JP4208503B2 - Image robustness improvement method - Google Patents

Description

【００２６】
【化２】

【００２７】
上記式中、ｔ−Ｃ₄Ｈ₉はｔｅｒｔ−ブチル基を、ｔ−Ｃ₈Ｈ₁₇はｔｅｒｔ−オクチル基をそれぞれ表す。
【００２８】
Ｂ：被記録媒体
本発明に用い得る被記録媒体としては、多孔質層のインク受容層を有し、インクが付着することで記録を行う被記録媒体であればいずれのものでも使用することができる。しかし、本発明では被記録媒体に画像堅牢性向上剤を含浸させるため、画像堅牢性向上剤が裏抜けしない媒体であることが好ましい。本発明にかかる被記録媒体は、特に、インク受容層の多孔質構造が微粒子から形成され、且つ、該微粒子に色材が吸着するような被記録媒体がインクジェット法を利用する場合に特に好適である。このようなインクジェット用の被記録媒体としては支持体上のインク受容層に形成された間隙によりインクを吸収するいわゆる吸収タイプであることが好ましい。吸収タイプのインク受容層は、微粒子を主体とし、必要に応じて、バインダーやその他の添加剤を含有する多孔質構造を有する。
【００２９】
微粒子の例としては、シリカ、クレー、タルク、炭酸カルシウム、カオリン、アルミナあるいはアルミナ水和物等の酸化アルミニウム、珪藻土、酸化チタン、ハイドロタルサイト、酸化亜鉛等の無機顔料や尿素ホルマリン樹脂、エチレン樹脂、スチレン樹脂等の有機顔料が挙げられ、これらの１種以上が使用される。バインダーとして好適に使用されているものには水溶性高分子やラテックスを挙げることができる。例えば、ポリビニルアルコールまたはその変性体、澱粉またはその変性体、ゼラチンまたはその変性体、アラビアゴム、カルボキシメチルセルロース、ヒドロキシエチルセルロース、ヒドロキシプロピルメチルセルロースなどのセルロース誘導体、ＳＢＲラテックス、ＮＢＲラテックス、メチルメタクリレート−ブタジエン共重合体ラテックス、官能基変性重合体ラテックス、エチレン酢酸ビニル共重合体などのビニル系共重合体ラテックス、ポリビニルピロリドン、無水マレイン酸またはその共重合体、アクリル酸エステル共重合体などが使用され、これらから選択した１種、あるいは必要に応じて２種以上を組み合せて用いることができる。
【００３０】
インク受容層には、その他の添加剤を使用することもでき、例えば、必要に応じて分散剤、増粘剤、ｐＨ調整剤、潤滑剤、流動性変性剤、界面活性剤、消泡剤、離型剤、蛍光増白剤、紫外線吸収剤、酸化防止剤などを挙げることができる。
【００３１】
本発明にかかる特に好適な被記録媒体は、上述の微粒子として、平均粒子径が１μｍ以下の微粒子を主体として、インク受容層を形成したものが好ましい。上記の微粒子として、特に好ましいものは、例えばシリカまたは酸化アルミニウム微粒子等が挙げられる。酸化アルミニウム微粒子、シリカにおいて特に効果的な理由としては以下の様に考えられる。即ち、酸化アルミニウム微粒子、シリカに吸着された色材は、ＮＯ_X、ＳＯ_X、オゾン等のガスによる色材の褪色を受け易いことが判ったが、これらの微粒子はガスを引き寄せやすく、色材の近傍にガスが存在することになり色材が褪色し易くなるためと思われる。シリカ微粒子として好ましいものは、コロイダルシリカに代表されるシリカ微粒子である。コロイダルシリカ自体も市場より入手可能なものであるが、特に好ましいものとして、例えば特許第２８０３１３４号、同２８８１８４７号公報に掲載されたものを挙げることができる。酸化アルミ微粒子として好ましいものとしては、アルミナ水和物微粒子を挙げることができる。このようなアルミナ系顔料の一つとして下記式により表されるアルミナ水和物を好適なものとして挙げることができる。
【００３２】
Ａｌ₂Ｏ_3-n（ＯＨ）_2n・_mＨ₂Ｏ
上記式中、ｎは１、２または３の整数のいずれかを表し、ｍは０〜１０、好ましくは０〜５の値を表す。但し、ｍとｎは同時には０にはならない。ｍＨ₂Ｏは、多くの場合ｍＨ₂Ｏ結晶格子の形成に関与しない脱離可能な水相をも表すものである為、ｍは整数または整数でない値を取ることもできる。またこの種の材料を加熱するとｍは０の値に達することがありうる。
【００３３】
アルミナ水和物は一般的には、米国特許第４２４２２７１号、米国特許第４２０２８７０号に記載されているようなアルミニウムアルコキシドの加水分解やアルミン酸ナトリウムの加水分解のような、また特公昭５７−４４６０５号公報に記載されているアルミン酸ナトリウム等の水溶液に硫酸ナトリウム、塩化アルミニウム等の水溶液を加えて中和を行う方法などの公知の方法で製造されたものを使用したものが好適である。
【００３４】
更に、これらのアルミナ水和物を使用したインクジェット用被記録媒体は、本発明にかかる画像堅牢性向上剤との親和性、吸収性、定着性が優れる上、前述したような写真画質を実現するために必要とされる光沢、透明性および染料等の記録液中の色材の定着性等が優れていることより、本発明を適用するのに更に好適である。
【００３５】
本発明に用いられるインクジェット用被記録媒体の微粒子と前記のバインダーの混合比は、重量比で、１：１〜１００：１の範囲にあることが好ましい。バインダーの量を上記範囲とすることで、インク受容層への画像堅牢性向上剤の含浸に好適な細孔容積の維持が可能となる。酸化アルミニウム微粒子またはシリカ微粒子のインク受容層中の好ましい含有量としては、５０重量％以上、より好ましくは７０重量％以上、更に好ましくは、８０重量％以上であり、９９重量％以下であることが最も好適である。インク受容層の塗工量としては、画像堅牢性向上剤の含浸性を良好とするために乾燥固形分換算で１０ｇ／ｍ²以上であることが好ましく、１０〜６０ｇ／ｍ²が最も好適である。
【００３６】
本発明に用いられる被記録媒体は上記したインク受容層を支持するための支持体を有することが好ましいが、支持体としては、特段の制限がなく、上記した多孔質構造のインク受容層の形成が可能であって、且つインクジェットプリンタ等の搬送機構によって搬送可能な剛度を与えるものであれば、いずれのものでも使用できる。例えば、支持体とインク受容層の間に硫酸バリウム、酸化チタン、酸化亜鉛等の無機顔料等をバインダーと共に塗工して形成した多孔質層を有するものや、支持体にレジンコート紙を用いても良い。そして、上記支持体とインク受容層の間に多孔質層を有する被記録媒体は、前記した本発明のより好ましい態様である、「画像形成領域が、インク受容層の厚さ方向に存在する孔部の全てあるいは実質的に全てが向上剤によって充填されている部分を有する記録物」に用いられた場合により効果がある。つまり、インク受容層の厚さ方向に存在する孔部の全てあるいは実質的に全てが向上剤によって充填されている記録物を、高温・高湿環境下に長時間放置したような場合であっても、記録物表面への向上剤の染み出しなどによる表面のべたつきなどが生じることを極めて有効に抑制でき、保管性においても極めて優れた記録物とすることができる。
【００３７】
上記したような効果が得られる理由は明らかでないが、インク受容層の厚さ方向に存在する孔部の全てあるいは実質的に全てを充填するために供給された画像堅牢性向上剤は透気度の低い、例えば、バライタ層を通り抜け難い為、画像堅牢性向上剤による孔部の充填が確実に行われ、さらにまた、インク受容層中の孔部に存在している空気や水分が、図３に模式的に示した様に、堅牢性向上剤の孔部への充填処理に伴って、多孔質層（１３０１）に移行し、或いは吸着されて、インク受容層中への空気や水分の残留を抑制もしくは防止することができる為であると考えられる。
【００３８】
Ｃ：記録物の製造方法および画像堅牢性向上方法
本発明にかかる記録物とは、支持体（１０００）表面に、微粒子（１００５）を含む多孔質構造のインク受容層（１００３）を備え、該微粒子の表面に吸着した色材（１００９）により画像が形成されている領域を有する記録物であって、該領域に上記した画像堅牢性向上剤（以下、向上剤）１００１が付与されたものである。
【００３９】
そして、例えば、図２に示すよう、該画像が形成されている領域が、インク受容層の厚さ方向に分布している色材の全てまたは実質的に全てが画像堅牢性向上剤中にある部分を有する、あるいは、インク受容層の厚さ方向に分布している孔部の全てまたは実質的に全てが画像堅牢性向上剤によって充填されている態様がより好ましく、画像堅牢性はさらに向上する。また、本発明にかかる記録物のインク受容層は多孔質構造であれば、特に微粒子を含むものに限定されるものではない。
【００４０】
上記した本発明のより好ましい態様の場合に、受容層を有する被記録媒体に形成したインク等による記録物（プリント物）の色味の改善や耐ガス性の驚異的な向上が達成される理由は以下のようなメカニズムによるものと考えられる。
【００４１】
図１は、紙などからなる支持体上に微粒子からなる多孔質構造のインク受容層を備える、いわゆるコート紙の断面構造を模式的に示している。図１において、１０００は支持体、１００３は、支持体１０００に保持されているインク受容層である。インク受容層１００３は、微粒子１００５を含む多孔質構造を形成しており、微粒子は、結着剤（バインダー）１００７によって固定されている。そしてこのようなコート紙に付与されたインク滴は、インク受容層１００３に染み込んでいく過程において、インクに含まれる色材１００９が微粒子１００５の表面に吸着され、画像が形成される。
【００４２】
このようにして記録の為されたコート紙の表面に、画像堅牢性向上剤１００１を供給した後、インク受容層の比較的深部にある色材をも向上剤中にあらしめるために、例えば、インク供給後にラビング処理を行うと、画像堅牢性向上剤は、インク受容層１００３中の孔部、ここでは微粒子１００５の隙間（間隙）１０１１を充填していく。向上剤は、非水系の物質であることから、粒子間にトラップされている水性インクの水性媒体を次々と置換していき、微粒子表面に吸着している色材の周囲も被覆していく。そして、最終的に図２に示した様に、間隙１０１１が向上剤１００１で充填され、インク受容層の厚さ方向に分布している色材の全てまたは実質的に全てが画像堅牢性向上剤中にある、あるいは、インク受容層の厚さ方向に存在する孔部の全てあるいは実質的に全てを該向上剤によって充填させると、色材１００９は大気中のＳＯ_XやＮＯ_Xなどのガスあるいはそれらを含む水分との接触を断たれることとなる。その結果、インク受容層中の色材の劣化が抑制され、画像の堅牢性の向上がさらに図られるものと考えられる。また、本発明による画像の堅牢性向上効果と共に得られる色味の改善、印字濃度向上、光沢度の向上の効果は、インク受容層を形成している物質と孔部（空気）、ここでは微粒子と間隙（空気）との屈折率の差によって生じていたインク受容層表面および内部における光の乱反射が、該間隙が画像堅牢性向上剤で充填されることによって抑制される為であると考えられる。
【００４３】
本発明にかかる画像堅牢性向上剤は、好ましくは液体の状態でインク受容層に付与される。そのため、インク受容層への浸透が容易に行われ、かつインク受容層内の多孔質構造の形状に対応して変形し、画像堅牢性向上剤中への色材の取り込み効果を十分に発揮することが可能である。しかも、液体としてインク受容層内に保持されることで、記録物に許容できる変形を生じさせた場合において、インク受容層の多孔質構造、例えば間隙の内壁や微粒子が含有されている場合における微粒子の外壁との画像堅牢性向上剤の接触状態が良好に維持される。
