JP3563920B2 - Image forming method - Google Patents

Description

【００８２】
結着樹脂がポリエステル樹脂の場合は、トルエン可溶分のＧＰＣによる分子量分布において、好ましくは分子量３千乃至５万の領域、より好ましくは分子量５千乃至３万の領域に少なくとも１つピークが存在し、分子量１０万以下の成分が好ましくは６０乃至１００重量％、より好ましくは６５乃至９５％となるような結着樹脂が好ましい。
【００８３】
分子量３千乃至５万の領域にピークがなく、分子量３千未満の領域にピークが存在する場合には、高温時における耐ブロッキング性が弱く、現像特性に悪影響を及ぼす。
【００８４】
また、分子量３千乃至５万の領域にピークがなく、分子量５万を超える領域にピークが存在する場合には、低温時における定着性が悪くなる傾向を示す。
【００８５】
分子量１０万以下の成分の含有量が６０重量％未満の場合には、高分子量成分が多いことに起因するＯＨＰ透明性の悪化が見受けられる。
【００８６】
結着樹脂として、スチレン共重合体とポリエステル樹脂を混合して使用することも好ましい。例えば、架橋されたスチレン共重合体と非架橋のポリエステル樹脂との組み合わせ、架橋されたスチレン共重合体と架橋ポリエステル樹脂との組み合わせがトナーの定着性、耐オフセット性、混色性の点で好ましい。
【００８７】
ポリエステル系樹脂は、定着性及び透明性にすぐれ、良好な混色性を必要とするカラートナーに適している。特に、次式
【００８８】
【化１】

（式中、Ｒ_１及びＲ_２はエチレン又はプロピレン基を示し、ｘ及びｙはそれぞれ１以上の整数を示し、かつｘ＋ｙの平均値は２〜１０である。）
で示されるビスフェノール誘導体もしくはその置換体をジオール成分とし、２価以上のカルボン酸またはその酸無水物またはその低級アルキルエステルとからなるカルボン酸成分（例えばフマル酸、マレイン酸、無水マレイン酸、フタル酸、テレフタル酸、イソフタル酸、トリメリット酸、ピロメリット酸など）とを共縮重合した非架橋又は架橋ポリエステル樹脂が好ましい。
【００８９】
さらに、ポリエステル樹脂は、酸価が好ましくは、１乃至３５ｍｇＫＯＨ／ｇ、より好ましくは１乃至２０ｍｇＫＯＨ／ｇ、さらに好ましくは３乃至１５ｍｇＫＯＨ／ｇを有しており、水酸基価が好ましくは２乃至４５ｍｇＫＯＨ／ｇ、より好ましくは３乃至４０ｍｇＫＯＨ／ｇ、さらに好ましくは４乃至３０ｍｇＫＯＨ／ｇを有しているものがトナーの帯電特性の環境安定性の点で好ましい。
【００９０】
ポリエステル樹脂の酸価が１ｍｇＫＯＨ／ｇ未満又は水酸基価が２ｍｇＫＯＨ／ｇ未満の場合には、トナーの帯電付与能が低く、高温高湿環境下において、カブリが多く発生する。また、ポリエステル樹脂の酸価が３５ｍｇＫＯＨ／ｇを超える又は水酸基価が４５ｍｇＫＯＨ／ｇを超える場合には、低温低湿環境下においてチャージアップし、画像濃度低下が著しい。
【００９１】
ポリエステル樹脂の酸価及び水酸基価は、以下の測定方法によって測定される。
【００９２】
〔酸価〕 試料１ｇ中に含有されている遊離脂肪酸、樹脂酸などを中和するのに要する水酸化カリウムのｍｇ数を酸価といい、つぎによって試験を行う。
【００９３】
（１）試薬
（ａ）溶剤エチルエーテル−エチルアルコール混液（１＋１または２＋１）またはベンゼン−エチルアルコール混液（１＋１または２＋１）で、これらの溶液は使用直前にフェノールフタレインを指示薬としてＮ／１０水酸化カリウムエチルアルコール溶液で中和しておく。
【００９４】
（ｂ）フェノールフタレイン溶液 フェノールフタレイン１ｇをエチルアルコール（９５ｖ／ｖ％）１００ｍｌに溶かす。
【００９５】
（ｃ）Ｎ／１０水酸化カリウム−エチルアルコール溶液 水酸化カリウム７．０ｇをできるだけ少量の水に溶かしエチルアルコール（９５ｖ／ｖ％）を加えて１リットルとし、２〜３日放置後ろ過する。標定はＪＩＳ Ｋ ８００６（試薬の含量試験中滴定に関する基本事項）に準じて行う。
【００９６】
（２）操作 試料１〜２０ｇを正しくはかりとり、これに溶剤１００ｍｌおよび指示薬としてフェノールフタレイン溶液数滴を加え、試料が完全に溶けるまで十分に振る。固体試料の場合は水浴上で加温して溶かす。冷却後これをＮ／１０水酸化カリウムエチルアルコール溶液で滴定し、指示薬の微紅色が３０秒間続いたときを中和の終点とする。
【００９７】
（３）計算式 つぎの式によって酸価を算出する。
【００９８】
【数２】

ここにＡ：酸価
Ｂ：Ｎ／１０水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／１０水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）
【００９９】
〔水酸基価〕 試料１ｇを規定の方法によってアセチル化するとき水酸基と結合した酢酸を中和するのに要する水酸化カリウムのｍｇ数を水酸基価といい、つぎの試薬、操作および計算式によって試験を行う。
【０１００】
（１）試薬
（ａ）アセチル化試薬 無水酢酸２５ｇをメスフラスコ１００ｍｌに入れ、ピリジンを加えて全量を１００ｍｌにし、十分に振りまぜる。
【０１０１】
アセチル化試薬は、湿気、炭酸ガスおよび酸の蒸気に触れないようにし、褐色びんに保存する。
【０１０２】
（ｂ）フェノールフタレイン溶液 フェノールフタレイン１ｇをエチルアルコール（９５ｖ／ｖ％）１００ｍｌに溶かす。
【０１０３】
（ｃ）Ｎ／２水酸化カリウム−エチルアルコール溶液 水酸化カリウム３５ｇをできるだけ少量の水に溶かし、エチルアルコール（９５ｖ／ｖ％）を加えて１リットルとし、２〜３日間放置後ろ過する。標定はＪＩＳ Ｋ ８００６によって行う。
【０１０４】
（２）操作 試料０．５〜２．０ｇを丸底フラスコに正しくはかりとり、これにアセチル化試薬５ｍｌを正しく加える。フラスコの口に小さな漏斗をかけ、９５〜１００℃のグリセリン浴中に底部約１ｃｍを浸して加熱する。このときフラスコの首が浴の熱をうけで温度の上がるのを防ぐために、中に丸い穴をあけた厚紙の円盤をフラスコの首の付根にかぶせる。１時間後フラスコを浴から取り出し、放冷後漏斗から水１ｍｌを加えて振り動かして無水酢酸を分解する。さらに分解を完全にするため、再びフラスコをグリセリン浴中で１０分間加熱し、放冷後エチルアルコール５ｍｌで漏斗およびフラスコの壁を洗い、フェノールフタレイン溶液を指示薬としてＮ／２水酸化カリウムエチルアルコール溶液で滴定する。
【０１０５】
なお、本試験と並行して空試験を行う。
【０１０６】
（３）計算式 つぎの式によって水酸基価を算出する。
【０１０７】
【数３】

ここにＡ：水酸基価
Ｂ：空試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
Ｃ：本試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／２水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）
Ｄ：酸価
【０１０８】
本発明において、静電荷像現像用トナーに用いられる低軟化点物質としては、パラフィンワックス、ポリオレフィンワックス、マイクロクリスタリンワックス、フィッシャートロピッシュワックスの如きポリメチレンワックス、アミドワックス、高級脂肪酸、長鎖アルコール、エステルワックス及びこれらのグラフト化合物、ブロック化合物の如き誘導体が挙げられ、これらは低分子量成分が除去されたＤＳＣ吸熱曲線の最大吸熱ピークがシャープなものが好ましい。
【０１０９】
好ましく用いられるワックスとしては、炭素数１５乃至１００個の直鎖状のアルキルアルコール、直鎖状脂肪酸、直鎖状酸アミド、直鎖状エステルあるいは、モンタン系誘導体が挙げられる。これらワックスから液状脂肪酸の如き不純物を予め除去してあるものも好ましい。
【０１１０】
さらに、好ましく用いられるワックスは、アルキレンを高圧下でラジカル重合あるいは低圧下でチーグラー触媒又は、その他の触媒を用いて重合した低分子量のアルキレンポリマー；高分子量のアルキレンポリマーを熱分解して得られるアルキレンポリマー；アルキレンを重合する際に副生する低分子量アルキレンポリマーを分離精製したもの；一酸化炭素及び水素からなる合成ガスからアーゲ法により得られる炭化水素ポリマーの蒸留残分から、あるいは、得られた炭化水素ポリマーの蒸留残分を水素添加して得られる合成炭化水素から、特定の成分を抽出分別したポリメチレンワックスが挙げられる。これらワックスには酸化防止剤が添加されていてもよい。
【０１１１】
本発明に使用される低軟化点物質は、ＤＳＣ吸熱曲線において、好ましくは４０乃至９０℃、さらに好ましくは４５乃至８５℃の温度領域に吸熱メインピークを有することが好ましい。さらに、吸熱メインピークは、半値幅が好ましくは１０℃以内、より好ましくは５℃以内であるシャープメルト性の低軟化点物質が好ましい。特に、低軟化点物質が炭素数１５乃至４５個の長鎖アルキルアルコールと炭素数１５乃至４５個の長鎖アルキルカルボン酸とのエステル化合物を主成分とするエステルワックスが好ましい。
【０１１２】
低軟化点物質のＤＳＣ吸熱曲線において、吸熱メインピークが４０℃未満の温度領域に存在する場合には、トナー粒子の強度が低下し、耐久試験時の現像特性の低下を招きやすい。また、耐ブロッキング性も弱い。
【０１１３】
また、９０℃を超える温度領域に存在する場合には、低温における定着開始点が高くなる。さらに例えば重合法トナーに用いた場合、造粒性が悪化する。
【０１１４】
本発明において、低軟化点物質の吸熱メインピークとしては、ＡＳＴＭ Ｄ３４１８−８に準拠して、ＤＳＣ測定を行い、測定されたＤＳＣ吸熱曲線における最大吸熱ピーク値を用いる。
【０１１５】
本発明において、特に好ましい低軟化点物質は、以下の構成で示されるものである。
【０１１６】
【化２】

〔式中、Ｒ_１及びＲ_２は炭素数１〜４０の有機基を示し、Ｒ_１とＲ_２との炭素数差は３以上であり、ａ及びｂは０〜４の整数を示し、ａ＋ｂは４であり、ｃ及びｄは０〜２５の整数を示し、ｍとｎが同時に０になることはない。〕
【０１１７】
【化３】

〔式中、Ｒ_３及びＲ_４は、炭素数１〜４０の有機基を示し、Ｒ_３とＲ_４との炭素数差は３以上であり、Ｒ_５は水素原子又は炭素数１以上の有機基を示し、ｅ及びｆは０〜３の整数を示し、ｅ＋ｆは１〜３の整数を示し、ｅ＋ｆが２のとき、Ｒ_３とＲ_４のどちらか一方は、炭素数１以上の有機基を示し、ｇ及びｈは０〜２５の整数を示し、ｇとｈが同時に０になることはなく、ｉは１〜３の整数を示し、ｅ＋ｆ＋ｉは４である。〕
【０１１８】
【化４】

〔式中、Ｒ_６及びＲ_８は炭素数６〜３２の有機基を示し、Ｒ_６とＲ_８は同一であり又は異なっており、Ｒ_７は炭素数１〜２０の有機基を示す。〕
【０１１９】
【化５】

〔式中、Ｒ_９及びＲ_１１は炭素数６〜３２の有機基を示し、Ｒ_９とＲ_１１は同一であり又は異なっており、Ｒ_１０は
【０１２０】
【化６】

（式中、ｊ及びｋは１〜１０の整数を示し、ｌは１〜２０の整数を示す。）を示す。〕
【０１２１】
【化７】

〔式中、Ｒ_１１は炭素数１〜４０の有機基を示し、ｍは０〜４の整数を示し、ｎは１〜４の整数を示し、ｍ＋ｎは４であり、ｏ及びｐは０〜２５の整数を示し、ｏとｐが同時に０になることはない。〕
【０１２２】
上記構造式において、有機基としては、具体的には、アルキル基、アシル基、アシルオキシ基、アリール基、アルコキシル基及びアルドケテン基らが挙げられる。
【０１２３】
本発明に用いられる黒色着色剤としてカーボンブラック、磁性体、以下に示すイエロー着色剤、マゼンタ着色剤及びシアン着色剤を用い黒色に調色されたものが利用される。
【０１２４】
イエロー着色剤としては、縮合アゾ化合物、イソインドリノン化合物、アンスラキノン化合物、アゾ金属錯体、メチン化合物、アリルアミド化合物に代表される化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントイエロー１２、１３、１４、１５、１７、６２、７４、８３、９３、９４、９５、９７、１０９、１１０、１１１、１２０、１２７、１２８、１２９、１４７、１６８、１７４、１７６、１８０、１８１、１９１等が好適に用いられる。
【０１２５】
マゼンタ着色剤としては、縮合アゾ化合物、ジケトピロロピロール化合物、アンスラキノン、キナクリドン化合物、塩基染料レーキ化合物、ナフトール化合物、ベンズイミダゾロン化合物、チオインジゴ化合物、ペリレン化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントレッド２、３、５、６、７、２３、４８：２、４８：３、４８：４、５７：１、８１：１、１４４、１４６、１６６、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４が特に好ましい。
【０１２６】
シアン着色剤としては、銅フタロシアニン化合物及びその誘導体、アンスラキノン化合物、塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．ピグメントブルー１、７、１５、１５：１、１５：２、１５：３、１５：４、６０、６２、６６等が特に好適に利用できる。
【０１２７】
これらの黒色着色剤、イエロー着色剤、マゼンタ着色剤及びシアン着色剤は、単独又は混合し更には固溶体の状態で用いることができる。本発明において、着色剤は、色相角、彩度、明度、耐候性、ＯＨＰフイルム上の透明性、トナー粒子中への分散性の点から選択される。本発明において、黒色着色剤としてのカーボンブラック、イエロー着色剤、マゼンタ着色剤及びシアン着色剤のトナーにおける含有量は、結着樹脂１００重量部当り１〜２０重量部が好ましい。
【０１２８】
黒色着色剤として磁性体を用いた場合には、着色剤のトナーにおける含有量は、他の着色剤と異なり、結着樹脂１００重量部当り４０〜１５０重量部が好ましい。
【０１２９】
トナーの摩擦帯電特性を安定化するために使用する荷電制御剤としては、無色でトナーの帯電スピードが速く且つ一定の帯電量を安定して維持できる電荷制御剤が好ましい。更にトナー粒子の製造方法として重合性単量体を含有する単量体組成物を水系媒体中で重合することによりトナー粒子を形成する重合トナー製造方法を用いる場合には、重合阻害性が無く水系媒体中への可溶化物の無い荷電制御剤が特に好ましい。具体的には、ネガ系制御剤としては、サリチル酸、アルキルサリチル酸、ジアルキルサリチル酸、ナフトエ酸、ダイカルボン酸の金属化合物、スルホン酸、カルボン酸を側鎖に持つ高分子型化合物、ホウ素化合物、尿素化合物、ケイ素化合物、カリークスアレーン等が利用でき、また、ポジ系制御剤としては四級アンモニウム塩、該四級アンモニウム塩を側鎖に有する高分子型化合物、グアニジン化合物、イミダゾール化合物等が好ましく用いられる。これらの荷電制御剤のトナーにおける含有量は結着樹脂１００重量部に対し０．５〜１０重量部が好ましい。しかしながら、本発明において荷電制御剤のトナーヘの添加は必須ではなく、二成分現像方法を用いた場合においては、キャリアとの摩擦帯電を利用し、非磁性一成分ブレードコーティング現像方法を用いた場合においては、ブレード部材やスリーブ部材との摩擦帯電を積極的に利用することでトナー粒子中に必ずしも荷電制御剤を含まなくとも良い。
【０１３０】
本発明の静電荷像現像用トナーを製造する方法の１つとしては、結着樹脂、着色剤、低軟化点物質、その他任意成分として荷電制御剤及びその他の内添剤を、加圧ニーダーやエクストルーダー、或いはメディア分散機等を用いて混練して均一に分散せしめた後、機械的又はジェット気流下でターゲットに衝突させて所望のトナー粒径に微粉砕化せしめ、更に分級工程を経て粒度分布をシャープにせしめてトナー粒子を製造する粉砕法によるトナーの製造方法がある。この他に、特公昭３６−１０２３１号公報、特開昭５９−５３８５６号公報、特開昭５９−６１８４２号公報に述べられている単量体組成物を水系媒体中で重合させてトナー粒子を形成する懸濁重合法を用いてトナー粒子を生成する方法や；特開昭６２−１０６４７３号公報や特開昭６３−１８６２５３号公報に開示されている様な、少なくとも１種類以上の微粒子を凝集させ所望の粒径のトナー粒子を得る界面会合法；単量体は可溶で、且つその単量体を重合して生成された重合体は不溶な有機溶剤中で単量体組成物を重合させてトナー粒子を生成する分散重合法；水溶性重合開始剤の存在下で単量体組成物を重合させてトナー粒子を生成する、ソープフリー重合法に代表される乳化重合法によるトナー粒子の製造が挙げられる。
【０１３１】
本発明に用いられるトナー粒子を粉砕方法によって製造する場合には、結着樹脂として高分子量のものと低分子量のものをブレンドして用い、更に必要に応じて低軟化点物質の種類や添加量を変えてトナーの粘弾性特性をコントロールすることが好ましい。特に、結着樹脂として水酸基やカルボキシル基を有するものを使用して混練時に有機金属化合物やその誘導体を加えて金属架橋を起こさせ、ＴＨＦ不溶物を生成することが可能である。本発明に用いられるトナー粒子を重合方法によって製造する場合には、重合性単量体に適当な架橋剤及び／又は樹脂成分を加え、低軟化点物質及び重合開始剤をさらに加えて溶解させて得られる単量体組成物を水系媒体中で造粒し、さらに重合反応を行い、重合された重合体で低軟化点物質をトナー粒子内に内包化し、海−島構造を形成することが好ましい。
【０１３２】
低軟化点物質を結着樹脂で内包化せしめ、海−島構造を構築させる方法としては、水系媒体中で主要単量体よりも低軟化点物質の極性を小さく設定し、更に少量の極性の大きな樹脂又は単量体を添加せしめて重合性単量体を重合させることで、低軟化点物質を結着樹脂で被覆したコア−シェル構造を有するトナー粒子を得る方法が挙げられる。このコア−シェル構造を有するトナー粒子をそのままトナー粒子として用いても良く、或いは極微粒状のトナー粒子を所望の粒径まで凝集させ会合させることで、海−島構造を有するトナー粒子を生成しても良い。これらの方法を用いて海−島構造を構築させる際には、低軟化点物質のうちの少なくとも一種は、融点（ＤＳＣ吸熱曲線における最大吸熱ピーク温度）が重合温度よりも低いことが好ましい。
【０１３３】
低軟化点物質をトナー粒子内に内包化することにより、比較的多量の低軟化点物質をトナー粒子が含有してもトナーの耐ブロッキング性の低下を抑制することができ、また、シャープメルト性の低軟化点物質を使用することにより、機械的衝撃が強いトナー粒子であり、加熱加圧定着時に低温定着性と、良好な混合性を有するトナー粒子を生成し得る。
【０１３４】
本発明において、トナーを重合方法で製造する際に用いられる重合性単量としては、ラジカル重合が可能なビニル系重合性単量体が用いられる。該ビニル系重合性単量体としては、単官能性重合性単量体或いは多官能性重合性単量体を使用することが出来る。単官能性重合性単量体としては、スチレン；α−メチルスチレン、β−メチルスチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、２，４−ジメルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン、ｐ−ｎ−ドデシルスチレン、ｐ−メトキシスチレン、ｐ−フェニルスチレンの如きスチレン誘導体；メチルアクリレート、エチルアクリレート、ｎ−プロピルアクリレート、ｉｓｏ−プロピルアクリレート、ｎ−ブチルアクリレート、ｉｓｏ−ブチルアクリレート、ｔｅｒｔ−ブチルアクリレート、ｎ−アミルアクリレート、ｎ−ヘキシルアクリレート、２−エチルヘキシルアクリレート、ｎ−オクチルアクリレート、ｎ−ノニルアクリレート、シクロヘキシルアクリレート、ベンジルアクリレート、ジメチルフォスフェートエチルアクリレート、ジエチルフォスフェートエチルアクリレート、ジブチルフォスフェートエチルアクリレート、２−ベンゾイルオキシエチルアクリレートの如きアクリル系重合性単量体；メチルメタクリレート、エチルメタクリレート、ｎ−プロピルメタクリレート、ｉｓｏ−プロピルメタクリレート、ｎ−ブチルメタクリレート、ｉｓｏ−ブチルメタクリレート、ｔｅｒｔ−ブチルメタクリレート、ｎ−アミルメタクリレート、ｎ−ヘキシルメタクリレート、２−エチルヘキシルメタクリレート、ｎ−オクチルメタクリレート、ｎ−ノニルメタクリレート、ジエチルフォスフェートエチルメタクリレート、ジブチルフォスフェートエチルメタクリレートの如きメタクリル系重合性単量体；メチレン脂肪族モノカルボン酸エステル；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、安息香酸ビニル、ギ酸ビニルの如きビニルエステル；ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチリエーテルの如きビニルエーテル；ビニルメチルケトン、ビニルヘキシルケトン、ビニルイソプロピルケトンの如きビニルケトンが挙げられる。
【０１３５】
多官能性重合性単量体としては、ジエチレングリコールジアクリレート、トリエチレングリコールジアクリレート、テトラエチレングリコールジアクリレート、ポリエチレングリコールジアクリレート、１，６−ヘキサンジオールジアクリレート、ネオペンチルグリコールジアクリレート、トリプロピレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、２，２’−ビス〔４−（アクリロキシ・ジエトキシ）フェニル〕プロパン、トリメチロールプロパントリアクリレート、テトラメチロールメタンテトラアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレート、ポリエチレングリコールジメタクリレート、１，３−ブチレングリコールジメタクリレリート、１，６−ヘキサンジオールジメタクリレート、ネオペンチルグリコールジメタクリレート、ポリプロピレングリコールジメタクリレート、２，２’−ビス〔４−（メタクリロキシ・ジエトキシ）フェニル〕プロパン、２，２’−ビス〔４−（メタクリロキシ・ポリエトキシ）フェニル〕プロパン、トリメチロールプロパントリメタクリレート、テトラメチロールメタンテトラメタクリレート、ジビニルベンゼン、ジビニルナフタリン、ジビニルエーテル等を挙げられる。
【０１３６】
本発明においては、上述した単官能性重合性単量体を単独或いは、２種以上組み合わせて、又は、上述した単官能性重合性単量体と多官能性重合性単量体を組み合わせて使用する。多官能性重合性単量体は架橋剤として使用することも可能である。
【０１３７】
上述した重合性単量体の重合の際に用いられる重合開始剤としては、油溶性開始剤及び／又は水溶性開始剤が用いられる。例えば、油溶性開始剤としては、２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス−２，４−ジメチルバレロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリルの如きアゾ化合物；アセチルシクロヘキシルスルホニルパーオキサイド、ジイソプロピルパーオキシカーボネート、デカノニルパーオキサイド、ラウロイルパーオキサイド、ステアロイルパーオキサイド、プロピオニルパーオキサイド、アセチルパーオキサイド、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ベンゾイルパーオキサイド、ｔ−ブチルパーオキシイソブチレート、シクロヘキサノンパーオキサイド、メチルエチルケトンパーオキサイド、ジクミルパーオキサイド、ｔ−ブチルヒドロパーオキサイド、ジ−ｔ−ブチルパーオキサイド、クメンヒドロパーオキサイドの如きパーオキサイド系開始剤が挙げられる。
【０１３８】
水溶性開始剤としては、過硫酸アンモニウム、過硫酸カリウム、２，２’−アゾビス（Ｎ，Ｎ’−ジメチレンイソブチロアミジン）塩酸塩、２，２’−アゾビス（２−アミノジノプロパン）塩酸塩、アゾビス（イソブチルアミジン）塩酸塩、２，２’−アゾビスイソブチロニトリルスルホン酸ナトリウム、硫酸第一鉄又は過酸化水素が挙げられる。
【０１３９】
本発明においては、重合性単量体の重合度を制御する為に、連鎖移動剤、重合禁止剤等を更に添加し用いることも可能である。
【０１４０】
本発明においては、トナーの製造方法としては、トナー粒子の形状を均一にコントロールでき、容易にシャープな粒度分布が得られ、且つ３〜８μｍの小粒径のトナー粒子が容易に得られる懸濁重合方法が特に好ましい。さらに一旦得られた重合粒子に更に単量体を吸着せしめた後、重合開始剤を用い重合せしめるシード重合方法も本発明に好適に利用することができる。このとき、吸着せしめる単量体中に、極性を有する化合物を分散あるいは溶解させて使用することも可能である。トナー粒子の製造方法として懸濁重合を利用する場合には、以下の如き製造方法によって単量体組成物から直接的にトナー粒子を製造することが可能である。単量体中にワックスの如き低軟化点物質、着色剤、重合開始剤、架橋剤その他の添加剤を加え、ホモジナイザー、超音波分散機等によって均一に溶解又は分散せしめた単量体組成物を、分散安定剤を含有する水系媒体中に通常の撹拌機またはホモミキサー、ホモジナイザー等により分散せしめる。好ましくは単量体組成物の液滴が所望のトナー粒子のサイズを有するように撹拌速度・時間を調整し、造粒する。その後は分散安定剤の作用により、粒子状態が維持され、且つ粒子の沈降が防止される程度の撹拌を行えば良い。重合温度は４０℃以上、通常５０〜９０℃（好ましくは５５〜８５℃）の温度に設定して重合を行う。重合反応後半に昇温しても良く、更に、トナーの定着時の臭いの原因となる未反応の重合性単量体、副生成物等を除去するために反応後半、又は、反応終了後に一部水系媒体を留去しても良い。反応終了後、生成したトナー粒子を洗浄・ろ過により収集し、乾燥する。
【０１４１】
懸濁重合法においては、通常単量体組成物１００重量部に対して水３００〜３０００重量部を分散媒体として使用するのが好ましい。用いる分散剤として例えば無機系酸化物として、リン酸三カルシウム、リン酸マグネシウム、リン酸アルミニウム、リン酸亜鉛、炭酸カルシウム、炭酸マグネシウム、水酸化カルシウム、水酸化マグネシウム、水酸化アルミニウム、メタケイ酸カルシウム、硫酸カルシウム、硫酸バリウム、ベントナイト、シリカ、アルミナ等が挙げられる。有機系化合物としては例えばポリビニルアルコール、ゼラチン、メチルセルロース、メチルヒドロキシプロピルセルロース、エチルセルロース、カルボキシメチルセルロースのナトリウム塩、デンプン等が使用される。これら分散剤は、重合性単量体１００重量部に対して０．２〜２．０重量部を使用することが好ましい。
【０１４２】
これら分散剤は、市販のものをそのまま用いても良いが、細かい均一な粒度を有する分散粒子を得るために、分散媒体中にて高速撹拌下にて無機系酸化物を生成させることも出来る。例えば、リン酸三カルシウムの場合、高速撹拌下において、リン酸ナトリウム水溶液と塩化カルシウム水溶液を混合することで懸濁重合方法に好ましい分散剤を得ることが出来る。これらの分散剤の微細化のため０．００１〜０．１重量％の界面活性剤を併用しても良い。具体的には市販のノニオン、アニオン、カチオン型の界面活性剤が利用できる。例えばドデシル硫酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、オレイン酸ナトリウム、ラウリル酸ナトリウム、ステアリン酸カリウム、オレイン酸カルシウム等が好ましく用いられる。
【０１４３】
本発明のトナーとしては、形状係数ＳＦ−１の値が１００〜１６０、より好ましくは１００〜１５０、さらに好ましくは１００〜１２５のトナーが好ましい。
【０１４４】
本発明において、形状係数を示すＳＦ−１とは、例えば日立製作所製ＦＥ−ＳＥＭ（Ｓ−８００）を用い倍率５００倍に拡大したトナー像を１００個無作為にサンプリングし、その画像情報はインターフェースを介して例えばニコレ社製画像解析装置（ＬｕｚｅｘＩＩＩ）に導入し解析を行い、下式より算出し得られた値を形状係数ＳＦ−１と定義する。
【０１４５】
【数４】

