JP3650302B2 - Red color material composition and method for producing the same - Google Patents

Description

【００７２】
〔実施例２〕（磁性体を用いた赤色色材組成物２、水系３層被覆）
（第１層シリカ膜の製膜）
（１）シリカ製膜
基体粒子として、１５ｇの球状マグネタイト粉末（平均粒径２．３μｍ）を、あらかじめ準備しておいた２６１ｍｌの前記緩衡溶液３（ｐＨ：約９．０）に入れ分散液とした。この分散液を入れた容器を、水を張った超音波洗浄機（（株）井内盛栄堂製、ＵＳ−６型）の水槽に入れ、２６ｋＨ_Z、６００Ｗの超音波浴槽中で超音波をかけながら、さらに、マグネタイト粉を含む緩衡溶液３中で撹拌しながら分散させた。これに、同じくあらかじめ用意しておいた１３９ｍｌのケイ酸ナトリウム水溶液を４０ｍｌ／分で添加し、徐々に反応分解させ、表面にシリカ膜を析出させた。
【００７３】
ケイ酸ナトリウム水溶液添加終了後、さらに２時間反応させ、未反応原料をすべて反応させた。製膜反応終了後、シリカ製膜粉を含むスラリーを十分な水でデカンテーションを繰り返し、洗浄した。洗浄後、シリカ製膜粉をバットに入れ、沈降分離し、上液を捨てた後、乾燥機で空気中で１５０℃、８時間乾燥した後、窒素雰囲気中で５００℃で３０分熱処理（焼成）して、シリカ被覆マグネタイト粉Ｂ₁を得た。
【００７４】
（第２層チタニア膜の製膜）
実施例１と同様に、緩衡溶液４および硫酸チタン水溶液を調製、準備した。
５．５ｇの上記粉体Ｂ₁に対し、１３１３ｍｌの緩衡溶液４（ｐＨ：約８．４）を用意し、その緩衡溶液４中に粉体Ｂ₁を、上記シリカ製膜時と同様に、超音波分散しながら、超音波浴槽中で十分に分散した。その後、液の温度を５０〜５５℃に保ちながら、あらかじめ用意しておいた硫酸チタン水溶液を１．８ｍｌ／分の一定速度で徐々に滴下した。
滴下初期時には、液中に固相微粒子が析出したが、基体粒子表面に固定され、またさらに、基体粒子表面に固定された固相微粒子よりも粒径の小さい超微粒子によりその表面が覆われた、シリカ／チタニア被覆マグネタイト粉Ｂ₂を得た。 この２層膜被覆粉体Ｂ₂は淡赤色であり、最大反射ピークは７２２ｎｍであり、実施例１で得られた粉体Ａ₁と同様であった。
この粉体Ｂ₂の表面は僅かに凹凸があり、部分的にチタニア粒子の凸部もみられた。
【００７５】
（第３層シリカ膜の製膜、シリカ薄膜により前記チタニア膜表面を閉じ込めた場合）
実施例１と同様に、緩衡溶液１、２およびケイ酸ナトリウム水溶液（水ガラス溶液）の調製を行った。
上記粉体シリカ／チタニア被覆マグネタイト粉Ｂ₂１５gにシリカ膜の製膜を行った。緩衝溶液量は上記第１層被覆と同様であったが、ケイ酸ナトリウム水溶液の滴下速度は同じにして滴下量を２６１ｍｌとして製膜を行い、未反応物がなくなるまで、２時間反応させ、前記と同様に洗浄し、洗浄後、回転式チューブ炉で、窒素雰囲気中で５００℃で３０分加熱処理（焼成）を行い、シリカ／チタニア被覆マグネタイト粉Ｂ₃を得た。
【００７６】
得られた粉体Ｂ₃は、表面が平滑なシリカ膜２層の間に、チタニア微粒子が結晶化し、光散乱が大きい淡赤色の粉体となった。Ｂ₃の表面は、凹凸がなくなり、ほぼ平滑で、また穴や割れ、くぼみ等はなかった。
透過電子顕微鏡での観察において、シリカ層２層の間に、チタニア微粒子の結晶化が認められ、粒子間に空隙が存在していたため、粒子と空隙の間で散乱反射が大きくなったものと考えられる。
この３層膜被覆粉体Ｂ₃の最大反射ピークは７２３ｎｍであった。
【００７７】
（接着樹脂層、ポリスチレン複合粉体）
スチレンモノマー１００ｇにあらかじめ前記の表面処理方法で親油化した赤色色材多層被覆粉体Ｂ_３、１００ｇと同じく親油化した酸化チタン１０ｇを分散するまで高速攪拌機で攪拌し、均一化した。
このスチレンモノマーと粒子の混合物を、ｎ−ドデシル硫酸ナトリウムを蒸留水５００ｇに溶解した溶液を７０℃に温度を保持し、高速攪拌しながら投入し、十分に乳化粒子を微粒子化するまで攪拌した。
これに１０％過硫酸アンモニウム水溶液１０ｇを添加し、４時間攪拌して反応させた。
反応終了後、蒸留水２リットルで希釈し、傾斜洗浄で上液を捨て沈澱物を集める。沈澱物をろ紙上で乾燥し、赤色のポリスチレン被覆粉体Ｂを得た。
得られた赤色色材組成物Ｂの粉体は球状で、磁場１ｋＯｅでの磁化は１５ｅｍｕ／ｇであった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表２に示す。
【００７８】
【表２】

【００７９】
〔実施例３〕（磁性体を用いた赤色色材組成物３、散乱粒子を表面に付着した場合、水系４層被覆）
（第１層シリカ膜の製膜）
基体粒子として、４０ｇのマグネタイト粉（平均粒径０．７μｍ）を、実施例１と同様に、あらかじめ準備しておいた３１２６ｇの緩衡溶液３（ｐＨ：約９．０）と純水２６０ｍｌの混合液に入れ分散液とし、２８ｋＨ_Z、６００Ｗの超音波浴槽中で超音波をかけながら、さらに、マグネタイト粉を含む緩衡溶液３中で撹拌しながら分散させた。これに、同じくあらかじめ用意しておいた１３０２ｍｌのケイ酸ナトリウム水溶液を２．６７ｍｌ／分で徐々に添加し、表面にシリカ膜を析出させた。
ケイ酸ナトリウム水溶液添加終了後、さらに２時間反応させ、未反応原料をすべて反応させた。
製膜反応終了後、シリカ製膜粉を含むスラリーを十分な水でデカンテーションを繰り返し、洗浄した。
洗浄後、シリカ製膜粉をバットに入れ、沈降分離し、上液を捨てた後、乾燥機で空気中で１５０℃、８時間乾燥し、シリカ被覆マグネタイト粉Ｃ₁を得た。
【００８０】
（第２層チタニア膜の製膜）
４０ｇの上記粉体Ｃ₁に対し、５２１０ｇの緩衡溶液４と純水５２１０ｍｌを用意し、その混合液中にＣ₁を、上記シリカ製膜時と同様に、超音波分散しながら、超音波浴槽中で十分に分散した。その後、液の温度を５０〜５５℃に保ちながら、あらかじめ用意しておいた、２１１０ｍｌの硫酸チタニル水溶液（ＴｉＯ₂、１５ｗ％）を１．２５ｍｌ／分の一定速度で徐々に滴下し、液を僅かに白濁させながら滴下を終了させた。
滴下終了後、さらに３時間反応を行い、未反応分を徐々に析出させ、その粒子を膜の中に取り込んだ。
製膜反応終了後、十分な純水でデカンテーションを繰り返し、未反応分と過剰硫酸および反応により形成された硫酸を除き、固液分離を行い、真空乾燥機で乾燥後、乾燥粉を得た。
得られた乾燥粉を、回転式チューブ炉で、６５０℃で３０分加熱処理（焼成）を行い、シリカ／チタニア被覆マグネタイト粉Ｃ₂を得た。
この２層膜被覆粉体Ｃ₂は帯黄赤色であり、最大反射ピークは６０７ｎｍであった。
【００８１】
（第３層シリカ膜の製膜）
４０ｇのシリカ／チタニア被覆マグネタイト粉Ｃ₂に対し、１層目と同様に、あらかじめ準備しておいた３７５１ｇの緩衡溶液３（ｐＨ：約９．０）と純水３１３ｍｌを入れ、２８ｋＨ_Z、６００Ｗの超音波浴槽中で超音波をかけながら、さらに、マグネタイト粉を含む緩衡溶液３中で撹拌しながら分散させた。これに、同じくあらかじめ用意しておいた１５６３ｍｌのケイ酸ナトリウム水溶液を２．６７ｍｌ／分で徐々に添加し、表面にシリカ膜を析出させた。
ケイ酸ナトリウム水溶液添加終了後、さらに２時間反応させ、未反応原料をすべて反応させた。
製膜反応終了後、シリカ製膜粉を含むスラリーを十分な水でデカンテーションを繰り返し、洗浄した。
洗浄後、シリカ製膜粉をバットに入れ、沈降分離し、上液を捨てた後、乾燥機で空気中で１５０℃、８時間乾燥し、シリカ被覆マグネタイト粉Ｃ₃を得た。
【００８２】
（第４層チタニア膜の製膜）
４０ｇの上記粉体Ｃ₃に対し、３７５１ｍｌの緩衡溶液４と３１３ｍｌの純水を用意し、その混合液中に粉体Ｃ₃を、上記シリカ製膜時と同様に、超音波分散しながら、超音波浴槽中で十分に分散した。その後、液の温度を５０〜５５℃に保ちながら、あらかじめ用意しておいた、１５６３ｍｌの硫酸チタニル水溶液（ＴｉＯ₂、１５ｗ％）を１．２５ｍｌ／分の一定速度で徐々に滴下し、固相微粒子を析出させ液を僅かに白濁させながら滴下を終了させた。
滴下終了後、さらに３時間反応を行い、未反応分を徐々に固相微粒子として析出させ、その微粒子を膜の中に取り込んだ。
製膜反応終了後、十分な純水でデカンテーションを繰り返し、未反応分と過剰硫酸および反応により形成された硫酸を除き、固液分離を行い、真空乾燥機で乾燥後、乾燥粉を得た。
【００８３】
得られた乾燥粉を、回転式チューブ炉で、６５０℃で３０分加熱処理（焼成）を行い、シリカ／チタニア被覆マグネタイト粉Ｃ₄を得た。
この４層膜被覆粉体Ｃ₄ は淡赤色であり、最大反射ピークは７１８ｎｍであった。
【００８４】
（赤色インキ組成物の調製）
このようにして得られたシリカ／チタニア被覆マグネタイト粉Ｃ₄、３０ｇを、あらかじめエタノール８０ｇにアクリルポリマー（テクノビット、Ｋｕｌｚｅｒ社製）２．５ｇを溶解した溶液中に分散した後、酸化チタン（シリコン疎水処理品：展色材）２０ｇおよびヒドロキシプロピルセルロース３．２ｇを加えた混合液を、ジルコニアボールミルで８時間分散処理を行い、赤色色材組成物の塗料分散液ＣＬを得た。
【００８５】
（塗布および分光特性）
上記蛍光顔料組成物の分散液ＣＬを、ブレードコーターでアート紙に塗布した。赤色色材組成物の塗布量（乾燥後）は６０ｇ／ｍ²とした。
乾燥後、得られた塗布紙Ｃの色は最大反射ピーク波長７１８ｎｍで、反射率６７％の明るい赤色となった。また、この塗布祇Ｃの１ｍ²当たりの１ｋＯｅでの磁化は７２０ｅｍｕ／ｃｍ²であった。
上記第１〜４層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表３に示す。
【００８６】
【表３】

【００８７】
〔実施例４〕（磁性体を用いた赤色色材組成物４、金属アルコキシドの加水分解による３層被覆）
（第１層シリカ膜の製膜）
２０ｇのＢＡＳＦ製カーボニル鉄粉（平均粒径１．８μｍ，１０kOeでの磁化は２０３emu/g）を、あらかじめ１５８．６ｇのエタノールに２２．８ｇのシリコンエトキシドを溶解した溶液中で分散した後、攪拌しながら、あらかじめ用意しておいた２２．８ｇのアンモニア水（２９％）および３０．４ｇの脱イオン水の混合溶液を添加した。添加後、５時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥した。乾燥後、回転式チューブ炉を用いて、窒素雰囲気中で８００℃で３０分熱処理（焼成）を施し、冷却し、シリカコート鉄粉Ｄ₁を得た。
【００８８】
（第２層チタニア膜の製膜）
セパラブルフラスコ中で、２０ｇの上記シリカコート粉体Ｄ₁を、あらかじめ１９８．３ｇのエタノールに１７．９ｇのチタンイソプロポキシドを加えた液中に分散した後、攪拌しながら、あらかじめ用意しておいた３０．４ｇの純水を４７．９ｇのエタノールに混合した溶液を１時間かけて、滴下した。滴下後、５時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥し，シリカ／チタニアコート鉄粉Ｄ₂を得た。
乾燥後のチタニア層を透過電子顕微鏡を用いて層内の粒子状態を観察したところ、１〜１０ｎｍの酸化チタン固相微粒子がみられたが、膜の内部には粒子間の空隙はなく均一に充填されていた。
この酸化チタン膜の平均膜厚は９３ｎｍであり、７５０ｎｍに分光反射曲線のピーク波長を有し、淡赤色であった。
【００８９】
（第３層シリカ膜の製膜）
２０ｇのシリカ／チタニアコート鉄粉Ｄ₂を、あらかじめ１５６．８ｇのエタノールに３．０ｇのシリコンエトキシドを溶解した溶液中で分散した後、攪拌しながら、あらかじめ用意しておいた３．０ｇのアンモニア水（２９％）および ４．０ｇの脱イオン水の混合溶液を添加した。添加後、１時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥した。乾燥後、更に窒素雰囲気中で５００℃で３０分熱処理（焼成）を施し、冷却し、シリカ／チタニアコート鉄粉Ｄ₃を得た。
熱処理後のチタニア層を透過電子顕微鏡を用いて層内の粒子状態を観察したところ、１０〜１５０ｎｍの酸化チタン結晶化微粒子がみられ、それぞれの粒子間には１０〜５０ｎｍ程度の空隙が認められた。
しかし、シリカ層は緻密であり、粒子はなく、また平滑であった。さらに、チタニアとの界面には、空隙が存在していた。
【００９０】
この粉体Ｄ₃の最大反射ピーク波長は７７０ｎｍで、磁場１ｋＯｅでの磁化は１２９ｅｍｕ／ｇであり、淡い赤色となった。
この実施例４から、熱処理（焼成）の有無によりチタニア粒子の結晶粒子化と、粒子化に伴う粒子間およびシリカ膜との間の空隙が見られ、これらの粒子化にともなう散乱反射効果により、赤色化が達成されたと考えられる。
また、この実施例４の赤色色材粉体は最終被覆層に緻密な膜を形成することが特徴の一つである。これまでの最終層のように高屈折率膜という限定でなく、干渉、散乱に影響のない緻密な膜で空隙を被覆する。従来技術では、得られた粉体をトナーや塗料等の顔料として用いる際に、空隙に樹脂やビヒクルが入り込み、干渉あるいは散乱粒子との屈折率の差が小さくなり、フレネル反射率が低下することがあった。しかし、最終層を干渉、散乱に影響のない緻密な膜として、粒子構成膜の空隙を被覆することにより、上記散乱反射の低下を防ぐことができる。
【００９１】
（接着樹脂層、ポリスチレン複合粉体）
スチレンモノマー１００ｇに赤色色材多層被覆粉体（シリカ／チタニアコート鉄粉Ｄ₃）１００ｇと前記親油化した酸化チタン１０ｇを分散するまで高速攪拌機で攪拌し、均一化した。
このスチレンモノマーと粒子の混合物を、ｎ−ドデシル硫酸ナトリウムを蒸留水５００ｇに溶解した溶液を７０℃に温度を保持し、高速攪拌しながら投入し、十分に乳化粒子を微粒子化するまで攪拌した。
これに１０％過硫酸アンモニウム水溶液１０ｇを添加し、４時間攪拌して反応させた。