【００４４】
一方、画像堅牢性向上剤を、ワックスなどの通温において固形状態の形態とした場合は、インク受容層への浸透に圧力を必要としたり、均一な浸透状態が得られ難いなどがある。更に、揮発性溶剤により希釈された状態で適用され、適用後に固化するもの、あるいは液体で適用された後に固化する成分を含むものなどの形態とした場合は、固化する過程で水分や気泡の取り込みによる向上剤の相の白濁化が生じる場合があり、更に、固化する際の体積減少が生じた場合には、向上剤の相と多孔質構造との間に空隙が生じ、色材の保護機能が減少するおそれがある。インク受容層の局所的な熱分析等の方法により、物質溶解時の熱挙動（吸熱、発熱）がないことを確認することによって、インク受容層中に液体状態で保持されていることを確認することが可能である。
【００４５】
本発明で用いる、ラビング処理とは、堅牢性向上剤をインク受容層中の孔部に積極的に充填させるための拭き取りおよび研磨の少なくとも一方の処理を示す。
【００４６】
（１）第１の実施態様
本発明にかかる記録物の製造方法あるいは画像堅牢性向上方法の一実施態様としては、上記したように、多孔質構造のインク受容層を備え、該インク受容層へのインク或いはインク滴の付与によって、文字や絵等の画像が記録されている記録シートの、該インク受容層表面に、前記した画像堅牢性向上剤を供給し、その後にラビング処理を行う方法が挙げられる。ここで、向上剤は、記録シートの画像記録部分の少なくとも一部にのみ供給し、塗り込んでもよいが、記録シートの全面に塗りこむことが最も好ましい。これによってインク受容層中の色材が、オゾン等のガスによって攻撃されることをより確実に抑制することができる。
【００４７】
また、前記したように、本発明のより好ましい態様は、インク受容層の厚さ方向に存在する孔部の全て或いは実質的に全てが画像堅牢性向上剤で充填されているものである。この場合、画像堅牢性向上剤の供給量は、塗りこみの手間等を考慮すると、孔部が完全に充填される量と、塗布部材への吸収分などを考慮した量とするのが適当である。ここで、孔部が完全に充填される量とは、例えば、微粒子からなるインク受容層の場合はインク受容層の間隙度（吸油量など）などから考慮する。このような量の画像堅牢性向上剤を供給し、塗り込むことで、インク受容層の孔部をほぼ確実に画像堅牢性向上剤で充填することができる。
【００４８】
具体的には、例えば、吸油量が０．３ｃｃである記録媒体に形成されてなる画像の堅牢性を向上させる為には、約０．３ｇ程度の画像堅牢性向上剤を付与し、ラビング処理することで十分な堅牢性の向上効果を得ることができる。このことは、インク受容層の表面部分を覆うだけではなく、画像堅牢性向上剤がインク受容層の孔部を充填することによって、本発明の効果が達成されるものであることを表すものである。
【００４９】
ここで該画像堅牢性向上剤の塗布方法については、刷毛塗り、スプレー塗り、ローラー塗り、へら塗り、スポンジ塗布等特に制限されないが、具体的な方法として、例えば、図５に示した様に、適当量の画像堅牢性向上剤をインク受容層表面に一定量を供給可能な機能５００１（スプレーやポンプなど）を備えた容器５００３（ディスペンサー等）に該向上化剤を含むものとラビング用の部材とがセットとなった画像堅牢性向上化キットを用いることで実現可能である。
【００５０】
また他の実施態様としては、図４（ａ）及び（ｂ）に示した様な、画像堅牢性向上剤を含んでいる画像堅牢性向上化剤貯蔵部４００１と、画像堅牢性向上剤の塗布部材４００２とが一体化され、該貯蔵部内の画像堅牢性向上剤が該塗布部材表面に滲出可能に構成されているアプリケータを用いて、画像堅牢性向上剤の供給とラビング処理とを同時に行うようにしてもよい。尚、塗布部材４００２の画像堅牢性向上剤が少なくなってきた場合に、画像堅牢性向上化剤貯蔵部４００１に圧力をかけることにより、塗布部材に画像堅牢性向上剤がしみ込むような構成であっても良い。４００３は４００２の蓋である。本発明にかかる方法で画像堅牢性に優れた記録物を得るために、上記被記媒体と上記画像記録性向上剤とのセットを用いることで、簡便に堅牢性の高い画像をえることができる。
【００５１】
（２）他の実施態様
本発明にかかる記録物の製造方法あるいは画像堅牢性向上方法の他の実施態様として、記録装置内で人手を介在させること無しに処理する方法を挙げることができる。図６は、画像堅牢性に優れた記録物を得るための装置の概略断面図であり、インクジェット法による記録媒体への画像の記録と、形成された画像への堅牢性付与の処理とを行う手段を各々備えている。図６において、２５は筐体であり、１は積層された未使用の記録媒体で、サプライトレイ（給紙用カセット）２に略水平に載置されている。
【００５２】
３は吸盤で、吸盤移動機構（不図示）により、図中ａの位置から積層された未使用の記録紙１の最上部の１枚に接する位置ｂに移動し、最上位の用紙を吸引して持ち上げることができる。この際、吸引機構（不図示）により、吸盤３が記録紙に接した状態で吸盤３の内部の圧力を減少させて記録紙１の最上部の１枚を吸着して、その記録紙を他の記録紙から分離させる。その状態で吸盤移動機構により図中ｃの位置に移動し、その分離した１枚の記録紙の先端を搬送ローラ４，５の間に差し込むことができる。その後、吸引機構による吸引動作を停止させて吸盤３の吸着力を解除し、吸盤３による記録紙の拘束を解くことができる。
【００５３】
搬送用ローラ４，５は、搬送用モータ（不図示）等の駆動源によりクラッチ機構（不図示）等を介して回転駆動される。６，７はガイド板で、所定の間隔を持って対向して配置されており、搬送用ローラ４，５の回転により搬送される記録紙の供給経路を形成している。これらガイド板６，７で形成される供給経路の断面形状は略半円形であり、搬送用ローラ４，５近傍から上方の副走査用ローラ８，９に至っている。これら副走査用ローラ８，９は、図中左方向に平行に配置された第２の副走査用ローラ対１０，１１と共に、搬送されてきた記録紙を挟持し、後述する制御部（不図示）などの制御の下に紙送りを行っている。１５は副走査用ローラ８，９，１０，１１の間での記録紙の位置を規制するガイド板である。１２は記録ヘッド（インクジェットヘッド）で、記録紙１の搬送方向に複数のインク吐出用ノズルが配されている。尚、この記録ヘッド１２は、それぞれが異なる色のインクを吐出する複数のインクジェットヘッドを備えていても良い。１３は記録ヘッド１２に供給するインクを収容しているインクタンクである。記録ヘッド１２とインクタンク１３はキャリッジに載置されており、副走査用ローラ８〜１１の回転軸と略平行に配置されたキャリッジガイドにより、記録紙の搬送方向に略直交する方向に移動可能に保持されている。
【００５４】
１６は、上方の記録紙収容部に積層して収容された未使用の第２の記録紙である。１７は積層収納された記録紙１６を載置し、分離ローラ１８方向に適宜押圧する圧板である。１９，２０はガイド板で、分離ローラ１８により取り出された１枚の記録紙の先端を副走査用ローラ８，９に導くための第２の供給経路を形成している。
【００５５】
２１，２２，２３，２４は、例えば特開平１−２６４８７９号公報で開示されている各記録紙１，１６の有無及びその紙質を検知する手段である。２１，２３はそれぞれ記録紙１，１６の表面に所定波長の光を照射する光源、２２，２４は、その光源から照射された光が記録紙表面から反射された光を受光する光検出器である。
【００５６】
このような反射光による記録紙の紙質の検知は、記録紙の種類に応じて表面の粗さが異なり、それに伴って光の拡散の程度が異なってくることに起因してなされるものである。例えば普通紙の表面は微視的にみれば繊維の絡み合ったもので表面の拡散は大きく、従って検出器２２，２４の出力は小さくなる。一方、表面が平滑で、光の拡散の程度の低いシートの場合、検出器２２，２４の出力が大きくなる。このような光による検出手段を用いて、吸盤３を使用した第１の分離機構、或は分離ローラ１８を使用した第２の分離機構に対応する記録紙がそれぞれ対応するカセットに装填されているか、又は記録に適した記録紙が装着されているかなどが判断可能となる。
【００５７】
２６，２７は記録ヘッド１２による記録終了後、副走査ローラ１０，１１の回転に伴って排出される記録紙を後述の工程に導くための搬送路を形成するガイド板である。ガイド板には面状のヒータ（不図示）が取り付けられており、ガイド板２６，２７で形成された搬送路内の記録紙を加熱し、その記録紙上に吐出されたインクの乾燥を促進する。
【００５８】
こうして得られた記録物の記録面に対して、画像堅牢性向上剤を供給し、該記録物のインク受容層に、画像堅牢性向上剤が充填された領域を形成する。
【００５９】
液体５２は、本発明にかかる画像堅牢性向上剤であり、容器５１に不図示のタンクから不図示の供給装置にて供給され、常に容器５１内における液面の高さが所定の範囲内になるように自動的に供給・制御されている。５３は堅牢性向上剤塗布用ローラで、その表面部５３ａは堅牢性向上剤５２が浸透可能なスポンジ状の構造となっており、その一部が容器５１内の堅牢性向上剤５２に接していて、液体塗布用ローラ５３が不図示の駆動源の駆動により回転することにより、その表面部５３ａに一様に堅牢性向上剤５２を浸潤させることができる。５４は塗布用ローラ５３との協動により記録媒体を挟持して搬送する搬送用ローラである。尚、この搬送用ローラ５４は、その表面に堅牢性向上剤５２が付着しないように、記録媒体が挟持されていない時は塗布用ローラ５３と離間し、記録媒体が介在している場合にのみ塗布用ローラ５３と搬送用ローラ５４と接触して記録媒体を挟持するのが望ましい。５５は乾燥用ヒータで、堅牢性向上剤５２が塗布された記録紙を乾燥させるのに使用される。
【００６０】
以上の構成により、記録ヘッド１２による記録が終了した後、その記録紙の後端が第２の副走査ローラ対１０，１１から離れる以前に記録媒体の先端が搬送用ローラ５４，塗布用ローラ５３の位置にまで到達する。そして、搬送用ローラ５４と塗布用ローラ５３との間に記録媒体が挟持され、これらローラ５３，５４の回転に伴って記録媒体の片方の面に堅牢性向上剤５２が一様に供給され、またラビングされて、インク受容層の間隙に充填される。この液体が充填された記録紙は、必要に応じて更なるラビング処理を施した後、排紙用ローラ３３の回転により３４の排紙口から装置外に排出される。
【００６１】
なお、図６では、インクジェット記録と画像堅牢性向上剤の充填とが、同一の装置内で処理される形態の画像記録装置を説明したが、これに限定されず、画像記録部と堅牢性向上液の充填部とを分離した構成の画像記録装置、更には、堅牢性向上液の充填部を、画像形成部と独立させた、画像堅牢性向上液の塗布装置もまた、本発明の範囲内のものである。
【００６２】
【実施例】
以下、実施例および比較例により本発明を更に説明する。
（画像堅牢性向上剤の調製）
下記に示す飽和脂肪酸エステルと、添加剤すなわち紫外線吸収剤を表２に示した割合で混合することによって実施例１〜６の画像堅牢性向上剤を用意した。
グループＡ． 飽和脂肪酸グリセリド
Ａ−１．化合物名：カプリン酸トリグリセリド
分子量 ４９１
【００６３】
【化３】