〔式中、ＭＸＬＮＧはトナー粒子の絶対最大長を示し、ＡＲＥＡはトナー粒子の投影面積を示す。〕
【０１４６】
形状係数ＳＦ−１は、トナー粒子の丸さの度合いを示す。トナーの形状係数ＳＦ−１が１６０より大きいトナーは、球形から徐々に不定形に近づき、それにつれて転写効率の低下が認められる。
【０１４７】
本発明のトナーには、テフロン粉末、ステアリン酸亜鉛粉末、ポリフッ化ビニリデン粉末の如き滑剤粉末；酸化セリウム、炭化硅素、ケイ酸ストロンチウム、チタン酸カルシウム、チタン酸ストロンチウムの如き研磨剤；シリカ、酸化チタン、酸化アルミニウムの如き流動性向上剤：ケーキング防止剤：カーボンブラック、酸化亜鉛、酸化錫の如き導電性付与剤等を外添することが好ましい。
【０１４８】
特に、無機微粉体としては、シリカ微粉体、酸化チタン微粉体、酸化アルミニウム微粉体、ケイ酸ストロンチウム微粉体、チタン酸カルシウム微粉体、チタン酸ストロンチウム微粉体の如き無機微粉体が好ましい。該無機微粉体は、シランカップリング剤、シリコーンオイル、又はそれらの混合物の如き疎水化剤で疎水化されていることが好ましい。外添剤は、通常トナー粒子１００重量部に対して０．１〜５重量部使用するのが良い。
【０１４９】
次に本発明に用いられるラミネートシートの一例を図１を用いて説明する。
【０１５０】
図１において、Ａは、耐熱性樹脂を主成分とするベースシートを示し、Ｂは、熱可塑性樹脂を主成分とする表面コート層を示す。尚、本発明において主成分とは、全構成成分を基準として、５０重量％以上含まれている成分を指す。
【０１５１】
ベースシートＡは、熱定着または熱圧定着時の加熱によって著しい熱変形を起こさない程度の耐熱性を有する必要がある。本発明で用いられるベースシートＡとしては、その熱変形温度が、ＡＳＴＭ Ｄ６８４に記載されている４．６ｋｇ／ｃｍ^２の測定条件で、好ましくは１４５℃以上、より好ましくは１５０℃以上であるものが好ましい。本発明で用いられるベースシートＡは、より具体的には、上記の測定条件で１４５℃以上の熱変形温度を有し、且つ最高使用温度が１００℃以上の耐熱性を有する樹脂、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリエステル、ポリアミドまたはポリイミドが挙げられる。これらの中でも、ポリエチレンテレフタレートが耐熱性及び透明性の点で特に好ましい。
【０１５２】
上記の様な材料からなるベースシートＡの厚さは、画像定着時の加熱によってフィルムが柔らかくなった時にもシワが発生しない程度の厚みが必要であり、例えば、ポリエチレンテレフタレートの場合には５０μｍ以上あればよい。また、光透過性のフィルムであっても厚みが増大すると透光率が低下する為、ベースシートＡの厚さは、好ましくは５０〜３００μｍ、より好ましくは７０〜２００μｍ、更に好ましくは１００〜１５０μｍ程度のものを用いるのが好ましい。
【０１５３】
本発明に用いられるラミネートシートでは、上記の様なベースシートＡ上に、熱可塑性樹脂を主成分とするコート層Ｂが形成されている。本発明において、コート層Ｂを形成する方法としては、有機溶剤に溶解したコート層Ｂの形成材料からなる塗工液を、バーコート法、ディップ法、スプレー法、及びスピンコート法等の塗工方法で光透過性のベースシートＡの表面に塗布し、常温或いは加熱して乾燥する方法が挙げられる。更に、ベース層である耐熱性樹脂Ａとコート層Ｂとの密着性を改良する目的で、プラズマ処理、コロナ放電処理の如き表面処理を行うことや、耐熱性樹脂層Ａとコート層Ｂとの間に易接着層を形成することも好ましい。
【０１５４】
ここで、易接着層として用いることのできる樹脂としては、例えば、ポリエステル樹脂、アクリル酸エステル樹脂、メタクリル酸エステル樹脂、スチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体等の樹脂が挙げられる。
【０１５５】
次に、本発明のラミネートシートのコート層Ｂの構成材料について詳述する。先ず、本発明において使用される熱可塑性樹脂について説明する。コート層Ｂの形成材料である熱可塑性樹脂は、例えば、従来公知のポリエステル系樹脂、ポリメチルメタクリレート系樹脂、アクリル系樹脂、スチレン系樹脂、スチレン−アクリル系樹脂、ゴム系樹脂、エポキシ系樹脂、塩化ビニル系、酢酸ビニル系樹脂、ポリウレタン系樹脂等の種々の熱可塑性樹脂、及びそれらに架橋剤を使用したものが挙げられる。
【０１５６】
本発明においては、数平均分子量が３千〜５０万、より好ましくは５千〜２０万の範囲内にある熱可塑性樹脂が好適に用いられる。即ち、３千より小さいと定着手段の表面に対するラミネートシートの貼り付きが顕著になり、５０万よりも大きいと、加熱定着時におけるコート層Ｂの軟化性が不足し、トナー粒子をコート層に埋没させてトナーの粒状性を減少させる効果が損なわれて画像性が低下し、更に、コート層Ｂの形成の際に用いられる塗工液が高粘度となる為、塗工液の塗工性が低下して加工性に劣るため好ましくない。
【０１５７】
本発明においては、熱可塑性樹脂の数平均分子量をＧＰＣの測定による分子量分布から求めた。また、ＧＰＣ測定は、ＧＰＣ−１５０Ｃ（ウォーターズ社製）により次の条件で測定した。即ち、４０℃のヒートチャンバー中でカラムを安定化させ、この温度におけるカラムに溶媒としてＴＨＦ（テトラヒドロフラン）を毎分１ｍｌの流速で流し、試料濃度として０．０５〜０．６重量％に調製した樹脂のＴＨＦ試料溶液を５０〜２００μｌ注入して測定する。そして、試料の有する分子量分布を、数種の単分散ポリスチレン標準試料により作成された検量線の対数値とカウント数との関係から求め、分子量を算出する。検量線作成用の標準ポリスチレン試料としては、市販の東ソー製の標準ポリスチレンを用い、分子量が６×１０^２、２．１×１０^３、４×１０^３、１．７５×１０^４、５．１×１０^４、１．１×１０^５、３．９×１０^５、８．６×１０^５、２×１０^６、４．４８×１０^６のものを使用した。検出器はＲＩ（屈折率）検出器を用い、カラムは東ソー製のＴＳＫｇｅｌ Ｇ１０００Ｈ、Ｇ２０００Ｈ、Ｇ３０００Ｈの組合せを使用した。
【０１５８】
また、上記の様な構成材料からなるコート層Ｂの厚さは、定着されるべきトナーの粒径によって最適な厚みが変わるが、好ましくは２〜５０μｍ、より好ましくは２〜３０μｍ、さらに好ましくは３〜３０μｍ、さらに一層好ましくは３〜１５μｍとするのが良い。尚、コート層Ｂの最適な厚みは、透光性や画像ボケ等によっても制限されるが、コート層には屈曲性があるので、例え厚くなっても画像のひび割れを生じる心配はない。
【０１５９】
本発明に用いられるラミネートシートは、表面コート層Ｂ中に帯電防止剤を混合させるか又は帯電防止剤を塗布して、表面抵抗率をトナーの転写に適した領域である１０^７〜１３^１３Ωに調整するのが好ましい。
【０１６０】
本発明において、表面抵抗率はＪＩＳ Ｋ ６９１１に準拠して測定し、実際にはアドバンテスト社製のＲ８３４０Ａ及びＲ１２７０２Ａを用い、温度２０℃，湿度６０％ＲＨ，電圧１００Ｖで測定した。尚、表面抵抗率の単位は、体積抵抗率（Ωｃｍ）との混同を避けるために慣例として「Ω／□」が用いられているが、本発明においては、ＪＩＳ Ｋ ６９１１に基づき「Ω」を用いる。
【０１６１】
この際に使用する帯電防止剤は、従来公知のものをいずれも使用することができるが、例えば、四級アンモニウム塩系化合物、ピリジニウム塩系化合物、ホスホニウム塩系化合物、アルキルベタイン系化合物、アルキルイミダゾリン系化合物、アルキルアラニン系化合物、ポリオキシエチレン型非イオン系化合物、多価アルコール型非イオン系化合物、ポリビニルベンジル型カチオンやポリアクリル酸型カチオン等の導電性樹脂、ＳｎＯ_２やＳｎＯ_２−Ｓｂ等の金属酸化物超微粒子をバインダー樹脂中に分散したもの等が挙げられる。これらの帯電防止剤は、表面コート層形成時の塗布溶液中に混合して同時に塗布するか、表面コート層形成後、上記の帯電防止剤をアルコール等に溶解した溶液を塗布して、帯電防止層を形成するのが好ましい。帯電防止層を形成する位置としては、表面コート層Ｂの上に設けてもよいし、べースシートＡと表面コート層Ｂとの間に設けてもよい。
【０１６２】
上記の様な構成材料からなる本発明に用いられるラミネートシートは、透明性に優れることが要求され、光透過性が、ＯＨＰシートとしての全光線透過率が少なくとも８０％以上、好ましくは８５％以上であり、且つヘイズが少なくとも１０以下、好ましくは７以下、更に好ましくは３以下であることが好ましい。
【０１６３】
尚、本発明における透明性の測定は、ＪＩＳ Ｋ−７１０５に準拠して行った。
【０１６４】
本発明の画像形成方法は、カラー複写機、カラープリンター、カラーファックス等、前述したトナーを使用する電子写真方式全てに応用が可能である。また、本発明の画像形成方法は、オイルの如き離型性を定着手段に塗布しない定着手段に好ましく適用することが出来るが、従来の粉砕法により調製されたトナーを使用し、オイルの如き離型剤を別途塗布する従来の定着手段を使用する電子写真方式にも応用可能である。
【０１６５】
以下、本発明の画像形成方法を実施し得る画像形成装置を図６及び図７を用いて詳細に説明する。
【０１６６】
図６に示されるカラー電子写真装置は、装置本体の右側から装置本体の略中央部にわたって設けられている転写材搬送系Ｉと、装置本体の略中央部に、上記転写材搬送系Ｉを構成している転写ドラム６１５に近接して設けられている潜像形成部ＩＩと、上記潜像形成部ＩＩと近接して配設されている現像手段（すなわち回転式現像装置）ＩＩＩとに大別される。
【０１６７】
上記転写材搬送系Ｉは、以下の様な構成となっている。上記装置本体の右壁（図６右側）に開口部が形成されており、該開口部に着脱自在な転写材供給用トレイ６０２及び６０３が一部機外に突出して配設されている。該トレイ６０２及び６０３の略直上部には給紙用ローラ６０４及び６０５が配設され、これら給紙用ローラ６０４及び６０５と左方に配された矢印Ａ方向に回転自在な転写ドラム６０５と連係するように、給紙用ローラ６０６及び給紙ガイド６０７及び６０８が設けられている。上記転写ドラム６１５の外周面近傍には回転方向上流側から上流側に向かって当接用ローラ６０９、グリッパ６１０、転写材分離用帯電器６１１、分離爪６１２が順次配設されている。
【０１６８】
上記転写ドラム６１５の内周側には転写帯電器及び転写材分離用帯電器が配設されている。転写ドラム６１５の転写材が巻き付く部分にはポリ弗化ビニリデンの如き、ポリマーで形成されている転写シート（図示せず）が貼り付けられており、転写材は該転写シート上に静電的に密着貼り付けされている。上記転写ドラム６１５の右側上部には上記分離爪６１２と近接して搬送ベルト手段６１６が配設され、該搬送ベルト手段６１６の転写材搬送方向終端（右側）には定着装置６１８が配設されている。該定着装置６１８よりもさらに搬送方向後流には装置本体６０１の外へと延在し、装置本体６０１に対して着脱自在な排出用トレイ６１７が配設されている。
【０１６９】
次に上記潜像形成部ＩＩの構成を説明する。図６矢印方向に回転自在な潜像担持体である感光ドラム（例えば、ＯＰＣ感光ドラム）６１９が、外周面を上記転写ドラム６１５の外周面と当接して配設されている。上記感光ドラム６１９の上方でその外周面近傍には、該感光ドラム６１９の回転方向上流側から下流側に向かって除電用帯電器６２０、クリーニング手段６２１及び一次帯電器６２３が順次配設され、さらに上記感光ドラム６１９の外周面上に静電潜像を形成するためのレーザービームスキャナのごとき像露光手段６２４、及びミラーのごとき像露光反射手段６２５が配設されている。
【０１７０】
上記回転式現像装置ＩＩＩの構成は以下のごとくである。上記感光ドラム６１９の外周面と対向する位置に、回転自在な筐体（以下「回転体」という）６２６が配設され、該回転体６２６中には四種類の現像装置が周方向の四位置に搭載され、上記感光ドラム６１９の外周面上に形成された静電潜像を可視化（すなわち現像）するようになっている。上記四種類の現像装置は、それぞれイエロー現像装置６２７Ｙ、マゼンタ現像装置６２７Ｍ、シアン現像装置６２７Ｃ及びブラック現像装置６２７ＢＫを有する。
【０１７１】
上記したごとき構成の画像形成装置全体のシーケンスについて、フルカラーモードの場合を例として説明する。上述した感光ドラム６１９が図６矢印方向に回転すると、該感光ドラム６１９は一次帯電器６２３によって帯電される。図６の装置においては、感光ドラム６１９の周速（以下、プロセススピードとする）は１００ｍｍ／ｓｅｃ以上（例えば、１３０〜２５０ｍｍ／ｓｅｃ）である。一次帯電器６２３による感光ドラム６１９に対する帯電が行われると、原稿６２８のイエロー画像信号にて変調されたレーザー光Ｅにより画像露光が行われ、感光ドラム６１９上に静電潜像が形成され、回転体６２６の回転によりあらかじめ現像位置に定置されたイエロー現像装置６２７Ｙによって上記静電潜像の現像が行われ、イエロートナー画像が形成される。
【０１７２】
給紙ガイド６０７、給紙ローラ６０６、給紙ガイド６０８を経由して搬送されてきた転写材は、所定のタイミングにてグリッパ６１０により保持され、当接用ローラ６０９と該当接用ローラ６０９と対向している電極とによって静電的に転写ドラム６１５に巻き付けられる。転写ドラム６１５は、感光ドラム６１９と同期して図６矢印方向に回転しており、イエロー現像装置６２７Ｙにより形成されたイエロートナー画像は、上記感光ドラム６１９の外周面と上記転写ドラム６１５の外周面とが当接している部位にて転写帯電器６１３によって転写材上に転写される。転写ドラム６１５はそのまま回転を継続し、次の色（図６においてはマゼンタ）の転写に備える。
【０１７３】
感光ドラム６１９は、上記除電用帯電器６２０により除電され、クリーニングブレードによるクリーニング手段６２１によってクリーニングされた後、再び一次帯電器６２３によって帯電され、次のマゼンタ画像信号により画像露光が行われ、静電潜像が形成される。上記回転式現像装置は、感光ドラム６１９上にマゼンタ画像信号による像露光により静電潜像が形成される間に回転して、マゼンタ現像装置６２７Ｍを上述した所定の現像位置に配置せしめ、所定のマゼンタトナーにより現像を行う。引き続いて、上述したごときプロセスをそれぞれシアン色及びブラック色に対しても実施し、四色のトナー像の転写が終了すると、転写材上に形成された三色顕画像は各帯電器６２２及び６１４により除電され、上記グリッパ６１０による転写材の把持が解除されると共に、該転写材は、分離爪６１２によって転写ドラム６１５より分離され、搬送ベルト６１６で定着装置６１８に送られ、熱と圧力により定着され一連のフルカラープリントシーケンスが終了し、所要のフルカラープリント画像が転写材の一方の面に形成される。
【０１７４】
次に、図７を参照しながら、他の画像形成方法をより具体的に説明する。
【０１７５】
図７に示す装置システムにおいて、現像器７４−１、７４−２、７４−３、７４−４に、それぞれシアントナーを有する現像剤、マゼンタトナーを有する現像剤、イエロートナーを有する現像剤及びブラックトナーを有する現像剤が導入され、磁気ブラシ現像方式又は非磁性一成分現像方式等によって感光体７１に形成された静電荷像を現像し、各色トナー像が感光体７１上に形成される。感光体７１はＳｅ、Ｃｄｓ、ＺｎＯ_２、ＯＰＣ、ａ−Ｓｉの様な光導電絶縁物質層を持つ感光ドラムもしくは感光ベルトである。感光体７１は図示しない駆動装置によって矢印方向に回転される。
【０１７６】
感光体７１としては、アモルファスシリコン感光層、又は有機系感光層を有する感光体が好ましく用いられる。
【０１７７】
有機感光層としては、感光層が電荷発生物質及び電荷輸送性能を有する物質を同一層に含有する単一層型でもよく、又は電荷輸送層を電荷発生層を成分とする機能分離型感光層であっても良い。導電性基体上に電荷発生層、次いで電荷輸送層の順で積層されている構造の積層型感光層は好ましい例の一つである。
【０１７８】
有機感光層の結着樹脂はポリカーボネート樹脂、ポリエステル樹脂、アクリル系樹脂が特に、転写性、クリーニング性が良く、クリーニング不良、感光体へのトナーの融着、外添剤のフィルミングが起こりにくい。
【０１７９】
帯電工程では、コロナ帯電器を用いる感光体７１とは非接触である方式と、ローラ等を用いる接触型の方式があり、いずれのものも用いられる。効率的な均一帯電、シンプル化、低オゾン発生化のために図７に示す如く接触方式のものが好ましく用いられる。
【０１８０】
帯電ローラ７２は、中心の芯金７２ｂとその外周を形成した導電性弾性層７２ａとを基本構成とするものである。帯電ローラ７２は、感光体７１面に押圧力をもって圧接され、感光体７１の回転に伴い従動回転する。
【０１８１】
帯電ローラを用いた時の好ましいプロセス条件としては、ローラの当接圧が５〜５００ｇ／ｃｍで、直流電圧に交流電圧を重畳したものを用いた時には、交流電圧＝０．５〜５ｋＶｐｐ、交流周波数＝５０Ｈｚ〜５ｋＨｚ、直流電圧＝±０．２〜±１．５ｋＶであり、直流電圧を用いた時には、直流電圧＝±０．２〜±５ｋＶである。
【０１８２】
この他の帯電手段としては、帯電ブレードを用いる方法や、導電性ブラシを用いる方法がある。これらの接触帯電手段は、高電圧が不必要になったり、オゾンの発生が低減するといった効果がある。
【０１８３】
接触帯電手段としての帯電ローラ及び帯電ブレードの材質としては、導電性ゴムが好ましく、その表面に離型性被膜を設けても良い。離型性被膜としては、ナイロン系樹脂、ＰＶＤＦ（ポリフッ化ビニリデン）、ＰＶＤＣ（ポリ塩化ビニリデン）などが適用可能である。
【０１８４】
感光体上のトナー像は、電圧（例えば、±０．１〜±５ｋＶ）が印加されている中間転写体７５に転写される。転写後の感光体表面は、クリーニングブレード７８を有するクリーニング手段７９でクリーニングされる。
【０１８５】
中間転写体７５は、パイプ状の導電性芯金７５ｂと、その外周面に形成した中抵抗の弾性体層７５ａからなる。芯金７５ｂは、プラスチックのパイプに導電性メッキをほどこしたものでも良い。
【０１８６】
中抵抗の弾性体層７５ａは、シリコーンゴム、テフロンゴム、クロロプレンゴム、ウレタンゴム、ＥＰＤＭ（エチレンプロピレンジエンの３元共重合体）などの弾性材料に、カーボンブラック、酸化亜鉛、酸化スズ、炭化ケイ素の如き導電性付与材を配合分散して電気抵抗値（体積抵抗率）を１０^５〜１０^１１Ω・ｃｍの中抵抗に調整した、ソリッドあるいは発砲肉質の層である。
【０１８７】
中間転写体７５は感光体７１に対して並行に軸受けさせて感光体７１の下面部に接触させて配設してあり、感光体７１と同じ周速度で矢印の反時計方向に回転する。
【０１８８】
感光体７１の面に形成担持された第１色のトナー像が、感光体７１と中間転写体７５とが接する転写ニップ部を通過する過程で中間転写体７５に対する印加転写バイアスで転写ニップ城に形成された電界によって、中間転写体７５の外面に対して順次に中間転写されていく。
【０１８９】
必要により、着脱自在なクリーニング手段８０により、転写材へのトナー像の転写後に、中間転写体７５の表面がクリーニングされる。中間転写体上にトナー像がある場合、トナー像を乱さないようにクリーニング手段８０は、中間転写体表面から離される。
【０１９０】
中間転写体７５に対して並行に軸受けさせて中間転写体７５の下面部に接触させて転写手段が配設され、転写手段７７は例えば転写ローラ又は転写ベルトであり、中間転写体７５と同じ周速度で矢印の時計方向に回転する。転写手段７７は直接中間転写体７５と接触するように配設されていても良く、またベルト等が中間転写体７５と転写手段７７との間に接触するように配置されても良い。
【０１９１】
転写ローラの場合、中心の芯金７７ｂとその外周を形成した導電性弾性層７７ａとを基本構成とするものである。
【０１９２】
中間転写体及び転写ローラとしては、一般的な材料を用いることが可能である。中間転写体の弾性層の体積固有抵抗値よりも転写ローラの弾性層の体積固有抵抗値をより小さく設定することで転写ローラヘの印加電圧が軽減でき、転写材上に良好なトナー像を形成できると共に転写材の中間転写体への巻き付きを防止することができる。特に中間転写体の弾性層の体積固有抵抗値が転写ローラの弾性層の体積固有抵抗値より１０倍以上であることが特に好ましい。
【０１９３】
中間転写体及び転写ローラの硬度は、ＪＩＳ Ｋ−６３０１に準拠し測定される。本発明に用いられる中間転写体は、１０〜４０度の範囲に属する弾性層から構成されることが好ましく、一方、転写ローラの弾性層の硬度は、中間転写体の弾性層の硬度より硬く４１〜８０度の値を有するものが中間転写体への転写材の巻き付きを防止する上で好ましい。中間転写体と転写ローラの硬度が逆になると、転写ローラ側に凹部が形成され、中間転写体への転写材の巻き付きが発生しやすい。
【０１９４】
転写手段７７は中間転写体７５と等速度或は周速度に差をつけて回転させる。転写材７６は中間転写体７５と転写手段７７との間に搬送されると同時に、転写手段７７にトナーが有する摩擦電荷と逆極性のバイアスを転写バイアス手段から印加することによって中間転写体７５上のトナー像が転写材７６の表面側に転写される。
【０１９５】
転写用回転体の材質としては、帯電ローラと同様のものも用いることができ、好ましい転写のプロセス条件としては、ローラの当接圧が５〜５００ｇ／ｃｍで、直流電圧が±０．２〜±１０ｋＶである。
【０１９６】
例えば、転写ローラの導電性弾性層７７ｂはカーボン等の導電材を分散させたポリウレタン、エチレン−プロピレン−ジエン系三元共重合体（ＥＰＤＭ）等の体積抵抗１０^６〜１０^１０Ωｃｍ程度の弾性体でつくられている。芯金７７ａには定電圧電源によりバイアスが印加されている。バイアス条件としては、±０．２〜±１０ｋＶが好ましい。
【０１９７】
次いで転写材７６は、ハロゲンヒータ等の発熱体を内蔵させた加熱ローラとこれと押圧力をもって圧接された弾性体の加圧ローラとを基本構成とする定着器８１へ搬送され、加熱ローラと加圧ローラ間と通過することによってトナー像が転写材に加熱加圧定着される。フィルムを介してヒータにより定着する方法を用いても良い。
【０１９８】
