JP3967841B2 - Inkjet image receiving material and method for producing the same - Google Patents

Description

【００２７】
前記一般式（Ｉ）において、Ｒ１ は、水素原子又は炭素数１〜６の低級アルキル基を表す。Ｌは、炭素数１〜２０の２価の連結基を表す。Ｅは、炭素原子との二重結合を有する窒素原子を構成成分として含むヘテロ環を表し、これらの中でも下記に示すイミダゾール基が特に好ましい。ｎは、０又は１を表す。
【００２８】
【化２】

【００２９】
前記イミダゾール基を有するカチオン性ポリマー媒染剤を用いると、色素の染着性、光堅牢性の点で有利である。
【００３０】
これらのカチオン性ポリマー媒染剤は、前記プラス荷電微粒子及び前記マイナス荷電微粒子を含有する多孔質構造の受像層に使用することができるが、別の層、例えば該多孔質構造の受像層の下層に、使用することも好ましい。
【００３１】
前記退色防止剤としては、例えば、酸化防止剤、紫外線吸収剤、金属錯体、硬膜剤などが挙げられる。
【００３２】
前記酸化防止剤としては、例えば、クロマン系化合物、クマラン系化合物、フェノール系化合物（例えばヒンダードフェノール類）、ハイドロキノン誘導体、ヒンダードアミン誘導体、スピロインダン系化合物、また、特開昭６１−１５９６４４号記載の化合物などが挙げられる。
【００３３】
前記紫外線吸収剤としては、例えば、ベンゾトリアゾール系化合物（米国特許第３，５３３，７９４号など）、４−チアゾリドン系化合物（米国特許第３，３５２，６８１号など）、ベンゾフェノン系化合物（特開昭４６−２７８４号など）、その他特開昭５４−４８５３５号、同６２−１３６６４１号、同６１−８８２５６号等に記載の化合物、また、特開昭６２−２６０１５２号記載の紫外線吸収性ポリマーなどが挙げられる。
【００３４】
前記金属錯体としては、例えば、米国特許第４，２４１，１５５号明細書、同４，２４５，０１８号明細書第３〜３６欄、同４，２５４，１９５号明細書第３〜８欄、特開昭６２−１７４７４１号公報、同６１−８８２５６号公報第（２７）〜（２９）頁、同６３−１９９２４８号公報、特開平１−７５５６８号公報、同１−７４２７２号公報等に記載されている化合物などが挙げられる。
【００３５】
前記硬膜剤としては、例えば、米国特許第４，６７８，７３９号第４１欄、特開昭５９−１１６６５５号、同６２−２４５２６１号、同６１−１８９４２号等に記載の硬膜剤が挙げられる。
前記硬膜剤の具体例としては、アルデヒド系硬膜剤（ホルムアルデヒドなど）、アジリジン系硬膜剤、エポキシ系硬膜剤、ビニルスルホン系硬膜剤（Ｎ，Ｎ’−エチレンービス（ビニルスルホニルアセタミド）エタンなど）、Ｎ−メチロール系硬膜剤（ジメチロール尿素など）、あるいは高分子硬膜剤（特開昭６２−２３４１５７号などに記載の化合物）などが挙げられる。
【００３６】
前記退色防止剤の有用例としては、特開昭６２−２１５２７２号公報第（１２５）〜（１３７）頁に記載されている。
【００３７】
前記蛍光増白剤としては、例えば、Ｋ．Ｖｅｅｎｋａｔａｒａｍａｎ編「Ｔｈｅ Ｃｈｅｍｉｓｔｒｙ ｏｆ Ｓｙｎｔｈｅｔｉｃ Ｄｙｅｓ」第Ｖ巻第８章、特開昭６１−１４８７５２号などに記載されている化合物などが挙げられ、具体的には、スチルベン系化合物、クマリン系化合物、ビフェニル系化合物、ベンゾオキサゾリル系化合物、ナフタルイミド系化合物、ピラゾリン系化合物、カルボスチリル系化合物などが挙げられる。
前記蛍光増白剤は、前記退色防止剤と併用することができる。
【００３８】
また、本発明においては、塗布助剤、剥離性改良、スベリ性改良、帯電防止、現像促進等の目的で、種々の界面活性剤を前記添加剤として使用してもよい。
【００３９】
前記界面活性剤の具体例としては、特開昭６２−１７３４６３号、同６２−１８３４５７号等の各公報に記載されている。
【００４０】
また、本発明においては、スベリ性改良、帯電防止等の目的で、有機フルオロ化合物を使用してもよい。
前記有機フルオロ化合物の代表例としては、特公昭５７−９０５３号公報第８〜１７欄、特開昭６１−２０９４４号公報、同６２−１３５８２６号公報等に記載されているフッ素系界面活性剤、フッ素油などのオイル状フッ素系化合物もしくは四フッ化エチレン樹脂などの固体状フッ素化合物樹脂などの疎水性フッ素化合物などが挙げられる。
【００４１】
更に、本発明において、マット剤を使用してもよい。前記マット剤としては、例えば、二酸化ケイ素、ポリオレフィン又はポリメタクリレートなどの特開昭６１−８８２５６号公報（２９）頁記載の化合物の外、ベンゾグアナミン樹脂ビーズ、ポリカーボネート樹脂ビーズ、ＡＳ樹脂ビーズなどの特開昭６３−２７４９４４号公報、同６３−２７４９５２号公報に記載の化合物などが挙げられる。
【００４２】
前記受像層は、多孔質構造であるが、該受像層が多孔質構造を有しているか否かは、例えば、水銀ポロシメーター（ポアサイザー９３２０−ＰＣ２、島津製作所（株）製）を用いて空隙率を測定することにより確認することができる。
【００４３】
前記受像層の空隙率としては、前記プラス荷電微粒子及び前記マイナス荷電微粒子の一次粒子径や、前記水性バインダーの量等により変動するため一概に規定することはできないが、４０〜８０％であるのが好ましく、４５〜７０％であるのがより好ましい。
前記空隙率が、４０％未満であると、インクの吸収速度が十分でないことがあり、８０％を超えると、ヒビ割れ等を生じ易くなる。
【００４４】
前記受像層は、単層構造であってもよいし、積層構造であってもよい。
前記受像層の厚みは、インクの液滴を全て吸収するだけの吸収容量があることが好ましく、具体的には、塗膜の空隙率との関連で決めることが好ましい。例えば、インク量８ｎｌ／ｍｍ２ の場合、空隙率が６０％であれば該厚みとしては約１５μｍ以上あることが好ましい。前記受像層の厚みとしては、５〜５０μｍであるのが好ましい。前記受像層の厚みが、５０μｍを超えるとヒビ割れが起こり、カールが大きくなることがあり、５μｍ未満であるとインクの吸収性が悪く、保存中に色素の滲みが起こることがある。
【００４５】
（その他の層）
前記その他の層としては、特に制限はなく、公知のものの中から適宜選択することができ、例えば、保護層、剥離層、カール防止層などが挙げられ、これらの中でも特に保護層をインクジェット用受像材料の表面に有するのが好ましい。
【００４６】
本発明のインクジェット用受像材料は、以下の本発明のインクジェット用受像材料の製造方法により好適に製造することができる。
