximum opacity is achieved.
Next, when this temperature is lowered, the first cloudy opaque state is restored without taking the transparent state again.
This is the temperature T_FourAfter the organic low molecular weight material is completely melted as described above, it becomes supercooled and T₀This is probably because crystallization occurs at a slightly higher temperature, and in that case, the resin cannot follow the volume change accompanying crystallization and voids are generated.
However, the temperature-transparency change curve shown in FIG. 1 is only a representative example, and by changing the material, the transparency of each state may change depending on the material.
[0021]
A thermoreversible recording medium that reversibly forms a transparent state and an opaque state by a change in heat temperature by the mechanism described above is basically provided with a heat-sensitive layer mainly composed of a resin and a low-molecular-weight organic substance on a support. It is to be configured.
The first problem of the present invention is solved by using a linear hydrocarbon-containing compound (A) selected from the following compounds (1) to (9) having no carboxyl group as the organic low molecular weight substance. The
(1) A linear hydrocarbon-containing compound having a urethane bond.
(2) A linear hydrocarbon-containing compound having a sulfonyl bond.
(3) A linear hydrocarbon-containing compound having an oxalic acid diamide bond.
(4) Linear hydrocarbon-containing compound having a diacyl hydrazide bond
(5) A linear hydrocarbon-containing aliphatic compound having a urea bond and a urethane bond.
(6) A linear hydrocarbon-containing aliphatic compound having a urea bond and an amide bond.
(7) A linear hydrocarbon-containing aliphatic compound having a plurality of urea bonds.
(8) A cyclic compound having a urea bond.
(9) A cyclic compound containing an amide bond.
[0022]
That is, as described above, this linear hydrocarbon-containing compound (A) does not have a carboxyl group, and has a urethane bond (—NHCOO—), a sulfonyl bond (—SOSO) in the molecule.₂It has polar groups such as-), amide bond (-CONH-), oxalic acid diamide bond (-NHCONCONH-), diacyl hydrazide bond (-CONHNHCO-) and urea bond (-HNCONH-).
[0023]
As the linear hydrocarbon-containing compound (A), one or more of the compounds (1) to (9) may be used.
The linear hydrocarbon-containing compound (A) preferably has 6 to 60 carbon atoms in total, and more preferably has 8 to 50 carbon atoms.
Among the linear hydrocarbon-containing compounds (A), (1), (2), (3), (4), (8) and (9) are cyclic hydrocarbons (cyclohexane, cyclopentane, etc.), aromatic Aromatic rings (benzene, naphthalene, etc.), heterocyclic rings (cyclic ether, furan, pyran, morpholine, pyrrolidine, piperidine, pyrrole, pyridine, pyrazine, piperazine, pyrimidine, etc.), condensed heterocyclic rings (benzopyrrolidine, indole, benzoxazine, It preferably contains a cyclic structure such as quinoline. In particular, it preferably has a phenylene structure, a cyclohexylene structure, a phenyl group, a cyclohexyl group, or a heterocyclic ring. Moreover, it is preferable to have a methyl group in at least one of the terminals of the molecule.
[0024]
The melting point of the linear hydrocarbon-containing compound (A) is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, further preferably 120 ° C. or higher, and particularly preferably 130 ° C. or higher.
The melting point is preferably 180 ° C. or lower, more preferably 160 ° C. or lower, and further preferably 150 ° C. or lower.
If the melting point is too low, the clearing temperature range cannot be increased and the erasability is lowered. If the melting point is too high, the sensitivity in forming a cloudy image is lowered, which is not desirable.
[0025]
Examples of the linear hydrocarbon-containing compound (A) include, but are not limited to, those represented by the following general formulas (1) to (6).
R₁-X-R₂-YR_Three                            (1)
[In Formula (1), at least one of X and Y is a urethane bond, a sulfonyl bond, and a urea bond, and the remainder is one selected from a urethane bond, a sulfonyl bond, a urea bond, and an amide bond. R₁, R_ThreeIs CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n− Indicates R₂Is-(CH₂)_m-Or the group represented by the following general formula (i) or (ii) is shown, and m and n are preferably 0-30. ]
[0026]
[Chemical 1]

[Chemical formula 2]

R₁-X-R_Three                                      (2)
[In the formula (2), X represents an oxalic acid diamide bond or a diacyl hydrazide bond;₁, R_ThreeIs CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n-, M and n are preferably 0-30. ]
[0027]
[Chemical 3]

[Formula 4]

[In General Formulas (3) and (4), at least one of X and Y represents a urethane bond, a sulfonyl bond, a urea bond, an amide bond, an oxalic acid diamide bond, or a diacylhydrazide bond. R₁, R₂Is-(CH₂)_m-Or- (CH₂)_m-O- (CH₂)_n− Indicates R_ThreeIs CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n[A] represents a phenyl group, a cyclohexyl group, and groups represented by the following general formulas (iii) to (v), and m and n are preferably 0 to 30. ]
[0028]
[Chemical formula 5]

[Chemical 6]

[Chemical 7]

[In Formula (V), l is 1-3 and Z is R₁OCO-, R₁O-, R₁− Indicates R₁Is CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n-, M and n are preferably 0-30. ]
[0029]
[Chemical 8]

[Chemical 9]

[In the formulas (5) and (6), X represents any one of a urethane bond, a sulfonyl bond, a urea bond, an amide bond, an oxalic acid diamide bond, and a diacyl hydrazide bond. R₁Is-(CH₂)_m-Or- (CH₂)_m-O- (CH₂)_n− Indicates R₂Is CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n-, M and n are preferably 0-30. ]
[0030]
Specific examples of the linear hydrocarbon-containing compound (A) include, for example, those represented by the following general formulas (7) to (22), but are not limited thereto. .
R₁-OOCNH-R₂-NHCOO-R_Three                (7)
R₁-NHCOO-R₂-OOCNH-R_Three                (8)
R₁-SO₂-R₂-SO₂-R_Three                           (9)
R₁-NHCOCONH-R_Three                          (10)
R₁-CONHNHCO-R_Three                          (11)
R₁-NHCO-R₂-NHCONH-R_Three               (12)
R₁-CONH-R₂-NHCONH-R_Three               (13)
R₁-NHCOO-R₂-NHCONH-R_Three             (14)
R₁-NHCONH-R₂-NHCONH-R_Three           (15)
[0031]
[Chemical Formula 10]

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[In the formulas (7) to (22), R₁, R_ThreeIs CH_Three(CH₂)_m-Or CH_Three(CH₂)_m-O- (CH₂)_n−, R₂Is-(CH₂)_m-Or the group represented by the said general formula (i) or (ii) is shown, As for m and n, 0-30 are preferable. )
[0032]
Here, m and n are preferably 1 to 30, more preferably 3 to 26, and still more preferably 5 to 22.
The total number of carbon atoms of the straight chain hydrocarbons in the molecule is preferably 8 or more, more preferably 10 or more, and still more preferably 14 or more.
Moreover, 60 or less are preferable, as for the total carbon number of the linear hydrocarbon in a molecule | numerator, 50 or less are more preferable, and 40 or less are more preferable.
If the number of carbon atoms is too small, compatibility with the resin is improved, and it becomes difficult to form low molecular substance particles, resulting in a problem that the contrast is lowered. This is not desirable because the compatibility of the resin is lowered and the transparent temperature range cannot be expanded.
[0033]
As a compound of the said General formula (7), the following are mentioned, for example.

[0034]
Examples of the compound of the general formula (8) include the following.

Embedded image

[0035]
As a compound of the said General formula (9), the following are mentioned, for example.

[0036]
As a compound of the said General formula (10), the following are mentioned, for example.

[0037]
Examples of the compound of the general formula (11) include the following.

[0038]
As a compound of the said General formula (12), the following are mentioned, for example.

[0039]
Examples of the compound of the general formula (13) include the following.
CH_Three(CH₂)₁₆CONH (CH₂)₆NHCONH (CH₂)₁₇CH_Three   149 ° C
[0040]
As a compound of the said General formula (14), the following are mentioned, for example.
CH_Three(CH₂)₁₇NHCOO (CH₂)₂NHCONH (CH₂)₁₇CH_Three 127 ° C
[0041]
As a compound of the said General formula (15), the following are mentioned, for example.

