JP4061093B2 - Image forming material and image forming method - Google Patents

Description

【０１０１】
式中、Ｒ¹は炭素数１〜１２のアルキル基を表し、Ｒ²〜Ｒ⁴は独立に炭素数１〜１２のアルキレン基を表す。
【０１０２】
以上の中でも、トリメチロールメタン、トリメチロールエタン、トリメチロールプロパン、トリメチロールブタン、トリエチロールメタン、トリエチロールエタン、トリエチロールプロパン、トリエチロールブタン等が好ましく、特に、トリメチロールプロパン（ＴＭＰ）が好ましい。なお、必要に応じて、２種以上の非環式脂肪族多価アルコールを併用することもできる。
【０１０３】
これらの非環式脂肪族多価アルコールを使用することにより、ＰＢＯＰ及びＴＢＰ等の芳香族ヒドロキシ化合物と比較して、彩度を格段に向上することができる。
【０１０４】
なお、非環式脂肪族多価アルコールの画像形成層に占める割合は、性能のバランスを考慮して決定され、１質量％以上が好ましく、２質量％以上がさらに好ましく、３．５質量％以上がより好ましく、一方、３５質量％以下が好ましく、３０質量％以下がより好ましく、２５質量％以下が更に好ましい。
【０１０５】
（画像形成材の構造）
図１には、画像形成層が多層の場合として、３原色に対応して３層の画像形成層２１１〜２１３が支持体２１０上に積層されている画像形成材の具体例を示した。各画像形成層は、発色前駆体２２１を内包する第１熱応答性マイクロカプセル２２２を保持している。また、各画像形成層は、異なる色に対応する顕色剤２１４〜２１６を内包する第２熱応答性マイクロカプセル２１７〜２１９を、それぞれ含有している。
【０１０６】
支持体としては、中性紙、酸性紙、コーティツドペーパー、ラミネート紙などの紙類；ポリエチレンテレフタレートフイルム、３酢酸セルロースフイルム、ポリエチレンフイルム、ポリスチレンフイルム、ポリカーボネートフイルム等のフイルム類；アルミニウム、亜鉛、銅などの金属板；これらの支持体表面に表面処理、下塗、金属蒸着処理などの各種処理を施したもの等を使用できる。
【０１０７】
光硬化剤２２０は光硬化主剤および光硬化開始剤を含んでおり、第２熱応答性マイクロカプセルに内包されている。そして、支持体側から、シアン（Ｃ）発色用の顕色剤２１４を内包する第２熱応答性マイクロカプセル２１７を有する画像形成層２１１と、マゼンタ（Ｍ）発色用の顕色剤２１５を内包する第２熱応答性マイクロカプセル２１８を有する画像形成層２１２と、イエロー（Ｙ）発色用の顕色剤２１６を内包する第２熱応答性マイクロカプセル２１９を有する画像形成層２１３とが積層されている。
【０１０８】
なお、色に関する積層の順番は、各色の濃さ等を考慮して決定され、例えば支持体側から、シアン（Ｃ）、マゼンタ（Ｍ）、イエロー（Ｙ）の順とする。
【０１０９】
熱応答性マイクロカプセルは、バインダー２２４中に保持されている。また、バインダー中で熱応答性マイクロカプセルの外側には、非環式脂肪族多価アルコール２２３としてＴＭＰが分散されている。なお、バインダーとしては、ポリビニルアルコール、澱粉、ゼラチン、アラビアゴム等を使用できる。
【０１１０】
以上の様な画像形成層は、次の様にして製造できる。先ず、第１熱応答性マイクロカプセル及び第２熱応答性マイクロカプセルを、それぞれ調製し、水系エマルジョンを得る。得られた水系エマルジョンを混合し、これにＴＭＰ及びバインダーを添加して画像形成層原料を調製する。得られた画像形成層原料は、ブレードコーター、ロッドコーター、ナイフコーター、ロールドクターコーター、リバースロールコーター、トランスファーロールコーター、グラビアコーター、キスロールコーター、カーテンコーター、エクストルージョンコーター等を利用して塗布され、１０〜６０℃で例えば送風乾燥して水分を除去することにより、画像形成層が得られる。
【０１１１】
なお、画像形成層には、必要に応じて、塩基、分光増感剤などを更に添加することもできる。
【０１１２】
各画像形成層の厚さは、マイクロカプセルの粒子径を十分小さくすることによって、薄膜とできるため、十分な解像度および発色感度を実現できる。具体的には、１５０μｍ以下が好ましく、１００μｍ以下がより好ましく、５０μｍ以下が更に好ましく、３０μｍ以下が最も好ましい。一方、十分な発色強度を確保する観点から、２μｍ以上が好ましく、５μｍ以上がより好ましく、８μｍ以上が更に好ましい。
【０１１３】
また、同様の理由から、３層の画像形成層と層間保護層との全体の層厚は、１０μｍ以上が好ましく、２０μｍ以上がより好ましく、３０μｍ以上が更に好ましく、一方、３００μｍ以下が好ましく、２００μｍ以下がより好ましく、１００μｍ以下が更に好ましい。
【０１１４】
各画像形成層の間には、酢ビ・塩ビからなる層間保護層２２５及び２２６が形成されている。
【０１１５】
また最表層には必要に応じて、ポリビニルアルコール、スチレンブタジエンゴム、ゼラチン等からなり、厚み１〜５μｍの表面保護層２２７等を積層することもできる。
【０１１６】
画像形成層が複数積層されている場合、単層と比べ、得られる画像の品位は良好である。
【０１１７】
（画像の形成方法）
以上の様にして作製された画像形成材上には、感光感熱方式によりフルカラー画像を形成することができる。
【０１１８】
先ず、色の違いに対応する光を画像形成材に照射し、光硬化剤を硬化してネガ型潜像を形成する。潜像を作製するための露光は、１回の工程で行う場合もあれば２回以上の工程で行うこともあり、画像形成材の構造、得られる画像品位および作業性などを考慮して決定される。
【０１１９】
次に、潜像が形成された画像形成材を、所定の温度に加熱する。加熱により、熱応答性マイクロカプセルに内包される発色前駆体および顕色剤が熱応答性透過膜壁を通過して、熱応答性マイクロカプセル外部に拡散する。このため、発色前駆体および顕色剤が接触し反応することにより、発色する。この結果、潜像が現像される。
【０１２０】
現像のための加熱工程も、１回の工程で行う場合もあれば２回以上の工程で行うこともあり、画像形成材の構造、得られる画像品位および作業性などを考慮して決定される。例えば、画像形成層が３層形成されており、各層の画像形成層に含まれる第２熱応答性マイクロカプセルの壁を構成する熱応答性透過膜のガラス転移温度が異なる場合は、異なる温度で加熱を３回行い、各色で現像を行う。また、露光により光硬化剤が硬化されている場合は、１回の加熱により現像を行えるため好ましい。更に、現像後は、必要に応じて更に露光および加熱などを行い、画像の定着を行う場合もある。
【０１２１】
以上の様に、画像形成層に光硬化剤を存在させておき、露光により非発色領域を硬化してネガ型潜像を形成し、加熱により現像する感光感熱方式に依れば、少量の熱エネルギーにより十分な解像度の画像が得られる。
【０１２２】
本発明の画像形成材は、複写機およびプリンター等の画像形成装置に好適に使用され、特にフルカラーの画像形成に好適である。
【０１２３】
【実施例】
以下、実施例および比較例により本発明を具体的に説明するが、本発明は以下の実施例に制限されるものではない。なお、特に明記しない限り、試薬等は市販の高純度品を使用した。
【０１２４】
（解像度）
解像度は、ＤＰＩとカラーバランスとを考慮して、良好（○）、実用に耐え得る程度（△）、不良（×）の３段階で評価した。
【０１２５】
（発色感度）
画像形成材を所定の温度で３０秒〜１分間保温し、発色の状態を確認し、十分な感度がある（○）、実用に耐え得る程度の感度である（△）、感度が不足している（×）の３段階で評価した。
【０１２６】
（彩度）
カプセル等が存在せず発色前駆体および顕色剤のみが存在する状態で、発色前駆体および顕色剤が反応した際に得られる画像が最も鮮やかであるとし、実際の画像形成材により得られた画像の彩度を、極めて鮮やかである（○）、鮮やかである（△）、くすんでいる（×）の３段階で評価した。
【０１２７】
（混色）
標準画像と、標準画像をシアン（Ｃ）、マゼンタ（Ｍ）及びイエロー（Ｙ）に色分解した画像をそれぞれ形成し、標準画像と色分解された画像とを比較することにより、混色の程度を、混色が確認されない（○）、僅かに混色が確認される（△）、混色が確認される（×）の３段階で評価した。
【０１２８】
（実施例１）画像形成材１
発色前駆体として９質量部の大東ケミックス社製ジアゾニウム塩（商品名：ＤＨ−３００ＰＦ₆）を、溶媒として１７１質量部のＤＢＰに４０℃で溶解し、イソシアネートモノマー（三井武田ケミカル（株）製、商品名：タケネートＤ１１０Ｎ）１６０質量部を混合した。これに、２７９質量部の水と乳化剤として２１質量部のクラレ社製ポリビニルアルコール（商品名：ＰＶＡ１１７）とを添加し、ホモジナイザーにより乳化後、４０℃で２０時間反応して、平均粒子径１μｍの第１熱応答性マイクロカプセルを得た。これをイオン交換樹脂（オルガノ社製、商品名：アンバーライトＭＢ−３）を用いて精製し、５０質量％の第１熱応答性マイクロカプセルを含む水系エマルジョン６００質量部を調製した。
【０１２９】
一方、シアン（Ｃ）用の顕色剤として２質量部の２−Ｈｙｄｒｏｘｙ−３−ｎａｐｈｔｈａｌｅｎｅ−３−ｃａｒｂｏｘｙｌｉｃ ａｃｉｄ ｍｏｒｐｈｏｌｉｎｏｐｒｏｐｙｌａｍｉｄｅを、低極性液液媒体として２５℃での動粘度が１５ｍｍ²／秒の流動パラフィン１８質量部の存在下、ビーズミルにより平均粒子径が０．５μｍとなるまで粉砕した。その後、得られたスラリーを８質量部の光硬化主剤であるポリエステルアクリレート（粘度：６，０００〜１２，０００Ｐａ・ｓ）と混合して、顕色剤を光硬化主剤に移送した。また、別に光硬化開始剤として１，１’−ジ−ｎ−ヘプチル−３，３，３’，３’−テトラメチルインドジカルボシアニン−トリフェニル−ｎ−ブチルボレートを１質量％溶解した光硬化主剤のポリエステルアクリレート（粘度：６，０００〜１２，０００Ｐａ・ｓ）１９０質量部を用意し、顕色剤を含む硬化主剤と混合した。得られた混合物に、イソシアネート、水および乳化剤を第１熱応答マイクロカプセルの場合と同様に添加および反応することにより、平均粒子径が２μｍの第２熱応答性マイクロカプセルを得た。これを用いて、５０質量％の第２熱応答性マイクロカプセルを含む水系エマルジョン６００質量部を調製した。
【０１３０】
なお、得られた第２熱応答性マイクロカプセルの電子顕微鏡写真を図２に示す。第２熱応答性マイクロカプセルが実際に形成されていることが分かる。
【０１３１】
更に同様にして、顕色剤がマゼンタ（Ｍ）用の４−ヒドロキシ−１−メチル−２−キノロンであり、光硬化開始剤がマゼンタ（Ｍ）用の１，１’−ジ−ｎ−ヘプチル−３，３，３’，３’−テトラメチルインドカルボシアニントリフェニル−ｎ−ブチルボレートである第２熱応答性マイクロカプセルを作製した。
【０１３２】
また、顕色剤がイエロー（Ｙ）用の２，４−ジメトキシアセトアセトアニリドであり、光硬化開始剤がイエロー（Ｙ）用の３，３−ジメチル−１−ヘプチルインド−３’−ヘプチルチアシアニン−トリフェニル−ｎ−ブチルボレートである第２熱応答性マイクロカプセルを作製した。
【０１３３】
次に、第１熱応答性マイクロカプセルを含む水系エマルジョン１０質量部と、シアン（Ｃ）用の第２熱応答性マイクロカプセルを含む水系エマルジョン１０質量部と、１質量部のＴＭＰと、重量平均分子量１，７００のポリビニルアルコール１質量部とを混合し、シアン（Ｃ）用の画像形成層原料を調製した。これを、厚み２００μｍのコート紙よりなる支持材上に塗布し４０℃で乾燥して、厚み３０μｍのシアン（Ｃ）用画像形成層を作製した。
【０１３４】
更に、得られたシアン（Ｃ）用の画像形成層上に、酢ビ・塩ビ共重合体を５０質量％含有するサスペンジョン（日信化学社製、商品名：ビニブラン３８０）を塗布し４０℃で乾燥した。これを５０℃で溶融することにより、厚み１０μｍの層間保護層を形成した。
【０１３５】
引続き、シアン（Ｃ）用の画像形成層の場合と同様にして、マゼンタ（Ｍ）用の画像形成層を形成後、層間保護層を作製し、更に、イエロー（Ｙ）用の画像形成層を形成した。そして、厚み２μｍのポリビニルアルコールからなる表面保護層を積層し、画像形形成材１を得た。