上記の図６及び図７に示す画像形成装置でラミネートシートに、トナーにより形成されたトナー画像は、図２及び図３に示す加熱定着手段によってラミネートシートに加熱定着されラミネートシートに画像が形成される。
【０１９９】
図２は、本発明に用いられる加熱加圧定着装置の一例を示す概略図である。図２中、１は定着ローラー２及び加圧ローラー３を有する加熱加圧定着手段である。定着ローラー２と加圧ローラー３とは互いに所定の圧力を持って圧接されており、未定着のトナー画像６を有する被記録材５は、この定着ローラー２と加圧ローラー３との間を通過することによって、被記録材５に熱及び圧力が付与されて未定着のトナー画像６は被記録材５上に定着され、この結果、トナー画像７が形成される。尚、定着ローラー２には、ハロゲンヒータの如き加熱手段４が内部に設けられている。
【０２００】
定着ローラー２の表面は、四フッ化エチレン樹脂（ＰＴＦＥ）、ペルフルオロアルコキシフッ素樹脂（ＰＦＡ）又はフッ化エチレン−プロピレン共重合体（ＦＥＰ）の如きフッ素系樹脂によって構成されている。
【０２０１】
一方、フィルム加熱方式の加熱加圧装置は、他の加熱加圧装置として知られている熱ローラー方式・熱板方式・ベルト加熱加圧方式・フラッシュ加熱方式・オープン加熱方式等の加熱装置ないしは画像加熱定着装置との対比において、下記挙げる利点があり効果的なものである。
【０２０２】
（１）フィルム加熱方式の加熱加圧定着装置では、加熱体として、低熱容量の線状加熱体をフィルム状の薄膜とした低熱容量のものを用いることができる為、省電力化・ウエイトタイム短縮化（クイックスタート性）が可能になり、また、本機内の昇温を迎えることも出来る。
【０２０３】
（２）フィルム加熱方式の加熱加圧定着装置にあっては、定着点と分離点とを別に設定できるため、オフセットを有効に防止することが出来る。その他、他の方式装置の種々の欠点を解決できる。
【０２０４】
図３に、上記の様な特徴を有するフィルム加熱方式の加熱加圧定着装置（画像加熱定着装置）の概略図を示した。
【０２０５】
図３中、２０３は支持体に固定支持された加熱体（セラミックヒータ）であるが、この加熱体２０３に耐熱性フィルム（定着フィルム）２０１を加圧回転体として加圧ローラー２０２で密着させて摺動搬送させる。そして、耐熱性フィルム２０１を挟んで加熱体２０３と加圧ローラー２０２とで形成される圧接ニップ部（定着ニップ部）Ｎの耐熱性フィルム２０１と加圧ローラー２０２との間に、被加熱材としての画像を定着すべき被記録材Ｐを導入し、耐熱性フィルム２０１と共に圧接ニップ部Ｎを狭持されながら搬送させることによって、加熱体２０３の熱を耐熱性フィルム２０１を介して被記録材Ｐの表面に付与して、被記録材Ｐ上の未定着顕画像（トナー画像）Ｔを被記録材Ｐ面に加熱定着させる。圧接ニップ部Ｎを通過した被記録材Ｐは、フィルム２０１の面から分離されて、図の左方ヘと搬送される。耐熱性フィルム２０１に当接されている２０４はフェルト状のパッドであり、図３に示した装置では、該パッド２０４により耐熱性フィルム２０１に別途オイルが供給されている。
【０２０６】
本発明においては、上記の様な構成を有する加熱加圧定着装置においては、別途シリコーンオイルの如き離型剤を供給しないことが、定着後の被記録材のベタツキ防止の点で好ましい。しかし、定着後の被記録材のベタツキが問題にならない程度の量の離型剤であれば、定着手段と、被記録材上にある未定着のトナー画像との間の定着部に離型剤を供給しながら加熱加圧定着することも可能である。離型剤の供給は、具体的には、図２に示した加圧定着装置では定着ローラー２の表面に図示しないオイルパッドの如き塗布部材で、図３に示した加熱加圧定着装置では２０４で示したオイルパッドの如き塗布部材に、夫々シリコーンオイルの如き離型剤を含浸させることによって行われる。また、この定着部に別途供給する離型剤の量としては、被記録材上に塗布される離型剤の塗布量が、好ましく０．０４ｍｇ／枚（Ａ４サイズ）以下、より好ましくは０．０２ｍｇ／枚（Ａ４サイズ）以下となるような量であることが好ましい。
【０２０７】
【実施例】
以下に本発明の実施例を示すが、本発明はなんらこれらに限定されるものではない。
【０２０８】
＜実施例１＞
（シアントナーＮｏ．１の製造）
高速撹拌装置ＴＫ−ホモミキサーを備えた２リットル用四つ口フラスコ中に、イオン交換水７１０重量部と０．１モルｌ／Ｎａ₃ＰＯ₄水溶液４４５重量部を添加し回転数を１２０００回転に調整し、７０℃に加温せしめた。ここに１．０モル／リットル−ＣａＣｌ₂水溶液６８重量部を徐々に添加し微小な難水溶性分散剤Ｃａ₃（ＰＯ₄）₂を含む分散媒系を調製した。
・スチレン単量体 １６３重量部
・２エチルヘキシルアクリレート ２１重量部
・ｎ−ブチルアクリレート単量体 １６重量部
・Ｃ．Ｉ．ピグメントブルー１５：３ １４重量部
・線状ポリエステル １０重量部
（フタール酸−プロピレンオキサイド変性ビスフェノールＡ）
・ジアルキルサルチル酸金属化合物 ２重量部
・ジビニルベンゼン ０．５重量部
・炭素数２２のアルキルカルボン酸と炭素数２２のアルキルアルコールとのエステル化合
物を主成分とするエステル化合物 ３０重量部
【０２０９】
上記混合物をアトライターを用い３時間分散させた後、重合開始剤であるラウリルパーオキサイド３．０重量部を添加した分散物を、上記で調製した分散媒中に投入し１２０００ｒｐｍで１０分間造粒した。その後高速撹拌器からプロペラ撹拌羽根に撹拌器を変え、６０ｒｐｍで重合を１０時間継続させた。重合終了後スラリーを冷却し、希塩酸を添加し分散剤を除去せしめた。
【０２１０】
更に洗浄、乾燥を行ない、重量平均径が６．４μｍであるシアントナー粒子を得た。上記シアン粒子１００重量部と疎水性シリカ１．５重量部をヘンシェルミキサーで混合し、シアントナーＮｏ．１を得た。
【０２１１】
得られたシアントナーＮｏ．１の粘弾性特性（貯蔵弾性率Ｇ’、損失弾性率Ｇ”及びｔａｎ（δ））のグラフを図４に示し、かつ各温度における貯蔵弾性率Ｇ’の値を表１に示す。
【０２１２】
（ラミネートシートＮｏ．１の製造）
１００μｍ厚のＰＥＴからなる透明基体上に、熱可塑性樹脂として水系ポリエステルエマルジョン（数平均分子量：１９５００、Ｔｇ：４０℃）９０部と、離型剤として水系マイクロクリスタリンワックスエマルジョン（融点：９０℃）１０部とをポリエステルエマルジョンの粘度が８０ｃｐｓの条件下で混合して得た液を塗工液として、バーコード法によって塗布し、１００℃で１０分間乾燥して乾燥厚みが１５μｍの塗膜を得、表面層を形成した。更に、その上の表面に、ＰＱ−５０Ｂ（総研化学製）及びイソプロピルアルコールからなる固形分濃度約２％の塗工液を塗布・乾燥して、表面抵抗率を約１．２×１０^１０Ω（２０℃，６０％ＲＨ）に調整して、ラミネートシートＮｏ．１シート１を得た。
【０２１３】
（画像形成及び評価）
シアントナーＮｏ．１及びラミネートシートＮｏ．１を、市販のフルカラー複写機（ＣＬＣ５００：キヤノン社製）改造機に用いて、温度２３℃，湿度６５％ＲＨの環境下で、現像コントラスト３２０Ｖにて現像してトナー画像を形成し、得られたトナー画像をラミネートシート上に転写し、階調を有する未定着トナー画像を得た。ラミネートシート上に形成された未定着トナー画像（トナーの乗り量０〜０．４ｍｇ／ｃｍ^２）を、図２に示すローラーの表面がフッ素系樹脂である外部定着器（オイル塗布機能なし；ローラー径４０φ）にて、定着温度１８０℃，プロセススピード４０ｍｍ／ｓｅｃで、加熱加圧定着を行ない定着画像（イメージングシート）を得た。
【０２１４】
得られた定着画像の中間調部分の透過率及びヘイズ（雲価）を測定した。
【０２１５】
透過率の測定は、島津自己分光光度計ＵＶ２２００（島津製作所社製）を使用し測定した。そして、ラミネートシート単独の透過率を１００％とし、
マゼンタトナーの場合：６５０ｎｍ
シアントナーの場合 ：５００ｎｍ
イエロートナーの場合：６００ｎｍ
での最大吸収波長における透過率を測定し以下の評価基準に基づいて評価した。
【０２１６】
（透過率の評価基準）
◎：透過率が８０％以上
○：透過率が７０％以上８０％未満
△：透過率が６０％以上７０％未満
×：透過率が６０％未満
【０２１７】
ヘイズの測定は、ヘイズメーターＮＤＨ−３００Ａ（日本発色工業社製）を用いて測定し、ラミネートシート単独のヘイズとの差を測定し、以下の評価基準に基づいて評価した。
【０２１８】
（ヘイズの評価基準）
◎：ヘイズが２０％未満
○：ヘイズが２０％以上２５％未満
△：ヘイズが２５％以上３５％未満
×：ヘイズが３５％以上
【０２１９】
さらに、上記測定方法において、ハーフトーン部とベタ部各々の初期及び耐久５０００枚後の画像の透過率及びヘイズの変化差について評価した。
【０２２０】
（初期画像の透過率と耐久５０００枚後の画像の透過率との差の評価基準）
◎：８％未満
○：８％以上１２％未満
△：１２％以上１８％未満
×：１８％以上
（初期画像のヘイズと耐久５０００枚後の画像のヘイズとの差の評価基準）
◎：８％未満
○：８％以上１２％未満
△：１２％以上１８％未満
×：１８％以上
【０２２１】
さらにラミネートシートの搬送性について以下の通り評価を行った。
【０２２２】
シアントナーＮｏ．１及びラミネートシートＮｏ．１を市販のフルカラー複写機（ＣＬＣ５００；キヤノン社製）改造機に用いて、温度２３℃，湿度６５％ＲＨの環境下で、現像コントラスト３２０Ｖにて現像してトナー画像を形成し、得られたトナー画像をラミネートシート上に転写し、画像面積比率５％の未定着トナー画像を得た。ラミネートシート上に形成された未定着画像を図２に示す。定着ローラーの表面がフッ素系樹脂である外部定着器（オイル塗布機能なし；ローラー径４０φ）にて、定着温度１８０℃、プロセススピード４０ｍｍ／ｓｅｃで、加熱加圧定着を行った。このときの加熱定着装置である外部定着器におけるラミネートシートの搬送性について以下の評価基準に基づいて評価した。
【０２２３】
（搬送性の評価基準）
○：ラミネートシートが定着ローラーに巻付くことなく通過した。
△：ラミネートシートの最初の部分が定着ローラーにわずかに巻付きぎみだが、約１０ｇｆの圧力で、ローラーヘ押し付けた分離爪の使用で問題なく通過した。
×：約１０ｋｆの圧力で、ローラーへ押し付けた分離爪の使用によっても、ラミネートシートが定着ローラーに巻付いた。
【０２２４】
＜実施例２＞
着色剤として、イエロー着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ１７）を使用することを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すイエロートナーＮｏ．１を製造した。実施例１で用いたシアントナーＮｏ．１に代えてイエロートナーＮｏ．１を用いて実施例１と同様にして画像形成及び評価を行なった。評価結果を表２に示す。
【０２２５】
＜実施例３＞
着色剤として、マゼンタ着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｒｅｄｌ２２）を使用することを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すマゼンタトナーＮｏ．１を製造した。実施例ｌで用いたシアントナーＮｏ．１に代えてマゼンタトナーＮｏ．１を用いて実施例ｌと同様にして画像形成及び評価を行なった。評価結果を表２に示す。
【０２２６】
＜実施例４＞
着色剤として、ブラック着色剤（カーボンブラック）を使用することを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして、表５に示すブラックトナーＮｏ．１を製造した。
【０２２７】
実施例１で用いたシアントナーＮｏ．１、実施例２で用いたイエロートナーＮｏ．１、実施例３で用いたマゼンタトナーＮｏ．１及び上記で得られたブラックトナーＮｏ．１の４種のトナーを実施例１で用いた市販のフルカラー複写機（ＣＬＣ５００；キヤノン社製）改造機に用いて、フルカラーモードにて実施例１と同一の現像条件でラミネートシート上にフルカラートナー画像を形成し、得られたフルカラートナー画像をラミネートシート上に転写し、画像濃度５％の未定着フルカラートナー画像を得た。ラミネートシート上に形成された未定着のフルカラートナー画像を実施例ｌと同様に図２に示す外部定着器にて、実施例１と同様にして加熱加圧定着を行ったところ、耐久前後においてもシート搬送性ならびに混色性に優れたベタツキ感のない画像が入手できた。
【０２２８】
耐久による混色性を示すものとして、以下の方法を用いた。まず、分光放射輝度計ＰＲ６５０（フォトリサーチ社製）測定によるトナー乗り量０〜０．４ｍｇ／ｃｍ^２の未定着画像の定着ＯＨＰの投影画像の色空間を求める。次に実施例の初期投影画像の色空間（ａ^＊，ｂ^＊）の面積を１００とし、実施例の耐久投影画像の色空間面積、比較例の初期、耐久投影画像の色空問を求める。評価結果を表６に示す。
【０２２９】
なお、１００は、混色性が良好であることを示し、数字が低下するごとに混色性が悪化することを示す。
【０２３０】
＜実施例５＞
架橋剤としてのジビニルベンゼンの使用量を１．０重量部とすることを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すシアントナーＮｏ．２を製造した。実施例ｌで用いたシアントナーＮｏ．ｌに代えてシアントナーＮｏ．２を用いて実施例１と同様にして画像形成及び評価を行った。
【０２３１】
＜実施例６＞
実施例１のシアントナーＮｏ．１の製造で用いたエステル化合物を炭素数１８のアルキルジカルボン酸と炭素数１８のアルキルアルコールとのジエステル化合物を主成分とするエステル化合物に代えることを除いて実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すシアントナーＮｏ．３を調製した。実施例１で用いたシアントナーＮｏ．１に代えてシアントナーＮｏ．３を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２３２】
＜実施例７＞
離型剤をステアリン酸アミドエマルジョン（融点；１００℃）に代えた以外はラミネートシートＮｏ．１と同様の調製を行ない、ラミネートシートＮｏ．２を得た。
【０２３３】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートシートＮｏ．２を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２３４】
＜実施例８＞
熱可塑性樹脂をポリエステルエマルジョン（数平均分子量：１６５００、Ｔｇ：１６℃）に代えた以外は、ラミネートシートＮｏ．１と同様の調製を行ない、ラミネートシートＮｏ．３を得た。
【０２３５】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートシートＮｏ．３を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２３６】
＜実施例９＞
１００μｍ厚のＰＥＴからなる透明基体上に、熱可塑性樹脂としてポリエステル（数平均分子量：２２０００、Ｔｇ：４５℃）２０部と、離型剤としてラノリンワックス（融点：６４℃）５部、トルエン６０部、ＭＥＫ１５部とからなる混合液を塗工液として、バーコード法によって塗布し、１００℃で１０分間乾燥して乾燥厚みが１５μｍの塗膜を得、トナー受容層を形成した。更に、その上の表面に、ＰＱ−５０Ｂ（総研化学製）及びイソプロピルアルコールからなる固形分濃度約２％の塗工液を塗布・乾燥して、表面抵抗率を約１．２×１０^１０Ω（２０℃，６０％ＲＨ）に調整して、ラミネートシート４を得た。
【０２３７】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートＮｏ．４を用い、実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２３８】
＜実施例１０＞
エステル化合物の使用量を７重量部とすることを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すシアントナーＮｏ．４を製造した。実施例１で用いたシアントナーＮｏ．１に代えてシアントナーＮｏ．４を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２３９】
＜実施例１１＞
エステル化合物の使用量を８５重量部とすることを除いては、実施例１のシアントナーＮｏ．１の製造と同様にして表１に示すシアントナーＮｏ．５を製造した。実施例１で用いたシアントナーＮｏ．１に代えてシアントナーＮｏ．５を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表２に示す。
【０２４０】
＜比較例１＞
実施例１のシアントナーＮｏ．１の製造において、エステル化合物をパラフィン系低軟化点物質に代え、かつ、架橋剤であるジビニルベンゼンを使用しないことを除いては、シアントナーＮｏ．１の製造と同様にして表３に示すシアントナーＮｏ．６を製造した。得られたシアントナーＮｏ．６の粘弾性特性（貯蔵弾性率Ｇ’、損失弾性率Ｇ”及びｔａｎ（δ））のグラフを図５に示し、かつ各温度における貯蔵弾性率Ｇ’の値を表３に示す。
【０２４１】
実施例１で用いたシアントナーＮｏ．１に代えてシアントナーＮｏ．６を用いて、実施例１と同様にして画像形成及び評価を行った。評価結果を表４に示す。
【０２４２】
＜比較例２＞
実施例１のシアントナーＮｏ．１の製造において、エステル化合物をパラフィン系低軟化点物質に代えることを除いて実施例１と同様にして表３に示すシアントナーＮｏ．７を製造した。実施例１で用いたシアントナーＮｏ．１に代えてシアントナーＮｏ．７を用いて、実施例１と同様にして画像形成及び評価を行った。評価結果を表４に示す。
【０２４３】
＜比較例３＞
離型剤をポリエチレンワックスエマルジョン（融点１２４℃）に代えた以外は、ラミネートシートＮｏ．１と同様にして、ラミネートシートＮｏ．５を得た。
【０２４４】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートシートＮｏ．５を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表４に示す。
【０２４５】
＜比較例４＞
離型剤をポリエステルエマルジョン（数平均分子量：５１０００，Ｔｇ：７０℃）に代えた以外は、ラミネートシートＮｏ．１と同様にして、ラミネートシートＮｏ．６を得た。
【０２４６】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートシートＮｏ．６を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表４に示す。
【０２４７】
＜比較例５＞
熱可塑性樹脂をポリエステルエマルジョン（数平均分子量：２００００，Ｔｇ：−２０℃）に代えた以外は、ラミネートシートＮｏ．１と同様にして、ラミネートシートＮｏ．７を得た。
【０２４８】
実施例１で用いたラミネートシートＮｏ．１に代えてラミネートシートＮｏ．７を用いて実施例１と同様にして画像形成及び評価を行った。評価結果を表４に示す。
【０２４９】
＜比較例６＞
着色剤として、イエロー着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ１７）を使用することを除いては、比較例１のシアントナーＮｏ．６の製造と同様にして表３に示すイエロートナーＮｏ．２を製造した。
【０２５０】
実施例１で用いたシアントナーＮｏ．１に代えてイエロートナーＮｏ．２を用いて実施例１と同様にして画像形成及び評価を行なった。評価結果を表４に示す。
【０２５１】
＜比較例７＞
着色剤として、マゼンタ着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｒｅｄ１２２）を使用することを除いては、比較例１と同様にする。このときのマゼンタトナーをＮｏ．２とし、物性を表３に示す。また評価結果を表４に示す。
【０２５２】
＜比較例８＞
着色剤として、ブラック着色剤（カーボンブラック）を使用すること以外は、比較例１と同様にし、表５に示すブラックトナーＮｏ．２を製造する。
【０２５３】
シアントナーとしてＮｏ．６、イエロートナーとしてＮｏ．２、マゼンタトナーとしてＮｏ．２、ブラックトナーとしてＮｏ．２を用いることを除いて実施例４と同様にして、画像形成及び評価を行なった。評価結果を表６に示す。
【０２５４】
＜比較例９＞
着色剤として、イエロー着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ１７）を使用することを除いては、比較例２のシアントナーＮｏ．７の製造と同様にして表３に示すイエロートナーＮｏ．３を製造した。
【０２５５】
実施例１で用いたシアントナーＮｏ．１に代えてイエロートナーＮｏ．３を用いて、実施例１と同様にして画像形成及び評価を行なった。評価結果を表４に示す。
【０２５６】
＜比較例１０＞
着色剤として、マゼンタ着色剤（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｒｅｄ１２２）を使用すること以外は、比較例２と同様にする。このときのマゼンタトナーをＮｏ．３とし、物性は表３に示す。また評価結果を表４に示す。
【０２５７】
＜比較例１１＞
着色剤として、ブラック着色剤（カーボンブラック）を使用すること以外は、比較例２と同様にし、表５に示すブラックトナーＮｏ．３を製造する。
【０２５８】
シアントナーとしてＮｏ．７、イエロートナーとしてＮｏ．３、マゼンタトナーとしてＮｏ．３、ブラックトナーとしてＮｏ．３を用いることを除いて実施例４と同様にして、画像形成及び評価を行なった。評価結果を表６に示す。
【０２５９】
＜比較例１２＞
ラミネートシートを、ラミネートシートＮｏ．５に代えること以外は、実施例４と同様にして、画像形成及び評価を行った。評価結果を表６に示す。
【０２６０】
【表１】

