JP4202508B2 - Thermal transfer image receiving sheet - Google Patents

Description

（但し、式中のＲ₁ 、Ｒ₂ 、Ｒ₃ はそれぞれアルキル基またはアリール基の何れかを表す。）
【００１８】
リン酸エステル化合物の可塑剤として、具体的には、例えば、トリメチルホスフェート、トリブチルホスフェート、トリエチルホスフェート、トリフェニルホスフェート、トリトリルホスフェート、トリキシレニルホスフェート、ジフェニルトリルホスフェート、フェニルジトリルホスフェート、ジフェニルキシレニルホスフェート、ジフェニルジキシレニルホスフェート、トリベンジルホスフェート、トリ（２−フェニルエチル）ホスフェート等が挙げられる。
また有機酸エステル系化合物では、フタル酸エステル化合物、脂肪族二塩基酸エステル系化合物のうちから選ばれる少なくとも１種であることが望ましい。
フタル酸エステル化合物は、下記式（２）で示される。
【化２】

（但し、式中のＲ₄ 、Ｒ₅ はそれぞれアルキル基またはアリール基の何れかを表す。）
【００１９】
フタル酸エステル化合物の可塑剤は、具体的には、例えば、ジメチルフタレート、ジエチルフタレート、ジブチルフタレート、ジオクチルフタレート（＝２−エチルヘキシルフタレート）、ジシクロヘキシルフタレート、ジフェニルフタレート等が挙げられる。
脂肪族二塩基酸エステル系化合物では、アジピン酸エステル系化合物、またはセバシン酸エステル系化合物が好ましく用いられる。アジピン酸エステル系化合物の可塑剤は、例えば、アジピン酸ジイソオクチル、アジピン酸ジイソデシル、アジピン酸ジオクチル、アジピン酸ジデシル、アジピン酸デシルイソオクチル等が挙げられる。
また、セバシン酸エステル系化合物の可塑剤は、例えば、セバシン酸ジオクチル、セバシン酸ジブチル等が挙げられる。
【００２０】
上記の可塑剤のうち、受容層に添加するものは、少なくとも１種はアリール基を１個以上含有した化合物または縮合物であることが望ましく、それを用いることにより、可塑化効果が高く、得られる印画物の高い発色濃度と耐光性の確保が両立できる。
以上の可塑剤と受容層樹脂との配合比は可塑剤の種類、スチレンホモポリマーの重合度等によって、相違するので一律に決定することは困難であるが、通常は受容層樹脂：可塑剤の重量比で５：５〜９：１程度である。
【００２１】
また、記録に用いる熱転写シートの染料等に応じて、濃度、鮮明性、あるいは各種保存性を改善するために、受容層樹脂として使用できる従来公知のスチレン系ポリマーを除く如何なる樹脂を更にブレンドすることができる。例えば、ポリウレタン系樹脂、ポリエステル系樹脂、ポリカーボネート系樹脂、ポリアミド系樹脂、アクリル系樹脂、セルロース系樹脂、ポリスルフォン系樹脂、塩化ビニル−酢酸ビニル共重合体，ポリ塩化ビニル樹脂、ポリ酢酸ビニル樹脂、ポリビニルアセタール樹脂、ポリビニルブチラール樹脂、ポリプロピレン系樹脂、ポリエチレン系樹脂、エチレン−酢酸ビニル共重合体、エポキシ樹脂等が挙げられる。
これらの樹脂のブレンド比は、スチレン系ホモポリマー１００部に対して、５〜５０部の範囲であることが好ましい。５部未満では添加による改質の効果が発現しにくく、一方、５０部を越えると、耐光性に優れるというスチレン系樹脂の特質が損なわれる。
このように他の樹脂を混合して用いる場合、ＯＨＰ用途など透明性を必要とする場合は、相溶性の良い樹脂を選択し用いる必要がある。
【００２２】
本発明の熱転写受像シートの受容層には、離型剤として、フッ素系界面活性剤及び／またはシリコーン樹脂あるいはその架橋物を含有させることが好ましい。
前記のシリコーン樹脂は、エポキシ変性シリコーン及び／または無変性シリコーンを用いるのが、より好ましい。また、そのエポキシ変性シリコーンは、シリコーンのシロキサン部位のケイ素部分に結合する置換基は、アルキレン基、アルキル基、アリール基、エーテル結合、エポキシ基の何れかである。
また、上記の無変性シリコーンは、シリコーンのシロキサン部位のケイ素部分に結合する置換基は、アルキレン基、アルキル基、アリール基、エーテル結合の何れかである。
また、シリコーン架橋物は、アミノ基含有シリコーン、カルボキシル基含有シリコーン、水酸基含有シリコーンから選ばれる少なくとも１種の活性水素含有シリコーンとイソシアネート化合物の架橋物でも、エポキシ変性シリコーンとアミノ基含有化合物の架橋物、アミノ変性シリコーンとエポキシ基含有化合物の架橋物、アミノ変性シリコーンとエポキシ変性シリコーンの架橋物、ビニル変性シリコーンと水素変性シリコーンの架橋物の何れであってもよい。
【００２３】
また、上記以外の離型剤で、従来用いられている離型剤を併用してもよく、離型剤を複数種類使用してもトータルで、添加量は受容層樹脂に対し０．１〜２０重量％が好ましい。
受容層にはその他にも、必要に応じて各種の添加剤を加えることができる。受容層の白色度を向上させ転写画像の鮮明度を更に高める目的で、酸化チタン、酸化亜鉛、カオリン、クレー、炭酸カルシウム、微粉末シリカ等の顔料や充填剤を添加することができる。但し、ＯＨＰ用途などの透明性を必要とする場合には、顔料や添加剤の添加量は、必要な透明性を失わない程度とする。
また、受容層には可塑剤、紫外線吸収剤、光安定剤、酸化防止剤、蛍光増白剤、帯電防止剤など公知の添加剤を必要に応じて加えることができる。
【００２４】
上記にあげた樹脂と、上記であげた可塑剤、離型剤と必要に応じて添加剤等を任意に添加し、溶剤、希釈剤等で、十分に混練して、受容層塗工液を製造し、これを、上記にあげた基材シートの上に、例えば、グラビア印刷法、スクリーン印刷法、グラビア版を用いたリバースロールコーティング法等の形成手段により、塗布し、乾燥して、受容層を構成する。
後述する中間層、裏面層、易接着層及び帯電防止層の塗工も、上記の受容層の形成手段と同様の方法で行われる。
また、帯電防止性を付与させるために、下記に示す帯電防止剤を受容層塗工液に、練り込むこともできる。
帯電防止剤；脂肪酸エステル、硫酸エステル、リン酸エステル、アミド類、４級アンモニウム塩、ベタイン類、アミノ酸類、アクリル系樹脂、エチレンオキサイド付加物など。
帯電防止剤の添加量は、樹脂に対し、０．１〜２．０重量％が好ましい。
【００２５】
本発明の熱転写受像シートでは、受容層の塗工量は、乾燥時重量で０．５ｇ／ｍ² 〜１０．０ｇ／ｍ² であることが好ましい。塗工量が乾燥時重量で０．５ｇ／ｍ² 未満では、例えば、基材シート上に直接受容層を設けた場合には、基材シートの剛性等の要因でサーマルヘッドとの密着が不十分なためハイライト部の画像がざらついてしまうという問題がある。この問題は、クッション性を付与する中間層を設けることで回避することができるが、受容層の傷つきに対して弱くなる。また、高エネルギーを印加したときの表面の荒れかたは、受容層の塗工量が増加すると相対的に悪くなる傾向があり、塗工量が、乾燥時重量で１０．０ｇ／ｍ² を越えると、例えば、ＯＨＰ投影時の高濃度部でわずかに黒ずんでみえるようになる。
以下本発明の塗工量（ないし塗布量）は、特に断りのない限り、乾燥時重量で、固形分換算の数値である。
【００２６】
（中間層）
本発明においては、基材シートと受容層の間に各種の樹脂からなる中間層を設けることもできる。このような中間層は、基材シートと受容層との接着性、白色度、クッション性、隠蔽性、帯電防止性、カール防止性等の付与を目的として、従来公知のあらゆる中間層を設けることができる。
中間層に用いるバインダー樹脂としては、ポリウレタン系樹脂、ポリエステル系樹脂、ポリカーボネート系樹脂、ポリアミド系樹脂、アクリル系樹脂、ポリスチレン系樹脂、ポリスルフォン系樹脂、ポリ塩化ビニル樹脂、ポリ酢酸ビニル樹脂、塩化ビニル−酢酸ビニル共重合体、ポリビニルアセタール樹脂、ポリビニルブチラール樹脂、ポリビニルアルコール樹脂、エポキシ樹脂、セルロース系樹脂、エチレン−酢酸ビニル共重合体、ポリエチレン系樹脂、ポリプロピレン系樹脂等が挙げられ、これらの樹脂のうちの活性水素を有するものについては、さらにそれらのイソシアネート架橋物をバインダーとすることもできる。
【００２７】
また、白色性、隠蔽性を付与するために、酸化チタン、酸化亜鉛、炭酸マグネシウム、炭酸カルシウム等のフィラーを添加することが好ましい。
さらに、白色性を高めるために、スチルベン系化合物、ベンゾイミダゾール系化合物、ベンゾオキサゾール系化合物等を蛍光増白剤として添加したり、印画物の耐光性を高めるために、ヒンダードアミン系化合物、ヒンダードフェノール系化合物、ベンゾフェノン系化合物、ベンゾトリアゾール系化合物等を紫外線吸収剤、あるいは酸化防止剤として添加したり、あるいは帯電防止性を付与するために、カチオン系アクリル樹脂、ポリアニリン樹脂、各種導電性フィラー等を添加することができる。
【００２８】
（裏面層）
基材シートの受容層を設けた面と反対の面に、熱転写受像シートの搬送適性、筆記性、帯電防止性、耐汚染性、カール防止性等の付与の目的で、従来公知のあらゆる裏面層を設けることができる。
裏面層として、例えば、アクリル系樹脂、セルロース系樹脂、ポリカーボネート樹脂、ポリビニルアセタール樹脂、ポリビニルアルコール樹脂、ポリアミド樹脂、ポリスチレン系樹脂、ポリエステル系樹脂、ハロゲン化ポリマー等の樹脂中に、添加剤として、アクリル系フィラー、ポリアミド系フィラー、フッ素系フィラー、ポリエチレンワックスなどの有機系フィラー、及び二酸化珪素や金属酸化物などの無機フィラーを加えたものが使用できる。
この裏面層として、上述の樹脂を硬化剤により硬化したものを使用することが好ましい。硬化剤としては、一般的に公知のものが使用できるが、中でもイソシアネート化合物が好ましい。裏面層樹脂はイソシアネート化合物などと反応しウレタン結合を形成して硬化・立体化することにより、耐熱保存性、耐溶剤性が向上し、さらには、基材シートとの密着も良くなる。硬化剤の添加量は、樹脂１反応基当量に対して、１乃至５が好ましい。１未満であると、硬化終了するまでの時間が長くかかり、また、耐熱性、耐溶剤性が悪くなる。また、５より大きいと、成膜後に経時変化が起こったり、裏面層用塗工液の寿命が短いという不具合が生じる。
【００２９】
さらに、上記裏面層中には、添加剤として、有機フィラーまたは無機フィラーを添加しても良い。これらのフィラーの働きで、プリンター内での熱転写受像シートの搬送性が向上し、また、ブロッキングを防ぐなど熱転写受像シートの保存性も向上する。
有機フィラーとして、アクリル系フィラー、ポリアミド系フィラー、フッ素系フィラー、ポリエチレンワックスなどがあげられる。この中では、特にポリアミド系フィラーが好ましい。また、無機フィラーとして、二酸化珪素や金属酸化物などがあげられる。
ポリアミド系フィラーとしては、分子量が１０万乃至９０万で、球状であり、平均粒子径が０．０１乃至３０μｍが好ましく、特に分子量が１０万乃至５０万で、平均粒子径が０．０１乃至１０μｍがより好ましい。また、ポリアミド系フィラーの種類では、ナイロン６やナイロン６６と比較して、ナイロン１２フィラーが耐水性に優れ、吸水による特性変化がないためより好ましい。
【００３０】
ポリアミド系フィラーは、高融点で熱的にも安定であり、耐油性、耐薬品性なども良く、染料によって染着されにくい。また、分子量が１０万乃至９０万であると磨耗することもほとんどなく、自己潤滑性があり、摩擦係数も低く、擦れる相手を傷つけにくい。