【０１３６】
得られた画像形成材１の性能を、現像温度９０℃及び現像時間２０秒の条件で評価したところ、解像度：○、発色感度：○、彩度：○、混色：○であった。
【０１３７】
（比較例１）画像形成材２
ポリビニルアルコールからなる層間保護層をキャスト法に成膜した以外は、画像形成材１の場合と同様にして、画像形成材２を作製した。
【０１３８】
得られた画像形成材２の性能を、現像温度９０℃及び現像時間２０秒の条件で評価したところ、解像度：×、発色感度：△、彩度：×、混色：×であった。
【０１３９】
（比較例２）画像形成材３
スチレン・ブタジエンゴム（ＳＢＲ）からなる層間保護層をキャスト法に成膜した以外は、画像形成材１の場合と同様にして、画像形成材２を作製した。
【０１４０】
得られた画像形成材３の性能を、現像温度９０℃及び現像時間２０秒の条件で評価したところ、解像度：×、発色感度：△、彩度：×、混色：×であった。
【０１４１】
【発明の効果】
画像形成層の間に、熱応答性透過膜壁のガラス転移温度より低温で溶融法により成膜された層間保護層を形成することにより、高い解像度、発色感度および彩度を実現でき、混色を抑制できる。
【図面の簡単な説明】
【図１】画像形成材の構造を説明するたの模式的断面図である。
【図２】第２熱応答性マイクロカプセルの電子顕微鏡写真である。
【符号の説明】
２１０ 支持体
２１４ 顕色剤
２１５ 顕色剤
２１６ 顕色剤
２１７ 第２熱応答性マイクロカプセル
２１８ 第２熱応答性マイクロカプセル
２１９ 第２熱応答性マイクロカプセル
２２０ 光硬化剤
２２１ 発色前駆体
２２２ 第１熱応答性マイクロカプセル
２２３ 非環式脂肪族多価アルコール
２２４ バインダー
２２５ 層間保護層
２２６ 層間保護層
２２７ 表面保護層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming material and an image forming method suitable for an image forming apparatus such as a copying machine and a printer, and more particularly to an image forming material and a method suitable for full color.
[0002]
[Prior art]
As a method for forming a color image, a silver salt photographic method, a heat sensitive method, an electrophotographic method, an ink jet method, and the like have been put into practical use, but these methods require consumables. Specifically, the silver salt photographic method requires a developer, the thermal method requires an ink ribbon, the electrophotographic method requires a color toner, and the inkjet method requires a color ink. These consumables become waste after use. From this point of view, self-coloring image forming materials have been developed for the purpose of reducing waste without requiring consumables.
[0003]
For example, Japanese Patent No. 2627830 discloses a photosensitive pressure-sensitive method in which an image forming material is exposed to form a latent image, and pressurized to develop a color image.
[0004]
However, in the case of the photosensitive pressure-sensitive method, sufficient resolution may not be obtained because the microcapsules are broken by pressurization and the color precursor and the developing material are reacted to cause color development.
[0005]
Further, a method for developing by heating is described in JP-A-60-242093, which is called TA method and put into practical use.
[0006]
However, in the case of the heat-sensitive method, the coloring component passes through the microcapsule wall and reacts by heating at a temperature higher than the glass transition temperature of the microcapsule wall, so that a large amount of heat energy is required for color development or sufficient resolution is obtained. It may not be possible.
[0007]
As a means for avoiding the above-described problems, for example, a photosensitive heat sensitive system has been proposed. In the case of the photothermographic method, a photocuring agent is present in the image forming layer, a non-colored area is cured by exposure to form a negative latent image, and development is performed by heating. In the case of this method, it is considered that an image with sufficient resolution can be obtained with a small amount of heat energy.
[0008]
[Problems to be solved by the invention]
As the photosensitive and thermosensitive method, for example, a photosensitive and thermosensitive recording layer in which a color developing component is encapsulated in a thermoresponsive microcapsule and a photopolymerizable developer is disposed outside the thermoresponsive microcapsule is disclosed in JP-A-2000-199952. And a photopolymerizable developer is applied with an emulsion and dried.
[0009]
However, in the case of such a method, there is a possibility that an image forming material having a desired performance cannot be obtained due to application of an emulsion.
[0010]
In addition, as another photosensitive heat-sensitive method, for example, JP-A 2000-218944 and JP-A 2000-296675 have proposed a method in which a diazonium salt and a coupler are encapsulated in multiple heat-responsive capsules. Japanese Patent Application Laid-Open Nos. 2000-221692 and 2001-83697 propose a method in which multiple capsules are made light-responsive and have photosensitivity and heat sensitivity.
[0011]
However, in these systems, if the amount of diazonium salt necessary to achieve sufficient color development is to be ensured, the capsule particle size increases because of the multiple capsules, and the resolution may be insufficient. . Also, since the particle size cannot be made sufficiently small, the image forming layer cannot be made sufficiently thin, and when the amount of diazonium salt is increased and the capsule particle size is increased, the layer thickness of the image forming layer is increased. On the contrary, the color development sensitivity may be lowered. Furthermore, in the method of forming a negative latent image by light irradiation, a photocuring agent is used, so that the particle diameter of the multiple capsules may be further increased. The photo-curing agent may be required, and sufficient resolution and color development sensitivity may not be realized. In addition, these defects may be particularly noticeable when a plurality of image forming layers are laminated.