【０２６１】
【表２】

【０２６２】
【表３】

【０２６３】
【表４】

【０２６４】
【表５】

【０２６５】
【表６】

【０２６６】
【発明の効果】
本発明によれば、ＯＨＰにより投影されたカラー画像が中間調部分においても初期及び耐久にて、くすむことなく、良好な色調再現性を有するカラー画像を多数枚耐久後まで形成することができる。
【図面の簡単な説明】
【図１】本発明に用いられる積層（ラミネート）シートの構成を表わす断面図を示す。
【図２】本発明の加熱加圧方法に使用可能な加熱加圧定着手段を示す。
【図３】本発明の加熱加圧方法に使用可能な別の構成の加熱加圧定着手段を示す。
【図４】本発明のトナーの貯蔵弾性率、損失弾性率及びｔａｎ（δ）の曲線を示す。
【図５】比較例トナーの貯蔵弾性率、損失弾性率及びｔａｎ（δ）の曲線を示す。
【図６】本発明の画像形成方法を実施し得る画像形成装置の概略説明図を示す。
【図７】本発明の画像形成方法を実施し得る他の画像形成装置の概略説明図を示す。
【符号の説明】
１ 加熱定着手段
２ 定着ローラー
３ 加圧ローラー
４ 加熱手段
５ 被記録材（ラミネートシート）
６ 未定着トナー画像
７ 定着されたトナー画像
Ａ 基材層（ベースフィルム）
Ｂ トナー受容層
Ｐ 被記録材（ラミネートシート）
Ｔ トナー
２０１ 耐熱性フィルム
２０２ 加圧ローラー
２０３ 加熱体
２０４ オイルパッド[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming method for heating and fixing a toner image formed on a recording material with toner, and forming a toner image on the recording material.
[0002]
[Prior art]
Conventionally, in a general full-color image forming method, a photosensitive drum of a photosensitive drum is uniformly charged, and an image is exposed to laser light modulated by a magenta image signal of a document to form an electrostatic latent image on the photosensitive drum. The electrostatic latent image is developed by a magenta developing device, a magenta toner image layer is formed on a photosensitive drum, and the magenta toner developed on the photosensitive drum is transferred to a recording material conveyed by a transfer charger. Transfer to the top to form a magenta image.
[0003]
Next, the photosensitive drum after the development and transfer described above is neutralized by a static eliminator, cleaned, and then charged again by a primary charger. The image formation and the transfer of the cyan toner image onto the recording material to which the magenta toner image has been transferred are performed. Transfer onto recording material. Further, the recording material on which the four color toner images are formed is fixed by the action of heat and pressure by a fixing unit such as a fixing roller to form a full-color image.
[0004]
In recent years, such image forming apparatuses have begun to be used not only in office work copying machines for copying original manuscripts in general, but also in printers as computer output devices or personal copy for individuals. I have. In addition to the field represented by such a laser beam printer, the development of a plain paper fax using a basic engine is also rapidly developing.
[0005]
Therefore, in the image forming apparatus as described above, smaller and lighter, further higher speed, higher image quality, and higher reliability have been pursued, and the machine is configured by variously simpler elements in various points. It is becoming. As a result, the performance required of the toner has become higher, and if the performance of the toner is not improved, a better machine cannot be realized.
[0006]
In recent years, along with various copying needs, demand for color copying has rapidly increased, and even higher image quality and higher resolution are desired in order to more faithfully copy original color images. From these viewpoints, the toner used in the color image forming method needs to have good melting property and color mixing property when heat is applied, and has a low softening point and a low melting temperature and a sharp melt property. High toner is required. By using such a toner having a high sharp-melt property, the color reproduction range of a copy can be widened, and a color copy faithful to a document image can be obtained.
[0007]
However, such a color toner having a high sharp melt property generally has a high affinity with a fixing roller, and tends to be easily offset to the fixing roller. In particular, in the case of a fixing unit in a color image forming apparatus, since a magenta toner, a cyan toner, a yellow toner, and a black toner are formed on a recording material, a plurality of toner layers are formed. Tends to occur.
[0008]
Conventionally, in order to improve the releasability of the toner from the fixing roller, for example, the surface of the fixing roller is formed of a material having excellent releasability from the toner (for example, a silicone rubber or a fluorine-based resin). In order to prevent the offset and prevent the roller surface from being fatigued, the surface is coated with a thin film of a liquid having a high releasability such as silicone oil or fluorine oil. Although this method is extremely effective in preventing toner offset, it requires a device for supplying an anti-offset liquid, complicates the fixing device, and the applied oil constitutes a fixing roller. This causes separation between the layers, which results in a problem of shortening the life of the fixing roller.
[0009]
With recent various needs for copying, various types of paper, coated paper, and plastic films are used as recording materials. Above all, attention has been paid to the necessity of a light-transmitting sheet (OHP sheet) for using an overhead projector (OHP) for presentation. In particular, the OHP sheet, unlike paper, has a low oil absorbing ability, so that the oil used in the above fixing device adheres to the surface of the recording material. As a result, the OHP sheet after image formation is coated with oil. Inevitably, the stickiness is inevitable, and the image quality is degraded. Further, there is a possibility that a releasable oil such as silicone oil evaporates due to heat and contaminates the inside of the machine, and further, a problem such as a treatment of recovered oil may occur.
[0010]
Therefore, there are great expectations for establishing a fixing system that does not require oil application at the time of fixing an image, which solves the above-mentioned problems, and for developing a new toner for achieving the fixing.
[0011]
To solve the above problem, a toner containing a release agent such as wax is disclosed in JP-A-61-273554. In a toner containing wax, the heat conductivity in the toner is improved by the wax that melts at a low temperature, and as a result, low-temperature fixing is possible. More preferably, since the wax melted at the time of fixing also functions as a release agent, high-temperature offset can be prevented without applying a release agent such as oil to the fixing roller.
[0012]
When a color toner image or a full-color toner image is formed on a light-transmitting sheet using an electrophotographic method having a dry developing method, and these images are projected using an OHP device, a full-color image on the light-transmitting sheet is obtained. Despite exhibiting sufficient color-developing properties, the projected image shows a grayish color tone as a whole, and the phenomenon that the color tone reproduction range becomes extremely narrow occurs. This phenomenon is due to the fact that the unfixed toner image formed on the smooth light-transmitting sheet does not flow sufficiently due to heating at the time of fixing and retains the granularity, so that the incident light is scattered at the time of projection and it is projected on the screen. The result of shading is the result. In particular, in the intermediate tone portion or the highlight portion where the image density is low, the phenomenon that the color tone to be reproduced becomes gray because the absorption by the dye or pigment in the toner decreases due to the decrease in the number of toner particles. .
[0013]
On the other hand, when a toner image formed on a recording material such as plain paper is visually observed, since a reflected image of light applied to the fixed toner image is visually observed, a slight Even if the graininess remains, the effect on the image quality is small. However, when observing or projecting a toner image on a screen with transmitted light, as in an OHP device, if the residual shape due to the toner particles is clear, light transmission deteriorates due to light scattering and the color tone becomes gray. It will be disgusting. Therefore, the recording material used in the OHP apparatus is required to have an effect of reducing the granularity of the toner after fixing the color image and improving the light transmission.
[0014]
For this reason, conventionally, as a recording material for electrophotography, a light-transmitting recording material in which a surface layer made of a thermoplastic resin such as styrene-acrylic resin or polyester resin is provided on a transparent base sheet is used for fixing toner. Various proposals have been made from the viewpoints of improving sharpness by improving the properties, and improving transportability and blocking resistance. For example, JP-A-1-263085, JP-A-6-19180, JP-A-6-19485 and JP-A-6-332221 are mentioned. Further, as a means for reducing the granularity of the toner after fixing and improving the light transmittance, as described in JP-A-2-263462 and JP-A-7-199515, A method of burying in a surface layer by heat and pressure during fixing is used. These light-transmitting recording materials improve the granularity of the toner after fixing due to the effect of the resin constituting the surface layer, so that the light-transmitting properties are improved and the projecting property in an OHP apparatus is excellent. At this time, if a resin which is not sufficiently plasticized by heat and pressure at the time of fixing is used for the surface layer, penetration of the toner particles into the receptor layer becomes extremely small, and the projected image shows a gray color tone.
[0015]
Further, based on the background described above, a releasing system such as a wax is contained in the toner, and a fixing system is formed without applying a releasing agent such as an oil. When the coating layer of the recording material is made of soft resin, the following adverse effects may occur. The disadvantage is that when an unfixed image having a small image area ratio such as a halftone portion is fixed, the action of a release agent such as wax contained in the toner is insufficient, and the thermoplastic resin is mainly used. Is applied to the fixing roller. Therefore, it is desired to improve an image forming method for obtaining a higher quality projected image.
[0016]
Furthermore, in recent years, a demand for high reliability, for example, a long service life is also an indispensable item, and even if each member is somewhat worn, it is necessary to provide an image which is not different from the initial image.
[0017]
[Problems to be solved by the invention]
An object of the present invention is to provide an image forming method which solves the above problems.
[0018]
That is, an object of the present invention is to provide a color image having good color tone reproducibility when used in an overhead projector (OHP) so that a projected color image is not grayed even in a halftone portion having a low image density. Another object of the present invention is to provide a method for forming an image of an imaging sheet that becomes a full-color image.
[0019]
Further, an object of the present invention is to fix a toner image formed by a toner containing a release agent such as wax when fixing a toner image, without using an oil coating or with a very small amount of coating. Accordingly, an object of the present invention is to provide an image forming method of an imaging sheet which does not stick to a fixing roller, even if it is a halftone portion having a low image density.
[0020]
Furthermore, an object of the present invention is to provide a method for forming an imaging sheet that is a color image or a full-color image having good color tone reproducibility without dulling even in durability, especially in a halftone portion where the image density is low. It is in.
[0021]
Still another object of the present invention is to provide a method for forming an imaging sheet of a full-color image without stickiness by heating and pressing means with no oil supplied or an application amount of 0.04 mg / sheet (A4) or less. It is in.
[0022]
It is a further object of the present invention to provide a method of forming a color or full-color image imaging sheet having excellent transparency and good quality.
[0023]
[Means for Solving the Problems]
The above invention is achieved by the following invention.
[0024]
That is, a method for forming an imaging sheet image for forming a fixed image of a toner image formed by toner on a laminated sheet having at least a base sheet and a surface coat layer containing a thermoplastic resin as a main component,
The toner comprises a binder resin, a colorant andEster wax containing ester compound as main componentAnd the ratio (G′60 / G′80) of the storage elastic modulus (G′60) at a temperature of 60 ° C. to the storage elastic modulus (G′80) at a temperature of 80 ° C. is 80 or more, and a temperature of 155 The ratio (G'155 / G'190) of the storage elastic modulus (G'155) at 190 ° C to the storage elastic modulus (G'190) at 190 ° C is 0.95 to 5.0.,
TheThe surface coat layer contains a low softening point substance having a melting point of 40 ° C to 120 ° C.The surface coat layer has a polyester resin, and the surface resistivity of the surface coat layer is 10 ⁷ ~ 13 ¹³ IsAnd an image forming method.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
The inventor heats and fixes a toner image formed by toner on a laminated (laminated) sheet having at least a base sheet and a surface coat layer mainly composed of a thermoplastic resin, and forms an image on the laminated sheet. In the image forming method, the results of diligent studies on the transparency of the imaging sheet on which an image was formed on the laminate sheet and the projected image characteristics due to OHP, (1) controlling the storage elastic modulus at each temperature of the toner, By dispersing a low softening point substance having a certain range of melting point in the surface coat layer forming the laminate, when used for OHP, the projected color image is not dull even in the initial stage and is durable. Imaging of high-quality color images or full-color images with high spatial transparency and high transparency It was found to be able to form the over door.
[0026]
The imaging sheet is fixed while being given sufficient heat and pressure from the fixing roller and the pressure roller at a low speed. At this time, in the melted toner binder molecules, the low softening point substance in the toner receiving layer of the imaging sheet is immersed in a molten state, and a plastic effect occurs, and the sharper melt property of the toner binder is promoted. Improves the smoothing of the imaging sheet image. This greatly affected the projected image of the halftone portion (halftone portion) having a small toner image area ratio regardless of the initial and endurance. In other words, by matching the viscoelasticity of the toner with the inclusion of a low softening point substance in the toner receiving layer constituting the imaging sheet, a projected image having a wider color space (particularly, a halftone portion) can be obtained. High chroma and high brightness were obtained.
[0027]
Further, it has been found that an imaging sheet having no oil application function or having little sticking to a fixing roller can be formed even in a halftone portion having a low image density.
[0028]
Regarding the viscoelasticity of the toner, there are JP-A-1-128071, JP-A-4-353866, JP-A-6-5904, etc., but they are not satisfactory.
[0029]
The toner used in the present invention has a ratio (G'60 / G'80) of the storage elastic modulus (G'60) at a temperature of 60 ° C to the storage elastic modulus (G'80) at a temperature of 80 ° C of preferably 80 or more. Is preferably 100 to 400, more preferably 150 to 300. Further, the ratio (G'155 / G'190) of the storage elastic modulus (G'155) at a temperature of 155 ° C to the storage elastic modulus (G'190) at a temperature of 190 ° C is 0.95 to 5.0, preferably It is good to be 1.0 to 5.0, more preferably 1.1 to 4.8.
[0030]
The ratio (G'60 / G'80) of the storage elastic modulus (G'60) at a temperature of 60 [deg.] C. to the storage elastic modulus (G'80) at a temperature of 80 [deg.] C. is hardly deformed even when an external force is applied. 4 shows the storage elastic properties of a binder resin in a process of shifting from a glassy state or a glass transition state to a deformable state. When the ratio (G'60 / G'80) is 80 or more, it means that the viscoelasticity of the toner rapidly decreases during the process of heating from a temperature of 60 ° C. to a temperature of 80 ° C. Thereby, low-temperature fixing can be performed favorably in the heating and pressing fixing step.
[0031]
Therefore, the toner layer formed on the laminate sheet is easily melted and deformed quickly at the time of fixing, the surface property of the fixed image is smoothed, and the color mixing between the color toners is improved.
[0032]
When the ratio (G′60 / G′80) of the storage elastic modulus (G′60) at a temperature of 60 ° C. to the storage elastic modulus (G′80) at a temperature of 80 ° C. is less than 80, the temperature is 60 ° C. In the process of heating to a temperature of 80 ° C., no sharp viscoelastic properties of the toner are observed, the surface smoothness of the fixed image is impaired, and the color mixing between the color toners is hindered. Transparency and color reproducibility become difficult.
[0033]
In the present invention, the storage elastic modulus (G′60) at a temperature of 60 ° C. of the toner is preferably 1 × 10⁸~ 1 × 10¹⁰dyn / cm², More preferably 2 × 10⁸~ 9 × 10⁹dyn / cm², More preferably 2.5 × 10⁸~ 7 × 10⁹Good to be.
[0034]
The storage elastic modulus (G′60) at a temperature of 60 ° C. of the toner is 1 × 10⁸dyn / cm²If it is less than 1, the pressure and the rubbing force in the developing device are weak, adversely affect the durable developing property, and 1 × 10¹⁰dyn / cm²When the ratio exceeds the above range, it is difficult to obtain a sharp melt toner, and the OHP transparency is not good.
[0035]
In the present invention, the storage elastic modulus (G'80) at a temperature of 80 ° C. of the toner is preferably 1 × 10⁵~ 1 × 10⁷dyn / cm², More preferably 2 × 10⁵~ 9 × 10⁶dyn / cm², More preferably 3 × 10⁵~ 8 × 10⁶dyn / cm²Good to be.
[0036]
The storage elastic modulus (G'80) at a temperature of 80 ° C. of the toner is 1 × 10⁵dyn / cm²If it is less than 1, the heat resistance is weak, the blocking resistance is reduced, and 1 × 10⁷dyn / cm²When the ratio exceeds, the image smoothness after fixing cannot be obtained, and the OHP transparency is not good.
[0037]
The ratio (G′155 / G′190) of the storage elastic modulus (G′155) at a temperature of 155 ° C. of the toner to the storage elasticity (G′190) at a temperature of 190 ° C. is 0.95 to 5.0. As a result, an appropriate elasticity term can be obtained in the toner, the influence of the deterioration of the fixing roller surface due to durability and the like can be reduced, and the change in the surface property of the fixed image can be reduced. A color projection image with less dullness of the color image and deterioration of transparency can be obtained.
[0038]
Further, a change in the color space area of the projected color image due to durability is small, and a color projected image with little color space deterioration is obtained.
[0039]
When the ratio (G′155 / G′190) of the storage elastic modulus (G′155) at a temperature of 155 ° C. to the storage elastic modulus (G′190) at a temperature of 190 ° C. is less than 0.95, the resin Is too large to deteriorate the color mixing property, and if it exceeds 5.0, it is apt to be affected by deterioration of the surface of the fixing roller due to durability and the like because of excellent sharp melt property. In addition, the transparency of the OHP projected image may be reduced due to durability.
[0040]
In the present invention, the storage elastic modulus (G'155) at a temperature of 155 ° C. of the toner is preferably 8.5 × 10 5³~ 9 × 10⁴dyn / cm², More preferably 9 × 10³~ 8 × 10⁴dyn / cm², More preferably 9 × 10³~ 7 × 10⁴dyn / cm²Good to be.
[0041]
The storage elastic modulus (G′155) at a temperature of 155 ° C. of the toner is 8.5 × 10³dyn / cm²If it is less than 10, the sharp melt property of the toner is too large, so that it becomes difficult to maintain OHP transparency due to durability.⁴dyn / cm²When the value exceeds, the elasticity term of the toner is weak, and the transparency of OHP, particularly, the dullness of the halftone portion is large.
[0042]
In the present invention, the storage elastic modulus (G′190) at a temperature of 190 ° C. of the toner is preferably 8 × 10²To 8.4 × 10³dyn / cm², More preferably 1 × 10³~ 8.2 × 10³dyn / cm², Even more preferably 1.5 × 10³~ 8 × 10³dyn / cm²Good to be.
[0043]
The storage elastic modulus (G′190) at a temperature of 190 ° C. of the toner is 8 × 10²dyn / cm²When the value is less than, the high-temperature offset resistance in fixing is weak, the roller surface deteriorated due to durability is easily affected, and the effect on OHP transparency is large.³dyn / cm²In the case where the ratio exceeds 1, the elasticity of the toner is large, so that the smoothness of the surface of the fixed image is insufficient, and the transparency of the OHP, particularly, the dullness of the halftone portion becomes large.
[0044]
Further, in the toner used in the present invention, 1 × 10⁹(Dyn / cm²) Or more [more preferably, 1 × 10⁹~ 1 × 10¹⁰(Dyn / cm²)] (G "_max) Is preferable from the viewpoint of improving the blocking resistance and the durability of a large number of sheets of the toner. The maximum value (G ″) of the loss elastic modulus at a temperature of 40 to 70 ° C._max) And the loss modulus (G ″ 40) of the toner at a temperature of 40 ° C. (G ″)._max/ G ″ 40) is preferably 1.50 or more, more preferably 1.52 to 5.00, and even more preferably 1.55 to 4.00.
[0045]
The local maximum value (G ″) in the temperature range of 40 to 70 ° C. in the loss elastic modulus curve of the toner._{ma x}) Is 1 × 10⁹(Dyn / cm²If the value is less than (), blocking tends to occur due to heat generated by rubbing in the developing device.
[0046]
Further, the maximum value (G ″) of the loss elastic modulus of the toner at a temperature of 40 to 70 ° C._max) And the loss modulus (G ″ 40) of the toner at a temperature of 40 ° C. (G ″)._max/ G ″ 40) is less than 1.5, the effect on the storage elasticity is large, and the aforementioned gradient of G′60 / G′80 at 60 ° C. to 80 ° C. is reduced. In this case, the image becomes a dull image of the halftone portion.
[0047]
Measurement of rheological properties of toner
Using a viscoelasticity measuring device (rheometer) RDA-II type (manufactured by Rheometrics), under the following conditions, the storage elastic modulus G ′ and the storage elastic modulus (G ′) in the temperature range of 30 to 200 ° C. The intersection (Tc) with the loss elastic modulus (G ″) is measured.
[0048]
-Measurement jig: Use a parallel plate with a diameter of 7.9 mm when the elastic modulus is high and 25 mm when the elastic modulus is low.
[0049]
Measurement sample: After heating and melting the toner, the toner is molded into a cylindrical sample having a diameter of about 8 mm and a height of 1.5 to 5 mm, or a disk-shaped sample having a diameter of about 25 mm and a height of 1.5 to 3 mm.
[0050]
Measurement frequency: 6.28 radians / second
-Measurement distortion setting: After setting the initial value to 0.1%, measure in the automatic measurement mode.
[0051]
-Elongation correction of sample: Adjust in the automatic measurement mode.
[0052]
Measurement temperature: The temperature is raised from 25 ° C to 210 ° C at a rate of 2 ° C per minute.
[0053]
Further, in the present invention, a low softening point substance having a melting point of 40 ° C. to 120 ° C. is preferably contained in the surface coat layer forming the laminate sheet.
[0054]
The low softening point substance used in the present invention is characterized by having a melting point preferably in the range of 40 ° C to 120 ° C, more preferably in the range of 50 ° C to 120 ° C. When the melting point of the low softening point substance is lower than 40 ° C., the resulting light-transmissive recording material tends to block during storage, resulting in poor preservability. When the melting point exceeds 120 ° C., the recording material is fixed. Sufficient releasability from the means is not exhibited, and furthermore, the melting of the molten toner and the surface layer surface during fixing of the toner image becomes insufficient, and the resulting light-transmissive recording material is irregularly reflected by the boundary surface. It is not preferable because image quality is reduced.
[0055]
In the present invention, the melting point of the low softening point substance was measured by DSC. Specifically, the DSC was measured using Perkin Elmer's DSC-7 according to ASTM D-3418-82. In the present invention, the DSC curve at this time uses the DSC curve measured when the temperature was raised once, the pre-history was measured, and then the temperature was lowered and increased at a temperature rate of 10 ° C./min, as shown in FIG. The maximum endothermic peak temperature in the DSC curve when the temperature was raised from -100 ° C to 200 ° C was defined as the melting point.
[0056]
Examples of the low softening point substance having the above-mentioned melting point used in the present invention include plant waxes such as carnauba wax, candelilla wax, rice wax and wood wax and derivatives thereof; and mineral waxes such as ceresin wax and montan wax. Waxes and their derivatives (eg, examples of derivatives of montan wax include acid waxes, ester waxes and partially saponified ester waxes); animal waxes such as beeswax, spermaceti and lanolin and derivatives thereof; paraffin wax And waxes such as petroleum waxes and their derivatives such as microcrystalline wax and synthetic waxes and their derivatives such as polyethylene wax and Fischer-Tropsch wax. In addition, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid; higher alcohols such as stearyl alcohol and behenyl alcohol; esters such as fatty acid esters of sucrose and fatty acid esters of sorbitan; amides such as oleylamide Classes may be used in combination with the above waxes.
[0057]
The low softening point substance used in the present invention preferably maintains a dispersed fine particle state in the surface layer in combination with a thermoplastic resin and does not impair the transparency of the recording material.
[0058]
Therefore, as the low softening point substance used in the present invention, the average dispersion diameter of the low softening point substance present in the surface layer is preferably less than 1 μm, more preferably 0.01 μm or more and less than 1.00 μm. It is more preferably within the range of 0.04 μm or more and 0.5 μm or less. If the average dispersion diameter of the release agent is 1 μm or more in the surface layer, the transparency of the surface layer is impaired. In the present invention, the low softening point substance may be completely dissolved in the thermoplastic resin in the surface layer and may be present in the surface layer in that state. In order to exhibit the moldability efficiently, it is preferable to use a low softening point substance in a state where the surface layer has an average dispersion diameter of 0.01 μm or more.
[0059]
In the present invention, in order for the low softening point substance to be present in the surface layer in the form of fine particles having an average dispersion diameter of less than 1 μm in the surface layer, it is necessary to prepare a coating liquid used for forming the surface layer. A coating liquid having an average dispersion diameter of the low softening point substance of less than 1.00 μm, and applying the coating liquid on a light-transmitting substrate; Preferably, it is formed. Further, in the present invention, the dry film formation and the temperature conditions at this time are preferably a temperature not lower than the Tg of the thermoplastic resin and a temperature within a range of ± 40 ° C. from the melting point of the release agent. preferable.
[0060]
The low softening point substance used in the present invention is generally difficult to dissolve in an organic solvent and is difficult to use in a solvent system, especially at room temperature. Therefore, the low softening point substance is prepared in advance as an aqueous dispersion, and this aqueous dispersion is prepared. And an aqueous dispersion of a thermoplastic resin to form a coating liquid, and the coating liquid is preferably used to form a surface layer on the light-transmitting substrate.
[0061]
At this time, as a preferable method for obtaining an aqueous dispersion of the low softening point substance, for example, (1) a method in which water heated near the melting point of the low softening point substance is stirred at 5,000 rpm with a homomixer. And (2) a suspension polymerization method.
[0062]
When the aqueous dispersion of the low softening point substance thus obtained is mixed with the aqueous dispersion of the thermoplastic resin, conditions such as temperature and solid concentration are set so that the viscosity of the aqueous dispersion of the thermoplastic resin becomes 200 cps or less. Is preferably adjusted. If the viscosity of the aqueous dispersion of the thermoplastic resin is larger than 200 cps, the particles of the low softening point substance which are finely dispersed when mixed with the aqueous dispersion of the low softening point substance are not preferable because they are aggregated.
[0063]
In the surface layer thus formed, the fine particles of the low softening point substance are uniformly dispersed in the thermoplastic resin. For this reason, it is considered that the low softening point substance is melted when passing through the heating and fixing means and migrates to the surface of the surface layer to exhibit the releasing effect.
[0064]
The amount of the low softening point substance used for forming the surface layer slightly varies depending on the thickness of the surface layer, but is preferably 0.01% by weight to 30% by weight, and more preferably the total weight of the surface layer. The content is preferably in the range of 0.1% by weight to 30% by weight. When the content of the low softening point substance is less than 0.01% by weight, the releasing effect is insufficient. When the content is more than 30% by weight, the low softening point substance precipitates and the surface layer becomes transparent. The property is impaired, which is not preferable.
[0065]
In general, the material used for the low softening point substance as described above has crystallinity, and particularly, when the degree of crystallinity is high, the transparency tends to decrease significantly. It has been found that if a material having a specific relationship between the Tg of the plastic resin and the melting point of the low softening point substance is selected and used, transparency is improved regardless of the type of material. That is, the melting point of the low softening point substance is preferably higher than the glass transition temperature (Tg) of the thermoplastic resin by 10 ° C. or higher, more preferably higher by 20 ° C. or higher. If the surface layer of the light-transmitting recording material is formed using such a combination of materials, although the reason is not clear, when the recording material passes through the heat fixing roller, the material having a low softening point on the surface of the surface layer is removed. If the melting point of the low softening point material is somewhat higher than the glass transition temperature (Tg) of the thermoplastic resin when microcrystals are formed while being cooled, under the influence of fluctuation due to micro-Brownian motion of the thermoplastic resin, It is presumed that the decrease in the crystallinity of the low softening point material contributes to the improvement in the transparency of the recording material.
[0066]
When the melting point of the low softening point substance is not higher than the glass transition temperature (Tg) of the thermoplastic resin by 10 ° C. or more, the effect of decreasing the crystallinity is not so large, and the recording material does not easily contribute to transparency. .
[0067]
In the present invention, when the melting point of the low softening point substance is higher than the glass transition temperature (Tg) of the thermoplastic resin by more than 120 ° C., sticking to the fixing roller and blocking at the fixing temperature of the toner occur. , The storage stability is likely to be reduced.
[0068]
With the above configuration, the thermoplastic resin used in the present invention has a softening temperature close to or lower than the fixing temperature of the toner. The toner is easily buried, and as described above, the granularity of the toner is improved, the smoothness of the image surface is improved, and the transparency of the obtained recording material is improved.
[0069]
Further, in the toner used in the present invention, the low softening point substance is preferably 1 to 40 parts by weight, more preferably 5 to 40 parts by weight, and still more preferably 10 to 35 parts by weight based on 100 parts by weight of the binder resin. A heating and pressing member which is preferably contained in an amount larger than that of a normal toner for heat and pressure fixing, so that the releasing oil is not applied, or the coating amount of the releasing oil is 0.04 mg / sheet (A4) or less. Thereby, the toner image can be fixed on the laminate sheet.
[0070]
When the content of the low softening point substance contained in the toner is less than 1 part by weight, the release oil is not applied, or the application amount of the release oil is 0.04 mg / sheet (A4 size) or less. It is difficult to fix without offset by the heating / pressing fixing member described above, and if it exceeds 40 parts by weight, the transparency of the projected image due to OHP tends to be reduced.
[0071]
In the present invention, the binder resin of the toner has a toluene-soluble component and a toluene-insoluble component, and the toluene-insoluble component is preferably 0.1 to 30% by weight, more preferably 0.1 to 30% by weight, based on the weight of the binder resin. Is preferably 0.5 to 25% by weight.
[0072]
When the toluene-insoluble content of the binder resin of the toner is less than 0.1% by weight, the storage elastic modulus (G′155) at a temperature of 155 ° C. and the storage elastic modulus (G′190) at a temperature of 190 ° C. It is difficult to make the ratio (G'155 / G'190) 0.95 or more, and if it exceeds 30% by weight, the storage elastic modulus (G'155) at a temperature of 155 ° C. and the temperature 190 It is difficult to make the ratio (G'155 / G'190) to the storage modulus (G'190) at 5.0 ° C 5.0 or less.
[0073]
In the present invention, the binder resin of the toner may be polystyrene; styrene-substituted homopolymers such as poly-p-chlorostyrene and polyvinyltoluene: styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer Styrene-vinyl naphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl Styrene copolymers such as ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers Polymer; acrylic resin, Acrylic resins, polyvinyl acetate, silicone resins, polyester resins, polyamide resins, furan resins, epoxy resins, xylene resins.
[0074]
These resins are used alone or as a mixture. As a main component of the binder resin, a styrene copolymer, which is a copolymer of styrene and another vinyl monomer, is preferable in terms of developability and fixability.
[0075]
Comonomers for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, and methacrylic acid. Monocarboxylic acids or substituted products having double bonds such as methyl acrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide; maleic acid, butyl maleate, methyl maleate, dimethyl maleate A dicarboxylic acid having a double bond and a substituted product thereof; a vinyl ester such as vinyl chloride, vinyl acetate and vinyl benzoate; an ethylene olefin such as ethylene, propylene and butylene; Tons, such as vinyl vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, such as vinyl ether vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.
[0076]
The styrene copolymer is preferably crosslinked with a crosslinking agent such as divinylbenzene in order to widen the fixing temperature range of the toner and improve the offset resistance.
[0077]
As the crosslinking agent, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline; Divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These are used alone or as a mixture.
[0078]
When the binder resin contains a crosslinked styrene copolymer as a main component, the binder resin has a molecular weight of 3,000 to 50,000 in the molecular weight distribution by gel permeation chromatography (GPC) of the THF-soluble portion of the binder resin. It is preferred that the region has a main peak in the region and a sub-peak or shoulder in the region having a molecular weight of 100,000 or more. More preferably, it is preferable to have two or more sub-peaks, two or more shoulders, or two or more sub-peaks or a sub-peak and a shoulder in a region having a molecular weight of 100,000 or more. Furthermore, as described above, the binder resin containing a styrene copolymer as a main component preferably contains 0.1 to 30% by weight (more preferably 1 to 15% by weight) of a toluene-insoluble component.
[0079]
The term “toluene-insoluble component” refers to a polymerization ratio of an ultra-high molecular weight polymer component (substantially a crosslinked polymer) insoluble in a toluene solvent in a resin composition in a toner. The toluene-insoluble matter is defined by a value measured as follows.
[0080]
0.5 to 1.0 g of the toner sample is weighed (W1 g), placed in a cylindrical filter paper (for example, No. 86R manufactured by Toyo Roshi Kabushiki Kaisha), subjected to a Soxhlet extractor, and extracted with 100 to 200 ml of toluene as a solvent for 6 hours. After evaporating the soluble component extracted by the solvent, the resultant is vacuum-dried at 100 ° C. for several hours, and the amount of the toluene-soluble resin component is weighed (W2 g). The weight of components other than the resin components such as the pigment and wax in the toner is defined as (W3 g). The toluene-insoluble content is obtained from the following equation.
[0081]
(Equation 1)