[0042]
As a compound of the said General formula (16), the following are mentioned, for example.
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[0043]
As a compound of the said General formula (17), the following are mentioned, for example.
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[0044]
As a compound of the said General formula (18), the following are mentioned, for example.
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As a compound of the said General formula (19), the following are mentioned, for example.
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[0045]
As a compound of the said General formula (20), the following are mentioned, for example.
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[0046]
As a compound of the said General formula (21), the following are mentioned, for example.
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[0047]
As a compound of the said General formula (22), the following are mentioned, for example.
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[0048]
An example of a method for synthesizing the linear hydrocarbon-containing compound (A) is shown below.
It is not limited to these.
[Compound represented by the above general formula (7)]
Octadecyloxy-N- [6- (octadecyloxycarbonylamino) hexyl] carboxamide [CH_Three(CH₂)₁₇OOCNH (CH₂)₆NHCOO (CH₂)₁₇CH_Three] Synthesis example.
A tetrahydrofuran solution (125.5 g) of stearyl alcohol (20.1 g) and hexamethylene diisocyanate (5.1 g) was stirred under reflux for 3 hours.
The precipitated crystals were separated by filtration and recrystallized with toluene to obtain 17.7 g of the desired compound.
[0049]
[Compound represented by the above general formula (8)]
1-octadecyl [4- (N-octadecylcarbonyloxy) butoxy] carboxamide [CH_Three(CH₂)₁₇NHCOO (CH₂)_FourOOCNH (CH₂)₁₇CH_Three] Synthesis example.
A tetrahydrofuran solution (103.0 g) of 1,4-butanediol (2.6 g) and stearyl isocyanate (18.0 g) was stirred under reflux for 5 hours.
The precipitated crystals were separated by filtration and recrystallized with toluene to obtain 17.5 g of the target compound.
[0050]
[Compound represented by the above general formula (9)]
1,2-bis (octadecylsulfonyl) ethane [CH_Three(CH₂)₁₇SO₂(CH₂)₂SO₂(CH₂)₁₇CH_Three] Synthesis example.
11.17 g of 1,2-dibromoethane was added dropwise at room temperature to 177.5 g of an ethanol solution containing 35.5 g of stearyl mercaptan and 8.5 g of potassium hydroxide, and the mixture was stirred for 5 hours under reflux. After the stirring, 275 g of 0.8% hydrochloric acid aqueous solution was added at room temperature.
The precipitated crystals were separated by filtration, washed with water and dried to obtain 18.4 g of 1,2-dioctadecylthioethane.
Next, a mixture of 18.4 g of 1,2-dioctadecylthioethane, 184 g of acetic acid and 184 g of hydrogen peroxide (35%) was stirred at 80 to 90 ° C. for 5 hours.
The reaction solution was added to ion-exchanged water at room temperature, and the precipitated crystals were separated by filtration and recrystallized with toluene to obtain 10.6 g of the desired compound.
[0051]
[Compound represented by the above general formula (10)]
N-octadecyl-N-octadecylethane-1,2 diamide
[CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three] Synthesis example.
120.0 g of a tetrahydrofuran solution of 12.0 g of oxalyl chloride was added dropwise to 599.2 g of a tetrahydrofuran solution of 53.5 g of stearylamine and 15.7 g of pyridine at room temperature. After dropping, the mixture was stirred at room temperature for 5 hours.
The precipitated crystals were separated by filtration, washed with water, and recrystallized with toluene to obtain 19.6 g of the desired compound.
[0052]
[Compound represented by the general formula (11)]
N- (Octadecanoylamino) octadecanamide
[CH_Three(CH₂)₁₆CONHNHCO (CH₂)₁₇CH_Three] Synthesis example.
To 205.0 g of a tetrahydrofuran solution of 20.0 g of stearic acid hydrazide, 21.0 g of stearic acid, and 10.3 g of 1-hydroxybenzotriazole, 9.3 g of diisopropylcarbodiimide was added dropwise at room temperature and stirred for 3 hours under reflux. The precipitated crystals were separated by filtration and recrystallized from isopropyl alcohol to obtain 23.9 g of the target compound.
[0053]
[Compound represented by the general formula (12)]
N- (3-Ethoxypropyl) -12- (N'-octadecylureido) dodecanoamide
[CH_ThreeCH₂O (CH₂)_ThreeNHCO (CH₂)₁₁NHCONH (CH₂)₁₇CH_Three ] Synthesis example
A dimethylformamide solution of 30.5 g of octadecyl isocyanate and 21.4 g of 12-aminododecanoic acid was stirred at 60 to 70 ° C. for 8 hours. The precipitated crystals were separated by filtration and recrystallized with toluene. To a solution of 45.2 g of the obtained compound, 12.7 g of ethoxypropylamine and 15.6 g of 1-hydroxybenzotriazole, 17.8 g of diisopropylpropylcarbodiimide was added. The solution was added dropwise at -60 ° C and stirred for 5 hours.
The precipitated crystals were separated by filtration and recrystallized from isopropyl alcohol to obtain 46.1 g of the target compound.
[0054]
[Compound represented by the general formula (17)]
N-benzyl-N'-octadecylurea
Embedded image

A methyl ethyl ketone solution of 14.8 g of octadecyl isocyanate and 6.1 g of benzylamine was stirred under reflux for 6 hours. The precipitated crystals were separated by filtration and recrystallized from isopropyl alcohol to obtain 17.2 g of the objective compound.
[0055]
[Compound represented by the general formula (19)]
6-[(N-octadecylcarbamoyl) amino] -N-phenylhexanoic acid amide
Embedded image

A dimethylformamide solution of 14.1 g of octadecyl isocyanate and 6.2 g of 6-aminocaproic acid was stirred at 50 to 60 ° C. for 5 hours. The precipitated crystals were separated by filtration, recrystallized with toluene, and 5.5 g of diisopropylpropylcarbodiimide was added dropwise to a methyl ethyl ketone solution of 18.7 g of the obtained compound, 5.0 g of aniline and 6.5 g of 1-hydroxybenzotriazole, Stir at reflux for 5 hours.
The precipitated crystals were separated by filtration and recrystallized with ethyl alcohol to obtain 16.3 g of the desired compound.
[0056]
[Compound represented by the general formula (22)]
[3,5-bis (N-octadecylcarbamoyloxy) phenoxy] -N-octadecylcarboxamide
Embedded image