[0012]
In addition, it may be difficult to produce the capsule itself, and a capsule having desired characteristics may not be manufactured. One reason for this is that it is difficult to produce a capsule containing a sufficiently finely-developed developer. Even if the developer can be sufficiently finely powdered using an aqueous low-viscosity grinding medium, moisture may not be sufficiently removed. Furthermore, a sufficient amount of developer may not be included.
[0013]
On the other hand, in various formats including the above-described methods, attempts have been made to improve the color development sensitivity by other methods. For example, JP-A-61-277490 describes that an aromatic hydroxy compound has an effect of lowering the glass transition temperature of the microcapsule wall, and uses the aromatic hydroxy compound as a sensitizer. It has been proposed. In addition, p-benzyloxyphenol (PBOP), pt-butylphenol (TBP) and the like have been put into practical use.
[0014]
However, even when these aromatic hydroxy compounds are used, the color development sensitivity may not be sufficiently improved, and in particular, the saturation may be insufficient.
[0015]
As another method for improving resolution and color development sensitivity, there is a method of laminating a plurality of relatively thin image forming layers, and this method is described in various publications including the above-mentioned publications. It has also been put into practical use. In this case, image forming layers each containing a precursor that develops yellow (Y), magenta (M), and cyan (C) are usually laminated, and an interlayer protective layer is formed between the layers.
[0016]
However, when a plurality of image forming layers are laminated, although the interlayer protective layer is formed between the layers, depending on the components contained in the image forming layer, the barrier property of the interlayer protective layer is not good. For this reason, the components of a certain image forming layer may pass through the interlayer protective layer and enter another image forming layer. Even in the case of an interlayer protective layer having sufficient barrier properties, if the film forming temperature is too high, the color forming precursor and the developer may react to form color when forming the interlayer protective layer. For these reasons, sufficient resolution and color development sensitivity may not be realized or color mixing may occur.
[0017]
In view of the circumstances as described above, an object of the present invention is to realize an image forming material that can realize sufficient resolution, color development sensitivity, and saturation, and color mixing is suppressed.
[0018]
[Means for Solving the Problems]
According to the present invention for achieving the above object, two or more image forming layers containing a color former and a developer are laminated on a support, and a film is formed between the image forming layers by a melting method. Made of vinyl chloride resin An image forming material characterized in that an interlayer protective layer is formed is provided.
[0019]
In addition, the image formation includes a first heat-responsive microcapsule comprising a thermoresponsive permeable membrane wall and encapsulating a coloring precursor, and a second thermoresponsive microcapsule comprising a thermoresponsive permeable membrane wall and encapsulating a developer. Two or more layers are laminated on a support, and a film is formed between the image forming layers by a melting method at a temperature lower than the glass transition temperature of the heat-responsive permeable membrane wall. Made of vinyl chloride resin An image forming material characterized in that an interlayer protective layer is formed is provided.
[0020]
In addition, a process of irradiating such an image forming material with light and curing the photocuring agent to form a latent image;
The image forming material on which the latent image is formed is heated, and at least one of the color precursor and the developer is passed through the thermally responsive permeable membrane wall, and the color precursor, the developer, And developing the latent image by causing the color-forming precursor to develop color,
An image forming method is provided.
[0021]
Two or more sufficiently thin image forming layers are laminated on the image forming material, and each layer contains second thermoresponsive microcapsules containing different developers. In the case of such a laminated structure, for example, a layer that develops cyan (C), a layer that develops magenta (M), and a layer that develops yellow (Y) are laminated from the support side.
[0022]
In the case where a plurality of image forming layers are laminated, it is preferable to form an interlayer protective layer having a sufficient barrier property between each layer so that mixing of components does not occur between each layer, and the substance contained in the image forming layer In some cases, particularly high barrier properties are required.
[0023]
When a sensitizer such as an acyclic aliphatic polyhydric alcohol is used as such a substance, the acyclic aliphatic polyhydric alcohol acts not only on the thermoresponsive microcapsule wall but also on the interlayer protective layer. Therefore, a particularly high barrier property is required for the interlayer protective layer.
[0024]
From this point of view, an interlayer protective layer formed by a melting method is formed. The interlayer protective layer formed by the melting method is considered to have a high barrier property with less voids compared to a cast film or the like produced by volatilizing the solvent.
[0025]
The interlayer protective layer is preferably formed by a melting method at a temperature lower than the glass transition temperature of the thermoresponsive microcapsule wall. If the interlayer protective layer can be formed at a low temperature, the coloring precursor and the developer are mixed through the thermally responsive microcapsule wall and reacted to develop a color during film formation. From this viewpoint, the deposition temperature of the interlayer protective layer is preferably 60 ° C. or less, more preferably 55 ° C. or less, and further preferably 50 ° C. or less. On the other hand, in order to obtain an interlayer protective layer having sufficient barrier properties, 10 ° C. or higher is preferable, 20 ° C. or higher is more preferable, and 30 ° C. or higher is still more preferable.
[0026]
For the reasons described above, by disposing an interlayer protective layer formed by the melting method between the image forming layers, high resolution, color development sensitivity and saturation can be realized, and color mixing can be suppressed.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[0028]
(Interlayer protective layer)
As a method for producing an interlayer protective film, first, a suspension containing a raw material resin for an interlayer protective layer is applied, dried at 10 to 60 ° C. to form a coated layer, and the obtained coated layer is coated with a heat-responsive permeable membrane wall. A method of melting at a temperature lower than the glass transition temperature to form a film is preferred. By using the suspension, an interlayer protective layer having a high barrier property can be formed. Further, from the viewpoint of forming an interlayer protective layer having higher barrier properties with good productivity, the average particle diameter of the raw material resin in the suspension is preferably 0.05 μm or more, more preferably 0.1 μm or more, while 10 μm The following is preferable, and 5 μm or less is more preferable.
[0029]
Moreover, as a manufacturing method of an interlayer protective film, first, a paste resin containing a raw material resin for an interlayer protective layer is applied, dried at 10 to 60 ° C. to form a coated layer, and the obtained coated layer is thermally responsively transmitted. A method in which the film is melted at a temperature lower than the glass transition temperature of the film wall to form a film is preferable. By using a paste resin, an interlayer protective layer having a high barrier property can be formed. In addition, from the viewpoint of forming an interlayer protective layer having higher barrier properties with good productivity, the average particle size of the raw material resin in the paste resin is preferably 0.05 μm or more, more preferably 0.1 μm or more, 10 micrometers or less are preferable and 5 micrometers or less are more preferable.
[0030]
The suspension and paste resin matrix is preferably aqueous.
[0031]
Furthermore, if necessary, suspensions and paste resins containing plasticizers, stabilizers, viscosity reducing agents, diluents, organosols and the like can also be used.
[0032]
The raw material resin is preferably a vinyl chloride resin, an acrylic resin, or a styrene resin from the viewpoints of film formability and sufficient barrier properties of the resulting interlayer protective layer, and among them, a vinyl chloride resin is preferable.
[0033]
Examples of the vinyl chloride resin include polyvinyl chloride, a copolymer of vinyl acetate and vinyl chloride, a copolymer of vinylidene chloride and vinyl chloride, a copolymer of acrylonitrile and vinyl chloride, and (meth) acrylic acid. Copolymer of ester and vinyl chloride, copolymer of styrene and vinyl chloride, copolymer of vinyl ether and vinyl chloride, copolymer of maleic acid and maleic ester and vinyl chloride, aliphatic vinyl and chloride A copolymer of vinyl, a copolymer of ethylene and vinyl chloride, a copolymer of propylene and vinyl chloride, or the like can be used, and a third monomer can also be copolymerized.
[0034]
Among these, a copolymer of vinyl acetate and vinyl chloride (vinyl acetate / vinyl chloride) is preferable. In the case of copolymerization, the content of the monomer copolymerized with vinyl chloride is preferably 40 mol% or less, and more preferably 30 mol% or less.
[0035]
Examples of the acrylic resin include poly (meth) acrylic acid ester, a copolymer of vinyl acetate and (meth) acrylic acid ester, a copolymer of vinylidene chloride and (meth) acrylic acid ester, acrylonitrile and (meta ) A copolymer of acrylic acid ester, a copolymer of vinyl chloride and (meth) acrylic acid ester, a copolymer of styrene and (meth) acrylic acid ester, a copolymer of vinyl ether and (meth) acrylic acid ester Polymer, Copolymer of maleic acid and maleic acid ester with (meth) acrylic acid ester, Copolymer of aliphatic vinyl with (meth) acrylic acid ester, Copolymerization of ethylene with (meth) acrylic acid ester Copolymers, copolymers of propylene and (meth) acrylic acid esters can be used, and a third monomer is copolymerized. And it can also be.
[0036]
Among these, a copolymer of vinyl acetate and (meth) acrylic acid ester is preferable. In the case of copolymerization, the content of the monomer copolymerized with the (meth) acrylic acid ester is preferably 40 mol% or less, and more preferably 30 mol% or less.