本発明のインクジェット用受像材料の製造方法においては、前記支持体上に、受像層用液を塗布し乾燥して、多孔質構造の受像層を形成する。
【００４７】
前記受像層用液は、前記プラス荷電微粒子と、前記マイナス荷電微粒子と、前記水性バインダーとを少なくとも含有し、必要に応じて適宜選択した前記その他の成分を含有する。
【００４８】
前記受像層用液中に配合される前記プラス荷電微粒子及び前記マイナス荷電微粒子の含有量としては、前記水性バインダー１重量部に対して、０．５〜１０重量部が好ましく、１〜６重量部がより好ましい。
前記含有量が、０．５重量部未満であると、前記受像層を多孔質構造にすることができないことがあり、１０重量部を超えると、前記受像層の強度が低下し、乾燥時にヒビ割れ等が発生するおそれがある。一方、前記含有量が前記数値範囲内にあると、そのようなことはなく、インクの吸収性が高く、印字後のインクの乾燥が速いインクジェット用受像材料が得られる点で有利である。
【００４９】
前記受像層用液は、例えば、以下のようにして調製することができる。即ち、前記プラス荷電微粒子と、前記マイナス荷電微粒子と、前記水性バインダーと、適宜選択した前記その他の成分とのそれぞれの所定量を、分散媒に添加し、混合することにより調製することができ、好ましくは、前記プラス荷電微粒子の分散液と、前記マイナス荷電微粒子の分散液と、前記水性バインダーの水溶液又は水分散液と、前記その他の成分の水溶液又は水分散液とを、混合することにより調製することができる。
【００５０】
前記分散媒としては、特に制限はなく、目的に応じて適宜選択することができるが、例えば、水、メタノール、エタノール等のアルコール類、これらの混合液等の水系媒体が好適に挙げられる。
【００５１】
前記受像層用液中における前記プラス荷電微粒子及び前記マイナス荷電微粒子の均一な分散は、例えば、前記分散媒（例えば水）１００重量部に、該プラス荷電微粒子及び該マイナス荷電微粒子の２〜２０重量部を添加し、十分に前記分散媒である水に馴染ませてから、分散機を用いてこれらの微粒子を水中に分散させることにより達成される。また、前記プラス荷電微粒子と前記マイナス荷電微粒子とを別々に分散して分散液を調製した後、該プラス荷電微粒子の分散液を攪拌しながら、該マイナス荷電微粒子の分散液を少量づつ添加していくことにより達成される。
【００５２】
前記分散機としては、特に制限はなく、目的に応じて適宜選択することができるが、例えば、機械的に直接力を加えて分散する各種ミル、大きな剪断力を有する高速攪拌型分散機、高強度の超音波エネルギーを与える分散機などのいずれであってもよい。これらの具体例としては、ボ−ルミル、サンドグラインダーミル、ビスコミル、コロイドミル、ホモジナイザー、ディゾルバーポリトロン、ホモミキサー、ホモブレンダー、ケディミル、ジェットアジター、毛細管式乳化装置、液体サイレン、電磁歪式超音波発生機、ボールマン笛を有する乳化装置などが挙げられる。
【００５３】
なお、前記水性バインダーは、別にその水溶液又は水分散液を調製しておき、前記プラス荷電微粒子分散液及び前記マイナス荷電微粒子分散液の少なくとも一方に混合してもよい。前記水性バインダーは、予め前記プラス荷電微粒子の分散液中に混合しておき、この分散液を攪拌しながら、前記マイナス荷電微粒子の分散液を少量づつ添加しておくのが、多孔質構造の受像層を形成する点で好ましい。
また、前記プラス荷電微粒子及び前記マイナス荷電微粒子を分散させる際には、前記分散媒に、予め所定量の前記水性バインダーを添加させておき、該水性バインダーを分散安定化剤（保護コロイド）として作用させることも好ましい。
【００５４】
以上のようにして調製した受像層用液は、前記支持体上に塗布されて塗布層が形成される。
前記受像層用液の塗布は、公知の塗布方法に従って公知の塗布手段を用いて行なうことができ、該塗布手段としては、例えば、エアードクターコーター、ブレードコーター、ロッドコーター、ナイフコーター、スクイズコーター、リバースロールコーター、バーコーターなどが挙げられる。
【００５５】
前記支持体上に塗布形成された前記塗布層は、乾燥され、該塗布層より前記分散媒等の液成分（水分）が除去されて、その結果、該支持体上に前記多孔質構造である受像層が形成され、本発明のインクジェット用受像材料が製造される。
【００５６】
前記乾燥の条件としては、温度が２５〜１８０℃であり、時間が５〜２０分程度で行われる。
前記受像層用液において前記水性バインダーとして、その水溶液又は水分散液が低温でゲル化するポリマー（例えば、ゼラチン、κ−カラギーナン、ほう酸又はその塩をゲル化剤として用いたポリビニルアルコールなど）を用いる場合、例えば、０〜１５℃でセットした後、２５〜５０℃で乾燥する（セット乾燥という）ことができる。
【００５７】
前記乾燥の際、前記分散媒である水等が、揮発、除去され、前記水性バインダーが硬化して被膜を形成し、前記プラス荷電微粒子及び前記マイナス荷電微粒子が、部分的に固定されて多孔質構造が形成される。このように、これらの微粒子間を空隙を有するようにして固定し、多孔質構造を形成することにより、前記受像層をインクの吸収性に優れたものにすることができ、高品質のインクジェット用受像材料が得られる点で有利である。
【００５８】
以上のように、前記乾燥において、前記分散媒等の水分が除去されると、前記プラス荷電微粒子とマイナス荷電微粒子との相互作用が強くなり、これらは電気的に互いの吸引力が大きくなるように、かつ電気的に安定になるように、交互に数珠状に連なった状態で固定され、強度に優れ、空隙率が高く、均一な空孔を有する多孔質構造の前記受像層が形成される。このとき、前記プラス荷電微粒子よりも前記マイナス荷電微粒子の使用量が少ないため、該受像層は、全体としてプラスに荷電している状態になっている。
【００５９】
本発明のインクジェット用受像材料の製造方法によると、特別な処理を行なうことなく、前記プラス荷電微粒子及び前記マイナス荷電微粒子の相互作用により、大きな三次元空隙を有する多孔質構造の前記受像層を容易に前記支持体上に形成することができ、該受像層は、インク中に含まれる色材の受容性に優れた表面電荷を有するので、高品質のインクジェット用受像材料を製造することができる。
【００６０】
【実施例】
以下に、本発明の実施例を説明するが、本発明はこれらの実施例に何ら限定されるものではない。
（参考例１）
＜受像層用液の調製＞
下記組成の受像層用液を調製した。
−受像層用液の組成−