反応終了後、蒸留水２リットルで希釈し、傾斜洗浄で上液を捨て沈澱物を集める。沈澱物をろ紙上で乾燥し、赤色のポリスチレン被覆粉体Ｄを得た。
得られた赤色色材組成物Ｄの粉体は球状で、磁場１ｋＯｅでの磁化は１８．５ｅｍｕ／ｇであり、磁場１０ｋＯｅでの磁化は６１．５ｅｍｕ／ｇであった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表４に示す。
【００９２】
【表４】

【００９３】
〔実施例５〕（磁性体を用いた赤色色材組成物５、金属アルコキシドの加水分解による５層被覆）
（第１層シリカ膜の製膜）
２０ｇのＢＡＳＦ製カーボニル鉄粉（平均粒径１．８μｍ，１０ｋＯｅでの磁化は２０３ｅｍｕ／ｇ）を、あらかじめ１５８．６ｇのエタノールに１６．１ｇのシリコンエトキシドを溶解した溶液中で分散した後、攪拌しながら、あらかじめ用意しておいた１６．１ｇのアンモニア水（２９％）および１６．１ｇの脱イオン水の混合溶液を添加した。添加後、５時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥した。乾燥後、さらに回転式チューブ炉を用いて、窒素雰囲気中で６００℃で３０分熱処理（焼成）を施し、冷却し、シリカコート鉄粉Ｅ₁を得た。
【００９４】
（第２層チタニア膜の製膜）
セパラブルフラスコ中で、２０ｇの上記シリカコート粉体Ｅ₁を、あらかじめ１９８．３ｇのエタノールに１７．９ｇのチタンイソプロポキシドを加えた液中に分散した後、攪拌しながら、あらかじめ用意しておいた３１．０ｇの純水を４７．９ｇのエタノールに混合した溶液を１時間かけて、滴下した。滴下後、３時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１００℃、８時間乾燥し、シリカ／チタニアコート鉄粉Ｅ₂を得た。
この酸化チタン膜の平均膜厚は９６ｎｍであり、７６０ｎｍに分光反射曲線のピーク波長を有し、帯黄赤色であった。
【００９５】
（第３層シリカ膜の製膜）
２０ｇのシリカ／チタニアコート鉄粉Ｅ₂を、あらかじめ１５８．６ｇのエタノールに２９．７ｇのシリコンエトキシドを溶解した溶液中で分散した後、攪拌しながら、あらかじめ用意しておいた２９．７ｇのアンモニア水（２９％）および３９．６ｇの脱イオン水の混合溶液を添加した。添加後、５時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥した。乾燥後、さらに回転式チューブ炉を用いて、窒素雰囲気中で５００℃で３０分熱処理（焼成）を施し、冷却し、シリカ／チタニアコート鉄粉Ｅ₃を得た。
【００９６】
（第４層チタニア膜の製膜）
セパラブルフラスコ中で、２０ｇの上記シリカコート粉体Ｅ₃を、あらかじめ１９８．３ｇのエタノールに２３．２ｇのチタンイソプロポキシドを加えた液中に分散した後、攪拌しながら、あらかじめ用意しておいた３９．６ｇの純水を６０．０ｇのエタノールに混合した溶液を１時間かけて、滴下した。滴下後、４時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１００℃、８時間乾燥し、シリカ／チタニアコート鉄粉Ｅ₄を得た。
【００９７】
（第５層シリカ膜の製膜）
２０ｇのシリカ／チタニアコート鉄粉Ｅ₄を、あらかじめ１５８．６ｇのエタノールに２．５ｇのシリコンエトキシドを溶解した溶液中で分散した後、攪拌しながら、あらかじめ用意しておいた２．５ｇのアンモニア水（２９％）および３．０ｇの脱イオン水の混合溶液を添加した。添加後、５時間、常温で反応させた。反応後、十分なエタノールで希釈洗浄し、濾過し、真空乾燥機で１１０℃、３時間乾燥した。乾燥後、さらに回転式チューブ炉を用いて、窒素雰囲気中で６００℃で３０分熱処理（熱処理）を施し、冷却し、シリカ／チタニアコート鉄粉Ｅ₅を得た。
この鉄粉Ｅ₅は７６０ｎｍに分光反射曲線のピーク波長を有し、淡赤色であった。磁場１０ｋＯｅでの磁化は８２ｅｍｕ／ｇであった。
【００９８】
（赤色インキ組成物の調製）
このようにして得られたシリカ／チタニアコート鉄粉Ｅ₅、３０ｇを、あらかじめエタノール８０ｇにアクリルポリマー（テクノビット、Ｋｕｌｚｅｒ社製）２．５ｇを溶解した溶液中に分散した後、酸化チタン（シリコン疎水処理品：展色材）２０ｇおよびヒドロキシプロピルセルロース３．２ｇを加えた混合液を、ジルコニアボールミルで８時間分散処理を行い、赤色色材組成物の塗料分散液ＥＬを得た。
【００９９】
（塗布および分光特性）
上記蛍光顔料組成物の分散液ＥＬを、ブレードコーターでアート紙に塗布した。赤色色材組成物の塗布量（乾燥後）は６０ｇ／ｍ²とした。
乾燥後、得られた塗布紙Ｅの色はピーク波長で７５５ｎｍであり、明るい赤色となった。
また、この塗布祇Ｅの磁場１ｋＯｅでの磁化は１４８０ｅｍｕ／ｍ²であり、磁場１０ｋＯｅでの磁化は４９２０ｅｍｕ／ｍ²であった。
上記第１〜５層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表５に示す。
【０１００】
【表５】

【０１０１】
〔実施例６〕（乾式被膜磁性体を用いた赤色色材組成物６、水系３層被覆）
（第１層チタニア膜の製膜）
平均粒径１．８ミクロンの鉄粉１ｋｇと平均粒径０．２ミクロンの酸化チタン粒子１．５ｋｇをホソカワミクロン製メカノフュージョン装置を用いて５分間、３回乾式混 合粉砕し、膜が形成されたのを確認し、明度が向上した酸化チタン被覆鉄粉をＦ₁を得た。
【０１０２】
（第２層シリカ膜の製膜）
予め用意した実施例１と同様の緩衝溶液３，２１４ｍｌに対し、同じく予め用意した純水、１８１ｍｌを混合し、Ｆ₁、１０ｇを添加し十分に混合した後、ＳｉＯ₂の混合率１０wt％の水ガラス溶液 １４５ｍｌを撹拌しながら徐々に３時間かけて滴下撹拌した後、１時間反応を継続させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ／チタニア膜被覆鉄粉Ｆ₂を得た。
【０１０３】
（第３層チタニア膜の製膜）
さらにシリカ／チタニア膜被覆鉄粉Ｆ₂、４ｇに対し、緩衝液４，４８４ mlを加え十分に分散させた後、硫酸チタニルのＴｉＯ₂１５％水溶液、３８ ｍｌを４時間かけて滴下し、滴下後、１時間反応させ、未反応原料を無くした。反応後デカンテーションにより固液分離し、粉体を真空乾燥機で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ／チタニア膜 被覆鉄粉Ｆ₃を得た。
この粉体のピークは７２８ｎｍで反射率は４４％であり、濃い赤色であった。またこの粉体の磁場１ｋＯｅの磁化は３１．４ｅｍｕ／ｇで、１０ｋＯｅの磁化は９８４ｅｍｕ／ｇであった。
【０１０４】
（トナー化）
スチレンモノマー１００ｇキシレン３０ｍｌに０．３ｇのオイルレッドを溶解した液を混合した後、予め得られたＦ₃粉を親油化したもの１００ｇと、酸化チタン１０ｇを加え均一に混合した。
次に、このスチレンモノマーと粒子の混合物を、ドデシル硫酸ナトリウム３ｇを溶解した水溶液に投入した後、ホモジナイザーで１０，０００ｒｐｍで撹拌し、さらに、５，０００ｒｐｍで撹拌しながら７０℃に温度を保持した後、１０％過硫酸アンモニウム水溶液１０ｇを添加し、３.５時間反応させた。
その後、固形分を濾過し、温水で３回繰り返し洗浄を行い、赤色のポリスチレン被覆粉体ＦＰを得た。この粉体の１ｋＯｅでの磁場磁化は１８．６４ｅｍｕ／ｇであり、１０ｋＯｅでの磁化は４６．７４ｅｍｕ／ｇとなった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表６に示す。
【０１０５】
【表６】

【０１０６】
〔実施例７〕（板磁性体を用いた青色色材組成物７、金属アルコキシド加水分解および水系による３層被覆）（インキ）
（第１層シリカ膜の製膜）
平均粒径２．８ミクロンの板状Ｂａ系フェライト１０ｇに対し、エタノール７９．５ｇを加え十 分に分散した後、シリコンエトキシド１１．４ｇを添加し混合し、さらに、水１１．２ｇ、アンモニア水１５．２ｇを添加して、常温で撹拌しながら、３時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ膜被覆Ｂａ系フェライト粒子Ｇ₁を得た。
【０１０７】
（第２層チタン膜被覆着色）
シリカ膜被覆Ｂａ系フェライト粒子Ｇ₁、１０ｇをエタノール１５９ｇに十分分散した後チタンイソプロポキシド８．９gを添加し、十分に混合した後、さらに予め用意しておいた水１５．２ｇ、エタノール３０ｇの混合溶液を滴下し５時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で６５０℃で３０分熱処理し、シリカ／チタニア膜被覆Ｂａ系フェライト粒子Ｇ₂を得た。
この粉体のピークは７８０ｎｍで反射率は42％であり、濃い赤色であった。またこの粉体の１０ｋＯｅの磁化は１３．６ｅｍｕ／ｇであり、残留磁化は８．６ｅｍｕ／ｇであった。
【０１０８】
（第３層散乱膜被覆）
予め用意したＧ₂粉１０gに対し、同じく予め用意した緩衝溶液４を８７５ ｍｌ混合し、これに平均粒径０．２ミクロンの酸化チタン（ルチル型）粉体粒子５ｇを添加し十分に混合した後、１０ｗｔ％の水ガラス溶液２７４ｍｌ撹拌しながら１時間撹拌した。デカンテーションを２０回繰り返し十分に洗浄したあと、乾燥機で１２０℃で８時間乾燥した。乾燥後の粉体を回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ膜／チタニア散乱膜被覆Ｂａ系フェライト粒子Ｇ₃を得た。
この粉体のピークは７８０ｎｍで反射率は６７％、淡い青色であった。
またこの粉体の１０ｋＯｅの磁化は１０．０ｅｍｕ／ｇであり、残留磁化は６．６ｅｍｕ／ｇであった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表７に示す。
【０１０９】
【表７】

【０１１０】
（インキ化）
上記Ｇ₃粉３０gに対し、あらかじめアクリル樹脂１.５gとヒドロキシプロピルセルロース２.３gを、エタノール溶液８０gに分散し、撹拌しながらアルコールを蒸発させ粘度を上昇させた液体ＧＬを得た。
このＧＬを理想科学製小形印刷機ＰＧ１０で、熱転写用プラスチック製フィルムに縞模様を形成した。
【０１１１】
（塗布物）
乾燥後磁気ヘッドを具備した検出装置で、このフィルム上を走査したところ、本磁気粉体Ｇ_３の印刷された部分では磁気反応が検出されたが、空白部分では磁気反応は出なかった。また塗布物は上方から見ると赤色であったが、角度３０度の斜めから見た場合は、黄色に見え多色性がみられた。
【０１１２】
〔実施例８〕（板状鉱物を用いた赤色色材組成物８、金属アルコキシド加水分解による３層被覆）（塗膜）
（第１層被覆着色）
平均粒径１２ミクロンの板状白雲母粉２０ｇをエタノール１６０ｇに十分分散した後チタンイソプロポキシドを９g添加し、十分に混合した後、さらに予め用意しておいた水１５．５ｇ、エタノール３０ｇの混合溶液を滴下し５時間反応させた。反応後デカンテーションにより固液分離し、粉体を空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、チタニア膜被覆板状白雲母粉Ｈ₁を得た。
この粉体のピークは７８５ｎｍで反射率は４２％であり、濃い赤色であった。
【０１１３】
（第２層被覆）
チタニア被覆板状白雲母粉Ｈ₁、２０ｇをエタノール８０ｇに十分に分散した後、シリコンエトキシド１５．１ｇを添加し混合し、さらに、水１９．９ｇ、アンモニア水１５．１ｇを添加して、常温で撹拌しながら、３時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ／チタニア被覆板状白雲母粉Ｈ₂を得た。
【０１１４】
（第３層着色膜被覆）
シリカ／チタニア被覆板状白雲母粉Ｈ₂、２０ｇをエタノール160ｇに十分分散した後チタンイソプロポキシド１５．１gを添加し、十分に混合した後、さらに予め用意しておいた水１５．１ｇ、エタノール30ｇの混合溶液を滴下し５時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ／チタニア膜被覆板状白雲母粉Ｈ₃を得た。
この粉体のピークは７８５ｎｍで反射率は６５％、淡い赤色であった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表８に示す。
【０１１５】
【表８】

【０１１６】
（塗布）
上記粉Ｈ₃、１５ｇを撹拌、分散しながらアクリル樹脂２．２ｇを溶解したエタノール溶液（エタノール５０ｇ）を入れ溶解した。
溶媒の一部が分散し粘度が上昇したところで、分散液を平板ガラス板に伸ばしさらにゴムローラーに均一に付着させた後、Ａ４版の熱転写用フィルムに、粘性流体ＨＬを塗布し１日放置し乾燥した。
得られた粉体塗布フィルムは垂直に見ると淡赤色の帯がみられ、さらに、板を太陽に向け傾けて見る角度変えると、太陽を背にした場合（ほぼ垂直光）では淡い赤色であったが、太陽と板の角度（入射角）が板から４０度になるように見た場合その色は黄色を帯び、多色性が認められた。
この性質は多色性表示媒体、化粧品や装飾品あるいはフリップフロップ法に用いることができる。
【０１１７】
〔実施例９〕（板状導電体を用いた赤色色材組成物９、金属アルコキシド加水分解による３層被覆）（塗料）
（第１層被覆着色）
平均粒径１２ミクロンの板状アルミニウム粉１８ｇをエタノール１６０ｇに十分分散した後チタンイソプロポキシド９．０gを添加し、十分に混合した後、さらに予め用意しておいた水１５．５ｇ、エタノール１６０ｇの混合溶液を滴下し５時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、チタニア膜被覆板状アルミニウム粉Ｉ₁を得た。
この粉体のピークは７８０nmで反射率は４２％であり、濃い赤色であった。
【０１１８】
（第２層被覆）