A solution of 4.3 g of benzene-1,3,5-triol and 33.4 g of octadecyl isocyanate in tetrahydrofuran was stirred for 8 hours under reflux. The precipitated crystals were separated by filtration and recrystallized with toluene to obtain 25.6 g of the target compound.
[0057]
The second problem of the present invention is that, in addition to the linear hydrocarbon-containing compound (A) as an organic low-molecular substance, the melting point is 20 ° C. lower than the melting point of the linear hydrocarbon-containing compound (A). This is solved by using a straight-chain hydrocarbon-containing compound (B) having no carboxyl group.
As this linear hydrocarbon containing compound (B), 1 type (s) or 2 or more types can be used.
The linear hydrocarbon-containing compound (B) preferably has a melting point of 50 ° C or higher and lower than 100 ° C. The melting point is more preferably 60 ° C. or higher, further preferably 70 ° C. or higher, and more preferably 90 ° C. or lower.
If the melting point is too low, the heat resistance of the image is lowered, and if it is too high, the transparency temperature range cannot be increased and the erasability is lowered, which is not desirable.
[0058]
The mixing ratio of the linear hydrocarbon-containing compound (A) and the linear hydrocarbon-containing compound (B) is preferably 80:20 to 1:99 by weight.
In this mixing ratio, the ratio of the linear hydrocarbon-containing compound (B) is more preferably 97 or less, further preferably 95 or less, and particularly preferably 90 or less.
Moreover, 30 or more are preferable, 40 or more are more preferable, and 50 or more are further more preferable.
The linear hydrocarbon-containing compounds (A) and (B) may be used singly or in combination of two or more.
If the ratio of the straight-chain hydrocarbon-containing compound (B) is too high, the transparency will be high on the low temperature side and the transparency will be low on the high temperature side, and the transparency will not be uniform. Not desirable.
On the other hand, if the ratio of the linear hydrocarbon-containing compound (B) is too low, sufficient transparency cannot be obtained, which is not desirable.
[0059]
Examples of the linear hydrocarbon-containing compound (B) include fatty acid esters, ketones having higher alkyl groups, dibasic acid esters, polyhydric alcohol difatty acid esters, aliphatic monoamide compounds, and aliphatic monourea compounds. It is not limited to.
[0060]
Specific examples of the linear hydrocarbon-containing compound (B) are listed below.
Examples of fatty acid esters include octadecyl laurate, docosyl laurate, docosyl myristate, dodecyl palmitate, tetradecyl palmitate, pentadecyl palmitate, hexadecyl palmitate, octadecyl palmitate, triaconyl palmitate, octadecyl palmitate, docosyl palmitate , Vinyl stearate, propyl stearate, isopropyl stearate, butyl stearate, amyl stearate, heptyl stearate, octyl stearate, tetradecyl stearate, hexadecyl stearate, heptadecyl stearate, octadecyl stearate, docosyl stearate, stearin Hexacosyl acid, triacontyl stearate, dodecyl behenate, octade behenate Le, docosyl behenic acid, lignoceric acid Torakoshiru include melissic acid myricyl like.
[0061]
Examples of the ketone having a higher alkyl group include 8-pentadecanone, 9-heptadecanone, 10-nonadecanone, 11-heneicosanone, 12-tricosanone, 14-heptacosanone, 16-hentriacontanone, 18-pentatriacontanone, 22 -Tritetracontanone, 2-pentadecanone, 2-hexadecanone, 2-heptadecanone, 2-octadecanone, 2-nonadecanone and the like.
[0062]
As the dibasic acid ester, a diester is preferable, which is represented by the following general formula (23).
ROOC- (CH₂)_n-COOR '(11)
[In Formula (23), R and R ′ represent an alkyl group, and the alkyl group preferably has 1 to 30 carbon atoms, and more preferably 1 to 22 carbon atoms. R and R ′ may be the same or different. n is preferably from 1 to 30, and more preferably from 2 to 20. ]
Specific examples include succinic acid diester, adipic acid diester, sebacic acid diester, 1,18-octadecamethylene dicarboxylic acid ester, and the like.
[0063]
Examples of the polyhydric alcohol difatty acid ester include those represented by the following general formula (24).
CH_Three(CH₂)_{m − 2}COO (CH₂)_nOOC (CH₂)_{m − 2}CH_Three  (24)
(Formula (24), n is 2-40, preferably 3-30, more preferably 4-22. M is 2-40, preferably 3-30, more preferably 4-22.)
Specific examples include 1,3-propanediol dialkanoic acid ester, 1,6-hexanediol dialkanoic acid ester, 1,10 decanediol dialkanoic acid ester, 1,18 octadecanediol dialkanoic acid ester, and the like.
[0064]
Examples of the fatty acid monoamide include those represented by the following general formula (25).
R-CONH-R (25)
(In formula (25), R represents a linear hydrocarbon chain having 1 to 25 carbon atoms, R represents a linear hydrocarbon chain having 1 to 26 carbon atoms, a methylol group or hydrogen, and at least one of R and R) One is a straight hydrocarbon chain having 10 or more carbon atoms.)
Specifically, N-lauryl lauric acid amide, N-palmityl palmitic acid amide, N-stearyl palmitic acid amide, N-behenyl palmitic acid amide, N-palmityl stearic acid amide, N-stearyl stearic acid amide, N -Behenyl stearic acid amide, N-palmityl behenic acid amide, N-stearyl behenic acid amide, N-behenyl behenic acid amide etc. can be mentioned.
[0065]
Examples of the aliphatic urea compound include those represented by the following general formula (26).
R-NHCONH-R (26)
[In Formula (26), R and R represent an alkyl group, an alicyclic group, or an aromatic group, and at least one of them is a straight chain hydrocarbon chain having 1 to 26 carbon atoms. )
Specifically, N-butyl-N-stearyl urea, N-phenyl-N-stearyl urea, N-stearyl-N-stearyl urea, N-behenyl-N-stearyl urea, N-stearyl-N-behenyl urea, N-behenyl-N-behenylurea etc. are mentioned.
[0066]
The thermoreversible recording medium of the present invention preferably has the following (i) to (iii) as conditions under which the transparent state and the opaque state reversibly change depending on the temperature.
(I) The transparent upper limit temperature is 115 ° C. or higher.
(Ii) The temperature difference between the transparency upper limit temperature and the opacification lower limit temperature is 20 ° C. or less.
(Iii) The transparent temperature range is 30 ° C. or higher.
[0067]
Clearance upper limit temperature (TWX), Opacification (white turbidity) lower limit temperature (TVO), Temperature difference between transparency upper limit temperature and opacity lower limit temperature (ΔTWV), Clearance start temperature (TWD), Clearance temperature range (ΔTZ) ) Is determined as follows. First, a white turbid thermoreversible recording medium is prepared.
In order to use a transparent medium or a medium that is not sufficiently clouded, the medium is clouded in advance by pressing the medium against a sufficiently heated hot plate and heating. The heating time may be about 10 to 30 seconds.
In order to confirm that the heating temperature is sufficient to cause white turbidity, the heating may be performed again at a slightly higher temperature (for example, a temperature higher by 10 ° C.).
If the turbidity does not change between the two, the initial heating temperature is sufficiently high to cause turbidity.
If the white turbidity is higher when heated at a slightly higher temperature, the temperature is still lower at the first temperature, and the heating temperature is raised and the same can be repeated.
[0068]
Next, the white turbid recording medium is heated while changing the temperature, and the temperature at which it becomes transparent is examined. A thermal tilt tester (HG-100 manufactured by Toyo Seiki Co., Ltd.) is used for heating the recording medium.
This thermal gradient tester has 5 heating blocks, each block can set the temperature individually, it is also possible to control the heating time and pressure, and at the set conditions, at 5 different temperatures at a time The medium can be heated.
Specifically, the heating time is 1 second, the heating pressure is about 2.5 kg / cm, and the heating temperature is from 1 to 5 ° C. at a constant temperature interval from a low temperature at which white does not change even when heated. Heat to a temperature that is sufficiently cloudy.
In order to prevent the medium from sticking to the heat block, a thin film of polyimide or polyamide (10 μm or less) may be placed on top.
After heating in this way, cooling to room temperature, using a Macbeth RD-914 reflection densitometer, measuring the density of the heated part at each temperature, the horizontal axis is the set temperature of the thermal tilt tester as shown in FIG. Create a graph with the vertical axis as the reflection density.
[0069]
FIG. 2 is a graph showing the relationship between the set temperature and the reflection density of this thermal inclination tester.
When the thermoreversible recording medium uses a transparent support, a sheet that absorbs light or a sheet that regularly reflects light deposited with a metal such as Al is laid on the back of the medium and the density is measured. .
The graph is completed by plotting the concentration values for each temperature and then connecting the plotted adjacent points with a straight line. The created graph usually has a trapezoidal shape as shown in FIG.
[0070]
These data are affected by the thickness and material of the medium including the heat-sensitive layer and the support.
If the thickness of the medium is 300 μm or less, it is not affected by the thickness and almost the same data can be obtained. However, if the thickness is more than that, the thickness of the medium is reduced to 300 μm or less by scraping or peeling the support side. Or what is necessary is just to convert the thick part.
Any material may be used as long as the material is a polymer, but in the case of metal or the like, conversion is necessary.
From this graph, the above clearing upper limit temperature and whitening lower limit temperature are read and calculated.
First, the maximum density value (DPD) is read in this graph. Next, a line of y = 0.7 × DPD [is drawn, and a plot point having a higher concentration than this line is selected.
The number of plot points is preferably 5 to 20 points.
If the number of plot points is small, the subsequent calculation results are uncertain.
When the number of plot points is small, it is necessary to narrow the heating temperature interval in the above-described thermal gradient tester and increase the number.
Among the selected plot points, the same number of those having a high density value and the one having a low density value are excluded, and the average density of the remaining density values is defined as an average transparent density (DWDY).
The ratio of excluding large and small density values is 10 to 30%, preferably 15 to 25%, of the selected plot points.
By excluding those having a large density value and those having a small density value, an accurate value of the transparent density of the medium can be calculated.
[0071]
Next, the lower transparency limit concentration (DWP) is calculated by the following mathematical formula (1).
DWP = DWDY−0.2 × (DWDY−DPLQ) (1)
Here, DPLQ is the maximum cloudy concentration, and when the temperature is raised and the adjacent three plotted points are within a concentration value of 0.3, it is calculated from the average value of the three points. DWP represents a density that is visually transparent when it is above this density.
Further, a line y = DWP is drawn on the graph to obtain the temperature at the intersection with the concentration temperature curve. Of these intersections, the low temperature side is defined as a lower transparency limit temperature (TWO), and the high temperature side is defined as a transparent upper limit temperature (TWX). The transparency temperature range (ΔTZ) is obtained by the following mathematical formula (2).
ΔTw = TWX-TWO (2)
[0072]
Further, the white turbidity upper limit concentration (Ds) is calculated by the following mathematical formula (3).
Ds = DPLQ + 0.1 × (DWDY−DPLQ) (3)
A line y = Ds is drawn on the graph, and the temperature at the intersection with the portion where the concentration-temperature curve changes from transparent to cloudy is defined as the clouding lower limit temperature (TVO).
The difference (ΔTWV) between the clearing upper limit temperature and the clouding lower limit temperature is obtained by the following formula (4).
ΔTWV = TVO-TWX (4)
The clearing start concentration (DWD) is obtained by the following mathematical formula (5).
DWD = DPLQ + 0.25 × (DWDY−DPLQ) (5)
The transparency start temperature (TWD) is obtained from the intersection of y = DWV and the graph as shown in FIG.
[0073]
The transparency upper limit temperature (TWX) is preferably 115 ° C. or higher.
By increasing the temperature of TWX, it is possible to expand the transparent temperature range without degrading the image durability.
The maximum transparency temperature (TWX) is preferably 120 ° C. or higher, more preferably 125 ° C. or higher, and further preferably 130 ° C. or higher.
As this temperature increases, the print sensitivity improves.
Further, TWX is preferably 170 ° C. or lower, more preferably 160 ° C. or lower, and further preferably 150 ° C. or lower.
The lower the temperature, the higher the printing sensitivity.
It is preferable that the difference (ΔTWV) between the clearing upper limit temperature and the clouding lower limit temperature is 20 ° C. or less.
If the TWV is larger than this, the temperature at which the cloudiness becomes higher than necessary is necessary, so when forming a cloudy image, very high energy is required. This is not desirable because the turbidity of the image is reduced.
ΔTWV is preferably 15 ° C. or lower, and more preferably 10 ° C. or lower.
[0074]
The transparency start temperature (TWD) is preferably less than 95 ° C, more preferably 90 ° C or less, and further preferably 85 ° C or less.
The TWD is preferably 70 ° C. or higher, and more preferably 75 ° C. or higher.
When this temperature is low, the erasability is improved, and when it is high, the image heat resistance is improved.
The clearing temperature range (ΔTZ) is preferably 30 ° C. or more.
When ΔTZ is smaller than this, erasability is lowered.
The transparency temperature range (ΔTZ) is more preferably 40 ° C. or higher, further preferably 45 ° C. or higher, and particularly preferably 50 ° C. or higher.
A wider temperature range improves erasability.
Further, ΔTZ is preferably 100 ° C. or less, more preferably 90 ° C. or less, and further preferably 80 ° C. or less.
In particular, when the clearing temperature range (ΔTZ) is wider, there is an advantage that uniform erasure is possible even if the processing speed at the time of erasure is increased.
In this case, ΔTZ is preferably 60 ° C. or higher, and more preferably 70 ° C. or higher. In particular, when the clearing temperature range (ΔTZ) is wider, there is an advantage that uniform erasure is possible even if the processing speed at the time of erasure is increased.
In this case, ΔTZ is preferably 60 ° C. or higher, and more preferably 70 ° C. or higher.
[0075]
Although it does not specifically limit as a support body, The metal vapor deposition film etc. which vapor-deposited metals, such as aluminum, on these things, such as a film-like thing or plate-like thing consisting of synthetic resins, such as polyester, polyvinyl chloride, and polyimide, etc. are mentioned. It is done.
Resin as a base material used for the heat-sensitive layer is a material that forms a layer in which an organic low molecular weight substance is uniformly dispersed and held, and affects the transparency at the time of maximum transparency.
For this reason, the resin base material is preferably a resin having good transparency, mechanical stability and good film formability.