[0037]
Examples of the styrene resin include polystyrene, a copolymer of vinyl acetate and styrene, a copolymer of vinylidene chloride and styrene, a copolymer of acrylonitrile and styrene, and a copolymer of (meth) acrylic acid ester and styrene. , Copolymer of vinyl chloride and styrene, copolymer of vinyl ether and styrene, copolymer of maleic acid and maleate ester and styrene, copolymer of aliphatic vinyl and styrene, ethylene and styrene A copolymer, a copolymer of propylene and styrene, and the like can be used. As the styrene, a styrene derivative such as an α-substituted product can be used, and a third monomer can be copolymerized.
[0038]
Among these, a copolymer of vinyl acetate and styrene is preferable. In the case of copolymerization, the content of the monomer copolymerized with styrene is preferably 40 mol% or less, and more preferably 30 mol% or less.
[0039]
In order to obtain a sufficient barrier property, the thickness of the interlayer protective layer produced as described above is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more, while high resolution, color development sensitivity and In order to maintain the saturation, it is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less.
[0040]
(Form of thermoresponsive microcapsule)
As the form of the thermoresponsive microcapsule, the wall of the thermoresponsive microcapsule is made of a thermoresponsive permeable membrane wall, and the coloring precursor and the developer are the first thermoresponsive microcapsule and the second thermoresponsive, respectively. It is preferable that the microcapsules are individually encapsulated.
[0041]
By adopting such a form, the thermoresponsive microcapsule can be made into a single layer (single microcapsule), so that a sufficient amount of color precursor and developer are required to realize sufficient color development. The particle size of the thermoresponsive microcapsule can be made sufficiently small. In addition, since the particle size of the thermoresponsive microcapsules can be made sufficiently small, the image forming layer can be made thin while securing a sufficient amount of the color precursor and developer. Furthermore, since a single thermoresponsive microcapsule is used, the amount of photocuring agent used can be reduced, and the heat-responsive microcapsule can have a small particle size. As a result, high resolution, color development sensitivity and saturation can be realized.
[0042]
(First thermoresponsive microcapsule)
The average particle size of the first thermoresponsive microcapsules encapsulating the coloring precursor is preferably 0.1 μm or more, more preferably 0.3 μm or more, and more preferably 0.5 μm or more in order to ensure a sufficient amount of the coloring precursor. Is more preferable. On the other hand, from the viewpoint of resolution and color development sensitivity, it is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.
[0043]
In addition, as an average particle diameter, a volume average particle diameter can be measured, for example using Coulter Electronics (UK) coulter multi-cider.
[0044]
The color developing precursor means a color developing by causing a coupling reaction and oxidation-reduction reaction (electron accepting reaction) with a developer, and a diazonium precursor, a leuco precursor, or the like can be used.
[0045]
Examples of the diazonium-based precursor include 4- (4′-methylphenylthio) -2,5-diethoxybenzenediazonium salt, 4-pyrrolidino-3-methylbenzenediazonium salt, 4-morpholino-2,5-di Butoxybenzenediazonium salt, 4-morpholinobenzenediazonium salt, 4-morpholino-2,5-octoxybenzenediazonium salt, 4- (N- (2-ethylhexanoyl) piperazino) -2,5 diethoxybenzenediazonium salt 4-N, N-diethylaminobenzenediazonium salt, 3-(-2-octyloxyethoxy) -morpholinobenzenediazonium salt, 4-N-hexyl-N-tolylamino-2-hexyloxybenzenediazonium salt, etc. can be used. As a salt, hexafluorophosphate DOO, tetrafluoroborate, 1,5-naphthalene sulfonate, perfluoroalkyl carbonates, perfluoroalkyl sulfonate, zinc chloride salt, and the like tin chloride salts.
[0046]
Further, as the leuco precursor, a triarylmethane precursor, a diphenylmethane precursor, a thiazine precursor, a xanthene precursor, a spiropyran precursor, and the like can be used, and more specifically, 3,3- Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylamino) phthalide, 3- (p-dimethylaminophenyl) -3- (1,3-dimethylindole-3 -Yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (o-methyl-p-dimethylaminophenyl) -3- (2-methylindole) -3-yl), 4,4'-bis (dimethylamino) benzhydrin benzyl ether, N-halophenylleucooramine, rhodamine-B- Nilinolactam, Rhodamine-B- (p-chloroanilino) lactam, 2-benzylamino-6-diethylaminofluorane, 2-anilino-6-diethylaminofluorane, 2-anilino-3-methyl-6-cyclohexylmethylaminofluorane, 2-anilino-3-methyl-6-isoamylethylaminofluorane, 2- (o-chloroanilino) -6-diethylaminofluorane, 2-octylamino-6-diethylaminofluorane, 2-ethoxyethylamino-3-chloro 2-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, benzoylleucomethylene blue, p-nitrobenzylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran 3,3'-dichloro-over scan pillow Gina shift pyran, 3-benzyl pyro Gina shift pyran, 3-propyl - spiro - dibenzo pyran or the like can be used.
[0047]
The proportion of the coloring precursor in the first thermoresponsive microcapsule is 0.5% by mass or more from the viewpoint of reducing the particle diameter of the first thermoresponsive microcapsule while securing a sufficient amount of the coloring precursor. Preferably, 1 mass% or more is more preferable, and 2 mass% or more is still more preferable. On the other hand, the upper limit of the color precursor content is not particularly limited, but is usually 99% by mass or less because there is a thermoresponsive microcapsule wall. Further, when the color forming precursor is at a high concentration, it may contain an insoluble part or may be solid. Including such a case, the content of the color forming precursor is 60% by mass or less, 30% by mass or less, 10% by mass or less, and the like.
[0048]
(Second thermoresponsive microcapsule)
The average particle size of the second thermoresponsive microcapsules encapsulating the developer is preferably 0.1 μm or more, more preferably 0.3 μm or more, and more preferably 0.5 μm or more in order to ensure a sufficient amount of the developer. Is more preferable. On the other hand, from the viewpoint of resolution and color development sensitivity, it is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.
[0049]
The color developer is a substance that causes the color precursor to develop color by causing a coupling reaction and oxidation-reduction reaction (electron accepting reaction) with the color precursor, and the most suitable color precursor to be used is selected. Is done.
[0050]
For example, clay materials such as acid clay, activated clay, attabargite and zeolite; aromatic carboxylic acids such as benzoic acid, salicylic acid and 3,5-di- (α-methylbenzyl) salicylic acid; zinc salt of aromatic carboxylic acid, aluminum Polyvalent metal salts such as salts and magnesium salts; phenol resins such as phenol formaldehyde resins and phenol acetylene resins; polyvalent metal salts of phenol resins and the like can be used.
[0051]
More specifically, clay color developer, resorcin color developer, phloroglucin color developer, pyrazolone color developer, diketone color developer, oxydiphenyl color developer, naphthol color developer, phenol -Based color developer, phenol resin color developer, bisphenol color developer, salicylic acid color developer, hydroxybenzoate color developer, etc., for example, resorcin, phloroglucin, 2,3-dihydroxynaphthalene- 6-sulfonic acid sodium, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxy-6-sulfonylnaphthalene, 2-hydroxy-3-naphtho Acid anilide, 2-hydroxy-3-naphthoic acid ethanolamide, 2-hydroxy 3-naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid-N-dodecyloxypropylamide, 2-hydroxy-3 mononaphthoic acid tetradecylamide, acetanilide, acetoacetanilide, benzoylacetanilide, 2-chloro-5-octyl Acetoacetanilide, 1-phenyl-3-methyl-5-virazolone, 1- (2′-octylphenyl) -3-methyl-5-pyrazolone, 1- (2 ′, 4 ′, 6′-trichlorophenyl) -3 -Pensuamido-5-virazolone, 1- (2 ', 4', 6'-trichlorophenyl) -3-anilino-5-virazolone, 1-phenyl-3-phenylacetamido-5-virazolone, 1- (2- Dodecyloxyphenyl) -2-methyl carbonate cyclohexane-3,5-dione, 1- 2-dodecyloxyphenyl) cyclohexane-3,5-dione, N-phenyl-N-dodecylbarbituric acid, N-phenyl-N- (3-stearyloxy) butylbarbituric acid, 2,2-bis (p- Hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) pentane, 2,2-bis (p-hydroxyphenyl) ethane, 2,2-bis (p-hydroxyphenyl) butane, 2,2-bis ( 4'-hydroxy-3 ', 5'-dichlorophenyl) propane, 1,1- (p-hydroxyphenyl) cyclohexane, 1,1- (p-hydroxyphenyl) propane, 1,1- (p-hydroxyphenyl) pentane 1,1- (p-hydroxyphenyl) -2-ethylhexane, 3,5-di (α-methylbenzyl) salicylic acid and Its polyvalent metal salt, 3,5-di (tert-butyl) salicylic acid and its polyvalent metal salt, 3-α, α-dimethylbenzylsalicylic acid and its polyvalent metal salt, p-hydroxybenzoic acid butyl, p-hydroxy Benzyl benzoate, p-hydroxybenzoate-2-ethylhexyl, p-phenylphenol, p-cumylphenol and the like are used.
[0052]
In addition, the above developers can also use 2 or more types together as needed.
[0053]
The photocuring agent is preferably present in at least one of the first thermoresponsive microcapsule and the second thermoresponsive microcapsule. This is because compared with the case where a photo-curing agent is present outside the microcapsule, a sufficient amount of photo-curing can be achieved with a small amount of photo-curing agent, so that the image forming layer can be made thinner, and the resolution and color development sensitivity are improved. To do. Moreover, when the raw material of the image forming layer is coated on the support and then dried, it may be difficult to form the coating layer if the photocuring agent is outside the microcapsules.