チタニア被覆板状アルミニウム粉Ｉ₁、１８ｇをエタノール１５．１ｇに十分に分散した後、シリコンエトキシド８.1ｇを添加し混合し、さらに、水１９．９ｇ、アンモニア水１５．１ｇを添加して、常温で撹拌しながら、３時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、シリカ／チタニア被覆板状アルミニウム粉Ｉ₂を得た。
【０１１９】
（第３層着色膜被覆）
シリカ／チタニア被覆板状アルミニウム粉Ｉ₂、１８ｇをエタノール１６０ｇに十分分散した後チタンイソプロポキシド１１．８ｇを添加し、十分に混合した後、さらに予め用意しておいた水２０．１ｇ、エタノール１６０ｇの混合溶液を滴下し ５時間反応させた。反応後デカンテーションにより固液分離し、粉体を真空乾燥後で８時間乾燥後、回転式チューブ炉を用い、窒素雰囲気で５００℃で３０分熱処理し、チタニア／シリカ膜被覆板状アルミニウム粉Ｉ₃を得た。
この粉体のピークは７８５ｎｍで反射率は６８％、淡い赤色であった。
上記第１〜３層の各屈折率、膜厚、被覆粉体の分光反射曲線のピーク波長およびそのピーク波長での反射率を表９に示す。
【０１２０】
【表９】

【０１２１】
（塗布）
長辺８０ｍｍ，単辺５７ｍｍ，厚さ1.5ｍｍ白色塩化ビニル板に両面粘着テープを幅３ｍｍ、長さ５７ｍｍの帯状にしたものを７本用意し、板状の単辺に平行に中心に１枚貼った後、中心の帯状テープから３ｍｍ間隔で平行に貼り付けた。その後、Ｉ₃をこのテープが貼られた板に均一になるよう降りかけた。さらにこの白色塩化ビニル板を水平においた一辺１０cｍ、厚さ１ｃｍの鉄板の上に置き、さらに同じ板を上に置き２枚で挟みこみ、板の中心に１ｋｇの分銅を載せ１時間放置した。
１時間後、板を取り去り、さらに付着しなかった粉を筆で払い落とした。
得られた板は垂直に見ると淡赤色の帯がみられ、実施例８と同様に多色性が認められた。
【０１２２】
（物性）
ホイートストンブリッジと電源および電流計を具備したサーチコイルを、この板の単辺に垂直に走査した結果、塗布部分では電流計に変化があったが、無い部分では変化が見られなかった。電場による検出も可能である。
この性質は多色性表示媒体、化粧品や装飾品あるいはフリップフロップ法に用いることができる。
【０１２３】
表１〜９から明らかなように、本発明の各実施例の赤色色材組成物は、それぞれ満足すべき結果を得た。また、チタニア粒子の結晶粒子化による空隙を有するチタニア被覆層は１層（第２層）よりも２層（第２層および第４層）に有することにより、高度の赤色化が達成された。
【０１２４】
【発明の効果】
以上説明したように、本発明の赤色色材組成物は、含有される赤色粉体の製造における製膜反応の際に、水を溶媒として用いることにより、アルコキシド法に比べ安価な製造コストで製膜できるという効果が得られる。
また、基体粒子の表面に有する被覆膜の少なくとも１層を、結晶化微粒子と該結晶化微粒子相互間に空隙を有する結晶化微粒子の集合体とからなる膜（以下、単に結晶化微粒子構成膜ともいう）とすることにより、結晶化粒子表面と空隙との屈折率差を大きくして、光の散乱反射を起こし、反射効果を高め、優れた明度を有する赤色色調の機能性粉体を含有する赤色色材組成物を提供することが可能となった。
【０１２５】
上記のようにして得られた本発明の赤色色材組成物は、含有される赤色粉体の基体として磁性体を活用すると、基体粒子の特性（例えば、磁気特性）を高レベルに保持した機能性粉体、例えば、１成分系現像方式でも優れた複合した機能を果たし得る赤色磁性トナーや、優れた磁気特性を発揮することができる。また、多色性や反射あるいは透過色を利用して意匠性に富んだ装飾品、陶器、磁器、ガラス器、絵画などの工芸品・美術品用、書籍、自動車・自転車などの塗料赤色多機能性インキ、トナー、塗料、化粧品ができ、さらに触媒作用を持つ酸化チタン膜等により耐候性にすぐれ大気・水などの環境浄化性のある塗料ができ、かつ基体の特性と膜の特性を兼ね備えた赤色多機能性インキ、トナーおよび塗料等に適用できる。特に前記機能が磁気、電場、色、粒子形状、蛍光発光、蓄光発光、特定紫外線域反射吸収並びに特定赤外線反射吸収の機能のいずれか２種以上を組み合わせることにより偽造防止用顔料組成物として印刷インキ、トナーとして支持媒体上に所望の画像を形成し、目視による判別、機器による判別することができる赤色色材組成物およびその効率的製造方法を提供することが可能となった。
これらの優れた機能を有すると共に、含有される赤色粉体の基体として導電体または誘電体を活用すると、電場、の外部要因により反応することにより移動力、回転、運動、発熱などの付加的な作用を発する機能を保持した赤色色材組成物およびその効率的製造方法を提供することが可能であり、産業界に寄与するところ大である。
【図面の簡単な説明】
【図１】本発明の赤色色材組成物に含有される赤色粉体の一例の断面図である。
【図２】図１の赤色色材組成物に含有される赤色粉体が有する結晶化微粒子構成膜２の断面拡大図である。
【符号の説明】
１ 基体粒子
２ 結晶化微粒子構成膜
３ 結晶化微粒子
４ 超微粒子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a red color material composition and a method for producing the same, and more specifically, it can be produced by an inexpensive and safe method without using an expensive raw material or a dangerous organic solvent.・ Paper filler, toner, ink for ink jet printer, anti-counterfeit ink / toner, general paint, automotive powder pigment / paint, electrostatic paint, cosmetics, hair decoration, pigment composition, crafts / ceramics Pigment compositions and paints for fine arts, etc., pigment compositions for polychromatic paints, pigment compositions for fiber coloring (supported), paints for toys, paints and fillers for decorative paper / decorative boards, paints for plastics and metals And red color material compositions used for various purposes such as fillers, pigment compositions for displays, paints for display media, paints for magnetic recording media, pigment compositions for catalyst paints and heat-resistant paints, etc. A method for producing the same.
[0002]
[Prior art]
In recent years, colorization of images to be handled has become common in the technical fields of electrophotography and printing, and various studies have been conducted on techniques relating to colorization.
In particular, toner in electrophotography and printing ink in printing are typical examples.
Such toner, printing ink, and the like may be collectively referred to as a color material composition.
In order to obtain a color image, among the above-described color material compositions, particularly red ones may be important. Red is one of the three primary colors of light and is an important pigment that gives people psychological warmth, vitality, passion and attention. Obtaining a color material composition having such a red color tone and a specific function is highly significant in industry.
For example, in a one-component development method in which the toner itself by electrophotography has magnetism, black magnetic toner is used in conventional monochrome copying and printing. Also in the field of printing, in order to give a printed image a magnetic identification function, a magnetic powder may be included to obtain a black magnetic ink.
However, in copying and printing a color image, it is necessary to use a magnetic toner or a magnetic ink that is colored in red or a bright primary color other than black and retains magnetic characteristics. In order to obtain a clear color image with this one-component color magnetic toner or color magnetic ink, it is necessary to color the color material composition itself such as magnetic toner or ink in vivid colors. Since the body particles are generally black, even if a pigment or dye is added directly to the color material composition or a colored layer is provided directly on the surface of the magnetic material particles, the color material composition has a dark tone as a whole. There is a problem.
[0003]
On the other hand, the present inventors previously formed a metal film on the substrate particles, and whitened the powder by the reflection effect of the film (Japanese Patent Laid-Open Nos. 3-271376 and 3). 274278), a method of producing a uniform metal oxide film having a thickness of 0.01 to 20 μm on the surface of the substrate particles by dispersing the substrate particles in a metal alkoxide solution and hydrolyzing the metal alkoxide (special feature). Kaihei 6-228604), providing a functional powder by alternately providing a plurality of thin films made of metal oxide and thin films made of metal on the surface (Japanese Patent Laid-Open No. 7-90310), metal oxide It has been proposed to produce a powder having a denser and more stable metal oxide multilayer film by heat-treating the powder formed by multilayer coating with the film (International Publication WO96 / 28269).
