JP3914977B2 - Electrophotographic image-receiving sheet support, method for producing the same, electrophotographic image-receiving sheet, and image forming method - Google Patents

Description

【０１５２】
本発明のトナー受像層は、前記支持体上に、トナー受像層に用いられるポリマーを含有する塗工液をワイヤーコーター等で塗布し、乾燥することによって設けられる。本発明で使用される前記ポリマーの成膜温度は、プリント前の保存に対しては、室温以上が好ましく、トナー粒子の定着に対しては１００℃以下が好ましい。
【０１５３】
本発明のトナー受像層は、乾燥後の塗布質量は、例えば、１〜２０ｇ／ｍ^２が好ましく、４〜１５ｇ／ｍ^２がより好ましい。
前記トナー受像層の厚みとしては、特に制限はなく、目的に応じて適宜選定することができるが、１〜３０μｍが好ましく、２〜２０μｍがより好ましい。
【０１５４】
−トナー受像層の諸物性−
前記トナー受像層は、白色度が高いことが好ましい。前記白色度としては、ＪＩＳ Ｐ ８１２３に規定される方法で測定して、８５％以上が好ましい。また、４４０ｎｍ〜６４０ｎｍの波長域で、分光反射率が８５％以上、かつ同波長域の最大分光反射率と最低分光反射率の差が５％以内であることが好ましい。更には、４００ｎｍ〜７００ｎｍの波長域で分光反射率が８５％以上、かつ同波長域の最大分光反射率と最低分光反射率の差が５％以内であることがより好ましい。
また、前記白色度としては、具体的には、ＣＩＥ １９７６（Ｌ^＊ａ^＊ｂ^＊）色空間において、Ｌ^＊値は８０以上が好ましく、８５以上がより好ましく、９０以上が更に好ましい。また、白色の色味はできるだけニュートラルであるのが好ましい。前記白色色味としては、Ｌ^＊ａ^＊ｂ^＊空間において、（ａ^＊）^２＋（ｂ^＊）^２の値は５０以下が好ましく、１８以下がより好ましく、５以下が更に好ましい。
【０１５５】
前記トナー受像層としては、光沢性が高いのが好ましい。光沢度としては、トナーが無い白色から最大濃度の黒色までの全領域において、４５度光沢度は６０以上が好ましく、７５以上がより好ましく、９０以上が更に好ましい。
但し、光沢度は１１０以下が好ましい。１１０を超えると金属光沢のようになり画質として好ましくない。
尚、前記光沢度は、ＪＩＳ Ｚ ８７４１に基づいて測定することができる。
【０１５６】
前記トナー受像層は、以下の項目の内の１項目の物性を有することが好ましく、更に好ましくは、複数の項目、最も好ましくは、全ての項目の物性を有することが適当である。
（１）トナー受像層のＴｇ（ガラス転移温度）が３０℃以上、トナーのＴｇ＋２０℃以下である。
（２）トナー受像層のＴ１／２（１／２法軟化点）が、６０〜２００℃、好ましくは、８０〜１７０℃である。ここで、前記１／２法軟化点は、特定の装置を使用し、特定の条件の下で、所定の押出加重を加えながら、初期設定温度（例えば、５０℃）で余熱時間、例えば、３００秒後に、所定の等速昇温速度で昇温した時の各温度における流出開始時と終了時のピストンストロークの差の２分の１となる温度で評価される。
（３）トナー受像層のＴｆｂ（流出開始温度）が、４０〜２００℃、好ましくは、トナー受像層のＴｆｂが、トナーのＴｆｂ＋５０℃以下である。
（４）トナー受像層の粘度が１×１０^５ＣＰになる温度が、４０℃以上、トナーのそれより低い。
（５）トナー受像層の定着温度における貯蔵弾性率（Ｇ'）が、１×１０^２〜１×１０^５Ｐａ、損失弾性率（Ｇ”）が、１×１０²〜１×１０^５Ｐａである。
（６）トナー受像層の定着温度における損失弾性率（Ｇ”）と、貯蔵弾性率（Ｇ'）との比である損失正接（Ｇ”／Ｇ'）が、０．０１〜１０である。
（７）トナー受像層の定着温度における貯蔵弾性率（Ｇ'）が、トナーの定着温度における貯蔵弾性率（Ｇ”）に対して、−５０〜＋２５００である。
（８）溶融トナーのトナー受像層上の傾斜角が、５０度以下、特に４０度以下である。
また、トナー受像層としては、特許第２７８８３５８号明細書、特開平７−２４８６３７号、同８−３０５０６７号、同１０−２３９８８９号公報等に開示されている物性等を満足するものが好ましい。
【０１５７】
前記（１）の物性は、示差走査熱量測定装置（ＤＳＣ）により測定することができる。前記（２）〜（３）の物性は、例えば、島津製作所製フローテスターＣＦＴ−５００又は５００Ｄを用いて測定することができる。前記（５）〜（７）の物性は、回転型レオメーター（例えば、レオメトリック社製ダイナミックアナライザーＲＡＤＩＩ）を用いて測定することができる。前記（８）の物性は、協和界面科学（株）製の接触角測定装置を用い、特開平８−３３４９１６号公報に開示した方法で測定することができる。
【０１５８】
前記トナー受像層としては、１×１０^６〜１×１０^１５Ω／ｃｍ^２の範囲（２５℃、６５％ＲＨの条件にて）の表面電気抵抗を有するのが好ましい。
前記表面抵抗が１×１０^６Ω／ｃｍ^２未満であると、トナー受像層にトナーが転写される際のトナー量が充分でなく、得られるトナー画像の濃度が低くなり易いことがある一方、表面電気抵抗が、１×１０^１５Ω／ｃｍ^２を超えると、転写時に必要以上の電荷が発生し、トナーが充分に転写されず、画像の濃度が低く、電子写真用受像シートの取り扱い中に静電気を帯びて塵埃が付着し易く、また複写時にミスフィード、重送、放電マーク、トナー転写ヌケ等が発生することがある。
【０１５９】
尚、前記支持体に対し、トナー受像層と反対側の面の表面電気抵抗としては、５×１０^８〜３．２×１０^１０Ω／ｃｍ^２が好ましく、１×１０^９〜１×１０^１０Ω／ｃｍ^２がより好ましい。
本発明において、前記表面電気抵抗の測定は、ＪＩＳ Ｋ ６９１１に準拠し、サンプルを温度２０℃、湿度６５％の環境下に８時間以上調湿し、同じ環境下で、アドバンテスト（株）製Ｒ８３４０を使用し、印加電圧１００Ｖの条件で、通電して１分間経過した後に測定することで得られる。
【０１６０】
〔バック層〕
前記バック層は、本発明の電子写真用受像シートにおいて、裏面出力適性付与、裏面出力画質改良、カールバランス改良、機器通過性改良等の目的で、支持体に対して、トナー受像層の反対側に設けられ、上述した表面粗さ性状を備えたものである。
前記バック層は、前記トナー受像層と同様の水分散系樹脂、特に、ソープフリー型水分散性ポリマーを含有し、更にコロイド状シリカを含有することが好ましい。
前記コロイド状シリカとしては、一般に市販されているシリカゾル懸濁液、例えば、ルドックスＨＳ、ルドックスＡＳ等（デュポン社製）、スノーテックスＯ、スノーテックスＣ、スノーテックス２０等（日産化学工業社製）などが挙げられる。前記コロイド状シリカの含有量は、バック層用組成物全体に対し１〜５０質量％が好ましい。
前記バック層の色としては、特に制限はないが、本発明の電子写真用受像シートが、裏面にも画像を形成する両面出力型受像シートの場合、バック層も白色であることが好ましい。白色度及び分光反射率は、表面と同様に８５％以上が好ましい。
前記バック層の厚みは、通常、０．１〜１０μｍが好ましい。
【０１６１】
［その他の層］
前記その他の層としては、例えば、表面保護層、密着改良層、中間層、下塗り層、クッション層、反射層、色味調製層、保存性改良層、接着防止層、アンチカール層、及び、平滑化層等が挙げられる。これらの層は、単層構成であってもよく、２以上の層より構成されていてもよい。
【０１６２】
−表面保護層−
前記表面保護層は、本発明の電子写真用受像シートにおける表面の保護、保存性の改良、取り扱い性の改良、筆記性の付与、機器通過性の改良、アンチオフセット性の付与等の目的で、前記トナー受像層の表面に設けることができる。該表面保護層は、１層であってもよいし、２層以上の層からなっていてもよい。表面保護層には、バインダーとして各種の熱可塑性樹脂、熱硬化性樹脂等を用いることができ、前記トナー受像層と同種の樹脂を用いるのが好ましい。但し、熱力学的特性や、静電特性等は、トナー受像層と同じである必要はなく、各々最適化することができる。
【０１６３】
前記表面保護層には、トナー受像層に使用可能な、前述の各種の添加剤を配合することができる。特に、前記表面保護層には、本発明で使用する離型剤と共に、他の添加剤、例えば、マット剤等を配合することができる。なお、前記マット剤としては、種々の公知のものが挙げられる。
本発明の電子写真用受像シートにおける最表面層（例えば、表面保護層が形成されている場合には、表面保護層等）としては、定着性の点で、トナーとの相溶性が良いのが好ましい。具体的には、溶融したトナーとの接触角が、例えば０〜４０度であることが好ましい。
【０１６４】
−密着改良層等−
前記密着改良層は、本発明の電子写真用受像シートにおいて、支持体及びトナー受像層の密着性を改良する目的で、形成するのが好ましい。密着改良層には、前述の各種の添加剤を配合することができ、特に架橋剤を配合するのが好ましい。また、本発明の電子写真用受像シートには、トナーの受容性を改良するため、該密着改良層及びトナー受像層の間に、更にクッション層等を設けるのが好ましい。
【０１６５】
−中間層−
前記中間層は、例えば、支持体及び密着改良層の間、密着改良層及びクッション層の間、クッション層及びトナー受像層の間、トナー受像層及び保存性改良層との間等に形成することができる。もちろん、支持体、トナー受像層、及び、中間層からなる電子写真用受像シートの場合には、中間層は、例えば、支持体及びトナー受像層の間に存在させることができる。
【０１６６】
なお、本発明の前記電子写真用受像シートの厚みとしては、特に制限はなく、目的に応じて適宜選定することができるが、例えば、５０〜３５０μｍが好ましく、１００〜２８０μｍがより好ましい。
【０１６７】
（トナー）
本発明の電子写真用受像シートは、印刷又は複写の際に、トナー受像層にトナーを受容させて使用される。
前記トナーは、結着樹脂と着色剤とを少なくとも含有し、必要に応じて離型剤、その他の成分を含有する。
【０１６８】
−トナー 結着樹脂−
前記結着樹脂としては、例えば、スチレン、パラクロルスチレンなどのスチレン類；ビニルナフタレン、塩化ビニル、臭化ビニル、弗化ビニル、酢酸ビニル、プロピオン酸ビニル、ベンゾエ酸ビニル、酪酸ビニルなどのビニルエステル類；アクリル酸メチル、アクリル酸エチル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ドデシル、アクリル酸ｎ−オクチル、アクリル酸２−クロルエチル、アクリル酸フェニル、α−クロルアクリル酸メチル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチルなどのメチレン脂肪族カルボン酸エステル類；アクリロニトリル、メタクリルロニトリル、アクリルアミドなどのビニルニトリル類；ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテルなどのビニルエーテル類；Ｎ−ビニルピロール、Ｎ−ビニルカルバゾール、Ｎ−ビニルインドール、Ｎ−ビニルピロリドンなどのＮ−ビニル化合物類；メタクリル酸、アクリル酸、桂皮酸などのビニルカルボン酸類などビニル系モノマーの単独重合体やその共重合体、更には各種ポリエステル類を使用することができ、各種ワックス類を併用することも可能である。
これらの樹脂の中で、特に本発明のトナー受像層に用いたものと同一系統の樹脂を用いるのが好ましい。
【０１６９】
−トナー 着色剤−
前記着色剤としては、通常トナーに用いられているものを制限なく使用することができ、例えば、カーボンブラック、クロムイエロー、ハンザイエロー、ベンジジンイエロー、スレンイエロー、キノリンイエロー、パーメネントオレンジＧＴＲ、ピラゾロンオレンジ、バルカンオレンジ、ウオッチヤングレッド、パーマネントレッド、ブリリアンカーミン３Ｂ、ブリリアンカーミン６Ｂ、デイポンオイルレッド、ピラゾロンレッド、リソールレッド、ローダミンＢレーキ、レーキレッドＣ、ローズベンガル、アニリンブルー、ウルトラマリンブルー、カルコオイルブルー、メチレンブルークロライド、フタロシアニンブルー、フタロシアニングリーン、マラカイトグリーンオクサレレートなどの種々の顔料が挙げられる。また、アクリジン系、キサンテン系、アゾ系、ベンゾキノン系、アジン系、アントラキノン系、チオインジコ系、ジオキサジン系、チアジン系、アゾメチン系、インジコ系、チオインジコ系、フタロシアニン系、アニリンブラック系、ポリメチン系、トリフェニルメタン系、ジフェニルメタン系、チアジン系、チアゾール系、キサンテン系などの各種染料などが挙げられる。これら着色剤は１種単独で使用してもよいし、複数種類を併せて使用してもよい。
着色剤の含有量は、２〜８質量％の範囲が好ましい。着色剤の含有量が２質量％以上であれば着色力が弱くなることもなく、一方、８質量％以下であれば、透明性が損なわれることもないので好ましい。
【０１７０】
−トナー 離型剤−
前記離型剤としては、原理的には、公知のワックス全てが使用可能であるが、比較的低分子量の高結晶性ポリエチレンワックス、フィッシャートロプシュワックス、アミドワックス、ウレタン化合物など窒素を含有する極性ワックスなどが特に有効である。ポリエチレンワックスの分子量は１０００以下が好ましく、３００〜１０００がより好ましい。
【０１７１】
前記ウレタン結合を有する化合物は、低分子量であっても極性基による凝集力の強さにより、固体状態を保ち、融点も分子量のわりには高く設定できるので好適である。分子量の好ましい範囲は３００〜１０００である。原料は、ジイソシアン酸化合物類とモノアルコール類との組み合わせ、モノイソシアン酸とモノアルコールとの組み合わせ、ジアルコール類とモノイソシアン酸との組み合わせ、トリアルコール類とモノイソシアン酸との組み合わせ、トリイソシアン酸化合物類とモノアルコール類との組み合わせなど、種々の組み合わせを選択することができが、高分子量化させないために、多官能基と単官能基の化合物を組み合わせることが好ましく、また等価の官能基量となるようにすることが重要である。
【０１７２】
具体的な、原料化合物のうちモノイソシアン酸化合物としては、例えば、イソシアン酸ドデシル、イソシアン酸フェニル及びその誘導体、イソシアン酸ナフチル、イソシアン酸ヘキシル、イソシアン酸ベンジル、イソシアン酸ブチル、イソシアン酸アリルなどが挙げられる。
ジイソシアン酸化合物としては、ジイソシアン酸トリレン、ジイソシアン酸４、４’ジフェニルメタン、ジイソシアン酸トルエン、ジイソシアン酸１、３−フェニレン、ジイソシアン酸ヘキサメチレン、ジイソシアン酸４−メチル−ｍ−フェニレン、ジイソシアン酸イソホロンなどが挙げられる。
モノアルコールとしては、メタノール、エタノール、プロパノール、ブタノール、ペンタノール、ヘキサノール、ヘプタノールなど極く一般的なアルコール類を使用することが可能である。
原料化合物のうちジアルコール類としては、エチレングリコール、ジエチレングリコール、トリエチレングリコール、トリメチレングリコールなど多数のグリコール類；トリアルコール類としては、トリメチロールプロパン、トリエチロールプロパン、トリメタノールエタンなどが使用可能であるが、必ずしもこの範囲に限定されない。
【０１７３】
これらのウレタン化合物類は、通常の離型剤のように、混練時に樹脂や着色剤とともに混合して、混練粉砕型トナーとしても使用できる。また、前記の乳化重合凝集溶融法トナーに用いる場合には、水中にイオン性界面活性剤や高分子酸や高分子塩基などの高分子電解質とともに分散し、融点以上に加熱してホモジナイザーや圧力吐出型分散機で強い剪断をかけて微粒子化し、１μｍ以下の離型剤粒子分散液を調製し、樹脂粒子分散液、着色剤分散液などとともに用いることができる。
【０１７４】
−トナー その他の成分−
また、本発明のトナーには、内添剤、帯電制御剤、無機微粒子等のその他の成分を配合することができる。内添剤としては、フェライト、マグネタイト、還元鉄、コバルト、ニッケル、マンガン等の金属、合金、又はこれら金属を含む化合物などの磁性体を使用することができる。
【０１７５】
前記帯電制御剤としては、４級アンモニウム塩化合物、ニグロシン系化合物、アルミや、鉄、クロムなどの錯体からなる染料、トリフェニルメタン系顔料など通常使用される種々の帯電制御剤を使用することができる。なお、凝集、溶融時の安定性に影響するイオン強度の制御や、廃水汚染を減少する観点から水に溶解しにくい材料が好ましい。
【０１７６】
前記無機微粒子としては、シリカ、アルミナ、チタニア、炭酸カルシウム、炭酸マグネシウム、リン酸三カルシウムなど、通常、トナー表面の外添剤を全て使用で、それらをイオン性界面活性剤や高分子酸、高分子塩基で分散して使用することが好ましい。
【０１７７】
更に、乳化重合、シード重合、顔料分散、樹脂粒子分散、離型剤分散、凝集、更には、それらの安定化などに界面活性剤を用いることができる。例えば、硫酸エステル塩系、スルホン酸塩系、リン酸エステル系、せっけん系等のアニオン界面活性剤、アミン塩型、４級アンモニウム塩型等のカチオン系界面活性剤、また、ポリエチレングリコール系、アルキルフェノールエチレンオキサイド付加物系、多価アルコール系等の非イオン性界面活性剤を併用することも効果的である。その際の分散手段としては、回転せん断型ホモジナイザーやメデイアを有するボールミル、サンドミル、ダイノミルなどの一般的なものが使用可能である。
【０１７８】
なお、前記トナーには、必要に応じて更に外添剤を添加してもよい。前記外添剤としては、無機粉末及び有機粒子等が挙げられる。前記無機粒子としては、ＳｉＯ_２、ＴｉＯ_２、Ａｌ_２Ｏ_３、ＣｕＯ、ＺｎＯ、ＳｎＯ_２、Ｆｅ_２Ｏ_３、ＭｇＯ、ＢａＯ、ＣａＯ、Ｋ_２Ｏ、Ｎａ_２Ｏ、ＺｒＯ_２、ＣａＯ・ＳｉＯ_２、Ｋ_２Ｏ・（ＴｉＯ_２）_ｎ、Ａｌ_２Ｏ_３・２ＳｉＯ_２、ＣａＣＯ_３、ＭｇＣＯ_３、ＢａＳＯ_４、ＭｇＳＯ_４等を例示することができる。また、前記有機粒子としては、脂肪酸又はその誘導体や、これ等の金属塩等の粉末、フッ素系樹脂、ポリエチレン樹脂、アクリル樹脂等の樹脂粉末を用いることができる。これらの粉末の平均粒径は、例えば、０．０１〜５μｍが好ましく、０．１〜２μｍがより好ましい。
【０１７９】
前記トナーの製造方法は、特に制限されないが、（ｉ）樹脂粒子を分散させてなる分散液中で凝集粒子を形成し凝集粒子分散液を調製する工程、（ｉｉ）前記凝集粒子分散液中に、微粒子を分散させてなる微粒子分散液を添加混合して前記凝集粒子に前記微粒子を付着させて付着粒子を形成する工程、及び（ｉｉｉ）前記付着粒子を加熱し融合してトナー粒子を形成する工程、とを含むトナーの製造方法により製造することが好ましい。
【０１８０】
−トナー物性等−
本発明のトナーの体積平均粒子径は０．５μｍ以上１０μｍ以下が好ましい。
前記トナーの体積平均粒子径が小さすぎると、トナーのハンドリング（補給性、クリーニング性、流動性等）に悪影響が生じる場合があり、また、粒子生産性が低下する場合がある。一方、トナーの体積平均粒子径が大きすぎると、粒状性、転写性に起因する画質、解像度に悪影響を与える場合がある。
また、本発明のトナーは、前記トナーの体積平均粒子径範囲を満たし、かつ体積平均粒度分布指数（ＧＳＤｖ）は１．３以下が好ましい。
前記体積平均粒度分布指数（ＧＳＤｖ）と数平均粒度分布指数（ＧＳＤｎ）との比（ＧＳＤｖ／ＧＳＤｎ）は０．９５以上が好ましい。
また、本発明のトナーは、前記トナーの体積平均粒子径範囲を満たし、かつ下記式で表される形状係数の平均値は１．００〜１．５０が好ましい。
形状係数＝（π×Ｌ^２）／（４×Ｓ）
（但し、Ｌはトナー粒子の最大長、Ｓはトナー粒子の投影面積を示す。）
トナーが上記条件を満たす場合には、画質、特に、粒状性、解像度に効果があり、また、転写に伴う抜けやブラーが生じにくく、平均粒径が小さくなくてもハンドリング性に悪影響が出にくくなる。
【０１８１】
なお、トナー自体の１５０℃における貯蔵弾性率Ｇ’（角周波数１０ｒａｄ／ｓｅｃで測定）は、１０〜２００Ｐａであることが、定着工程での画質向上とオフセット性の防止の面から適当である。
【０１８２】
（画像形成方法）
本発明の画像形成方法は、加熱加圧処理として、加熱加圧手段と、冷却手段と、冷却剥離部とを有する冷却剥離式のベルト定着型平滑化処理機を用いることが好適である。
前記加熱加圧手段により、前記画像形成層における熱可塑性樹脂の軟化点以上の温度に加熱加圧し、冷却した後、前記加熱加圧手段におけるベルト部材から剥離することが好ましい（冷却剥離処理）。
前記冷却剥離方式のベルト型平滑化処理機の加熱加圧手段としては、特に制限されないが、例えば、加熱ローラと加圧ローラと無端ベルトとの組み合わせなどが挙げられる。前記冷却手段としては、特に制限されないが、例えば、冷気を送風可能であり、冷却温度等を調節可能である冷却装置、ヒートシンク、などが用いられる。
【０１８３】
前記画像形成材料を前記冷却剥離方式のベルト型平滑化処理機の加熱加圧手段に接触させる際には、加圧することが好ましい。この加圧の方法としては、特に制限はないが、ニップ圧を印加するのが好ましい。前記ニップ圧としては、耐水性、表面平滑性に優れ、良好な光沢を有する画像形成を行う観点から、１〜１００ｋｇ／ｃｍ^２が好ましく、５〜３０ｋｇ／ｃｍ^２がより好ましい。また、加熱加圧手段における加熱は、画像形成層における熱可塑性樹脂の軟化点以上の温度であり、用いる熱可塑性樹脂に応じて異なるが、通常、８０℃以上２００℃以下が好ましい。前記冷却手段における冷却温度は、画像形成層における熱可塑性樹脂層が十分に固化する８０℃以下の温度が好ましく、２０〜８０℃がより好ましい。
【０１８４】
前記定着ベルトの表面は、シリコーンゴム、フッ素ゴム、シリコーン樹脂、フッ素樹脂からなる群より選択される少なくとも１種以上からなる薄膜が形成されることが好ましい。中でも、ベルト部材の表面に均一な厚さのフルオロカーボンシロキサンゴム製の層を設ける態様、前記ベルト部材の表面に均一な厚さのシリコーンゴム製の層を有し、かつ該シリコーンゴム層の表面に均一な厚さのフルオロカーボンシロキサンゴム製の層を設ける態様が好ましい。
【０１８５】
前記フルオロカーボンシロキサンゴムとしては、主鎖にパーフルオロアルキルエーテル基及び／又はパーフルオロアルキル基を有するものが好ましい。
このようなフルオロカーボンシロキサンゴムとしては、（Ａ）下記一般式（１）のフルオロカーボンシロキサンを主成分とし、脂肪族不飽和基を有するフルオロカーボンポリマー、（Ｂ）１分子中に２個以上の≡ＳｉＨ基を含有し、上記フルオロカーボンシロキサンゴム組成物中の脂肪族不飽和基量に対して上記≡ＳｉＨ基の含有量が１〜４倍モル量であるオルガノポリシロキサン及び／又はフルオロカーボンシロキサン、（Ｃ）充填剤、（Ｄ）有効量の触媒を含有するフルオロカーボンシロキサンゴム組成物の硬化物が好適に用いられる。
【０１８６】
前記（Ａ）成分のフルオロカーボンポリマーは、下記一般式（１）で示される繰り返し単位を有するフルオロカーボンシロキサンを主成分とし、脂肪族不飽和基を有するものである。
【０１８７】
【化１】