[0054]
The photocuring agent is cured by visible light or ultraviolet light, and it is selected whether to cure by visible light or ultraviolet light depending on the mode of the image forming material and the image forming method. Such a photocuring agent can be constituted by combining a photocuring main agent and a photocuring initiator. In this case, when the photocuring agent is irradiated with visible light or ultraviolet light, active species such as radicals, cations and anions are generated from the photocuring initiator. The photocuring agent is polymerized by the active species, and the curing reaction proceeds. If necessary, functional pigments and functional dyes can be used in combination in order to increase the curing efficiency.
[0055]
As the photocuring main agent, acrylic acid ester polymerizable compound, acrylamide polymerizable compound, methacrylic acid polymerizable compound, methacrylic acid ester polymerizable compound, methacrylamide polymerizable compound, maleic anhydride polymerizable compound, Maleic acid ester-based polymerizable compounds, styrene-based polymerizable compounds, vinyl ether-based polymerizable compounds, vinyl ester-based polymerizable compounds, allyl ether-based polymerizable compounds, and the like can be used. More specifically, (meth) acrylic acid and Its salts, (meth) acrylic acid esters, (meth) acrylamides; maleic anhydride, maleic acid esters; itaconic acid, itaconic acid esters; styrenes; vinyl ethers; vinyl esters; N-vinyl heterocycles Aryl ethers; allyl esters can be used More specifically, among the above, it is preferable to use a photopolymerizable monomer having a plurality of vinyl groups in the molecule. For example, (meth) acrylic acid esters of polyhydric alcohols such as trimethylolpropane and pentaerythritol. A (meth) acrylic acid ester of polyphenols and bisphenols such as resorcinol, pyrogallol and phloroglucinol; (meth) acrylate-terminated epoxy resin; (meth) acrylate-terminated polyester.
[0056]
Among these, ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hydroxypentaacrylate, hexanediol-1,6-dimethacrylate, diethylene glycol dimethacrylate, and the like are particularly preferable.
[0057]
As photocuring initiators, aromatic carbonyl initiators, acetophenone initiators, organic peroxide initiators, organic halide initiators, azo compound initiators, dye-borate complex initiators, metal arenes Complex initiators and the like can be used. More specifically, (η5-2,4-cyclopentadien-1-yl) [(1,2,3,4,5,6-η)-(1-methyl Ethyl) benzene] iron (1+) hexafluorophosphate (1-), 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone, iodonium salt, alkylborate and the like can be used.
[0058]
Moreover, a cationic dye can be used as another example of a photocuring initiator.
[0059]
For example, the general formula [BR ¹ R ² R ^Three R ^Four ] ^- ・ D ⁺ Wherein D represents a cationic dye moiety; R ¹ , R ² , R ^Three And R ^Four Independently represent an alkyl group, aryl group, aralkyl group, alkaryl group, alkenyl group, alkynyl group, cycloalkyl group or allyl group. In particular, a cationic borate that forms a photoreducible complex with a borate anion, and is preferably a cationic methine, polymethine, triarylmethane, indoline, thiazine, oxazine, or acridine dye. Sex cyanine, carbocyanine, hemicyanine, rhodamine and azomethine dyes are preferred.
[0060]
Also, cyanine dyes, diaryl ketone derivatives, polycyclic quinones, benzoin alkyl ethers, alkoxyphenyl ketones, o-acylated oxyimino ketones, phenanthrenequinones, benzophenones, substituted benzophenones, xanthones, thioxanthones, halogenated compounds, chlorosulfonyl and chloro Methyl polynuclear aromatic compounds, chlorosulfonyl and chloromethyl heterocyclic compounds, chlorosulfonyl and chloromethylbenzophenone, fluorenone, haloalkane and the like can be used.
[0061]
The photocuring agent is preferably present in at least one of the first thermoresponsive microcapsule and the second thermoresponsive microcapsule, and particularly preferably present in the second thermoresponsive microcapsule. preferable. This is because some color developing precursors have relatively low solubility, and therefore, if the photo-curing agent is encapsulated in the first thermoresponsive microcapsules, the particle diameter of the first thermoresponsive microcapsules may not be sufficiently small. Because there is.
[0062]
Furthermore, it is preferable if the developer contained in the second thermoresponsive microcapsule is photocurable by visible light or ultraviolet light because the photocuring agent can be reduced or not used. The photocurable developer has a site that reacts with the color precursor and a polymerizable site in one molecule, and has a function of developing the color precursor and, if necessary, a photocuring initiator, It has the effect | action which is used together and hardens | cures by irradiation of light.
[0063]
Resorcin reaction sites, phloroglucine reaction sites, pyrazolone reaction sites, diketone reaction sites, oxydiphenyl reaction sites, naphthol reaction sites, phenol reaction sites, phenol resin reaction sites Examples include a site, a bisphenol-based reaction site, a salicylic acid-based reaction site, and a hydroxybenzoate-based reaction site. Polymeric sites include acrylic ester-based polymerizable sites, acrylamide-based polymerizable sites, methacrylic acid-based polymerizable sites, methacrylic ester-based polymerizable sites, methacrylamide-based polymerizable sites, and maleic anhydride-based polymerization. And a maleic ester-based polymerizable site, a styrene-based polymerizable site, a vinyl ether-based polymerizable site, a vinyl ester-based polymerizable site, and an allyl ether-based polymerizable site.
[0064]
If necessary, other photocuring agents, sensitizing dyes for increasing the curing efficiency, and the like can be used in combination.
[0065]
(The wall of thermoresponsive microcapsule)
The wall of the thermo-responsive microcapsule should be made from the wall of the thermo-responsive permeable membrane, and from the viewpoint of realizing sufficient resolution, color development sensitivity and saturation, and suppressing color mixing, it should be made from a hydrogen-bonding thermo-softening resin. Is preferred. The heat softening resin is a resin having a predetermined glass transition temperature and softening without melting at the predetermined softening temperature. The glass transition temperature and the softening temperature are materials used for image forming materials, color precursors. The temperature is selected in consideration of the temperature at which the developer reacts with the developer (coloring temperature), the presence or absence of a sensitizer, and the like. If the coloring heat-responsive permeable membrane wall is made of a thermosoftening resin, the coloring precursor and the developer can pass through the microcapsule wall without deformation and breakage at the coloring temperature, and these react. The color is developed. Further, the hydrogen bondable resin refers to a resin having a site capable of forming a hydrogen bond in the molecule.
[0066]
The glass transition temperature can be measured by a viscoelastic method, a DSC method, or the like. It can also be calculated using an empirical formula by Fox et al. In the case of the viscoelasticity method, for example, by using Vibron (DDV-II-EA type) manufactured by Toyo Baldwin Co., Ltd., the temperature change of the viscoelasticity is measured in the range from room temperature to 200 ° C. (frequency: 110 Hz). The temperature change of the obtained viscoelasticity is plotted, and the temperature at which the dynamic elastic modulus rapidly decreases can be measured as the glass transition temperature.
[0067]
The glass transition temperature of the hydrogen bondable thermosoftening resin is preferably 20 ° C. or higher, more preferably 50 ° C. or higher, while 180 ° C. or lower is preferable, and 150 ° C. or lower is more preferable.
[0068]
From the above viewpoint, the hydrogen bonding thermosoftening resin is preferably, for example, a polyurethane resin, a polyurea resin, a polyurethane urea resin, or a polyamide resin.
[0069]
(Method for producing thermoresponsive microcapsules)
The first thermoresponsive microcapsule encapsulating the color precursor can be produced by an interfacial polymerization method, an in-situ polymerization method, an emulsion polymerization method, a suspension polymerization method, a spray drying method, or the like. For example, a non-aqueous solvent having a high boiling point and excellent ability to hold the color precursor is mixed with the color precursor. To this, a raw material for a heat-responsive permeable membrane such as isocyanate is added, water and an emulsifier are further added, and the isocyanate and water are reacted in an aqueous system in the presence of the emulsifier. Form a film.
[0070]
The non-aqueous solvent forms oil droplets in the water, the isocyanate and water react on the surface of the oil droplets, and the color precursor is present in the solvent layer. Therefore, the first thermal response that includes the color precursor is included. Microcapsules can be obtained. The solvent is preferably non-aqueous and excellent in oil droplet forming ability. Further, in order to prevent the solvent from volatilizing and forming voids and leaking the contents of the heat-responsive microcapsules during the formation of the heat-responsive permeable membrane wall, a high boiling point is preferable. Furthermore, in order to secure a sufficient amount of the color precursor, those having excellent retention ability of the color precursor are preferable. The holding ability of the color precursor refers to the ability to hold the color precursor in a dissolved and dispersed state and suppress the movement of the color precursor in water. From such a viewpoint, the solvent is preferably dibutyl phthalate (DBP), triphenyl phosphate, tricresyl phosphate, or the like.
[0071]
As the emulsifier, polyvinyl alcohol, gelatin, gum arabic, hexaethylcellulose, methylcellulose, sodium dodecylbenzenesulfonate, and the like can be used from the viewpoint of oil droplet stability.