[0082]
When the binder resin is a polyester resin, at least one peak is present in the molecular weight distribution of toluene-soluble components by GPC, preferably in the region of 3,000 to 50,000, more preferably in the region of 5,000 to 30,000. A binder resin having a molecular weight of 100,000 or less is preferably 60 to 100% by weight, more preferably 65 to 95%.
[0083]
When there is no peak in a region having a molecular weight of 3,000 to 50,000 and a peak exists in a region having a molecular weight of less than 3,000, blocking resistance at a high temperature is weak, which adversely affects development characteristics.
[0084]
Further, when there is no peak in a region having a molecular weight of 3,000 to 50,000 and a peak exists in a region having a molecular weight of more than 50,000, the fixability at a low temperature tends to deteriorate.
[0085]
When the content of the component having a molecular weight of 100,000 or less is less than 60% by weight, OHP transparency is deteriorated due to the large amount of the high molecular weight component.
[0086]
It is also preferable to use a mixture of a styrene copolymer and a polyester resin as the binder resin. For example, a combination of a cross-linked styrene copolymer and a non-cross-linked polyester resin, and a combination of a cross-linked styrene copolymer and a cross-linked polyester resin are preferable in terms of toner fixability, offset resistance, and color mixing.
[0087]
Polyester resins have excellent fixability and transparency, and are suitable for color toners that require good color mixing. In particular,
[0088]
Embedded image

(Where R₁And R₂Represents an ethylene or propylene group, x and y each represent an integer of 1 or more, and the average value of x + y is 2 to 10. )
And a carboxylic acid component comprising a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof (for example, fumaric acid, maleic acid, maleic anhydride, phthalic acid) Terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, etc.) are preferable.
[0089]
Further, the polyester resin preferably has an acid value of 1 to 35 mgKOH / g, more preferably 1 to 20 mgKOH / g, still more preferably 3 to 15 mgKOH / g, and a hydroxyl value of preferably 2 to 45 mgKOH / g. g, more preferably 3 to 40 mgKOH / g, and still more preferably 4 to 30 mgKOH / g, from the viewpoint of environmental stability of the charging characteristics of the toner.
[0090]
When the acid value of the polyester resin is less than 1 mgKOH / g or the hydroxyl value is less than 2 mgKOH / g, the toner has a low charge-imparting ability and generates a lot of fog in a high-temperature and high-humidity environment. When the acid value of the polyester resin exceeds 35 mgKOH / g or the hydroxyl value exceeds 45 mgKOH / g, the charge is increased in a low-temperature and low-humidity environment, and the image density is significantly reduced.
[0091]
The acid value and the hydroxyl value of the polyester resin are measured by the following measuring methods.
[0092]
[Acid Value] The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids, and the like contained in 1 g of a sample is called an acid value, and the test is performed as follows.
[0093]
(1) Reagent
(A) Solvent Ethyl ether-ethyl alcohol mixed liquid (1 + 1 or 2 + 1) or benzene-ethyl alcohol mixed liquid (1 + 1 or 2 + 1), these solutions were prepared immediately before use using N / 10 potassium hydroxide ethyl alcohol solution using phenolphthalein as an indicator. Neutralize with.
[0094]
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
[0095]
(C) N / 10 potassium hydroxide-ethyl alcohol solution 7.0 g of potassium hydroxide is dissolved in as little water as possible, and ethyl alcohol (95 v / v%) is added to make 1 liter. The standardization is performed in accordance with JIS K 8006 (basic matter regarding titration during content test of reagent).
[0096]
(2) Operation Correctly weigh 1 to 20 g of a sample, add 100 ml of a solvent and a few drops of a phenolphthalein solution as an indicator, and shake thoroughly until the sample is completely dissolved. In the case of a solid sample, dissolve by heating on a water bath. After cooling, the mixture is titrated with an N / 10 potassium hydroxide ethyl alcohol solution, and the end point of neutralization is defined as the point at which the indicator continues to have a faint red color for 30 seconds.
[0097]
(3) Calculation formula The acid value is calculated by the following formula.
[0098]
(Equation 2)

Where A: acid value
B: Usage amount of N / 10 potassium hydroxide ethyl alcohol solution (ml)
f: Factor of N / 10 potassium hydroxide ethyl alcohol solution
S: Sample (g)
[0099]
[Hydroxyl value] When 1 g of a sample is acetylated by a prescribed method, the number of mg of potassium hydroxide required to neutralize acetic acid bound to a hydroxyl group is called a hydroxyl value, and the test is carried out by the following reagent, operation and calculation formula. Do.
[0100]
(1) Reagent
(A) Acetylating reagent 25 g of acetic anhydride is placed in a 100 ml volumetric flask, pyridine is added to make the total volume 100 ml, and the mixture is shaken sufficiently.
[0101]
Acetylating reagents should be kept away from moisture, carbon dioxide and acid vapors and stored in brown bottles.
[0102]
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
[0103]
(C) N / 2 potassium hydroxide-ethyl alcohol solution 35 g of potassium hydroxide is dissolved in a small amount of water as much as possible, and ethyl alcohol (95 v / v%) is added to make 1 liter. Orientation is performed according to JIS K 8006.
[0104]
(2) Procedure 0.5 to 2.0 g of a sample is weighed correctly in a round bottom flask, and 5 ml of an acetylating reagent is correctly added thereto. Place a small funnel over the mouth of the flask and heat the bottom about 1 cm into a glycerin bath at 95-100 ° C. At this time, in order to prevent the temperature of the neck of the flask from rising due to the heat of the bath, a cardboard disc with a round hole is placed over the base of the neck of the flask. After 1 hour, the flask is taken out of the bath, left to cool, 1 ml of water is added from a funnel and shaken to decompose acetic anhydride. In order to further complete the decomposition, the flask was heated again in a glycerin bath for 10 minutes, allowed to cool, and then the funnel and the wall of the flask were washed with 5 ml of ethyl alcohol. Titrate with solution.
[0105]
A blank test is performed in parallel with this test.
[0106]
(3) Calculation formula The hydroxyl value is calculated by the following formula.
[0107]
(Equation 3)

Where A: hydroxyl value
B: Usage amount of blank test N / 2 potassium hydroxide ethyl alcohol solution (ml)
C: N / 2 potassium hydroxide ethyl alcohol solution used in this test (ml)
f: Factor of N / 2 potassium hydroxide ethyl alcohol solution
S: Sample (g)
D: acid value
[0108]
In the present invention, examples of the low softening point substance used in the toner for developing an electrostatic image include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, Fischer-Tropsch wax, amide wax, higher fatty acid, and long-chain alcohol. , Ester waxes and derivatives thereof such as graft compounds and block compounds, and those having a sharp endothermic peak in a DSC endothermic curve from which low molecular weight components have been removed are preferred.
[0109]
Preferred waxes include linear alkyl alcohols having 15 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. It is also preferable that impurities such as liquid fatty acids have been removed from these waxes in advance.
[0110]
Further, a wax preferably used is a low-molecular-weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or polymerized under low pressure using a Ziegler catalyst or other catalyst; an alkylene obtained by thermally decomposing a high-molecular weight alkylene polymer. Polymer; low molecular weight alkylene polymer by-produced when polymerizing alkylene is separated and purified; hydrocarbon polymer distillation residue obtained from synthetic gas consisting of carbon monoxide and hydrogen by the Age method, or obtained carbon A polymethylene wax obtained by extracting and separating a specific component from a synthetic hydrocarbon obtained by hydrogenating a distillation residue of a hydrogen polymer is exemplified. An antioxidant may be added to these waxes.
[0111]
The substance having a low softening point used in the present invention preferably has an endothermic main peak in a temperature range of preferably 40 to 90 ° C, more preferably 45 to 85 ° C in a DSC endothermic curve. Further, the endothermic main peak is preferably a sharp-melting low-softening point substance having a half width of preferably within 10 ° C, more preferably within 5 ° C. In particular, an ester wax whose low softening point substance is mainly an ester compound of a long-chain alkyl alcohol having 15 to 45 carbon atoms and a long-chain alkyl carboxylic acid having 15 to 45 carbon atoms is preferable.
[0112]
In the DSC endothermic curve of the low softening point substance, if the endothermic main peak exists in a temperature range of less than 40 ° C., the strength of the toner particles is reduced, and the development characteristics during a durability test are likely to be reduced. Also, the blocking resistance is weak.
[0113]
In addition, when it exists in a temperature range exceeding 90 ° C., the fixing start point at a low temperature becomes high. Further, for example, when used in a polymerization method toner, the granulation property deteriorates.
[0114]
In the present invention, as the endothermic main peak of the low softening point substance, DSC measurement is performed in accordance with ASTM D3418-8, and the maximum endothermic peak value in the measured DSC endothermic curve is used.
[0115]
In the present invention, particularly preferred low softening point substances are those represented by the following constitutions.
[0116]
Embedded image

[Wherein, R₁And R₂Represents an organic group having 1 to 40 carbon atoms;₁And R₂A and b are integers of 0 to 4, a + b is 4, c and d are integers of 0 to 25, and m and n are 0 at the same time. There is no. ]
[0117]
Embedded image

[Wherein, R₃And R₄Represents an organic group having 1 to 40 carbon atoms;₃And R₄Is 3 or more, and R₅Represents a hydrogen atom or an organic group having 1 or more carbon atoms, e and f each represent an integer of 0 to 3, e + f represents an integer of 1 to 3, and when e + f is 2, R₃And R₄Is an organic group having 1 or more carbon atoms, g and h each represent an integer of 0 to 25, g and h are not simultaneously 0, i represents an integer of 1 to 3, e + f + i is 4. ]
[0118]
Embedded image

[Wherein, R₆And R₈Represents an organic group having 6 to 32 carbon atoms;₆And R₈Are the same or different, and R₇Represents an organic group having 1 to 20 carbon atoms. ]
[0119]
Embedded image

[Wherein, R₉And R₁₁Represents an organic group having 6 to 32 carbon atoms;₉And R₁₁Are the same or different, and R₁₀Is
[0120]
Embedded image

(In the formula, j and k each represent an integer of 1 to 10, and 1 represents an integer of 1 to 20.) ]
[0121]
Embedded image

[Wherein, R₁₁Represents an organic group having 1 to 40 carbon atoms, m represents an integer of 0 to 4, n represents an integer of 1 to 4, m + n is 4, o and p represent integers of 0 to 25, o and p never become 0 at the same time. ]
[0122]
In the above structural formula, specific examples of the organic group include an alkyl group, an acyl group, an acyloxy group, an aryl group, an alkoxyl group, and an aldoketene group.
[0123]
As the black colorant used in the present invention, carbon black, a magnetic substance, and those toned to black using a yellow colorant, a magenta colorant, and a cyan colorant shown below are used.
[0124]
As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 168, 174, 176, 180, 181 and 191 are preferably used.
[0125]
Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.
[0126]
As the cyan coloring agent, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be particularly preferably used.
[0127]
These black colorant, yellow colorant, magenta colorant and cyan colorant can be used alone or as a mixture or in the form of a solid solution. In the present invention, the colorant is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, transparency on the OHP film, and dispersibility in toner particles. In the present invention, the content of carbon black, yellow colorant, magenta colorant, and cyan colorant as the black colorant in the toner is preferably 1 to 20 parts by weight per 100 parts by weight of the binder resin.
[0128]
When a magnetic material is used as the black colorant, the content of the colorant in the toner is different from other colorants, and is preferably 40 to 150 parts by weight per 100 parts by weight of the binder resin.
[0129]
As the charge control agent used to stabilize the frictional charging characteristics of the toner, a charge control agent that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Further, in the case of using a polymerized toner production method in which a toner composition is formed by polymerizing a monomer composition containing a polymerizable monomer in an aqueous medium as a method for producing toner particles, there is no aqueous Charge control agents that are free of solubilizers in the medium are particularly preferred. Specifically, examples of the negative control agent include salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, a metal compound of dicarboxylic acid, sulfonic acid, a polymer compound having a carboxylic acid in a side chain, a boron compound, and a urea compound. , A silicon compound, carrick's arene, etc., and as the positive control agent, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound and the like are preferably used. . The content of these charge control agents in the toner is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the binder resin. However, in the present invention, the addition of the charge control agent to the toner is not essential, and in the case of using the two-component developing method, utilizing the triboelectric charging with the carrier and using the non-magnetic one-component blade coating developing method. The toner particles need not necessarily contain a charge control agent by positively utilizing frictional charging with a blade member or a sleeve member.
[0130]
As one of the methods for producing the toner for developing an electrostatic image of the present invention, a binder resin, a colorant, a low softening point substance, a charge control agent and other internal additives as other optional components, a pressure kneader, After kneading using an extruder or a media dispersing machine and uniformly dispersing, it is made to pulverize to the desired toner particle size by colliding with the target mechanically or under a jet stream, and then subjected to a classification process to There is a toner production method by a pulverization method for producing toner particles with a sharp distribution. In addition, the monomer particles described in JP-B-36-10231, JP-A-59-53856 and JP-A-59-61842 are polymerized in an aqueous medium to form toner particles. A method of forming toner particles by using a suspension polymerization method to form; agglomeration of at least one kind of fine particles as disclosed in JP-A-62-106473 and JP-A-63-186253. An interfacial association method for obtaining toner particles of a desired particle size by polymerizing the monomer composition in an organic solvent in which the monomer is soluble and the monomer is polymerized in an insoluble organic solvent A dispersion polymerization method for producing toner particles by causing the monomer composition to polymerize in the presence of a water-soluble polymerization initiator to form toner particles; and a toner polymerization method represented by a soap-free polymerization method. Manufacturing.
[0131]
When the toner particles used in the present invention are produced by a pulverizing method, a binder resin having a high molecular weight and a low molecular weight are blended and used, and if necessary, the type and amount of the low softening point substance are added. It is preferred to control the viscoelastic properties of the toner by changing In particular, it is possible to use a binder resin having a hydroxyl group or a carboxyl group as a binder resin and add an organometallic compound or a derivative thereof during kneading to cause metal crosslinking, thereby producing a THF-insoluble substance. When the toner particles used in the present invention are produced by a polymerization method, an appropriate crosslinking agent and / or a resin component are added to the polymerizable monomer, and a low softening point substance and a polymerization initiator are further added and dissolved. It is preferable to granulate the obtained monomer composition in an aqueous medium, further carry out a polymerization reaction, and encapsulate a low softening point substance in toner particles with the polymerized polymer to form a sea-island structure. .
[0132]
As a method of encapsulating a low softening point substance with a binder resin and constructing a sea-island structure, the polarity of the low softening point substance is set to be smaller than that of the main monomer in an aqueous medium, and a small amount of A method of obtaining toner particles having a core-shell structure in which a low softening point substance is coated with a binder resin by adding a large resin or monomer and polymerizing the polymerizable monomer is exemplified. The toner particles having the core-shell structure may be used as the toner particles as they are, or the toner particles having the sea-island structure may be formed by aggregating and assembling the ultrafine toner particles to a desired particle size. Is also good. When a sea-island structure is constructed using these methods, it is preferable that at least one of the low softening point substances has a melting point (the maximum endothermic peak temperature in a DSC endothermic curve) lower than the polymerization temperature.
[0133]
By encapsulating the low softening point substance in the toner particles, even if the toner particles contain a relatively large amount of the low softening point substance, a decrease in the blocking resistance of the toner can be suppressed, and the sharp melt property can be reduced. By using the low softening point material, toner particles having a strong mechanical impact and capable of producing toner particles having low-temperature fixability and good mixing properties during heat and pressure fixing can be produced.
[0134]
In the present invention, a vinyl polymerizable monomer capable of radical polymerization is used as the polymerizable monomer used when the toner is produced by the polymerization method. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used. As the monofunctional polymerizable monomer, styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimerstyrene, pn-butylstyrene , P-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p- Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2- Ethylhexyl acrylate, acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate , N-nonyl methacrylate, diethyl phosphate ethyl methacrylate And methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate and vinyl formate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.
[0135]
Examples of polyfunctional polymerizable monomers include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tripropylene glycol. Diacrylate, polypropylene glycol diacrylate, 2,2'-bis [4- (acryloxydiethoxy) phenyl] propane, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis [4- (methacryloxydiethoxy) phenyl] Examples include propane, 2,2′-bis [4- (methacryloxypolyethoxy) phenyl] propane, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like.
[0136]
In the present invention, the above-mentioned monofunctional polymerizable monomers are used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers are used in combination. I do. Polyfunctional polymerizable monomers can also be used as crosslinking agents.
[0137]
As the polymerization initiator used in the polymerization of the above-mentioned polymerizable monomer, an oil-soluble initiator and / or a water-soluble initiator are used. For example, examples of the oil-soluble initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, and 1,1′-azobis (cyclohexane-1-carbonitrile). Azo compounds such as 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanoyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumylper Kisaido, t- butyl hydroperoxide, di -t- butyl peroxide, include peroxide initiators such as cumene hydroperoxide.
[0138]
Examples of the water-soluble initiator include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, and 2,2′-azobis (2-aminodinopropane) hydrochloride Salts, azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.
[0139]
In the present invention, in order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor and the like may be further added and used.
[0140]
In the present invention, as a method for producing a toner, there is provided a suspension which can uniformly control the shape of toner particles, easily obtain a sharp particle size distribution, and easily obtain toner particles having a small particle size of 3 to 8 μm. A polymerization method is particularly preferred. Further, a seed polymerization method in which a monomer is further adsorbed onto the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention. At this time, it is also possible to use a compound having polarity dispersed or dissolved in the monomer to be adsorbed. When suspension polymerization is used as a method for producing toner particles, toner particles can be directly produced from the monomer composition by the following production method. A low-softening point substance such as wax, a colorant, a polymerization initiator, a crosslinking agent, and other additives are added to the monomer, and the monomer composition is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like. Is dispersed in an aqueous medium containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the stirring speed and time are adjusted so that the droplets of the monomer composition have the desired size of the toner particles, and the granulation is performed. After that, by the action of the dispersion stabilizer, the stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, usually 50 to 90 ° C. (preferably 55 to 85 ° C.). The temperature may be raised in the latter half of the polymerization reaction, and furthermore, in order to remove unreacted polymerizable monomers and by-products that cause odor at the time of fixing of the toner, one half of the reaction or one after the completion of the reaction. The partial aqueous medium may be distilled off. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried.
[0141]
In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition. Examples of dispersants used include inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and calcium metasilicate. Examples thereof include calcium sulfate, barium sulfate, bentonite, silica, and alumina. As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used. It is preferable to use 0.2 to 2.0 parts by weight of these dispersants based on 100 parts by weight of the polymerizable monomer.
[0142]
As these dispersants, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, an inorganic oxide can be formed in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. A surfactant of 0.001 to 0.1% by weight may be used in combination for making these dispersants finer. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.
[0143]
As the toner of the present invention, a toner having a shape factor SF-1 value of 100 to 160, more preferably 100 to 150, and still more preferably 100 to 125 is preferable.
[0144]
In the present invention, SF-1 representing a shape factor is, for example, 100 samples of a toner image enlarged at a magnification of 500 times are sampled at random using a FE-SEM (S-800) manufactured by Hitachi, Ltd. Is introduced into, for example, an image analysis device (LuzexIII) manufactured by Nicole, and analyzed, and a value obtained by the following equation is defined as a shape factor SF-1.
[0145]
(Equation 4)