【０１８８】
ここで、上記式（１）において、Ｒ^１０は非置換又は置換の好ましくは炭素数１〜８の一価炭化水素基であり、好ましくは炭素数１〜８のアルキル基又は炭素数２〜３のアルケニル基であり、特にメチル基であることが好ましい。ａ，ｅはそれぞれ０又は１、ｂ，ｄはそれぞれ１〜４の整数、ｃは０〜８の整数である。また、ｘは１以上の整数、好ましくは１０〜３０である。
【０１８９】
このような（Ａ）成分としては、下記式（２）で示すものを挙げることができる。
【０１９０】
【化２】

【０１９１】
前記（Ｂ）成分において、≡ＳｉＨ基を有するオルガノポリシロキサンとしては、ケイ素原子に結合した水素原子を分子中に少なくとも２個有するオルガノハイドロジェンポリシロキサンを挙げることができる。
【０１９２】
また、本発明で用いるフルオロカーボンシロキサンゴム組成物においては、（Ａ）成分のフルオロカーボンポリマーが脂肪族不飽和基を有するものであるときには、硬化剤として上述したオルガノハイドロジェンポリシロキサンを使用することができる。即ち、この場合には、フルオロカーボンシロキサン中の脂肪族不飽和基と、オルガノハイドロジェンポリシロキサン中のケイ素原子に結合した水素原子との間で生ずる付加反応によって硬化物が形成されるものである。
【０１９３】
このようなオルガノハイドロジェンポリシロキサンとしては、付加硬化型のシリコーンゴム組成物に使用される種々のオルガノハイドロジェンポリシロキサンを使用することができる。
【０１９４】
上述したオルガノハイドロジェンポリシロキサンは、一般にその≡ＳｉＨ基の数が、（Ａ）成分のフルオロカーボンシロキサン中の脂肪族不飽和炭化水素基１個に対して、少なくとも１個、特に１〜５個となるような割合で配合することが好適である。
【０１９５】
また、≡ＳｉＨ基を有するフルオロカーボンとしては、上記式（１）の単位又は式（１）においてＲ^１０がジアルキルハイドロジェンシロキシ基であり、かつ末端がジアルキルハイドロジェンシロキシ基又はシリル基等の≡ＳｉＨ基であるものが好ましく、下記式（３）で示すものを挙げることができる。
【０１９６】
【化３】

【０１９７】
前記（Ｃ）成分の充填剤としては、一般的なシリコーンゴム組成物に使用されている種々の充填剤を用いることができる。例えば、煙霧質シリカ、沈降性シリカ、カーボン粉末、二酸化チタン、酸化アルミニウム、石英粉末、タルク、セリサイト及びベントナイト等の補強性充填剤、アスベスト、ガラス繊維、有機繊維等の繊維質充填剤などを例示することができる。
【０１９８】
前記（Ｄ）成分の触媒としては、付加反応用触媒として公知とされている塩化白金酸、アルコール変性塩化白金酸、塩化白金酸とオレフィンとの錯体、白金黒又はパラジウムをアルミナ、シリカ、カーボンなどの担体に担持したもの、ロジウムとオレフィンとの錯体、クロロトリス（トリフェニルフォスフィン）ロジウム（ウィルキンソン触媒）、ロジウム（ＩＩＩ）アセチルアセトネートなどのような周期律表第ＶＩＩＩ族元素又はその化合物が例示されるが、これらの錯体はアルコール系、エーテル系、炭化水素などの溶剤に溶解して用いることが好ましい。
【０１９９】
本発明で用いるフルオロカーボンシロキサンゴム組成物においては、耐薬品性を向上させるという本発明の目的を損なわない範囲において、種々の配合剤を添加することができる。例えば、ジフェニルシランジオール、低重合度の分子鎖末端水酸基封鎖ジメチルポリシロキサン、ヘキサメチルジシラザン等の分散剤、酸化第一鉄、酸化第二鉄、酸化セリウム、オクチル酸鉄等の耐熱性向上剤、顔料等の着色剤等を必要に応じて配合することができる。
【０２００】
前記本発明のベルト部材は、耐熱性樹脂製又は金属製のベルト本体の表面を上記フルオロカーボンシロキサンゴム組成物で被覆し、加熱硬化することによって得られるが、必要に応じて更に、ｍ−キシレンヘキサフロライド、ベンゾトリフロライド等の溶剤で希釈して塗工液とし、スプレーコート、ディップコート及びナイフコート等の一般的なコーティング法によって塗布することができる。また、加熱硬化の温度、時間は適宜選定することができ、通常温度１００〜５００℃、時間５秒〜５時間の範囲でベルト本体の種類及び製造方法などに応じて選択される。
【０２０１】
前記ベルト部材の表面に形成するフルオロカーボンシロキサンゴム層の厚さは特に限定されるものではないが、通常２０〜５００μｍが好ましく、４０〜２００μｍがより好ましい。
【０２０２】
前記ベルト部材の表面粗さ〔算術平均粗さ（Ｒａ）〕としては、特に、表面平滑性に優れ、良好な光沢を有する画像形成を行える点で、２０μｍ以下が好ましく、５μｍ以下がより好ましく、１μｍ以下が更に好ましい。なお、算術平均粗さは、ＪＩＳ Ｂ ０６０１、Ｂ ０６５１、Ｂ ０６５２に基づいて測定することができる。
【０２０３】
本発明の電子写真用受像シートに画像を形成する方法は、定着ベルトを使用した電子写真方法であれば、特に制限はなく、通常の電子写真法であれば、いずれも適用することができる。
例えば、本発明の電子写真用受像シートには、カラー画像を好ましく形成することができる。カラー画像の形成は、フルカラー画像を形成し得る電子写真装置を用いて行うことができる。通常の電子写真装置は、受像シート搬送部と、潜像形成部と、潜像形成部に近接して配設されている現像部とがあり、機種によっては、装置本体の中央に潜像形成部と受像シート搬送部に近接してトナー像中間転写部を有している。
【０２０４】
更に、画質の向上を図るための方法として、静電転写或いはバイアスローラ転写に代わって、或いは併用して、粘着転写又は熱支援型の転写方式が知られている。例えば、特開昭６３−１１３５７６号公報及び特開平５−３４１６６６号公報にはその具体的な構造が記載されている。特に熱支援型転写方式の中間転写ベルトを用いた方法は、小粒径のトナーを使用する場合には好ましい。
【０２０５】
本発明の画像形成方法によれば、定着オイルのないオイルレス機を使用しても、電子写真用受像シート及びトナーの剥離性、或いは電子写真用受像シート及びトナー成分のオフセットを防止でき、安定した給紙を実現できると共に、これまでにない良好な光沢性を有し、写真感覚に富む、良好な画像を実現できる。
【０２０６】
図１及び図３は、ベルト定着型平滑化処理機の一例を示し、特に図１の冷却剥離式のベルト式処理機（エンドレスプレス）において、処理部１は、ベルト２と、加熱ローラ３と、加圧ローラ４と、テンションローラ５と、クリーニングローラ６と、冷却装置７と、搬送ローラ８と、を備えている。
前記ベルト２の内側には、ベルト２と一対のテンションローラ５とが配置されている。前記ベルト２は、加熱ローラ３と、加熱ローラ３と離れた位置に配された一対のテンションローラ５とにより、回転可能に張設されている。前記加圧ローラ４は、ベルト２と当接して加熱ローラ３と対向して配置されている。加圧ローラ４とベルト２との間は、加圧ローラ４と加熱ローラ３とにより加圧されており、ニップ部が形成されている。前記冷却装置７は、ベルト２の内側であって、ベルト２の回転方向における、上流側に位置する加熱ローラ３と下流側に位置するテンションローラ５との間に配置されている。搬送ローラ８は、ベルト２を介して冷却装置７と対向するようにして２個配置されている。ここでは、２個の搬送ローラの間隔は、前記ニップ部と搬送ローラ８の１つとの距離、テンションローラ５と搬送ローラ８の他の１つとの距離と、略同じ長さである。前記クリーニングローラ６は、ベルト２を介して、加熱ローラ３における加圧ローラ４と対向する側とは反対側と対向して配置されている。クリーニングローラ６とベルト２との間は、クリーニングローラ６と加熱ローラ３とにより加圧されている。加熱ローラ３と、加圧ローラ４と、テンションローラ５と、クリーニングローラ６と、搬送ローラ８とは、互いに連動して回転し、ベルト２を回転させることができる。
【０２０７】
また、図３に示したベルト定着型平滑化処理機は、例えば、図２に示した電子写真装置（例えば、富士ゼロックス製フルカラーレーザープリンター（ＤＣＣ−５００））のベルト状定着部として改造して用いることができる。
図２中、１００は画像形成装置、３７は感光体ドラム、９は現像装置、３１は中間転写ベルト、１６は記録シート、２５はベルト状定着部、をそれぞれ示す。図３は、上記図２の画像形成装置１００の内部に配設されるベルト式定着部２５を示すものである。
このベルト式定着装置２５は、図３に示すように、加熱ロール７１と、該加熱ロール７１を含む剥離ロール７４、テンションロール７５により回動可能に支持された無端ベルト７３と、前記加熱ロール７１に無端ベルト７３を介して圧接する加圧ロール７２とを備えている。
また、前記無端ベルト７３の内面側には、加熱ロール７１と剥離ロール７４との間に、該無端ベルト７３を強制的に冷却する冷却用のヒートシンク７７が配設されており、この冷却用ヒートシンク７７によって電子写真用受像シートの冷却及びシートの搬送を行う冷却・シート搬送部が構成されている。
【０２０８】
そして、前記ベルト式定着装置２５では、図３に示すように、表面にカラートナー画像が転写・定着された電子写真用転写シートが、加熱ロール７１と当該加熱ロール７１に無端ベルト７３を介して圧接する加圧ロール７２との圧接部（ニップ部）に、カラートナー画像が加熱ロール７１側に位置するようにして導入され、上記加熱ロール７１と加圧ロール７２との圧接部を通過する間に、カラートナー画像Ｔが電子写真用転写シート上に加熱溶融されて定着される。
【０２０９】
その後、前記加熱ロール７１と加圧ロール７２との圧接部において、例えば、トナーが実質的に１２０〜１３０℃程度の温度に加熱され、溶融されて、カラートナー画像が受像層に定着された電子写真用受像シートは、その表面の受像層が無端ベルト７３の表面に密着したまま状態で、当該無端ベルト７３と共に搬送される。その間、上記無端ベルト７３は、冷却用のヒートシンク７７によって強制的に冷却され、カラートナー画像及び受像層が冷却して固化した後、剥離ロール７４によって電子写真用受像シート自身の腰（剛性）によって剥離される。
【０２１０】
なお、剥離工程が終了した後の無端ベルト７３の表面は、クリーナ（図示せず）によって残留トナー等が除去され、次の定着工程に備えるようになっている。
【０２１１】
本発明の電子写真用受像シートに画像を形成する方法は、定着ベルトを使用した電子写真方法であれば、上記方法に制限されるものではない。通常の電子写真法であれば、いずれも適用することができる。
例えば、本発明の電子写真用受像シートには、カラー画像を好ましく形成することができる。カラー画像の形成は、フルカラー画像を形成し得る電子写真装置を用いて行うことができる。通常の電子写真装置は、受像シート搬送部と、潜像形成部と、潜像形成部に近接して配設されている現像部とがあり、機種によっては、装置本体の中央に潜像形成部と受像シート搬送部に近接してトナー像中間転写部を有している。
【０２１２】
更に、画質の向上を図るための方法として、静電転写或いはバイアスローラ転写に代わって、或いは併用して、粘着転写又は熱支援型の転写方式が知られている。例えば、特開昭６３−１１３５７６号公報及び特開平５−３４１６６６号公報にはその具体的な構造が記載されている。特に熱支援型転写方式の中間転写ベルトを用いた方法は、小粒径のトナーを使用する場合には好ましい。
【０２１３】
本発明の画像形成方法によれば、定着オイルのないオイルレス機を使用しても、電子写真用受像シート及びトナーの剥離性、或いは電子写真用受像シート及びトナー成分のオフセットを防止でき、安定した給紙を実現できると共に、これまでにない良好な光沢性を有し、写真感覚に富む、良好な画像を実現できる。
【０２１４】
【実施例】
以下、本発明の実施例について説明するが、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。
なお、以下の実施例及び比較例において、「％」及び「部」は、それぞれ「質量％」及び「質量部」を表す。
【０２１５】
（実施例１〜６及び比較例１〜５）
−支持体の作製−
ＬＢＫＰ（広葉樹の漂白パルプ）からなる木材パルプをダブルディスクリファイナーによりカナディアンフリーネス（、Ｃ．Ｆ．Ｓ．）３００ｍｌまで叩解した。このパルプ材料１００部に対して、カチオン性澱粉を１．０部、アルキルケテンダイマー０．５部、エポキシ化脂肪酸アミド０．５部、ポリアミンポリアミドエピクロロヒドリン０．３部、高級脂肪酸エステル０．０３部、及びコロイドダルシリカ０．０２部を添加し、長網抄紙機により坪量１６５／ｍ^２の原紙をカレンダーを用いて厚みを１５５〜１７５μｍ（密度１．０６〜０．９４ｇ／ｃｍ^３）に調整した原紙を得た。
【０２１６】
この原紙を毎分１５０ｍ／分で走行させ、裏面にコロナ放電処理した後、低密度ポリエチレン（密度０．９２４ｇ／ｃｍ^３ ＭＩ＝３ｇ／１０ｍｉｎ）１０部、及び高密度ポリエチレン（密度０．９６６ｇ／ｃｍ^３ ＭＩ＝１１ｇ／１０ｍｉｎ）９０部からなる１０μｍの層と、低密度ポリエチレン（密度０．９２２ｇ／ｃｍ^３ ＭＩ＝５ｇ／１０ｍｉｎ）５０部、及び高密度ポリエチレン（密度０．９７０ｇ／ｃｍ^３ ＭＩ＝２０ｇ／１０ｍｉｎ）５０部からなる１５μｍの最外層とをコートハンガータイプの二層同時共押出用ダイを使用して溶融押出し、直後に、表１に示すように中心線平均粗さ（Ｒａ）及び冷却温度を適宜調整したマット面を有する冷却ロールを用いて型付けして無光沢樹脂層を設けた。
【０２１７】
更に、前記原紙の表面にコロナ放電処理した後、低密度ポリエチレン（密度０．９２０ｇ／ｃｍ^３ ＭＩ＝５ｇ／１０ｍｉｎ）３７．６部にＴｉＯ_２６０部及びステアリン酸亜鉛２．４部を練りこんだマスターバッチ１０部と、青み顔料を練りこんだマスターバッチ４部と、低密度ポリエチレン（密度０．９１８ｇ／ｃｍ^３ ＭＩ＝８ｇ／１０ｍｉｎ）８６部とからなる１４μｍの層と、低密度ポリエチレン（密度０．９２０ｇ／ｃｍ^３ ＭＩ＝５ｇ／１０ｍｉｎ）３７．６部にＴｉＯ_２６０部及びステアリン酸亜鉛２．４部を練りこんだマスターバッチ３３部と、蛍光増白剤を練りこんだマスターバッチ５部と、青み顔料を練りこんだマスターバッチ４部とからなる１６μｍの最外層をコートハンガータイプの二層同時共押出用ダイを使用して溶融押出し、直後に、表２に示すように中心線平均粗さ（Ｒａ）及び冷却温度を適宜調整した微細な粗面（微細マット面）を有する冷却ロールを用いて型付けして光沢樹脂層を設けた。
以上のようにして、原紙の表面及び裏面に、それぞれ光沢樹脂層、無光沢樹脂層を有する実施例１〜６及び比較例１〜５の支持体を得た。
【０２１８】
得られた各支持体の無光沢樹脂層（裏面）及び光沢樹脂層（表面）について、下記方法により、ベック平滑度、中心線平均粗さ（Ｒａ）、局部山頂平均間隔（Ｓ）を測定した。結果を表１及び表２に示す。
【０２１９】
＜ベック平滑度＞
熊谷理機工業株式会社製ベック平滑度試験器を用いて、ベック平滑度を測定した。なお、ＪＩＳ Ｐ８１１９に記載の紙及び板紙のベック平滑度試験に基づいて評価した。
【０２２０】
＜表面粗さ＞
株式会社小坂研究所製 万能表面形状測定機Ｓｕｒｆｃｏｒｄｅｒ ＳＥ−３Ｃを用いて、下記の条件で中心線平均粗さ（Ｒａ）及び局部山頂平均間隔（Ｓ）を測定した。なお、中心線平均粗さ（Ｒａ）及び局部山頂平均間隔（Ｓ）の定義はＪＩＳ Ｂ０６０１における表面粗さの定義及び表示による。
・中心線平均粗さ（Ｒａ）のカットオフ値（λｃ）＝０．８ｍｍ、測定長さ（Ｌｎ）＝４ｍｍ
・局部山頂平均間隔（Ｓ）の基準長さ（Ｌ）＝０．０８ｍｍ、評価長さ（Ｌｎ）＝０．４ｍｍ
【０２２１】
【表１】
支持体（裏面）

【０２２２】
【表２】
支持体（表面）

【０２２３】
−バック層の形成−
反応性乳化剤（アデカリアソープＳＥ−１０Ｎ、旭電化工業（株）製）の存在下で、芳香族系エチレン性不飽和単量体としてスチレン６２部、エチレン性不飽和単量体としてアクリル酸８部、他のエチレン性不飽和単量体としてアクリル酸２−エチルヘキシル３０部を乳化重合し、スチレン／アクリル酸エステルの水系分散体を得た。
得られたスチレン／アクリル酸エステルの水系分散体１４部、ポリスチレンスルホン酸のナトリウム塩（ケミスタットＳＡ９、三洋化成株式会社製）からなる水溶性高分子化合物を４部、コロイド状シリカを６部、及びメタノール２０部とを混合し、水を加えて全量を１００部とした水性の塗布液を前記支持体の裏面（無光沢樹脂層）上に、乾燥後の塗布厚みが０．２５μｍとなるようにワイヤーコータ−にて塗布し、バック層を形成した。
【０２２４】
−中間層の形成−
前記支持体の表面側に、下記の中間層組成物を、乾燥後の塗布厚みが５μｍとなるようにワイヤーコーターにて塗布乾燥した。
−−中間層組成物−−
・水分散アクリル樹脂・・・・・・・・・・・・・１００部
（星光化学工業（株）製、ハイロースＨＥ−１３３５（固形分４５％））
・界面活性剤・・・・・・・・・・・・・・・・・２部
（日本油脂（株）製、ラピゾールＢ−９０（固形分１０％））
・イオン交換水・・・・・・・・・・・・・・・・３０部
【０２２５】
−トナー受像層の形成−
前記中間層上に、下記のトナー受像層用組成物を、乾燥後の厚みが７μｍとなるようにワイヤーコーターにて塗布し１００℃で５分間乾燥させて、実施例１〜６及び比較例１〜５の電子写真用受像シートを作製した。
−−トナー受像層用組成物−−
・水分散ポリエステル樹脂・・・・・・・・・・１００部
（ユニチカ（株）エリーテルＫＺＡ−１４４９（固形分３０％）、流動開始温度（１００．４(℃)）
・離型剤・・・・・・・・・５部
（カルナバワックス、中京油脂（株）製、セロゾール５２４）
・白色顔料（ＴｉＯ_２）水分散液・・・・７．５部
〔ＴｉＯ_２（タイぺークＲ７８０−２（石原産業製））及び高分子分散剤による水分散液〕
・界面活性剤・・・８部
（日本油脂（株）製、ラピゾールＤ−３３７（固形分１０％））
・帯電防止剤・・・７部
（日本油脂（株）製、ラピゾールＢ−９０（固形分１０％））
【０２２６】
得られた実施例１〜６及び比較例１〜５の各電子写真用受像シートについて、上記同様の方法によりベック平滑度、中心線平均粗さ（Ｒａ）、局部山頂平均間隔（Ｓ）を測定すると共に、下記方法により、画質（光沢性）、裏面ザラツキ感、走行性、及び耐接着性の評価を行った。結果を表３及び表４に示す。
【０２２７】
＜画質（光沢性）＞
図２に示した富士ゼロックス製フルカラーレーザープリンター（ＤＣＣ−５００）の定着部を、図３に示したベルト状定着部に改造した画像形成装置（ベルト及び冷却条件は下記のとおりである）を用い、Ｂ／Ｗ条件で濃度を６段階（０、２０、４０、６０、８０、１００％）に１０ｃｍ四方で絵だしした。この６段階部分を、ＪＩＳ Ｚ ８７４１に準拠して、デジタル変角光沢度計（スガ試験機製、ＵＧＶ−５Ｄ）を用いて、２０度測定で測定し、その最小値を記録した。光沢度は７５以上が好ましい。
−ベルト−
ベルトの支持体：ポリイミド（ＰＩ）フイルム、幅＝５０ｃｍ、厚み＝８０μｍ
ベルトの離型層素材：フルオロカーボンシロキサンゴム前駆体であるＳＩＦＥＬ６１０を加硫硬化してフルオロカーボンシロキサンゴム５０μｍの膜厚に形成した。
−冷却条件−
冷却器：ヒートシンク長＝８０ｍｍ
速度：５３ｍｍ／ｓｅｃ
【０２２８】
＜裏面ザラツキ感＞
得られた各電子写真用受像シートの裏面のザラツキ感を目視観察し、下記基準により評価した。
〔評価基準〕
１：裏面ザラツキ感なし
２：裏面ザラツキ感あるも気にならず問題なし
３：裏面ザラツキあり、やや問題となる
４：裏面のザラツキが強く、問題となる
【０２２９】
＜走行性＞
画像形成装置（同上）で連続１００枚給紙した時の給紙不良、ジャミング、及び集積不良のいずれかが生じた合計枚数をカウントした。走行性は２以下が好ましい。
【０２３０】
＜耐接着性＞
得られた各電子写真用受像シートを４０℃、８０％ＲＨで２４時間調整した後、受像面を対向させて重ね合せ、３．５ｃｍ四方×５００ｇの荷重を加え、同一環境下で７日間設置した後、サンプルを引き離す際の状態を下記基準により評価した。耐接着性は２以下が好ましい。
〔評価基準〕
１：剥離音、接着跡ともになし。
２：軽微な剥離音又は接着跡がある。
３：接着跡が１／４未満である。
４：１／４〜１／２未満が接着している。
５：１／２以上が接着している。
【０２３１】
【表３】
電子写真用受像シート