[0004]
In particular, the metal oxide film or the powder provided with a plurality of layers of the metal film mentioned above can be given a special function by adjusting the film thickness of each layer, for example, the surface of the base particle In addition, when coating films having different refractive indexes are provided in thicknesses corresponding to a quarter wavelength of incident light, powder that reflects all incident light can be obtained. When this is applied to a magnetic substance as a base particle, a white toner powder can be produced by reflecting light, and each unit constituting the light-interfering multilayer film on the surface of the powder. If the film thickness is set so that the coating layer has a specific interference reflection peak of the same wavelength, it is suggested that a monochromatic powder can be obtained without using a dye or a pigment.
In the methods described in JP-A-6-228604, JP-A-7-90310, and International Publication WO96 / 28269, the lightness increases as the number of films and the film thickness increase, so that the reflectance increases. The characteristic becomes remarkable. However, as the number of films and film thickness increase, the characteristics of the substrate particles decrease. For example, when magnetic powder is used as the base particles, the magnetic properties become inferior as the number of films and the film thickness increase. In other words, the colored powder obtained by the above method needs to reduce the number of films and the film thickness in order to take advantage of the characteristics of the base particles. There was also a fear that it could not be obtained.
[0005]
Based on the above technique, the present inventors develop a technique for obtaining a coloring material composition having a specific target color tone, and in particular, develop a color of a film coating powder exhibiting a bright red color. Tried to establish a range of conditions for.
As a result of studying from such a viewpoint, the present inventors have found that a plurality of coating films in which a film having a large refractive index and a film having a small refractive index are laminated next to each other on the surface of the base particle are formed on the outside of the film layer. By setting the conditions of the substrate particles and the coating film so as to show a reflection spectrum having a peak between 600 and 800 nm, the color tone of the red system is changed. It has been found that a color toner can be obtained which has a composite function even with a one-component development system (Japanese Patent Laid-Open No. 11-24319).
[0006]
[Problems to be solved by the invention]
However, the red toner described in JP-A-11-24319 is one in which the coating layer on the surface of the base particles is formed by a hydrolysis reaction of a metal alkoxide. In the method for forming a film by hydrolysis of metal alkoxide, an organic material having high flammability must be used as a solvent, and expensive metal alkoxide must be used as a raw material. In order to use a highly flammable organic solvent, the production facility is made an explosion-proof facility, and the temperature and humidity are strictly controlled, and the price of the product manufactured using it is naturally expensive.
Further, the red toner described in JP-A-11-24319 does not have sufficient lightness and has a dark color tone.
[0007]
Therefore, the object of the present invention is to overcome the above-mentioned drawbacks of the prior art, without using a method based on hydrolysis of metal alkoxides, without using expensive metal alkoxides or highly flammable organic solvents, and to prevent explosions in manufacturing facilities. Provided is a highly functional red color material composition containing a red powder and a method for producing the same, which does not require equipment, can be easily controlled in temperature and humidity, and can be obtained at a low price overall. There is.
A further object of the present invention is a red color material composition which can be used as a toner, ink or paint having a high lightness and a stable color tone, and which retains the properties (for example, magnetic properties) of the substrate particles at a high level. In order to take advantage of the characteristics of the base particles, a red color material composition based on a red powder having a coating film capable of obtaining sufficient brightness even with a relatively small number of films and film thickness, and The manufacturing method is intended to be provided.
Still another object of the present invention is a red magnetic toner that can perform an excellent combined function even in a one-component development system, and a red magnetic printing ink that can exhibit excellent magnetic properties and has excellent weather resistance. Another object of the present invention is to provide a red color material composition that can be applied to a red paint and the like and an efficient production method thereof.
[0008]
[Means for Solving the Problems]
In view of the present situation, the present inventors have conducted intensive studies, and as a result, when producing a multilayer coating powder, at least one layer of the coating film on the surface of the substrate particles is caused by a reaction of a metal salt in an aqueous solvent. Forming and combining the films, the thickness of each film, the method of controlling them and the reaction conditions (pH, dispersion conditions, etc.) Limited to range. In addition, at least one layer of the coating film is a coating film having voids made of crystallized fine particles, thereby improving brightness by scattering reflection, thereby obtaining a bright red powder. The inventors have found that the object can be achieved and have reached the present invention.
[0009]
  That is, the red color material composition of the present invention and the production method thereof are as follows.