また、好ましい平均粒子径は、反射画像用熱転写受像シートの場合、０．１乃至３０μｍであり、透過画像用熱転写受像シート（ＯＨＰ用シート）の場合、０．０１乃至１μｍである。粒子径が小さすぎると、フィラーが裏面層中に隠れてしまい、十分な滑り性の機能が発現され難くなる傾向がみられ、また、粒子径が大きすぎると、裏面層からの突出が大きくなり、結果的に摩擦係数を高めたり、フィラーの欠落を生じる傾向があるので、好ましくない。
裏面層の樹脂に対するフィラーの配合比率は、０．０１重量％乃至２００重量％の範囲が好ましい。反射画像用熱転写受像シートの場合は、１重量％乃至１００重量％がより好ましく、透過画像用熱転写受像シートの場合は、０．０５重量％乃至２重量％がより好ましい。フィラーの配合比率が０．０１重量％未満の場合には、滑り性が不十分であり、プリンターの給紙時などで紙詰まりなどの支障をきたす傾向が生じる。また、２００重量％を越える場合には、滑りすぎて印字画像に色ずれなどが生じやすくなるため、好ましくない。
【００３１】
（易接着層）
基材シートの表面および／または裏面に、アクリル酸エステル樹脂やポリウレタン樹脂やポリエステル樹脂などの接着性樹脂からなる易接着層を塗布して設けてもよい。また、上記に記載した塗布層を設けずに、基材シートの表面および／または裏面に、コロナ放電処理やプラズマ処理をして、基材シートとその上に設ける層との接着性を高めることができる。
【００３２】
（帯電防止層）
基材シートの表面および／または裏面に、もしくは、熱転写受像シートの受像面もしくは裏面もしくはその両面の最表面に帯電防止層を設けてもよい。帯電防止層は、帯電防止剤である、脂肪酸エステル、硫酸エステル、リン酸エステル、アミド類、４級アンモニウム塩、ベタイン類、アミノ酸類、アクリル系樹脂、エチレンオキサイド付加物等を溶剤に溶解又は分散させたものを塗工して、形成することができる。
その塗工量は０．１ｇ／ｍ² 乃至５．０ｇ／ｍ² であることが好ましい。但し、最表面に設ける場合は、０．００１ｇ／ｍ² 乃至０．１ｇ／ｍ² が好ましい。
このように、最表面に帯電防止層を設けた熱転写受像シートは、印画前に優れた帯電防止性を有するため、ダブルフィード等の給紙不良を防止することができる。また、ほこり等を寄せつけることによる印画抜け等のトラブルを防止することができる。
【００３３】
本発明では、上記に説明した熱転写受像シートの受容層に染料画像が形成された印画物において、該染料画像上の少なくとも一部に保護層を転写して設けることが好ましく行われる。
具体的には、上記の熱転写受像シートの受容層に、染料層が基材上に形成された熱転写シートより昇華染料を熱転写して画像を形成し、その画像上の少なくとも一部に、基材上に転写性樹脂層（保護層）を設けた保護層転写シートを用いて、この転写性樹脂層を熱転写して、保護層を転写形成するものである。
上記の染料層を有する熱転写シートと、保護層転写シートは従来公知のものが使用でき、限定されるものではない。尚、イエロー、マゼンタ、シアン等の染料層と転写性保護層を面順次に設けた熱転写シートを使用することも可能である。
【００３４】
また、基材シートの一方の面に受容層を設け、基材シートの他方の面に粘着剤などを用いた接着剤層と剥離紙を順に設けた、シールタイプの熱転写受像シートについても、本発明を適用することができる。その接着剤層の形成手段も上記受容層の形成手段と同様の方法で行われる。
さらに、染料受容層を基材上に剥離可能に形成した受容層転写シートにおける受容層についても、本発明を適用することができる。
また、まず、染料受容層が基材上に剥離可能に設けられた中間転写記録媒体の受容層に、染料層が基材上に形成された熱転写シートより昇華染料を転写して画像を形成し、その後に中間転写記録媒体を加熱して、画像形成された受容層を被転写体上に転写する方式においても、その受容層に本発明を適用することができる。
【００３５】
【実施例】
以下に、実施例及び比較例を示し、本発明を詳述する。尚、文中に部または％とあるのは、特に断りのない限り重量基準である。
（実施例１）
基材シートとして、厚さ１５０μｍの合成紙（王子油化株式会社製、ＹＵＰＯＦＰＧ＃１５０）を用い、その一方の面に下記組成の白色中間層塗工液をグラビアコート方式で乾燥時２．０ｇ／ｍ² になるように、塗布及び乾燥させて、中間層を形成した。次いで、上記の中間層の上に、下記組成の受容層塗工液１をグラビアコート方式で乾燥時５．０ｇ／ｍ² になるように、塗布及び乾燥させて、受容層を形成し、実施例１の熱転写受像シートを得た。
【００３６】
白色中間層塗工液
ポリエステル樹脂（日本合成化学工業（株）製、ＷＲ−９０５） ２５部
水溶性蛍光増白剤（チバガイギー社製、Ｕｖｉｔｅｘ ＢＡＣ） １部
酸化チタン（トーケムプロダクツ社製、ＴＣＡ−８８８） ７５部
水／イソプロピルアルコール（重量混合比１／１） ４００部
【００３７】
受容層塗工液１
ポリスチレン樹脂（重量平均分子量１００，０００） ７０部
ジシクロヘキシルフタレート ３０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００３８】
（実施例２）
受容層塗工液を下記組成の受容層塗工液２に変え、その他は実施例１と同様にして、実施例２の熱転写受像シートを得た。
受容層塗工液２
ポリスチレン樹脂（重量平均分子量５０，０００） ７０部
ジフェニルフタレート ３０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００３９】
（実施例３）
受容層塗工液を下記組成の受容層塗工液３に変え、その他は実施例１と同様にして、実施例３の熱転写受像シートを得た。
受容層塗工液３
ポリスチレン樹脂（重量平均分子量２５０，０００） ８５部
ジオクチルフタレート １５部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４０】
（実施例４）
受容層塗工液を下記組成の受容層塗工液４に変え、その他は実施例１と同様にして、実施例４の熱転写受像シートを得た。
受容層塗工液４
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
ジシクロヘキシルフタレート ２０部
ジオクチルアジペート １０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４１】
（実施例５）
受容層塗工液を下記組成の受容層塗工液５に変え、その他は実施例１と同様にして、実施例５の熱転写受像シートを得た。
受容層塗工液５
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
ジシクロヘキシルフタレート ３０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
アミノ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−１６６０−Ｂ３）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４２】
（実施例６）
受容層塗工液を下記組成の受容層塗工液６に変え、その他は実施例１と同様にして、実施例６の熱転写受像シートを得た。
受容層塗工液６
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
トリフェニルホスフェート ３０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４３】
（実施例７）
受容層塗工液を下記組成の受容層塗工液７に変え、その他は実施例１と同様にして、実施例７の熱転写受像シートを得た。
受容層塗工液７
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
トリフェニルホスフェート ３０部
無変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２４−５１０）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４４】
（実施例８）
受容層塗工液を下記組成の受容層塗工液８に変え、その他は実施例１と同様にして、実施例８の熱転写受像シートを得た。
受容層塗工液８
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
トリフェニルホスフェート ３０部
無変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２４−５１０）
水酸基変性シリコーン ２部
（信越化学工業（株）製、Ｘ−６２−１６０ＡＳ）
イソシアネート化合物 １部
（ＸＤＩ、武田薬品工業（株）製、タケネート Ａ−１４）
ジブチル錫ジラウレート ０．０１部
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４５】
（実施例９）
受容層塗工液を下記組成の受容層塗工液９に変え、その他は実施例１と同様にして、実施例９の熱転写受像シートを得た。
受容層塗工液９
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
芳香族縮合リン酸エステル ３０部
（大八化学工業（株）製、ＣＲ−７３３Ｓ）
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４６】
（実施例１０）
受容層塗工液を下記組成の受容層塗工液１０に変え、その他は実施例１と同様にして、実施例１０の熱転写受像シートを得た。
受容層塗工液１０
ポリスチレン樹脂（重量平均分子量２５０，０００） ７０部
芳香族縮合リン酸エステル ３０部
（大八化学工業（株）製、ＣＲ−７３３Ｓ）
フッ素系界面活性剤（３Ｍ社製、ＦＣ４３１） ５部
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４７】
（比較例１）
受容層塗工液を下記組成の受容層塗工液１１に変え、その他は実施例１と同様にして比較例１の熱転写受像シートを得た。
受容層塗工液１１
塩化ビニル−酢酸ビニル共重合体 １００部
（電気化学工業（株）製、＃１０００Ａ）
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
無変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２４−５１０）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４８】
（比較例２）
受容層塗工液を下記組成の受容層塗工液１２に変え、その他は実施例１と同様にして比較例２の熱転写受像シートを得た。
受容層塗工液１２
ポリビニルブチラール樹脂 ８５部
（電気化学工業（株）製、＃３０００−１）
ジフェニルフタレート １５部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００４９】
（比較例３）
受容層塗工液を下記組成の受容層塗工液１３に変え、その他は実施例１と同様にして比較例３の熱転写受像シートを得た。
受容層塗工液１３
ポリカーボネート樹脂 ７０部