This resin preferably has a glass transition temperature of 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher.
Further, the glass transition temperature is preferably less than 100 ° C, more preferably less than 90 ° C.
If the glass transition temperature is too low, the heat resistance of the image is lowered, and if it is too high, the erasability is lowered.
[0076]
This resin preferably has a gel fraction of 30% or more, more preferably 50% or more, still more preferably 70% or more, and particularly preferably 80% or more.
Here, the gel fraction refers to the ratio of gel formation when a resin solute in a solvent loses its independent mobility due to interaction and assembles into an individualized state (gel).
When the gel fraction is small, repeated durability is lowered. Therefore, in order to improve the gel fraction, a curable resin that is cured by heat, UV, EB, or the like may be mixed in the resin, or the resin itself may be crosslinked.
[0077]
As a gel fraction measurement method, the membrane is peeled off from the support and the initial weight of the membrane is measured, and then the membrane is placed in a 400 mesh wire net and immersed in a solvent in which the resin before crosslinking is soluble for 24 hours. Then vacuum dry and measure the weight after drying.
The gel fraction calculation is performed according to the following formula.
Gel fraction (%) = [weight after drying (g) / initial weight (g)] × 100
When calculating the gel fraction by this calculation, the calculation is performed excluding the weight of organic low-molecular substance particles other than the resin component in the heat-sensitive layer.
At this time, when the weight of the organic low molecular weight substance is not known in advance, the weight ratio is obtained from the area ratio per unit area and the specific gravity of the resin and the low molecular weight organic substance by cross-sectional observation such as TEM and SEM. The gel fraction value may be calculated by calculating the molecular substance weight.
[0078]
In the case of the above measurement, a reversible thermosensitive layer is provided on the support and another layer such as a protective layer is laminated thereon, or other layers are provided between the support and the thermosensitive layer. If there is a layer, as described above, first check the film thickness of the reversible thermosensitive layer and other layers by observing the cross section of the TEM, SEM, etc. In addition to exposing the surface of the reversible heat-sensitive layer, the reversible heat-sensitive layer may be peeled off and gel fraction measurement may be performed in the same manner as in the measurement method.
In addition, in this method, when there is a protective layer made of an ultraviolet curable resin or the like in the upper layer of the heat sensitive layer, in order to prevent this layer from mixing as much as possible, the thickness of the protective layer is reduced and the surface of the heat sensitive layer is slightly It is necessary to prevent the influence on the shaving gel fraction value.
[0079]
This resin is preferably cross-linked, and when it is cross-linked, the thermal recording medium is less susceptible to changes in the internal structure of the heat-sensitive layer even after repeated printing and erasing, and has improved repeated durability, such as no decrease in turbidity and transparency. To do.
In the case of crosslinking, the resin preferably has a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an acryloyl group, or a methacryloyl group.
Examples of the crosslinking method include thermal crosslinking, UV and EB irradiation methods, and it is preferable to perform crosslinking by adding a crosslinking agent such as an isocyanate compound, a functional acrylic monomer, or a methacrylic monomer.
[0080]
Such resins include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer. Polymers such as vinyl chloride copolymers; polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymers, vinylidene chloride copolymers such as vinylidene chloride-acrylonitrile copolymers; polyesters; polyamides; polyacrylates or polymethacrylates or acrylates -Methacrylate copolymer; silicone resin and the like.
These resins may be used alone or in combination of two or more.
[0081]
In the case of a combination of a thermoplastic resin having a hydroxyl group and an isocyanate compound, the isocyanate compound is preferably used by mixing a chain isocyanate compound and a cyclic isocyanate compound.
When only the chain isocyanate compound is used, the crosslinked resin is usually soft and the erasability is improved. However, if the heat-sensitive layer is too soft, there is a disadvantage that the repeated durability and the image heat resistance are lowered.
On the contrary, when only the cyclic isocyanate compound is used, the cross-linked resin becomes rigid and repeatability and image heat resistance are improved, but there is a drawback that erasability is lowered.
By mixing and using a chain isocyanate compound and a cyclic isocyanate compound, it becomes possible to achieve both erasability, durability and heat resistance.
The mixing ratio of the chain isocyanate compound and the cyclic isocyanate compound is preferably 90:10 to 10:90, more preferably 90:10 to 30:70, and more preferably 80:20 to 30:70. preferable.
As the amount of the chain isocyanate compound is increased, the erasure rate and the maximum erasure inclination are improved, and as a result, the contrast can be improved.
[0082]
Examples of the chain isocyanate compound include those obtained by reacting a chain compound having a hydroxyl group such as triol and an aliphatic isocyanate such as hexamethylene diisocyanate directly or via one or more ethylene oxides or propylene oxides. It is done.
The molecular weight of the chain isocyanate compound is preferably 500 or more, more preferably 700 or more, and even more preferably 1000 or more.
Moreover, 5000 or less are preferable, 4000 or less are more preferable, and 3000 or less are more preferable.
If the molecular weight is too small, the cross-linked coating film is less likely to have a flexible structure, so the erasability is lowered. If the molecular weight is too large, the molecule is difficult to move, and the degree of crosslinking is lowered and durability is lowered.
[0083]
The molecular weight per isocyanate group is preferably 250 or more, more preferably 300 or more, and still more preferably 400 or more.
Moreover, 2000 or less is preferable, 1500 or less is more preferable, and 1000 or less is further more preferable.
If the molecular weight per isocyanate group is too small, the cross-linked coating film will not easily have a flexible structure, so the erasability will be reduced. If the molecular weight is too large, the molecule will be difficult to move and the degree of crosslinking will be reduced and durability will be reduced Sex is reduced.
[0084]
The cyclic isocyanate compound is an isocyanate compound having a benzene ring or an isocyanurate ring.
Among these, the type having an isocyanurate ring is preferably used because it does not yellow.
The cyclic isocyanate compound preferably has a chain structure such as an alkylene chain in addition to the cyclic structure.
The molecular weight of the cyclic isocyanate compound is preferably 100 or more, more preferably 200 or more, and still more preferably 300 or more. Moreover, less than 1000 is preferable and less than 700 is more preferable.
If the molecular weight is too small, it evaporates by heating at the time of coating film formation and the coating film cannot be cross-linked and the durability is lowered. If the molecular weight is too large, a rigid structure cannot be formed and the durability is lowered. As the mixture of the chain isocyanate compound and the cyclic isocyanate compound, the above materials may be mixed and used, or a mixed product may be used.
Examples of the product of the mixture include “Coronate 2298-90T” manufactured by Nippon Polyurethane Co., Ltd., but are not limited thereto.
[0085]
The thickness of the thermosensitive layer of the thermoreversible recording medium of the present invention is preferably 1 to 30 μm, more preferably 2 to 20 μm, and even more preferably 4 to 15 μm. If the recording layer is too thick, heat distribution occurs in the layer, making it difficult to make the recording layer uniform transparent. On the other hand, if the heat sensitive layer is too thin, the white turbidity is lowered and the contrast is lowered.
The white turbidity can be increased by increasing the amount of fatty acid in the recording layer and crosslinking the resin in the heat sensitive layer.
[0086]
The ratio of the organic low molecular weight substance and the resin in the heat-sensitive layer is preferably about 2: 1 to 1:16 by weight, more preferably 1: 2 to 1: 8, and particularly preferably 1: 2 to 1: 5. 1: 2 to 1: 4 are more particularly preferable.
1: 2.5 to 1: 4 is the most preferred ratio.
If the ratio of the resin is less than the above, it becomes difficult to form a film in which the organic low molecular weight substance is held in the resin. .
[0087]
In the present invention, a protective layer can be provided on the heat sensitive layer to protect the heat sensitive layer.
The thickness of the protective layer is suitably 0.1 to 5 μm. Examples of the material include silicone rubber or silicone resin as disclosed in JP-A-63-221087, JP-A-63. Examples thereof include polysiloxane graft polymers as described in JP-A No. 317385 / ultraviolet curable resins and electron beam curable resins as described in JP-A No. 02-566.
Furthermore, an organic or inorganic filler can be contained in the protective layer.
[0088]
Further, in order to protect the heat-sensitive layer from the solvent, monomer component, etc. of the protective layer-forming liquid, an intermediate layer can be provided between the protective layer and the heat-sensitive layer as described in JP-A No. 1-133781. .
Examples of the material for the intermediate layer include resins used for the heat-sensitive layer, but thermosetting resins, thermoplastic resins, UV curable resins, and EB curable resins can also be used. Examples of such materials include polyethylene, polypropylene, polystyrene, polyvinyl alcohol, polyvinyl butyral, polyurethane, saturated polyester, unsaturated polyester, epoxy resin, phenol resin, polycarbonate, and polyamide. The thickness of the intermediate layer is preferably about 0.1 to 2 μm. If the thickness is 0.1 μm or more, the effect of the protective layer can be maintained, and if it is 2 μm or less, the thermal sensitivity does not decrease.
[0089]
Furthermore, a layer that regularly reflects light may be provided between the support and the heat-sensitive layer to improve the contrast. This light reflecting layer is usually formed by a method such as vapor deposition of a metal such as aluminum, and the thickness is preferably about 100 to 1000 mm.
[0090]
In the thermoreversible recording label of the present invention, an adhesive layer or a pressure-sensitive adhesive layer is provided on the surface opposite to the surface on which the heat-sensitive layer of the support constituting the thermoreversible recording medium is formed.
This thermoreversible recording label includes an adhesive layer or a pressure-sensitive adhesive layer (non-peeling paper type) and a label with a release paper under the adhesive layer or pressure-sensitive adhesive layer (release paper type). In addition, as a material constituting the adhesive layer, a hot-melt type is usually used.
[0091]
Commonly used materials can be used for the adhesive layer or the pressure-sensitive adhesive layer. For example, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin, vinyl acetate-acrylic copolymer, ethylene-vinyl acetate copolymer, acrylic resin, polyvinyl ether resin, vinyl chloride-vinyl acetate Copolymer, polystyrene resin, polyester resin, polyurethane resin, polyamide resin, chlorinated polyolefin resin, polyvinyl butyral resin, acrylic ester copolymer, methacrylic ester copolymer, natural rubber , Cyanoacrylate resins, silicon resins, and the like, but are not limited thereto.
[0092]
Next, a member having an information storage unit and a reversible display unit and using at least the thermosensitive layer constituting the above-described thermoreversible recording medium as the reversible display unit will be described.
Specific examples of the member having the information storage unit and the reversible display unit include the following.
(1) A heat-sensitive layer is directly formed using a part of a member having an information recording part as a support for a thermoreversible recording medium.
(2) A member having an information recording part, wherein the support surface of the thermoreversible recording medium is bonded.
(3) The thermoreversible recording label is bonded to a member having an information recording portion via an adhesive layer or an adhesive layer.
(4) An information recording unit provided on the thermoreversible recording medium.
(In the case of (4), it is preferable to use a thick support as the support constituting the thermoreversible recording medium)
[0093]
In any of the cases (1) to (4), it is necessary to set the information storage unit and the reversible display unit so that the respective functions can be exhibited. Is not limited, for example, it may be provided on the surface of the support opposite to the surface on which the heat-sensitive layer is provided, or between the support and the heat-sensitive layer, or on a part of the heat-sensitive layer. You can also.
[0094]
The member used as the member having the information recording unit is not particularly limited, but generally includes a card, a disk, a disk cartridge, or a tape cassette. Examples of these include the following.
Thick cards such as IC cards or optical cards, floppy disks, magneto-optical recording disks (MD), disk cartridges with built-in disks that can rewrite storage information such as DVD-RAM, disks that do not use disk cartridges such as CD-RW A member having both the reversible display unit and the information storage unit, such as a write-once disc such as a CD-R, a video tape cassette, etc., for example, in the case of a card, a part of the information stored in the information storage unit By displaying on the heat-sensitive layer, cardholders can check the information just by looking at the card without any special device, which is more convenient than a card that does not apply a thermoreversible recording medium. Will be greatly improved.
[0095]
The information storage unit is not particularly limited as long as it can store necessary information. For example, magnetic recording, contact IC, non-contact IC, or optical memory is useful.
The magnetic recording layer is formed by coating the support using a commonly used metal compound such as iron oxide or barium ferrite and a resin such as vinyl chloride, urethane or nylon, or without using a resin. It forms by methods, such as vapor deposition and sputtering, using the said metal compound.
In addition, a thermoreversible recording medium used for display is a thermosensitive layer such as a barcode, a two-dimensional code,
It can also be used as a storage unit in a manner.
[0096]
As an example of using the thermoreversible recording label of (3) above, in the case of a thick material that is difficult to apply a heat-sensitive layer as a support, such as a vinyl chloride card with a magnetic stripe, it is adhered to the entire surface or a part thereof. An agent layer or an adhesive layer can be provided. By doing so, the convenience of this medium can be improved, such as being able to display part of the information stored in the magnetism.