[Where MXLNG indicates the absolute maximum length of the toner particles, and AREA indicates the projected area of the toner particles. ]
[0146]
The shape factor SF-1 indicates the degree of roundness of the toner particles. A toner having a toner shape factor SF-1 larger than 160 gradually changes from a spherical shape to an irregular shape, and a decrease in transfer efficiency is observed as the shape factor SF-1 decreases.
[0147]
Lubricant powders such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder; abrasives such as cerium oxide, silicon carbide, strontium silicate, calcium titanate, strontium titanate; silica, titanium oxide Fluidity improver such as aluminum oxide: anti-caking agent: It is preferable to externally add a conductivity-imparting agent such as carbon black, zinc oxide and tin oxide.
[0148]
In particular, inorganic fine powders such as silica fine powder, titanium oxide fine powder, aluminum oxide fine powder, strontium silicate fine powder, calcium titanate fine powder, and strontium titanate fine powder are preferable as the inorganic fine powder. The inorganic fine powder is preferably hydrophobized with a hydrophobizing agent such as a silane coupling agent, silicone oil, or a mixture thereof. The external additive is preferably used in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the toner particles.
[0149]
Next, an example of a laminate sheet used in the present invention will be described with reference to FIG.
[0150]
In FIG. 1, A shows a base sheet mainly composed of a heat-resistant resin, and B shows a surface coat layer mainly composed of a thermoplastic resin. In the present invention, the main component refers to a component contained in an amount of 50% by weight or more based on all constituent components.
[0151]
The base sheet A needs to have heat resistance that does not cause significant thermal deformation due to heating during heat fixing or heat and pressure fixing. The heat distortion temperature of the base sheet A used in the present invention is 4.6 kg / cm described in ASTM D684.²The measurement conditions are preferably 145 ° C. or higher, more preferably 150 ° C. or higher. More specifically, the base sheet A used in the present invention has a heat distortion temperature of 145 ° C. or more under the above-described measurement conditions, and a resin having a maximum use temperature of 100 ° C. or more, such as polyethylene. Examples include terephthalate (PET), polyester, polyamide or polyimide. Among these, polyethylene terephthalate is particularly preferred in terms of heat resistance and transparency.
[0152]
The thickness of the base sheet A made of the above-mentioned material needs to be thick enough to prevent wrinkles even when the film is softened by heating during image fixing. For example, in the case of polyethylene terephthalate, the thickness is 50 μm or more. I just need. Further, even when the film is a light-transmitting film, the light transmittance decreases as the thickness increases, so that the thickness of the base sheet A is preferably 50 to 300 μm, more preferably 70 to 200 μm, and still more preferably 100 to 150 μm. It is preferable to use a material having a size of about.
[0153]
In the laminate sheet used in the present invention, a coat layer B mainly composed of a thermoplastic resin is formed on the base sheet A as described above. In the present invention, as a method for forming the coat layer B, a coating solution comprising a material for forming the coat layer B dissolved in an organic solvent is applied by a coating method such as a bar coating method, a dipping method, a spray method, and a spin coating method. A method of applying to the surface of the light-transmitting base sheet A by a method and drying at room temperature or by heating. Further, in order to improve the adhesion between the heat-resistant resin A as the base layer and the coat layer B, a surface treatment such as a plasma treatment or a corona discharge treatment is performed, or the heat-resistant resin layer A and the coat layer B It is also preferable to form an easily adhesive layer between them.
[0154]
Here, as the resin that can be used as the easy-adhesion layer, for example, a resin such as a polyester resin, an acrylate resin, a methacrylate resin, a styrene-acrylate copolymer, a styrene-methacrylate copolymer, or the like. Is mentioned.
[0155]
Next, the constituent material of the coat layer B of the laminate sheet of the present invention will be described in detail. First, the thermoplastic resin used in the present invention will be described. The thermoplastic resin which is a forming material of the coat layer B is, for example, a conventionally known polyester resin, polymethyl methacrylate resin, acrylic resin, styrene resin, styrene-acryl resin, rubber resin, epoxy resin, Various thermoplastic resins such as a vinyl chloride resin, a vinyl acetate resin, and a polyurethane resin, and those using a cross-linking agent therefor are exemplified.
[0156]
In the present invention, a thermoplastic resin having a number average molecular weight in the range of 3,000 to 500,000, more preferably 5,000 to 200,000 is suitably used. In other words, if it is smaller than 3,000, sticking of the laminate sheet to the surface of the fixing means becomes remarkable, and if it is larger than 500,000, the softening property of the coat layer B at the time of heating and fixing is insufficient, and toner particles are buried in the coat layer. As a result, the effect of reducing the granularity of the toner is impaired, the image quality is reduced, and the coating liquid used for forming the coating layer B has a high viscosity. It is not preferable because it lowers the workability.
[0157]
In the present invention, the number average molecular weight of the thermoplastic resin was determined from the molecular weight distribution measured by GPC. The GPC measurement was performed by GPC-150C (manufactured by Waters) under the following conditions. That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) was passed through the column at this temperature at a flow rate of 1 ml per minute as a solvent to prepare a sample concentration of 0.05 to 0.6% by weight. The measurement is performed by injecting 50 to 200 μl of a THF sample solution of the resin. Then, the molecular weight distribution of the sample is determined from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number, and the molecular weight is calculated. As a standard polystyrene sample for preparing a calibration curve, a commercially available standard polystyrene manufactured by Tosoh Corporation was used.², 2.1 × 10³, 4 × 10³, 1.75 × 10⁴, 5.1 × 10⁴, 1.1 × 10⁵3.9 × 10⁵, 8.6 × 10⁵, 2 × 10⁶, 4.48 × 10⁶Was used. The detector used was an RI (refractive index) detector, and the column used was a combination of TSKgel G1000H, G2000H, and G3000H manufactured by Tosoh Corporation.
[0158]
Further, the thickness of the coat layer B made of the constituent materials as described above varies depending on the particle size of the toner to be fixed, but is preferably 2 to 50 μm, more preferably 2 to 30 μm, and further preferably The thickness is preferably 3 to 30 μm, and more preferably 3 to 15 μm. The optimum thickness of the coat layer B is also limited by the translucency and image blur, but since the coat layer has flexibility, there is no fear that even if the coat layer becomes thick, cracks in the image will occur.
[0159]
In the laminate sheet used in the present invention, an antistatic agent is mixed or coated with an antistatic agent in the surface coat layer B, and the surface resistivity is an area suitable for toner transfer.⁷~ 13^ThirteenAdjustment to Ω is preferred.
[0160]
In the present invention, the surface resistivity was measured in accordance with JIS K 6911. Actually, R8340A and R12702A manufactured by Advantest were used at a temperature of 20 ° C., a humidity of 60% RH, and a voltage of 100 V. Incidentally, the unit of the surface resistivity is customarily “Ω / □” in order to avoid confusion with the volume resistivity (Ωcm), but in the present invention, “Ω” is based on JIS K 6911. Used.
[0161]
As the antistatic agent used at this time, any of conventionally known antistatic agents can be used, for example, quaternary ammonium salt compounds, pyridinium salt compounds, phosphonium salt compounds, alkyl betaine compounds, alkylimidazoline Compounds, alkylalanine compounds, polyoxyethylene type nonionic compounds, polyhydric alcohol type nonionic compounds, conductive resins such as polyvinylbenzyl type cations and polyacrylic acid type cations, SnO₂And SnO₂One in which ultrafine metal oxide particles such as -Sb are dispersed in a binder resin is exemplified. These antistatic agents can be mixed in a coating solution for forming the surface coat layer and applied simultaneously, or after the surface coat layer is formed, a solution in which the above antistatic agent is dissolved in alcohol or the like can be applied to form an antistatic agent. Preferably, a layer is formed. The antistatic layer may be formed on the surface coat layer B or between the base sheet A and the surface coat layer B.
[0162]
The laminate sheet used in the present invention comprising the above constituent materials is required to be excellent in transparency, and the light transmittance is such that the total light transmittance as an OHP sheet is at least 80% or more, preferably 85% or more. And the haze is at least 10 or less, preferably 7 or less, more preferably 3 or less.
[0163]
The measurement of transparency in the present invention was performed in accordance with JIS K-7105.
[0164]
The image forming method of the present invention can be applied to all the electrophotographic systems using the toner described above, such as a color copying machine, a color printer, and a color facsimile. Further, the image forming method of the present invention can be preferably applied to a fixing means which does not apply releasability such as oil to the fixing means. However, a toner prepared by a conventional pulverization method is used, and The present invention can also be applied to an electrophotographic system using a conventional fixing means in which a mold agent is separately applied.
[0165]
Hereinafter, an image forming apparatus capable of performing the image forming method of the present invention will be described in detail with reference to FIGS.
[0166]
The color electrophotographic apparatus shown in FIG. 6 includes a transfer material transport system I provided from the right side of the apparatus main body to a substantially central portion of the apparatus main body, and the transfer material transport system I at a substantially central portion of the apparatus main body. The latent image forming section II is provided in the vicinity of the transfer drum 615 and the developing means (that is, the rotary developing device) III is provided in the vicinity of the latent image forming section II. Is done.
[0167]
The transfer material transport system I has the following configuration. An opening is formed in a right wall (right side in FIG. 6) of the apparatus main body, and detachable transfer material supply trays 602 and 603 are provided in the opening so as to partially protrude outside the apparatus. Paper feed rollers 604 and 605 are disposed almost directly above the trays 602 and 603, and are linked to the paper feed rollers 604 and 605 and a transfer drum 605 rotatable in the direction of arrow A disposed to the left. For this purpose, a paper feed roller 606 and paper feed guides 607 and 608 are provided. In the vicinity of the outer peripheral surface of the transfer drum 615, a contact roller 609, a gripper 610, a transfer material separating charger 611, and a separation claw 612 are sequentially arranged from the upstream side to the upstream side in the rotation direction.
[0168]
On the inner peripheral side of the transfer drum 615, a transfer charger and a transfer material separating charger are provided. A transfer sheet (not shown) formed of a polymer, such as polyvinylidene fluoride, is attached to a portion of the transfer drum 615 around which the transfer material is wound, and the transfer material is electrostatically placed on the transfer sheet. It is stuck on. At the upper right side of the transfer drum 615, a conveyor belt unit 616 is provided in close proximity to the separation claw 612, and at the end (right side) of the conveyor belt unit 616 in the transfer material transfer direction (right side), a fixing device 618 is provided. I have. A discharge tray 617 that extends outside the apparatus main body 601 and is detachable from the apparatus main body 601 is provided further downstream of the fixing device 618 in the transport direction.
[0169]
Next, the configuration of the latent image forming section II will be described. A photosensitive drum (for example, an OPC photosensitive drum) 619, which is a latent image carrier rotatable in the direction of the arrow in FIG. 6, is provided with its outer peripheral surface in contact with the outer peripheral surface of the transfer drum 615. Above the photosensitive drum 619 and in the vicinity of the outer peripheral surface thereof, a charge removing charger 620, a cleaning unit 621, and a primary charger 623 are sequentially arranged from the upstream side to the downstream side in the rotation direction of the photosensitive drum 619. An image exposure unit 624 such as a laser beam scanner for forming an electrostatic latent image on the outer peripheral surface of the photosensitive drum 619 and an image exposure reflection unit 625 such as a mirror are provided.
[0170]
The configuration of the rotary developing device III is as follows. A rotatable housing (hereinafter referred to as a “rotating body”) 626 is provided at a position facing the outer peripheral surface of the photosensitive drum 619, and four types of developing devices are provided in the rotating body 626 at four positions in the circumferential direction. And visualizes (ie, develops) the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 619. The four types of developing devices include a yellow developing device 627Y, a magenta developing device 627M, a cyan developing device 627C, and a black developing device 627BK, respectively.
[0171]
The sequence of the entire image forming apparatus having the above-described configuration will be described by taking a full color mode as an example. When the above-described photosensitive drum 619 rotates in the direction of the arrow in FIG. 6, the photosensitive drum 619 is charged by the primary charger 623. In the apparatus shown in FIG. 6, the peripheral speed of the photosensitive drum 619 (hereinafter referred to as process speed) is 100 mm / sec or more (for example, 130 to 250 mm / sec). When the photosensitive drum 619 is charged by the primary charger 623, image exposure is performed by the laser beam E modulated by the yellow image signal of the original 628, and an electrostatic latent image is formed on the photosensitive drum 619, and the rotation is performed. By the rotation of the body 626, the electrostatic latent image is developed by the yellow developing device 627Y fixed at the developing position in advance, and a yellow toner image is formed.
[0172]
The transfer material conveyed via the paper feed guide 607, the paper feed roller 606, and the paper feed guide 608 is held by the gripper 610 at a predetermined timing, and is opposed to the contact roller 609 and the contact roller 609. The electrode is electrostatically wound around the transfer drum 615 by the electrodes. The transfer drum 615 rotates in the direction of the arrow in FIG. 6 in synchronization with the photosensitive drum 619, and the yellow toner image formed by the yellow developing device 627Y is formed on the outer peripheral surface of the photosensitive drum 619 and the outer peripheral surface of the transfer drum 615. Is transferred onto the transfer material by the transfer charger 613 at the portion where the contact is made. The transfer drum 615 continues to rotate as it is to prepare for the transfer of the next color (magenta in FIG. 6).
[0173]
The photosensitive drum 619 is neutralized by the neutralizing charger 620, and is cleaned by the cleaning means 621 using a cleaning blade. Then, the photosensitive drum 619 is charged again by the primary charger 623, and image exposure is performed by the next magenta image signal. A latent image is formed. The rotary developing device rotates while an electrostatic latent image is formed on the photosensitive drum 619 by image exposure based on a magenta image signal, and places the magenta developing device 627M at the above-described predetermined developing position, and Develop with magenta toner. Subsequently, the above-described process is performed for cyan and black colors, respectively. When the transfer of the four-color toner image is completed, the three-color visual image formed on the transfer material is charged to each of the chargers 622 and 614. , The gripping of the transfer material by the gripper 610 is released, and the transfer material is separated from the transfer drum 615 by the separation claw 612, sent to the fixing device 618 by the transport belt 616, and fixed by heat and pressure. Then, a series of full-color print sequences is completed, and a required full-color print image is formed on one surface of the transfer material.
[0174]
Next, another image forming method will be described more specifically with reference to FIG.
[0175]
In the apparatus system shown in FIG. 7, developers having a cyan toner, a developer having a magenta toner, a developer having a yellow toner, and a black A developer having toner is introduced, and the electrostatic charge image formed on the photoconductor 71 is developed by a magnetic brush development method or a non-magnetic one-component development method, and a toner image of each color is formed on the photoconductor 71. The photoreceptor 71 is made of Se, Cds, ZnO₂, OPC, a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Si. The photoreceptor 71 is rotated in the direction of the arrow by a driving device (not shown).
[0176]
As the photosensitive member 71, a photosensitive member having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.
[0177]
The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generating substance and a substance having charge transport performance in the same layer, or a functional separation type photosensitive layer in which the charge transport layer is a component of the charge generating layer. May be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.
[0178]
As the binder resin of the organic photosensitive layer, a polycarbonate resin, a polyester resin, and an acrylic resin are particularly excellent in transferability and cleaning property, and poor cleaning, fusion of a toner to a photoconductor, and filming of an external additive hardly occur.
[0179]
In the charging step, there are a system that is not in contact with the photoconductor 71 using a corona charger, and a contact system that uses a roller or the like, and both systems are used. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 7 is preferably used.
[0180]
The charging roller 72 has a basic configuration including a central core bar 72b and a conductive elastic layer 72a that forms the outer periphery thereof. The charging roller 72 is pressed against the surface of the photoconductor 71 with a pressing force, and is driven to rotate as the photoconductor 71 rotates.
[0181]
Preferred process conditions when using a charging roller are as follows: the contact pressure of the roller is 5 to 500 g / cm, and when a DC voltage is superimposed on an AC voltage, the AC voltage is 0.5 to 5 kVpp, The frequency is 50 Hz to 5 kHz, the DC voltage is ± 0.2 to ± 1.5 kV, and when a DC voltage is used, the DC voltage is ± 0.2 to ± 5 kV.
[0182]
Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that high voltage is not required and generation of ozone is reduced.
[0183]
The material of the charging roller and the charging blade as the contact charging means is preferably a conductive rubber, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), or the like can be used.
[0184]
The toner image on the photoconductor is transferred to an intermediate transfer body 75 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The surface of the photoconductor after the transfer is cleaned by cleaning means 79 having a cleaning blade 78.
[0185]
The intermediate transfer member 75 includes a pipe-shaped conductive core 75b and a medium-resistance elastic layer 75a formed on the outer peripheral surface thereof. The core metal 75b may be formed by applying a conductive plating to a plastic pipe.
[0186]
The medium resistance elastic layer 75a is made of an elastic material such as silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber, EPDM (terpolymer of ethylene propylene diene), carbon black, zinc oxide, tin oxide, silicon carbide. And an electric resistance value (volume resistivity) of 10⁵-10¹¹It is a solid or fired fleshy layer adjusted to a medium resistance of Ω · cm.
[0187]
The intermediate transfer member 75 is provided in parallel with the photoconductor 71 and is provided in contact with the lower surface of the photoconductor 71, and rotates in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photoconductor 71.
[0188]
The first color toner image formed and carried on the surface of the photoreceptor 71 passes through a transfer nip portion where the photoreceptor 71 and the intermediate transfer body 75 are in contact with each other. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 75 by the formed electric field.
[0189]
If necessary, the surface of the intermediate transfer body 75 is cleaned by the detachable cleaning means 80 after the transfer of the toner image onto the transfer material. When there is a toner image on the intermediate transfer member, the cleaning unit 80 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.
[0190]
A transfer unit is provided in parallel with the intermediate transfer body 75 and is brought into contact with the lower surface of the intermediate transfer body 75. The transfer unit 77 is, for example, a transfer roller or a transfer belt. Rotate in the clockwise direction of the arrow at the speed. The transfer unit 77 may be provided so as to directly contact the intermediate transfer body 75, or a belt or the like may be provided so as to contact between the intermediate transfer body 75 and the transfer unit 77.
[0191]
In the case of a transfer roller, the transfer roller has a basic configuration including a central core 77b and a conductive elastic layer 77a formed on the outer periphery thereof.
[0192]
A general material can be used for the intermediate transfer member and the transfer roller. By setting the volume specific resistance of the elastic layer of the transfer roller smaller than the volume specific resistance of the elastic layer of the intermediate transfer member, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. At the same time, the winding of the transfer material around the intermediate transfer member can be prevented. In particular, it is particularly preferable that the volume specific resistance of the elastic layer of the intermediate transfer member is at least 10 times the volume specific resistance of the elastic layer of the transfer roller.
[0193]
The hardness of the intermediate transfer member and the transfer roller is measured according to JIS K-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is higher than the hardness of the elastic layer of the intermediate transfer member. Those having a value of from 80 to 80 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. When the hardness of the intermediate transfer member and that of the transfer roller are reversed, a concave portion is formed on the transfer roller side, and the winding of the transfer material around the intermediate transfer member is likely to occur.
[0194]