[0072]
On the other hand, the second thermoresponsive microcapsule encapsulating the developer can be produced with good productivity by the following method, for example.
[0073]
First, the kinematic viscosity at 25 ° C. is 1 to 200 mm. ² The developer is sufficiently pulverized and pulverized in the presence of a non-aqueous low-polarity liquid medium at / second. Thereafter, the high-polarity liquid medium is mixed with the low-polarity liquid medium containing the pulverized and finely divided developer, and the developer is transferred from the low-polarity liquid medium to the high-polarity liquid medium.
[0074]
Immediately after pulverizing the developer in the low polar liquid medium, the developer is dispersed in the low polar liquid medium. When a highly polar liquid medium is added to this dispersion mixed liquid and mixed using a homogenizer or the like, the developer present in the low polar liquid medium layer moves to the high polar liquid medium layer, and the medium in which the developer exists Is replaced from a low polar liquid medium to a high polar liquid medium. The reason for this is not clear, but it is thought to be due to the difference in the affinity of the developer surface with respect to the medium. This phenomenon is also considered to be a kind of phase transition.
[0075]
By adopting such a method, it is not necessary to remove the low-polarity liquid medium from the developer by operations such as filtration and centrifugation, so that the developer is prevented from becoming coarse powder due to agglomeration or the like. . As a result, it is possible to obtain a second thermoresponsive microcapsule that encloses a sufficiently finely-developed developer. If the developer is sufficiently fine powder, sufficient resolution, color development sensitivity and saturation can be realized, and an image forming material in which color mixing is suppressed can be produced.
[0076]
From such a viewpoint, the average particle diameter of the developer is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. On the other hand, the developer is preferably finer, but from the viewpoint of quickly completing the pulverization of the developer and ensuring sufficient productivity, it is preferably 0.01 μm or more, more preferably 0.1 μm or more, It is more preferably 0.3 μm or more, and most preferably 0.5 μm or more. In addition, as the average particle diameter of the developer, the volume average particle diameter can be measured, for example, using a Coulter Multisider (Coulter Electronics, UK).
[0077]
In order to obtain a sufficiently fine developer, it is preferable that the low polar liquid medium is excellent in the pulverizing ability of the developer. From this viewpoint, the kinematic viscosity at 25 ° C. of the low polar liquid medium is 1 mm. ² / Second or more is preferable, while a low viscosity is preferable, specifically 200 mm. ² / Second or less is preferable, 100 mm ² / Second or less is more preferable, 50 mm ² / Second or less is more preferable, 20 mm ² / Second or less is most preferable. The kinematic viscosity of the low polarity liquid medium is measured using a free fall capillary viscometer.
[0078]
Furthermore, if the low-polar liquid medium is non-aqueous, it is possible to prevent moisture from being mixed into the developer and the high-polar liquid medium. Moreover, since it is not necessary to remove water from the developer by operations such as filtration, centrifugation, heating, and decompression, the developer can be prevented from becoming coarse powder due to agglomeration. As a result, it is possible to manufacture the second thermoresponsive microcapsule that contains the developer finely powdered without containing water.
[0079]
From the above viewpoints, the low-polar liquid medium is preferably a liquid oil, and as the liquid oil, liquid paraffin, natural paraffin, synthetic paraffin, paraffin hydrocarbon, alkyl naphthene hydrocarbon, saturation of 5 to 20 carbon atoms. Aliphatic chain hydrocarbons, saturated aliphatic cyclic hydrocarbons having 5 to 20 carbon atoms, aromatic hydrocarbons having 5 to 20 carbon atoms, silicone oils, and the like are preferable, among which liquid paraffin and silicone oils are preferable and inexpensive. For this reason, liquid paraffin is preferred. In addition, these liquid oils can also use 2 or more types together as needed.
[0080]
As the pulverization method, a wet pulverization method is preferable from the viewpoint of sufficiently pulverizing the developer using a bead mill, a ball mill, a roller mill, a rotary pulverizer, a planetary mill, a stirring mill, or the like.
[0081]
The proportion of the developer in the low-polarity liquid medium is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, from the viewpoint of sufficiently pulverizing the developer. From the viewpoint of production efficiency, it is usually 1% by mass or more.
[0082]
When transferring the developer from the low polarity liquid medium to the high polarity liquid medium after pulverization, the concentration of the developer can be sufficiently increased by sufficiently reducing the volume of the high polarity liquid medium used. Can be secured. Furthermore, the particle diameter of the second thermoresponsive microcapsules can be reduced. As a result, sufficient resolution, color development sensitivity, and saturation can be realized, and an image forming material in which color mixing is suppressed can be manufactured.
[0083]
From such a viewpoint, the amount of the highly polar liquid medium used is preferably 100 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 5 parts by mass or less, with respect to 1 part by mass of the low polarity liquid medium. Less than or equal to parts by mass is more preferred, and most preferably less than or equal to 0.5 parts by mass. On the other hand, in order to realize sufficient transfer of the developer, 0.001 part by mass or more is preferable, 0.02 part by mass or more is more preferable, and 0.1 part by mass or more is still more preferable.
[0084]
From the same viewpoint, the concentration of the developer in the highly polar liquid medium is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and further preferably 0.05% by mass or more. 20 mass% or less is preferable, 10 mass% or less is more preferable, and 5 mass% or less is still more preferable.
[0085]
When producing the second thermoresponsive microcapsule encapsulating the photocuring agent, from the viewpoint of reducing the content amount of the second thermoresponsive microcapsule and reducing the particle diameter, and simplifying the production process, etc. It is preferable to use a photo-curing agent as the highly polar liquid medium.
[0086]
Moreover, when using the mixture of a photocuring main agent and a photocuring initiator as a photocuring agent, in order to avoid the unnecessary reaction of a photocuring initiator, it is preferable to use a photocuring main agent as a highly polar liquid medium.
[0087]
As a photo-curing main agent used as a highly polar liquid medium, from the same viewpoint as in the case of the first thermoresponsive capsule, it is preferable that it is non-aqueous and excellent in oil droplet forming ability, and preferably has a high boiling point, The thing which is excellent in the retention capability of a developer is preferable.
[0088]
From these viewpoints, specific examples of the photocuring main agent used as the highly polar liquid medium include acrylic ester-based polymerizable compounds, acrylamide-based polymerizable compounds, methacrylic acid-based polymerizable compounds, methacrylic ester-based polymerizable compounds, and methacrylamide. Polymeric compounds, maleic anhydride polymerizable compounds, maleic ester polymerizable compounds, styrene polymerizable compounds, vinyl ether polymerizable compounds, vinyl ester polymerizable compounds, allyl ether polymerizable compounds, etc. can be used. Among these, (meth) acrylic monomers, (meth) acrylic oligomers, and polyester acrylates (viscosity: 100 to 15,000 Pa · s) are preferable.
[0089]
When the developer is photo-curable, it is not limited to a photo-curing agent as a highly polar liquid medium, and is non-aqueous and excellent in oil droplet formation, has a high boiling point, and is a photo-curable developer. It only has to be excellent in holding ability.
[0090]
After transferring the developer to the highly polar liquid medium, the highly polar liquid medium containing the developer is recovered. When using a photocuring agent as a highly polar liquid medium, the photocuring initiator is mixed after transferring the developer to the photocuring agent, but at that time, a photocuring agent containing the photocuring initiator is separately prepared, By mixing this and a photocuring main agent containing a developer, the accuracy of the addition concentration of the photocuring initiator can be increased.
[0091]
Thereafter, for example, the material of the second thermoresponsive microcapsule is prepared by adding the raw material of the thermoresponsive permeable membrane wall to react with water to form the second thermoresponsive microcapsule wall. Then, water and an emulsifier are mixed with the raw material of the obtained second thermoresponsive microcapsule, and the heat-responsive permeable membrane wall raw material is reacted with, for example, water in an aqueous system in the presence of the emulsifier, so that the thermoresponsive permeable membrane wall is formed. A film is formed to form a second thermoresponsive microcapsule wall.
[0092]
As described above, the second heat-responsive microcapsule including the heat-responsive permeable membrane wall can be obtained by encapsulating the developer and the photo-curing main agent and further encapsulating the photo-curing initiator.
[0093]
(Sensitizer)
As a result of intensive studies on new sensitizers, the present inventors have found that when the wall of the thermoresponsive microcapsule is made of a hydrogen-bonding thermosoftening resin, the acyclic aliphatic polyhydric alcohol is It has been found that it acts as an excellent sensitizer. The reason is not clear, but the acyclic aliphatic polyhydric alcohol acts on the hydrogen-bonding thermosoftening resin, which improves the passability of the color precursor and developer through the thermoresponsive microcapsule wall. It is thought that. For this reason, resolution and color development sensitivity are improved.
[0094]
In particular, the saturation is improved. The reason for this is not clear, but the acyclic aliphatic polyhydric alcohol acts on the hydrogen-bonding thermosoftening resin, which improves the passage of the color-forming precursor and developer through the thermoresponsive microcapsule wall. It is thought that. In addition, it is considered that the acyclic aliphatic polyhydric alcohol affects the hydrogen bond in the thermosoftening resin and lowers the glass transition temperature. Furthermore, it is thought that this is because acyclic aliphatic polyhydric alcohol has a plasticizer action on the thermosoftening resin.