ポリビニルアルコール・・・・・・・・・・・・・・・・・ １０重量部
（クラレ（株）製、ＰＶＡ４２０）
硫酸バリウム超微粒子（プラス荷電微粒子）・・・・・・・ ４０重量部
（堺化学工業（株）製、バリファインＢＦ２０）
シリカ超微粒子（マイナス荷電微粒子）・・・・・・・・・１．２重量部
（アエロジル社製、アエロジル２００）
水・・・・・・・・・・・・・・・・・・・・・・・・・・３００重量部
即ち、硫酸バリウム超微粒子４０重量部及びシリカ超微粒子１．２重量部を、水（１６０重量部）に添加し、高速回転コロイドミル（クレアミックス、エム・テクニック（株）製）を用いて、１０，０００ｒｐｍで２０分間分散させた後、ポリビニルアルコール水溶液（前記水の残り１４０重量部にポリビニルアルコール１０重量部を溶解させたもの）を加えて、上記と同じ条件で分散を行い、受像層用液を調製した。
【００６１】
前記受像層用液を、厚みが１００μｍであり、両面にコロナ放電処理がなされた二軸延伸ポリエチレンテレフタレートフィルム上に、エアーナイフコーターを用いて塗布し、熱風乾燥機により７０℃（風速５ｍ／秒）で１０分間乾燥させた。これにより乾燥後の厚みが１５μｍである受像層を形成し、インクジェット用受像材料を得た。
前記受像層の空隙率を水銀ポロシメーター（ポアサイザー９３２０−ＰＣ２、島津製作所（株）製）を用いて測定したところ、５３％であった。
【００６２】
（実施例２）
硫酸バリウム超微粒子（プラス荷電微粒子、バリファインＢＦ２０、一次粒子径０．０５μｍ）８００ｇを３２００ｇの水に添加し、粗分散した後、ダイノミルにて平均粒径が０．１５μｍ以下になるまで分散して、プラス荷電微粒子の分散液（２０重量％）を得た。
次に、このプラス荷電微粒子分散液１５０重量部を攪拌しながら、７重量％ポリビニルアルコール（クラレ（株）製、ＰＶＡ４２０）水溶液１００重量部を添加し、更にコロイダルイシリカ（マイナス荷電微粒子、日産化学（株）製、スノーテックスＣ）２０重量％液の５重量部を攪拌しながら少量づつ添加して受像層用塗布液を調製した。
ポリビニルアルコール水溶液でサイジングした坪量１００ｇ／ｍ²の原紙の裏面に３０μｍのポリエチレン層を、表面に二酸化チタンを１０重量％含有するポリエチレン層４０μｍを溶融押出コーティングしたポリエチレンラミネート紙上に前記受像層用塗布液を実施例１と同様にして塗布してインクジェット用受像材料を得た。
受像層の空隙率を参考例１と同様にして測定したところ、６５％であった。
【００６３】
（参考例３）
実施例２において、硫酸バリウム分散液を、アルミナ（プラス荷電微粒子、日産化学（株）製、ＡＬ−２００）に代えた外は、実施例２と同様にしてインクジェット用受像材料を作製した。
受像層の空隙率を実施例２と同様にして測定したところ、６０％であった。
【００６４】
（比較例１）
参考例１において、シリカ超微粒子を用いなかった外は、参考例１と同様にしてインクジェット用受像材料を作製した。
受像層の空隙率を実施例１と同様にして測定したところ、３１％であった。
【００６５】
（比較例２）
実施例２において、コロイダルシリカを用いなかった外は、実施例２と同様にしてインクジェット用受像材料を作製した。
受像層の空隙率を実施例２と同様にして測定したところ、３８％であった。
【００６６】
（比較例３）
参考例３において、コロイダルシリカを用いなかった外は、参考例３と同様にしてインクジェット用受像材料を作製した。
受像層の空隙率を参考例３と同様にして測定したところ、４０％であった。
【００６７】
以上のようにして作製した各インクジェット用受像材料について、以下の性能を評価し、その結果を表１に示した。
【００６８】
（１）インクの吸収速度
インクジェットプリンター（ＰＩＸＥＬ ＳＥＴ、キャノン（株）製）により、得られた各インクジェット用受像材料に黒ベタ印字を行った直後（約１０秒後）に紙を接触押印し、該紙への転写の有無により下記のように判定した。
◎・・・・紙にインクが全く転写されなかった。
○・・・・紙にインクが極めてわずか転写された。
△・・・・紙にインクが少し転写された。
×・・・・紙へのインクの転写が著しかった。
【００６９】
（２）画像の滲み
前記インクジェットプリンターにより、得られた各インクジェット用受像材料に文字印字を行い、印字２時間後の画像の滲みを評価した。更に、この印字サンプルを４０℃９０％ＲＨの高温高湿条件下で２日間放置した後、画像の滲みを評価した。
Ａ・・・・全く滲みなし
Ｂ・・・・少し滲みあり
Ｃ・・・・滲み大
【００７０】
（３）色素の染着性
前記インクジェットプリンターにより、得られた各インクジェット用受像材料にマゼンタ印字を行い、乾燥後、３０秒間水洗した。その際、水洗前後の印字濃度をマクベス濃度計により測定し、水洗により流出しないで残存した色素の残存率（％）を算出して染着性を評価した。数値が大きいほど染着性に優れている。用いたマゼンタ色素は、マイナス電荷を有する酸性染料であり、インクジェット用受像材料における受像層表面がプラス荷電微粒子が多く存在する方が色素残存率が大きくなるため、この評価により受像層表面におけるプラス荷電微粒子の存在状態を検知することができる。
【００７１】
【表１】

【００７２】
表１に示す結果より、実施例２のインクジェット用受像材料の受像層は、空隙率が高く、インクの吸収速度に優れ、画像の滲みもなく、優れた特性を有していた。一方、マイナス荷電微粒子を含有しない比較例１〜３のインクジェット用受像材料は、実施例２のインクジェット用受像材料に比べて、空隙率が低く、インクの吸収速度が遅く、画像の滲みも極わずかであるが観察された。
【００７３】
【発明の効果】
本発明によると、インクの吸収性が高く、色素の染着性に優れるインクジェット用受像材料、及び、該インクジェット用受像材料を簡便に製造し得る方法を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inkjet image receiving material and a method for producing the same, and more specifically, an inkjet image receiving material having high ink absorptivity and excellent dyeing property, and the inkjet image receiving material can be easily produced. Regarding the method.