(1) By the reaction of metal salt in the aqueous solvent on the surface of the substrate particlesIt was formed by forming solid phase microparticles in the reaction solution and incorporating the formed solid phase microparticles, and was configured as an aggregate of crystallized microparticles having voidsA red color material composition comprising a red powder having a reflection spectrum having at least one coating film and having a peak between 600 and 800 nm.
(2) The coating film formed by the reaction of the metal salt in the aqueous solvent of the red powder satisfies the following formula:(1)The red color material composition as described.
  Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient)
(3) The red color material composition as described in (1) above, wherein the coating film on the surface of the base particles of the red powder is a multilayer film.
(4) The red color material composition as described in (3) above, wherein each film of the red powder multilayer film is formed by reaction of a metal salt in an aqueous solvent.
(5) The red color material composition as described in (3) above, wherein each film of the red powder multilayer film satisfies the following formula.
  Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient)
[0010]
(6)The coating film configured as an aggregate of crystallized fine particles having voids is capable of imparting lightness by scattering and reflecting light generated between the surface of the crystallized fine particles and the voids. The red color material composition according to (1) above.
(7)The above-mentioned coating film configured as an aggregate of crystallized fine particles having voids has a dense coating film composed of ultrafine particles capable of closing the voids on the surface ( 1) The red color material composition as described.
(8)The red color material composition as described in (1) above, wherein the coating film configured as an aggregate of crystallized fine particles having voids is a high refractive index film.
(9)The red color material composition as described in (7) above, wherein the dense film is a silica film.
[0011]
(10) The red color material composition as described in (1) above, which is formed by firing solid phase fine particles in the coating film and then firing.
(11)The red color material composition as described in (1) above, wherein the reaction solution is an aqueous solution.
(12)Before the firing, the coating film into which the solid phase fine particles have been incorporated is coated with ultrafine particles that can form a dense film that closes the voids on the surface of the coating film. The red color material composition according to (10).
(13)The red color material composition according to any one of (1) to (12), wherein the red powder is dispersed in a dispersion medium containing at least a binding resin.
(14)The red color material composition according to any one of (1) to (13), wherein an adhesive resin layer is provided on the red powder.
(15)The red color material composition as described in (14) above, wherein the adhesive resin layer contains an extender pigment.
[0012]
(16) In the method for producing a red color material composition containing red powder, the surface of the base particle in an aqueous solvent is used so that the red powder exhibits a reflection spectrum having a peak between 600 and 800 nm. Formed by forming solid phase microparticles in the reaction solution by reaction of metal salt and incorporating the formed solid phase microparticles, forming at least one coating film as an aggregate of crystallized microparticles having voids A method for producing a red color material composition.
(17) The method for producing a red color material composition as described in (16) above, wherein the coating film formed by the reaction of a metal salt in an aqueous solvent is formed so as to satisfy the following formula: .
  Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient)
(18) The method for producing a red color material composition as described in (16) above, wherein the coating film formed on the surface of the substrate particles is a multilayer film.
(19)The method for producing a red color material composition as described in (18) above, wherein each film of the multilayer film is formed by reaction of a metal salt in an aqueous solvent.
(20)The method for producing a red color material composition according to (18), wherein all the films of the multilayer film are formed so as to satisfy the condition of the following formula.
  Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient)
[0013]
(21) The coating film configured as an aggregate of crystallized fine particles having voids is formed so that brightness can be imparted by light scattering and reflection generated between the surface of the crystallized fine particles and the voids. The manufacturing method of the red color material composition as described in said (16).
(22) The above-mentioned (16), characterized in that a dense film is formed on the surface of the coating film configured as an aggregate of crystallized fine particles having voids, with ultrafine particles capable of closing the voids on the surface. The manufacturing method of the red color material composition of description.
(23) The method for producing a red color material composition as described in (16) above, wherein the coating film constituting the aggregate of crystallized fine particles having voids is a high refractive index film.
(24)The method for producing a red color material composition according to (22), wherein the dense film is a silica film.
(25)The method for producing a red color material composition as described in (16) above, wherein the solid phase fine particles are formed by firing after being taken into the coating film.
[0014]
(26) The method for producing a red color material composition according to (25), wherein the reaction solution is an aqueous solution.
(27) Before performing the firing, the coating film into which the solid phase fine particles have been incorporated is coated with ultrafine particles capable of forming a dense film that closes the voids on the surface of the coating film. The method for producing a red color material composition as described in (25) above.
(28) The method for producing a red color material composition according to any one of (16) to (27), wherein the red powder is dispersed in a dispersion medium containing at least a binding resin.
(29) The method for producing a red color material composition according to any one of (16) to (28), wherein an adhesive resin layer is provided on the red powder.
(30) The method for producing a red color material composition as described in (29) above, wherein the adhesive resin layer contains an extender pigment.
[0015]
The red powder in the red color material composition of the present invention is a film having a uniform thickness on the surface of the substrate particles, by suppressing the precipitation of a solid phase that does not become a film by the following operations and actions during the film-forming reaction. Is estimated to be formed with a desired thickness. (1) By using a buffer solution as a reaction solvent and adjusting to a certain pH, the influence of acid or alkali is mitigated, and erosion of the substrate surface is prevented; and (2) substrate particles are obtained by ultrasonic dispersion. In particular, it not only improves the dispersibility of magnetic materials such as magnetite powder, but also improves the diffusibility of the coating components, and further prevents the adhesion of the coatings, and the dispersibility of the coated magnetic particles. (3) The coating components are deposited at an appropriate reaction rate, and the solid phase that does not become a coating is prevented from being deposited.
Due to the above comprehensive action, the charge on the surface of the film-coated powder can be kept constant, and the action of the electric double layer prevents the film-coated powder from agglomerating and obtains dispersed particles. In order to make use of the function of the electric double layer, the pH differs depending on the combination of the substance of the substrate and the kind of metal compound formed in the liquid by the film-forming reaction, and it is preferable to avoid the isoelectric point of both.
Further, at least one layer of the coating film on the surface of the base particle is formed of a film made of an aggregate of crystallized fine particles and crystallized fine particles having voids between the crystallized fine particles (hereinafter, simply referred to as a crystallized fine particle constituting film). By increasing the refractive index difference between the surface of the crystallized fine particles and the voids, the light scattering effect is increased, the reflection effect is enhanced, and a functional powder of red tone having excellent brightness is provided. It became possible.
[0016]
According to the present invention, the film having a film thickness that allows preferable film thickness control without aggregation or adhesion of film-coated powders even when a magnetic material is used as a substrate, even though a water-soluble raw material is used. Making it possible to easily produce coated powders
did it. In addition, it is possible to provide a functional powder that maintains the characteristics (for example, magnetic characteristics) of the base particles at a high level.
Furthermore, by using water as a solvent, it is possible to obtain an effect that a film can be formed at a lower production cost than the alkoxide method.
[0017]
The red color material composition of the present invention obtained as described above is useful as a red composite powder used as a raw material for pigments, powder metallurgy, ceramic raw materials, electronics industry, etc. In addition, it can maintain excellent performance in place of conventional pigments used in plastic and paper fillers, and can have a stable color tone even in long-term storage.
Utilizing heat resistance, it can be used for painting, design and decoration as a pigment composition for coloring ceramics, porcelain, glassware, crafts, arts and decorations.
Furthermore, it is used for decorations, ceramics, porcelain, glassware, arts and crafts such as paintings, books, cars, bicycles, etc. Ink, toner, paint, cosmetics are available.
In addition, a titanium oxide film or the like having a catalytic action can provide a paint having excellent weather resistance and environmental purification properties such as air and water.
That is, the present invention can be applied to red multifunctional inks, toners, paints, and the like that have the characteristics of these substrates and the characteristics of films.
In particular, printing inks as anti-counterfeiting pigment compositions by combining two or more of the above functions with the functions of magnetism, electric field, color, particle shape, fluorescence emission, phosphorescent emission, specific ultraviolet ray reflection absorption and specific infrared reflection absorption Further, it is possible to form a desired image on the support medium as the toner and to make a visual discrimination or a discrimination target by the device.
[0018]
Hereinafter, the crystallized fine particle constituting film of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an example of a red color material composition of the present invention having a crystallized fine particle constituting film 2 on the surface of a substrate particle 1, and FIG. 2 is a crystallization of the red color material composition of FIG. 2 is an enlarged cross-sectional view of a fine particle constituting film 2. FIG.
As shown in FIGS. 1 and 2, the crystallized fine particle constituting film 2 has voids between the crystallized fine particles 3, thereby increasing the difference in refractive index between the surface of the crystallized fine particles 3 and the voids. Thus, it is possible to obtain a powder having high brightness. The stronger the above-mentioned scattering reflection, the higher the brightness of the powder.
The crystallized fine particles 3 contained in the film 2 preferably have a high refractive index, and preferably have a uniform particle size.
The brightness can be adjusted by the amount and particle diameter of crystallized fine particles in the film.
However, depending on the particle size, scattering and interference may occur simultaneously, and the interference may exhibit a hue other than red, so care must be taken in its design.
In particular, when the obtained film-coated powder has a strong monochromatic spectral color like opal, the crystallized particle diameter in the film is uniform with a certain size (about one-quarter to one wavelength of the wavelength of light). Thus, it is considered that interference due to the crystallized fine particles occurs.
[0019]
In this case, the particle diameter of the crystallized fine particles in the film is preferably 1 to 500 nm, more preferably 1 to 200 nm, and still more preferably 1 to 100 nm. If the particle diameter is less than 1 nm, the constituent film may transmit light, and the color of the underlying substrate particles may appear as it is. On the other hand, when the thickness is larger than 500 nm, the interference coloring occurs due to the reflected light of a plurality of particles, or the film becomes brittle, so that it is not preferable because it is easily peeled off.
The crystallized fine particles in the film can be distinguished by shapes such as grain boundaries even if they are in contact with other fine particles or the film.
[0020]
On the other hand, the preferred thickness range of one layer of the crystallized fine particle constituting film varies depending on the size of the particles serving as the substrate. When the substrate particles are 0.1 μm to 1 μm, it is preferably 0.05 μm to 0.5 μm, when the substrate particles are 1 μm to 10 μm, 0.05 μm to 2 μm, and when the substrate particles are 10 μm or more, it is preferably 0.05 μm to 3 μm.
Further, the preferable thickness range of the total film thickness of the crystallized fine particle constituting film also varies depending on the size of the particles serving as the substrate. It is preferable that the base particles are 0.1 μm to 3 μm when the base particles are 0.1 μm to 1 μm, 0.1 μm to 5 μm when the base particles are 1 μm to 10 μm, and 0.1 μm to 10 μm when the base particles are 10 μm or more.
[0021]
Further, in the red color material composition of the present invention, as shown in FIG. 2, the contained red powder has voids on the surface of the film 2 composed of crystallized fine particles 3 having voids. It is preferable to have a dense coating film (hereinafter also simply referred to as a dense film) composed of ultrafine particles 4 that can be closed.