【０２３２】
【表４】

【０２３３】
【発明の効果】
本発明によると、良好な光沢性を有し、写真感覚に富む、良好な画像が得られると共に、粉落ち防止、表面のザラツキ感防止、走行性、及び耐接着性のすべてを向上させることができる電子写真用受像シートを提供できる。
【図面の簡単な説明】
【図１】図１は、本発明の冷却剥離式のベルト定着型平滑化処理機の一例を示す概略図である。
【図２】図２は、実施例で用いた電子写真装置の一例を示す概略図である。
【図３】図３は、実施例で用いた冷却剥離式のベルト定着型平滑化処理機の一例を示す概略図である。
【符号の説明】
１ 処理部
２ ベルト
３ 加熱ローラ
４ 加圧ローラ
５ テンションローラ
６ クリーニングローラ
７ 冷却装置
８ 搬送ローラ
１０ 電子写真用受像シート
２５ ベルト式定着装置
７１ 加熱ロール
７２ 加圧ロール
７４ 剥離ロール
７５ テンションロール
７３ 無端ベルト
７７ 冷却ヒートシンク
１００ 画像形成装置[0001]
In particular, the present invention provides a good image having good glossiness and richness in photographic sense, and also improves all of prevention of powder falling, surface roughness, running performance, and adhesion resistance. The present invention relates to a support for an electrophotographic image receiving sheet and a method for producing the same, and an electrophotographic image receiving sheet and an image forming method.
[0002]
[Prior art]
Conventionally, a resin-coated support (double-sided polyolefin resin-coated paper) used for silver-salt photographic prints has been used as a support for an electrophotographic image-receiving sheet in order to realize high-quality images of silver-salt photographic-like in electrophotography. It is used. As a result, an electrophotographic image-receiving sheet having high smoothness, glossiness and flatness and excellent in image quality and handling is obtained.
[0003]
However, since the resin-coated support is coated with a polyolefin resin layer on both sides of the base paper, the surface smoothness is generally too high, and the slipperiness cannot be obtained as it is, resulting in a problem in running performance. For this reason, conventionally, a method has been studied in which a matting agent (fine particles) or the like is blended when the toner image-receiving layer or the back layer is applied to make the surface appropriate roughness (for example, Patent Documents 1 to 3). reference).
[0004]
Patent Document 1 proposes an electrophotographic image receiving sheet comprising an image receiving layer containing fine particles of an ethylene / vinyl acetate copolymer on one side of a base sheet and a back layer containing an antistatic agent on the other side. ing.
Patent Document 2 proposes a color electrophotographic image receiving material in which the flow receiving temperature of the image receiving layer is not higher than the flow starting temperature of the toner, and the back layer contains two or more kinds of fine particles having an average particle diameter of 5 μm or more different. Yes.
In Patent Document 3, a toner image-receiving layer and a back layer are provided on a support provided with a thermoplastic resin layer on the front and back surfaces of a base paper, and the back layer includes a thermoplastic resin, porous fine particles, and a cationic material. An electrophotographic image receiving material has been proposed.
[0005]
However, when the toner image-receiving layer surface is roughened, there is a concern that the image quality such as glossiness is impaired. In addition, Patent Documents 1 to 3 all improve running performance and adhesion resistance by blending (organic and inorganic) fine particles (mat agent) in the back layer. In these cases, the matting agent is likely to fall off, and the surface is likely to feel rough. For this reason, although the method of increasing the application | coating thickness of a back layer is examined, while raising cost, there exists a problem that a crack tends to deteriorate.
[0006]
In the fine particle (mat agent) blending in Patent Documents 1 to 3, the shape, size and blending amount can be adjusted, but it is difficult to design an effective surface shape only under these conditions. . Furthermore, in the prior art, a specific surface shape (roughness) has not been studied, and it is difficult to improve all of prevention of powder falling, surface roughness, running performance, and adhesion resistance. is there.
[0007]
[Patent Document 1]
JP-A-6-332221
[Patent Document 2]
JP 2002-169321 A
[Patent Document 3]
JP 2002-182417 A
[0008]
[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, the present invention can provide a good image having good glossiness and rich in photographic sense, and improving all of prevention of powder falling, surface roughness, running performance, and adhesion resistance. An object of the present invention is to provide an electrophotographic image-receiving sheet support that can be produced, a method for producing the same, an electrophotographic image-receiving sheet, and an image forming method using the electrophotographic image-receiving sheet.
[0009]
[Means for Solving the Problems]
  Means for solving the problems are as follows. That is,
<1> In the support for an electrophotographic image-receiving sheet in which a polyolefin resin layer is provided on both sides of the base paper,The polyolefin resin layer provided on both sides of the base paper has a two-layer structure,The back surface of the support has a Beck smoothness of 10,000 seconds or more and a center line average roughness (Ra) of 0.5 μm or less on the surface (surface) on the side where the toner image-receiving layer is provided. The Beck smoothness on the surface (back surface) on which the film is provided is 1500 seconds or less, the center line average roughness (Ra) is 0.5 μm or more and 20 μm or less, and the local peak sum average distance (S) is 20 μm or more and 100 μm or less. A support for an electrophotographic image-receiving sheet.
<2> The Beck smoothness on the surface (surface) of the support on which the toner image-receiving layer is provided is 15000 seconds or more, and the centerline average roughness (Ra) is 0.4 μm or less. The Beck smoothness on the surface (back surface) on the side where the back layer is provided is 1300 seconds or less, the centerline average roughness (Ra) is 0.75 μm or more and 10 μm or less, and the local peak top average interval (S) is 30 μm or more and 75 μm. The support for an electrophotographic image receiving sheet according to <1>, wherein:
<3> Simultaneously or immediately after casting the molten polyolefin resin on the surface of the base paper, the surface of the polyolefin resin layer is pressed and cooled with a cooling roll having a fine rough surface (fine mat surface). <1> to <2> obtained by pressing and cooling with a cooling roll having a rough surface (mat surface) on the surface of the polyolefin resin layer simultaneously or immediately after casting the molten polyolefin resin on the back surface An electrophotographic image-receiving sheet support according to any one of the above.
<4>The method for producing a support for an electrophotographic image-receiving sheet according to any one of <1> to <3>,Immediately or immediately after casting the molten polyolefin resin on the surface of the base paper, the surface of the polyolefin resin layer is pressed and cooled with a cooling roll having a fine rough surface (fine mat surface) and melted on the back surface of the base paper. Production of a support for an electrophotographic image receiving sheet, wherein the polyolefin resin layer is pressed and cooled with a cooling roll having a rough surface (mat surface) on the surface of the polyolefin resin layer at the same time or immediately after casting the polyolefin resin. Is the method.
<5> The method for producing a support for an electrophotographic image-receiving sheet according to <4>, wherein the surface temperature of the cooling roll is 0 ° C to 50 ° C.
<6> The electrophotographic image-receiving sheet according to any one of <4> to <5>, wherein the cooling roll having a rough surface (mat surface) has a center line average roughness (Ra) of 0.7 μm or more and 40 μm or less. It is a manufacturing method of the support body for vehicles.
<7> An electrophotographic image-receiving sheet comprising a support and at least one toner image-receiving layer on one surface of the support, and at least one back layer on the other surface of the support. As the support, the electrophotographic image-receiving sheet support according to any one of <1> to <3> is used, and the Beck smoothness on the surface on the toner image-receiving layer side is 10,000 seconds or more, and the center The line average roughness (Ra) is 0.5 μm or less, the Beck smoothness on the back surface on the back layer side is 1500 seconds or less, and the center line average roughness (Ra) is 0.5 μm or more and 20 μm or less, The image receiving sheet for electrophotography is characterized in that the average distance (S) between local peaks is 20 μm or more and 100 μm or less.
<8> The Beck smoothness on the surface on the toner image-receiving layer side is 15000 seconds or more, the centerline average roughness (Ra) is 0.4 μm or less, and the Beck smoothness on the back surface on the back layer side is The electrophotographic image-receiving sheet according to <7>, wherein it is 1300 seconds or less, the centerline average roughness (Ra) is 0.75 μm or more and 10 μm or less, and the local summit average interval (S) is 30 μm or more and 75 μm or less. It is.
<9> A toner image-receiving layer is provided by applying a coating solution containing a water-dispersed resin on the surface of the electrophotographic image-receiving sheet support according to any one of <1> to <3>, and the support The electrophotographic image-receiving sheet according to any one of <7> to <8>, wherein a back layer is provided by applying a coating liquid containing a water-dispersed resin on the back surface of the body.
<10> The electrophotographic image-receiving sheet according to <9>, wherein the water-dispersed resin is a soap-free water-dispersible polymer.
<11> Any one of <7> to <10> above, using a cooling / peeling type belt fixing type smoothing processing machine having a heating / pressurizing unit, a cooling unit, and a cooling / peeling unit. An image forming comprising: heating and pressing at a temperature equal to or higher than a softening point of a thermoplastic resin in the toner image-receiving layer of the electrophotographic image-receiving sheet according to claim 1; cooling and then peeling from the belt member in the heating and pressing means. Is the method.
<12> The image forming method according to <11>, wherein a fluorocarbonsiloxane rubber layer having a uniform thickness is provided on a surface of the fixing belt.
<13> The above-mentioned <11>, comprising a silicone rubber layer having a uniform thickness on the surface of the fixing belt, and a fluorocarbonsiloxane rubber layer having a uniform thickness provided on the surface of the silicone rubber layer. The image forming method described in 1.
<14> The image forming method according to any one of <12> to <13>, wherein the fluorocarbon siloxane rubber has a perfluoroalkyl ether group and / or a perfluoroalkyl group in a main chain.
[0010]
The support for an electrophotographic image-receiving sheet of the present invention is a support for an electrophotographic image-receiving sheet in which a polyolefin resin layer is provided on both sides of a base paper, on the surface (surface) of the support on the side where the toner image-receiving layer is provided. The Beck smoothness is 10,000 seconds or more, the center line average roughness (Ra) is 0.5 μm or less, and the Beck smoothness on the surface (back surface) of the support on which the back layer is provided is 1500 seconds or less. And the center line average roughness (Ra) is 0.5 μm or more and 20 μm or less, and the local peak sum average distance (S) is 20 μm or more and 100 μm or less. Thereby, it is possible to produce an electrophotographic image-receiving sheet capable of improving all of prevention of powder falling, surface roughness, runnability and adhesion resistance.
[0011]
The electrophotographic image-receiving sheet of the present invention comprises a support, at least one toner image-receiving layer on one side of the support, and at least one back layer on the other side of the support. As the support, the support for an electrophotographic image-receiving sheet of the present invention is used, the Beck smoothness on the surface on the toner image-receiving layer side is 10,000 seconds or more, and the centerline average roughness (Ra) is 0. 0.5 μm or less, the Beck smoothness on the back surface on the back layer side is 1500 seconds or less, the centerline average roughness (Ra) is 0.5 μm or more and 20 μm or less, and the local summit average interval (S) is It is 20 μm or more and 100 μm or less. As a result, an electrophotographic image-receiving sheet can be obtained that can improve all of prevention of powder falling, surface roughness, runnability, and adhesion resistance without impairing the image quality such as glossiness.
[0012]
The image forming method of the present invention uses a cooling / peeling type belt fixing type smoothing processor having a heating / pressurizing unit, a cooling unit, and a cooling / peeling unit, and cools and peels the electrophotographic image-receiving sheet of the present invention. To process. As a result, even if an oil-less machine without fixing oil is used, stable paper feeding without offset to the fixing roller and fixing belt can be realized, and the glossiness is unprecedented. A rich image can be realized.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
(Support for electrophotographic image-receiving sheet)
The support for an electrophotographic image-receiving sheet of the present invention comprises a polyolefin resin layer on both sides of a base paper, and further has other layers as necessary.
[0014]
In the present invention, the Beck smoothness on the surface (surface) of the support on which the toner image-receiving layer is provided is 10000 seconds or more, preferably 15000 seconds or more, and the center line average roughness (Ra) is 0.5 μm. It is below, and 0.4 micrometer or less is preferable. When the Beck smoothness on the surface of the support is less than 10,000 seconds, the gloss of the toner image is impaired, and a silver salt photographic-like high image quality cannot be obtained. On the other hand, when the center line average roughness (Ra) on the surface of the support exceeds 0.5 μm, the gloss of the toner image is impaired, and a silver salt photographic-like high image quality cannot be obtained.
[0015]
In the present invention, after satisfying the surface roughness of the surface of the support, the Beck smoothness on the surface (back surface) of the support on which the back layer is provided is 1500 seconds or less, and 1300 seconds or less. The center line average roughness (Ra) is 0.5 μm or more and 20 μm or less, the local peak sum average distance (S) is 20 μm or more and 100 μm or less, and the center line average roughness (Ra) is 0.75 μm or more and 10 μm. In the following, the local peak sum average distance (S) is preferably 30 μm or more and 75 μm or less.
When the Beck smoothness on the back surface of the support exceeds 1500 seconds, the frictional resistance between the sheets increases, and the running property tends to deteriorate. In addition, when the center line average roughness (Ra) on the back surface of the support is less than 0.5 μm, the frictional resistance between the sheets increases, the running property tends to deteriorate, and the adhesion resistance tends to deteriorate. On the other hand, if the thickness exceeds 20 μm, there is a concern that the back surface feels rough. Moreover, if the local peak top average distance (S) on the back surface of the support is less than 20 μm, a rough feeling tends to appear. On the other hand, when it exceeds 100 μm, the frictional resistance between sheets increases, the running property deteriorates, and the adhesion resistance also tends to deteriorate.
[0016]
Here, the Beck smoothness can be measured using a Beck smoothness tester based on JIS P8119. Moreover, the said centerline average roughness (Ra) and local peak top average space | interval (S) are based on the definition of the surface roughness in JISB0601, and can be measured using a surface shape measuring machine, for example.
[0017]
The support for an electrophotographic image-receiving sheet of the present invention has a fine rough surface (fine mat surface) on the surface of the polyolefin resin layer at the same time or immediately after casting the molten polyolefin resin on the surface of the base paper. Simultaneously or immediately after casting the molten polyolefin resin on the back side of the base paper, press cooling with a cooling roll having a rough surface (matte surface) with respect to the surface of the polyolefin resin layer. It is obtained by. A detailed method for producing the electrophotographic image-receiving sheet support will be described later.
[0018]
-Base paper-
The base paper is not particularly limited and may be appropriately selected depending on the intended purpose. For example, high-quality paper, edited by the Japan Photography Society, “Basics of Photographic Engineering—Silver Salt Photography”, published by Corona Co., Ltd. ( (Showa 54) Papers described on pages (223) to (240) are preferable.
[0019]
The raw material of the base paper (including synthetic paper) is not particularly limited and can be appropriately selected from various materials. For example, natural pulp selected from softwood and hardwood, synthetic pulp made of plastic materials such as polyethylene and polypropylene Or a mixture of natural pulp and synthetic pulp.
[0020]
The pulp that can be used as the raw material of the base paper is hardwood bleached kraft pulp (LBKP) from the viewpoint of improving the surface smoothness, rigidity and dimensional stability (curling property) of the base paper to a balanced and sufficient level at the same time. Preferably, softwood bleached kraft pulp (NBKP), hardwood sulfite pulp (LBSP) and the like can also be used.
As the pulp fiber, it is appropriate to mainly use hardwood pulp having a short fiber length.
A beater or refiner can be used for beating the pulp. In the pulp slurry obtained after beating the pulp (hereinafter sometimes referred to as “pulp stock”), various additives such as a filler, a dry paper strength enhancer, a sizing agent, and wet paper are used as necessary. A force enhancer, a fixing agent, a pH adjuster, other agents, and the like can be added.
[0021]
Examples of the filler include calcium carbonate, clay, kaolin, white clay, talc, titanium oxide, diatomaceous earth, barium sulfate, aluminum hydroxide, and magnesium hydroxide.
Examples of the dry paper strength enhancer include cationized starch, cationized polyacrylamide, anionized polyacrylamide, amphoteric polyacrylamide, and carboxy-modified polyvinyl alcohol.
Examples of the sizing agent include compounds containing higher fatty acids such as fatty acid salts, rosin derivatives such as rosin and maleated rosin, paraffin wax, alkyl ketene dimer, alkenyl succinic anhydride (ASA), and epoxidized fatty acid amide. Can be mentioned.
[0022]
Examples of the wet paper strength enhancer include polyamine polyamide epichlorohydrin, melamine resin, urea resin, and epoxidized polyamide resin.
Examples of the fixing agent include polyvalent metal salts such as aluminum sulfate and aluminum chloride, and cationic polymers such as cationized starch.
Examples of the pH adjuster include caustic soda and sodium carbonate.
As said other chemical | medical agent, an antifoamer, dye, a slime control agent, a fluorescent whitening agent etc. are mentioned, for example.
Furthermore, a softening agent etc. can also be added as needed. Examples of the softening agent are described in New Handbook for Paper Processing (edited by Paper Medicine Time), pages 554 to 555 (issued in 1980).
[0023]
The treatment liquid used for the surface sizing treatment may contain, for example, a water-soluble polymer, a water-resistant substance, a pigment, a dye, a fluorescent brightening agent, and the like.
Examples of the water-soluble polymer include cationized starch, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, gelatin, casein, sodium polyacrylate, and styrene-maleic anhydride copolymer sodium salt. And sodium polystyrene sulfonate.
[0024]
Examples of the water resistant substance include latex emulsions such as styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, polyethylene, vinylidene chloride copolymer, and polyamide polyamine epichlorohydrin.
Examples of the pigment include calcium carbonate, clay, kaolin, talc, barium sulfate, and titanium oxide.
[0025]
The base paper as described above is a ratio (Ea / Eb) of the longitudinal Young's modulus (Ea) and the transverse Young's modulus (Eb) in terms of improving the rigidity and dimensional stability (curlability) of the electrophotographic image receiving paper. ) Is preferably in the range of 1.5 to 2.0. In the range where the Ea / Eb value is less than 1.5 or more than 2.0, the rigidity and curl property of the electrophotographic image-receiving paper are liable to be deteriorated, and the running property during transportation is hindered. Absent.
[0026]
The Oken type smoothness of the surface of the base paper on the toner image-receiving layer side is preferably 210 seconds or more, and more preferably 250 seconds or more. If the Oken type smoothness is less than 210 seconds, the image quality of the toner image becomes poor, which is not preferable. In addition, although an upper limit is not specifically limited, In practice, about 600 seconds are preferable and about 500 seconds are more preferable.
Here, the Oken-type smoothness is measured according to JAPAN TAPPI No. 5 Smoothness defined by the B method.
[0027]
In general, it is known that the “strain” of paper differs based on the difference in the mode of beating. After beating, the elastic force (rate) of the paper made after paper beating is an important indicator of the degree of “strain” of the paper. Can be used as an additional factor. In particular, the elastic modulus of paper is measured by measuring the speed of sound propagating through the paper, using the relationship between the dynamic elastic modulus and density, which indicates the physical properties of the viscoelastic material of the paper, and using an ultrasonic vibration element. Can be obtained from the following equation.
E = ρc²(1-n²)
[E: dynamic elastic modulus, ρ: density, c: speed of sound in paper, n: Poisson's ratio]
[0028]
In the case of normal paper, since n = about 0.2, even if it is calculated by the following formula, it can be calculated without much difference.
E = ρc²
That is, if the density and sound speed of paper can be measured, the elastic modulus can be easily obtained. In the above equation, when measuring the speed of sound, various known devices such as Sonic Tester SST-110 (manufactured by Nomura Corporation) can be used.
[0029]
The density of the base paper is 0.9 g / cm³Above, 0.95 g / cm³Or more, preferably 0.95 to 1.2 g / cm³Is more preferable.
There is no restriction | limiting in particular in the thickness of the said base paper, According to the objective, it can select suitably, Usually, 30-500 micrometers is preferable, 50-300 micrometers is more preferable, 100-250 micrometers is still more preferable. There is no restriction | limiting in particular in the basic weight of the said base paper, According to the objective, it can select suitably, For example, 50-250 g / m²Is preferable, 100-200 g / m²Is more preferable.
[0030]
-Polyolefin resin layer-
As the polyolefin resin layer, for example, a polyolefin resin such as a homopolymer of α-olefin such as polyethylene and polypropylene and a mixture thereof is used. These polyolefin resins are not particularly limited in molecular weight as long as extrusion coating is possible, and can be appropriately selected according to the purpose. Usually, polyolefin resins having a molecular weight in the range of 20,000 to 200,000 are used. Used.
[0031]
There is no restriction | limiting in particular as said polyethylene resin, According to the objective, it can select suitably, For example, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (L-LDPE), etc. Is mentioned.
For example, the melt index is 5 to 30 g / 10 min, preferably 10 to 20 g / 10 min, and the density is 0.945 g in that the cut surface when cut to a specified size with a cutter or the like in the cutting process is uniform and clean. / Cm³40 to 75 parts by mass of the above high-density polyethylene, a melt index of 1 to 15 g / 10 min, preferably 2 to 10 g / 10 min, and a density of 0.930 g / cm³It is preferable to use a polyethylene resin mixture obtained by mixing 25 to 60 parts by mass of the following low density polyethylene. These resins may be used alone or in combination of two or more.
[0032]
The mixing ratio (HDPE / LDPE) of the high-density polyethylene and the low-density polyethylene is preferably 40 to 75/60 to 25 in terms of mass ratio, and the mass ratio is 50 to 70/50 to 30. It is more preferable. In the support having a polyolefin resin layer coated with a polyethylene mixture in which the high-density polyethylene is 75 parts by mass or more and the low-density polyethylene is less than 25 parts by mass, sufficient cutting characteristics (uniform cutting) Surface) may not be obtained. In addition, in a support having a polyolefin resin layer coated with a polyethylene mixture in which high-density polyethylene is less than 40 parts by mass and low-density polyethylene is 60 parts by mass or more, sufficient cutting characteristics (uniform cut surface) However, it is not preferable because the surface is partially melted by the heating roll at the time of fixing, causing a deterioration in surface properties or a jamming failure due to poor running.
[0033]
When a polyolefin resin layer is provided on both sides of the base paper, it is preferable to coat a polyolefin resin layer made of a polyethylene mixture having the above composition on both sides. Further, the polyolefin resin layer may contain an antistatic agent such as a surfactant or a metal oxide in order to adjust the surface electric resistance, and further serves as both a polyolefin resin layer containing these and a conductive layer. It may be used as a layer.
[0034]
In the present invention, with respect to the polyolefin resin layer, from the viewpoint of improving the image quality, when the polyolefin resin layer is a single layer, the polyolefin resin layer is included in the polyolefin resin layer. In at least one layer, an inorganic pigment such as titanium dioxide, a bluing agent, a fluorescent brightening agent, an antioxidant and the like may be contained, and it is particularly preferable to contain titanium dioxide. Moreover, when this polyolefin resin layer is a multilayer, the tackifier resin, adhesive resin, etc. can also be contained in the lowest layer which contact | connects a base paper from a viewpoint of making adhesiveness with a base paper favorable. Further, if necessary, an antioxidant, a release agent, a hollow polymer and the like may be contained.
[0035]
When the titanium dioxide is contained in the polyolefin resin layer, the form of the titanium dioxide is not particularly limited, and may be anatase type or rutile type. The anatase type is preferable, and the rutile type is preferable when priority is given to sharpness. In consideration of both whiteness and sharpness, anatase type and rutile type may be blended and used. Further, two polyolefin resin layers containing titanium dioxide may be used, one layer containing anatase-type titanium dioxide, and the other layer containing rutile-type titanium dioxide.
[0036]
The average particle size of the titanium dioxide is preferably 0.1 to 0.4 μm, for example. When the average particle size is less than 0.1 μm, it is difficult to uniformly mix and disperse in the polyolefin resin layer. On the other hand, when the average particle size exceeds 0.4 μm, sufficient whiteness cannot be obtained and the surface of the polyolefin resin layer is not obtained. Protrusions appear on the screen, which may adversely affect image quality.
[0037]
The titanium dioxide preferably has a particle surface treated with a silane coupling agent, and the silane coupling agent preferably has an end modified with ethoxy or methoxy. The treatment amount of the silane coupling agent is preferably 0.05 to 2.5% by mass, more preferably 0.5 to 2.0% by mass with respect to titanium dioxide. When the treatment amount of the silane coupling agent is less than 0.05% by mass, the surface treatment effect by the silane coupling agent may not be sufficient, while when it exceeds 2.5% by mass, it is excessive with respect to titanium dioxide. It may be a process.
[0038]
In order to suppress the activity of the titanium dioxide pigment, the surface of the titanium dioxide is preferably subjected to a surface treatment with an inorganic surface treatment agent before the surface treatment of the silane coupling agent. Examples of the inorganic surface treatment agent include Al.₂O₃And SiO₂It is preferable that the treatment amount (calculated in the form of an anhydride) of the inorganic surface treatment agent is 0.01 to 1.8% by mass with respect to titanium dioxide. -1.0 mass% is more preferable.
If the surface of the titanium dioxide is not subjected to an inorganic surface treatment, the heat resistance of the titanium dioxide is low, and the titanium dioxide may turn yellow when used in an extrusion laminate at around 320 ° C. Further, since the activity of titanium dioxide is not suppressed, the titanium dioxide particles are aggregated and caught in a metal filter net equivalent to 20 to 400 mesh which is generally provided in the vicinity of the extrusion laminate outlet to prevent extrusion of foreign matter. May cause an increase in pressure.
On the other hand, when the treatment amount of the inorganic surface treatment agent is 1.8% by mass or more with respect to titanium dioxide, moisture tends to adhere to the surface of the inorganic surface treatment agent, and when used for extrusion lamination, the growth of the die lip stain is remarkably accelerated. There is a case.
[0039]
The titanium dioxide is kneaded such as a metal roll of higher fatty acid, higher fatty acid ethyl, higher fatty acid amide, higher fatty acid, polyolefin wax and the like as a dispersion aid, and a two-roll, three-roll, kneader, Banbury mixer, continuous kneading, etc. And kneaded into the resin. As the dispersion aid, metal stearate is preferable, and zinc stearate is more preferable. The resin thus kneaded with the titanium dioxide pigment is formed into a pellet shape and used as a master batch of the titanium dioxide pigment.
[0040]
The titanium dioxide concentration in the pellet is preferably about 30 to 75% by mass. The concentration of the dispersion aid in the pellet is preferably about 0.5 to 10% by mass. When the titanium dioxide concentration is less than 30% by mass, the bulk of the pellet increases. Conversely, when it exceeds 75% by mass, the dispersibility of the titanium dioxide is deteriorated and the pellet is liable to be cracked. Moreover, it is preferable to dry dry or vacuum dry the masterbatch containing titanium dioxide at 50-90 degreeC for 2 hours or more before use.
[0041]
As content of the said titanium dioxide in the said polyolefin resin layer, 5-50 mass% is preferable, and 8-45 mass% is more preferable. When the content is less than 5% by mass, the resolution may be inferior. On the other hand, when the content exceeds 50% by mass, die streaks may occur during production.
[0042]
Examples of the bluing agent include commonly known ultramarine blue, cobalt blue, cobalt oxide phosphate, quinacridone pigments, and the like, and mixtures thereof. The particle size of the bluing agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually preferably in the range of 0.3 to 10 μm. In addition, when using a blueing agent for the uppermost layer of a polyolefin resin layer, it is preferable to contain 0.2-0.4 mass%. Moreover, when using for the lower layer side, it is preferable to make it contain 0-0.15 mass%.
[0043]
As content in the said polyolefin resin layer of the said antioxidant, about 50-1,000 ppm is preferable with respect to resin which forms the said polyolefin resin layer. The masterbatch containing the titanium dioxide pigment and the like thus produced is appropriately diluted with the resin forming the polyolefin resin layer and used for extrusion lamination.
[0044]
The tackifier resin is appropriately selected from rosin derivative resins, terpene resins (for example, polymer β-pinene), coumarone / indene resins, petroleum hydrocarbon resins, and the like. These may be used alone or in combination of two or more.
[0045]
Examples of the petroleum hydrocarbon resins include aliphatic petroleum resins, aromatic petroleum resins, dicyclopentadiene petroleum resins, copolymer petroleum resins, hydrogenated petroleum resins, alicyclic petroleum resins, and the like. Is mentioned. As the aliphatic petroleum resin, those having 5 carbon atoms are particularly preferable. As the aromatic petroleum resin, those having 9 carbon atoms are particularly preferable.
[0046]
As a compounding quantity of the said tackifier resin, 0.5-60 mass% is preferable normally with respect to resin which comprises the said polyolefin resin layer, and 10-35 mass% is more preferable. If the blending amount of the tackifier resin is less than 0.5% by mass, adhesion failure may occur. On the other hand, if it exceeds 60% by mass, neck-in during production may easily occur.
[0047]
Examples of the adhesive resin include ionomer, ethylene vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, and metal salts thereof. As a compounding quantity of the said adhesive resin, 20-500 mass% is preferable with respect to resin which forms the said polyolefin resin layer, and 50-200 mass% is more preferable. The tackifier resin and the adhesive resin may be used in combination.
[0048]
(Method for producing support for electrophotographic image-receiving sheet)
The method for producing a support for an electrophotographic image-receiving sheet of the present invention comprises a fine rough surface (fine mat surface) on the surface of the polyolefin resin layer immediately or immediately after casting the molten polyolefin resin on the surface of the base paper. ) And a cooling roll having a rough surface (matte surface) on the surface of the polyolefin resin layer at the same time or immediately after casting the molten polyolefin resin on the back surface of the base paper. To do.