The thermoreversible recording label provided with this adhesive layer or pressure-sensitive adhesive layer can be applied not only to the above-mentioned magnetic PVC card but also to a thick card such as an IC card or an optical card.
[0097]
Further, this thermoreversible recording label can be used in place of a display label on a disk cartridge having a built-in rewritable disk such as a floppy disk, MD or DVD-RAM.
FIG. 3 shows an example in which a thermoreversible recording label is pasted on an MD disk cartridge.
Furthermore, in the case of a disc that does not use a disc cartridge such as a CD-RW, a thermoreversible recording label can be directly attached to the disc, or a heat-sensitive layer can be provided directly on the disc.
In this way, the present invention can be applied to uses such as automatically changing display contents in accordance with changes in the stored contents.
FIG. 4 shows an example in which a thermoreversible recording label is pasted on a CD-RW.
[0098]
The thermoreversible recording label of the present invention can also be used to rewrite and display a part of the stored information added to the CD-R by attaching the thermoreversible recording label on a write-once disc such as a CD-R.
FIG. 5 shows an example of a configuration in which a thermoreversible recording label is formed on an optical information recording medium (CD-RW) using an AgInSbTe phase change type storage material. The basic configuration is that a first dielectric layer, an optical information storage layer, a second dielectric layer, a reflective heat dissipation layer, and an intermediate layer are provided on a substrate having guide grooves, and a hard coat layer is provided on the back surface of the substrate. Further, a thermoreversible recording label is affixed on the intermediate layer.
The dielectric layer is not necessarily provided on both sides of the recording layer, but it is desirable to provide the first dielectric layer when the substrate is a material having low heat resistance such as polycarbonate resin.
[0099]
Further, as shown in FIG. 6, it may be used as a display label of a video tape cassette.
As a method for providing a thermoreversible recording function on a thick card, a disk cartridge, and a disk, in addition to the above-described method of applying a thermoreversible recording label, a method of directly applying a heat-sensitive layer on them, There is a method of forming a heat sensitive layer on a thick card, a disc cartridge, a method of transferring the heat sensitive layer onto a disc, and the like.
When transferring, an adhesive layer such as a hot-melt type or an adhesive layer may be provided on the heat-sensitive layer.
When sticking a thermoreversible recording label on a rigid card such as a thick card, disk, disk cartridge, or tape cassette, or when providing a heat-sensitive layer, the contact with the thermal head is improved and the image is uniform. It is preferable to provide a layer or sheet that is elastic and cushions between the rigid substrate and the label or heat-sensitive layer.
[0100]
For example, as shown in FIG. 7a, the reversible thermosensitive recording medium of the present invention is a film in which a reversible thermosensitive recording layer (13) and a protective layer (14) are provided on a support (11). As shown in FIG. 7c, a film comprising an aluminum reflective layer (12), a reversible thermosensitive recording layer (13) and a protective layer (14) on a support (11), as shown in FIG. 7c. A film in which an aluminum reflective layer (12), a reversible thermosensitive recording layer (13) and a protective layer (14) are provided on the body (11), and a magnetic recording layer (16) is provided on the back surface of the support (11); As shown in FIG. 8, the card can be processed into a card (21) having a print display section (23).
[0101]
Further, for example, as shown in FIG. 9a, a film in which an aluminum reflective layer (12), a reversible thermosensitive recording layer (13), and a protective layer (14) are provided on a support (11) in a card shape. It can be made into the form processed and formed into the card shape while forming the hollow part (23) which accommodates an IC chip.
In this example, a rewrite recording part (24) is labeled on a card-like reversible thermosensitive recording medium, and a recess (23) for embedding an IC chip is provided at a predetermined position on the back side of the reversible thermosensitive recording medium. In this recess (23), a wafer (231) as shown in FIG. 9b is incorporated and fixed.
In the wafer (231), an integrated circuit (233) is provided on the wafer substrate (232), and a plurality of contact terminals (234) electrically connected to the integrated circuit (233) include a wafer substrate (232). Is provided.
The contact terminal (234) is exposed on the back side of the wafer substrate (232), and a dedicated printer (reader / writer) electrically contacts the contact terminal (234) to read or rewrite predetermined information. It is configured to be able to.
[0102]
An example of the function of this reversible thermosensitive recording card will be described with reference to FIG.
FIG. 10A is a schematic configuration block diagram showing the integrated circuit 233, and FIG. 10B is a configuration block diagram showing an example of data stored in the RAM.
The integrated circuit (233) is composed of, for example, an LSI, in which a CPU (235) that can execute a control operation in a predetermined procedure, and a ROM that stores operation program data of the CPU (235) (236) and a RAM (237) capable of writing and reading necessary data.
Further, the integrated circuit (233) receives an input signal, gives input data to the CPU (235), receives an output signal from the CPU (235), and outputs it to the outside, and an input / output interface (238) not shown. Includes a power-on reset circuit, a clock generation circuit, a pulse frequency division circuit (interrupt pulse generation circuit), and an address decoder circuit.
[0103]
The CPU (235) can execute the operation of the interrupt control routine according to the interrupt pulse periodically given from the pulse frequency dividing circuit.
The address decoding circuit decodes address data from the CPU (235) and supplies signals to the ROM (236), RAM (237), and input / output interface (238).
A plurality (eight in the figure) of contact terminals (234) are connected to the input / output interface (238), and predetermined data from the dedicated printer (reader / writer) is input from the contact terminals (234). The data is input to the CPU (235) via the output interface (238). The CPU (235) performs each operation in response to the input signal and according to the program data stored in the ROM (236), and sends predetermined data and signals to the card via the input / output interface (238). This is output to the reader / writer.
[0104]
As shown in FIG. 10B, the RAM (237) includes a plurality of storage areas (239a) to (239f).
For example, a card number is stored in the area (239a), ID data such as a cardholder's name, address, and telephone number is stored in (239b), for example, and the owner's name is stored in the area (239c). Information corresponding to the remaining valuable value or valuable material that can be used is stored, and information corresponding to the used valuable value or valuable material is stored in the areas (239d), (239e), (239f), and (239g).
[0105]
The present invention further provides an image processing method and the thermoreversible recording medium, wherein the thermoreversible recording medium, the member having the information storage unit or the label is used to form and / or erase an image by heating. An image processing apparatus having a member having the information storage unit or the label and forming and / or erasing an image by heating is provided.
[0106]
For image formation, an image recording means such as a thermal head, a laser or the like that can partially heat the medium on the image is used.
For image erasing, an image erasing means such as a hot stamp, a ceramic heater, a heat roller, hot air, a thermal head, or a laser is used.
Among these, a ceramic heater is preferably used. By using a ceramic heater, the apparatus can be miniaturized, a stable erased state can be obtained, and an image with good contrast can be obtained.
The set temperature of the ceramic heater is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, and even more preferably 115 ° C. or higher.
Further, by using a thermal head as the image erasing means, the entire apparatus can be further downsized.
[0107]
Furthermore, power consumption can be reduced, and a battery-operated handy type device is also possible.
If a single thermal head is used for both forming and erasing, the size can be further reduced.
When forming and erasing with a single thermal head, once the previous image has been erased, a new image may be formed again. The energy is changed for each image, and the previous image is erased at one time. It is also possible to use an overwrite method that forms the film.
In the overwrite method, the time required for forming and erasing is reduced, and the recording speed is increased.
In the case of using a card having a heat-sensitive layer and an information storage unit, the above-described device includes means for reading and rewriting the memory of the information storage unit.
[0108]
FIG. 11 shows an example of the image processing apparatus of the present invention. FIG. 11 shows a schematic example of an apparatus for erasing an image with a ceramic heater and forming an image with a thermal head according to the present invention.
In the image processing apparatus of FIG. 11, first, information stored in the magnetic recording layer of the recording medium is read with a magnetic head, and then the image recorded on the reversible thermosensitive layer is heated and erased with a ceramic heater, Based on the information read by the magnetic head, new processed information is recorded on the reverse heat-sensitive layer by the thermal head.
Thereafter, the information on the magnetic recording layer is also rewritten with new information.
[0109]
That is, in the image processing apparatus of FIG. 11, the thermoreversible recording medium (1) provided with the magnetic recording layer on the opposite side of the thermosensitive layer is transported along the transport path shown by the reciprocating arrow, or transported. It is conveyed in the reverse direction in the apparatus along the path.
The thermoreversible recording medium (1) is magnetically recorded or erased on the magnetic recording layer between the magnetic head (34) and the conveying roller (31), and the image is erased between the ceramic heater (38) and the conveying roller (40). Therefore, heat treatment is performed, and an image is formed between the thermal head (53) and the conveyance roller (47), and thereafter, it is carried out of the apparatus.
However, the rewriting of the magnetic recording may be performed before or after the image erasure by the Mic heater.
If desired, after passing between the ceramic heater (38) and the transport roller (40), or after passing between the thermal head (53) and the transport roller (47), the transport path is transported in the opposite direction, and the ceramic heater ( 38) The second heat treatment and the second printing process by the thermal head (53) can be performed.
[0110]
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited at all by these Examples.
[0111]
Example 1
On the PET film side of Dainippon Ink & Co., Ltd. magnetic original (memory dick, DS-1711-1040: 188 μm thick transparent PET film coated with magnetic recording layer and self-cleaning layer), about 400 mm A light reflecting layer was provided by vacuum deposition of Al.
in addition,
10 parts of vinyl chloride-vinyl acetate-phosphate ester copolymer
(Denka Vinyl # 1000P, manufactured by Denki Kagaku Kogyo Co., Ltd.)
45 parts of methyl ethyl ketone
45 parts of toluene
A solution consisting of the above was applied and dried by heating to provide an adhesive layer having a thickness of about 0.5 μm.
Next, in a resin solution in which 26 parts of vinyl chloride copolymer (manufactured by Zeon Corporation, MR110) was dissolved in 230 parts of methyl ethyl ketone,
Behenyl behenate (Prototype of Miyoshi Oil & Fats Co., Ltd.) 6 parts
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three
(Miyoshi Oil & Fats Prototype) 4 copies
Was added, and ceramic beads having a diameter of 2 mm were put in a glass bottle and dispersed for 48 hours using a paint shaker (manufactured by Asada Tekko Co., Ltd.) to prepare a uniform dispersion.
To this dispersion liquid, 4 parts of an isocyanate compound (manufactured by Nippon Polyurethane Co., Coronate 2298-90T) was added to prepare a heat-sensitive layer liquid, which was applied onto the adhesive layer of the PET film having the magnetic recording layer, dried by heating, Furthermore, it preserve | saved for 72 hours in 60 degreeC environment, resin was bridge | crosslinked, and the thermosensitive layer about 10 micrometers thick was provided.
[0112]
On this heat sensitive layer,
Urethane acrylate UV curable resin 75% butyl acetate solution
(Dainippon Ink & Chemicals, Unidic C7-157) 10 parts
10 parts isopropyl alcohol
A solution consisting of the above was applied with a wire bar, heated and dried, then irradiated with an ultraviolet ray with an 80 w / cm high-pressure mercury lamp and cured, and a protective layer having a thickness of about 3 μm was provided to prepare a thermoreversible recording medium.
[0113]
Example 2
8 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 2 parts was used.
[0114]
Example 3
9 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 1 part was used.
[0115]
Example 4
9.5 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that the content was changed to 0.5 part.
[0116]
Example 5
A thermoreversible recording medium was produced in the same manner as in Example 2 except that behenyl behenate was replaced with diheptadecyl ketone (manufactured by Nippon Kasei Chemical Co., Ltd., wax KS).
[0117]
Example 6
A thermoreversible recording medium was produced in the same manner as in Example 2 except that behenyl behenate was replaced with ethanolamine distearate (Nihon Kasei Co., Ltd., Sladeid S).
[0118]
Example 7
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three, CH_Three(CH₂)₁₆CONHNHCO (CH₂)₁₆CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 4 except that (Miyoshi Oil & Fats Prototype) was used.
[0119]
Example 8
A thermoreversible recording medium was produced in the same manner as in Example 7 except that behenyl behenate was replaced with diheptadecyl ketone (manufactured by Nippon Kasei Co., Ltd., wax KS).
[0120]
Example 9
A thermoreversible recording medium was produced in the same manner as in Example 7 except that behenyl behenate was replaced with ethanolamine distearate (Nihon Kasei Co., Ltd., Sladeid S).
[0121]
Example 10
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three, CH_Three(CH₂)₁₇OOCNH (CH₂)₆NHCOO (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 4 except that (Miyoshi Oil & Fats Prototype) was used.
[0122]
Example 11
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three, CH_Three(CH₂)₁₇NHCOO (CH₂)_FourOOCNH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 2 except that (Miyoshi Oil & Fats Prototype) was used.
[0123]
Example 12
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_Three, CH_Three(CH₂)₁₇SO₂(CH₂)₂SO₂(CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 4 except that (Miyoshi Oil & Fats Prototype) was used.
[0124]
Example 13
CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 2 except that the following material (Miyoshi Yushi Co., Ltd. prototype) was used.
Embedded image