（出光石油化学（株）製、タフタロン Ａ２５００）
ジフェニルフタレート ３０部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
クロロホルム ４００部
【００５０】
（比較例４）
受容層塗工液を下記組成の受容層塗工液１４に変え、その他は実施例１と同様にして比較例４の熱転写受像シートを得た。
受容層塗工液１４
ポリスチレン樹脂（重量平均分子量２５０，０００） １００部
エポキシ変性シリコーン ５部
（信越化学工業（株）製、Ｘ−２２−３０００Ｔ）
メチルエチルケトン／トルエン（重量混合比１／１） ４００部
【００５１】
このように得られた熱転写受像シートの染料受容層と、熱転写シート（三菱電機（株）製ビデオプリンターＣＰ−７００用熱転写シートＣＫ７００Ｌ４Ｐ）の染料層とを対向させて重ね合わせ、イエロー、マゼンタ、シアンの各色について、熱転写シートの裏面から下記条件でサーマルヘッドを用いて、熱転写記録を行い、その後に下記条件で熱転写画像上に保護層を転写し、以下の各種評価を行った。
【００５２】
（印字条件）
サーマルヘッド；ＫＧＴ−２１７−１２ＭＰＬ２０（京セラ（株）製）
発熱体平均抵抗値；３１９５（Ω）
主走査方向印字密度；３００ｄｐｉ
副走査方向印字密度；３００ｄｐｉ
印加電力；０．１２（ｗ／ｄｏｔ）
１ライン周期；５（ｍｓｅｃ．）
印字開始温度；４０（℃）
階調制御方法；１ライン周期中に、１ライン周期を２５６に等分割したパルス長をもつ分割パルスの数を０から２５５個まで可変できるマルチパルス方式のテストプリンターを用い、各分割パルスのＤｕｔｙ比を６０％固定とし、階調によってライン周期当たりのパルス数を０ステップでは０個、１ステップでは１７個、２ステップでは３４個と０から２５５個まで１７個毎に順次増加させることにより、０ステップから１５ステップまでの１６階調を制御した。
尚、保護層については、分割パルスの数を２５５個に固定して転写を行った。
【００５３】
（印字前耐熱性）
実施例及び比較例の各熱転写受像シートを２枚ずつ用意し、１枚を常温に、他の１枚を６０℃のオーブン中にそれぞれ１００時間保存し、それぞれの熱転写受像シートについて、上記の熱転写シートを用い、上記印字条件でイエロー、マゼンタ、シアンの各色のグラデーションを印字した。
得られたそれぞれの印字物について、各ステップ毎の光学反射濃度を光学濃度計（マクベス社製、マクベスＲＤ−９１８）で測定した。
得られた各色、各ステップの光学反射濃度について、常温で保存した熱転写受像シートの印字物の光学反射濃度の実測値を〔ＯＤ〕₀ とし、６０℃、１００時間保存した熱転写受像シートの印字物の光学反射濃度の実測値を〔ＯＤ〕₁ とし、対応する各色、各ステップについて、下記式により、印字前の耐熱性試験によるγ特性の変化率を算出した。
【００５４】
変化率（％）＝（〔ＯＤ〕₁ −〔ＯＤ〕₀ ）×１００／〔ＯＤ〕₀
各色、各ステップで最も大きな値を示した変化率を、その熱転写受像シートの印字前耐熱性を示すものとして、下記の基準に基づき判定した。
○；変化率が１０％未満であり、印字前耐熱性に優れている。
△；変化率が１０％以上、２０％未満であり、印字前耐熱性が少し劣る。
×；変化率が２０％以上であり、印字前耐熱性が劣る。
【００５５】
（耐光性）
各実施例および比較例の熱転写受像シートを前記の熱転写シートで、前記の印字条件にて、熱転写記録を行い、シアン色について下記条件で耐光性試験を行った。
照射試験器；アトラス社製Ｃｉ１３５
光源；キセノンランプ
フィルター；内側・・・ＩＲフィルター、外側・・・ソーダライムガラス
ブラックパネル温度；４５℃
照射強度；１．２（ｗ／ｍ² ）・・・４２０ｎｍでの測定値
照射エネルギー；２００（ＫＪ／ｍ² ）・・・４２０ｎｍでの積算値
【００５６】
照射前の光学反射濃度が１．０近傍のステップについて、照射の前後における光学濃度の変化を測定し、下記式により、残存率を算出した。
残存率（％）＝（〔照射後の光学反射濃度〕／〔照射前の光学反射濃度〕）×１００
以上の残存率に基づき、以下に基準にて耐光性を判定した。
○；残存率が８０％以上であり、耐光性が優れている。
△；残存率が７０％以上、８０％未満であり、耐光性がほぼ良好である。
×；残存率が７０％未満であり、耐光性が不良である。
【００５７】
（耐熱性）
各実施例および比較例の熱転写受像シートを、前記の熱転写シートで、前記の印字条件にて、熱転写記録を行い、得られた印字物を６０℃のオーブン中に１００時間放置し、画像の滲みを２５倍のルーペで観察し、下記基準にて判定した。
○；印字物の画像ドットサイズに大きな変化が認められなかった。
△；ドットの拡散は認められたが、目視では明確な滲みは認められなかった。
×；未印字の部分にも色素が拡散し、目視でも明確な滲みが認められた。
【００５８】
（印字濃度）
各実施例および比較例の熱転写受像シートを、前記の熱転写シートで、前記の印字条件にて、熱転写記録を行い、得られた印字物の光学反射濃度を測定し、下記の基準にて印字濃度の評価の判定をした。
○；比較例１の印字濃度を基準とした時、光学反射濃度がＯＤ値１付近で９０％以上である。
×；比較例１の印字濃度を基準とした時、光学反射濃度がＯＤ値１付近で９０％未満である。
【００５９】
（離型性）
各実施例および比較例の熱転写受像シートを、前記の熱転写シートで、前記の印字条件にて、熱転写記録を行い、熱転写受像シートと熱転写シートとの離型性を下記基準にて、判定した。
○；熱転写受像シートと熱転写シートとが容易に剥離し、異常転写等の発生が無く、離型性が良好である。
×；熱転写受像シートと熱転写シートとが融着したり、異常転写等が発生し、離型性が不良である。
【００６０】
（保護層接着性）
各実施例および比較例の熱転写受像シートを、前記の熱転写シートで、前記の印字条件にて、熱転写記録を行い、その後に前記の転写条件で熱転写画像上に保護層を転写した。その得られた印字物の転写された保護層上に、セロハンテープを貼り、剥離角度１８０°にてテープを剥がす剥離試験を行い、下記基準にて保護層接着性を判定した。
○；テープ側に保護層等印字物から剥がれるものがなく、保護層が熱転写受像シート上に充分に密着し、保護層接着性が良好である。
×；テープにより、保護層が熱転写受像シートから剥がれてしまい、保護層接着性が不良である。
【００６１】
（評価結果）
評価結果を下記の表１に示す。
【表１】

【００６２】
本発明によれば、以上説明したように、基材シートの少なくとも一方の面に染料受容層を形成してなる熱転写受像シートにおいて、該受容層がポリスチレン樹脂と分子量２５０〜１０００の無機酸エステル系化合物、有機酸エステル系化合物のうちから選ばれる少なくとも１種の化合物及び／または縮合物の可塑剤を含有させることで、熱転写の印字速度の高速化に対応して、記録感度が高く、充分な印字濃度が得られ、画像鮮明性が高く、また記録された画像の各種耐久性、保存安定性で、特に耐光性に優れた熱転写受像シートが得られた。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal transfer image-receiving sheet, and in a thermal transfer recording method using a sublimation dye, the recording sensitivity is high, a sufficient print density is obtained, and a recorded image can be obtained in response to an increase in thermal transfer printing speed. In particular, the present invention relates to a thermal transfer image-receiving sheet having excellent durability and storage stability.
[0002]
[Prior art]
Conventionally, various thermal transfer recording methods are known. Among them, thermal transfer having a dye layer in which a dye for sublimation transfer is used as a recording material and this is supported on a base sheet such as a polyester film with an appropriate binder. A method for forming various full-color images by thermally transferring a sublimation dye from a sheet onto a transfer object that can be dyed with a sublimation dye, for example, a thermal transfer image-receiving sheet on which a dye-receiving layer is formed on paper or plastic film is proposed. ing.
[0003]
In this case, as the heating means, a color dot in which a large number of three or four colors are adjusted by a heating medium such as a thermal head of a printer or a laser is transferred to the receiving layer of the thermal transfer image receiving sheet, and the multicolor The full color of the original is reproduced with the color dots.
The image formed in this way is very clear and excellent in transparency because the coloring material used is a dye, so the resulting image is excellent in the reproducibility and gradation of intermediate colors, It is possible to form a high-quality image similar to an image obtained by offset printing or gravure printing and comparable to a full-color photographic image.
[0004]
[Problems to be solved by the invention]