For example, when a red powder having the crystallized fine particle constituent film as the outermost layer as described above is used as a pigment powder such as toner or paint, the toner resin or the paint vehicle enters the voids and the crystallized fine particles 3 The difference in refractive index between the surface and the air gap is reduced to weaken the light scattering reflection, and as a result, the brightness is also lowered.
The above-described dense film is suitable for preventing the above-described decrease in brightness.
[0022]
In JP-A-4-269804, a colored powder having a coating layer of inorganic pigment particles on the surface is described. In this colored powder, voids between the pigment particles are formed between the surface treatment agent and the resin. It is filled with a mixture and does not generate scattering reflection like the red color material composition of the present invention, but is colored to a desired color by the color of the pigment particles themselves. In the colored powder described in JP-A-4-269804, pigment particles may not be sufficiently fixed on the surface of the substrate particles. In that case, since the pigment particles adhering to the substrate are separated in a mixed solution of a solvent and a resin, the pigment particles may not be applied to a paint or the like.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the red color material composition of the present invention will be described in detail.
The red color material composition of the present invention contains a multilayer coated powder having not only the above-mentioned crystallized fine particle constituting film but also a film having another constitution capable of transmitting light on the surface of the base particle. It is.
As the low refractive index light-transmitting coating film, in the case where a metal hydroxide film or a metal oxide film is formed in a plurality of layers by a reaction of a metal salt or the like, the coating film (the base particle is coated) is used. A special function can be given by adjusting the thickness of each layer of the film layers involved in optical interference. For example, an alternating coating film having a different refractive index is formed on the surface of the base particle so that the refractive index n of the substance forming the coating is between 600 and 800 nm so as to satisfy the following formula (1). When a suitable thickness and number of alternating films having a thickness d corresponding to an integer m times one-fourth of the wavelength are provided, light having a wavelength λ between 600 and 800 nm (using Fresnel interference reflection) Is reflected or absorbed.
nd = mλ / 4 (1)
[0024]
Using this action, a film having a film thickness and a refractive index satisfying the formula (1) is formed on the surface of the base particle for a target wavelength of 600 to 800 nm, and further, The film having a reflection peak between 600 nm and 800 nm is formed by alternately coating the film having different refractive index once or more. At this time, the order of substances to be formed is determined as follows. First, when the refractive index of the substrate serving as the nucleus is high, the first layer is preferably a film having a low refractive index, and in the opposite case, the first layer is preferably a film having a high refractive index.
[0025]
The film thickness is measured and controlled as a reflected waveform using a spectrophotometer, etc., as the change in the optical film thickness, which is the product of the film refractive index and the film thickness. Design the thickness. For example, when the peak position of the reflection waveform of each unit film constituting the multilayer film is precisely matched to the range of 600 to 800 nm, a red-colored monochromatic colored powder can be obtained without using a dye or a pigment.
[0026]
However, in the case of an actual substrate, it is necessary to design in consideration of the particle size and shape of the substrate, the phase shift at the interface between the film material and the substrate particle material, and the peak shift due to the wavelength dependence of the refractive index. For example, when the shape of the base particle is a parallel plate, Fresnel interference due to the parallel film formed on the particle plane is designed under the condition that n in the above formula (1) is replaced with N in the following formula (2). To do. In particular, even when the substrate is in the shape of a parallel plate, when a metal film is included, the metal refractive index N in equation (2) includes an attenuation coefficient κ. In the case of a transparent oxide (dielectric), κ is very small and can be ignored.
N = n + iκ (i represents a complex number) (2)
When the attenuation coefficient κ is large, the phase shift at the interface between the film material and the substrate material becomes large, and all the layers of the multilayer film affect the optimum interference film thickness due to the phase shift.
[0027]
As a result, even if only the geometric film thickness is combined, the peak position is shifted, so that the color becomes light particularly when coloring in red. In order to prevent this, the influence of the phase shift on all the films is taken into consideration, and the combination of film thicknesses is designed in advance by computer simulation so as to be optimized.
Furthermore, there is a phase shift due to the oxide layer on the substrate surface and a peak shift due to the wavelength dependence of the refractive index. In order to correct these, it is necessary to find an optimum condition with a spectrophotometer or the like so that the reflection peak is in the range of 600 to 800 nm which is the target wavelength in terms of the final target film number.
[0028]
Interference of a film formed on a curved surface such as a spherical powder occurs in the same manner as a flat plate, and basically follows the Fresnel interference principle. Therefore, the coloring method can also be designed to be red. However, in the case of a curved surface, the light incident on and reflected by the powder causes complicated interference. These interference waveforms are almost the same as the flat plate when the number of films is small. However, as the total number increases, the interference inside the multilayer film becomes more complicated. In the case of a multilayer film, the reflection spectroscopic curve can be designed in advance by computer simulation so as to optimize the combination of film thicknesses based on Fresnel interference. In particular, in the case of forming a film on the surface of the substrate particles, the influence of the phase shift on the surface of the substrate particles and all the films is taken into account, and the design is made so as to optimize the combination of film thicknesses in advance by computer simulation. Furthermore, the peak shift for the oxide layer on the surface of the substrate particles and the peak shift due to the wavelength dependence of the refractive index are taken into account. In actual sample manufacturing, in order to correct these in the actual film with reference to the designed spectral curve, the film thickness is adjusted so that the reflection peak reaches the target wavelength in the range of 600 to 800 nm in terms of the final target film number with a spectrophotometer or the like. The optimal conditions must be found while changing
[0029]
Interference with the multilayer film also occurs when the powder of irregular shape is colored, and the basic film design is performed with reference to the condition of the interference multilayer film of spherical powder. The peak position of each unit film constituting the multilayer film can be adjusted by the film thickness of each layer, and the film thickness is the raw material in the coating forming conditions for forming a solid phase component such as a metal oxide on the surface of the base particle. By controlling the composition, the solid-phase deposition rate, the amount of the substrate, etc., the film thickness can be controlled with high accuracy, a film having a uniform thickness can be formed, and a desired red color can be colored.
As described above, by finding the optimum conditions while changing the film forming conditions such as the film forming solution so that the reflection peak and the absorption bottom are the target wavelengths in the range of 600 to 800 nm in the final target film number, You can get a body. Further, the color development due to multilayer film interference can be adjusted by controlling the combination of substances constituting the multilayer film and the thickness of each unit film. Thereby, the powder can be vividly colored in a desired red color without using a dye or a pigment.
[0030]
Below, the red color material composition of this invention and its manufacturing method are demonstrated in detail.
In the red color material composition of the present invention and the method for producing the same, the base particles serving as a reference for forming the metal oxide film or the like are not particularly limited, and may be an inorganic substance or an organic substance containing a metal, a magnetic substance, a dielectric substance, Conductors and insulators may be used.
When the substrate is a metal, any metal such as iron, nickel, chromium, titanium, and aluminum may be used. However, in the case of utilizing the magnetism, a material having magnetism such as iron is preferable. These metals may be alloys, and when they have the above magnetism, it is preferable to use a ferromagnetic alloy.
In addition, when the powder substrate is a metal compound, typical examples thereof include the above-mentioned metal oxides, such as iron, nickel, chromium, titanium, aluminum, silicon, etc., calcium Further, oxides such as magnesium and barium, or composite oxides thereof may be used. Furthermore, examples of metal compounds other than metal oxides include metal nitrides, metal carbides, metal sulfides, metal fluorides, metal carbonates, and metal phosphates.
[0031]
Further, as the base particles, other than metals, they are semi-metallic and non-metallic compounds, particularly oxides, carbides and nitrides, and silica, glass beads and the like can be used. Other inorganic substances include inorganic hollow particles such as shirasu balloon (hollow silicic acid particles), fine carbon hollow spheres (clecas spheres), fused alumina bubbles, aerosil, white carbon, silica fine hollow spheres, calcium carbonate fine hollow spheres, Mica such as calcium carbonate, pearlite, talc, bentonite, synthetic mica and muscovite, kaolin and the like can be used.
[0032]
As the organic substance, resin particles are preferable. Specific examples of the resin particles include cellulose powder, cellulose acetate powder, polyamide, epoxy resin, polyester, melamine resin, polyurethane, vinyl acetate resin, silicon resin, acrylic ester, methacrylic ester, styrene, ethylene, propylene, and these. And spherical or crushed particles obtained by polymerization or copolymerization. Particularly preferred resin particles are spherical acrylic resin particles obtained by polymerization of acrylic acid or methacrylic acid ester.
However, when the resin particles are used as a substrate, the heating temperature in drying must be equal to or lower than the melting point of the resin.
[0033]
As the shape of the substrate, isotropic bodies such as spheres, subspheres, regular polyhedrons, rectangular parallelepipeds, spheroids, rhombohedrons, plate-like bodies, needle-like bodies (columns, prisms), and pulverized materials A completely amorphous powder can also be used.
These substrates are not particularly limited in terms of particle size, but those in the range of 0.01 μm to several mm are preferable.
In addition, the specific gravity of the base particles is in the range of 0.1 to 10.5. When the obtained powder is used by dispersing it in a liquid or the like, the surface of fluidity and floatability is used. To 0.1 to 5.5, more preferably 0.1 to 2.8, and still more preferably 0.5 to 1.8. When the obtained powder is used dispersed in a liquid or the like, if the specific gravity of the substrate is less than 0.1, the buoyancy in the liquid is too large, and the film needs to be multilayered or very thick, which is uneconomical. On the other hand, if it exceeds 10.5, the film for floating becomes thick, which is similarly uneconomical.
[0034]
In the present invention, as described above, the powder base particles are covered with a plurality of coating layers having different refractive indexes, and the interference color is selected by appropriately selecting the refractive index and the layer thickness of each coating layer. By this, it is possible to obtain a powder that is colored red and expresses a specific interference reflection peak other than the visible light region.
As described above, a metal hydroxide film or a metal oxide film is deposited on the surface of the base particle by the reaction of a metal salt, but a buffer solution is used as a solvent for the solid phase deposition reaction, and at a certain pH. Precipitate at an appropriate rate.
[0035]
In the present invention, the metal used as the metal salt is iron, nickel, chromium, titanium, zinc, aluminum, cadmium, zirconium, silicon, tin, lead, lithium, indium, neodymium, bismuth, cerium, antimony, etc. Calcium, magnesium, barium etc. are mentioned. Examples of these metal salts include sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, carbonic acid and carboxylic acid salts. Furthermore, chelate complexes of the above metals are also included. The type of metal salt used in the present invention is selected according to the properties to be imparted to the surface of the substrate and the means applied during production.