[0002]
[Prior art]
Inkjet image-receiving materials have characteristics such as high saturation of formed images, the ability of dyes to be dyed firmly on the inkjet image-receiving material, quick-drying and no ink bleeding, etc. Is required.
In the past, in order to meet these requirements, for example, a polymer mordant has been used for the image receiving layer in the image receiving material for inkjet. However, in this case, although the saturation of the formed image is high and the transparency is excellent, there is a problem that the ink is poor in absorbability and quick drying, and ink bleeding is likely to occur. On the other hand, inorganic ultrafine particles have also been used for the ink image-receiving layer in the ink-jet image-receiving material. In this case, the ink is formed although it has excellent ink absorbability and quick-drying properties and does not cause ink bleeding or the like. There is a problem that the saturation of the image is not sufficient, vivid color reproduction is impossible, and bleeding occurs when the image is stored for a long time or under high humidity.
[0003]
As the image receiving layer having excellent physical characteristics, for example, JP-A-7-276789 describes a color material receiving layer having a three-dimensional network structure having a high porosity. However, in this case, it cannot be said that the ink absorbability and the dyeing property are sufficient, and an ink jet image receiving material excellent in these characteristics and a method for easily producing the ink jet image receiving material are desired. It was.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide an ink jet image receiving material having high ink absorbability and excellent dyeing property, and a method for easily producing the ink jet image receiving material.
[0005]
[Means for Solving the Problems]
  Means for solving the above-mentioned problems are as follows. That is,
<1> An image receiving layer is provided on a support, and the image receiving layer isThe average particle size is 0.3 μm or less,Fine particles of barium sulfate having a positive charge on the surface;The average particle size is 0.3 μm or lessColloidal silica fine particles0.1 to 20 parts by weight of colloidal silica fine particles per 100 parts by weight of barium sulfate fine particles having a positive charge on the surfaceAn ink jet image receiving material having a porous structure.
<2> On the support,The average particle size is 0.3 μm or less,Fine particles of barium sulfate having a positive charge on the surface;The average particle size is 0.3 μm or lessApply and dry a liquid for an image receiving layer containing colloidal silica fine particles and an aqueous binder,0.1 to 20 parts by weight of colloidal silica fine particles are contained per 100 parts by weight of the barium sulfate fine particles having a positive charge on the surface.A method for producing an image receiving material for inkjet, comprising forming an image receiving layer having a porous structure.
<3> The aqueous binder is polyvinyl alcohol <2> A method for producing an image receiving material for ink jet recording according to>.
[0006]
  The ink-jet image receiving material according to <1> has an image receiving layer on a support, and the image receiving layer contains barium sulfate fine particles having a positive charge on the surface and colloidal silica fine particles. Therefore, in the image receiving layer, the barium sulfate fine particles and the colloidal silica fine particles having a positive charge on the surface are made electrically stable so that the mutual attractive force is increased by electrical interaction. And are fixed in a state of being alternately arranged in a bead shape. For this reason, the image receiving layer has a porous structure, is excellent in strength, has a high porosity, and has uniform pores.In addition, since 0.1 to 20 parts by weight of colloidal silica fine particles are contained with respect to 100 parts by weight of positively charged barium sulfate fine particles on the surface, the electric conductivity between the barium sulfate fine particles and the colloidal silica fine particles in the image receiving layer. The balance of interaction is good and the whole is positively charged. Furthermore, since the average particle diameter of the barium sulfate fine particles and colloidal silica fine particles having a positive charge on the surface is 0.3 μm or less, the image receiving layer has a porous structure having uniform pores.
[0010]
  <2In the method for producing an image receiving material for ink jet according to>The average particle size is 0.3 μm or less,Fine particles of barium sulfate having a positive charge on the surface;The average particle size is 0.3 μm or lessA liquid for an image receiving layer containing colloidal silica fine particles and an aqueous binder is applied and dried to form an image receiving layer having a porous structure. When moisture is removed during the drying of the image-receiving layer solution, the interaction between the positively charged barium sulfate fine particles and the colloidal silica fine particles is strengthened on the surface, and these are electrically attracted to each other. It exists in the image receiving layer in a state where it is fixed in a state of being alternately arranged in a bead shape so as to be large and electrically stable. Therefore, the image receiving layer is formed into a porous structure having excellent strength, a high porosity, and uniform pores.
[0011]
  <3In the method for producing an image receiving material for ink jet according to <4>, since the aqueous binder is polyvinyl alcohol, the dispersibility of the fine particles having a positive charge on the surface and the fine particles having a negative charge on the surface may be reduced when forming the image receiving layer. Good and these interactions are stronger.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
  The ink-jet image receiving material of the present invention is formed on a support.The average particle size is 0.3 μm or less,Fine particles of barium sulfate having a positive charge on the surface;The average particle size is 0.3 μm or lessColloidal silica fine particles,0.1 to 20 parts by weight of colloidal silica fine particles per 100 parts by weight of barium sulfate fine particles having a positive charge on the surfaceIt has at least an image receiving layer having a porous structure, and further contains other layers as necessary.