In addition, before coating the resin for forming the polyolefin resin layer on one or both surfaces of the base paper, the base paper is subjected to activation treatment such as corona discharge treatment, flame treatment, glow discharge treatment, or plasma treatment. It is preferable.
[0049]
Specifically, the polyolefin resin layer is melted by melting pellets containing the titanium dioxide and the like that are heated and melted, and if necessary diluted with a resin that forms the polyolefin resin layer. On the base paper on which the molten polyolefin resin has been run, either a normal laminating method, a sequential laminating method, or a laminating method using a single-layer or multi-layer extrusion die such as a foot block type, a multi-manifold type, a multi-slot type, or a laminator It is formed by coating by any method. The shape of the single-layer or multi-layer extrusion die is not particularly limited and may be appropriately selected depending on the intended purpose. In general, a T die, a coat hanger die, and the like are preferable.
In addition, generally 300 to 340 degreeC is preferable as the melt extrusion temperature of polyolefin resin for obtaining desired surface shape and obtaining favorable adhesiveness with the base paper surface.
[0050]
In the polyethylene mixture used for the polyolefin resin layer, the mixing method of the high-density polyethylene and the low-density polyethylene is not particularly limited and can be appropriately selected depending on the purpose. For example, using a kneader extruder, a heat kneading roll, a Banbury mixer, a kneader, etc., after adding a predetermined amount of high-density polyethylene and low-density polyethylene and further adding various additives as necessary, these are melt-mixed. A method of pulverizing or pelletizing the mixture, a method of directly feeding in a simply blended state using an extruder, and performing extrusion coating, etc. can be appropriately employed.
[0051]
The thickness of the polyolefin resin layer formed on the side (surface) of the support on which the toner image receiving layer is formed is preferably 10 to 60 μm. On the other hand, the thickness of the polyolefin resin layer formed on the side (back surface) where the back layer of the support is formed is preferably 10 to 50 μm.
[0052]
The uppermost surface of the polyolefin resin layer on the toner image-receiving layer side (surface) of the support is molded with a center line average roughness (Ra) of 0.5 μm or less. A center line average roughness (Ra) of 0.5 μm or more and 20 μm or less is formed on the polyolefin resin layer surface on the side (back surface) where the toner image receiving layer is not formed.
The molding is preferably performed using a cooling roll. The surface temperature of the cooling roll is preferably 0 ° C to 50 ° C, more preferably 0 ° C to 30 ° C. If the surface temperature of the cooling roll is too high, the polyolefin resin layer is difficult to peel off from the cooling roll, and surface shape defects due to poor peeling may occur. On the other hand, if the surface temperature of the cooling roll is too low, the transfer of the surface of the cooling roll becomes insufficient and a desired surface shape cannot be obtained, and a water droplet failure may occur due to condensation on the surface of the cooling roll.
In addition, when the surface of the polyolefin resin layer is roughened by transferring the surface of the cooling roll, a roughness equivalent to the fine rough surface (fine mat surface) or the rough surface (mat surface) of the cooling roll is always formed. In consideration of the fact that the unevenness is slightly relaxed, (1) the center line average roughness (Ra) of the surface of the polyolefin resin layer on the toner image receiving layer side (surface) of the support is 0.5 μm or less. In this case, the center line average roughness (Ra) of the fine rough surface (fine mat surface) of the cooling roll is preferably 1.0 μm or less (preferably 0.7 μm or less). (2) When the center line average roughness (Ra) of the polyolefin resin layer surface on the side where the toner image-receiving layer is not formed (back surface) in the support is 0.5 μm or more and 20 μm or less, the cooling roll roughness The center line average roughness (Ra) of the surface (mat surface) is preferably 0.7 μm or more and 40 μm or less (preferably 1.0 μm or more and 25 μm or less).
[0053]
There is no restriction | limiting in particular as a manufacturing method of the cooling roll which has the said fine rough surface (fine mat | matte surface) thru | or rough surface (matte surface), According to the objective, it can select suitably, For example, a sandblasting method, a liquid homing method , Electroporation, and the like. Among these, sandblasting is preferable.
Specifically, with or without copper plating on the iron core roll, fine irregularities are formed on the copper plating surface or the iron core roll surface by any of the sandblasting method, liquid homing method, and electroporation method. Form and roughen. If the required rough surface is obtained, apply plating. There is no restriction | limiting in particular as this plating, According to the objective, it can select suitably, For example, chromium plating is preferable from operativity etc., and hard chromium plating is especially preferable. In addition, as for the thickness of the said plating layer, 10 micrometers-50 micrometers are preferable.
[0054]
Next, the surface of the polyolefin resin layer after molding can be subjected to activation treatment such as corona discharge treatment or flame treatment. After the activation treatment, the surface as described in JP-A-61-84443 is used. Pull processing can also be performed.
[0055]
(Electrophotographic image-receiving sheet)
The electrophotographic image-receiving sheet of the present invention comprises the support for an electrophotographic image-receiving sheet, at least one toner image-receiving layer provided on one side of the support, and at least one back on the other side of the support. A layer is provided. Further, other layers appropriately selected as necessary, for example, surface protective layer, intermediate layer, undercoat layer, cushion layer, reflective layer, tint adjusting layer, storage stability improving layer, adhesion preventing layer, anti-curl layer, smoothing It has a layer. Each of these layers may have a single layer structure or a laminated structure.
[0056]
In the present invention, the Beck smoothness on the surface of the toner image-receiving layer side is 10,000 seconds or more, preferably 15000 seconds or more, and the center line average roughness (Ra) is 0.5 μm or less, 0.4 μm or less. Is preferred.
When the Beck smoothness on the surface of the toner image-receiving layer side is less than 10,000 seconds, the gloss of the toner image is impaired, and a silver salt photographic-like high image quality cannot be obtained. On the other hand, when the center line average roughness (Ra) on the surface of the support exceeds 0.5 μm, the gloss of the toner image is impaired, and a silver salt photographic-like high image quality cannot be obtained.
[0057]
In the present invention, after satisfying the surface roughness of the surface on the toner image-receiving layer side, the Beck smoothness on the back surface on the back layer side is 1500 seconds or less, preferably 1300 seconds or less, and the center line The average roughness (Ra) is 0.5 μm or more and 20 μm or less, and the local peak top average distance (S) is 20 μm or more and 100 μm or less, the center line average roughness (Ra) is 0.75 μm or more and 10 μm or less, and the local peak top average The interval (S) is preferably 30 μm or more and 75 μm or less.
When the Beck smoothness on the back surface on the back layer side exceeds 1500 seconds, the frictional resistance between the sheets increases, and the running property tends to deteriorate. In addition, when the center line average roughness (Ra) on the back surface on the back layer side is less than 0.5 μm, the frictional resistance between the sheets increases, the running property tends to deteriorate, and the adhesion resistance tends to deteriorate. On the other hand, if the thickness exceeds 20 μm, there is a concern that the back surface feels rough. Moreover, if the local peak sum average distance (S) on the back surface on the back layer side is less than 20 μm, a rough feeling tends to appear. On the other hand, when it exceeds 100 μm, the frictional resistance between sheets increases, the running property deteriorates, and the adhesion resistance also tends to deteriorate.
[0058]
Here, the Beck smoothness can be measured using a Beck smoothness tester based on JIS P8119. Moreover, the said centerline average roughness (Ra) and local peak top average space | interval (S) are based on the definition of the surface roughness in JISB0601, and can be measured using a surface shape measuring machine, for example.
[0059]
In the present invention, in order to achieve the surface roughness of the toner image receiving layer and the back layer (especially, when the toner image receiving layer and the back layer have a multi-layer structure, the surface roughness), the electrophotography of the present invention is used. A coating liquid containing a water-dispersed resin is applied to the front and back surfaces of the image-receiving sheet support for forming a toner image-receiving layer and a back layer.
There is no restriction | limiting in particular as said water-dispersed resin, Although it can select suitably according to the objective, It is preferable to contain a soap free type water-dispersible polymer.
[0060]
[Toner image receiving layer]
The toner image-receiving layer is formed in at least one layer, and the outermost surface layer thereof contains a soap-free water-dispersible polymer, and further contains other components as necessary.
[0061]
The soap-free water-dispersible polymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an aromatic polyester resin or an acrylic copolymer resin is preferable.
[0062]
-Aromatic polyester resin-
As the aromatic polyester resin, it is preferable to use a self-dispersing water-based polyester resin emulsion that satisfies the following characteristics (1) to (4). Since this is a self-dispersion type that does not use a surfactant, it has low hygroscopicity even in a high humidity atmosphere, and there is little decrease in the softening point due to moisture, and it is possible to suppress the occurrence of offset during fixing and the failure of adhesion between sheets during storage. In addition, it is environmentally friendly and workable because it is aqueous. In addition, since a polyester resin with a high cohesive energy and a molecular structure is used, it has a sufficient hardness in the storage environment, but it becomes a low elasticity (low viscosity) molten state in the electrophotographic fixing process, and the toner receives an image. Sufficient image quality can be achieved by embedding in the layer.
(1) The glass transition temperature (Tg) is preferably 20 to 80 ° C, more preferably 40 to 70 ° C.
(2) The number average molecular weight (Mn) is preferably 5,000 to 10,000, and more preferably 5,000 to 7,000.
(3) The molecular weight distribution (weight average molecular weight / number average molecular weight) is preferably ≦ 4, more preferably Mw / Mn ≦ 3.
(4) The volume average particle diameter is preferably 20 to 200 nmφ, more preferably 40 to 150 mmφ.
[0063]
The method for producing the self-dispersing water-based polyester resin emulsion includes an aromatic polyester resin having a glass transition temperature (Tg) of 20 to 80 ° C. and hydrophilicity as described in JP-A No. 2002-173582. Organic solvent, neutralizing agent for ionizing carboxyl group of polyester resin (unnecessary if ionized already), water, all these raw materials are included, at 40 ° C to 100 ° C for several minutes to several A method of stirring with heating for a time can be mentioned. At this time, when the heating temperature is less than 40 ° C., the viscosity increase of the self-dispersing water-based polyester resin emulsion is increased, which is not preferable in terms of work.
[0064]
-Acrylic copolymer resin-
The acrylic copolymer resin is obtained by emulsion polymerization of two or more monomers selected from the following (1) to (4) in an aqueous solvent in the presence of a reactive emulsifier, and the following (5) and ( What has the characteristic of 6) is preferable.
(1) Aromatic ethylenically unsaturated monomer
(2) An ethylenically unsaturated monomer having an epoxy group
(3) Ethylenically unsaturated carboxylic acid monomer
(4) Other ethylenically unsaturated monomers copolymerizable with any of the monomers (1) to (3)
(5) The glass transition temperature (Tg) is preferably 20 to 80 ° C, more preferably 40 to 70 ° C.
(6) The volume average particle diameter is preferably 20 to 200 nmφ, more preferably 40 to 150 mmφ.
[0065]
The aromatic ethylenically unsaturated monomer (hereinafter sometimes referred to as “monomer A”) is a monomer having an aromatic ring and a radically polymerizable vinyl group in one molecule. Examples thereof include aromatic vinyl compounds such as styrene, α-methylstyrene, vinyl toluene, and ethyl vinyl benzene, and (meth) acrylates having an aromatic ring such as benzyl (meth) acrylate and benzoyl (meth) acrylate. It is done. These may be used alone or in combination of two or more.
The amount of the monomer A used in the acrylic copolymer resin is preferably 40 to 99 parts by mass, more preferably 45 to 80 parts by mass, and still more preferably 50 to 70 parts by mass in all the monomers used.
By making the usage-amount of the said monomer A into 40-99 mass parts, both printability and solvent resistance become favorable.
[0066]
The ethylenically unsaturated monomer having an epoxy group (hereinafter sometimes referred to as “monomer B”) is a monomer having an epoxy group and a radically polymerizable vinyl group in one molecule. Examples thereof include epoxy derivatives such as glycidyl (meth) acrylate, metaglycidyl (meth) acrylate, allyl glycidyl ether, epoxycyclohexyl (meth) acrylate, and epoxidized butadiene. These may be used alone or in combination of two or more.
The amount of the monomer B used in the acrylic copolymer resin is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, and still more preferably 2 to 7 parts by mass in all monomers used. .
By making the usage-amount of the said monomer B into 0.5-10 mass parts, both solvent resistance and printability will become favorable.
[0067]
The ethylenically unsaturated carboxylic acid monomer (hereinafter sometimes referred to as “monomer C”) is a monomer having a carboxyl group and a vinyl group capable of radical polymerization in one molecule.
Specific examples of the monomer C or those that change to the monomer C when emulsion polymerization is performed using an aqueous solvent include (a) to (e) shown below. These may be used alone or in combination of two or more.
(A) Monocarboxylic acids such as acrylic acid, (meth) acrylic acid and crotonic acid
(B) Dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid
(C) Half esters such as methyl maleate, methyl itaconate, β-methacryloxyethyl acyl hexahydrophthalate
(D) Anhydrides of unsaturated carboxylic acids of (a) and (b) above. For example, acrylic acid anhydride, maleic acid anhydride, and the like change to carboxylic acid when emulsion polymerization is performed in an aqueous solvent, and thus can be used as monomers for emulsion polymerization.
(E) Potassium salts, sodium salts and ammonium salts of (a) to (d)
The amount of the monomer C used in the acrylic copolymer resin is preferably 0.5 to 10 parts by mass, more preferably 0.7 to 7 parts by mass, and 1 to 5 parts by mass in all monomers used. Further preferred.
By making the usage-amount of the said monomer C into 0.5-10 mass parts, solvent resistance, water resistance, and printability will become favorable.
[0068]
The other ethylenically unsaturated monomer (hereinafter sometimes referred to as “monomer D”) may be any monomer that can be copolymerized with the monomer A to the monomer C. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i- (meth) acrylate Butyl, n-amyl (meth) acrylate, i-amyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid Octyl, i-nonyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, hydroxymethyl (meth) acrylate (Meth) acrylic acid alkyl esters such as hydroxyethyl (meth) acrylate; aminoalkyl esters of ethylenically unsaturated carboxylic acids such as aminoethyl acrylate, dimethylaminoethyl acrylate and butylaminoethyl acrylate; diacetone (meth) acrylamide, etc. Compounds having a carbonyl group in the molecule; (meth) acrylates having various functional groups such as N-methylol (meth) acrylamide, γ- (meth) acryloxypropyltrimethoxysilane; ethylene glycol di (meth) acrylate, tri Multifunctional (meth) acrylates such as methylolpropane tri (meth) acrylate; 1,2,2,6,6-pentamethyl-4-piperyl methacrylate, 2,2,6,6-tetramethyl-4-pipe UV-absorbing (meth) acrylates such as lysyl methacrylate having a light stabilizing function; 2-hydroxy-4-methacryloxybenzophenone, 2- [2′-hydroxy-5methacryloloxyethyl] phenyl] benzotriazole Functional (meth) acrylate compounds; aliphatic conjugated dienes such as 1,3-butadiene, isoprene and 2-chloro-1,3-butadiene; vinyl carboxylic acid esters such as vinyl acetate and vinyl propionate; ethylenically unsaturated Dicarboxylic acid anhydrides, monoalkyl esters, monoamides; vinyl cyanide compounds such as (meth) acrylonitrile and α-chloroacrylonitrile, acrolein, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc. Rukoto can. These may be used alone or in combination of two or more.
The usage amount of the monomer D occupies the remaining portion excluding the monomer A to monomer C among all the monomers used.
[0069]
The gel fraction of the polymer particles contained in the acrylic copolymer resin is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more. By setting the gel fraction to 70% or more, the solvent resistance is improved.
As described above, the gel fraction refers to the proportion of a polymer particle that occupies a portion that forms a high-molecular-weight three-dimensional network structure. Usually, the polymer particle is insoluble in an organic solvent such as toluene. Measured.
For the gel fraction, the monomer A to the monomer D are used within the scope of the present invention, the type and amount of the radical polymerization initiator, the polymerization temperature, and the type and amount of the chain transfer agent used as necessary. Can be adjusted by.
[0070]
-Manufacturing method of aqueous dispersion-
The aqueous dispersion is obtained by adding a polymerization initiator to a mixture of two or more monomers in the presence of a reactive emulsifier described later in an aqueous solvent and copolymerizing the mixture. In such emulsion polymerization, first, a monomer is subjected to addition polymerization by radically decomposing a polymerization initiator in the presence of heat or a reducing substance to cause a polymerization initiation reaction.
[0071]
-Polymerization initiator-
As the polymerization initiator used in the production of the aqueous dispersion, for example, an oxidizing agent composed of organic hydroperoxides such as cumene hydroperoxide, diisopropyl benzene hydroperoxide, paramentane hydroperoxide and sugar-containing iron pyrophosphate prescription, Redox initiators in combination with reducing agents such as sulfoxylate prescription, sugar-containing iron pyrophosphate prescription / melboxylate prescription; persulfates such as potassium persulfate and ammonium persulfate; azobisisobutyro Azo compounds such as nitrile, dimethyl-2,2′-azobisisobutyrate, 2-carbamoylazaisobutyronitrile; benzoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, etc. List organic peroxides It can be, and preferably the initiator of the persulfate and the redox system.
0.05-5 mass parts is preferable per 100 mass parts of all monomers, and, as for the usage-amount of the said polymerization initiator, 0.1-2 mass parts is more preferable. When emulsion polymerization is performed using these polymerization initiators, the polymerization initiator is added all at once in the reaction system, or a part of the polymerization initiator is added batchwise, continuously, or a combination of both. The method of adding can be used.
[0072]
-Reactive emulsifier-
The soap-free water-dispersible polymer is obtained by radical polymerization of two or more monomers in the presence of a reactive emulsifier.
Here, the reactive emulsifier refers to an emulsifier having an emulsifying ability to the extent that emulsion polymerization is possible and capable of radical polymerization.
In the present invention, the amount of emulsifier used can be reduced by carrying out emulsion polymerization using a reactive emulsifier, and in particular, the amount of free emulsifier in an aqueous medium can be reduced. An excellent copolymer emulsion can be obtained.
Examples of the reactive emulsifier include an emulsifier having an ethylenically unsaturated group as a radical reactive group, a polyoxyethylene group as a hydrophilic group, a sulfone group, a sulfuric acid group, and an alkyl group as a hydrophobic group in one molecule.
Examples of such reactive emulsifiers include “Latemul S-180A” (manufactured by Kao Corporation); “Eleminol JS-2” (manufactured by Sanyo Chemical Co., Ltd.); “Aqualon HS-10”, “Aquaron BC” -10 ”(Daiichi Kogyo Seiyaku Co., Ltd.); Anionic reactive emulsifiers such as“ Adekaria Soap SE-10N ”(Asahi Denka Kogyo Co., Ltd.),“ Aqualon RS-20 ”(Daiichi Kogyo Seiyaku) Non-ionic reactive emulsifiers such as “Adekaria Soap NE-20” (Asahi Denka Kogyo Co., Ltd.). These may be used alone or in combination of two or more.
[0073]
Although the usage-amount of the reactive emulsifier in this invention is based on the particle diameter mentioned later, 0.5-5 mass parts is preferable with respect to 100 mass parts of all monomers, and 0.5-3 mass parts is more preferable.
By making the usage-amount of the said reactive emulsifier 0.5-5 mass parts, stability at the time of a polymerization reaction can be hold | maintained, emulsification is enough, and foaming is also suitable.
The reactive emulsifier is preferably added to the polymerization system in a batch, batchwise addition, continuous addition, or a combination of both.
[0074]
In the polymerization of the aqueous dispersion, a chain transfer agent, an electrolyte, a chelating agent, a pH adjusting agent, and the like may be used in combination with the above-described emulsifier and polymerization initiator as necessary.
The amount of the chain transfer agent used is preferably about 0 to 5 parts by mass per 100 parts by mass of all monomers.
[0075]
Examples of the pH adjuster include ammonia water, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, disodium hydrogen phosphate and the like. The amount of the pH adjuster used is preferably 0 to 2 parts by mass per 100 parts by mass of all monomers.
[0076]
As an example of the polymerization method, 100 parts by mass of a monomer mixture, 100 to 500 parts by mass of water, 0.05 to 5 parts by mass of a polymerization initiator, 0.01 to 5 parts by mass of a reactive emulsifier, and chain transfer An aqueous reaction system composed of a predetermined amount of an agent, an electrolyte, and a pH adjuster is allowed to react for 0.1 to 10 hours under a preferable temperature condition of 5 to 100 ° C. (particularly 50 to 90 ° C.).
The polymerization method at that time includes a method of adding all monomers at once, a method of adding at least a part of monomers in a divided or continuous manner, and a method of dividing or continuously at least a part of the pre-emulsion of monomers. Can be used, or these methods can be combined stepwise, especially when using monomers with low water solubility. ・ Use a high-pressure homogenizer or ultrasonic disperser. By pre-emulsion by forcibly emulsifying at least part of the monomer mixture, water, reactive emulsifier, etc. in advance, and then adding the remaining monomers all at once, or by dividing or continuously adding It can also be polymerized.
[0077]
-Other additives-
Depending on the purpose, the above aqueous dispersion includes a light stabilizer, an ultraviolet absorber, an organic solvent, a crosslinking agent, a water-soluble polymer (for example, a water-soluble polyester resin, a water-soluble epoxy resin, a water-soluble acrylic resin, Polyvinyl alcohol, starch), antifoaming agents, thickeners, heat stabilizers, leveling agents, lubricants, antistatic agents, colorants, matting agents, pigments, antifungal agents and the like may be contained. .
[0078]
The light stabilizer / ultraviolet absorber added and contained in the aqueous dispersion is not particularly limited, and is known as a light stabilizer / ultraviolet absorber for paints, synthetic rubbers, synthetic resins, and synthetic fibers. Can be used. Specific examples include light stabilizers such as organic nickel and hindered amines; inorganic ultraviolet absorbers such as titanium oxide, zinc oxide, and cerium oxide; organic ultraviolet absorbers such as benzophenone and benzotriazole. Can do. Of these, hindered amine light stabilizers such as bis (1,2,2,6,6-pentamethyl-4-biperidyl) sebacate; cerium oxide and hindered amine ultraviolet absorbers are preferred. The addition amount of the light stabilizer / ultraviolet absorber is usually preferably 0.01 to 10 parts by mass and more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the specific polymer (solid content). . By including a light stabilizer / ultraviolet absorber, good weather resistance can be exhibited in the coating film formed by the aqueous dispersion of the present invention.
[0079]
Examples of the organic solvent added to the aqueous dispersion include alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, and hexyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, and hexyl. Examples thereof include cellosolve methyl carbitol, ethyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, and tributoxymethyl phosphate.
The addition amount of the organic solvent is usually preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the solid content of the aqueous dispersion. By including the organic solvent, the wettability and film forming property of the obtained aqueous dispersion can be improved.
[0080]
The crosslinking agent added to and contained in the aqueous dispersion is not particularly limited and can be appropriately selected according to the purpose. For example, the crosslinking agent made of a thermosetting resin such as an amino resin, a phenol resin, or an epoxy resin. Well-known crosslinking agents such as organic crosslinking agents such as hydrazide compounds, isocyanate compounds, blocked isocyanate compounds and aziridine compounds, and inorganic crosslinking agents such as metal compounds can be used.
[0081]
According to the cross-linking agent, the cross-linking (curing) reaction can proceed under a temperature condition of 0 to 280 ° C. And among the said crosslinking agents, what consists of an amino resin, a phenol resin, and a blocked isocyanate compound can advance a crosslinking reaction on the temperature conditions of 100 degrees C or less, and is preferable. By containing a cross-linking agent, it is possible to impart further excellent solvent resistance and water resistance to the coating film formed from the aqueous dispersion.
[0082]
By using the monomer A among all the monomers, the printability can be improved and the glass transition temperature (Tg) can be increased. Further, by crosslinking with the monomer B, the solvent resistance and water resistance can be increased. , Alkali resistance and acid resistance can be improved. Therefore, according to the aqueous dispersion of the present invention, a coating film excellent in solvent resistance, water resistance, printability, acid resistance and alkali resistance can be formed.
[0083]
The toner image-receiving layer contains a polymeric antistatic agent in addition to the soap-free water-dispersible polymer (for example, aromatic polyester resin and acrylic copolymer resin).
[0084]
-Polymeric antistatic agent-
Examples of the polymer antistatic agent include a water-soluble polymer compound having a carboxyl group or a sulfone group, and a metal salt thereof, and at least any of a carboxyl group, a sulfone group, a phosphate group, an amine group, an amide group, and a hydroxyl group. What is chosen from the hydrophilic organic polymer aqueous dispersion which has these is preferable.
It is preferable that the hydrophilic organic polymer aqueous dispersion is an emulsion of a block copolymer having a hydrophilic block and a hydrophobic block.
[0085]
Examples of the water-soluble polymer compound having a carboxyl group include ethylenically unsaturated monomers having 4 or more carbon atoms, for example, unsaturated copolymerizable monomers such as α-olefins having 4 or more carbon atoms, alkyl vinyl ethers, or styrene. And a copolymer of maleic anhydride are preferred, and their salts are obtained by hydrolyzing them with an alkali such as sodium hydroxide or potassium hydroxide.
[0086]
The molecular weight of the copolymer of an unsaturated copolymerizable monomer having 4 or more carbon atoms and maleic anhydride is preferably 2000 to 150,000. Specific examples thereof include a solution obtained by hydrolyzing a copolymer of isobutylene, 1-pentene, butyl vinyl ether, or styrene and maleic anhydride together with an alkali such as sodium hydroxide or potassium hydroxide. The reaction product etc. which are 5.0-9.0 are mentioned. In addition to these, a copolymer of styrene and itaconic acid or crotonic acid, a copolymer of methyl acrylate and citraconic acid, or a metal salt thereof can be used.
[0087]
The water-soluble polymer compound having a sulfone group preferably has a molecular weight of 5,000 to 1,000,000. For example, polystyrene sulfonic acid, polyvinyl benzyl sulfonic acid, etc., or salts thereof such as sodium and potassium can be mentioned. Examples of the metal salt include polyacrylic acid soda and polystyrene sulfonate soda, and examples of the hydrophilic organic polymer aqueous dispersion include carboxyl-modified polyethylene or a salt thereof.
[0088]
-Hydrophilic organic polymer aqueous dispersion-
The hydrophilic organic polymer aqueous dispersion having a carboxyl group, a sulfone group, a phosphoric acid group, an amine group, an amide group or a hydroxyl group is an emulsion of a block copolymer having a hydrophilic block and a hydrophobic block. Is preferred.
In the block copolymer having the hydrophilic block and the hydrophobic block, examples of the hydrophobic block include a polymer or a copolymer unit mainly composed of a hydrocarbon monomer. As a polymer or copolymer unit mainly composed of the hydrocarbon monomer, a (co) polymer mainly composed of a diene monomer, an olefin based unit such as an aromatic vinyl compound or olefin. Preferred are (co) polymers mainly composed of monomers or (co) polymer units obtained by hydrogenation of these.
[0089]
In the block copolymer, examples of the hydrophilic block include those obtained by adding a hydrophilic group to the hydrophobic polymer unit. Examples of such hydrophilic groups include sulfone groups, carboxylic acid groups (carboxyl groups), phosphoric acid groups, amine groups, amide groups, hydroxyl groups, alkyl ester groups, acid anhydride groups, and the like. Among these, a sulfone group, a carboxylic acid group (carboxyl group), a phosphoric acid group, an amine group, an amide group, and a hydroxyl group are preferable, a sulfone group and a carboxylic acid group (carboxyl group) are more preferable, and a sulfone group is particularly preferable. It is. For example, (co) polymers mainly composed of diene monomers, (co) polymers mainly composed of olefin monomers such as aromatic vinyl compounds and olefins, or (co) polymers obtained by hydrogenating these And a unit of a (co) polymer having a hydrocarbon monomer as a main component, such as a unit of the above, and a hydrophilic group such as a sulfone group.
[0090]
The diene monomer used in the (co) polymer unit mainly composed of the diene monomer is preferably a diene compound having 4 to 12 carbon atoms, more preferably 4 to 8 carbon atoms, Particularly preferred are diene compounds having 4 to 6 carbon atoms.
[0091]
The (co) polymer unit mainly composed of olefin monomers is a (co) polymer unit mainly composed of olefin monomers such as aromatic vinyl compounds and olefins. Examples of the aromatic vinyl compound include styrene, α-methyl styrene, o-methyl styrene, p-til styrene, m-methyl styrene, vinyl naphthalene, and the like. Examples of the olefin include ethylene and propylene. These monomers may be used alone or in combination of two or more. Of these, aromatic vinyl compounds are preferable, and styrene is particularly preferable.
[0092]
Further, the (co) polymer mainly composed of the diene monomer, the (co) polymer mainly composed of an olefin monomer such as an aromatic vinyl compound or olefin, or a hydrogenated (co) polymer. In addition to the above monomers, other monomers can be used in combination in the unit of coalescence.
[0093]
The (co) polymer unit mainly composed of the diene monomer may be copolymerized with the above aromatic vinyl compound or olefin as another monomer. In addition, the (co) polymer unit mainly composed of an aromatic vinyl compound may be copolymerized with the diene monomer or olefin in an inferior amount. In addition, the (co) polymer unit mainly composed of olefins may be copolymerized with the above-mentioned diene monomer or aromatic vinyl compound as another monomer. When these other monomers are used in combination, the amount of the monomer used is usually preferably 60% by mass or less, more preferably 50% by mass or less, and more preferably 30% by mass in each (co) polymer unit. The following is more preferable, and 20% by mass or less is particularly preferable.