Since the powder of the present invention basically forms a colorless and transparent film and is colored by laminating films having different refractive indexes, the above-mentioned metals and salts thereof are mentioned. If the reflection and absorption spectrum waveforms are not the desired color, the following metals cobalt, yttrium, sulfur, europium, dysprosium, antimony, samarium, copper, silver, gold, platinum, rhodium, iridium, tungsten, Examples include salts of sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, carbonic acid, and carboxylic acid of metals such as iron and manganese. Furthermore, the chelate complex of the said metal is also contained. The content of these metals in the film is 10 ppm to 15%, preferably 10 ppm to 15%, and more desirably 50 ppm to 5%.
When the content of these metals is small, the coloring becomes insufficient, and when it is too much, the coloring becomes too strong and the color becomes dark, resulting in inconvenience that the light-colored powder that is the target of the present invention cannot be obtained.
[0036]
A plurality of layers of these metal salt films such as metal oxides may be formed. If necessary, a metal oxide obtained by hydrolysis of a metal alkoxide or the like may be formed on the metal oxide film. A film formed by a film forming method can also be formed.
In this way, a multilayer film can be formed on the substrate particles, and at that time, by setting the formation conditions so that the thickness of each layer has a predetermined thickness, the desired characteristics can be obtained. In addition, it is possible to form a multi-layered film of a metal oxide or the like using a metal salt which is a simple material and is an inexpensive raw material. In particular, it is an important advantage that a multilayer film-coated powder can be obtained without using an expensive metal alkoxide as a raw material.
[0037]
In the method for producing the red color material composition containing the red powder of the present invention, the multilayer coating film may be produced as a continuous process, or each coating film is produced one by one, or a single layer. It can be produced by various methods such as combining production and multi-layer continuous production.
The particle size of the red color material composition according to the present invention is not particularly limited and can be appropriately adjusted according to the purpose, but is usually in the range of 0.1 μm to several mm, preferably 0.1 μm to 200 μm. is there.
[0038]
In the present invention, the thickness of the metal oxide film formed at one time can be in the range of 5 nm to 10 μm, and can be made thicker than the conventional forming method.
As the total thickness of the metal oxide film formed in a plurality of times, in the case of the above-described color magnetic powder, in order to form a metal oxide film having a good reflectivity due to the interference, it is 10 nm to 20 μm. The range is preferable, and more preferably 20 nm to 5 μm. In order to interference-reflect visible light with a particularly thin film thickness such as a limited particle size, it is preferably in the range of 0.02 to 2.0 μm.
[0039]
As described above, the red color material composition of the present invention uses an aqueous solvent having a constant pH as the film-forming reaction solvent, particularly when the film-forming reaction is performed in an aqueous solvent during the film-forming reaction in the production method. At the same time, a film coating reaction is formed by a film forming reaction on the surface of the substrate under ultrasonic dispersion conditions.
In the present invention, in order to make the film forming reaction constant, a buffering agent is added to an aqueous solvent to form a buffer solution, or a buffer solution prepared in advance is used. In the film forming reaction, film materials other than the buffer solution are added to form a film. When film formation is performed by adding a film forming raw material, if the pH fluctuates greatly, it is desirable to add a buffer solution to prevent this.
In the present invention, the constant pH means that the pH is within ± 2 of the predetermined pH, preferably within ± 1, and more preferably within ± 0.5.
[0040]
Various buffering solutions are used and are not particularly limited. First, it is important that the base particles are sufficiently dispersible. At the same time, metal hydroxide or metal oxide film-coated powder deposited on the surface of the base is also used. It is necessary to select so as to satisfy the conditions that can be dispersed by the action of the electric double layer and that a dense film can be formed by the slow dropping reaction.
Therefore, the production method of the film-coated powder of the present invention is different from the conventional method of neutralization by reaction of metal salt solution, precipitation by isoelectric point, or decomposition and precipitation by heating.
[0041]
Next, as an ultrasonic dispersion condition, various ultrasonic oscillators can be used. For example, a water tank of an ultrasonic cleaning machine can be used, and is not particularly limited. However, the ultrasonic dispersion conditions of the present invention vary depending on the size of the oscillation device, the shape and size of the reaction vessel, the amount of reaction solution, the volume, the amount of substrate particles, etc. Appropriate conditions may be selected.
The buffer solution used in the present invention depends on the solid phase component to be precipitated, and is not particularly limited. However, Tris, boric acid, glycine, succinic acid, lactic acid, acetic acid, tartaric acid, hydrochloric acid And the like.
[0042]
Next, as an example, a method of forming an alternating multilayer film of a metal oxide having a high refractive index and a metal oxide having a low refractive index will be specifically described, particularly when a film forming reaction is performed in an aqueous solvent. First, when forming a film such as titanium oxide or zirconium oxide, the base particles are immersed in a buffer solution such as acetic acid / sodium acetate and dispersed by ultrasonic oscillation, and titanium sulfate which is a metal salt such as titanium or zirconium. Alternatively, zirconium sulfate or the like can be used as a raw material, and an aqueous solution of these metal salts can be slowly dropped into the reaction system, and the resulting metal hydroxide or metal oxide can be precipitated around the base particles. During this dropping reaction, the pH is maintained at the pH of the buffer solution (5.4).
After completion of the reaction, this powder is separated into solid and liquid, washed and dried, and then subjected to heat treatment. The drying means may be either vacuum drying or natural drying. It is also possible to use a device such as a spray dryer in an inert atmosphere.
When the film to be coated is titanium oxide, the formation of titanium oxide is represented by the following reaction formula.
Ti (SO_Four)₂+ 2H₂O → TiO₂+ 4H₂(SO_Four)₂
Titanyl sulfate TiO₂The content is preferably 5 g / liter to 180 g / liter, more preferably 10 g / liter to 160 g / liter. If it is less than 5 g / liter, it takes too much time to form a film, and the amount of powder processing is reduced, which is uneconomical. If it exceeds 180 g / liter, the diluted solution undergoes hydrolysis during the addition and does not become a film-forming component. Both are unsuitable.
[0043]
Subsequently, when a film such as silicon dioxide or aluminum oxide is formed, KCl / H_ThreeBO_ThreeThe above titania-coated particles are immersed and dispersed in a buffer solution in which NaOH is added to the system, etc., and a metal salt such as silicon or aluminum such as sodium silicate or aluminum chloride is used as a raw material, and an aqueous solution of these metal salts is reacted. It can be carried out by dripping gently into the system and precipitating the produced metal hydroxide or metal oxide around the base particles. During this dropping reaction, the pH is maintained at the pH of the buffer solution (9.0).
After completion of the reaction, this powder is separated into solid and liquid, washed and dried, and then subjected to heat treatment. By this operation, by repeating the operation of forming two layers of metal oxide films having different refractive indexes on the surface of the base particles, a powder having a multilayer metal oxide film on the surface can be obtained.
When the film to be coated is silicon dioxide, the formation of silicon dioxide is represented by the following reaction formula.
Na₂Si_XO_{2X + 1}+ H₂O → XSiO₂+ 2Na⁺+ 2OH^-
[0044]
Next, the crystallized fine particle constituting film included in the red powder contained in the red color material composition of the present invention is composed of any substance as long as it can scatter and reflect light and increase the brightness. However, it is preferable to use a material having a high refractive index.
The substance having a high refractive index is not particularly limited, but oxides such as titanium oxide (titania), zirconium oxide, bismuth oxide, cerium oxide, antimony oxide, and indium oxide can be used. Most preferred is titanium oxide (titania).
[0045]
As a method for forming the crystallized fine particle constituting film as described above, a method by solid phase precipitation in a film forming reaction liquid phase or the like is used.
Specifically, the metal alkoxide in an organic solvent described in JP-A-6-228604, JP-A-7-90310 and International Publication WO96 / 28269 previously proposed by the present inventors. Examples include a solid-phase precipitation method by hydrolysis (metal alkoxide method) and a solid-phase precipitation method (aqueous method) by reaction from a metal salt in an aqueous solution described in the specification attached to Japanese Patent Application No. 9-298717. It is done.
In this case, in the film-forming reaction solution, the reaction solution is set so that the solid-phase fine particles precipitate in the reaction solution at a higher rate than the rate at which the precipitate film grows on the surface of the substrate particles (line growth rate). The concentration, the added catalyst amount, and the base particle dispersion amount are adjusted.
As described above, the solid phase fine particles precipitated in the film-forming reaction solution are attached to the surface of the substrate particles, thereby forming a coating film composed of the solid phase fine particles.
[0046]
At this point, the solid phase fine particles incorporated into the film are amorphous, the voids between the solid phase fine particles are not formed, light scattering and reflection do not occur, and the mechanical strength of the film is very high. It is low. Therefore, the coating film composed of the solid phase fine particles is fired. By this firing, the amorphous solid phase fine particles are crystallized, and voids are also formed between the crystallized fine particles, so that the above-mentioned crystallized fine particle constituting film that scatters and reflects light is obtained.
[0047]
In order to form the crystallized fine particle constituting film, the aqueous method is preferable to the above-described metal alkoxide method because it is simpler to make the relationship between the line growth rate and the solid phase precipitation rate more suitable.
Further, the metal alkoxide method requires expensive metal alkoxide as a raw material and a relatively expensive and dangerous organic solvent as a reaction solvent. For this reason, the manufacturing apparatus or equipment must also be explosion-proof, and the cost performance is worsened. From this point, the aqueous method is preferable to the metal alkoxide method.
In addition, when the core particle is a substance that is unstable with respect to water even if it is a metal or an oxide, the first layer is formed and stabilized by the metal alkoxide method, so that the second and subsequent layers are treated by an aqueous method. The combined method of coating with is preferred.
[0048]
The firing may be performed after the coating film composed of the solid phase fine particles is formed. However, when the coating film becomes a crystallized fine particle constituting film on the coating film, the firing may be performed. It is desirable from the viewpoint of the film strength of the resulting red powder to be performed after coating with ultrafine particles capable of forming a dense film for closing the voids on the surface.
Firing is preferably performed at 300 to 1200 ° C.
[0049]
In the red color material composition of the present invention, the crystallized fine particle constituting film of the red powder contained may be two or more layers. In that case, a light-transmitting coating film having a low refractive index is preferably present between the two crystallized fine particle constituting films. The low refractive index light-transmitting coating film is not particularly limited, and examples thereof include those made of a metal compound, an organic substance, and the like.
[0050]
Examples of the metal compound include metal oxides, metal sulfides, metal selenides, metal tellurides, and metal fluorides. More specifically, zinc oxide, aluminum oxide, cadmium oxide, titanium oxide, zirconium oxide, tantalum oxide, silicon oxide, antimony oxide, neodymium oxide, lanthanum oxide, bismuth oxide, cerium oxide, tin oxide, magnesium oxide, lithium oxide Lead oxide, cadmium sulfide, zinc sulfide, antimony sulfide, cadmium selenide, cadmium telluride, calcium fluoride, sodium fluoride, trisodium aluminum fluoride, lithium fluoride, magnesium fluoride, and the like can be suitably used.
[0051]
A method for forming the metal compound film will be described below.