In recent years, as the printing speed of thermal transfer printers has increased, it has become impossible to obtain sufficient print density and weather resistance of printed matter with conventional thermal transfer recording materials.
As conventional techniques for thermal transfer image-receiving sheets, for example, in JP-A-57-1639370, JP-A-60-25793, etc., vinyl resins such as polycarbonate resins, polyvinyl butyral resins, polyester resins, polyvinyl chloride resins, It is disclosed that a dye-receiving layer is formed using a cellulose resin, an acrylic resin, an olefin resin, a polystyrene resin, or the like.
In the thermal transfer image receiving sheet as described above, the dye transfer sensitivity of the dye receiving layer and the various durability and storage stability of the image formed by the thermal transfer depend greatly on the binder resin forming the dye receiving layer.
In particular, the light resistance of the formed image largely depends on the composition structure of the receiving layer resin, and it is necessary to select an optimal resin composition. One resin having excellent light resistance is a styrene resin, and various styrene resins are disclosed in Japanese Patent Application Laid-Open No. 62-189195.
[0005]
In addition, as a means to improve the transfer sensitivity of the dye, it is only necessary to improve the diffusibility of the dye at the time of thermal transfer. There are ways to do this.
However, the conventional thermal transfer image receiving sheet as described above has the following problems.
In addition to the above-mentioned styrene resins, examples of the receiving layer resin having excellent light resistance include polycarbonate resins and polyvinyl acetal resins, but since any of these resins has a high glass transition temperature, sufficient dye dyeing properties can be obtained. I can't get it.
[0006]
In addition, in order to obtain sufficient dyeing property, when the method of adding a plasticizer to the receiving layer as described above is used, if the structure and physical properties of the plasticizer are not optimal with respect to the receiving layer resin, The compatibility between the layer resin and the plasticizer is impaired, and the following problems occur.
-After forming the receiving layer, the plasticizer and the resin having a low glass transition temperature bleed out over time, and the transferability and diffusibility of the dye change, so the recording sensitivity also changes over time.
If the compatibility between the receiving layer resin and the plasticizer is worse, the dye fixing property is not sufficient, bleeding occurs in the image area at the time of recording, or tacking occurs in the receiving layer, peeling from the thermal transfer sheet In some cases, printing may not be possible.
Even if there is no abnormality during recording, the recorded image is blurred or the light resistance of the image is impaired due to bleed-out after recording (particularly during high-temperature storage).
Accordingly, the object of the present invention is to achieve high recording sensitivity, sufficient print density, high image sharpness, in correspondence with the increase in the thermal transfer printing speed in the thermal transfer recording method using a sublimable dye, Another object of the present invention is to provide a thermal transfer image-receiving sheet having various durability and storage stability of recorded images, and particularly excellent in light resistance.
[0007]
[Means for Solving the Problems]
  In the present invention, in order to achieve the above object, as a result of extensive research, a thermal transfer image-receiving sheet in which a dye-receiving layer is formed on at least one surface of a base sheet,Polystyrene resinAnd at least one compound selected from an inorganic acid ester compound having a molecular weight of 250 to 1000 and an organic acid ester compound and / or a plasticizer of a condensate has been successfully solved. did. In the inorganic acid ester compound, a phosphoric acid ester compound is preferable, and the organic acid ester compound is at least one selected from a phthalic acid ester compound and an aliphatic dibasic acid ester compound. desirable. The aliphatic dibasic acid ester compound is preferably a sebacic acid ester compound or an adipic acid ester compound.
[0008]
In order to obtain a thermal transfer image-receiving sheet capable of forming a recorded image with excellent light resistance, a styrene resin, polycarbonate resin, polyvinyl acetal resin, etc., having a relatively high glass transition temperature must be used for the receiving layer resin. I must. However, when these resins are used, high recording sensitivity cannot be obtained.
Therefore, a plasticizer is added to the receiving layer in order to improve the recording sensitivity. The point to be noted here is the compatibility between the receiving layer resin and the plasticizer.