【００６４】
Ａ−２．化合物名：トリ２−エチルヘキサン酸グリセリル
分子量 ４７１
【００６５】
【化４】

【００６６】
Ａ−３．化合物名：トリイソステアリン酸グリセリド
分子量 ８９０
【００６７】
【化５】

【００６８】
グループＢ：添加剤
Ｂ−１．商品名：アデカスタブＬＡ−６３Ｐ（旭電化株式会社製）
【００６９】
【化６】

【００７０】
比較例１〜２
比較例１は、画像堅牢性向上化剤を用いない場合である。
比較例２は、Ｃ−１．アクリル樹脂溶液アクリル樹脂系エマルジョン商品名：ボンコート４００１大日本インキ化学工業株式会社製を用いた場合である。
【００７１】
（被記録媒体の製造例）
先ず、下記のようにして基材を作製した。濾水度４５０ｍｌＣＳＦ（Ｃａｎａｄｉａｎ Ｓｔａｎｄａｒａｄ Ｆｒｅｅｎｅｓｓ）の、広葉樹晒しクラフトパルプ（ＬＢＰＫ）８０質量部、濾水度４８０ｍｌＣＳＦの、針葉樹晒しクラフトパルプ（ＮＢＰＫ）２０質量部からなるパルプスラリーに、カチオン化澱粉０．６０質量部、重質炭酸カルシウム１０質量部、軽質炭酸カルシウム１５質量部、アルキルケテンダイマー０．１０質量部、カチオン性ポリアクリルアミド０．０３質量部、硫酸バンド０．４０質量部を添加して紙料を調整後、長網抄紙紙で抄造し、３段のウエットプレスを行って、多筒式ドライヤーで乾燥した。その後、サイズプレス装置で、酸化澱粉水溶液を固形分で１．０ｇ／ｍ²となるように含浸し、乾燥後、マシンカレンダー仕上げをし、坪量１５５ｇ／ｍ²、ステキヒトサイズ度１００秒、透気度５０秒、ベック平滑度３０秒、ガーレー剛度１１．０ｍＮの基材を得た。
【００７２】
次に、上記で得た基材上に、以下のようにして下塗り層を形成した。先ず、下塗り層の形成に使用する塗工液として、カオリン（ウルトラホワイト９０、Ｅｎｇｅｌｈａｒｄ社製）／酸化亜鉛／水酸化アルミニウムの、重量比６５／１０／２５からなる填量１００質量部と、市販のポリアクリル酸系分散剤０．１質量部とからなる固形分濃度７０％のスラリーに、市販のスチレン−ブタジエン系ラテックス７質量部を添加して、固形分６０％になるように調整して組成物を得た。次に、この組成物を、乾燥塗工量が１５ｇ／ｍ²になるように、ブレードコータで、基材の両面に塗工し、乾燥した。その後、マシンカレンダー仕上げをし（線圧１５０ｋｇｆ／ｃｍ）、坪量１８５ｇ／ｍ²、ステキヒトサイズ度３００秒、透気度３，０００秒、ベック平滑度２００秒、ガーレー剛度１１．５ｍＮの下塗り層付き基材を得た。下塗り層付き基材の白色度は、断裁されたＡ４サイズ５枚のサンプルに対して各々測定し、その平均値として求めた。その結果、Ｌ：９５、ａ^*：０、ｂ^*：−２であった（ＪＩＳ Ｚ ８７２９の色相として求めた）。
【００７３】
次に、インク受容層を形成したが、上記の第二の表面処理工程での塗工後、即ち、塗工液が下塗り層に含浸されてすぐに、そのまま下塗り層上にインク受容層を形成した。その際の、インク受容層の形成に用いた塗工液及び塗工方法等は、以下の通りである。
【００７４】
塩化アルミニウムの４重量％溶液中にアルミン酸ソーダを加えｐＨを４に調整した。その後、攪拌をしながら９０℃まで昇温し、しばらく攪拌を行った。その後、再びアルミン酸ソーダを加えてｐＨを１０に調整し、その温度を保持しながら４０時間熟成反応を行った。その後、室温に戻し、ｐＨを７〜８に調整した。この分散液に対して脱塩処理を行い、その後酢酸により解膠処理を行ってコロイダルゾルを得た。このアルミナ水和物のコロイダルゾルを濃縮して１７重量％の溶液を得た。ポリビニルアルコール ＰＶＡ１１７（商品名：クラレ社製）を純水に溶解して９重量％の溶液を得た。上記アルミナ水和物のコロイダルゾルとポリビニルアルコール溶液を、アルミナ水和物固形分とポリビニルアルコール固形分が重量比で１０：１になるように混合攪拌して、分散液を得た。これをダイコータで乾燥塗工量で３５ｇ／ｍ²になるように毎分３０ｍで塗工した。そして、１７０℃で乾燥してインク受容層を形成した。この被記録媒体のインク受容層表面にリウエットキャストコーターを用いて、熱湯を用いたリウエットキャスト処理を行い被記録媒体を得た。被記録媒体の吸油量は約２１ｃｃ／ｍ²であった。
【００７５】
上記で作成した被記録媒体に、下記の方法で画像を記録した記録物を作成し、その記録物に対して、実施例１、参考例 1 〜５の画像堅牢性向上化剤及び比較例２の化合物を用いて、下記の方法１〜５に従って各種の画像堅牢性試験を行った。また、何も処理しなかった記録物を比較例１として同様に評価を行った。
【００７６】
インクジェット方式を用いたフォト用プリンタ（商品名：ＢＪ−Ｆ８７０キヤノン製）に当該プリンタに純正のインクタンク（商品名：ＢＣＩ−６ＢＫ、ＢＣＩ−６Ｙ、Ｍ、Ｃ、ＢＣＩ−６ＰＭ、ＢＣＩ−６ＰＣ）を装着し、上記で得た被記録媒体の記録面に、単色として、ブラック、シアン、マゼンタ及びイエロー、コンポジットカラーとして、コンポジットブラック、葉緑色、肌色および空色の各色について、１００％、８０％、６０％、４０％、２０％及び１０％の各濃度のベタパッチを印字して記録物を作成した。なお、印字に用いたインクは、上記プリンタ純正品であって、全て水溶性染料を含んでいる水性インクである。次いで、この記録物のインク受容層表面に、１２６ｍｍ×８９ｍｍの面積あたり約０．３ｇの割合で、上述した種々の画像堅牢性向上剤、及び比較例１〜２の化合物を付与し、天然コットン素材のラビング部材で画像全面に亘ってラビング処理を行って、実施例１、参考例１〜５及び比較例１〜２の記録物を得た。そして各記録物について、各色Ｏ．Ｄが約１．０のパッチを選んで、以下の画像堅牢性試験に用いた。
【００７７】
耐光性および耐ガス性の評価方法：上記の記録物の試験前の画像濃度と試験後の画像濃度とを分光光度計・スペクトリノ（グレタグマクベス社製）を用いて測定した。耐光性および耐ガス性評価は、以下に記述する判定基準に基づき判定し、結果は表１に示した。
【００７８】
（試験方法）
１．耐光性試験１
以下の試験条件に従って、キセノンフェードメーターを用いて、耐光暴露試験を行った。本試験は、室内における窓越し太陽光の影響を考慮した画像堅牢性試験である。
試験条件；
照射光量：５０ｋｌｕｘ
試験時間：１００時間
試験槽内温湿度条件：３０℃・４５％ＲＨ
フィルタ：（アウター）ソーダライム、（インナー）ボロシリケート
耐光性評価：
ＩＳＯ１０９７７（１９９３）の基準を参考に耐光暴露試験後の反射濃度残存率（ΔＥ）データより評価した。具体的には、単色のインクによる記録部に関しては、試験後の記録部が示す反射濃度残存率を測定し、下記表１の基準に従って評価した。一方、複数色のインクを重ねて形成したコンポジットカラーの記録部に関しては、試験後の各記録部の反射濃度残存率に加えて、各コンポジットカラー記録部を構成している複数の構成色それぞれの耐光暴露試験後の反射濃度残存率を測定し、得られた反射濃度残存率の差を算出し、表１に示す基準に従って評価した。コンポジットカラー記録部の評価に、該コンポジットカラー記録部を構成する構成色の反射濃度残存率の差を加えた理由は、コンポジットカラー記録部の画像堅牢性は記録部自体の反射濃度残存率だけでなく、コンポジットカラー記録部を構成している複数の構成色のそれぞれの褪色の程度も視覚上の画質に大きな影響を及ぼすからである。つまり、例えコンポジットカラーの記録部自体の反射濃度残存率が大きい場合であっても、コンポジットカラーを構成している構成色の何れか１つでも、試験前後で反射濃度が大きく変化している場合には、目視におけるカラーバランスが崩れ、視覚的に退色が大きい様に感じることがある為である。
【００７９】
表１において、例えば、濃度残存率が９０％以上というのは、ブラック、シアン、マゼンタ、イエロー、コンポジットブラック、葉緑色、肌色および空色の各記録部の反射濃度残存率の内、最も低い値でも９０％以上であることを示す。また、例えば、濃度残存率の差が５％未満というのは、上記した４色のコンポジットカラー記録部において、各コンポジットカラー記録部を構成している構成色それぞれの試験前の反射濃度残存率の値の差のうちの最大値が、５％未満の場合である。濃度残存率の差が５％以上１０％未満というのは、該４色コンポジットカラー記録部のそれぞれを構成している構成色それぞれの反射濃度残存率の差のうちの最大値が５％以上１０％未満の場合である。
【００８０】
【表１】