[0125]
Example 14
An adhesive layer, a heat-sensitive layer, and a protective layer were formed in the same manner as in Example 1 on the Al-deposited surface of an Al-deposited polyester film (# 50 Metal Me, manufactured by Toray Industries, Inc.) having a thickness of about 50 μm.
Further, an approximately 5 μm acrylic pressure-sensitive adhesive layer was provided on the back surface of the heat-sensitive layer surface of the support to produce a thermoreversible recording label.
This label was formed into a donut shape as shown in FIG. 4 and pasted onto a CD-RW as shown in FIG. 5 to produce an optical information recording medium with a reversible display function.
[0126]
Using the optical information recording medium produced as described above, a part of the information (date, time, etc.) stored in the CD-RW drive [manufactured by Ricoh Co., Ltd., MP6200S] is recorded as recording means (thermal head). Using a recording apparatus having an erasing means (ceramic heater), the recording energy of the thermal head was adjusted in accordance with the change in the recording temperature of each medium, displayed and recorded on the heat sensitive layer, and visualized.
Also, using the drive, the information in the storage layer of the optical information recording medium is rewritten, the erasing means is erased by the recording device, the previous recording is erased, and the rewritten information is newly rewritten to the thermal layer by the thermal head, and the display recording is performed. did.
Further, this display record rewriting was repeated 100 times, but recording and erasing were possible.
[0127]
Example 15
The thermoreversible recording label of Example 14 was affixed onto a minidisc (MD) disc cartridge as shown in FIG.
Using a recording device having recording means (thermal head) and erasing means (ceramic heater), a part of information stored in the MD (date, date, song name, etc.) is used to record the recording energy of the thermal head of each medium. It was adjusted according to the change in recording temperature, recorded on the heat sensitive layer, and visualized.
Further, this display record rewriting was repeated 100 times, but recording and erasing were possible.
[0128]
Comparative Example 1
A thermoreversible recording medium was produced in the same manner as in Example 1 except that the coating solution for the heat sensitive layer was as follows.
Behenic acid (SIGMA reagent, purity 99%) 5 parts
Eicosanedioic acid (manufactured by Okamura Oil Co., Ltd., SL-20-90) 5 parts
38 parts of vinyl chloride-vinyl acetate copolymer
(VYHH, manufactured by Union Carbide)
Tetrahydrofuran 210 parts
20 parts of toluene
[0129]
Comparative Example 2
A thermoreversible recording medium was produced in the same manner as in Example 1 except that the coating solution for the heat sensitive layer was as follows.
In the heat-sensitive layer formed here, white particles were conspicuous and the uniformity was poor.
9.5 parts of behenate behenate (manufactured by Sigma, reagent)
Ethylene bisbehenamide 0.5 parts
(Nippon Kasei Co., Ltd., SLIPAX B)
30 parts of vinyl chloride-vinyl acetate copolymer
(VYHH, manufactured by Union Carbide)
160 parts of tetrahydrofuran
[0130]
Example 16
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0131]
Example 17
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0132]
Example 18
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0133]
Example 19
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0134]
Example 20
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0135]
Example 21
7 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 3 parts of the following compound was used.
Embedded image