[0095]
In the above case, the color-forming precursor and the developer are considered to react and develop color on the outer surface and the outside of the thermoresponsive microcapsule, so that it is possible to develop a vivid color and improve the saturation. .
[0096]
In addition, even if the color-forming precursor and the developer react and develop colors on the inner surface and inside of the thermoresponsive microcapsules, it is considered that vivid colors can be developed and the saturation is improved.
[0097]
On the other hand, at a temperature lower than the color development temperature, a sufficient barrier property is required for the thermoresponsive microcapsule wall. This is because the coloring precursor and the developer do not pass through the thermoresponsive microcapsule wall, and the coloring needs to be sufficiently suppressed. For this reason, the acyclic aliphatic polyhydric alcohol is preferably present outside the thermoresponsive microcapsule, and preferably non-flowable at a temperature lower than the color development temperature. In this case, the acyclic aliphatic polyhydric alcohol is suppressed from acting on the thermoresponsive microcapsule wall at a temperature lower than the color development temperature, and the color precursor and developer may pass through the thermoresponsive microcapsule wall. It is suppressed. Further, it is preferable that the acyclic aliphatic polyhydric alcohol melts above the coloring temperature and sufficiently acts on the thermoresponsive microcapsule wall.
[0098]
From the above viewpoint, the melting point of the acyclic aliphatic polyhydric alcohol is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, further preferably 50 ° C. or higher, on the other hand, preferably 200 ° C. or lower, and 150 ° C. or lower. More preferably, 100 degrees C or less is still more preferable.
[0099]
The acyclic aliphatic polyhydric alcohol is preferably a polyhydric alkanol alkyl in consideration of the strength of the sensitizing action and the melting point, more preferably a polyhydric alkanol alkyl represented by the following general formula (I). ;
[0100]
[Chemical 1]

[0101]
Where R ¹ Represents an alkyl group having 1 to 12 carbon atoms, R ² ~ R ^Four Independently represents an alkylene group having 1 to 12 carbon atoms.
[0102]
Among these, trimethylol methane, trimethylol ethane, trimethylol propane, trimethylol butane, triethylol methane, triethylol ethane, triethylol propane, triethylol butane and the like are preferable, and trimethylol propane (TMP) is particularly preferable. In addition, if necessary, two or more acyclic aliphatic polyhydric alcohols can be used in combination.
[0103]
By using these acyclic aliphatic polyhydric alcohols, the saturation can be significantly improved as compared with aromatic hydroxy compounds such as PBOP and TBP.
[0104]
The proportion of the acyclic aliphatic polyhydric alcohol in the image forming layer is determined in consideration of the balance of performance, preferably 1% by mass or more, more preferably 2% by mass or more, and 3.5% by mass or more. On the other hand, 35 mass% or less is preferable, 30 mass% or less is more preferable, and 25 mass% or less is still more preferable.
[0105]
(Structure of image forming material)
FIG. 1 shows a specific example of an image forming material in which three image forming layers 211 to 213 are laminated on a support 210 corresponding to the three primary colors, when the image forming layer is a multilayer. Each image forming layer holds a first thermoresponsive microcapsule 222 containing a color precursor 221. In addition, each image forming layer contains second thermoresponsive microcapsules 217 to 219 that enclose developer 214 to 216 corresponding to different colors.
[0106]
Supports include neutral papers, acid papers, coated papers, laminated papers; polyethylene terephthalate films, cellulose acetate films, polyethylene films, polystyrene films, polycarbonate films, and other films; aluminum, zinc, copper A metal plate such as those obtained by subjecting the surface of these supports to various treatments such as surface treatment, undercoating, and metal vapor deposition can be used.
[0107]
The photocuring agent 220 includes a photocuring main agent and a photocuring initiator, and is encapsulated in the second thermoresponsive microcapsule. Then, from the support side, the image forming layer 211 having the second thermoresponsive microcapsule 217 containing the cyan (C) color developer 214 and the magenta (M) color developer 215 are included. The image forming layer 212 having the second thermoresponsive microcapsule 218 and the image forming layer 213 having the second thermoresponsive microcapsule 219 containing the color developing agent 216 for yellow (Y) coloring are laminated. .
[0108]
Note that the order in which the colors are stacked is determined in consideration of the darkness of each color, for example, from the support side in the order of cyan (C), magenta (M), and yellow (Y).
[0109]
The thermoresponsive microcapsules are held in a binder 224. In addition, TMP is dispersed as acyclic aliphatic polyhydric alcohol 223 outside the thermoresponsive microcapsule in the binder. As the binder, polyvinyl alcohol, starch, gelatin, gum arabic, or the like can be used.
[0110]
The image forming layer as described above can be produced as follows. First, the first thermoresponsive microcapsule and the second thermoresponsive microcapsule are respectively prepared to obtain an aqueous emulsion. The obtained aqueous emulsion is mixed, and TMP and a binder are added thereto to prepare an image forming layer raw material. The obtained image forming layer raw material is applied using a blade coater, rod coater, knife coater, roll doctor coater, reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, curtain coater, extrusion coater, etc. The image forming layer is obtained by, for example, air drying at 10 to 60 ° C. to remove moisture.
[0111]
Note that a base, a spectral sensitizer, and the like can be further added to the image forming layer as necessary.
[0112]
Since the thickness of each image forming layer can be a thin film by sufficiently reducing the particle size of the microcapsules, sufficient resolution and color development sensitivity can be realized. Specifically, it is preferably 150 μm or less, more preferably 100 μm or less, further preferably 50 μm or less, and most preferably 30 μm or less. On the other hand, from the viewpoint of ensuring sufficient color development intensity, it is preferably 2 μm or more, more preferably 5 μm or more, and further preferably 8 μm or more.
[0113]
For the same reason, the total thickness of the three image forming layers and the interlayer protective layer is preferably 10 μm or more, more preferably 20 μm or more, further preferably 30 μm or more, while 300 μm or less is preferable, and 200 μm. The following is more preferable, and 100 μm or less is more preferable.
[0114]
Between each image forming layer, interlayer protective layers 225 and 226 made of vinyl acetate / vinyl chloride are formed.
[0115]
Further, the outermost layer may be laminated with a surface protective layer 227 having a thickness of 1 to 5 μm made of polyvinyl alcohol, styrene butadiene rubber, gelatin or the like, if necessary.
[0116]
When a plurality of image forming layers are laminated, the quality of the obtained image is better than that of a single layer.
[0117]
(Image formation method)
A full-color image can be formed on the image forming material produced as described above by a photothermographic method.
[0118]
First, the image forming material is irradiated with light corresponding to the difference in color, and the photocuring agent is cured to form a negative latent image. The exposure for producing the latent image may be performed in one step or in two or more steps, and is determined in consideration of the structure of the image forming material, the obtained image quality and workability, etc. Is done.
[0119]
Next, the image forming material on which the latent image is formed is heated to a predetermined temperature. By heating, the color-forming precursor and the developer encapsulated in the thermoresponsive microcapsule pass through the thermoresponsive permeable membrane wall and diffuse outside the thermoresponsive microcapsule. For this reason, color development occurs when the color-forming precursor and the developer come into contact and react. As a result, the latent image is developed.
[0120]
The heating process for development may be performed in one process or in two or more processes, and is determined in consideration of the structure of the image forming material, the obtained image quality, workability, and the like. . For example, when three image forming layers are formed and the glass transition temperatures of the thermally responsive permeable membranes constituting the walls of the second thermoresponsive microcapsules included in each image forming layer are different, Heat three times and develop for each color. In addition, when the photocuring agent is cured by exposure, it is preferable because development can be performed by one heating. Further, after development, the image may be fixed by further exposing and heating as necessary.
[0121]
As described above, a light curing agent is present in the image forming layer, a non-colored region is cured by exposure to form a negative latent image, and a small amount of heat is applied according to the photothermographic method in which development is performed by heating. An image with sufficient resolution can be obtained by energy.
[0122]
The image forming material of the present invention is suitably used for image forming apparatuses such as copying machines and printers, and is particularly suitable for full-color image formation.
[0123]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not restrict | limited to a following example. Unless otherwise specified, commercially available high-purity products were used as reagents.
[0124]
(resolution)
In consideration of DPI and color balance, the resolution was evaluated in three stages: good (◯), practically usable (Δ), and defective (×).
[0125]
(Color development sensitivity)
The image forming material is kept at a predetermined temperature for 30 seconds to 1 minute, and the state of color development is confirmed. There is sufficient sensitivity (◯), the sensitivity that can withstand practical use (Δ), and the sensitivity is insufficient. It was evaluated in three stages of (×).
[0126]
(saturation)
The image obtained when the coloring precursor and the developer react in the state where only the coloring precursor and the developer are present without the capsule or the like is considered to be the most vivid image and can be obtained by an actual image forming material. The saturation of the image was evaluated in three levels: extremely vivid (◯), vivid (Δ), and dull (×).
[0127]
(Mixed color)
A standard image and an image obtained by color-separating the standard image into cyan (C), magenta (M), and yellow (Y) are formed, and the standard image and the color-separated image are compared, thereby reducing the degree of color mixing. Evaluation was made in three stages: no color mixture was confirmed (◯), a slight color mixture was confirmed (Δ), and color mixture was confirmed (×).