【００８１】
評価結果を表２に示す。
【００８２】
２．耐光性試験２
以下の試験条件に従って、蛍光灯耐光性試験機を用いて、耐光暴露試験を行った。本試験は、室内における蛍光灯光の影響を考慮した画像堅牢性試験である。
試験条件；
照射光量：６０ｋｌｕｘ
試験時間：４８０時間
試験層内温湿度条件：３０℃・４５％ＲＨ
フィルタ：ソーダライム
耐光性評価；
ＩＳＯ１０９７７（１９９３）の基準を参考に耐光暴露試験後の濃度残存率データより耐光性を上記１と同様の評価基準を用いて評価した。結果を表２に示す。
【００８３】
３．耐ガス性試験
オゾン試験装置（スガ試験機社製、商品名：オゾンウエザオメーター）を用いて、オゾン暴露試験を行った。
試験条件；
暴露ガス組成：Ｏ₃３ｐｐｍ
試験時間：６時間
試験層内温湿度条件：４５℃、５５％ＲＨ
耐ガス性評価；
オゾン暴露試験後の濃度残存率データを上記１の評価と同様の評価基準を用いて評価した。結果を表２に示す。
【００８４】
４．黄変試験
（試験方法および評価方法）
未印字の被記録媒体に対して、実施例１、参考例１〜５の画像堅牢性向上剤、比較例２の化合物の各々を上記と同様にして付与し、ラビング処理して実施例１、参考例１〜５、比較例２のサンプルを調製し、比較例１としての未処理のサンプルを加えて、以下の環境の中に各サンプルを放置し、試験前後の記録面の色味を比較した。結果は表2に示した。
試験条件；
試験層温湿度条件：５０℃、８０％ＲＨ
試験時間：２４０時間
【００８５】
【表２】

【００８６】
５．光沢度試験
未印字の被記録媒体に対して、新たに実施例１、参考例１〜５の各々を上記と同様に付与して、ラビング処理してサンプルを調整し、また、比較例１として未処理のサンプルを用意した。これら３サンプルを常温で２４時間保存した後の各々の光沢度をＪＩＳ−Ｚ−８７４１に規定される方法で測定した。その結果を表３に示す。
【００８７】
【表３】

【００８８】
新たに実施例１、参考例１〜５の記録物（１００％ベタパッチ）と比較例１の記録物（１００％ベタパッチ）を１で用いたサンプルと同様に調製し、常温で２４時間保存した後の、各々の画像の濃度をグレタグスペクトロイノ（グレタグマクベス製）で測定した。その結果を表４に示す。
【００８９】
【表４】