Addition of a plasticizer to a polycarbonate-based resin is generally performed well, and the compatibility between the resin and the plasticizer is high. However, a large amount of a release agent is required to ensure release properties from the thermal transfer sheet. It is necessary to add, and the dyeing | staining inhibition by a mold release agent arises, and a transfer density cannot be made high.
Polyvinyl acetal resins have low compatibility with commonly used plasticizers and are not suitable for plasticizer addition.
[0009]
In the present invention, when a styrene homopolymer is used in the dye-receiving layer, there are a phosphoric acid ester compound and a phthalic acid ester compound as plasticizers that are excellent in compatibility with the resin and have a high plasticizing effect. , Ensuring both high color density and light resistance.
In addition, as those having a slightly lower compatibility and less plasticizing effect than these plasticizers, there may be mentioned aliphatic dibasic acid ester compounds such as sebacic acid ester compounds and adipic acid ester compounds, which are thermal transfer sheets. It has the effect of improving the releasability with the dye layer, that is, reducing the heat-fusibility between the receiving layer resin and the dye layer resin, and is effective as a release aid when used in combination with the plasticizer. To do. Further, when two or more kinds of plasticizers are used in combination, there is an effect that bleeding out of the plasticizer with time is less likely to occur, and this is an effective means for improving the storage stability as an image receiving sheet.
[0010]
In addition, since the styrene resin contains a styrene skeleton, resins used for dye binders, for example, cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose butyrate, polyvinyl alcohol And low compatibility with vinyl resins such as polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone and polyacrylamide, or polyester resins. In other words, when a styrenic resin is used for the receiving layer, the releasability between the dye layer of the thermal transfer sheet and the receiving layer of the thermal transfer image receiving sheet during printing is excellent.
Therefore, sufficient releasability can be obtained with addition of a small amount of release agent, and since there is almost no dyeing inhibition by the release agent, a higher color density can be obtained.
[0011]
For the purpose of improving the fingerprint resistance and plasticizer resistance of printed matter, there is a method of transferring a protective layer to the image area after image formation, but it is necessary to add a large amount of a release agent like polycarbonate. , It is not suitable for such protective layer transfer. In order to obtain a thermal transfer image-receiving sheet that can be used in various applications, it is necessary to consider the addition amount of such a release agent.
Therefore, using a styrene homopolymer and using a dye-receiving layer capable of minimizing the addition amount of a release agent is important in applying to various uses of thermal transfer image-receiving sheets. .
Accordingly, the dye-receiving layer contains at least one compound selected from a styrene polymer, an inorganic acid ester compound having a molecular weight of 250 to 1000, and an organic acid ester compound and / or a condensate plasticizer. Has been found to be optimal in achieving the above-mentioned purpose.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
(Base material sheet)
It is desirable that the base sheet has a role of holding the receiving layer and has mechanical characteristics that can withstand heat applied during image formation and that does not hinder handling. The material of such a base sheet is not particularly limited. For example, polyester, polyarylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene / vinyl acetate copolymer, polypropylene, polystyrene, acrylic, Polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene / perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene・ Various plastic films such as hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride, etc. Over door it can be used is not particularly limited. For OHP applications, a transparent sheet can be selected and used.
[0013]
Standard types include those listed above, white films formed by adding white pigments and fillers to these synthetic resins, or foamed foam sheets, as well as condenser paper, glassine paper, sulfuric acid paper, synthetic paper ( Polyolefin, polystyrene), fine paper, art paper, coated paper, cast coated paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, cellulose fiber paper, and the like.
Moreover, the laminated body by arbitrary combinations of said base material sheet can also be used. Typical examples include a laminate of cellulose fiber paper and synthetic paper, and cellulose fiber paper and a plastic film.
[0014]
Moreover, the base material sheet which carried out the easy adhesion process on the surface and / or the back surface of said base material sheet can also be used.
In the present invention, an antistatic treatment is carried out from the above base sheet or the above base sheet, and 1.0 × 10 6 under an environment of a temperature of 20 ° C. and a relative humidity of 50%.¹²It is preferable to use a substrate sheet having a surface electrical resistivity of Ω / □ or less. By using such a base sheet, it is possible to prevent the occurrence of troubles due to static electricity during the production of the thermal transfer image receiving sheet, and as will be described later as a preferred embodiment in the present invention, the image receiving surface and the back surface of the thermal transfer image receiving sheet are used. The effect of the antistatic agent applied can be enhanced.
The thickness of these substrate sheets is usually about 30 to 300 μm. In the present invention, it is preferable to use a substrate sheet of 75 to 175 μm in consideration of mechanical suitability and the like. Moreover, when the adhesiveness of a base material sheet and the layer provided on it is scarce, it is preferable to perform easy adhesion processing, such as a primer process, a corona discharge process, or a plasma process, on the surface.
[0015]
(Receptive layer)
The receptor layer of the present invention is a receptor layer containing at least one kind of thermoplastic resin on at least one surface of the base sheet, and receives the sublimation dye transferred from the thermal transfer sheet, and is formed by thermal transfer. It is for maintaining images.
A styrene monomer is used as the thermoplastic resin of the receiving layer.
That is, the receiving layer resin is a styrene homopolymer obtained by polymerizing a styrene monomer alone, has excellent light resistance and heat resistance, and has sufficient transparency.
The styrene homopolymer preferably has a molecular weight of about 10,000 to 500,000 in terms of weight average.
[0016]
Further, at least one compound selected from an inorganic acid ester compound and an organic acid ester compound having a molecular weight of 250 to 1000 and / or a plasticizer of a condensate is used as an additive for the receiving layer.
The reason why the molecular weight of the plasticizer is specified as described above is that, by using a plasticizer having a relatively low molecular weight of 250 to 1000, compatibility with the styrene homopolymer is improved, recording sensitivity is high, and sufficient printing is performed. It is possible to obtain a thermal transfer image-receiving sheet having high density, high image sharpness, and excellent durability and storage stability, particularly light resistance, of recorded images.
When the molecular weight of the plasticizer is less than 250, the plasticizer tends to bleed out to the surface of the receiving layer. On the other hand, when the molecular weight exceeds 1000, the compatibility of the receiving layer resin with the styrene homopolymer decreases. .
[0017]
As the plasticizer, a phosphoric acid ester compound is particularly preferably used as the inorganic acid ester compound.
The phosphate ester compound is represented by the following formula (1).
[Chemical 1]

(However, R in the formula₁, R₂, R_ThreeEach represents an alkyl group or an aryl group. )
[0018]
Specific examples of the plasticizer for the phosphoric acid ester compound include trimethyl phosphate, tributyl phosphate, triethyl phosphate, triphenyl phosphate, tolyl tol phosphate, trixylenyl phosphate, diphenyl tolyl phosphate, phenylditolyl phosphate, diphenyl xylate. Nyl phosphate, diphenyldixylenyl phosphate, tribenzyl phosphate, tri (2-phenylethyl) phosphate and the like can be mentioned.
The organic acid ester compound is preferably at least one selected from a phthalic acid ester compound and an aliphatic dibasic acid ester compound.
The phthalic acid ester compound is represented by the following formula (2).
[Chemical 2]

(However, R in the formula_Four, R_FiveEach represents an alkyl group or an aryl group. )
[0019]
Specific examples of the plasticizer for the phthalic acid ester compound include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate (= 2-ethylhexyl phthalate), dicyclohexyl phthalate, and diphenyl phthalate.
Of the aliphatic dibasic acid ester compounds, adipic acid ester compounds or sebacic acid ester compounds are preferably used. Examples of the plasticizer for the adipate ester compound include diisooctyl adipate, diisodecyl adipate, dioctyl adipate, didecyl adipate, and decylisooctyl adipate.
Examples of the plasticizer for the sebacic acid ester compound include dioctyl sebacate, dibutyl sebacate and the like.
[0020]
Among the above plasticizers, at least one of the plasticizers added to the receiving layer is preferably a compound or a condensate containing one or more aryl groups. It is possible to ensure both high color density and light resistance of the printed product.
The blending ratio of the above plasticizer and the receiving layer resin differs depending on the type of plasticizer, the degree of polymerization of the styrene homopolymer, etc., and it is difficult to determine it uniformly, but usually the receiving layer resin: plasticizer The weight ratio is about 5: 5 to 9: 1.
[0021]
In addition, depending on the dye or the like of the thermal transfer sheet used for recording, any resin other than the conventionally known styrenic polymer that can be used as the receiving layer resin is further blended in order to improve the concentration, sharpness, or various storability. Can do. For example, polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, cellulose resin, polysulfone resin, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride resin, polyvinyl acetate resin, Examples include polyvinyl acetal resin, polyvinyl butyral resin, polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer, epoxy resin, and the like.