[0094]
Production of the block copolymer (base polymer), that is, a (co) polymer unit mainly comprising a diene monomer and an olefin monomer such as an aromatic vinyl compound or olefin (copolymer). ) A block copolymer containing a polymer unit can be produced by copolymerizing each monomer using an initiator and optionally using a solvent. As the polymerization method, anionic polymerization is particularly preferably used from the viewpoint of obtaining a block copolymer.
[0095]
Further, the block copolymer can be used by hydrogenating (hydrogenating) part or all of the residual double bond based on the diene monomer. In this case, a known hydrogenation catalyst can be used, and examples thereof include a catalyst and a method described in JP-A-5-222115. After the block copolymer as the base polymer is hydrogenated, a hydrophilic group can be introduced by a method described later. However, after the hydrophilic group is introduced into the copolymer, hydrogenation may be performed.
[0096]
The base polymer used in the present invention is preferably a block copolymer containing a polymer unit A containing a diene monomer and a polymer unit B containing an olefin monomer. As a preferable structure of the block copolymer, AB type, A (BA) n type, B (AB) n type, or (AB) n type (where n is preferably 1 to 5, more preferably 1 to 5). 3, more preferably 1 to 2, particularly preferably 1).
[0097]
Among these, AB type, ABA type, and BAB type block copolymers are preferable. Specifically, preferable base polymers include, for example, isoprene-styrene block copolymer, styrene-isoprene-styrene terpolymer block copolymer, isoprene-styrene-isoprene ternary block copolymer, butadiene-styrene block copolymer. Examples thereof include a polymer, a styrene-butadiene-styrene ternary block copolymer, a butadiene-styrene-butadiene ternary block copolymer, and hydrogenated products of these block copolymers. Further, the aromatic monomer or other monomer may be partially copolymerized in the block chain of the diene monomer unit, and the diene monomer or other monomer may be co-polymerized in the block chain of the aromatic monomer unit. It may be partially copolymerized.
[0098]
The polystyrene-equivalent weight average molecular weight (hereinafter referred to as “Mw”) of these base polymers or hydrogenated products thereof is preferably 1,000 to 1,000,000, more preferably 2,000 to 500,000, and 5,000. ~ 200,000 is more preferred. If the Mw is less than 1,000, the antistatic property of the polymer emulsion having antistatic properties may decrease over time, while if it exceeds 1,000,000, the polar group may be introduced. Problems such as gelation may occur.
[0099]
In the block copolymer, the ratio A / B of the polymer unit A containing a diene monomer and the polymer unit B containing an olefin monomer is, in the case of a block copolymer not hydrogenated, 1-80 / 99-20 are preferable, 2-70 / 98-30 are more preferable, and 5-50 / 95-50 are still more preferable. Moreover, in the case of the hydrogenated block copolymer, 20-99 / 80-1 are preferable, 30-98 / 70-2 are more preferable, 50-95 / 50-5 are still more preferable.
[0100]
The degree of polymerization of each of the polymer units A and B is preferably 10 or more, B is preferably 20 or more, A is 50 or more, and B is 100 or more, more preferably in the case of a block copolymer that is not hydrogenated. Is more preferably 100 or more and B is 200 or more. In the case of a hydrogenated block copolymer, A is preferably 20 or more, B is preferably 10 or more, A is 100 or more, B is 50 or more, A is 200 or more, and B is 100 or more. .
[0101]
A block copolymer having a hydrophilic group can be obtained by copolymerizing a monomer (monomer) containing a hydrophilic group to the base polymer composed of the block copolymer or by adding a hydrophilic group to the base polymer. Can be manufactured. As a method for adding a hydrophilic group by a method such as addition, a known method can be used. For example, when a sulfone group is introduced, it is produced by sulfonation by a method described in, for example, the Japan Society for the Science, New Experiment Course (Vol. 14, III, page 1773), JP-A-2-227403, etc. Can do.
[0102]
The content of the hydrophilic group in the block copolymer into which the hydrophilic group is introduced as described above is usually preferably such that the number of monomer units containing a hydrophilic group is 50 (mol)% or more of the constituent monomer units in the block, 70 % Or more is more preferable. By setting it to 50% or more, sufficient antistatic properties can be obtained. The hydrophobic block may contain a hydrophilic group, but the number of monomer units containing a hydrophilic group is preferably 10 (mol)% or less of the constituent monomer units in the hydrophobic block, preferably 5% or less. More preferred. Moreover, the polar group content in the block copolymer into which a hydrophilic group has been introduced is preferably 0.1 to 5 mmol / g, more preferably 0.2 to 3 mmol / g, and further 0.3 to 2.5 mmol / g. 0.5 to 2 mmol / g is particularly preferable. If it is less than 0.1 mmol / g, the antistatic property is hardly exhibited, and if it is too much, water resistance may be a problem.
[0103]
In the present invention, the hydrophilic group-containing block copolymer is usually used in a state of being emulsified and dispersed in a medium such as water. The method for emulsifying and dispersing is not particularly limited, but preferably, the organic solvent solution of the hydrophilic group-containing block copolymer is mixed with water and emulsified, and then the organic solvent is removed while leaving the water. be able to.
[0104]
The particle size of the hydrophilic group-containing block copolymer emulsion thus obtained is usually preferably 1 to 500 nm, more preferably 1 to 300 nm, and still more preferably 1 to 150 nm. Moreover, 5-50 mass% is preferable normally, and, as for the solid content concentration of the polymer emulsion obtained, 10-40 mass% is more preferable, This can be suitably selected according to use conditions, storage conditions, etc.
[0105]
Although the said hydrophilic group containing block copolymer emulsion may be used independently, it is also possible to use together with another polymer. That is, an antistatic polymer obtained by using a hydrophilic group-containing block copolymer in combination with another polymer can be used as an antistatic agent for a substrate such as a fibrous substance or a normal polymer. As a method for producing an antistatic polymer by using a hydrophilic group-containing block copolymer together with another polymer, (a) a method of blending an emulsion of a hydrophilic group-containing block copolymer and another polymer, ( b) An antistatic polymer can be obtained by emulsifying various known polymers using a hydrophilic group-containing block copolymer emulsion as an emulsifier.
[0106]
There is no restriction | limiting in particular as an emulsion of the other polymer of said (a), The well-known polymer emulsion is used. Preferred emulsions include urethane emulsions, acrylic emulsions, epoxy emulsions, polyester emulsions, polystyrene emulsions and the like, and these may be used alone or in combination of two or more. There is no particular limitation on the method of obtaining the antistatic polymer by emulsifying various known polymers using the (b) hydrophilic group-containing block copolymer emulsion as an emulsifier, but the following two methods are available. preferable.
(1) A method of obtaining an emulsion of the polymer by emulsifying various polymers using the hydrophilic group-containing block copolymer emulsion as an emulsifier (referred to as a polymer re-emulsification method). (2) Known emulsion polymerization, such as emulsifying a known monomer in the presence of a hydrophilic group-containing block copolymer emulsion, water and, optionally, a solvent, and then polymerizing the monomer with a radical initiator or the like. To obtain a polymer emulsion (referred to as emulsion polymerization method)
[0107]
In the antistatic block copolymer, the content ratio of the hydrophilic block is usually preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less in terms of solid content. When it exceeds 50 mass%, the stationary stability of the emulsion of an antistatic polymer may deteriorate.
[0108]
The antistatic agent is not particularly limited and may be used in combination with other antistatic agents. Such other antistatic agents are not particularly limited, but preferred are nonionic compounds having a polyoxyethylene or polyoxypropylene skeleton, cation compounds having a quaternary nitrogen structure, other sulfone groups, carboxylic acids. And anionic compounds having an anionic functional group such as a group or a phosphate group. In addition, the hydrophilic group-containing block copolymer emulsion and the like can be used by mixing additives such as a lubricant, a coating property improver, a thickener, an antioxidant, and an ultraviolet absorber as necessary. .
[0109]
-Other ingredients-
As other components in the toner image-receiving layer, various additives added for the purpose of improving the thermodynamic properties of the toner image-receiving layer, such as a release agent, a plasticizer, a colorant, a filler, a crosslinking agent, and a charge control agent. Other additives such as an agent, an emulsion and a dispersion are mentioned.
[0110]
--- Mold release agent--
The release agent is blended in the toner image receiving layer in order to prevent the toner image receiving layer from being offset. The release agent used in the present invention is heated and melted at the fixing temperature, deposited on the surface of the toner image-receiving layer, unevenly distributed on the surface of the toner image-receiving layer, and further cooled and solidified to be released onto the surface of the toner image-receiving layer. The type is not limited as long as it forms a layer of the mold material.
Examples of the release agent exhibiting such effects include at least one release agent selected from silicone compounds, fluorine compounds, waxes, and matting agents. Preferably, at least one release agent selected from the group consisting of silicone oil, polyethylene wax, carnauba wax, and silicone particles and polyethylene wax particles is used.
[0111]
As the mold release agent, for example, compounds described in “Summary of properties and applications of revised wax” by Kosho Shobo and the Silicone Handbook published by Nikkan Kogyo Shimbun, Inc. can be used. JP-B-59-38581, JP-B-4-32380, Japanese Patent Nos. 2838498, 2949558, JP-A-50-117433, 52-52640, 57-148755, 61-62056. 61-62057, 61-118760, JP-A-2-42451, 3-41465, 4-212175, 4-214570, 4-263267, 5-34966, 5-119514, 6-59502, 6-161150, 6-175396, 6-219040, 6-230600, 6-295093, 7-36210, 7 -43940, 7-56387, 7-56390, 7-64335, 7-199682, 7-223362 7-287413, 8-184992, 8-227180, 8-248671, 8-248799, 8-248801, 8-278663, 9-152939, 9 -160278, 9-185181, 9-319139, 9-319143, 10-20549, 10-48889, 10-198069, 10-207116, 11-2917 No. 11-44969, No. 11-65156, No. 11-73049, No. 11-194542, and the silicone compounds, fluorine compounds, and waxes used in the toners are also preferably used. . Further, a plurality of these compounds can be used in combination.
[0112]
Specifically, silicone-based compounds include non-modified silicone oils (specifically, dimethylsiloxane oil, methylhydrogen silicone oil, phenylmethyl silicone oil, amino-modified silicone oil, carboxy-modified silicone oil, Nord modified silicone oil, vinyl modified silicone oil, epoxy modified silicone oil, polyether modified silicone oil, silanol modified silicone oil, methacryl modified silicone oil, mercapto modified silicone oil, alcohol modified silicone oil, fluorine modified silicone oil, silicone rubber, silicone Fine particles, silicone-modified resin (specifically, olefin resin, polyester resin, vinyl resin, polyamide resin, Loose resin, phenoxy resin, vinyl chloride-vinyl acetate resin, urethane resin, acrylic resin, styrene-acrylic resin or a compound obtained by modifying these copolymer resins with silicone), reactive silicone compound (specifically, addition reaction type) , Peroxide curable type, ultraviolet curable type, etc.).
[0113]
Examples of the fluorine compound include fluorine oil, fluorine rubber, fluorine-modified resin, fluorine sulfonic acid compound, fluorosulfonic acid, fluorine acid compound or salt thereof (specifically, anhydrous hydrofluoric acid, dilute hydrofluoric acid, borohydrofluoric acid, Zinc borofluoride, nickel borofluoride, tin borofluoride, lead borofluoride, copper borofluoride, silicofluoric acid, potassium fluorotitanate, perfluorocaprylic acid, ammonium perfluorooctanoate, etc., inorganic fluoride (specifically Aluminum fluoride, potassium silicofluoride, potassium fluoride zirconate, zinc fluoride tetrahydrate, calcium fluoride, lithium fluoride, barium fluoride, tin fluoride, potassium fluoride, potassium acid fluoride, fluoride Magnesium, fluorinated titanic acid, fluorinated zirconic acid, ammonium hexafluorophosphate, hexafluoride Potassium phosphate, etc.), and the like.
[0114]
Examples of the wax include synthetic hydrocarbons, modified waxes, hydrogenated waxes, natural waxes, and the like.
[0115]
Examples of the synthetic hydrocarbon include polyethylene wax, polypropylene wax, Fischer-Tropsch wax, acid amide compounds, and acid imide compounds (specifically, stearamide, phthalic anhydride imide, and the like).
[0116]
Examples of the modified wax include amine-modified polypropylene, acrylic acid-modified wax, fluorine-modified wax, olefin-modified wax, urethane-type wax, and alcohol-type wax.
[0117]
Examples of the hydrogenated wax include hydrogenated castor oil, castor oil derivatives, stearic acid, lauric acid, myristic acid, palmitic acid, behenic acid, sebacic acid, undecylenic acid, heptylic acid, maleic acid, highly maleated oil, and blown oil. , Cyclopentadiened oil, and the like.
[0118]
The natural wax is preferably at least one selected from vegetable wax, animal wax, mineral wax and petroleum wax.
[0119]
Examples of the plant wax include carnauba wax (commercially available products such as EMUSTAR-0413 manufactured by Nippon Seiki, Cerosol 524 manufactured by Chukyo Yushi), castor oil (refined castor oil manufactured by Ito Oil Co., Ltd. as a commercial product), rapeseed oil, large Examples include bean oil, wax, cotton wax, rice wax, sugarcane wax, candelilla wax, Japan wax, jojoba oil, and the like. Among these, in particular, it has an excellent offset resistance, adhesion resistance, paper permeability, glossiness, is resistant to cracking, and can provide an electrophotographic image-receiving sheet capable of forming a high-quality image. Is particularly preferably a carnauba wax having a temperature of 70 to 95 ° C.
Examples of the animal wax include lanolin, spermaceti, stew wax (whale oil), and wool wax.
[0120]
Examples of the mineral wax include, for example, montan wax, montan ester wax, ozokerite, ceresin, fatty acid ester (commercially available products are Sansizer DOA, AN-800, DINA, DIDA, DOZ, DOS, TOTM, TITM manufactured by Shin Nippon Rika). , E-PS, nE-PS, E-PO, E-4030, E-6000, E-2000H, E-9000H, TCP, C-1100, etc.). Among these, in particular, it has an excellent anti-offset property, anti-adhesion property, paper passing property, glossiness, is resistant to cracking, and can provide an electrophotographic image-receiving sheet capable of forming a high-quality image. Is particularly preferably a montan wax of carnauba wax having a temperature of 70 to 95 ° C.
[0121]
Examples of the petroleum wax include paraffin wax, microcrystalline wax, and petrolatum.
[0122]
Content (g / m) of the natural wax in the toner image-receiving layer (surface)²) As 0.1 to 4 g / m²Is preferably 0.2 to 2 g / m²Is preferred.
The content is 0.1 g / m²If it is less than 4 g / m, the offset resistance and adhesion resistance may be particularly insufficient.²If it exceeds 1, the amount of wax is too large, and the image quality of the formed image may be inferior.
The melting point (° C.) of the natural wax is preferably 70 to 95 ° C., more preferably 75 to 90 ° C., particularly in terms of offset resistance and paper passing properties.
[0123]
Examples of the matting agent include various known ones. Solid particles used as a matting agent can be classified into inorganic particles and organic particles. Specific examples of the material for the inorganic matting agent include oxides (for example, silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide), alkaline earth metal salts (for example, barium sulfate, calcium carbonate, magnesium sulfate), halogens Examples include silver halide (eg, silver chloride, silver bromide) and glass.
[0124]
Examples of the inorganic matting agent include West German Patent 2529321, British Patent 760775, 1260772, U.S. Patent 1201905, 2192241, 3030562, 3030649, 3257206, 3322555, and 3353958. No. 3,370,951, No. 3,411,907, No. 3,437,484, No. 3523022, No. 3,615,554, No. 3,635,714, No. 3769020, No. 40212245, and No. 4029504.
[0125]
The material of the organic matting agent includes starch, cellulose ester (for example, cellulose acetate propionate), cellulose ether (for example, ethyl cellulose) and synthetic resin. The synthetic resin is preferably water-insoluble or poorly water-soluble. Examples of water-insoluble or poorly water-soluble synthetic resins include poly (meth) acrylic acid esters (for example, polyalkyl (meth) acrylate, polyalkoxyalkyl (meth) acrylate, polyglycidyl (meth) acrylate), poly (meth) Includes acrylamide, polyvinyl ester (eg, polyvinyl acetate), polyacrylonitrile, polyolefin (eg, polyethylene), polystyrene, benzoguanamine resin, formaldehyde condensation polymer, epoxy resin, polyamide, polycarbonate, phenol resin, polyvinyl carbazole and polyvinylidene chloride .
You may use the copolymer which combined the monomer used for the above polymer.
[0126]
In the case of the copolymer, a small amount of hydrophilic repeating units may be contained. Examples of the monomer forming the hydrophilic repeating unit include acrylic acid, methacrylic acid, α, β-unsaturated dicarboxylic acid, hydroxyalkyl (meth) acrylate, sulfoalkyl (meth) acrylate and styrene sulfonic acid.
Examples of the organic matting agent include British Patent No. 1055713, U.S. Patent No. 1,939,213, No. 2221873, No. 2,268,662, No. 2322037, No. 2376005, No. 233911, No. 2701245, No. 2992101, No. 3079257, Nos. 3,262,782, 3,443,946, 3,516,832, 3,539,344, 3,591,379, 3,754,924, 3,767,448, JP-A-49-106821, JP-A-57-14835 What has been described.
Two or more kinds of solid particles may be used in combination. The average particle size of the solid particles is, for example, preferably 1 to 100 μm, and more preferably 4 to 30 μm. The amount of solid particles used is 0.01 to 0.5 g / m.²Is preferred, 0.02-0.3 g / m²Is more preferable.
[0127]
As the release agent added to the toner image-receiving layer, these derivatives, oxides, purified products, and mixtures can also be used. Moreover, these may have a reactive substituent.
[0128]
The melting point (° C.) of the release agent is preferably 70 to 95 ° C., and more preferably 75 to 90 ° C., particularly in terms of offset resistance and paper passing properties.
The release agent is particularly preferably a water-dispersed release agent from the viewpoint of compatibility when an aqueous thermoplastic resin is used as the thermoplastic resin of the toner image receiving layer.
[0129]
The content of the release agent is preferably 0.1 to 10% by mass, more preferably 0.3 to 8.0% by mass, and further 0.5 to 5.0% by mass with respect to the total amount of the toner image-receiving layer. preferable.
[0130]
-Plasticizer-
As the plasticizer, known plasticizers for resins can be used without particular limitation. The plasticizer has a function of adjusting the flow or softening of the toner image-receiving layer by heat and / or pressure when fixing the toner.
Examples of the plasticizer include "Chemical Handbook" (edited by the Chemical Society of Japan, Maruzen), "Plasticizer -Theory and Application-" (written by Koichi Murai, Koshobo), "Research on plasticizer", "Research on plasticizer" “Lower” (edited by Polymer Chemistry Association), “Handbook Rubber / Plastic Compounded Chemicals” (edited by Rubber Digest Co., Ltd.), etc.
[0131]
Some of the plasticizers are described as high-boiling organic solvents and thermal solvents. For example, JP-A-59-83154, 59-178451, 59-178453, and 59-178454. 59-178455, 59-178457, 62-174754, 62-245253, 61-209444, 61-200538, 62-8145, 62-9348, 62-30247, 62-136646, 62-174754, 62-245253, 61-209444, 61-200538, 62-8145, 62-9348, 62- Esters such as those described in publications such as 30247, 62-136646, and JP-A-2-235694 (examples) For example, phthalic acid esters, phosphoric acid esters, fatty acid esters, abietic acid esters, adipic acid esters, sebacic acid esters, azelaic acid esters, benzoic acid esters, butyric acid esters, epoxidized fatty acid esters , Glycolic acid esters, propionic acid esters, trimellitic acid esters, citric acid esters, sulfonic acid esters, carboxylic acid esters, succinic acid esters, maleic acid esters, fumaric acid esters, phthalic acid esters And stearic acid esters), amides (for example, fatty acid amides, sulfoamides, etc.), ethers, alcohols, lactones, polyethyleneoxy compounds and the like.
The plasticizer can be used by mixing with a resin.
[0132]
A relatively low molecular weight polymer can be used as the plasticizer. In this case, the molecular weight of the plasticizer is preferably lower than the molecular weight of the binder resin to be plasticized, and the molecular weight is preferably 15000 or less, more preferably 5000 or less. In the case of a polymer plasticizer, the polymer is preferably the same type as the binder resin to be plasticized. For example, a low molecular weight polyester is preferable for plasticizing a polyester resin. Furthermore, oligomers can also be used as plasticizers. In addition to the compounds listed above, commercially available products include, for example, Adeka Sizer PN-170 and PN-1430 manufactured by Asahi Denka Kogyo; P. HALL products PARAPLEX-G-25, G-30, G-40; Rika Hercules products ester gum 8L-JA, ester R-95, pentalin 4851, FK115, 4820, 830, Louisol 28-JA, picolastic A75, pico Examples include Tex LC and Crystallex 3085.
[0133]
The plasticizer relieves stress and strain (physical strain such as elastic force and viscosity, strain due to mass balance of molecules, binder main chain, pendant, etc.) generated when toner particles are embedded in the toner image receiving layer. Can be used arbitrarily to The plasticizer may be in a micro-dispersed state in the toner image-receiving layer, may be in a phase-separated microscopically in a sea-island shape, or may be in a sufficiently mixed and dissolved state with other components such as a binder.
The content of the plasticizer in the toner image-receiving layer is preferably 0.001 to 90% by mass, more preferably 0.1 to 60% by mass, and still more preferably 1 to 40% by mass.
The plasticizer adjusts smoothness (improves transportability due to reduced frictional force), improves fixing unit offset (detachment of toner and layers from the fixing unit), adjusts curl balance, and adjusts charging (toner electrostatic image It may be used for the purpose of forming).
[0134]
--Colorant--
Examples of the colorant include fluorescent whitening agents, white pigments, colored pigments, and dyes.
The fluorescent whitening agent is a compound that absorbs in the near ultraviolet region and emits fluorescence at 400 to 500 nm, and various known fluorescent whitening agents can be used without particular limitation. Examples of the optical brightener include K.I. Preferable examples include the compounds described in “The Chemistry of Synthetic Dies” edited by Veen Rataraman, Vol. Specific examples include stilbene compounds, coumarin compounds, biphenyl compounds, benzoxazoline compounds, naphthalimide compounds, pyrazoline compounds, carbostyryl compounds, and the like. Examples thereof include white fur fur PSN, PHR, HCS, PCS, B manufactured by Sumitomo Chemical; UVITEX-OB manufactured by Ciba-Geigy.
[0135]
As the white pigment, an inorganic pigment (for example, titanium oxide, calcium carbonate, etc.) in the filler section described later can be used. Examples of the colored pigment include various pigments and azo pigments described in JP-A-63-44653 (for example, azo lake; carmine 6B, red 2B, insoluble azo; monoazo yellow, disazo yellow, pyrazolo orange, vulcan orange, condensation) Azo series; chromophthal yellow, chromophthal red), polycyclic pigments (for example, phthalocyanine series; copper phthalocyanine blue, copper phthalocyanine green, dioxazine series; dioxazine violet, isoindolinone series; isoindolinone yellow, slen series; Perylene, perinone, flavantron, thioindigo, lake pigment (eg, malachite green, rhodamine B, rhodamine G, Victoria blue B) or inorganic pigment (eg, oxide, titanium dioxide, bengara, sulfate; precipitated barium sulfate Calcium precipitated carbonates, silicates; carbonates hydrous silicates, anhydrous silicates, metal powders; aluminum powder, bronze powder, zinc powder, carbon black, chrome yellow, Prussian blue and the like.
These may be used alone or in combination of two or more. Among these, titanium oxide is particularly preferable as the pigment.
[0136]
Various known dyes can be used as the dye.
Examples of oil-soluble dyes include anthraquinone compounds and azo compounds.
Specific examples of water-insoluble dyes include C.I. I. Vat violet 1, C.I. I. Vat violet 2, C.I. I. Vat violet 9, C.I. I. Vat violet 13, C.I. I. Vat violet 21, C.I. I. Vat Blue 1, C.I. I. Vat Blue 3, C.I. I. Vat Blue 4, C.I. I. Vat Blue 6, C.I. I. Vat Blue 14, C.I. I. Vat Blue 20, C.I. I. Vat dyes such as Vat Blue 35; I. Dispers Violet 1, C.I. I. Disperse Violet 4, C.I. I. Disperse Violet 10, C.I. I. Disperse Blue 3, C.I. I. Disperse Blue 7, C.I. I. Disperse dyes such as Disperse Blue 58; I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 21, C.I. I. Solvent Violet 27, C.I. I. Solvent Blue 11, C.I. I. Solvent Blue 12, C.I. I. Solvent Blue 25, C.I. I. And oil-soluble dyes such as Solvent Blue 55.
A colored coupler used in silver salt photography can also be preferably used.
[0137]
Content of the colorant in the toner image receiving layer (surface) (g / m²) As 0.1 to 8 g / m²Is preferably 0.5 to 5 g / m²Is more preferable.
The content of the colorant is 0.1 g / m²If it is less than 1, the light transmittance in the toner image-receiving layer is increased, while the colorant content is 8 g / m.²Exceeding may cause poor handling such as cracking and adhesion resistance.
[0138]
--Filler--
As said filler, an organic or inorganic filler is mentioned, A well-known thing can be used as a reinforcing agent for binder resin, a filler, and a reinforcing material. The filler should be selected with reference to "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest Co., Ltd.), "New Edition Plastic Compounding Agent Basics and Applications" (Taiseisha), "Filler Handbook" (Taiseisha) Can do.
Moreover, various inorganic fillers (or pigments) can be used as the filler. Examples of the inorganic pigment include silica, alumina, titanium dioxide, zinc oxide, zirconium oxide, mica-like iron oxide, lead white, lead oxide, cobalt oxide, strontium chromate, molybdenum pigment, smectite, magnesium oxide, calcium oxide, carbonic acid Examples include calcium and mullite. As the filler, silica and alumina are particularly preferable. These fillers may be used alone or in combination of two or more. The filler preferably has a small particle size. If the particle size is large, the surface of the toner image-receiving layer tends to be roughened.
[0139]
The silica includes spherical silica and amorphous silica. The silica can be synthesized by a dry method, a wet method, or an airgel method. The surface of the hydrophobic silica particles may be surface-treated with a trimethylsilyl group or silicone. As silica, colloidal silica is preferable. The average particle diameter of silica is preferably 200 to 5000 nm.
The silica is preferably porous. The average pore diameter of the porous silica is preferably 4 to 120 nm, and more preferably 4 to 90 nm. The average pore volume per mass of the porous silica is preferably 0.5 to 3 ml / g.
[0140]
The alumina includes anhydrous alumina and alumina hydrate. As the crystal form of anhydrous alumina, α, β, γ, δ, ζ, η, θ, κ, ρ, or χ can be used. Alumina hydrate is preferred over anhydrous alumina. As the alumina hydrate, a monohydrate or a trihydrate can be used. Monohydrates include pseudoboehmite, boehmite and diaspore. Trihydrates include dibsite and bayerite. The average particle diameter of the alumina is preferably 4 to 300 nm, and more preferably 4 to 200 nm. Alumina is preferably porous. The average pore diameter of the porous alumina is preferably 50 to 500 nm. The average pore volume per mass of the porous alumina is preferably about 0.3 to 3 ml / g.
[0141]
The alumina hydrate can be synthesized by a sol-gel method in which ammonia is added to an aluminum salt solution to precipitate or a method in which an alkali aluminate is hydrolyzed. Anhydrous alumina can be obtained by dehydrating alumina hydrate by heating.
The filler is preferably 5 to 2000% by mass based on the dry mass of the binder in the layer to be added.
[0142]
-Crosslinking agent-
The cross-linking agent can be blended in order to adjust the storage stability, thermoplasticity, etc. of the toner image-receiving layer. As such a crosslinking agent, a compound having two or more known reactive groups in the molecule as an reactive group such as epoxy group, isocyanate group, aldehyde group, active halogen group, active methylene group, acetylene group and the like is used.
[0143]
As the cross-linking agent, a compound having two or more groups capable of forming a bond by hydrogen bond, ionic bond, coordination bond or the like can be used. As the crosslinking agent, known compounds can be used as coupling agents for resins, curing agents, polymerization agents, polymerization accelerators, coagulants, film-forming agents, film-forming aids, and the like. Examples of coupling agents include, for example, chlorosilanes, vinyl silanes, epoxy silanes, aminosilanes, alkoxyaluminum chelates, titanate coupling agents, etc. "Handbook Rubber / Plastic Compounding Chemicals" (Rubber Digest Co., Ltd.) Ed) and the like can be used.
[0144]
-Charge control agent-
The toner image-receiving layer of the present invention preferably contains a charge adjusting agent in order to adjust toner transfer, adhesion, etc., and to prevent charge adhesion of the toner image-receiving layer.
Conventionally known various charge control agents can be used as the charge control agent. Examples of such a charge control agent include cationic surfactants, surfactants such as anionic surfactants, amphoteric surfactants, and nonionic surfactants, as well as polymer electrolytes and conductive metal oxides. Things can be used. For example, quaternary ammonium salts, polyamine derivatives, cation-modified polymethyl methacrylate, cationic antistatic agents such as cation-modified polystyrene, anionic antistatic agents such as alkyl phosphates and anionic polymers, fatty acid esters, polyethylene oxide, etc. Nonionic antistatic agents may be mentioned, but are not limited thereto.
[0145]
When the toner has a negative charge, for example, a cation or nonion is preferable as the charge adjusting agent to be blended in the toner image receiving layer.
Examples of the conductive metal oxide include ZnO and TiO.₂, SnO₂, Al₂O₃, In₂O₃, SiO₂, MgO, BaO, MoO₃Etc. These conductive metal oxides may be used alone or in combination with these composite oxides. Further, the metal oxide may further contain a different element, for example, Al, In, etc., TiO 2 with respect to ZnO.₂Nb, Ta, etc., SnO₂Can contain (doping) Sb, Nb, a halogen element, or the like.
[0146]
-Other additives-
The material that can be used in the toner image-receiving layer of the present invention can contain various additives for improving the stability of the output image and improving the stability of the toner image-receiving layer itself. Examples of the additive include various known antioxidants, antioxidants, deterioration inhibitors, ozone deterioration inhibitors, ultraviolet absorbers, metal complexes, light stabilizers, preservatives, fungicides, and the like.
[0147]
Examples of the antioxidant include a chroman compound, a coumaran compound, a phenol compound (eg, hindered phenol), a hydroquinone derivative, a hindered amine derivative, and a spiroindane compound. The antioxidant is described in JP-A No. 61-159644.
[0148]
Examples of the antiaging agent include those described in “Handbook Rubber / Plastic Compounding Chemicals Revised 2nd Edition” (1993, Rubber Digest Co.) p76-121.
[0149]
Examples of the ultraviolet absorber include benzotriazole compounds (described in U.S. Pat. No. 3,533,794), 4-thiazolidone compounds (described in U.S. Pat. No. 3,352,681), benzophenone compounds (described in JP-A-46-2784), and Examples thereof include ultraviolet absorbing polymers (described in JP-A-62-260152).
[0150]
Examples of the metal complex include U.S. Pat. Nos. 4,241,155, 4,425,018 and 4,254,195, JP-A-61-88256, JP-A-62-174741, JP-A-63-199248, JP-A-1-75568. Nos. 1 and 74272 are appropriate.
Further, ultraviolet absorbers and light stabilizers described in "Handbook Rubber / Plastic Compounding Chemicals Revised 2nd Edition" (1993, Rubber Digest Co., Ltd.) p122 to 137 are also preferably used.
[0151]
In addition, as described above, a known photographic additive can be added to the material that can be used for the toner image-receiving layer of the present invention, if necessary. Examples of the photographic additive include, for example, Research Disclosure Magazine (hereinafter abbreviated as RD) No. 17643 (December 1978), 18716 (November 1979) and 307105 (November 1989), and the corresponding parts are summarized below.