【００９０】
【発明の効果】
本発明によって、インクジェット記録画像の堅牢性が向上し、特に、インクジェット記録画像を家庭やオフィス等の通常の室内環境で展示する用途に使用しても画像の褪色を劇的に防止することができる。又、本発明は、記録画像の記録品位を低下させることなく画像堅牢性を向上することが可能である。
【図面の簡単な説明】
【図１】本発明に用いられる被記録媒体の断面構造を模式的に示す概略断面図である。
【図２】本発明にかかる画像堅牢性の向上方法の概略説明図であり、インク受容層中の間隙に向上剤が充填された状態を示す概略断面図である。
【図３】被記録媒体の支持体として、インク受容層側の表面に緻密な多孔質層があるものを用いたときの、インク受容層中の水分子の挙動の説明図である。
【図４】本発明にかかるアプリケータの一実施態様である。（ａ）は、使用時の形態を示す概略斜視図であり、（ｂ）は収納や携帯に適する、塗布部が蓋で保護された形態を示す概略斜視図である。
【図５】本発明にかかるアトマイザの概略断面図である。
【図６】本発明にかかるインクジェット記録装置の概略断面図である。
【符号の説明】
１０００ 支持体
１００１ 画像堅牢性向上剤
１００３ インク受容層
１００５ 微粒子
１００７ 結着剤
１００９ 色材
１０１１ インク受容層中の間隙
１３０１ 多孔質層
４００１ 画像堅牢性向上剤貯蔵部
４００２ 画像堅牢性向上剤塗布部
４００３ 蓋
５００１ ディスペンス手段（スプレー部）
５００３ 画像堅牢性向上化剤貯蔵部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image fastness-improving agent capable of obtaining superior gas fastness, high quality glossiness, and high image density with respect to a recorded matter in which an image is formed on an ink-receiving layer having a porous structure. The present invention relates to a recorded matter using an image fastness improving agent, a method for improving image fastness, a method for producing a recorded matter, and an image fastness improving kit including such an image fastness improving agent.
[0002]
[Prior art]
Among various image recording methods, the ink jet recording method is currently widely used, and it is expected that it will be further used in the future. Currently required image characteristics are high-quality images comparable to silver halide photographic images, specifically feathering and bleeding, high print density, excellent water fastness, light fastness, A high-quality image with gas fastness and high-quality gloss. In particular, there is a demand for maintaining high-quality images equivalent to silver salt photographic images for a long period of time, that is, excellent fastness to deterioration due to gas in the air and deterioration due to water and moisture.
[0003]
There have been many studies to improve image robustness. For example, as disclosed in JP-A-07-314882, the gas fastness of the recording medium is improved by adding an antioxidant to the porous ink receiving layer of the ink jet recording medium. Japanese Patent Laid-Open No. 09-48180 discloses a method for protecting a printed matter by coating a protective agent made of a specific resin on the printed matter with aqueous ink. Further, as disclosed in JP-A-06-301441, after recording on a recording sheet provided with a porous layer made of alumina hydrate on a substrate, the porous layer is impregnated with a curable composition. A recording method for curing and making transparent has been proposed.
[0004]
[Problems to be solved by the invention]
However, for example, the fading phenomenon that occurs when a recorded image is displayed in a room is various, such as the entire image being reddish, greenish, or the non-printing portion being yellowed. . In addition, the cause is not limited to only light, but various factors such as various gases in the air and the effects of temperature and humidity can be considered. It is sufficient to add an antioxidant to the recording medium for ink jet recording. In some cases, it was not possible to obtain high image robustness. In addition, there is a problem that the glossiness of the surface of the printed matter may not be sufficiently obtained by the method of coating the protective agent on the printed matter. Japanese Patent Application Laid-Open No. 9-48180 discloses nothing about applying a protective agent to a printed matter formed using a recording medium having an ink receiving layer having a porous structure, and the effect thereof. There is no suggestion. Furthermore, when the inorganic porous layer is impregnated with a curable composition and cured to be transparent, there is a problem that the printed surface may be transparently uneven and unevenness may occur because the curing does not proceed uniformly. there were.
[0005]
Therefore, the present inventor can impart a gas fastness superior to that of conventional recording media to an image-recorded recording medium, and at the same time, a high-quality image having a glossiness equivalent to that of a silver salt photographic image and a high image. Various methods have been studied for obtaining the concentration. As a result, it has been found that by adding a triglyceride of a saturated fatty acid having a molecular weight of 300 or more, the fastness of an image, in particular, the fastness to gas is drastically improved, and the present invention has been achieved.
[0006]
[Means for Solving the Problems]
The image fastness improving agent for recorded matter according to the present invention is an image fastness improving agent for recorded matter having an ink receiving layer having a porous structure and having an image formed on the ink receiving layer with a coloring material. And mainly containing triglycerides of saturated fatty acids having a molecular weight of 300 or more.
[0007]
The recorded matter according to the present invention is a recorded matter that includes an ink receiving layer having a porous structure, and the ink receiving layer has an area in which an image is formed of a color material. A fastness-improving agent is provided.
[0008]
  The method for improving image fastness of a recorded matter according to the present invention is as follows.An image fastness improving method for imparting an image fastness improving agent to a recorded matter in which an image is formed with a color material in a porous ink receiving layer, wherein the image fastness improving agent is composed solely of capric acid triglyceride. Rubbed after applying image fastness improver to the recorded materialIt is characterized by that.By performing the rubbing treatment, all of the holes existing in the thickness direction of the ink receiving layer can be filled with the image fastness improving agent.
[0009]
A method for producing a recorded matter according to the present invention is a method for producing a recorded matter comprising an ink receiving layer having a porous structure, and the ink receiving layer having a region in which an image is formed of a colorant,
(I) a step of applying an ink to the ink receiving layer to obtain a region where an image is formed by a color material contained in the ink;
(Ii) a step of applying an image fastness improving agent having the above-described configuration to the ink receiving layer;
It is characterized by having.
[0010]
The kit for improving image fastness of recorded matter according to the present invention comprises a recording medium having an ink-receiving layer having a porous structure and an image fastness improving agent having the above-described configuration.
[0011]
By using the image fastness improving agent of the recorded matter of the present invention, the fastness of the recorded matter having an image formed with aqueous ink or the like on a recording medium having a porous ink receiving layer such as a coated paper, particularly ozone It is possible to remarkably improve the fastness to gases such as the above, and it is possible to add more depth to the color of the image itself. Japanese Patent Laid-Open No. 56-77154 describes filling the voids of an ink jet sheet having a porous structure with a non-volatile substance. However, there is no disclosure about the specific technique according to the present invention. Absent.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the image fastness improving agent and its use according to the present invention will be described.
[0013]
A: Image fastness improver
First, the image fastness improving agent of the present invention will be described in detail.
[0014]
An image mainly containing triglycerides of saturated fatty acids having a molecular weight of 300 or more in the ink receiving layer as an image fastness improving agent after recording an image by ink jet recording or the like in a recording medium having an ink receiving layer provided on at least one side of the substrate. A recorded image is protected from various physical or chemical changes by applying a fastness improving agent, and more preferably, thereafter impregnating the porous ink receiving layer with the image fastness improving agent. High gas fastness, high-grade glossiness equivalent to a silver salt photographic image, and high image density are imparted.
[0015]
As the image fastness improving agent, those which are in a liquid state at normal temperature (15 to 30 ° C.) and normal pressure and have low volatility are preferable. The image fastness improver according to the present invention mainly contains triglycerides of saturated fatty acids having a molecular weight of 300 or more, and may further contain other substances for various purposes as long as the effects of the present invention are not impaired. . Here, “mainly contains” means that the content is the largest among the components in the image fastness improver, preferably 50% or more, more preferably 80%, more preferably Is contained 90% or more, and the image fastness-improving agent is also included in the case where it consists only of triglycerides of saturated fatty acids.
[0016]
As the saturated fatty acid, a saturated fatty acid having 5 to 18 carbon atoms can be mentioned as a preferred range.
[0017]
Since the ester compound used in the present invention has a molecular weight of 300 or more, the volatility is extremely low, and it is difficult for the improver to evaporate after being impregnated in the porous layer and to form voids in the porous layer.
[0018]
Furthermore, the molecular weight of the ester compound is preferably 2000 or less, more preferably 1000 or less in consideration of the viscosity at normal temperature and pressure.
[0019]
The saturated fatty acid triglyceride has a characteristic that the viscosity is low when the molecular weight is the same as that of a normal fatty acid ester. Therefore, even if the molecular weight of the substance is large, the viscosity is relatively low. The ink receptive layer can easily penetrate into a relatively small pore diameter region, and the gas fastness at room temperature and also in a high temperature and high humidity environment is remarkably improved.
[0020]
Specific examples of the saturated fatty acid triglyceride having a molecular weight of 300 or more include glyceryl tri-2-ethylhexanoate, capric acid triglyceride, triisostearic acid glyceride and the like.
[0021]
According to a further preferred embodiment of the present invention, it is even better for gas resistance and light resistance to contain at least one of an antioxidant or an ultraviolet absorber.
[0022]
The antioxidant is not particularly limited as long as a predetermined effect can be obtained. For example, thiourea series such as N, N-diethylthiourea, thiuram series such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-methyl- Thiazoles such as 5-chlorobenzothiazole, 2-methyl-5-bromobenzothiazole, 2-mercaptobenzothiazole, 1,2,2,6,6-pentamethyl-4-piperidyl 1,2,3,4-butane Hindered amines such as tetracarboxylate, 1,2,2,6,6-pentamethyl-4-tridecyl1,2,3,4-butanetetracarboxylate, 2- (2H-benzotriazol-2-yl) -p -Benzotriazoles such as cresol, O, O'-dioctadecylpentaerythritol bi Phosphites such as phosphite, trisnonylphenyl phosphite, phenyl diisodecyl phosphite, dithiocarbamate such as zinc diethyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, etc., and at least one of these Seeds can be used.
[0023]
The ultraviolet absorber is not particularly limited as long as a predetermined effect can be obtained. For example, 6,6′-di-t-butyl-4,4′-butylidene di-m-cresol, 3,3 ′, Hindered phenols such as 3 ″, 5,5 ′, 5 ″ -hexa-t-butyl-α, α ′, α ″-(mesitylene-2,4,6-triyl) tri-p-cresol 2- (3,5-di-t-pentyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, etc. Benzotriazole series, 1,2,2,6,6-pentamethyl-4-piperidyl 1,2,3,4-butanetetracarboxylate, 1,2,2,6,6-pentamethyl-4-tridecyl 1,2 , 3,4-Butanetetraca Examples include hindered amines such as boxylate, benzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 4-dodecyloxy-2-hydroxybenzophenone, and salicylic acids such as phenyl salicylate, and at least one of these Can be used.
[0024]
As an ultraviolet absorber, what is shown by following Structural formula (9)-(16) can further be mentioned, for example.
[0025]
[Chemical 1]

[0026]
[Chemical formula 2]