[0013]
(Support)
There is no restriction | limiting in particular as said support body, According to the objective, it can select suitably from well-known things, For example, the film thru | or sheet | seat formed with paper, a synthetic polymer, a metal, cloth, glass etc. Is mentioned. Among these, paper and films or sheets formed of synthetic polymers are common.
Examples of the paper include pulp paper, synthetic paper made from polypropylene, mixed paper made from synthetic resin such as polyethylene and natural pulp, Yankee paper, baryta paper, coated paper (particularly cast coated paper), and the like. Can be mentioned.
Examples of the synthetic polymer include polyethylene terephthalate, polycarbonate, polyvinyl chloride, polystyrene, polypropylene, polyimide, and celluloses (for example, triacetyl cellulose). These synthetic polymers may contain a pigment such as titanium oxide.
[0014]
Further, at least one of the surfaces of the film or sheet may be laminated with a synthetic polymer such as polyethylene, a hydrophilic binder, a semiconductive metal oxide such as alumina sol or tin oxide, and other antistatic agents. It may be applied with an agent or the like.
In the present invention, in addition to these supports, the supports described in JP-A-62-253159, pages (29) to (31) can be used.
There is no restriction | limiting in particular as thickness of the said support body, Although it can select suitably according to the objective, Usually, it is about 50-300 micrometers, and 100-200 micrometers is preferable.
[0015]
(Image receiving layer)
  The image receiving layer isThe average particle size is 0.3 μm or less,Fine particles of barium sulfate having a positive charge on the surface;The average particle size is 0.3 μm or lessIt contains at least colloidal silica fine particles, and further contains an aqueous binder and other components as appropriate.
[0016]
-Has a positive charge on the surfaceBarium sulfateFine particles
  SaidHas a positive charge on the surfaceBarium sulfateFine particles (hereinafter,Barium sulfate particles with positive charge on the surfaceSometimes referred to as “plus charged fine particles”)ofAmong these, barium sulfate treated so that the surface has a positive charge is preferable from the viewpoints of excellent light resistance, good dispersibility, and easy formation of a porous image-receiving layer.
  The surface has a positive chargeBarium sulfate fine particlesMay be prepared as appropriate or commercially available. Moreover, these may be used individually by 1 type and may use 2 or more types together.
  The surface has a positive chargeBarium sulfate fine particlesIs excellent in dyeing properties of pigments having an anionic group (acidic dyes). Therefore, when the positively charged fine particles are used in the image receiving layer, the pigments do not bleed and they do not bleed even when stored under high humidity. As a result, an ink-jet image receiving material having a high saturation of the printed image and vivid color reproduction can be obtained.
[0017]
−Colloidal silicaFine particles
  SaidColloidal silica fine particlesFine particles with negative charge on the surfaceIs(Less thanColloidal silica particlesSometimes referred to as “negatively charged fine particles”).Colloidal silica fine particlesIn terms of excellent transparency, it is easy to form a porous image-receiving layer, etc.GoodGood.
  SaidColloidal silicaThe fine particles may be appropriately prepared or commercially available. Moreover, these may be used individually by 1 type and may use 2 or more types together.
[0018]
  The content of the negatively charged fine particles in the image receiving layer is 0.1 to 20 parts by weight with respect to 100 parts by weight of the positively charged fine particles.And1 to 10 parts by weight is particularly preferable.
  When the content is less than 0.1 parts by weight, an image receiving layer having a porous structure may not be formed. When the content exceeds 20 parts by weight, aggregation may occur and in some cases, gelation may occur. .
[0019]
  As the size of the positively charged fine particles and the negatively charged fine particles, the primary particle diameter is 0.3 μm or less.And0.2 μm or less is more preferable, and 0.1 μm or less is particularly preferable.
  When the primary particle diameter of the positively charged fine particles and the negatively charged fine particles exceeds 0.3 μm, the glossiness of the surface of the ink-jet image receiving material is lowered, and further, the ink absorbability / dyeability, dye bleeding, etc. Performance may be reduced.
  The primary particle size can be measured using, for example, an electron micrograph or a particle size measuring device using laser light.
[0020]
The positively charged fine particles and the negatively charged fine particles are generally obtained by appropriately controlling pH conditions during the production of the inorganic fine particles. For example, when the magnesium oxide has a pH of 3 to 10, the positively charged fine particles are obtained. When the pH of the lead oxide is 4 to 10, positively charged fine particles are obtained. When the pH of the zirconium oxide is 3 to 5, the positively charged fine particles are obtained.
[0021]
Whether the inorganic fine particles are positively charged fine particles or negatively charged fine particles can be confirmed, for example, by measuring a zeta potential.
[0022]
-Aqueous binder-
Examples of the aqueous binder include those having a hydrophilic structural unit. Examples of the hydrophilic structural unit include a resin having a hydroxyl group, a resin having an ether bond, a resin having an amide group or an amide bond, or an aqueous solution thereof. Gelatin, carrageenan, etc. that have gelling ability at low temperature, or polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPAm), polyvinyl having amino group, imino group, tertiary amine and quaternary ammonium salt Pyridine, and the like.
[0023]
Examples of the resin having a hydroxyl group include polyvinyl alcohol (PVA), cellulose resins (methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), etc.), chitins, starch and the like. Is mentioned.
Examples of the resin having an ether bond include polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), and polyvinyl ether (PVE).
Examples of the resin having an amide group or an amide bond include polyacrylamide (PAAM), poly N-vinylacetamide (PNVA), and polyvinylpyrrolidone (PVP).
In the present invention, the aqueous binder may be used alone or in combination of two or more. In the present invention, among these, the cellulose-based resin, the polyvinyl resin, and the polyvinyl resin in that the dispersion liquid (coating liquid) in which the positively charged fine particles and the negatively charged fine particles are dispersed is difficult to aggregate at the time of manufacturing the image receiving material for inkjet. Alcohol is preferable, and polyvinyl alcohol is particularly preferable in that it can be set and dried at a low temperature by adding boric acid.
[0024]
-Other ingredients-
The other components are not particularly limited, and known additives can be used as long as the effects of the present invention are not impaired. For example, JP-A-62-253159, page (25), Examples thereof include those described in JP-A-62-245253, and further, a cationic polymer for adjusting the physical properties of the image-receiving layer liquid for forming the image-receiving layer and for improving the properties of the image-receiving layer. A mordant is preferably used, and examples include a fading inhibitor, a fluorescent brightener, a plasticizer, and a slip agent.