The transfer unit 77 rotates the intermediate transfer body 75 at a constant speed or a peripheral speed. The transfer material 76 is conveyed between the intermediate transfer member 75 and the transfer means 77, and at the same time, a bias having a polarity opposite to that of the triboelectric charge of the toner is applied to the transfer means 77 from the transfer bias means. Is transferred to the front side of the transfer material 76.
[0195]
The same material as the charging roller can be used as the material of the transfer rotating body. Preferred transfer process conditions are a contact pressure of the roller of 5 to 500 g / cm and a DC voltage of ± 0.2 to ± 10 kV.
[0196]
For example, the conductive elastic layer 77b of the transfer roller has a volume resistance of 10 such as polyurethane or ethylene-propylene-diene-based terpolymer (EPDM) in which a conductive material such as carbon is dispersed.⁶-10¹⁰It is made of an elastic material of about Ωcm. A bias is applied to the core 77a from a constant voltage power supply. The bias condition is preferably ± 0.2 to ± 10 kV.
[0197]
Next, the transfer material 76 is conveyed to a fixing device 81 having a heating roller having a built-in heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller with a pressing force. The toner image is heated and pressed and fixed on the transfer material by passing between the pressure rollers. A fixing method using a heater via a film may be used.
[0198]
The toner image formed by the toner on the laminate sheet by the image forming apparatus shown in FIGS. 6 and 7 is heated and fixed to the laminate sheet by the heat fixing means shown in FIGS. 2 and 3, and the image is formed on the laminate sheet. You.
[0199]
FIG. 2 is a schematic view showing an example of the heat-pressure fixing device used in the present invention. In FIG. 2, reference numeral 1 denotes a heating / pressing fixing unit having a fixing roller 2 and a pressing roller 3. The fixing roller 2 and the pressure roller 3 are pressed against each other with a predetermined pressure, and the recording material 5 having the unfixed toner image 6 passes between the fixing roller 2 and the pressure roller 3. Thereby, heat and pressure are applied to the recording material 5, and the unfixed toner image 6 is fixed on the recording material 5, and as a result, a toner image 7 is formed. The fixing roller 2 is provided with a heating unit 4 such as a halogen heater.
[0200]
The surface of the fixing roller 2 is made of a fluorine-based resin such as tetrafluoroethylene resin (PTFE), perfluoroalkoxy fluororesin (PFA), or fluoroethylene-propylene copolymer (FEP).
[0201]
On the other hand, the heating and pressurizing device of the film heating type is a heating device or image such as a hot roller system, a hot plate system, a belt heating and pressurizing system, a flash heating system, an open heating system, etc., which are known as other heating and pressurizing devices. In comparison with the heat fixing device, the following advantages are provided and the device is effective.
[0202]
(1) In a heating and pressurizing fixing device of a film heating type, since a heating element having a low heat capacity in which a linear heating element having a low heat capacity is formed into a film-like thin film can be used, power consumption is reduced and a wait time is reduced. (Quick start property) is possible, and the temperature inside the machine can be raised.
[0203]
(2) In a heating / pressing fixing device of a film heating type, since a fixing point and a separation point can be set separately, offset can be effectively prevented. In addition, various disadvantages of other system devices can be solved.
[0204]
FIG. 3 is a schematic diagram of a film heating type heating / pressing fixing device (image heating fixing device) having the above-described features.
[0205]
In FIG. 3, reference numeral 203 denotes a heating body (ceramic heater) fixedly supported by a support, and a heat-resistant film (fixing film) 201 is brought into close contact with the heating body 203 by a pressure roller 202 as a pressure rotating body. Slide and transport. Then, as a material to be heated, between the heat-resistant film 201 and the pressure roller 202 in the press-contact nip portion (fixing nip portion) N formed by the heating body 203 and the pressure roller 202 with the heat-resistant film 201 interposed therebetween. The recording material P on which the image is to be fixed is introduced, and is conveyed while holding the press-contact nip N together with the heat-resistant film 201, so that the heat of the heating body 203 is transferred via the heat-resistant film 201 to the recording material P. And the unfixed visible image (toner image) T on the recording material P is heated and fixed on the surface of the recording material P. The recording material P that has passed through the pressure nip N is separated from the surface of the film 201 and is conveyed to the left in the drawing. Reference numeral 204 denotes a felt-shaped pad that is in contact with the heat-resistant film 201. In the apparatus illustrated in FIG. 3, oil is separately supplied to the heat-resistant film 201 by the pad 204.
[0206]
In the present invention, in the heat and pressure fixing device having the above-described configuration, it is preferable not to separately supply a release agent such as silicone oil from the viewpoint of preventing the recording material from sticking after fixing. However, if the amount of the release agent is such that sticking of the recording material after fixing is not a problem, the release agent is applied to the fixing portion between the fixing means and the unfixed toner image on the recording material. It is also possible to fix by heating and pressing while supplying the toner. Specifically, the release agent is supplied by a coating member such as an oil pad (not shown) on the surface of the fixing roller 2 in the pressure fixing device shown in FIG. This is carried out by impregnating a coating member such as an oil pad shown by the above with a release agent such as silicone oil. As the amount of the release agent separately supplied to the fixing unit, the amount of the release agent applied on the recording material is preferably 0.04 mg / sheet (A4 size) or less, more preferably 0.1 mg / sheet (A4 size). It is preferable that the amount is not more than 02 mg / sheet (A4 size).
[0207]
【Example】
Examples of the present invention will be shown below, but the present invention is not limited to these examples.
[0208]
<Example 1>
(Production of Cyan Toner No. 1)
In a two-liter four-necked flask equipped with a high-speed stirrer TK-homomixer, 710 parts by weight of ion-exchanged water and 0.1 mol / Na_ThreePO_Four445 parts by weight of the aqueous solution was added, the number of rotation was adjusted to 12,000, and the mixture was heated to 70 ° C. Here, 1.0 mol / liter-CaCl_Two68 parts by weight of an aqueous solution is gradually added, and a fine hardly water-soluble dispersant Ca is added._Three(PO_Four)_TwoWas prepared.
Styrene monomer 163 parts by weight
・ 21 parts by weight of 2-ethylhexyl acrylate
・ 16 parts by weight of n-butyl acrylate monomer
・ C. I. Pigment Blue 15: 3 14 parts by weight
・ 10 parts by weight of linear polyester
(Phthalic acid-propylene oxide modified bisphenol A)
・ 2 parts by weight of dialkyl salicylate metal compound
・ 0.5 parts by weight of divinylbenzene
.Ester combination of alkyl carboxylic acid having 22 carbon atoms and alkyl alcohol having 22 carbon atoms
SubstanceEster compound                                      30 parts by weight
[0209]
After dispersing the above mixture for 3 hours using an attritor, a dispersion containing 3.0 parts by weight of lauryl peroxide as a polymerization initiator was put into the dispersion medium prepared above, and granulated at 12,000 rpm for 10 minutes. did. Thereafter, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and polymerization was continued at 60 rpm for 10 hours. After the polymerization was completed, the slurry was cooled, and diluted hydrochloric acid was added to remove the dispersant.
[0210]
After further washing and drying, cyan toner particles having a weight average diameter of 6.4 μm were obtained. 100 parts by weight of the above cyan particles and 1.5 parts by weight of hydrophobic silica were mixed with a Henschel mixer, and cyan toner No. 1 was mixed. 1 was obtained.
[0211]
The obtained cyan toner No. FIG. 4 shows a graph of the viscoelastic properties (storage modulus G ′, loss modulus G ″ and tan (δ)) of Table 1, and Table 1 shows the values of the storage modulus G ′ at each temperature.
[0212]
(Production of laminated sheet No. 1)
90 parts of an aqueous polyester emulsion (number average molecular weight: 19,500, Tg: 40 ° C.) as a thermoplastic resin and an aqueous microcrystalline wax emulsion (melting point: 90 ° C.) as a release agent Part and a liquid obtained by mixing the polyester emulsion under the condition of a viscosity of 80 cps as a coating liquid, applied by a bar code method, and dried at 100 ° C. for 10 minutes to obtain a coating film having a dry thickness of 15 μm. A surface layer was formed. Further, a coating solution composed of PQ-50B (manufactured by Soken Kagaku) and isopropyl alcohol having a solid concentration of about 2% is applied to the surface thereon, and dried to obtain a surface resistivity of about 1.2 × 10 5¹⁰Ω (20 ° C., 60% RH). One sheet 1 was obtained.
[0213]
(Image formation and evaluation)
Cyan toner No. 1 and the laminate sheet No. 1 Using a commercially available full-color copier (CLC500: manufactured by Canon Inc.) modified machine at a temperature of 23 ° C. and a humidity of 65% RH at a development contrast of 320 V to form a toner image, The transferred toner image was transferred onto a laminate sheet to obtain an unfixed toner image having a gradation. Unfixed toner image formed on the laminate sheet (toner ride amount 0 to 0.4 mg / cm²2) is heated and pressurized at a fixing temperature of 180 ° C. and a process speed of 40 mm / sec in an external fixing device (no oil coating function; roller diameter 40φ) in which the surface of the roller shown in FIG. A fixed image (imaging sheet) was obtained.
[0214]
The transmittance and haze (cloud value) of the halftone portion of the obtained fixed image were measured.
[0215]
The transmittance was measured using a Shimadzu self-spectrophotometer UV2200 (manufactured by Shimadzu Corporation). And the transmittance of the laminate sheet alone is set to 100%,
For magenta toner: 650 nm
For cyan toner: 500 nm
For yellow toner: 600 nm
The transmittance at the maximum absorption wavelength was measured and evaluated based on the following evaluation criteria.
[0216]
(Evaluation criteria for transmittance)
：: transmittance is 80% or more
：: transmittance is 70% or more and less than 80%
Δ: transmittance is 60% or more and less than 70%
×: transmittance is less than 60%
[0217]
The haze was measured using a haze meter NDH-300A (manufactured by Nippon Shika Kogyo Co., Ltd.), and the difference from the haze of the laminate sheet alone was measured, and evaluated based on the following evaluation criteria.
[0218]
(Haze evaluation criteria)
：: Haze is less than 20%
：: Haze is 20% or more and less than 25%
Δ: Haze is 25% or more and less than 35%
×: Haze is 35% or more
[0219]
Further, in the above-mentioned measuring method, the change in the transmittance and the haze of the image at the initial stage and after 5,000 sheets of durability in each of the halftone portion and the solid portion were evaluated.
[0220]
(Evaluation criteria for the difference between the transmittance of the initial image and the transmittance of the image after 5,000 sheets of durability)
◎: less than 8%
：: 8% or more and less than 12%
Δ: 12% or more and less than 18%
×: 18% or more
(Evaluation standard for difference between haze of initial image and haze of image after 5,000 sheets of durability)
◎: less than 8%
：: 8% or more and less than 12%
Δ: 12% or more and less than 18%
×: 18% or more
[0221]
Further, the transportability of the laminate sheet was evaluated as follows.
[0222]
Cyan toner No. 1 and the laminate sheet No. 1 Using No. 1 in a commercially available full-color copying machine (CLC500; manufactured by Canon Inc.), a toner image was formed by developing at a developing contrast of 320 V in an environment of a temperature of 23 ° C. and a humidity of 65% RH. The toner image was transferred onto a laminate sheet to obtain an unfixed toner image having an image area ratio of 5%. FIG. 2 shows an unfixed image formed on the laminate sheet. Heating and pressure fixing was performed at a fixing temperature of 180 ° C. and a process speed of 40 mm / sec by using an external fixing device (no oil coating function; roller diameter: 40φ) in which the surface of the fixing roller was a fluororesin. At this time, the transportability of the laminate sheet in the external fixing device as the heat fixing device was evaluated based on the following evaluation criteria.
[0223]
(Evaluation criteria for transportability)
：: The laminate sheet passed without being wound around the fixing roller.
Δ: The first part of the laminate sheet was slightly wound around the fixing roller, but passed without any problem using the separation claw pressed against the roller at a pressure of about 10 gf.
X: The laminate sheet was wound around the fixing roller even by using the separation claw pressed against the roller at a pressure of about 10 kf.
[0224]
<Example 2>
The cyan toner No. 1 of Example 1 was used except that a yellow colorant (CI Pigment Yellow 17) was used as the colorant. In the same manner as in the production of yellow toner No. 1 shown in Table 1, 1 was produced. The cyan toner No. used in Example 1 No. 1 in place of Yellow Toner No. 1 and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0225]
<Example 3>
The cyan toner No. of Example 1 was used except that a magenta colorant (CI Pigment Redl22) was used as the colorant. In the same manner as in the production of magenta toner No. 1 shown in Table 1, 1 was produced. Cyan toner No. 1 used in Example 1 Magenta toner no. 1 and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0226]
<Example 4>
Except for using a black colorant (carbon black) as the colorant, the cyan toner No. 1 of Example 1 was used. In the same manner as in the production of Black Toner No. 1 shown in Table 5, 1 was produced.
[0227]
The cyan toner No. used in Example 1 1, yellow toner No. 1 used in Example 2. 1, magenta toner No. 1 used in Example 3 1 and the black toner No. 1 obtained above. A full-color toner was applied on a laminate sheet under the same developing conditions as in Example 1 in a full-color mode using a commercially available full-color copying machine (CLC500; manufactured by Canon Inc.) modified using the four toners of Example 1. An image was formed, and the obtained full-color toner image was transferred onto a laminate sheet to obtain an unfixed full-color toner image having an image density of 5%. The unfixed full-color toner image formed on the laminate sheet was heated and pressed and fixed by the external fixing device shown in FIG. 2 in the same manner as in Example 1 in the same manner as in Example 1. An image free of stickiness with excellent sheet conveying properties and color mixing properties was obtained.
[0228]
The following method was used to show color mixing due to durability. First, the toner riding amount measured by a spectral radiance meter PR650 (manufactured by Photo Research) is 0 to 0.4 mg / cm.²The color space of the projected image of the fixed OHP of the unfixed image is obtained. Next, the color space (a^*, B^*) Is set to 100, and the color space area of the durable projected image of the embodiment and the color space of the durable projected image at the initial stage of the comparative example are obtained. Table 6 shows the evaluation results.
[0229]
In addition, 100 indicates that the color mixing property is good, and indicates that the color mixing property deteriorates as the number decreases.
[0230]
<Example 5>
Except that the amount of divinylbenzene used as a crosslinking agent was set to 1.0 part by weight, the cyan toner No. 1 of Example 1 was used. No. 1 in the same manner as in the production of No. 1. 2 was produced. Cyan toner No. 1 used in Example 1 1 and cyan toner No. 1 2, and image formation and evaluation were performed in the same manner as in Example 1.
[0231]
<Example 6>
In Example 1, the cyan toner No. Used in the manufacture of 1Ester compoundA diester compound of an alkyl dicarboxylic acid having 18 carbon atoms and an alkyl alcohol having 18 carbon atoms as a main componentEster compound, Except that the cyan toner No. of Example 1 was replaced. No. 1 in the same manner as in the production of No. 1. 3 was prepared. The cyan toner No. used in Example 1 1 in place of cyan toner No. 1 3, and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0232]
<Example 7>
Except that the release agent was changed to stearic acid amide emulsion (melting point: 100 ° C.), laminated sheet No. The same preparation as in Laminate Sheet No. 1 was performed. 2 was obtained.
[0233]
The laminate sheet No. used in Example 1 was used. No. 1 in place of the laminate sheet No. 2, and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0234]
Example 8
Except that the thermoplastic resin was replaced by a polyester emulsion (number average molecular weight: 16500, Tg: 16 ° C.), laminated sheet No. The same preparation as in Laminate Sheet No. 1 was performed. 3 was obtained.
[0235]
The laminate sheet No. used in Example 1 was used. No. 1 in place of the laminate sheet No. 3, and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0236]
<Example 9>
20 parts of polyester (number average molecular weight: 22000, Tg: 45 ° C.) as a thermoplastic resin, 5 parts of lanolin wax (melting point: 64 ° C.) as a release agent, and 60 parts of toluene on a transparent substrate made of PET having a thickness of 100 μm. , And 15 parts of MEK as a coating liquid, and the mixture was applied by a bar code method and dried at 100 ° C. for 10 minutes to obtain a coating film having a dry thickness of 15 μm, thereby forming a toner receiving layer. Further, a coating solution composed of PQ-50B (manufactured by Soken Kagaku) and isopropyl alcohol having a solid concentration of about 2% is applied to the surface thereon, and dried to obtain a surface resistivity of about 1.2 × 10 5¹⁰Adjusted to Ω (20 ° C., 60% RH), a laminate sheet 4 was obtained.
[0237]
The laminate sheet No. used in Example 1 was used. No. 1 in place of Laminate No. 1 4 and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0238]
<Example 10>
Ester compoundOf the cyan toner No. of Example 1 except that the amount of the toner was 7 parts by weight. No. 1 in the same manner as in the production of No. 1. 4 was produced. The cyan toner No. used in Example 1 1 in place of cyan toner No. 1 4, and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0239]
<Example 11>
Ester compoundOf the cyan toner No. of Example 1 except that the used amount was 85 parts by weight. No. 1 in the same manner as in the production of No. 1. 5 was produced. The cyan toner No. used in Example 1 1 in place of cyan toner No. 1 5, and image formation and evaluation were performed in the same manner as in Example 1. Table 2 shows the evaluation results.
[0240]
<Comparative Example 1>
In Example 1, the cyan toner No. In the production of 1, the esterCompoundIs replaced with a paraffin-based low softening point substance, and cyan toner No. 1 is used except that divinylbenzene as a crosslinking agent is not used. Table 3 shows the results in the same manner as in the manufacture of No. 1.SushiAntner No. 6 was produced. The obtained cyan toner No. FIG. 5 shows a graph of the viscoelastic properties (storage modulus G ′, loss modulus G ″, and tan (δ)) of Table 6, and Table 3 shows the values of the storage modulus G ′ at each temperature.
[0241]
The cyan toner No. used in Example 1 1 in place of cyan toner No. 1 6, and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0242]
<Comparative Example 2>
In Example 1, the cyan toner No. In the production of 1, the esterCompoundWas replaced with a paraffin-based low softening point substance in the same manner as in Example 1 except that cyan toner No. 3 shown in Table 3 was used. 7 was produced. The cyan toner No. used in Example 1 1 in place of cyan toner No. 1 7 and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0243]
<Comparative Example 3>
Except that the release agent was changed to polyethylene wax emulsion (melting point: 124 ° C.), laminated sheet No. In the same manner as in the case of Laminate Sheet No. 1, 5 was obtained.
[0244]
The laminate sheet No. used in Example 1 was used. No. 1 in place of the laminate sheet No. 5, and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0245]
<Comparative Example 4>
Laminated sheet No. 1 was replaced with a polyester emulsion (number average molecular weight: 51000, Tg: 70 ° C.). In the same manner as in the case of Laminate Sheet No. 1, 6 was obtained.
[0246]
The laminate sheet No. used in Example 1 was used. No. 1 in place of the laminate sheet No. 6 and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0247]
<Comparative Example 5>
Except that the thermoplastic resin was replaced by a polyester emulsion (number average molecular weight: 20,000, Tg: -20 ° C.), laminated sheet No. In the same manner as in the case of Laminate Sheet No. 1, 7 was obtained.
[0248]
The laminate sheet No. used in Example 1 was used. No. 1 in place of the laminate sheet No. 7 and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0249]
<Comparative Example 6>
The cyan toner No. 1 of Comparative Example 1 was used except that a yellow colorant (CI Pigment Yellow 17) was used as the colorant. 6 in the same manner as in the production of Yellow Toner No. 6 shown in Table 3. 2 was produced.
[0250]
The cyan toner No. used in Example 1 No. 1 in place of Yellow Toner No. 2, and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0251]
<Comparative Example 7>
As in Comparative Example 1, except that a magenta colorant (CI Pigment Red 122) was used as the colorant. The magenta toner at this time is No. 2, and the physical properties are shown in Table 3. Table 4 shows the evaluation results.
[0252]
<Comparative Example 8>
Except for using a black colorant (carbon black) as the colorant, the same procedure as in Comparative Example 1 was carried out. 2 is manufactured.
[0253]
No. as cyan toner No. 6 as yellow toner. No. 2 as magenta toner No. 2 as black toner. Image formation and evaluation were performed in the same manner as in Example 4 except that Sample No. 2 was used. Table 6 shows the evaluation results.
[0254]
<Comparative Example 9>
Except for using a yellow colorant (CI Pigment Yellow 17) as the colorant, the cyan toner No. 1 of Comparative Example 2 was used. 7 in the same manner as in the production of Yellow Toner 7 shown in Table 3. 3 was produced.
[0255]
Cyan toner No. 1 used in Example 1 No. 1 in place of Yellow Toner No. 3, and image formation and evaluation were performed in the same manner as in Example 1. Table 4 shows the evaluation results.
[0256]
<Comparative Example 10>
The same as Comparative Example 2 except that a magenta colorant (CI Pigment Red 122) was used as the colorant. The magenta toner at this time is No. 3, and the physical properties are shown in Table 3. Table 4 shows the evaluation results.
[0257]
<Comparative Example 11>
Except for using a black colorant (carbon black) as the colorant, the same procedure as in Comparative Example 2 was carried out. 3 is manufactured.
[0258]
No. as cyan toner No. 7 as yellow toner. No. 3 as magenta toner. No. 3 as black toner. Image formation and evaluation were performed in the same manner as in Example 4 except that Sample No. 3 was used. Table 6 shows the evaluation results.
[0259]
<Comparative Example 12>
The laminate sheet was designated as laminate sheet No. Image formation and evaluation were carried out in the same manner as in Example 4 except that Example 5 was used. Table 6 shows the evaluation results.
[0260]
[Table 1]