[0027]
In the above formula, tC_FourH₉Is a tert-butyl group, t-C₈H₁₇Represents a tert-octyl group.
[0028]
B: Recording medium
As the recording medium that can be used in the present invention, any recording medium can be used as long as it has a porous ink-receiving layer and performs recording by adhering ink. However, in the present invention, since the recording medium is impregnated with the image fastness improving agent, the medium is preferably a medium in which the image fastness improving agent does not show through. The recording medium according to the present invention is particularly suitable when a recording medium in which the porous structure of the ink receiving layer is formed of fine particles and the coloring material is adsorbed to the fine particles uses the inkjet method. is there. Such an ink jet recording medium is preferably a so-called absorption type in which ink is absorbed by a gap formed in an ink receiving layer on a support. The absorption type ink receiving layer is mainly composed of fine particles, and has a porous structure containing a binder and other additives as required.
[0029]
Examples of fine particles include inorganic pigments such as silica, clay, talc, calcium carbonate, kaolin, alumina or alumina hydrate, diatomaceous earth, titanium oxide, hydrotalcite, zinc oxide, urea formalin resin, ethylene resin And organic pigments such as styrene resins, and one or more of these are used. Examples of suitable binders include water-soluble polymers and latex. For example, polyvinyl alcohol or a modified product thereof, starch or a modified product thereof, gelatin or a modified product thereof, gum arabic, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, SBR latex, NBR latex, methyl methacrylate-butadiene copolymer Polymeric latex, functional group-modified polymer latex, vinyl copolymer latex such as ethylene vinyl acetate copolymer, polyvinyl pyrrolidone, maleic anhydride or copolymer thereof, acrylic ester copolymer, etc. are used. One selected or a combination of two or more can be used as necessary.
[0030]
Other additives can be used in the ink receiving layer, for example, a dispersant, a thickener, a pH adjuster, a lubricant, a fluidity modifier, a surfactant, an antifoaming agent, if necessary. Examples include release agents, fluorescent brighteners, ultraviolet absorbers, and antioxidants.
[0031]
A particularly suitable recording medium according to the present invention is preferably a recording medium having an ink receiving layer mainly composed of fine particles having an average particle diameter of 1 μm or less as the fine particles. Particularly preferable examples of the fine particles include silica or aluminum oxide fine particles. The reason why it is particularly effective in aluminum oxide fine particles and silica is considered as follows. That is, the colorant adsorbed on the aluminum oxide fine particles and silica is NO._X, SO_XIt was found that the color material was easily faded by gases such as ozone. However, these fine particles are likely to attract the gas, and the gas exists near the color material, so the color material is likely to fade. It is. A preferable silica fine particle is a silica fine particle typified by colloidal silica. Colloidal silica itself is also available from the market, and particularly preferable examples include those described in Japanese Patent Nos. 2803134 and 2881847. Preferable examples of the aluminum oxide fine particles include alumina hydrate fine particles. As one of such alumina-based pigments, preferred is an alumina hydrate represented by the following formula.
[0032]
Al₂O_3-n(OH)_2n・_mH₂O
In the above formula, n represents an integer of 1, 2 or 3, and m represents a value of 0 to 10, preferably 0 to 5. However, m and n are not 0 at the same time. mH₂O is often mH₂Since m also represents a detachable water phase that does not participate in the formation of the O crystal lattice, m can take an integer or a non-integer value. Also, when this type of material is heated, m can reach a value of zero.
[0033]
Alumina hydrate is generally used for hydrolysis of aluminum alkoxide and sodium aluminate as described in U.S. Pat. No. 4,242,271 and U.S. Pat. No. 4,420,870. It is preferable to use a solution prepared by a known method such as a method of neutralizing by adding an aqueous solution of sodium sulfate, aluminum chloride or the like to an aqueous solution of sodium aluminate or the like described in US Pat.
[0034]
Furthermore, the ink jet recording medium using these alumina hydrates is excellent in affinity, absorbability and fixability with the image fastness improver according to the present invention, and realizes the above-mentioned photographic image quality. Therefore, the present invention is more suitable for applying the present invention because of its excellent gloss, transparency, and fixing property of coloring materials in recording liquids such as dyes.
[0035]
The mixing ratio between the fine particles of the ink jet recording medium used in the present invention and the binder is preferably in the range of 1: 1 to 100: 1. By setting the amount of the binder within the above range, it is possible to maintain a pore volume suitable for impregnation of the image fastness improving agent into the ink receiving layer. The preferable content of aluminum oxide fine particles or silica fine particles in the ink receiving layer is 50% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, and 99% by weight or less. Most preferred. The coating amount of the ink receiving layer is 10 g / m in terms of dry solid content in order to improve the impregnation property of the image fastness improving agent.²Preferably, it is 10-60 g / m.²Is most preferred.
[0036]
The recording medium used in the present invention preferably has a support for supporting the ink receiving layer described above, but the support is not particularly limited, and the ink receiving layer having the porous structure described above is formed. Any material can be used as long as it provides rigidity that can be transported by a transport mechanism such as an ink jet printer. For example, one having a porous layer formed by coating an inorganic pigment such as barium sulfate, titanium oxide, zinc oxide or the like with a binder between the support and the ink receiving layer, or using a resin-coated paper for the support Also good. The recording medium having a porous layer between the support and the ink receiving layer is a more preferable embodiment of the present invention described above, “the hole in which the image forming region exists in the thickness direction of the ink receiving layer. It is more effective when it is used for a “recorded product having a part in which all or substantially all of the part is filled with an improving agent”. In other words, the recorded matter in which all or substantially all of the holes existing in the thickness direction of the ink receiving layer are filled with the improver is left in a high temperature / high humidity environment for a long time. However, it is possible to extremely effectively suppress the occurrence of stickiness of the surface due to the exudation of the improver on the surface of the recorded material, and it is possible to obtain a recorded material that is extremely excellent in storage stability.
[0037]
The reason why the above-mentioned effects can be obtained is not clear, but the image fastness improver supplied to fill all or substantially all of the pores existing in the thickness direction of the ink receiving layer has a gas permeability. For example, since it is difficult to pass through the bariter layer, the filling of the hole with the image fastness improving agent is surely performed, and further, air and moisture present in the hole in the ink receiving layer are also shown in FIG. As shown schematically in Fig. 4, air or moisture remains in the ink receiving layer as it is transferred to or adsorbed to the porous layer (1301) with the filling process of the fastness improving agent into the pores. It is thought that this is because it is possible to suppress or prevent this.
[0038]
C: Method for producing recorded matter and method for improving image fastness
The recorded matter according to the present invention includes an ink receiving layer (1003) having a porous structure containing fine particles (1005) on the surface of a support (1000), and an image formed by a color material (1009) adsorbed on the surface of the fine particles. In which the image fastness improving agent (hereinafter referred to as improving agent) 1001 is added.
[0039]
For example, as shown in FIG. 2, all or substantially all of the color material in which the area where the image is formed is distributed in the thickness direction of the ink receiving layer is in the image fastness improving agent. A mode in which all or substantially all of the pores having a portion or distributed in the thickness direction of the ink receiving layer are filled with the image fastness improving agent is more preferable, and the image fastness is further improved. . Further, the ink receiving layer of the recorded matter according to the present invention is not particularly limited to those containing fine particles as long as it has a porous structure.
[0040]
In the case of the above-described more preferable embodiment of the present invention, the reason why an improvement in the color of a recorded matter (printed matter) or a tremendous improvement in gas resistance is achieved by ink formed on a recording medium having a receiving layer Is thought to be due to the following mechanism.
[0041]
FIG. 1 schematically shows a cross-sectional structure of a so-called coated paper provided with a porous ink-receiving layer made of fine particles on a support made of paper or the like. In FIG. 1, reference numeral 1000 denotes a support, and 1003 denotes an ink receiving layer held on the support 1000. The ink receiving layer 1003 forms a porous structure including fine particles 1005, and the fine particles are fixed by a binder (binder) 1007. Then, in the process in which the ink droplets applied to the coated paper soak into the ink receiving layer 1003, the color material 1009 contained in the ink is adsorbed on the surface of the fine particles 1005, and an image is formed.
[0042]
After the image fastness improving agent 1001 is supplied to the surface of the coated paper thus recorded, the coloring material relatively deep in the ink receiving layer is also included in the improving agent. When the rubbing treatment is performed after the ink is supplied, the image fastness improving agent fills the hole in the ink receiving layer 1003, here, the gap (gap) 1011 between the fine particles 1005. Since the improver is a non-aqueous substance, the aqueous medium of the aqueous ink trapped between the particles is successively replaced, and the periphery of the color material adsorbed on the surface of the fine particles is also covered. Finally, as shown in FIG. 2, the gap 1011 is filled with the improving agent 1001, and all or substantially all of the color material distributed in the thickness direction of the ink receiving layer is the image fastness improving agent. When all or substantially all of the pores existing in the thickness direction of the ink receiving layer are filled with the improver, the coloring material 1009 is in the atmosphere._XOr NO_XThe contact with the gas or the moisture containing them is cut off. As a result, it is considered that the deterioration of the color material in the ink receiving layer is suppressed and the fastness of the image is further improved. Further, the effect of improving the color fastness, printing density, and glossiness obtained together with the effect of improving the fastness of the image according to the present invention is the effect of the substance forming the ink receiving layer and the pores (air), here fine particles. It is considered that the irregular reflection of light on the surface and inside of the ink receiving layer caused by the difference in refractive index between the gap and air (air) is suppressed by filling the gap with an image fastness improving agent. .
[0043]
The image fastness improving agent according to the present invention is preferably applied to the ink receiving layer in a liquid state. Therefore, penetration into the ink receiving layer is easily performed, and deformation is performed corresponding to the shape of the porous structure in the ink receiving layer, so that the effect of incorporating the color material into the image fastness improving agent is sufficiently exhibited. It is possible. In addition, the porous structure of the ink receiving layer, for example, the inner wall of the gap or the fine particles contained when the recording material causes an acceptable deformation by being held in the ink receiving layer as a liquid. The contact state of the image fastness-improving agent with the outer wall is maintained well.
[0044]
On the other hand, when the image fastness improving agent is in a solid state at a temperature such as wax, pressure is required for the penetration into the ink receiving layer, and a uniform penetration state is difficult to obtain. Furthermore, when it is applied in a state diluted with a volatile solvent and solidifies after application, or contains a component that solidifies after application in liquid form, it takes in moisture and bubbles during the solidification process. When the volume of the improver phase is reduced due to solidification, a void is generated between the improver phase and the porous structure, and the colorant has a protective function. May decrease. Confirm that the ink receiving layer is held in a liquid state by confirming that there is no thermal behavior (endothermic or exothermic) at the time of dissolution by a method such as local thermal analysis of the ink receiving layer. It is possible.