[0025]
As the cationic polymer mordant, for example, a cationic polymer mordant described in JP-A-63-103240 is preferably exemplified, and one example thereof is a cationic polymer mordant represented by the following general formula (I). Is mentioned.
Formula (I)
[0026]
[Chemical 1]

[0027]
In the said general formula (I), R1 represents a hydrogen atom or a C1-C6 lower alkyl group. L represents a C1-C20 bivalent coupling group. E represents a heterocycle containing a nitrogen atom having a double bond with a carbon atom as a constituent component, and among these, an imidazole group shown below is particularly preferable. n represents 0 or 1.
[0028]
[Chemical 2]

[0029]
Use of the cationic polymer mordant having an imidazole group is advantageous in terms of dyeability and light fastness.
[0030]
These cationic polymer mordants can be used for the image receiving layer having a porous structure containing the positively charged fine particles and the negatively charged fine particles, but in another layer, for example, the lower layer of the image receiving layer having the porous structure, It is also preferable to use it.
[0031]
Examples of the anti-fading agent include an antioxidant, an ultraviolet absorber, a metal complex, and a hardener.
[0032]
Examples of the antioxidant include chroman compounds, coumaran compounds, phenolic compounds (for example, hindered phenols), hydroquinone derivatives, hindered amine derivatives, spiroindane compounds, and compounds described in JP-A No. 61-159644. Etc.
[0033]
Examples of the ultraviolet absorber include benzotriazole compounds (US Pat. No. 3,533,794, etc.), 4-thiazolidone compounds (US Pat. No. 3,352,681 etc.), benzophenone compounds (Japanese Patent Laid-Open No. And other compounds described in JP-A-54-48535, JP-A-62-136641, JP-A-61-88256, and UV-absorbing polymers described in JP-A-62-260152. Is mentioned.
[0034]
Examples of the metal complex include U.S. Pat. Nos. 4,241,155, 4,245,018, columns 3-36, 4,254,195, columns 3-8, It is described in JP-A-62-174741, JP-A-61-88256, pages (27) to (29), JP-A-63-199248, JP-A-1-75568, JP-I-74272, and the like. And the like.
[0035]
Examples of the hardener include those described in US Pat. No. 4,678,739, column 41, JP-A-59-116655, JP-A-62-245261, JP-A-61-18942, and the like. It is done.
Specific examples of the hardener include an aldehyde hardener (formaldehyde, etc.), an aziridine hardener, an epoxy hardener, a vinyl sulfone hardener (N, N′-ethylene-bis (vinylsulfonylaceta). Mid) ethane), N-methylol hardeners (dimethylol urea, etc.), polymer hardeners (compounds described in JP-A-62-234157, etc.) and the like.
[0036]
Useful examples of the anti-fading agent are described in JP-A-62-215272, pages (125) to (137).
[0037]
Examples of the fluorescent brightening agent include K.I. Examples include compounds described in “The Chemistry of Synthetic Dies” edited by Veenkataraman, Volume V, Chapter 8, Japanese Patent Application Laid-Open No. 61-148752, and the like. Specific examples include stilbene compounds, coumarin compounds, and biphenyl compounds. Examples include compounds, benzoxazolyl compounds, naphthalimide compounds, pyrazoline compounds, carbostyryl compounds, and the like.
The fluorescent whitening agent can be used in combination with the anti-fading agent.
[0038]
In the present invention, various surfactants may be used as the additive for the purpose of coating aid, peelability improvement, smoothness improvement, antistatic, development promotion and the like.
[0039]
Specific examples of the surfactant are described in JP-A Nos. 62-173463 and 62-183457.
[0040]
In the present invention, an organic fluoro compound may be used for the purpose of improving smoothness and preventing static electricity.
Representative examples of the organic fluoro compounds include fluorine-based surfactants described in JP-B-57-9053, columns 8 to 17, JP-A-61-20944, and 62-135826. Examples thereof include hydrophobic fluorine compounds such as oily fluorine compounds such as fluorine oil or solid fluorine compound resins such as tetrafluoroethylene resin.
[0041]
Further, in the present invention, a matting agent may be used. Examples of the matting agent include compounds such as benzoguanamine resin beads, polycarbonate resin beads, and AS resin beads in addition to the compounds described in JP-A-61-88256 (page 29) such as silicon dioxide, polyolefin, and polymethacrylate. Examples thereof include compounds described in JP-A Nos. 63-274944 and 63-274952.
[0042]
The image receiving layer has a porous structure, and whether or not the image receiving layer has a porous structure can be determined by, for example, using a mercury porosimeter (pore sizer 9320-PC2, manufactured by Shimadzu Corporation) with a porosity. It can confirm by measuring.
[0043]
The porosity of the image-receiving layer varies depending on the primary particle diameter of the positively charged fine particles and the negatively charged fine particles, the amount of the aqueous binder, etc., but cannot be generally defined, but is 40 to 80%. Is preferable, and it is more preferable that it is 45 to 70%.
If the porosity is less than 40%, the ink absorption rate may not be sufficient, and if it exceeds 80%, cracking or the like tends to occur.
[0044]
The image receiving layer may have a single layer structure or a laminated structure.
The thickness of the image receiving layer preferably has an absorption capacity sufficient to absorb all ink droplets, and more specifically, it is preferably determined in relation to the porosity of the coating film. For example, when the ink amount is 8 nl / mm 2, the thickness is preferably about 15 μm or more if the porosity is 60%. The thickness of the image receiving layer is preferably 5 to 50 μm. If the thickness of the image receiving layer exceeds 50 μm, cracking may occur and curling may increase, and if it is less than 5 μm, the ink absorbability may be poor and dye bleeding may occur during storage.
[0045]
(Other layers)
The other layer is not particularly limited and may be appropriately selected from known ones. Examples thereof include a protective layer, a release layer, an anti-curl layer, and the like. It is preferable to have it on the surface of the material.
[0046]
The ink jet image receiving material of the present invention can be suitably produced by the following method for producing an ink jet image receiving material of the present invention.
In the method for producing an inkjet image receiving material of the present invention, an image receiving layer solution is applied onto the support and dried to form a porous image receiving layer.
[0047]
The image-receiving layer solution contains at least the positively charged fine particles, the negatively charged fine particles, and the aqueous binder, and the other components appropriately selected as necessary.