[0261]
[Table 2]

[0262]
[Table 3]

[0263]
[Table 4]

[0264]
[Table 5]

[0265]
[Table 6]

[0266]
【The invention's effect】
According to the present invention, a large number of color images having good color tone reproducibility can be formed without dulling at the initial stage and in the endurance even in the halftone portion of the color image projected by the OHP.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a configuration of a laminated (laminated) sheet used in the present invention.
FIG. 2 shows a heating and pressing fixing means that can be used in the heating and pressing method of the present invention.
FIG. 3 shows another example of the heating and pressing fixing means that can be used in the heating and pressing method of the present invention.
FIG. 4 shows curves of storage elastic modulus, loss elastic modulus, and tan (δ) of the toner of the present invention.
FIG. 5 shows curves of storage elastic modulus, loss elastic modulus, and tan (δ) of a comparative toner.
FIG. 6 is a schematic explanatory view of an image forming apparatus capable of performing the image forming method of the present invention.
FIG. 7 is a schematic explanatory view of another image forming apparatus that can carry out the image forming method of the present invention.
[Explanation of symbols]
1 Heat fixing means
2 Fixing roller
3 pressure roller
4 heating means
5 Recording material (laminated sheet)
6 Unfixed toner image
7 Fixed toner image
A Base layer (base film)
B Toner receiving layer
P Recording material (laminated sheet)
T toner
201 Heat resistant film
202 pressure roller
203 heating element
204 oil pad

Claims (8)

In a method for forming an imaging sheet image for forming a fixed image of a toner image formed by toner on a laminated sheet having at least a base sheet and a surface coat layer containing a thermoplastic resin as a main component,
The toner has at least a binder resin, a colorant, and an ester wax containing an ester compound as main components, and has a storage elastic modulus (G′60) at a temperature of 60 ° C. and a storage elastic modulus (G′80) at a temperature of 80 ° C. (G′60 / G′80) is 80 or more, and the ratio (G′155) between the storage elastic modulus (G′155) at a temperature of 155 ° C. and the storage elastic modulus (G′190) at a temperature of 190 ° C. / G'190) is from 0.95 to 5.0 ,
The surface coating layer contains a low-softening point substance having a melting point of 40 ° C. to 120 ° C., the surface coating layer has a polyester resin, the surface resistivity of the surface coat layer is 10 ⁷ to 13 ¹³ An image forming method, comprising: The image forming method according to claim 1 , wherein the thermoplastic resin, which is a main component of the surface coat layer, has a glass transition temperature of -10 to 80C. Melting point of the low softening point material surface coating layer contains the image forming method according to claim 1 or 2, characterized in that high 10 ° C. or higher than the glass transition temperature of the thermoplastic resin of the surface coating layer . The releasability oil has a supplying pressurized NetsuKa圧means, an image forming method according to any one of claims 1 to 3, characterized in that fixing the toner image onto the imaging sheet. The binder resin of the toner is a styrene - The image forming method according to any one of claims 1 to 4 is an acrylic resins. Laminated sheet The image forming method according to any one of claims 1 to 5 having optical transparency. The image forming method according to any one of claims 1 to 6, characterized in that the ester wax of the toner is 1 to 40 parts by weight per 100 parts by weight of the binder resin. The image forming method according to any one of claims 1 to 6, characterized in that the ester wax of the toner, a binder resin 100 parts by weight per 5 to 40 parts by weight.

Images