[0045]
The rubbing treatment used in the present invention refers to at least one of wiping and polishing for positively filling the hole in the ink receiving layer with the fastness improving agent.
[0046]
(1) First embodiment
As described above, one embodiment of the method for producing a recorded matter or the method for improving image fastness according to the present invention includes an ink receiving layer having a porous structure, and by applying ink or ink droplets to the ink receiving layer. Further, there is a method in which the above-mentioned image fastness improving agent is supplied to the surface of the ink receiving layer of a recording sheet on which images such as characters and pictures are recorded, followed by rubbing treatment. Here, the improver may be supplied and applied only to at least a part of the image recording portion of the recording sheet, but it is most preferable to apply it to the entire surface of the recording sheet. This can more reliably suppress the color material in the ink receiving layer from being attacked by a gas such as ozone.
[0047]
Further, as described above, in a more preferred aspect of the present invention, all or substantially all of the holes existing in the thickness direction of the ink receiving layer are filled with the image fastness improving agent. In this case, it is appropriate that the supply amount of the image fastness improver is set in consideration of the amount of time required for painting and the amount in which the hole is completely filled and the amount absorbed by the coating member. is there. Here, the amount that the hole portion is completely filled is considered from the degree of porosity (oil absorption amount, etc.) of the ink receiving layer in the case of an ink receiving layer made of fine particles. By supplying and coating such an amount of the image fastness improving agent, it is possible to almost certainly fill the pores of the ink receiving layer with the image fastness improving agent.
[0048]
Specifically, for example, in order to improve the fastness of an image formed on a recording medium having an oil absorption of 0.3 cc, an image fastness improver of about 0.3 g is applied and a rubbing treatment is performed. By doing so, it is possible to obtain a sufficient robustness improving effect. This indicates that not only the surface portion of the ink receiving layer is covered but also the effect of the present invention is achieved by the image fastness improving agent filling the pores of the ink receiving layer. is there.
[0049]
Here, the application method of the image fastness improving agent is not particularly limited, such as brush coating, spray coating, roller coating, spatula coating, sponge coating, etc. As a specific method, for example, as shown in FIG. A rubbing member including a container 5003 (dispenser, etc.) having a function 5001 (spray, pump, etc.) capable of supplying an appropriate amount of an image fastness improving agent to the surface of the ink receiving layer. This can be realized by using an image robustness improvement kit in which and are set.
[0050]
As another embodiment, as shown in FIGS. 4A and 4B, an image fastness improving agent storage unit 4001 containing an image fastness improving agent, and application of the image fastness improving agent. The image fastness improving agent is supplied and rubbed at the same time using an applicator that is integrated with the member 4002 and configured to allow the image fastness improving agent in the storage section to exude onto the surface of the coating member. You may do it. In addition, when the image fastness improving agent of the coating member 4002 is decreased, the image fastness improving agent is soaked into the coating member by applying pressure to the image fastness improving agent storage unit 4001. May be. Reference numeral 4003 denotes a lid 4002. In order to obtain a recorded matter excellent in image fastness by the method according to the present invention, an image having high fastness can be easily obtained by using a set of the recording medium and the image recording property improver. .
[0051]
(2) Other embodiments
As another embodiment of the method for producing a recorded matter or the method for improving the image fastness according to the present invention, there can be mentioned a method for processing without any manual intervention in the recording apparatus. FIG. 6 is a schematic cross-sectional view of an apparatus for obtaining a recorded matter having excellent image fastness, and performs recording of an image on a recording medium by an inkjet method and processing for imparting fastness to the formed image. Each means is provided. In FIG. 6, reference numeral 25 denotes a casing, and reference numeral 1 denotes a stacked unused recording medium, which is placed substantially horizontally on a supply tray (paper feeding cassette) 2.
[0052]
Reference numeral 3 denotes a suction cup, which is moved from the position a in the drawing to a position b in contact with the uppermost one of the unused recording sheets 1 by a suction cup moving mechanism (not shown), and sucks the uppermost sheet. Can be lifted. At this time, a suction mechanism (not shown) reduces the pressure inside the suction cup 3 while the suction cup 3 is in contact with the recording paper, and adsorbs the uppermost sheet of the recording paper 1 to remove the recording paper from the other. Separate the recording paper. In this state, the suction cup moving mechanism moves to the position c in the figure, and the leading edge of the separated recording sheet can be inserted between the conveying rollers 4 and 5. Thereafter, the suction operation by the suction mechanism is stopped, the suction force of the suction cup 3 is released, and the restraint of the recording paper by the suction cup 3 can be released.
[0053]
The transport rollers 4 and 5 are rotationally driven by a drive source such as a transport motor (not shown) via a clutch mechanism (not shown). Reference numerals 6 and 7 are guide plates which are arranged to face each other with a predetermined interval, and form a supply path for recording paper to be conveyed by the rotation of the conveying rollers 4 and 5. The cross-sectional shape of the supply path formed by the guide plates 6 and 7 is substantially semicircular, and extends from the vicinity of the conveying rollers 4 and 5 to the upper sub-scanning rollers 8 and 9. These sub-scanning rollers 8 and 9, together with a second sub-scanning roller pair 10 and 11 arranged in parallel in the left direction in the figure, sandwich the conveyed recording paper, and will be described later with a control unit (not shown). ) And so on. A guide plate 15 regulates the position of the recording paper between the sub-scanning rollers 8, 9, 10, and 11. A recording head (inkjet head) 12 has a plurality of ink ejection nozzles arranged in the conveyance direction of the recording paper 1. Note that the recording head 12 may include a plurality of inkjet heads that discharge inks of different colors. An ink tank 13 stores ink to be supplied to the recording head 12. The recording head 12 and the ink tank 13 are mounted on a carriage, and can be moved in a direction substantially orthogonal to the recording paper conveyance direction by a carriage guide disposed substantially parallel to the rotation axis of the sub-scanning rollers 8 to 11. Is held in.
[0054]
Reference numeral 16 denotes an unused second recording paper stored in a stacked manner in the upper recording paper storage unit. Reference numeral 17 denotes a pressure plate on which the stacked recording paper 16 is placed and appropriately pressed in the direction of the separation roller 18. Reference numerals 19 and 20 denote guide plates, which form a second supply path for guiding the leading edge of one recording sheet taken out by the separation roller 18 to the sub-scanning rollers 8 and 9.
[0055]
21, 22, 23, and 24 are means for detecting the presence and the quality of each recording paper 1 and 16 disclosed in, for example, JP-A-1-264879. 21 and 23 are light sources for irradiating the surfaces of the recording papers 1 and 16 with light of a predetermined wavelength, and 22 and 24 are photodetectors for receiving the light reflected from the surface of the recording papers. is there.
[0056]
Such detection of the quality of the recording paper by reflected light is caused by the fact that the roughness of the surface differs depending on the type of recording paper, and the degree of light diffusion varies accordingly. . For example, when the surface of plain paper is viewed microscopically, the fibers are intertwined and the diffusion of the surface is large, so the outputs of the detectors 22 and 24 are small. On the other hand, in the case of a sheet having a smooth surface and a low degree of light diffusion, the outputs of the detectors 22 and 24 become large. Whether the recording paper corresponding to the first separation mechanism using the suction cup 3 or the second separation mechanism using the separation roller 18 is loaded in the corresponding cassette by using such light detection means. It is possible to determine whether or not a recording sheet suitable for recording is loaded.
[0057]
Reference numerals 26 and 27 denote guide plates that form a conveyance path for guiding the recording paper discharged along with the rotation of the sub-scanning rollers 10 and 11 after the recording by the recording head 12 is completed. A planar heater (not shown) is attached to the guide plate, and heats the recording paper in the conveyance path formed by the guide plates 26 and 27 to accelerate the drying of the ink ejected on the recording paper. .
[0058]
An image fastness improving agent is supplied to the recording surface of the recorded matter thus obtained, and an area filled with the image fastness improving agent is formed in the ink receiving layer of the recorded matter.
[0059]
The liquid 52 is an image fastness improving agent according to the present invention, and is supplied to the container 51 from a tank (not shown) by a supply device (not shown), and the liquid level in the container 51 is always within a predetermined range. Is automatically supplied and controlled. 53 is a roller for applying a fastness improver, and its surface 53 a has a sponge-like structure into which the fastness improver 52 can permeate, and a part thereof is in contact with the fastness improver 52 in the container 51. Thus, when the liquid application roller 53 is rotated by driving a drive source (not shown), the fastness improving agent 52 can be uniformly infiltrated into the surface portion 53a. Reference numeral 54 denotes a conveyance roller for nipping and conveying the recording medium in cooperation with the application roller 53. The transport roller 54 is separated from the application roller 53 when the recording medium is not sandwiched so that the fastness improving agent 52 does not adhere to the surface, and only when the recording medium is interposed. It is desirable to sandwich the recording medium in contact with the application roller 53 and the conveyance roller 54. A drying heater 55 is used to dry the recording paper coated with the fastness improving agent 52.
[0060]
With the above configuration, after the recording by the recording head 12 is completed, before the trailing edge of the recording sheet is separated from the second sub-scanning roller pair 10, 11, the leading edge of the recording medium is the conveying roller 54 and the coating roller 53. To reach the position. The recording medium is sandwiched between the conveying roller 54 and the application roller 53, and the fastness improving agent 52 is uniformly supplied to one surface of the recording medium as the rollers 53 and 54 rotate. Further, it is rubbed to fill the gaps of the ink receiving layer. The recording paper filled with the liquid is further rubbed as necessary, and is then discharged out of the apparatus through the discharge outlet 34 by the rotation of the discharge roller 33.
[0061]
In FIG. 6, the image recording apparatus in which the ink jet recording and the filling of the image fastness improving agent are processed in the same apparatus has been described. However, the present invention is not limited to this, and the image recording unit and the fastness improvement are described. An image recording apparatus having a configuration in which the liquid filling portion is separated, and an image fastness improving liquid coating apparatus in which the fastness improving liquid filling portion is independent from the image forming portion are also within the scope of the present invention. belongs to.
[0062]
【Example】
The present invention will be further described below with reference to examples and comparative examples.
(Preparation of image fastness improver)
The image fastness improvers of Examples 1 to 6 were prepared by mixing the saturated fatty acid ester shown below and an additive, that is, an ultraviolet absorber at a ratio shown in Table 2.
Group A. Saturated fatty acid glycerides
A-1. Compound name: Capric acid triglyceride
Molecular weight 491
[0063]
[Chemical 3]