[0048]
The content of the positively charged fine particles and the negatively charged fine particles blended in the image receiving layer liquid is preferably 0.5 to 10 parts by weight, and 1 to 6 parts by weight with respect to 1 part by weight of the aqueous binder. Is more preferable.
If the content is less than 0.5 parts by weight, the image-receiving layer may not have a porous structure. If the content exceeds 10 parts by weight, the strength of the image-receiving layer decreases and cracks occur during drying. There is a risk of cracking. On the other hand, when the content is in the numerical range, there is no such thing, and it is advantageous in that an ink-jet image receiving material having high ink absorbability and quick ink drying after printing can be obtained.
[0049]
The image-receiving layer solution can be prepared, for example, as follows. That is, a predetermined amount of each of the positively charged fine particles, the negatively charged fine particles, the aqueous binder, and the other components appropriately selected can be prepared by adding to a dispersion medium and mixing, Preferably, the dispersion of the positively charged fine particles, the dispersion of the negatively charged fine particles, the aqueous solution or aqueous dispersion of the aqueous binder, and the aqueous solution or aqueous dispersion of the other components are mixed. can do.
[0050]
The dispersion medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water, alcohols such as methanol and ethanol, and aqueous media such as a mixed solution thereof.
[0051]
Uniform dispersion of the positively charged fine particles and the negatively charged fine particles in the image receiving layer liquid is, for example, 2 to 20 weights of the positively charged fine particles and the negatively charged fine particles in 100 parts by weight of the dispersion medium (for example, water). This is achieved by adding a part and fully blending in the water as the dispersion medium, and then dispersing these fine particles in water using a disperser. Further, after preparing the dispersion by separately dispersing the positively charged fine particles and the negatively charged fine particles, the dispersion of the negatively charged fine particles is added little by little while stirring the dispersion of the positively charged fine particles. It is achieved by going.
[0052]
The disperser is not particularly limited and may be appropriately selected depending on the intended purpose.For example, various mills that disperse mechanically by directly applying force, a high-speed stirring disperser having a large shearing force, Any of a disperser or the like that provides high intensity ultrasonic energy may be used. Specific examples include a ball mill, a sand grinder mill, a visco mill, a colloid mill, a homogenizer, a dissolver polytron, a homomixer, a homoblender, a ketdy mill, a jet agitator, a capillary emulsifier, a liquid siren, an electrostrictive ultrasonic wave. Examples include a generator and an emulsifier having a Ballman whistle.
[0053]
The aqueous binder may be separately prepared as an aqueous solution or an aqueous dispersion and mixed with at least one of the positively charged fine particle dispersion and the negatively charged fine particle dispersion. The aqueous binder is mixed in advance in the dispersion of the positively charged fine particles, and the dispersion of the negatively charged fine particles is added little by little while stirring this dispersion. It is preferable at the point which forms a layer.
In addition, when dispersing the positively charged fine particles and the negatively charged fine particles, a predetermined amount of the aqueous binder is added to the dispersion medium in advance, and the aqueous binder acts as a dispersion stabilizer (protective colloid). It is also preferable that
[0054]
The image-receiving layer solution prepared as described above is coated on the support to form a coating layer.
Application of the liquid for the image receiving layer can be carried out by using a known application means according to a known application method. Examples of the application means include an air doctor coater, a blade coater, a rod coater, a knife coater, a squeeze coater, Examples include reverse roll coaters and bar coaters.
[0055]
The coating layer formed by coating on the support is dried, and the liquid component (water) such as the dispersion medium is removed from the coating layer. As a result, the porous structure is formed on the support. An image receiving layer is formed, and the image receiving material for inkjet of the present invention is produced.
[0056]
As the drying conditions, the temperature is 25 to 180 ° C., and the time is about 5 to 20 minutes.
In the image-receiving layer solution, as the aqueous binder, a polymer whose aqueous solution or aqueous dispersion gels at a low temperature (for example, polyvinyl alcohol using gelatin, κ-carrageenan, boric acid or a salt thereof as a gelling agent) is used. In this case, for example, after setting at 0 to 15 ° C., it can be dried at 25 to 50 ° C. (referred to as set drying).
[0057]
During the drying, water as the dispersion medium is volatilized and removed, the aqueous binder is cured to form a film, and the positively charged fine particles and the negatively charged fine particles are partially fixed and porous. A structure is formed. Thus, by fixing these fine particles so as to have voids and forming a porous structure, the image receiving layer can be made excellent in ink absorbability, and can be used for high-quality ink jets. This is advantageous in that an image receiving material is obtained.
[0058]
As described above, in the drying, when moisture such as the dispersion medium is removed, the interaction between the positively charged fine particles and the negatively charged fine particles becomes strong, and these are electrically attracted to each other. In addition, the image-receiving layer having a porous structure is formed that is fixed in a bead-like pattern alternately so as to be electrically stable and has excellent strength, high porosity, and uniform pores. . At this time, since the use amount of the negatively charged fine particles is smaller than that of the positively charged fine particles, the image receiving layer is in a positively charged state as a whole.
[0059]
According to the method for producing an inkjet image receiving material of the present invention, the image receiving layer having a porous structure having a large three-dimensional void can be easily obtained by the interaction between the positively charged fine particles and the negatively charged fine particles without performing any special treatment. In addition, since the image receiving layer has a surface charge excellent in acceptability of the coloring material contained in the ink, a high quality image receiving material for inkjet can be produced.
[0060]
【Example】
  Examples of the present invention will be described below, but the present invention is not limited to these examples.
(referenceExample 1)
<Preparation of image-receiving layer solution>
  An image-receiving layer solution having the following composition was prepared.
-Composition of image-receiving layer solution-
    Polyvinyl alcohol ... 10 parts by weight
      (Kuraray Co., Ltd., PVA420)
    Barium sulfate ultrafine particles (plus charged fine particles) ... 40 parts by weight
      (Manufactured by Sakai Chemical Industry Co., Ltd., Varifine BF20)
    Silica ultrafine particles (negatively charged fine particles) ... 1.2 parts by weight
      (Aerosil 200 manufactured by Aerosil)
    Water ... 300 parts by weight
  That is, 40 parts by weight of barium sulfate ultrafine particles and 1.2 parts by weight of silica ultrafine particles were added to water (160 parts by weight), and using a high-speed rotating colloid mill (CLEAMIX, manufactured by M Technique Co., Ltd.) After dispersion at 10,000 rpm for 20 minutes, an aqueous polyvinyl alcohol solution (in which 10 parts by weight of polyvinyl alcohol is dissolved in 140 parts by weight of the remaining water) is added and dispersed under the same conditions as above for the image receiving layer A liquid was prepared.