[0128]
(Example 1) Image forming material 1
9 parts by mass of a diazonium salt (trade name: DH-300PF) manufactured by Daito Chemix Co., Ltd. ₆ Was dissolved in 171 parts by weight of DBP as a solvent at 40 ° C., and 160 parts by weight of an isocyanate monomer (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Takenate D110N) was mixed. 279 parts by mass of water and 21 parts by mass of Kuraray polyvinyl alcohol (trade name: PVA117) as an emulsifier were added thereto, emulsified with a homogenizer, reacted at 40 ° C. for 20 hours, and an average particle diameter of 1 μm. A first thermoresponsive microcapsule was obtained. This was purified using an ion exchange resin (manufactured by Organo Corporation, trade name: Amberlite MB-3) to prepare 600 parts by mass of an aqueous emulsion containing 50% by mass of first thermoresponsive microcapsules.
[0129]
On the other hand, as a developer for cyan (C), 2 parts by mass of 2-hydroxy-3-naphthalene-3-carboxylic acid morpholinopropylide is used as a low-polar liquid-liquid medium, and the kinematic viscosity at 25 ° C. is 15 mm. ² In the presence of 18 parts by mass of liquid paraffin / sec, the mixture was pulverized by a bead mill until the average particle size became 0.5 μm. Thereafter, the obtained slurry was mixed with 8 parts by mass of a polyester acrylate (viscosity: 6,000 to 12,000 Pa · s) as a photocuring main agent, and the developer was transferred to the photocuring main agent. In addition, light obtained by dissolving 1% by mass of 1,1′-di-n-heptyl-3,3,3 ′, 3′-tetramethylindodicarbocyanine-triphenyl-n-butylborate as a photocuring initiator 190 parts by mass of a polyester acrylate (viscosity: 6,000 to 12,000 Pa · s) as a curing main agent was prepared and mixed with a curing main agent containing a developer. By adding and reacting isocyanate, water and an emulsifier to the obtained mixture in the same manner as in the case of the first heat-responsive microcapsules, second heat-responsive microcapsules having an average particle size of 2 μm were obtained. Using this, 600 parts by mass of an aqueous emulsion containing 50% by mass of the second thermoresponsive microcapsules was prepared.
[0130]
An electron micrograph of the obtained second thermoresponsive microcapsule is shown in FIG. It can be seen that the second thermoresponsive microcapsules are actually formed.
[0131]
Further, similarly, the developer is 4-hydroxy-1-methyl-2-quinolone for magenta (M) and the photocuring initiator is 1,1′-di-n-heptyl for magenta (M). A second thermoresponsive microcapsule that was −3,3,3 ′, 3′-tetramethylindocarbocyanine triphenyl-n-butyl borate was prepared.
[0132]
The developer is 2,4-dimethoxyacetoacetanilide for yellow (Y), and the photocuring initiator is 3,3-dimethyl-1-heptylindo-3′-heptylthiocyanine for yellow (Y). A second thermoresponsive microcapsule that was -triphenyl-n-butyl borate was prepared.
[0133]
Next, 10 parts by mass of an aqueous emulsion containing the first thermoresponsive microcapsules, 10 parts by mass of the aqueous emulsion containing the second thermoresponsive microcapsules for cyan (C), 1 part by mass of TMP, and a weight average An image forming layer raw material for cyan (C) was prepared by mixing 1 part by weight of polyvinyl alcohol having a molecular weight of 1,700. This was applied onto a support material made of coated paper having a thickness of 200 μm and dried at 40 ° C. to produce an image forming layer for cyan (C) having a thickness of 30 μm.
[0134]
Further, a suspension containing 50% by mass of vinyl acetate / vinyl chloride copolymer (Nisshin Kagaku Co., Ltd., trade name: Vinibrand 380) was applied onto the cyan (C) image-forming layer and applied at 40 ° C. Dried. This was melted at 50 ° C. to form an interlayer protective layer having a thickness of 10 μm.
[0135]
Subsequently, in the same manner as in the case of the cyan (C) image forming layer, after forming the magenta (M) image forming layer, an interlayer protective layer is prepared, and further, the yellow (Y) image forming layer is formed. Formed. Then, a surface protective layer made of polyvinyl alcohol having a thickness of 2 μm was laminated to obtain an image forming material 1.
[0136]
The performance of the obtained image forming material 1 was evaluated under the conditions of a development temperature of 90 ° C. and a development time of 20 seconds. The resolution was ◯, the color development sensitivity was ◯, the saturation was ◯, and the color mixture was ◯.
[0137]
Comparative Example 1 Image forming material 2
An image forming material 2 was produced in the same manner as in the case of the image forming material 1 except that an interlayer protective layer made of polyvinyl alcohol was formed by a casting method.
[0138]
When the performance of the obtained image forming material 2 was evaluated under the conditions of a development temperature of 90 ° C. and a development time of 20 seconds, it was resolution: x, color development sensitivity: Δ, saturation: x, and color mixture: x.
[0139]
Comparative Example 2 Image forming material 3
An image forming material 2 was produced in the same manner as in the case of the image forming material 1 except that an interlayer protective layer made of styrene-butadiene rubber (SBR) was formed by a casting method.
[0140]
When the performance of the obtained image forming material 3 was evaluated under the conditions of a development temperature of 90 ° C. and a development time of 20 seconds, it was resolution: x, color development sensitivity: Δ, saturation: x, and color mixture: x.
[0141]
【The invention's effect】
By forming an interlayer protective layer formed by the melting method at a temperature lower than the glass transition temperature of the thermally responsive permeable membrane wall between the image forming layers, high resolution, color sensitivity and saturation can be realized, and color mixing can be achieved. Can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view for explaining the structure of an image forming material.
FIG. 2 is an electron micrograph of a second thermoresponsive microcapsule.
[Explanation of symbols]
210 Support
214 Developer
215 Developer
216 Developer
217 Second thermoresponsive microcapsule
218 Second thermoresponsive microcapsule
219 Second thermoresponsive microcapsule
220 Light curing agent
221 Color developing precursor
222 1st thermoresponsive microcapsule
223 Acyclic aliphatic polyhydric alcohol
224 binder
225 Interlayer protective layer
226 Interlayer protective layer
227 Surface protective layer

Claims (14)

Two or more image forming layers containing a color former and a color developer are laminated on a support, and an interlayer protective layer made of a vinyl chloride resin is formed between the image forming layers by a melting method. An image forming material characterized by comprising: An image forming layer comprising a first heat-responsive microcapsule comprising a heat-responsive permeable membrane wall and encapsulating a color developing precursor, and a second thermo-responsive microcapsule comprising a thermo-responsive permeable membrane wall and encapsulating a developer. Two or more layers are laminated on a support, and an interlayer protective layer made of a vinyl chloride resin is formed between the image forming layers by a melting method at a temperature lower than the glass transition temperature of the thermally responsive permeable membrane wall. An image forming material, which is formed.   The interlayer protective film is produced by applying a suspension of a raw material resin for the interlayer protective layer, and melting the coated layer at a temperature lower than the glass transition temperature of the thermally responsive permeable film wall to form a film. The image forming material according to claim 2.   The interlayer protective film is manufactured by applying a paste resin of a raw material resin for the interlayer protective layer, and melting the coated layer at a temperature lower than the glass transition temperature of the thermally responsive permeable film wall. The image forming material according to claim 2. The thermoresponsive transmission membrane wall, the image forming material according to any one of claims 2 to 4, characterized in that it consists of hydrogen bonding of heat-softenable resin. Outside the first heat-responsive microcapsules and the second heat-responsive microcapsules, acyclic image forming material according to any one of claims 2 to 5, further comprising an aliphatic polyhydric alcohol. Second heat-responsive microcapsules image forming apparatus according to any one of claims 2 to 6, characterized in that the enclosing light hardener. The second thermoresponsive microcapsule is:
Crushing the photocurable developer in the presence of liquid oil having a kinematic viscosity at 25 ° C. of 1 to 200 mm ² / sec;
Mixing the liquid oil containing the pulverized photocurable developer and a highly polar liquid medium, and transferring the developer from the liquid oil to the highly polar liquid medium. the image forming material according to any one of claims 2 to 7, characterized in that it is manufactured by the method. The image forming material according to claim 8 , wherein the curing agent includes a photocuring main agent and a photocuring initiator, and the highly polar liquid medium is the photocuring main agent. The developer An image forming material according to any one of claims 1 to 9, wherein the photocurable. Three image forming layers are laminated on the support,
An image forming layer having a second thermoresponsive microcapsule containing a cyan (C) color developer, and an image having a second thermoresponsive microcapsule containing a magenta (M) color developer and forming layer, yellow (Y) one of claims 1 to 10 and an image forming layer having a second thermally responsive microcapsules encapsulating a color developer for color development is characterized in that it is laminated in any order An image forming material according to any one of the above. The image forming material according to claim 11, wherein each layer of the image forming layer has a thickness of 2 to 150 μm. The image forming material according to any one of claims 1 to 12, wherein the thickness of the interlayer protective layer is 1 to 30 [mu] m. Light is irradiated to the image forming material according to any one of claims 1 to 13, forming a latent image by curing the light curing agent,
The image forming material on which the latent image is formed is heated, and at least one of the color precursor and the developer is passed through the thermally responsive permeable membrane wall, and the color precursor, the developer, And a step of developing the latent image by causing the color precursor to develop color.

Images