[0064]
A-2. Compound name: Glyceryl tri-2-ethylhexanoate
Molecular weight 471
[0065]
[Formula 4]

[0066]
A-3. Compound name: Triisostearic acid glyceride
Molecular weight 890
[0067]
[Chemical formula 5]

[0068]
Group B: Additive
B-1. Product name: ADK STAB LA-63P (Asahi Denka Co., Ltd.)
[0069]
[Chemical 6]

[0070]
Comparative Examples 1-2
Comparative Example 1 is a case where no image fastness improving agent is used.
Comparative Example 2 is C-1. Acrylic resin solution Acrylic resin emulsion Product name: Boncoat 4001 When Dainippon Ink & Chemicals, Inc. is used.
[0071]
(Example of recording medium production)
First, the base material was produced as follows. Cationized starch 0.60 was added to a pulp slurry consisting of 80 parts by mass of hardwood bleached kraft pulp (LBPK) having a freeness of 450 ml CSF (Canadian Standardrad Freeness) and 20 parts by weight of softwood bleached kraft pulp (NBPK) having a freeness of 480 ml CSF. Mass parts, 10 parts by weight of heavy calcium carbonate, 15 parts by weight of light calcium carbonate, 0.10 parts by weight of alkyl ketene dimer, 0.03 parts by weight of cationic polyacrylamide and 0.40 parts by weight of sulfuric acid band After adjusting, the paper was made with a long paper-making paper, subjected to a three-stage wet press, and dried with a multi-cylinder dryer. Thereafter, the oxidized starch aqueous solution is 1.0 g / m in terms of solid content with a size press device.²After impregnation, dry and machine calender finish, basis weight 155g / m²A substrate having a Steecht size of 100 seconds, an air permeability of 50 seconds, a Beck smoothness of 30 seconds, and a Gurley stiffness of 11.0 mN was obtained.
[0072]
Next, an undercoat layer was formed on the substrate obtained above as follows. First, as a coating liquid used for forming the undercoat layer, 100 parts by mass of kaolin (Ultra White 90, manufactured by Engelhard) / zinc oxide / aluminum hydroxide having a weight ratio of 65/10/25, and commercially available 7 parts by weight of a commercially available styrene-butadiene latex was added to a slurry with a solid content of 70% consisting of 0.1 parts by weight of a polyacrylic acid-based dispersant, and adjusted to a solid content of 60%. A composition was obtained. Next, this composition was dried at a coating amount of 15 g / m.²As shown in the figure, it was coated on both sides of the substrate with a blade coater and dried. Then, machine calender finishing (linear pressure 150 kgf / cm), basis weight 185 g / m²A substrate with an undercoat layer having a Steecht size of 300 seconds, an air permeability of 3,000 seconds, a Beck smoothness of 200 seconds, and a Gurley stiffness of 11.5 mN was obtained. The whiteness of the base material with the undercoat layer was measured for each of the five A4 size samples cut and obtained as an average value. As a result, L: 95, a^*: 0, b^*: -2 (determined as the hue of JIS Z 8729).
[0073]
Next, an ink receiving layer was formed. After coating in the second surface treatment step, that is, as soon as the coating solution was impregnated in the undercoat layer, the ink receiving layer was formed on the undercoat layer as it was. did. The coating liquid and coating method used for forming the ink receiving layer at that time are as follows.
[0074]
Sodium aluminate was added to a 4 wt% solution of aluminum chloride to adjust the pH to 4. Then, it heated up to 90 degreeC, stirring, and stirred for a while. Thereafter, sodium aluminate was added again to adjust the pH to 10, and the aging reaction was carried out for 40 hours while maintaining the temperature. Then, it returned to room temperature and adjusted pH to 7-8. The dispersion was subjected to a desalting treatment, followed by a peptization treatment with acetic acid to obtain a colloidal sol. The colloidal sol of alumina hydrate was concentrated to obtain a 17% by weight solution. Polyvinyl alcohol PVA117 (trade name: manufactured by Kuraray Co., Ltd.) was dissolved in pure water to obtain a 9% by weight solution. The colloidal sol of alumina hydrate and the polyvinyl alcohol solution were mixed and stirred so that the alumina hydrate solid content and the polyvinyl alcohol solid content were 10: 1 by weight to obtain a dispersion. This is 35g / m in dry coating amount with a die coater.²The coating was performed at 30 m / min. And it dried at 170 degreeC and formed the ink receiving layer. Using a rewetting cast coater on the surface of the ink receiving layer of this recording medium, a rewetting treatment using hot water was performed to obtain a recording medium. The oil absorption of the recording medium is about 21cc / m²Met.
[0075]
  A recorded matter in which an image is recorded on the recording medium created as described above is created by the following method.Reference examples 1 ~ 5The following method using the image fastness improving agent and the compound of Comparative Example 21-5Various image fastness tests were conducted according to the above. Moreover, the recorded material which did not process anything was similarly evaluated as Comparative Example 1.
[0076]
    Inkjet printer (trade name: BJ-F870 made by Canon) and genuine ink tank (trade name: BCI-6BK, BCI-6Y, M, C, BCI-6PM, BCI-6PC) On the recording surface of the recording medium obtained above, 100%, 80% for each color of black, cyan, magenta and yellow as composite colors, composite black, leaf green, skin color and sky blue as composite colors 60%, 40%, 20%, and 10% solid patches of each density were printed to produce recorded matter. Note that the ink used for printing is a genuine product of the printer, and is a water-based ink that contains a water-soluble dye. Next, the above-mentioned various image fastness improvers and the compounds of Comparative Examples 1 and 2 were applied to the surface of the ink receiving layer of this recorded matter at a ratio of about 0.3 g per area of 126 mm × 89 mm, and natural cotton was added. A rubbing process is performed over the entire image with a rubbing member made of a material, and Example 1Reference examples 1-5And the recorded matter of Comparative Examples 1-2 was obtained. For each recorded matter, each color O.D. A patch having a D of about 1.0 was selected and used for the following image fastness tests.
[0077]
Evaluation method of light resistance and gas resistance: The image density before the test and the image density after the test of the above recorded matter were measured using a spectrophotometer / spectrino (manufactured by Gretag Macbeth Co.). The light resistance and gas resistance evaluation were determined based on the criteria described below, and the results are shown in Table 1.
[0078]
    (Test method)
  1.Light resistance test 1
  According to the following test conditions, a light resistance exposure test was performed using a xenon fade meter. This test is an image fastness test that takes into account the effect of sunlight through windows.
Test conditions;
Irradiation amount: 50 klux
Test time: 100 hours
Temperature and humidity conditions in the test chamber: 30 ° C, 45% RH
Filter: (Outer) Soda lime, (Inner) Borosilicate
Light resistance evaluation:
  Evaluation was made based on the reflection density residual rate (ΔE) data after the light resistance exposure test with reference to the standard of ISO10977 (1993). Specifically, with respect to the recording portion using the single color ink, the reflection density remaining rate indicated by the recording portion after the test was measured and evaluated according to the criteria shown in Table 1 below. On the other hand, for the composite color recording portion formed by superimposing a plurality of colors of ink, in addition to the reflection density remaining rate of each recording portion after the test, each of the plurality of constituent colors constituting each composite color recording portion The reflection density residual rate after the light resistance exposure test was measured, and the difference in the obtained reflection density residual rate was calculated and evaluated according to the criteria shown in Table 1. The reason for adding the difference in the reflection density residual ratio of the constituent colors constituting the composite color recording part to the evaluation of the composite color recording part is that the image fastness of the composite color recording part is only the reflection density residual ratio of the recording part itself. In other words, the degree of fading of each of the plurality of constituent colors constituting the composite color recording unit has a great influence on the visual image quality. That is, even when the reflection density residual ratio of the composite color recording portion itself is large, the reflection density has greatly changed before and after the test for any one of the constituent colors constituting the composite color. This is because the visual color balance may be lost and the color fading may be felt visually.
[0079]
In Table 1, for example, the density residual ratio is 90% or more, even if the lowest value of the reflection density residual ratio of each recording portion of black, cyan, magenta, yellow, composite black, leaf green, flesh color, and sky blue is recorded. It indicates 90% or more. In addition, for example, the difference in density residual ratio is less than 5% because, in the above-described four-color composite color recording section, the reflection density residual ratio before each test of the constituent colors constituting each composite color recording section. This is the case where the maximum value difference is less than 5%. The difference in density residual ratio is 5% or more and less than 10% because the maximum value of the difference in reflection density residual ratio of each component color constituting each of the four-color composite color recording portions is 5% or more and 10%. It is a case of less than%.
[0080]
[Table 1]

[0081]
The evaluation results are shown in Table 2.
[0082]
  2.Light resistance test 2
  According to the following test conditions, a light exposure test was performed using a fluorescent light resistance tester. This test is an image fastness test considering the influence of fluorescent light in the room.
Test conditions;
Irradiation amount: 60 klux
Test time: 480 hours
Temperature and humidity conditions in the test layer: 30 ° C, 45% RH
Filter: Soda Lime
Light resistance evaluation;
  The light resistance is calculated from the concentration residual rate data after the light resistance exposure test with reference to the standard of ISO10977 (1993).1Evaluation was performed using the same evaluation criteria. The results are shown in Table 2.
[0083]
  3.Gas resistance test
  An ozone exposure test was performed using an ozone test apparatus (trade name: ozone weatherometer, manufactured by Suga Test Instruments Co., Ltd.).
Test conditions;
Exposure gas composition: O_Three3ppm
Test time: 6 hours
Temperature and humidity conditions in the test layer: 45 ° C, 55% RH
Gas resistance evaluation;
  Concentration residual rate data after ozone exposure test1Evaluation was performed using the same evaluation criteria as in the above evaluation. The results are shown in Table 2.
[0084]
  4).Yellowing test
  (Test method and evaluation method)
  Example 1 for an unprinted recording mediumReference examples 1-5Each of the image fastness improvers and the compound of Comparative Example 2 was applied in the same manner as described above, followed by rubbing treatment.Reference examples 1-5A sample of Comparative Example 2 was prepared, an untreated sample as Comparative Example 1 was added, each sample was left in the following environment, and the colors of the recording surfaces before and after the test were compared. The results are shown in Table 2.
Test conditions;
Test layer temperature and humidity conditions: 50 ° C., 80% RH
Test time: 240 hours
[0085]
[Table 2]

[0086]
  5).Gloss test
  Example 1 is newly applied to an unprinted recording medium.Reference examples 1-5Each sample was applied in the same manner as described above, and a rubbing treatment was performed to prepare a sample, and an untreated sample was prepared as Comparative Example 1. The glossiness of each of these three samples after storage at room temperature for 24 hours was measured by the method defined in JIS-Z-8741. The results are shown in Table 3.
[0087]
[Table 3]

[0088]
  Example 1 newlyReference examples 1-5Recorded matter (100% solid patch) and Comparative Example 1 recorded matter (100% solid patch)1The density of each image was measured with Gretag Spectroleuno (manufactured by Gretag Macbeth) after being prepared in the same manner as the sample used in and stored at room temperature for 24 hours. The results are shown in Table 4.
[0089]
[Table 4]

[0090]
【The invention's effect】
According to the present invention, the robustness of an ink-jet recorded image is improved. In particular, even when the ink-jet recorded image is used for display in a normal indoor environment such as a home or office, it is possible to dramatically prevent the image from fading. . Further, the present invention can improve image fastness without deteriorating the recording quality of a recorded image.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view schematically showing a cross-sectional structure of a recording medium used in the present invention.
FIG. 2 is a schematic explanatory view of a method for improving image fastness according to the present invention, and is a schematic cross-sectional view showing a state in which an improving agent is filled in a gap in an ink receiving layer.
FIG. 3 is an explanatory diagram of the behavior of water molecules in the ink receiving layer when a recording medium support having a dense porous layer on the surface on the ink receiving layer side is used.
FIG. 4 is an embodiment of an applicator according to the present invention. (A) is a schematic perspective view which shows the form at the time of use, (b) is a schematic perspective view which shows the form where the application part was protected with the lid | cover suitable for accommodation or carrying.
FIG. 5 is a schematic sectional view of an atomizer according to the present invention.
FIG. 6 is a schematic sectional view of an ink jet recording apparatus according to the present invention.
[Explanation of symbols]
1000 Support
1001 Image fastness improver
1003 Ink receiving layer
1005 fine particles
1007 binder
1009 Color material
1011 Gaps in the ink receiving layer
1301 Porous layer
4001 Image fastness storage section
4002 Image fastness improver application part
4003 lid
5001 Dispensing means (spray part)
5003 Image fastness improving agent storage

Claims (2)

An image fastness improving method for imparting an image fastness improving agent to a recorded matter in which an image is formed of a color material on an ink receiving layer having a porous structure,
The image fastness improver consists only of capric acid triglyceride,
An image fastness improving method, comprising: applying a rubbing treatment after applying an image fastness improving agent to the recorded matter . By performing the rubbing process, image fastness according to claim 1, characterized in that the entire hand holes which are present in the thickness direction of the ink-receiving layer, filled by the image fastness enhancing agent Improvement method.

Images