[0152]
The toner image-receiving layer of the present invention is provided by applying a coating solution containing a polymer used for the toner image-receiving layer on the support with a wire coater or the like and drying. The film forming temperature of the polymer used in the present invention is preferably room temperature or higher for storage before printing, and preferably 100 ° C. or lower for fixing toner particles.
[0153]
The toner image-receiving layer of the present invention has a coating weight after drying of, for example, 1 to 20 g / m.²Is preferably 4 to 15 g / m.²Is more preferable.
The thickness of the toner image-receiving layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 30 μm, and more preferably 2 to 20 μm.
[0154]
-Various properties of toner image-receiving layer-
The toner image receiving layer preferably has high whiteness. The whiteness is preferably 85% or more as measured by the method defined in JIS P 8123. Further, it is preferable that the spectral reflectance is 85% or more in the wavelength region of 440 nm to 640 nm, and the difference between the maximum spectral reflectance and the minimum spectral reflectance in the same wavelength region is within 5%. Furthermore, it is more preferable that the spectral reflectance is 85% or more in the wavelength region of 400 nm to 700 nm, and the difference between the maximum spectral reflectance and the minimum spectral reflectance in the same wavelength region is within 5%.
Further, as the whiteness, specifically, CIE 1976 (L^*a^*b^*) In color space, L^*The value is preferably 80 or more, more preferably 85 or more, and still more preferably 90 or more. The white color is preferably as neutral as possible. As the white color, L^*a^*b^*In space, (a^*)²+ (B^*)²The value of is preferably 50 or less, more preferably 18 or less, and still more preferably 5 or less.
[0155]
The toner image receiving layer preferably has high gloss. As the glossiness, the 45 ° glossiness is preferably 60 or more, more preferably 75 or more, and still more preferably 90 or more in the entire region from white without toner to black having the maximum density.
However, the glossiness is preferably 110 or less. If it exceeds 110, it becomes like metallic luster, which is not preferable as image quality.
In addition, the said glossiness can be measured based on JISZ8741.
[0156]
The toner image-receiving layer preferably has physical properties of one of the following items, more preferably a plurality of items, and most preferably all physical properties.
(1) The toner image-receiving layer has a Tg (glass transition temperature) of 30 ° C. or higher and a toner Tg + 20 ° C. or lower.
(2) The T1 / 2 (1/2 method softening point) of the toner image-receiving layer is 60 to 200 ° C., preferably 80 to 170 ° C. Here, the 1/2 method softening point is determined by using a specific apparatus and applying a predetermined extrusion load under a specific condition, and a preheating time at an initial set temperature (for example, 50 ° C.), for example, 300 After a second, the temperature is evaluated at a temperature that is a half of the difference between the piston stroke at the start and end of the outflow at each temperature when the temperature is increased at a predetermined constant speed.
(3) Tfb (outflow start temperature) of the toner image-receiving layer is 40 to 200 ° C., preferably, Tfb of the toner image-receiving layer is Tfb + 50 ° C. or less of the toner.
(4) The viscosity of the toner image-receiving layer is 1 × 10⁵The temperature at which CP becomes 40 ° C. or higher is lower than that of toner.
(5) The storage elastic modulus (G ′) at the fixing temperature of the toner image-receiving layer is 1 × 10²~ 1x10⁵Pa, loss elastic modulus (G ″) is 1 × 10²~ 1x10⁵Pa.
(6) The loss tangent (G ″ / G ′), which is the ratio between the loss elastic modulus (G ″) at the fixing temperature of the toner image-receiving layer and the storage elastic modulus (G ′), is 0.01 to 10.
(7) The storage elastic modulus (G ′) at the fixing temperature of the toner image-receiving layer is −50 to +2500 with respect to the storage elastic modulus (G ″) at the fixing temperature of the toner.
(8) The inclination angle of the molten toner on the toner image-receiving layer is 50 degrees or less, particularly 40 degrees or less.
The toner image-receiving layer preferably satisfies the physical properties disclosed in Japanese Patent No. 2788358, Japanese Patent Application Laid-Open Nos. 7-248637, 8-305067, and 10-239889.
[0157]
The physical property (1) can be measured by a differential scanning calorimeter (DSC). The physical properties (2) to (3) can be measured using, for example, a flow tester CFT-500 or 500D manufactured by Shimadzu Corporation. The physical properties (5) to (7) can be measured using a rotational rheometer (for example, a dynamic analyzer RADII manufactured by Rheometric). The physical property (8) can be measured by a method disclosed in JP-A-8-334916 using a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd.
[0158]
As the toner image-receiving layer, 1 × 10⁶~ 1x10¹⁵Ω / cm²It is preferable to have a surface electrical resistance in the range of (under conditions of 25 ° C. and 65% RH).
The surface resistance is 1 × 10⁶Ω / cm²If the ratio is less than 1, the amount of toner when the toner is transferred to the toner image-receiving layer is not sufficient, and the density of the obtained toner image tends to be low, while the surface electrical resistance is 1 × 10.¹⁵Ω / cm²Exceeding the amount of charge will generate more charge than necessary during transfer, the toner will not be transferred sufficiently, the image density will be low, and electrostatic charge will easily adhere to the electrophotographic image receiving sheet, and during copying, Misfeed, double feed, discharge mark, toner transfer missing, etc. may occur.
[0159]
The surface electrical resistance of the surface opposite to the toner image-receiving layer with respect to the support is 5 × 10.⁸~ 3.2 × 10¹⁰Ω / cm²1 × 10 is preferred⁹~ 1x10¹⁰Ω / cm²Is more preferable.
In the present invention, the surface electrical resistance is measured in accordance with JIS K 6911, the sample is conditioned for 8 hours or more in an environment of a temperature of 20 ° C. and a humidity of 65%, and under the same environment, R8340 manufactured by Advantest Corporation. Is used, and measurement is performed after 1 minute has passed after energization under the condition of an applied voltage of 100V.
[0160]
[Back layer]
In the electrophotographic image-receiving sheet of the present invention, the back layer is on the opposite side of the toner image-receiving layer from the support for the purpose of imparting backside output suitability, improving backside output image quality, improving curl balance, improving device passability, etc. Provided with the above-described surface roughness properties.
The back layer preferably contains the same water-dispersed resin as the toner image-receiving layer, particularly a soap-free water-dispersible polymer, and further contains colloidal silica.
As the colloidal silica, commercially available silica sol suspensions such as Ludox HS, Ludox AS (DuPont), SNOWTEX O, SNOWTEX C, SNOWTEX 20, etc. (Nissan Chemical Co., Ltd.) Etc. As for content of the said colloidal silica, 1-50 mass% is preferable with respect to the whole composition for back layers.
Although there is no restriction | limiting in particular as a color of the said back layer, When the image receiving sheet for electrophotography of this invention is a double-sided output type image receiving sheet which forms an image also in a back surface, it is preferable that a back layer is also white. The whiteness and the spectral reflectance are preferably 85% or more like the surface.
The thickness of the back layer is usually preferably from 0.1 to 10 μm.
[0161]
[Other layers]
Examples of the other layers include a surface protective layer, an adhesion improving layer, an intermediate layer, an undercoat layer, a cushion layer, a reflective layer, a tint adjusting layer, a storage stability improving layer, an adhesion preventing layer, an anti-curl layer, and a smooth layer. And the like. These layers may be composed of a single layer or may be composed of two or more layers.
[0162]
-Surface protective layer-
The surface protective layer is for the purpose of protecting the surface of the electrophotographic image-receiving sheet of the present invention, improving storage stability, improving handleability, imparting writability, improving instrument passability, imparting anti-offset properties, etc. It can be provided on the surface of the toner image-receiving layer. The surface protective layer may be a single layer or may be composed of two or more layers. In the surface protective layer, various thermoplastic resins, thermosetting resins, and the like can be used as a binder, and it is preferable to use the same type of resin as the toner image receiving layer. However, thermodynamic characteristics, electrostatic characteristics, and the like do not need to be the same as those of the toner image-receiving layer, and can be optimized.
[0163]
The surface protective layer may contain the various additives described above that can be used for the toner image-receiving layer. In particular, the surface protective layer may be blended with other additives such as a matting agent in addition to the release agent used in the present invention. In addition, as said mat agent, various well-known things are mentioned.
The outermost surface layer in the electrophotographic image-receiving sheet of the present invention (for example, the surface protective layer when a surface protective layer is formed) has good compatibility with the toner in terms of fixing properties. preferable. Specifically, the contact angle with the melted toner is preferably, for example, 0 to 40 degrees.
[0164]
-Adhesion improvement layer, etc.-
The adhesion improving layer is preferably formed for the purpose of improving the adhesion between the support and the toner image receiving layer in the electrophotographic image receiving sheet of the present invention. The above-mentioned various additives can be blended in the adhesion improving layer, and it is particularly preferable to blend a crosslinking agent. The electrophotographic image-receiving sheet of the present invention preferably further comprises a cushion layer or the like between the adhesion improving layer and the toner image-receiving layer in order to improve toner acceptability.
[0165]
-Intermediate layer-
The intermediate layer is formed, for example, between the support and the adhesion improving layer, between the adhesion improving layer and the cushion layer, between the cushion layer and the toner image receiving layer, and between the toner image receiving layer and the storage stability improving layer. Can do. Of course, in the case of an electrophotographic image-receiving sheet comprising a support, a toner image-receiving layer, and an intermediate layer, the intermediate layer can be present, for example, between the support and the toner image-receiving layer.
[0166]
The thickness of the electrophotographic image-receiving sheet of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 50 to 350 μm is preferable, and 100 to 280 μm is more preferable.
[0167]
(toner)
The electrophotographic image-receiving sheet of the present invention is used by allowing a toner image-receiving layer to receive toner during printing or copying.
The toner contains at least a binder resin and a colorant, and if necessary, a release agent and other components.
[0168]
-Toner binder resin-
Examples of the binder resin include styrenes such as styrene and parachlorostyrene; vinyl esters such as vinyl naphthalene, vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate. Class: methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate , Methylene aliphatic carboxylic acid esters such as ethyl methacrylate and butyl methacrylate; vinyl nitriles such as acrylonitrile, methacrylonitrile and acrylamide; vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc. Nyl ethers; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; single weights of vinyl monomers such as vinyl carboxylic acids such as methacrylic acid, acrylic acid and cinnamic acid Copolymers, copolymers thereof, and various polyesters can be used, and various waxes can be used in combination.
Among these resins, it is preferable to use resins of the same system as those used for the toner image receiving layer of the present invention.
[0169]
-Toner Colorant-
As the colorant, those usually used in toners can be used without limitation. For example, carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone. Orange, Vulcan Orange, Watch Young Red, Permanent Red, Brilliantamine 3B, Brilliantamine 6B, Daypon Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Examples include various pigments such as oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, and malachite green oxalelate. Acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenyl Examples include various dyes such as methane, diphenylmethane, thiazine, thiazole, and xanthene. These colorants may be used alone or in combination of two or more.
The content of the colorant is preferably in the range of 2 to 8% by mass. If the content of the colorant is 2% by mass or more, the coloring power is not weakened. On the other hand, if it is 8% by mass or less, the transparency is not impaired, which is preferable.
[0170]
-Toner release agent-
As the mold release agent, all known waxes can be used in principle, but polar waxes containing nitrogen such as relatively low molecular weight high crystalline polyethylene wax, Fischer-Tropsch wax, amide wax, urethane compound, etc. Etc. are particularly effective. The molecular weight of the polyethylene wax is preferably 1000 or less, and more preferably 300 to 1000.
[0171]
The compound having a urethane bond is suitable because even if it has a low molecular weight, the solid state can be maintained and the melting point can be set high for the molecular weight due to the strength of cohesive force due to the polar group. The preferred range of molecular weight is 300-1000. The raw materials are a combination of diisocyanate compounds and monoalcohols, a combination of monoisocyanic acid and monoalcohol, a combination of dialcohols and monoisocyanic acid, a combination of trialcohols and monoisocyanic acid, triisocyanic acid Various combinations such as combinations of compounds and monoalcohols can be selected, but in order not to increase the molecular weight, it is preferable to combine a compound of a polyfunctional group and a monofunctional group, and an equivalent functional group amount. It is important to ensure that
[0172]
Specific examples of the raw material compound include monoisocyanate compounds such as dodecyl isocyanate, phenyl isocyanate and derivatives thereof, naphthyl isocyanate, hexyl isocyanate, benzyl isocyanate, butyl isocyanate, and allyl isocyanate. It is done.
Examples of diisocyanate compounds include tolylene diisocyanate, 4,4'diphenylmethane diisocyanate, toluene diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, 4-methyl-m-phenylene diisocyanate, and isophorone diisocyanate. Can be mentioned.
As the monoalcohol, it is possible to use very common alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, and heptanol.
Among the raw material compounds, as the dialcohols, a number of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol; as the trialcohols, trimethylolpropane, triethylolpropane, trimethanolethane, etc. can be used. However, it is not necessarily limited to this range.
[0173]
These urethane compounds can be mixed with a resin and a colorant at the time of kneading and used as a kneaded and pulverized toner as in a normal release agent. Also, when used in the emulsion polymerization aggregation melting toner described above, it is dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid or a polymer base, and heated to a melting point or higher to produce a homogenizer or pressure discharge. A fine dispersion is obtained by applying strong shearing with a mold disperser to prepare a release agent particle dispersion of 1 μm or less, which can be used together with a resin particle dispersion, a colorant dispersion and the like.
[0174]
-Toner and other components-
Further, the toner of the present invention may contain other components such as an internal additive, a charge control agent, and inorganic fine particles. As the internal additive, a magnetic material such as a metal such as ferrite, magnetite, reduced iron, cobalt, nickel, manganese, an alloy, or a compound containing these metals can be used.
[0175]
As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments may be used. it can. A material that is difficult to dissolve in water is preferable from the viewpoint of controlling the ionic strength that affects the stability during aggregation and melting and reducing wastewater contamination.
[0176]
Examples of the inorganic fine particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and the like. Usually, all external additives on the toner surface are used. It is preferable to use by dispersing with a molecular base.
[0177]
Furthermore, a surfactant can be used for emulsion polymerization, seed polymerization, pigment dispersion, resin particle dispersion, release agent dispersion, aggregation, and stabilization thereof. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, cationic surfactants such as amine salt type and quaternary ammonium salt type, polyethylene glycol type, alkylphenol It is also effective to use a nonionic surfactant such as an ethylene oxide adduct system or a polyhydric alcohol system in combination. As a dispersing means at that time, a general means such as a rotary shear type homogenizer, a ball mill having a media, a sand mill, a dyno mill or the like can be used.
[0178]
An external additive may be further added to the toner as necessary. Examples of the external additive include inorganic powder and organic particles. Examples of the inorganic particles include SiO.₂TiO₂, Al₂O₃, CuO, ZnO, SnO₂, Fe₂O₃, MgO, BaO, CaO, K₂O, Na₂O, ZrO₂, CaO · SiO₂, K₂O. (TiO₂)_n, Al₂O₃・ 2SiO₂, CaCO₃, MgCO₃, BaSO₄, MgSO₄Etc. can be illustrated. Moreover, as said organic particle, resin powder, such as powders, such as fatty acid or its derivative (s), these metal salts, fluorine resin, a polyethylene resin, an acrylic resin, can be used. For example, the average particle size of these powders is preferably 0.01 to 5 μm, and more preferably 0.1 to 2 μm.
[0179]
The method for producing the toner is not particularly limited, and (i) a step of forming an aggregated particle in a dispersion obtained by dispersing resin particles to prepare an aggregated particle dispersion, (ii) in the aggregated particle dispersion. A step of adding and mixing a fine particle dispersion in which fine particles are dispersed to adhere the fine particles to the aggregated particles to form the adhered particles; and (iii) heating and fusing the adhered particles to form toner particles. It is preferable that the toner is manufactured by a toner manufacturing method including the steps.
[0180]
-Toner physical properties-
The volume average particle diameter of the toner of the present invention is preferably from 0.5 μm to 10 μm.
If the volume average particle diameter of the toner is too small, there may be an adverse effect on toner handling (replenishability, cleaning properties, fluidity, etc.), and particle productivity may be reduced. On the other hand, if the volume average particle diameter of the toner is too large, the image quality and resolution due to graininess and transferability may be adversely affected.
The toner of the present invention preferably satisfies the above-mentioned toner volume average particle size range, and the volume average particle size distribution index (GSDv) is preferably 1.3 or less.
The ratio (GSDv / GSDn) of the volume average particle size distribution index (GSDv) to the number average particle size distribution index (GSDn) is preferably 0.95 or more.
In addition, the toner of the present invention satisfies the volume average particle diameter range of the toner, and the average value of the shape factor represented by the following formula is preferably 1.00 to 1.50.
Shape factor = (π × L²) / (4 × S)
(However, L represents the maximum length of toner particles, and S represents the projected area of toner particles.)
When the toner satisfies the above conditions, it is effective for image quality, particularly graininess, and resolution. Also, it is difficult to cause omission and blur due to transfer, and handling properties are hardly adversely affected even if the average particle size is not small. Become.
[0181]
The storage elastic modulus G ′ (measured at an angular frequency of 10 rad / sec) at 150 ° C. of the toner itself is suitably 10 to 200 Pa from the viewpoint of improving the image quality and preventing the offset property in the fixing process.
[0182]
(Image forming method)
In the image forming method of the present invention, it is preferable to use a cooling / peeling type belt fixing type smoothing processing machine having a heating / pressurizing unit, a cooling unit, and a cooling / peeling unit as the heat / pressure treatment.
It is preferable that the heating and pressurizing unit is heated and pressurized to a temperature equal to or higher than the softening point of the thermoplastic resin in the image forming layer, cooled, and then peeled off from the belt member in the heating and pressing unit (cooling peeling process).
The heating and pressing means of the cooling-peeling belt type smoothing processor is not particularly limited, and examples thereof include a combination of a heating roller, a pressing roller, and an endless belt. Although it does not restrict | limit especially as said cooling means, For example, a cooling device, a heat sink, etc. which can ventilate cool air and can adjust cooling temperature etc. are used.
[0183]
It is preferable to apply pressure when the image forming material is brought into contact with the heating and pressurizing unit of the cooling and peeling type belt type smoothing processor. Although there is no restriction | limiting in particular as this pressurization method, It is preferable to apply nip pressure. The nip pressure is 1 to 100 kg / cm from the viewpoint of forming an image having excellent water resistance and surface smoothness and good gloss.²Is preferred, 5-30 kg / cm²Is more preferable. Further, the heating in the heating and pressurizing means is a temperature equal to or higher than the softening point of the thermoplastic resin in the image forming layer, and varies depending on the thermoplastic resin used, but is usually preferably 80 ° C. or higher and 200 ° C. or lower. The cooling temperature in the cooling means is preferably 80 ° C. or lower, more preferably 20 to 80 ° C., at which the thermoplastic resin layer in the image forming layer is sufficiently solidified.
[0184]
The surface of the fixing belt is preferably formed with a thin film made of at least one selected from the group consisting of silicone rubber, fluororubber, silicone resin, and fluororesin. Among them, an aspect in which a fluorocarbonsiloxane rubber layer having a uniform thickness is provided on the surface of the belt member, a silicone rubber layer having a uniform thickness is provided on the surface of the belt member, and the surface of the silicone rubber layer is provided. An embodiment in which a fluorocarbon siloxane rubber layer having a uniform thickness is provided.
[0185]
The fluorocarbon siloxane rubber preferably has a perfluoroalkyl ether group and / or a perfluoroalkyl group in the main chain.
Such a fluorocarbon siloxane rubber includes (A) a fluorocarbon siloxane having the following general formula (1) as a main component and an aliphatic unsaturated group, and (B) two or more ≡SiH groups in one molecule. Organopolysiloxane and / or fluorocarbon siloxane, wherein the content of the ≡SiH group is 1 to 4 times the molar amount of the aliphatic unsaturated group in the fluorocarbon siloxane rubber composition, (C) filling A cured product of a fluorocarbon siloxane rubber composition containing an agent and (D) an effective amount of a catalyst is preferably used.
[0186]
The (A) component fluorocarbon polymer is mainly composed of a fluorocarbon siloxane having a repeating unit represented by the following general formula (1) and has an aliphatic unsaturated group.
[0187]
[Chemical 1]