The blend ratio of these resins is preferably in the range of 5 to 50 parts with respect to 100 parts of the styrene homopolymer. If the amount is less than 5 parts, the effect of modification due to the addition is hardly exhibited. On the other hand, if the amount exceeds 50 parts, the characteristic of the styrenic resin that is excellent in light resistance is impaired.
Thus, when other resins are mixed and used, when transparency is required, such as for OHP applications, it is necessary to select and use a resin with good compatibility.
[0022]
The receiving layer of the thermal transfer image receiving sheet of the present invention preferably contains a fluorosurfactant and / or a silicone resin or a cross-linked product thereof as a release agent.
As the silicone resin, it is more preferable to use epoxy-modified silicone and / or unmodified silicone. In the epoxy-modified silicone, the substituent bonded to the silicon portion of the siloxane moiety of the silicone is any one of an alkylene group, an alkyl group, an aryl group, an ether bond, and an epoxy group.
In the unmodified silicone, the substituent bonded to the silicon portion of the siloxane moiety of the silicone is any one of an alkylene group, an alkyl group, an aryl group, and an ether bond.
The crosslinked silicone product may be a crosslinked product of at least one active hydrogen-containing silicone and an isocyanate compound selected from amino group-containing silicone, carboxyl group-containing silicone, and hydroxyl group-containing silicone, or a crosslinked product of epoxy-modified silicone and amino group-containing compound. Any of a crosslinked product of an amino-modified silicone and an epoxy group-containing compound, a crosslinked product of an amino-modified silicone and an epoxy-modified silicone, and a crosslinked product of a vinyl-modified silicone and a hydrogen-modified silicone may be used.
[0023]
In addition, a release agent other than the above may be used in combination with a conventionally used release agent, and even if a plurality of release agents are used in total, the amount added is 0.1 to the receiving layer resin. 20% by weight is preferred.
In addition to the above, various additives can be added to the receiving layer as necessary. Pigments and fillers such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate and fine powder silica can be added for the purpose of improving the whiteness of the receiving layer and further enhancing the clarity of the transferred image. However, when transparency is required for OHP applications, the amount of pigment or additive added is such that the necessary transparency is not lost.
In addition, a known additive such as a plasticizer, an ultraviolet absorber, a light stabilizer, an antioxidant, a fluorescent whitening agent, and an antistatic agent can be added to the receiving layer as necessary.
[0024]
The resin listed above, the plasticizer and mold release agent listed above, and additives as required are optionally added, and kneaded sufficiently with a solvent, diluent, etc. Manufactured, applied onto the above-mentioned substrate sheet by a forming means such as a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate, dried, and received. Configure the layers.
The intermediate layer, back layer, easy adhesion layer, and antistatic layer, which will be described later, are also applied by the same method as that for forming the receiving layer.
In order to impart antistatic properties, the following antistatic agents can be incorporated into the receiving layer coating solution.
Antistatic agents; fatty acid esters, sulfate esters, phosphate esters, amides, quaternary ammonium salts, betaines, amino acids, acrylic resins, ethylene oxide adducts, and the like.
The addition amount of the antistatic agent is preferably 0.1 to 2.0% by weight with respect to the resin.
[0025]
In the thermal transfer image receiving sheet of the present invention, the coating amount of the receiving layer is 0.5 g / m in terms of dry weight.² ~ 10.0 g / m² It is preferable that The coating amount is 0.5 g / m by dry weight² Less than, for example, when the receiving layer is provided directly on the base sheet, there is a problem that the image of the highlight portion becomes rough because of insufficient adhesion to the thermal head due to the rigidity of the base sheet, etc. There is. This problem can be avoided by providing an intermediate layer that imparts cushioning properties, but is less susceptible to damage to the receiving layer. Further, the roughness of the surface when high energy is applied tends to become relatively worse when the coating amount of the receiving layer is increased, and the coating amount is 10.0 g / m in terms of dry weight.² If it exceeds, for example, the image appears slightly dark in the high density portion during OHP projection.
Hereinafter, unless otherwise specified, the coating amount (or coating amount) of the present invention is a dry weight and a numerical value in terms of solid content.
[0026]
(Middle layer)
In the present invention, an intermediate layer made of various resins may be provided between the base sheet and the receiving layer. Such an intermediate layer is provided with any conventionally known intermediate layer for the purpose of imparting adhesiveness, whiteness, cushioning property, concealing property, antistatic property, anti-curling property, etc. between the base sheet and the receiving layer. Can do.
The binder resin used for the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride. -Vinyl acetate copolymer, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer, polyethylene resin, polypropylene resin, and the like. Among those having active hydrogen, those isocyanate cross-linked products can be used as binders.
[0027]
Moreover, it is preferable to add fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate in order to impart whiteness and concealability.
Furthermore, in order to enhance whiteness, stilbene compounds, benzimidazole compounds, benzoxazole compounds, etc. are added as fluorescent whitening agents, and hindered amine compounds, hindered phenols are used to increase the light fastness of printed materials. In order to add UV-based compounds, benzophenone-based compounds, benzotriazole-based compounds, etc. as ultraviolet absorbers or antioxidants, or to impart antistatic properties, cationic acrylic resins, polyaniline resins, various conductive fillers, etc. Can be added.
[0028]
(Back layer)
Any conventionally known back layer for the purpose of imparting transportability, writing property, antistatic property, antifouling property, anti-curl property, etc. of the thermal transfer image receiving sheet to the surface opposite to the surface provided with the receiving layer of the base sheet. Can be provided.
As the back layer, for example, acrylic resin, cellulose resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl alcohol resin, polyamide resin, polystyrene resin, polyester resin, halogenated polymer, etc. It is possible to use an organic filler such as a silica filler, a polyamide filler, a fluorine filler, or a polyethylene wax, and an inorganic filler such as silicon dioxide or a metal oxide.
As this back layer, it is preferable to use a material obtained by curing the above-described resin with a curing agent. As the curing agent, generally known ones can be used, and among them, an isocyanate compound is preferable. The back layer resin reacts with an isocyanate compound or the like to form a urethane bond and is cured / three-dimensionalized, whereby the heat resistant storage stability and the solvent resistance are improved, and the adhesion to the substrate sheet is improved. As for the addition amount of a hardening | curing agent, 1 thru | or 5 is preferable with respect to the resin 1 reactive group equivalent. If it is less than 1, it takes a long time to complete the curing, and the heat resistance and solvent resistance deteriorate. On the other hand, if the ratio is larger than 5, problems such as a change with time after film formation or a short life of the coating solution for the back surface layer occur.
[0029]
Furthermore, you may add an organic filler or an inorganic filler as an additive in the said back surface layer. The function of these fillers improves the transportability of the thermal transfer image receiving sheet in the printer, and also improves the storage stability of the thermal transfer image receiving sheet, such as preventing blocking.
Examples of the organic filler include acrylic filler, polyamide filler, fluorine filler, and polyethylene wax. Of these, polyamide filler is particularly preferred. Examples of the inorganic filler include silicon dioxide and metal oxide.
The polyamide filler has a molecular weight of 100,000 to 900,000, is spherical, and preferably has an average particle diameter of 0.01 to 30 μm, particularly a molecular weight of 100,000 to 500,000 and an average particle diameter of 0.01 to 10 μm. Is more preferable. As for the type of polyamide-based filler, nylon 12 filler is more preferable than nylon 6 or nylon 66 because it is excellent in water resistance and has no characteristic change due to water absorption.
[0030]
The polyamide filler has a high melting point and is thermally stable, has good oil resistance and chemical resistance, and is difficult to be dyed with a dye. Further, when the molecular weight is 100,000 to 900,000, it hardly wears, has a self-lubricating property, has a low coefficient of friction, and hardly rubs a rubbing partner.
Further, a preferable average particle diameter is 0.1 to 30 μm in the case of the thermal transfer image receiving sheet for reflection image, and 0.01 to 1 μm in the case of the thermal transfer image receiving sheet for transmission image (OHP sheet). If the particle size is too small, the filler is hidden in the back surface layer, and there is a tendency that a sufficient function of slipperiness is not expressed. If the particle size is too large, the protrusion from the back surface layer becomes large. As a result, the coefficient of friction tends to be increased or fillers are lost, which is not preferable.