[0136]
Example 22
A thermoreversible recording medium was produced in the same manner as in Example 16 except that behenyl behenate was changed to ethanolamine distearate (manufactured by Nippon Kasei Co., Ltd., Threide S).
[0137]
Example 23
A thermoreversible recording medium was prepared in the same manner as in Example 16 except that behenyl behenate was changed to diheptadecyl ketone (manufactured by Nippon Kasei Chemical Co., Ltd., wax KS).
[0138]
Example 24
9 parts behenyl behenate, CH_Three(CH₂)₁₇NHCOCONH (CH₂)₁₇CH_ThreeA thermoreversible recording medium was produced in the same manner as in Example 1 except that 0.5 part of each of the following two compounds was used.
CH_ThreeCH₂O (CH₂)_ThreeNHCO (CH₂)₁₁NHCONH (CH₂)₁₇CH_Three
Embedded image

[0139]
[Evaluation]
Using the thermoreversible recording media thus prepared (Examples 1 to 13, 16 to 24, Comparative Examples 1 and 2), the following evaluation was performed.
[0140]
contrast
The medium obtained as described above is made transparent in advance, and the print energy value of the thermal head is set to 0.47 mJ using a magnetic card reader / writer with print erasure function (KU-R-3001FA) manufactured by Kyushu Matsushita Electric. / Dot was applied with heat, cooled to room temperature, and the reflection density was measured with a Macbeth reflection densitometer, which was used as the initial image density.
Next, using the same apparatus, after forming a cloudy image on the medium with the above energy value, the erasing temperature value of the ceramic heater is set to 90 ° C., heat is applied, the temperature is cooled to room temperature, and the Macbeth reflection densitometer Then, the reflection density was measured, and this was used as the initial erase density.
Next, the initial contrast (initial erase density−initial image density) was calculated from the initial image density and the initial erase density obtained as described above.
[0141]
(2) Ammonia resistance
After immersing the previously clarified medium in an 8% aqueous solution of ammonium carbonate for 48 hours, the image density and erasing density were measured with the same apparatus and the same method used in the above contrast, The erasing density was taken after the test.
Next, the post-test contrast (post-test erase density−post-test image density) was calculated from the post-test image density and post-test erase density determined above.
[0142]
(3) Erasability
The medium was made transparent in advance, and after using a reader / writer (KU-R-3001FA) made by Kyushu Matsushita Electric Appliance to make it partially turbid in a thermal gradient tester under an environment of 5 ° C., the center of the erasing temperature Fifty sheets were erased at the optimum erasing temperature in the vicinity, and the erasure state of the image was visually determined.
Evaluation level
○: All can be erased.
○ to Δ: A small amount of unerased residue is generated.
Δ: Occasionally unerased.
X: Unerased frequently occurs.
Table 1 summarizes the results of (1) to (3).
(4) Clarification upper limit temperature (Ttu), Opaque (white turbidity) lower limit temperature (Tsl), Temperature difference between transparency upper limit temperature and white turbidization lower limit temperature (ΔTts), Clarification lower limit temperature (Ttl), Clarification temperature range (ΔTw)
Using the measurement method described above, Ttu, Tsl, ΔTts, Ttl, and ΔTw were measured. The results are summarized in Tables 3 and 4.
[0143]
[Table 1]