[0188]
Here, in the above formula (1), R¹⁰Is an unsubstituted or substituted monovalent hydrocarbon group having preferably 1 to 8 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 3 carbon atoms, particularly a methyl group. Is preferred. a and e are each 0 or 1, b and d are each an integer of 1 to 4, and c is an integer of 0 to 8. Moreover, x is an integer greater than or equal to 1, Preferably it is 10-30.
[0189]
Examples of the component (A) include those represented by the following formula (2).
[0190]
[Chemical 2]

[0191]
In the component (B), examples of the organopolysiloxane having an ≡SiH group include organohydrogenpolysiloxanes having at least two hydrogen atoms bonded to silicon atoms in the molecule.
[0192]
In the fluorocarbon siloxane rubber composition used in the present invention, when the fluorocarbon polymer as the component (A) has an aliphatic unsaturated group, the above-described organohydrogenpolysiloxane can be used as a curing agent. . That is, in this case, a cured product is formed by an addition reaction that occurs between an aliphatic unsaturated group in the fluorocarbon siloxane and a hydrogen atom bonded to a silicon atom in the organohydrogenpolysiloxane.
[0193]
As such organohydrogenpolysiloxane, various organohydrogenpolysiloxanes used in addition-curable silicone rubber compositions can be used.
[0194]
The above-mentioned organohydrogenpolysiloxane generally has at least one ≡SiH group, particularly 1 to 5 with respect to one aliphatic unsaturated hydrocarbon group in the fluorocarbon siloxane of component (A). It is suitable to mix | blend in such a ratio.
[0195]
Further, the fluorocarbon having an ≡SiH group may be a unit of the above formula (1) or R in the formula (1).¹⁰Is preferably a dialkylhydrogensiloxy group and the terminal is a ≡SiH group such as a dialkylhydrogensiloxy group or a silyl group, and examples thereof include those represented by the following formula (3).
[0196]
[Chemical Formula 3]