The blending ratio of the filler to the resin of the back layer is preferably in the range of 0.01% by weight to 200% by weight. In the case of a thermal transfer image receiving sheet for a reflection image, it is more preferably 1% by weight to 100% by weight, and in the case of a thermal transfer image receiving sheet for a transmission image, 0.05% by weight to 2% by weight is more preferable. When the blending ratio of the filler is less than 0.01% by weight, the slipperiness is insufficient, and there is a tendency to cause troubles such as paper jam when the printer is fed. On the other hand, if it exceeds 200% by weight, it is not preferable because it is too slippery and color misalignment or the like tends to occur in the printed image.
[0031]
(Easily adhesive layer)
You may apply | coat and provide the easily bonding layer which consists of adhesive resins, such as acrylic ester resin, a polyurethane resin, and a polyester resin, on the surface and / or back surface of a base material sheet. Further, without providing the coating layer described above, the surface and / or the back surface of the base sheet is subjected to corona discharge treatment or plasma treatment to enhance the adhesion between the base sheet and the layer provided thereon. Can do.
[0032]
(Antistatic layer)
An antistatic layer may be provided on the front surface and / or back surface of the substrate sheet, or on the image receiving surface or back surface of the thermal transfer image receiving sheet or on the outermost surface of both surfaces thereof. Antistatic layer dissolves or disperses antistatic agent, fatty acid ester, sulfate ester, phosphate ester, amides, quaternary ammonium salt, betaines, amino acids, acrylic resin, ethylene oxide adduct, etc. in solvent It is possible to form by applying the applied one.
The coating amount is 0.1 g / m² To 5.0 g / m² It is preferable that However, when provided on the outermost surface, 0.001 g / m² To 0.1 g / m² Is preferred.
As described above, the thermal transfer image-receiving sheet provided with the antistatic layer on the outermost surface has excellent antistatic properties before printing, and therefore can prevent paper feeding defects such as double feed. In addition, troubles such as missing prints caused by dust and the like can be prevented.
[0033]
In the present invention, in the printed matter in which the dye image is formed on the receiving layer of the thermal transfer image receiving sheet described above, a protective layer is preferably transferred and provided on at least a part of the dye image.
Specifically, an image is formed by thermally transferring a sublimation dye from a thermal transfer sheet in which a dye layer is formed on a base material to the receiving layer of the thermal transfer image receiving sheet, and the base material is formed on at least a part of the image. Using a protective layer transfer sheet on which a transferable resin layer (protective layer) is provided, the transferable resin layer is thermally transferred to transfer the protective layer.
As the thermal transfer sheet having the dye layer and the protective layer transfer sheet, conventionally known ones can be used and are not limited. It is also possible to use a thermal transfer sheet in which a dye layer of yellow, magenta, cyan, etc. and a transferable protective layer are provided in the surface order.
[0034]
This also applies to a seal-type thermal transfer image receiving sheet in which a receiving layer is provided on one side of a base sheet and an adhesive layer using a pressure sensitive adhesive or the like and a release paper are provided in order on the other side of the base sheet. The invention can be applied. The means for forming the adhesive layer is also performed in the same manner as the means for forming the receiving layer.
Furthermore, the present invention can also be applied to a receiving layer in a receiving layer transfer sheet in which a dye receiving layer is formed on a substrate so as to be peelable.
First, an image is formed by transferring a sublimation dye from a thermal transfer sheet on which a dye layer is formed on a receiving layer of an intermediate transfer recording medium in which the dye receiving layer is detachably provided on the substrate. The present invention can also be applied to a receptor layer in which the intermediate transfer recording medium is heated to transfer the image-formed receptor layer onto a transfer medium.
[0035]
【Example】
Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. In the text, “part” or “%” is based on weight unless otherwise specified.
Example 1
As a base sheet, a synthetic paper having a thickness of 150 μm (Yupofg # 150, manufactured by Oji Yuka Co., Ltd.) is used, and a white intermediate layer coating solution having the following composition is dried on its one surface by a gravure coating method at 2.0 g. / M²Then, the intermediate layer was formed by coating and drying. Next, on the above intermediate layer, a receiving layer coating solution 1 having the following composition is dried by a gravure coating method at 5.0 g / m.²The coating layer was dried and coated to form a receiving layer, whereby the thermal transfer image receiving sheet of Example 1 was obtained.
[0036]
White interlayer coating solution
25 parts of polyester resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., WR-905)
1 part of water-soluble fluorescent brightener (Ciba Geigy, Uvitex BAC)
75 parts of titanium oxide (manufactured by Tochem Products, TCA-888)
400 parts of water / isopropyl alcohol (weight mixing ratio 1/1)
[0037]
Receiving layer coating solution 1
70 parts of polystyrene resin (weight average molecular weight 100,000)
30 parts of dicyclohexyl phthalate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0038]
(Example 2)
The thermal transfer image-receiving sheet of Example 2 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 2 having the following composition.
Receiving layer coating solution 2
70 parts of polystyrene resin (weight average molecular weight 50,000)
30 parts of diphenyl phthalate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0039]
(Example 3)
The heat transfer image-receiving sheet of Example 3 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 3 having the following composition.
Receiving layer coating solution 3
Polystyrene resin (weight average molecular weight 250,000) 85 parts
Dioctyl phthalate 15 parts
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0040]
Example 4
The thermal transfer image-receiving sheet of Example 4 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 4 having the following composition.
Receiving layer coating solution 4
70 parts of polystyrene resin (weight average molecular weight 250,000)
20 parts of dicyclohexyl phthalate
Dioctyl adipate 10 parts
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0041]
(Example 5)
The thermal transfer image-receiving sheet of Example 5 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 5 having the following composition.
Receiving layer coating solution 5
70 parts of polystyrene resin (weight average molecular weight 250,000)
30 parts of dicyclohexyl phthalate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
Amino-modified silicone 5 parts
(Shin-Etsu Chemical Co., Ltd., X-22-1660-B3)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0042]
(Example 6)
The heat transfer image-receiving sheet of Example 6 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 6 having the following composition.
Receiving layer coating solution 6
70 parts of polystyrene resin (weight average molecular weight 250,000)
30 parts of triphenyl phosphate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0043]
(Example 7)
The heat transfer image-receiving sheet of Example 7 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 7 having the following composition.
Receiving layer coating solution 7
70 parts of polystyrene resin (weight average molecular weight 250,000)
30 parts of triphenyl phosphate
Unmodified silicone 5 parts
(Shin-Etsu Chemical Co., Ltd., X-24-510)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0044]
(Example 8)
The thermal transfer image receiving sheet of Example 8 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 8 having the following composition.
Receiving layer coating solution 8
70 parts of polystyrene resin (weight average molecular weight 250,000)
30 parts of triphenyl phosphate
Unmodified silicone 5 parts
(Shin-Etsu Chemical Co., Ltd., X-24-510)
Hydroxyl-modified silicone 2 parts
(X-62-160AS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Isocyanate compound 1 part
(XDI, Takeda Pharmaceutical Co., Ltd., Takenate A-14)
0.01 parts of dibutyltin dilaurate
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0045]
Example 9
The thermal transfer image-receiving sheet of Example 9 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 9 having the following composition.
Receiving layer coating solution 9
70 parts of polystyrene resin (weight average molecular weight 250,000)
Aromatic condensed phosphate ester 30 parts
(Daihachi Chemical Industry Co., Ltd., CR-733S)
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0046]
(Example 10)
The thermal transfer image-receiving sheet of Example 10 was obtained in the same manner as Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 10 having the following composition.
Receiving layer coating solution 10
70 parts of polystyrene resin (weight average molecular weight 250,000)
Aromatic condensed phosphate ester 30 parts
(Daihachi Chemical Industry Co., Ltd., CR-733S)
Fluorosurfactant (manufactured by 3M, FC431) 5 parts
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0047]
(Comparative Example 1)
The heat transfer image-receiving sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 11 having the following composition.
Receiving layer coating solution 11
100 parts of vinyl chloride-vinyl acetate copolymer
(Electrochemical Industry Co., Ltd., # 1000A)
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
Unmodified silicone 5 parts
(Shin-Etsu Chemical Co., Ltd., X-24-510)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0048]
(Comparative Example 2)
The heat transfer image-receiving sheet of Comparative Example 2 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 12 having the following composition.
Receiving layer coating solution 12
85 parts of polyvinyl butyral resin
(# 3000-1 manufactured by Electrochemical Industry Co., Ltd.)
15 parts of diphenyl phthalate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0049]
(Comparative Example 3)
The receiving layer coating solution was changed to the receiving layer coating solution 13 having the following composition, and the thermal transfer image receiving sheet of Comparative Example 3 was obtained in the same manner as in Example 1.
Receiving layer coating solution 13
70 parts of polycarbonate resin
(Idemitsu Petrochemical Co., Ltd., Taphthalone A2500)
30 parts of diphenyl phthalate
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of chloroform
[0050]
(Comparative Example 4)
The thermal transfer image-receiving sheet of Comparative Example 4 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid was changed to the receiving layer coating liquid 14 having the following composition.