[0144]
[Table 2]

[0145]
[Table 3]

[0146]
[Table 4]

[0147]
【The invention's effect】
According to the present invention, sufficient turbidity can be obtained even when stored in the presence of a basic substance, the temperature range for transparency is widened, and an image with sufficient image erasability and high contrast even when the environmental temperature changes. And a thermoreversible recording medium, a member having an information storage unit, an image processing method, and an image processing apparatus that provide sufficient white turbidity are provided, and the contribution to the thermoreversible recording field is extremely large.
[Brief description of the drawings]
FIG. 1 is a diagram showing a change in transparency by a thermoreversible recording medium according to the present invention.
FIG. 2 is a diagram for explaining a maximum transparency temperature, a minimum whitening temperature, a transparency start temperature, and a transparency temperature range of the thermoreversible recording medium according to the present invention.
FIG. 3 is a diagram showing an example in which a thermoreversible recording label is attached to an MD disk cartridge.
FIG. 4 is a diagram showing an example in which a thermoreversible recording label is pasted on a CD-RW.
FIG. 5 is a view showing an example in which a thermoreversible recording label is formed on an optical information recording medium (CD-RW) using an AgInSbTe phase change type storage material.
FIG. 6 is a diagram showing a display label of a video tape cassette.
FIG. 7 is a diagram showing a layer configuration example of a thermoreversible recording medium according to the present invention.
FIG. 8 is a diagram showing an example of a thermoreversible recording medium according to the present invention.
FIG. 9 is a diagram showing another example of a thermoreversible recording medium according to the present invention.
FIG. 10 is a diagram showing a usage example of a thermoreversible recording medium according to the present invention.
FIG. 11 is a diagram showing an example of a thermoreversible recording apparatus according to the present invention.
[Explanation of symbols]
1 Thermoreversible recording medium
11 Support
12 Aluminum reflective layer
13 Reversible recording layer
14 Protective layer
15 Transparent PET film
16 Air layer
17 Adhesive layer
20 Magnetic coating layer
21 cards
22 Rewrite recording section
23 IC chip recess
24 Label processing of rewrite recording part
34 Magnetic head
38 Ceramic heater
40 Conveying roller
47 Conveyance roller
53 Thermal Head
231 wafer
232 Wafer substrate
233 integrated circuit
234 Contact terminal
235 CPU
236 ROM
237 RAM
238 I / O interface
239 RAM storage area information

Claims (20)

A thermoreversible recording medium comprising a support and a thermoreversible recording medium having a resin and an organic low-molecular substance as main components and a heat-sensitive layer that reversibly changes between a transparent state and an opaque state depending on temperature. As a thermoreversible recording medium, a linear hydrocarbon-containing compound (A) selected from the compounds described in 1) to 7) below and having no carboxyl group is used.
1) A linear hydrocarbon-containing compound having a urethane bond.
2) A linear hydrocarbon-containing compound having a sulfonyl bond.
3) A linear hydrocarbon-containing compound having an oxalic acid diamide bond.
4) A linear hydrocarbon-containing compound having a diacyl hydrazide bond.
5) A linear hydrocarbon-containing aliphatic compound having a urea bond and a urethane bond.
6) A linear hydrocarbon-containing aliphatic compound having a urea bond and an amide bond.
7) A linear hydrocarbon-containing aliphatic compound having a plurality of urea bonds. Among the linear hydrocarbon-containing compounds (A), the above 1) to 7) have at least one selected from a phenylene structure, a cyclohexylene structure, a cyclohexyl group, a phenyl group, and a heterocyclic ring. 2. The thermoreversible recording medium according to 1. The thermoreversible recording medium according to claim 1 or 2, wherein at least one of the molecular ends of the linear hydrocarbon-containing compound (A) is a methyl group. The thermoreversible recording medium according to any one of claims 1 to 3, wherein the linear hydrocarbon-containing compound (A) has a melting point of 100 ° C or higher. As the organic low molecular weight substance, at least one kind of the linear hydrocarbon-containing compound (B) having a melting point lower by 20 ° C. or more than the melting point of the linear hydrocarbon-containing compound (A) and having no carboxyl group The thermoreversible recording medium according to claim 1, which is used. 6. The thermoreversible recording medium according to claim 5, wherein the linear hydrocarbon-containing compound (A) and the linear hydrocarbon-containing compound (B) have 6 to 60 carbon atoms in total. The thermoreversible recording medium according to claim 5 or 6, wherein the linear hydrocarbon-containing compound (B) has a melting point of 50 ° C or higher and lower than 100 ° C. The mixing ratio of the linear hydrocarbon-containing compound (A) and the linear hydrocarbon-containing compound (B) is 80:20 to 1:99 by weight, according to any one of claims 5 to 7. Thermoreversible recording medium. The linear hydrocarbon-containing compound (B) is at least one selected from fatty acid esters, ketones having alkyl groups, dibasic acid esters, alcohol difatty acid esters, aliphatic monoamide compounds, and aliphatic monourea compounds. Item 9. The thermoreversible recording medium according to any one of Items 5 to 8. The heat according to any one of claims 1 to 9, which satisfies all of the following three conditions (i) to (iii) for reversibly changing the transparent state and the opaque state depending on the temperature: Reversible recording medium.
(I) The transparent upper limit temperature is 115 ° C. or higher.
(Ii) The temperature difference between the transparency upper limit temperature and the opacification lower limit temperature is 20 ° C. or less.
(Iii) The transparent temperature range is 30 ° C. or higher. The thermoreversible recording medium according to any one of claims 1 to 10, wherein the resin has a gel fraction of 30% or more. The thermoreversible recording medium according to any one of claims 1 to 9, wherein at least a part of the resin is crosslinked. A heat comprising an adhesive layer or a pressure-sensitive adhesive layer provided on a surface opposite to a surface forming a heat-sensitive layer of the support constituting the thermoreversible recording medium according to any one of claims 1 to 12. Reversible recording label. An information recording unit comprising an information storage unit and a reversible display unit, wherein the reversible display unit comprises at least a thermosensitive layer constituting the thermoreversible recording medium according to any one of claims 1 to 12. A member having The member having the information recording unit according to claim 14, wherein a reversible display unit is provided. The member having an information storage unit according to claim 14 or 15, wherein the member having the information storage unit is a card, a disk, a disk cartridge, or a tape cassette. The member which has an information storage part in any one of Claims 14-16 in which the reversible display part is provided using the thermoreversible recording label of this Claim 13. The thermoreversible recording medium according to any one of claims 1 to 12, the thermoreversible recording label according to claim 13, or the thermosensitive member constituting each member having the information storage unit according to any one of claims 14 to 17. An image processing method comprising forming and / or erasing an image by heating a layer. The image processing method according to claim 18, wherein an image is formed using a thermal head. The image processing method according to claim 18, wherein the image is erased using a thermal head or a ceramic heater.

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