[0061]
The image-receiving layer solution was applied onto a biaxially stretched polyethylene terephthalate film having a thickness of 100 μm and subjected to corona discharge treatment on both sides, using an air knife coater, and 70 ° C. (wind speed 5 m / second) using a hot air dryer. ) For 10 minutes. As a result, an image receiving layer having a thickness of 15 μm after drying was formed to obtain an image receiving material for inkjet.
When the porosity of the image receiving layer was measured using a mercury porosimeter (pore sizer 9320-PC2, manufactured by Shimadzu Corporation), it was 53%.
[0062]
(Example 2)
  After adding 800 g of barium sulfate ultrafine particles (positively charged fine particles, Varifine BF20, primary particle size 0.05 μm) to 3200 g of water and roughly dispersing, the particles are dispersed with a dynomill until the average particle size becomes 0.15 μm or less. Thus, a dispersion (20% by weight) of positively charged fine particles was obtained.
  Next, while stirring 150 parts by weight of the positively charged fine particle dispersion, 100 parts by weight of a 7% by weight polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA420) solution is added, and colloidal silica (negatively charged fine particles, Nissan Chemical Industries Co., Ltd., Snowtex C) 5 parts by weight of a 20% by weight solution was added in small amounts while stirring to prepare an image-receiving layer coating solution.
  Basis weight 100g / m sized with polyvinyl alcohol aqueous solution²The image receiving layer coating solution was applied in the same manner as in Example 1 on a polyethylene laminated paper obtained by melt extrusion coating a polyethylene layer having a thickness of 30 μm on the backside of the base paper and a polyethylene layer containing 10% by weight of titanium dioxide on the surface. An image receiving material for inkjet was obtained.
  The porosity of the image receiving layerreferenceWhen measured in the same manner as in Example 1, it was 65%.
[0063]
(referenceExample 3)
  Example2In Example, except that the barium sulfate dispersion was replaced with alumina (plus charged fine particles, manufactured by Nissan Chemical Industries, Ltd., AL-200).2In the same manner, an ink-jet image receiving material was produced.
  Example of porosity of image receiving layer2As a result of the measurement, it was 60%.
[0064]
(Comparative Example 1)
  referenceIn Example 1, except that silica ultrafine particles were not used,referenceIn the same manner as in Example 1, an inkjet image-receiving material was produced.
  When the porosity of the image receiving layer was measured in the same manner as in Example 1, it was 31%.
[0065]
(Comparative Example 2)
In Example 2, an inkjet image-receiving material was produced in the same manner as in Example 2 except that colloidal silica was not used.
When the porosity of the image receiving layer was measured in the same manner as in Example 2, it was 38%.
[0066]
(Comparative Example 3)
  referenceIn Example 3, except that colloidal silica was not used,referenceIn the same manner as in Example 3, an inkjet image receiving material was produced.
  The porosity of the image receiving layerreferenceWhen measured in the same manner as in Example 3, it was 40%.
[0067]
The following performance was evaluated for each inkjet image-receiving material produced as described above, and the results are shown in Table 1.
[0068]
(1) Ink absorption speed
Immediately after performing black solid printing (after about 10 seconds) on each obtained ink-jet image receiving material with an ink-jet printer (PIXEL SET, manufactured by Canon Inc.), presence or absence of transfer onto the paper Was determined as follows.
◎ ... No ink was transferred to the paper.
○: Very little ink was transferred to the paper.
Δ: A little ink was transferred to the paper.
× · · · The transfer of ink to paper was remarkable.
[0069]
(2) Image blur
Character printing was performed on each of the obtained ink-jet image receiving materials by the ink jet printer, and bleeding of the image after 2 hours of printing was evaluated. Further, this print sample was allowed to stand for 2 days under a high temperature and high humidity condition of 40 ° C. and 90% RH, and then image bleeding was evaluated.
A ... No bleeding
B ... Some blurring
C ...
[0070]
(3) Dyeing property of pigment
The obtained inkjet image-receiving material was subjected to magenta printing with the inkjet printer, dried, and then washed with water for 30 seconds. At that time, the printing density before and after washing with water was measured with a Macbeth densitometer, and the remaining ratio (%) of the dye remaining without flowing out by washing with water was calculated to evaluate the dyeing property. The larger the value, the better the dyeing property. The magenta dye used is an acidic dye having a negative charge, and the dye remaining rate increases when the surface of the image receiving layer in the ink jet image receiving material has more positively charged fine particles. The presence state of fine particles can be detected.
[0071]
[Table 1]

[0072]
  Based on the results shown in Table 1, implementationExample 2The image receiving layer of the ink jet image receiving material had a high porosity, an excellent ink absorption rate, no bleeding of images, and excellent properties. On the other hand, Comparative Example 1 containing no negatively charged fine particles~ 3Inkjet image receiving materialExample 2Compared with the ink-jet image receiving material, the porosity was low, the ink absorption rate was slow, and the image bleeding was observed to be negligible.
[0073]
【The invention's effect】
According to the present invention, it is possible to provide an ink jet image receiving material having high ink absorbability and excellent dyeing property, and a method for easily producing the ink jet image receiving material.

Claims (3)

A colloidal comprising an image-receiving layer on a support, the image-receiving layer having an average particle size of 0.3 μm or less and positively charged barium sulfate fine particles on the surface, and an average particle size of 0.3 μm or less An ink jet image receiving material having a porous structure comprising 0.1 to 20 parts by weight of colloidal silica fine particles with respect to 100 parts by weight of fine particles of barium sulfate having a positive charge on the surface . An image-receiving layer containing, on a support, fine particles of barium sulfate having an average particle size of 0.3 μm or less and having a positive charge on the surface, colloidal silica particles having an average particle size of 0.3 μm or less, and an aqueous binder. A coating solution is applied and dried to form a porous image-receiving layer containing 0.1 to 20 parts by weight of colloidal silica fine particles for 100 parts by weight of positively charged barium sulfate fine particles on the surface. A method for producing an inkjet image-receiving material. The method for producing an image receiving material for inkjet according to claim 2 , wherein the aqueous binder is polyvinyl alcohol.