[0197]
As the filler of the component (C), various fillers used in general silicone rubber compositions can be used. For example, fumed silica, precipitated silica, carbon powder, titanium dioxide, aluminum oxide, quartz powder, reinforcing fillers such as talc, sericite and bentonite, fibrous fillers such as asbestos, glass fiber, organic fiber, etc. It can be illustrated.
[0198]
As the catalyst of the component (D), chloroplatinic acid, alcohol-modified chloroplatinic acid, complexes of chloroplatinic acid and olefin, platinum black or palladium, which are known as addition reaction catalysts, alumina, silica, carbon, etc. Examples are those supported on the above-mentioned carriers, complex of rhodium and olefin, group VIII element of periodic table such as chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst), rhodium (III) acetylacetonate, etc. However, these complexes are preferably used by being dissolved in a solvent such as an alcohol, ether, or hydrocarbon.
[0199]
In the fluorocarbon siloxane rubber composition used in the present invention, various compounding agents can be added as long as the object of the present invention to improve chemical resistance is not impaired. For example, diphenylsilane diol, low-polymerization degree molecular chain terminal hydroxyl-blocked dimethylpolysiloxane, dispersant such as hexamethyldisilazane, heat resistance improver such as ferrous oxide, ferric oxide, cerium oxide, iron octylate Further, colorants such as pigments can be blended as necessary.
[0200]
The belt member of the present invention is obtained by coating the surface of a heat-resistant resin or metal belt body with the fluorocarbon siloxane rubber composition, followed by heat curing. It can be diluted with a solvent such as fluoride or benzotrifluoride to obtain a coating solution, which can be applied by a general coating method such as spray coating, dip coating or knife coating. The temperature and time for heat curing can be selected as appropriate, and are selected according to the type of belt body and the manufacturing method, etc., in the range of normal temperature of 100 to 500 ° C. and time of 5 seconds to 5 hours.
[0201]
The thickness of the fluorocarbonsiloxane rubber layer formed on the surface of the belt member is not particularly limited, but is usually preferably 20 to 500 μm, more preferably 40 to 200 μm.
[0202]
As the surface roughness [arithmetic mean roughness (Ra)] of the belt member, 20 μm or less is preferable, and 5 μm or less is more preferable, particularly in that it is excellent in surface smoothness and can form an image having good gloss. 1 μm or less is more preferable. The arithmetic average roughness can be measured based on JIS B 0601, B 0651, B 0652.
[0203]
The method for forming an image on the electrophotographic image-receiving sheet of the present invention is not particularly limited as long as it is an electrophotographic method using a fixing belt, and any ordinary electrophotographic method can be applied.
For example, a color image can be preferably formed on the electrophotographic image-receiving sheet of the present invention. The color image can be formed using an electrophotographic apparatus capable of forming a full color image. A typical electrophotographic apparatus has an image receiving sheet conveying section, a latent image forming section, and a developing section arranged close to the latent image forming section. Depending on the model, a latent image is formed at the center of the apparatus main body. A toner image intermediate transfer portion in proximity to the image receiving portion and the image receiving sheet conveying portion.
[0204]
Furthermore, as a method for improving the image quality, an adhesive transfer or heat-assisted transfer system is known instead of or in combination with electrostatic transfer or bias roller transfer. For example, Japanese Patent Laid-Open Nos. 63-113576 and 5-341666 describe specific structures thereof. In particular, a method using a heat-assisted transfer type intermediate transfer belt is preferable when a toner having a small particle diameter is used.
[0205]
According to the image forming method of the present invention, even when an oilless machine without fixing oil is used, the electrophotographic image receiving sheet and the toner can be prevented from being peeled off, or the electrophotographic image receiving sheet and the toner component can be prevented from being offset. In addition, it is possible to realize a good image that has an unprecedented gloss and is rich in photographic feeling.
[0206]
1 and 3 show an example of a belt-fixing type smoothing processing machine. In particular, in the cooling-peeling type belt-type processing machine (endless press) of FIG. 1, the processing unit 1 includes a belt 2, a heating roller 3, , A pressure roller 4, a tension roller 5, a cleaning roller 6, a cooling device 7, and a conveying roller 8.
Inside the belt 2, a belt 2 and a pair of tension rollers 5 are disposed. The belt 2 is stretched in a rotatable manner by a heating roller 3 and a pair of tension rollers 5 arranged at a position away from the heating roller 3. The pressure roller 4 is disposed in contact with the heating roller 3 in contact with the belt 2. The pressure roller 4 and the belt 2 are pressed by the pressure roller 4 and the heating roller 3 to form a nip portion. The cooling device 7 is disposed inside the belt 2 and between the heating roller 3 positioned on the upstream side and the tension roller 5 positioned on the downstream side in the rotation direction of the belt 2. Two conveying rollers 8 are arranged so as to face the cooling device 7 with the belt 2 interposed therebetween. Here, the distance between the two conveying rollers is substantially the same length as the distance between the nip portion and one of the conveying rollers 8 and the distance between the tension roller 5 and the other one of the conveying rollers 8. The cleaning roller 6 is arranged to face the opposite side of the heating roller 3 from the side facing the pressure roller 4 via the belt 2. A pressure is applied between the cleaning roller 6 and the belt 2 by the cleaning roller 6 and the heating roller 3. The heating roller 3, the pressure roller 4, the tension roller 5, the cleaning roller 6, and the transport roller 8 can rotate in conjunction with each other to rotate the belt 2.
[0207]
The belt fixing type smoothing machine shown in FIG. 3 is modified as a belt-like fixing unit of the electrophotographic apparatus shown in FIG. 2 (for example, Fuji Xerox full color laser printer (DCC-500)). Can be used.
In FIG. 2, 100 is an image forming apparatus, 37 is a photosensitive drum, 9 is a developing device, 31 is an intermediate transfer belt, 16 is a recording sheet, and 25 is a belt-like fixing unit. FIG. 3 shows the belt-type fixing unit 25 disposed in the image forming apparatus 100 of FIG.
As shown in FIG. 3, the belt type fixing device 25 includes a heating roll 71, an endless belt 73 rotatably supported by a peeling roll 74 including the heating roll 71, and a tension roll 75, and the heating roll 71. And a pressure roll 72 in pressure contact with the endless belt 73.
A cooling heat sink 77 for forcibly cooling the endless belt 73 is disposed between the heating roll 71 and the peeling roll 74 on the inner surface side of the endless belt 73. 77 constitutes a cooling / sheet conveying section for cooling the electrophotographic image-receiving sheet and conveying the sheet.
[0208]
In the belt-type fixing device 25, as shown in FIG. 3, an electrophotographic transfer sheet having a color toner image transferred and fixed on its surface is transferred to the heating roll 71 and the heating roll 71 via an endless belt 73. A color toner image is introduced into a pressure contact portion (nip portion) with the pressure roll 72 to be pressed so as to be positioned on the heating roll 71 side, and passes through the pressure contact portion between the heating roll 71 and the pressure roll 72. Further, the color toner image T is heated and melted and fixed on the electrophotographic transfer sheet.
[0209]
Thereafter, in the press-contact portion between the heating roll 71 and the pressure roll 72, for example, the toner is heated to a temperature of about 120 to 130 ° C. and melted to fix the color toner image to the image receiving layer. The photographic image-receiving sheet is conveyed together with the endless belt 73 while the image-receiving layer on the surface thereof is in close contact with the surface of the endless belt 73. In the meantime, the endless belt 73 is forcibly cooled by a cooling heat sink 77, and after the color toner image and the image receiving layer are cooled and solidified, the peeling roller 74 uses the waist (rigidity) of the electrophotographic image receiving sheet itself. It is peeled off.
[0210]
The surface of the endless belt 73 after the peeling process is completed is prepared for the next fixing process by removing residual toner and the like by a cleaner (not shown).
[0211]
The method for forming an image on the electrophotographic image-receiving sheet of the present invention is not limited to the above method as long as it is an electrophotographic method using a fixing belt. Any ordinary electrophotographic method can be applied.
For example, a color image can be preferably formed on the electrophotographic image-receiving sheet of the present invention. The color image can be formed using an electrophotographic apparatus capable of forming a full color image. A typical electrophotographic apparatus has an image receiving sheet conveying section, a latent image forming section, and a developing section arranged close to the latent image forming section. Depending on the model, a latent image is formed at the center of the apparatus main body. A toner image intermediate transfer portion in proximity to the image receiving portion and the image receiving sheet conveying portion.
[0212]
Furthermore, as a method for improving the image quality, an adhesive transfer or heat-assisted transfer system is known instead of or in combination with electrostatic transfer or bias roller transfer. For example, Japanese Patent Laid-Open Nos. 63-113576 and 5-341666 describe specific structures thereof. In particular, a method using a heat-assisted transfer type intermediate transfer belt is preferable when a toner having a small particle diameter is used.
[0213]
According to the image forming method of the present invention, even when an oilless machine without fixing oil is used, the electrophotographic image receiving sheet and the toner can be prevented from being peeled off, or the electrophotographic image receiving sheet and the toner component can be prevented from being offset. In addition, it is possible to realize a good image that has an unprecedented gloss and is rich in photographic feeling.
[0214]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to these examples.
In the following examples and comparative examples, “%” and “part” represent “% by mass” and “part by mass”, respectively.
[0215]
(Examples 1-6 and Comparative Examples 1-5)
-Production of support-
Wood pulp made of LBKP (hardwood bleached pulp) was beaten to 300 ml Canadian freeness (CFS) with a double disc refiner. To 100 parts of this pulp material, 1.0 part of cationic starch, 0.5 part of alkyl ketene dimer, 0.5 part of epoxidized fatty acid amide, 0.3 part of polyamine polyamide epichlorohydrin, higher fatty acid ester 0 .03 parts and 0.02 part of colloidal dull silica were added, and the basis weight was 165 / m using a long paper machine.²The thickness of the base paper was 155 to 175 μm using a calendar (density 1.06 to 0.94 g / cm³) Was obtained.
[0216]
The base paper was run at a speed of 150 m / min and subjected to corona discharge treatment on the back surface, and then low density polyethylene (density 0.924 g / cm³  MI = 3 g / 10 min) 10 parts, and high density polyethylene (density 0.966 g / cm)³  MI = 11 g / 10 min) 90 μm layer of 10 μm and low density polyethylene (density 0.922 g / cm³  MI = 5 g / 10 min) 50 parts, and high density polyethylene (density 0.970 g / cm)³  MI = 20 g / 10 min) 15 μm outermost layer consisting of 50 parts was melt-extruded using a coat hanger type two-layer co-extrusion die, and immediately after that, the center line average roughness (Ra ) And a cooling roll having a mat surface whose cooling temperature is appropriately adjusted, and a matte resin layer is provided.
[0217]
Further, after the corona discharge treatment was applied to the surface of the base paper, low density polyethylene (density 0.920 g / cm³  (MI = 5g / 10min) 37.6 parts with TiO₂10 parts masterbatch kneaded 60 parts and 2.4 parts zinc stearate, 4 parts masterbatch kneaded blue pigment, low density polyethylene (density 0.918 g / cm³  14 μm layer consisting of 86 parts of MI = 8 g / 10 min) and low density polyethylene (density 0.920 g / cm³  (MI = 5g / 10min) 37.6 parts with TiO₂A 16 μm maximum consisting of 60 parts and 33 parts of a masterbatch containing 2.4 parts of zinc stearate, 5 parts of a masterbatch containing fluorescent whitening agent, and 4 parts of a masterbatch containing blue pigment. The outer layer was melt-extruded using a coat hanger type two-layer co-extrusion die, and immediately after that, as shown in Table 2, a fine rough surface (fine) whose centerline average roughness (Ra) and cooling temperature were appropriately adjusted A glossy resin layer was provided by molding using a cooling roll having a mat surface.
As described above, Examples 1 to 6 and Comparative Examples 1 to 5 having a glossy resin layer and a matte resin layer on the front and back surfaces of the base paper were obtained.
[0218]
About the matte resin layer (back surface) and glossy resin layer (front surface) of each obtained support, Beck smoothness, centerline average roughness (Ra), and local peak-top average interval (S) were measured by the following methods. . The results are shown in Tables 1 and 2.
[0219]
<Beck smoothness>
Beck smoothness was measured using a Beck smoothness tester manufactured by Kumagai Riki Kogyo Co., Ltd. In addition, it evaluated based on the Beck smoothness test of the paper and paperboard as described in JIS P8119.
[0220]
<Surface roughness>
The center line average roughness (Ra) and the local summit average interval (S) were measured under the following conditions using a universal surface shape measuring machine Surfcoder SE-3C manufactured by Kosaka Laboratory. The definition of the center line average roughness (Ra) and the local peak top average interval (S) is based on the definition and display of the surface roughness in JIS B0601.
Cut-off value (λc) of center line average roughness (Ra) = 0.8 mm, measurement length (Ln) = 4 mm
・ Reference length (L) = 0.08 mm for the average interval between local peaks (S), evaluation length (Ln) = 0.4 mm
[0221]
[Table 1]
Support (back side)

[0222]
[Table 2]
Support (surface)

[0223]
-Formation of back layer-
In the presence of a reactive emulsifier (Adekalia Soap SE-10N, manufactured by Asahi Denka Kogyo Co., Ltd.), 62 parts of styrene as an aromatic ethylenically unsaturated monomer, acrylic acid 8 as an ethylenically unsaturated monomer And 30 parts of 2-ethylhexyl acrylate as the other ethylenically unsaturated monomer were emulsion polymerized to obtain an aqueous dispersion of styrene / acrylic acid ester.
14 parts of an aqueous dispersion of the obtained styrene / acrylic acid ester, 4 parts of a water-soluble polymer compound consisting of a sodium salt of polystyrene sulfonic acid (Chemist SA9, manufactured by Sanyo Chemical Co., Ltd.), 6 parts of colloidal silica, and Methanol 20 parts are mixed and water is added to make the total amount 100 parts on the back surface (matte resin layer) of the support so that the coating thickness after drying is 0.25 μm. The back layer was formed by applying with a wire coater.
[0224]
-Formation of intermediate layer-
On the surface side of the support, the following intermediate layer composition was applied and dried with a wire coater so that the coating thickness after drying was 5 μm.
--Interlayer composition--
・ Water-dispersed acrylic resin ... 100 parts
(Hirose HE-1335 (solid content 45%), manufactured by Hoshi Kogyo Co., Ltd.)
・ Surfactant ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 2 parts
(Nippon Yushi Co., Ltd., Rapisol B-90 (solid content 10%))
・ Ion exchange water ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 30 parts
[0225]
-Formation of toner image-receiving layer-
On the intermediate layer, the following composition for toner image-receiving layer was applied with a wire coater so that the thickness after drying was 7 μm, and dried at 100 ° C. for 5 minutes. Examples 1 to 6 and Comparative Example 1 -5 electrophotographic image-receiving sheets were prepared.
--Toner image-receiving layer composition--
・ Water-dispersed polyester resin: 100 parts
(Unitika Ltd. Elitel KZA-1449 (solid content 30%), flow start temperature (100.4 (° C))
・ Release agent ... 5 parts
(Carnauba wax, manufactured by Chukyo Yushi Co., Ltd., Cerozol 524)
・ White pigment (TiO₂) Aqueous dispersion ... 7.5 parts
[TiO₂(Taipeke R780-2 (manufactured by Ishihara Sangyo)) and aqueous dispersion with polymer dispersant]
・ Surfactant ... 8 parts
(Nippon Yushi Co., Ltd., Rapisol D-337 (solid content 10%))
・ Antistatic agent: 7 parts
(Nippon Yushi Co., Ltd., Rapisol B-90 (solid content 10%))
[0226]
For each of the electrophotographic image-receiving sheets of Examples 1 to 6 and Comparative Examples 1 to 5, the Beck smoothness, centerline average roughness (Ra), and local summit average interval (S) were measured by the same method as described above. In addition, the following methods were used to evaluate image quality (glossiness), back surface roughness, runnability, and adhesion resistance. The results are shown in Tables 3 and 4.
[0227]
<Image quality (glossiness)>
An image forming apparatus (belt and cooling conditions are as follows) in which the fixing unit of the Fuji Xerox full-color laser printer (DCC-500) shown in FIG. 2 is modified to the belt-like fixing unit shown in FIG. Under the B / W conditions, the image was drawn in 10 cm squares in 6 levels (0, 20, 40, 60, 80, 100%). This 6-stage part was measured by 20 degree measurement using a digital variable angle gloss meter (manufactured by Suga Test Instruments, UGV-5D) in accordance with JIS Z 8741, and the minimum value was recorded. The glossiness is preferably 75 or more.
−Belt−
Belt support: polyimide (PI) film, width = 50 cm, thickness = 80 μm
Release layer material for belt: SIFEL 610, which is a fluorocarbon siloxane rubber precursor, was vulcanized and cured to a film thickness of 50 μm.
-Cooling conditions-
Cooler: Heat sink length = 80mm
Speed: 53mm / sec
[0228]
<Roughness on the back>
The roughness of the back surface of each electrophotographic image-receiving sheet obtained was visually observed and evaluated according to the following criteria.
〔Evaluation criteria〕
1: No rough surface on the back
2: There is no problem because there is a feeling of roughness on the back
3: There is a slight backside roughness, which is somewhat problematic
4: Strong roughness on the back surface causes problems
[0229]
<Running>
The total number of sheets in which any of paper feeding failure, jamming, and stacking failure occurred when 100 sheets were continuously fed by the image forming apparatus (same as above) was counted. The traveling property is preferably 2 or less.
[0230]
<Adhesion resistance>
Each of the obtained electrophotographic image-receiving sheets was adjusted at 40 ° C. and 80% RH for 24 hours, and the image-receiving surfaces were overlapped with each other, and a load of 3.5 cm square × 500 g was applied and installed under the same environment for 7 days. Then, the state when pulling the sample apart was evaluated according to the following criteria. The adhesion resistance is preferably 2 or less.
〔Evaluation criteria〕
1: No peeling sound and adhesion marks.
2: There is a slight peeling sound or adhesion mark.
3: The adhesion mark is less than 1/4.
4: 1/4 to less than 1/2 is adhered.
5: 1/2 or more are adhered.
[0231]
[Table 3]
Electrophotographic image-receiving sheet

[0232]
[Table 4]

[0233]
【The invention's effect】
According to the present invention, it is possible to obtain a good image having good glossiness and rich in photographic feeling, and to improve all of prevention of powder falling, surface roughness, running performance, and adhesion resistance. An electrophotographic image-receiving sheet can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a cooling and peeling belt fixing type smoothing processing machine according to the present invention.
FIG. 2 is a schematic diagram illustrating an example of an electrophotographic apparatus used in Examples.
FIG. 3 is a schematic diagram showing an example of a cooling and peeling type belt fixing type smoothing processing machine used in Examples.
[Explanation of symbols]
1 processing section
2 belts
3 Heating roller
4 Pressure roller
5 Tension roller
6 Cleaning roller
7 Cooling device
8 Transport roller
10 Electrophotographic image-receiving sheet
25 Belt type fixing device
71 Heating roll
72 Pressure roll
74 Peeling roll
75 tension roll
73 Endless belt
77 Cooling heat sink
100 Image forming apparatus

Claims (14)

In a support for an electrophotographic image receiving sheet provided with a polyolefin resin layer on both sides of a base paper, the polyolefin resin layer provided on both sides of the base paper has a two-layer structure, and the side on which the toner image receiving layer of the support is provided The Beck smoothness on the surface (back surface) on the side (back surface) of the support is such that the Beck smoothness on the surface (front surface) is 10,000 seconds or more and the centerline average roughness (Ra) is 0.5 μm or less. An electrophotographic image-receiving sheet having a degree of 1500 seconds or less, a center line average roughness (Ra) of 0.5 μm to 20 μm, and a local summit average interval (S) of 20 μm to 100 μm. Support.   The Beck smoothness on the surface (surface) on the side of the support on which the toner image-receiving layer is provided is 15000 seconds or more and the center line average roughness (Ra) is 0.4 μm or less. The Beck smoothness on the surface (back surface) to be provided is 1300 seconds or less, the centerline average roughness (Ra) is 0.75 μm or more and 10 μm or less, and the local peak top average interval (S) is 30 μm or more and 75 μm or less. The support for an electrophotographic image-receiving sheet according to claim 1.   Immediately or immediately after casting the molten polyolefin resin on the surface of the base paper, the surface of the polyolefin resin layer is pressed and cooled with a cooling roll having a fine rough surface (fine mat surface) and melted on the back surface of the base paper. 3. The electron according to claim 1, which is obtained by pressing and cooling with a cooling roll having a rough surface (mat surface) against the surface of the polyolefin resin layer at the same time or immediately after casting the polyolefin resin. Support for photographic image-receiving sheet. The method for producing a support for an electrophotographic image-receiving sheet according to any one of claims 1 to 3 , wherein the surface of the polyolefin resin layer is simultaneously or immediately after casting the molten polyolefin resin on the surface of the base paper. On the other hand, with the cooling roll having a fine rough surface (fine mat surface), the surface of the polyolefin resin layer is roughened simultaneously with or immediately after casting the molten polyolefin resin on the back surface of the base paper ( A method for producing a support for an electrophotographic image-receiving sheet, which is cooled by pressing with a cooling roll having a mat surface.   The method for producing a support for an electrophotographic image-receiving sheet according to claim 4, wherein the surface temperature of the cooling roll is from 0C to 50C.   The method for producing a support for an electrophotographic image-receiving sheet according to any one of claims 4 to 5, wherein the center line average roughness (Ra) of the cooling roll having a rough surface (mat surface) is 0.7 µm or more and 40 µm or less. . In an electrophotographic image-receiving sheet comprising a support and at least one toner image-receiving layer on one surface of the support, and at least one back layer on the other surface of the support,
The support for an electrophotographic image-receiving sheet according to any one of claims 1 to 3 is used as the support, the Beck smoothness on the surface on the toner image-receiving layer side is 10,000 seconds or more, and a center line average The roughness (Ra) is 0.5 μm or less, the Beck smoothness on the back surface on the back layer side is 1500 seconds or less, and the center line average roughness (Ra) is 0.5 μm or more and 20 μm or less. An electrophotographic image-receiving sheet, wherein the peak-to-peak average distance (S) is 20 μm or more and 100 μm or less.   The Beck smoothness on the surface of the toner image receiving layer side is 15000 seconds or more, the centerline average roughness (Ra) is 0.4 μm or less, and the Beck smoothness on the back surface of the back layer side is 1300 seconds or less. The electrophotographic image-receiving sheet according to claim 7, wherein the center line average roughness (Ra) is 0.75 μm or more and 10 μm or less, and the local summit average interval (S) is 30 μm or more and 75 μm or less.   A coating liquid containing a water-dispersed resin is applied to the surface of the support for an electrophotographic image-receiving sheet according to claim 1 to provide a toner image-receiving layer, and water is dispersed on the back surface of the support. The electrophotographic image-receiving sheet according to any one of claims 7 to 8, wherein a back layer is provided by applying a coating solution containing a resin.   The electrophotographic image-receiving sheet according to claim 9, wherein the water-dispersed resin is a soap-free water-dispersible polymer.   The electrophotography according to any one of claims 7 to 10, wherein a cooling and peeling type belt fixing type smoothing processing machine having a heating and pressing means, a cooling means, and a cooling peeling portion is used, and the heating and pressing means is used. An image forming method comprising heating and pressurizing to a temperature equal to or higher than a softening point of a thermoplastic resin in a toner image receiving layer of an image receiving sheet, cooling, and then peeling from a belt member in the heating and pressurizing means.   The image forming method according to claim 11, wherein a layer made of a fluorocarbon siloxane rubber having a uniform thickness is provided on the surface of the fixing belt.   12. The image according to claim 11, wherein the surface of the fixing belt has a silicone rubber layer having a uniform thickness, and the silicone rubber layer has a layer made of a fluorocarbon siloxane rubber having a uniform thickness. Forming method.   The image forming method according to claim 12, wherein the fluorocarbon siloxane rubber has a perfluoroalkyl ether group and / or a perfluoroalkyl group in a main chain.

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