Receiving layer coating solution 14
Polystyrene resin (weight average molecular weight 250,000) 100 parts
5 parts of epoxy-modified silicone
(X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of methyl ethyl ketone / toluene (weight mixing ratio 1/1)
[0051]
The dye-receiving layer of the thermal transfer image-receiving sheet thus obtained and the dye layer of the thermal transfer sheet (thermal transfer sheet CK700L4P for video printer CP-700 manufactured by Mitsubishi Electric Corporation) are overlapped to face each other, and yellow, magenta, cyan For each of these colors, thermal transfer recording was performed from the back surface of the thermal transfer sheet using the thermal head under the following conditions, and then the protective layer was transferred onto the thermal transfer image under the following conditions, and the following various evaluations were performed.
[0052]
(Printing conditions)
Thermal head: KGT-217-12MPL20 (manufactured by Kyocera Corporation)
Heating element average resistance: 3195 (Ω)
Main scanning direction printing density; 300 dpi
Sub-scanning direction print density; 300 dpi
Applied power: 0.12 (w / dot)
1 line cycle: 5 (msec.)
Printing start temperature; 40 (° C)
Gradation control method: Using a multi-pulse test printer capable of varying the number of divided pulses having a pulse length obtained by equally dividing one line period into 256 within a line period, from 0 to 255, the duty of each divided pulse The ratio is fixed at 60%, and the number of pulses per line period is increased by 0 in the 0 step, 17 in the 1 step, 34 in the 2 step, and 34 from 0 to 255 in accordance with the gradation. 16 gradations from 0 step to 15 steps were controlled.
The protective layer was transferred with the number of divided pulses fixed at 255.
[0053]
(Heat resistance before printing)
Prepare two thermal transfer image-receiving sheets for each of Examples and Comparative Examples, store one sheet at room temperature, and store the other sheet in an oven at 60 ° C. for 100 hours. For each thermal transfer image-receiving sheet, Using a sheet, gradations of yellow, magenta, and cyan were printed under the above printing conditions.
About each obtained printed matter, the optical reflection density for each step was measured with an optical densitometer (Macbeth RD-918, manufactured by Macbeth).
For the obtained optical reflection density of each color and each step, the actual value of the optical reflection density of the printed matter of the thermal transfer image-receiving sheet stored at room temperature is [OD].₀And the actual value of the optical reflection density of the printed matter on the thermal transfer image-receiving sheet stored at 60 ° C. for 100 hours [OD].₁For each corresponding color and each step, the change rate of the γ characteristic by the heat resistance test before printing was calculated by the following formula.
[0054]
Rate of change (%) = ([OD]₁-[OD]₀) × 100 / [OD]₀
The rate of change showing the largest value in each color and each step was determined based on the following criteria as indicating the heat resistance before printing of the thermal transfer image-receiving sheet.
○: Change rate is less than 10%, and excellent heat resistance before printing.
Δ: Change rate is 10% or more and less than 20%, and heat resistance before printing is slightly inferior.
X: The rate of change is 20% or more, and the heat resistance before printing is poor.
[0055]
(Light resistance)
The thermal transfer image-receiving sheet of each Example and Comparative Example was subjected to thermal transfer recording with the above-described thermal transfer sheet under the printing conditions described above, and a light fastness test was performed for the cyan color under the following conditions.
Irradiation tester; Atlas Ci135
Light source: xenon lamp
Filter: Inside ... IR filter, Outside ... soda lime glass
Black panel temperature: 45 ° C
Irradiation intensity: 1.2 (w / m²) ... Measured at 420 nm
Irradiation energy: 200 (KJ / m²) ... Integral value at 420 nm
[0056]
For the step where the optical reflection density before irradiation was around 1.0, the change in optical density before and after irradiation was measured, and the residual ratio was calculated by the following formula.
Residual rate (%) = ([optical reflection density after irradiation] / [optical reflection density before irradiation]) × 100
Based on the above residual rate, light resistance was determined according to the following criteria.
○: Residual rate is 80% or more and light resistance is excellent.
Δ: Residual rate is 70% or more and less than 80%, and light resistance is almost satisfactory.
X: The residual ratio is less than 70%, and the light resistance is poor.
[0057]
(Heat-resistant)
The thermal transfer image-receiving sheet of each Example and Comparative Example was subjected to thermal transfer recording with the above-described thermal transfer sheet under the printing conditions described above, and the obtained printed matter was left in an oven at 60 ° C. for 100 hours to spread the image. Was observed with a magnifying glass of 25 times and judged according to the following criteria.
○: No significant change was observed in the image dot size of the printed matter.
(Triangle | delta); Although spreading | diffusion of the dot was recognized, the clear blur was not recognized visually.
X: The dye diffused even in the unprinted part, and clear blur was observed visually.
[0058]
(Print density)
The thermal transfer image-receiving sheet of each Example and Comparative Example was subjected to thermal transfer recording with the thermal transfer sheet under the printing conditions described above, and the optical reflection density of the obtained printed matter was measured. Judgment of evaluation of.
◯: When the printing density of Comparative Example 1 is used as a reference, the optical reflection density is 90% or more near an OD value of 1.
X: When the printing density of Comparative Example 1 is used as a reference, the optical reflection density is less than 90% near an OD value of 1.
[0059]
(Releasability)
The thermal transfer image-receiving sheet of each example and comparative example was subjected to thermal transfer recording with the thermal transfer sheet under the printing conditions described above, and the releasability between the thermal transfer image-receiving sheet and the thermal transfer sheet was determined based on the following criteria.
○: The thermal transfer image receiving sheet and the thermal transfer sheet are easily peeled off, no abnormal transfer or the like occurs, and the releasability is good.
X: The thermal transfer image-receiving sheet and the thermal transfer sheet are fused, abnormal transfer or the like occurs, and the releasability is poor.
[0060]
(Protective layer adhesion)
The thermal transfer image-receiving sheet of each Example and Comparative Example was subjected to thermal transfer recording with the above-described thermal transfer sheet under the above-mentioned printing conditions, and then a protective layer was transferred onto the thermal transfer image under the above-mentioned transfer conditions. A peel test was conducted by attaching a cellophane tape on the protective layer to which the obtained printed matter was transferred and peeling the tape at a peel angle of 180 °, and the protective layer adhesion was determined according to the following criteria.
◯: There is no thing peeled off from the printed matter such as a protective layer on the tape side, and the protective layer adheres sufficiently on the thermal transfer image-receiving sheet, and the protective layer adhesion is good.
X: The protective layer is peeled off from the thermal transfer image receiving sheet by the tape, and the protective layer adhesion is poor.
[0061]
(Evaluation results)
The evaluation results are shown in Table 1 below.
[Table 1]

[0062]
  According to the present invention, as described above, in the thermal transfer image-receiving sheet in which the dye-receiving layer is formed on at least one surface of the base sheet, the receiving layer isPolystyrene resinAnd at least one compound selected from inorganic acid ester compounds and organic acid ester compounds having a molecular weight of 250 to 1000 and / or a plasticizer of a condensate can be used to increase the printing speed of thermal transfer. Thus, a thermal transfer image-receiving sheet having high recording sensitivity, sufficient print density, high image sharpness, various durability and storage stability of the recorded image, and particularly excellent light resistance was obtained. .

Claims (7)

In the thermal transfer image-receiving sheet formed by forming a dye-receiving layer on at least one surface of the base sheet, the receiving layer is selected from polystyrene resin , an inorganic acid ester compound having a molecular weight of 250 to 1000, and an organic acid ester compound. A thermal transfer image-receiving sheet comprising at least one compound and / or a condensate plasticizer.   The thermal transfer image-receiving sheet according to claim 1, wherein the inorganic acid ester compound is a phosphate ester compound.   The thermal transfer image-receiving sheet according to claim 1, wherein the organic acid ester compound is at least one selected from a phthalic acid ester compound and an aliphatic dibasic acid ester compound.   The thermal transfer image-receiving sheet according to claim 3, wherein the aliphatic dibasic acid ester compound is a sebacic acid ester compound or an adipic acid ester compound.   The thermal transfer image-receiving sheet according to any one of claims 1 to 3, wherein at least one of the plasticizers is a compound or condensate containing one or more aryl groups.   The thermal transfer image-receiving sheet according to any one of claims 1 to 5, wherein the receiving layer contains a fluorosurfactant and / or a silicone resin or a cross-linked product thereof as a release agent.   In the printed matter in which the dye image is formed on the receptor layer of the thermal transfer image receptor sheet according to any one of claims 1 to 6, the protective layer is transferred to at least a part of the dye image. Printed product.