As a film forming method, a method of directly depositing on the surface of the base particles by a vapor deposition method such as a PVD method, a CVD method or a spray drying method is possible.
However, the metal alkoxide method described in the above-mentioned JP-A-6-228604, JP-A-7-90310 or International Publication WO96 / 28269 proposed by the present inventors, or Japanese Patent Application No. 9- The aqueous method described in the specification of 298717 is preferable.
In this case, unlike the above-mentioned film formation of the crystallized fine particle constituent film, the linear growth rate is made higher than the solid phase deposition rate, and the reaction conditions are adjusted so that an amorphous uniform film is formed.
[0052]
Although it does not specifically limit as said organic substance, Preferably it is resin. Specific examples of the resin include cellulose, cellulose acetate, polyamide, epoxy resin, polyester, melamine resin, polyurethane, vinyl acetate resin, silicon resin, acrylic ester, methacrylic ester, styrene, ethylene, propylene, and derivatives thereof. Examples thereof include a polymer or a copolymer.
(1) When forming an organic film (resin film),
a. A method of dispersing a base particle in a liquid phase and emulsion polymerization to form a resin film on the particle (polymerization method in a liquid phase); b. A film forming method (CVD) (PVD) in the gas phase is employed.
[0053]
An example of producing a powder having a multilayer film on a base particle as the red powder contained in the red color material composition of the present invention is shown below.
For example, if the base particles are made of a material having a high refractive index, a light-transmitting film having a low refractive index is provided thereon, and further a particle constituting film having a high refractive index is provided thereon. Are alternately provided with a light-transmitting film having a low refractive index. Further, if the substrate particles have a low refractive index, a high refractive index particle constituting film thereon, a low refractive index light-transmitting film thereon, and a high refractive index particle constituting film thereon And provide sequentially.
[0054]
Next, specific raw materials used for film formation in the present invention, particularly metal salts will be described.
The raw materials used to form a film having a high refractive index include titanium halides and sulfates for titanium oxide films, and zirconium halides, sulfates and carboxylic acids for zirconium oxide films. Salts, oxalates, chelate complexes, etc., for cerium oxide films, cerium halides, sulfates, carboxylates, oxalates, etc., for bismuth oxide films, bismuth halides, nitrates, carboxylic acids For indium oxide films such as salts, indium halides, sulfates and the like are preferable.
In addition, as a raw material used to form a film having a low refractive index, for silicon oxide films, organic silicon compounds such as sodium silicate, water glass, silicon halide, alkyl silicate, and polymers thereof are used. For aluminum oxide films, aluminum halides, sulfates, chelate complexes, etc. are preferred, and for magnesium oxide films, magnesium sulfates, halides, etc. are preferred.
Further, for example, in the case of a titanium oxide film, mixing titanium sulfate with titanium chloride has an effect of becoming a rutile type titanium oxide film having a higher refractive index at a lower temperature.
[0055]
Further, a more complete oxide film can be produced by controlling the reaction temperature at the time of coating to a temperature suitable for the type of each metal salt.
When the film formation reaction (solid phase deposition reaction) on the surface of the substrate in the aqueous solvent is too slow, the solid phase deposition reaction can be promoted by heating the reaction system. However, if the heat treatment for heating is excessive, the reaction rate is too high, and the supersaturated solid phase does not become a film, but precipitates in an aqueous solution, forms gels or fine particles, and the film thickness control becomes difficult.
[0056]
After the production of the coating film, repeated washing with tilted water while adding distilled water to remove the electrolyte, followed by heat treatment such as drying and baking, removing the water contained in the solid phase to completely remove the oxide. A film is preferred. Further, by heat-treating the powder after film formation in a rotary tube furnace or the like, sticking can be prevented and dispersed particles can be obtained.
In order to form a hydroxide film or an oxide film and heat-treat it, it may be heat-treated every time each layer is coated, or may be finally heat-treated after the target multilayer film is completed.
The heat treatment conditions vary depending on the reaction system, but the heat treatment temperature is 200 to 1300 ° C, preferably 400 to 1100 ° C. Below 200 ° C., salts and moisture may remain. When the temperature exceeds 1300 ° C., the film and the substrate may react with each other to form different substances, both of which are unsuitable. The heat treatment time is 0.1 to 100 hours, preferably 0.5 to 50 hours.
[0057]
Next, in the case of preparing the red color material composition according to the present invention, (1) red ink or paint-like composition (fluid) and (2) red toner and red dry ink-like composition (powder) will be described. To do.
(1) In the present invention, a conventionally known varnish used for color printing, color magnetic printing, and color magnetic coating can be used as the medium (vehicle) of the red ink or paint-like composition (fluid). For example, a liquid polymer, a polymer or a monomer dissolved in an organic solvent can be appropriately selected and used according to the kind of powder, the ink application method, and the use.
[0058]
Examples of the liquid polymer include dienes such as polypentadiene and polybutadiene, polyethylene glycols, polyamides, polypropylenes, waxes, and copolymer knitted bodies thereof.
Polymers that are soluble in organic solvents include olefin polymers, acrylic resins such as oligoester acrylates, polyesters, polyamides, polyisocyanates, amino resins, xylene resins, ketone resins, and diene resins. Rosin-modified phenolic resins, diene rubbers, chloroprene resins, waxes, modified products and copolymers thereof, and the like.
Examples of the monomer that can be dissolved in the organic solvent include styrene, ethylene, butadiene, and propylene.
Examples of organic solvents include alcohols such as ethanol, isopropanol, and normal propanol, ketones such as acetone, benzene, toluene, xylene, kerosene, benzine hydrocarbons, esters, ethers, and modified products and copolymers thereof. Can be mentioned.
[0059]
(2) Red toner, red dry ink, red dry paint-like composition (powder) is a screw-type extruder comprising the above-mentioned red color material multilayer film coated powder, a resin and, if necessary, a toning material. , Knead directly with a roll mill, kneader, etc., coarsely pulverize with a hammer mill, cutter mill, etc., then finely pulverize with a jet mill, etc. be able to. The red color material multilayer film-coated powder can also be made into a powdery red color material composition by using a polymerization method such as an emulsion polymerization method or a suspension polymerization method.
Further, the red multilayer coating powder, resin, additives such as toning agents, and solvents can be liquefied with a colloid mill or three rolls to form a liquid red color material composition such as ink paint.
As the toning material for increasing the brightness, it is a red pigment (color developing material), for example, titanium oxide, zinc oxide, tin oxide, silicon oxide, antimony oxide, lead oxide or the like, or complex oxides thereof, Carbonates such as calcium carbonate, magnesium carbonate, barium carbonate, sulfates such as barium sulfate and calcium sulfate, sulfides such as zinc sulfate, or composite oxides obtained by sintering the oxides, carbonates and sulfates, A composite hydrous oxide is mentioned.
In order to adjust saturation and hue, especially to improve color reproducibility with full color mixing, as a toning agent, red inorganic pigments such as sulfide pigments such as cadmium red and mercury red,
Permanent red, para red and other azo series, brilliant fast red, fast scarred and other fast pigments such as oil red, oil pink and other oil dyes, methanol red, methanol pink and other alcohol dyes, eosin lake, rhodamine lake, etc. Red organic dyes or red organic pigments such as lake dyes, quinacridone dyes and pigments such as Cinquasis Red, and the like. However, the toning agent of the present invention is not limited to these.
Furthermore, when it is necessary to perform color adjustment using pigments or dyes such as blue, yellow, and reddish purple in delicate color tone control, it is preferable to add these pigments to obtain an optimal red color.
In the case of this powdery red color material composition, (a) the resin for production by the above pulverization method is not particularly limited, but polyamide, epoxy resin, polyester, melamine resin, polyurethane, vinyl acetate Examples thereof include resins, silicon resins, acrylic esters, methacrylic esters, styrene, ethylene, butadiene, propylene, and polymers or copolymers of these derivatives.
(B) In the case of a polymerization method, polymerization is started from one or a mixture of esters, urethane, vinyl acetate, organic silicon, acrylic acid, methacrylic acid, styrene, ethylene, butadiene, propylene, etc. These copolymers are formed.
[0060]
As described above, the red color material composition of the present invention takes the form of (1) red ink or paint-like composition (fluid) and (2) red toner, red dry ink-like composition (powder).
In the case of fluid, it is red ink, paint, etc., the toning material, a slow-drying resin, a solidification accelerator, a thickener to increase the viscosity, a fluidizing agent to decrease the viscosity, Components such as a dispersing agent can be included for dispersing the particles.
On the other hand, in the case of powder, (a) when powder is produced by a pulverization method, the toning material, a slow-drying resin, a solidification accelerator, and a fluid to reduce the viscosity during kneading. In order to disperse the agent and the particles, a component such as a dispersant, a charge adjusting agent for fixing on paper or the like, and a wax can be included.
(B) When a polymerization method is used, the toning material, the polymerization initiator, the polymerization accelerator, a thickener for increasing the viscosity, and a dispersing agent for fixing particles, fixing to paper, etc. Ingredients such as a charge control agent and wax may be included.
The multilayer coating powder in the red color material composition of the present invention can be applied to wet and dry color printing and wet and dry color magnetic printing by combining a single powder or a plurality of powders having different spectral characteristics. In addition, using three primary color powders, it has a discrimination function of 6 combinations of visible light, invisible light (ultraviolet and infrared), fluorescent color and magnetism, and electricity (electric field change). It can be applied to other uses that require a security function such as color magnetic ink for preventing counterfeiting.
[0061]
When the red color material composition of the present invention is applied as a red ink, a paint-like composition or a red toner, a red dry ink-like composition, or a red dry paint composition, printed on a substrate, melt-transferred or applied to a substrate The relationship between the content of the red color material multilayer coating powder and the resin in the red color material composition is 1: 0.5 to 1:15 in volume ratio. When the content of the medium is too small, the applied film does not adhere to the object to be coated. On the other hand, if the amount is too large, the color of the pigment becomes too thin to be a good ink or paint. Further, the relationship between the amount of the red ink or the resin combined with the red color material and the resin in the coating composition and the amount of the solvent is 1: 0.5 to 1:10 in volume ratio, and the amount of the solvent is too small. The viscosity of the paint is high and it cannot be applied uniformly. Moreover, when there is too much quantity of a solvent, time will be required for drying of a coating film, and the efficiency of an application | coating operation will fall extremely.
[0062]
In addition, the color density of the coating film when printing, melt transfer, or coating on the substrate is determined by the amount of pigment placed per unit area of the substrate. The amount of the red color material multilayer coating powder of the present invention on the object to be coated after the paint is dried is 0.1 to 300 g per square meter in area density when uniformly coated, and preferably is 0.00. If it is 1-100g, a favorable coating color will be obtained. If the area density is smaller than the above value, the ground color of the object to be coated appears, and if it is larger than the above value, the color density of the painted color does not change, which is uneconomical. That is, even if the pigment is placed on the object to be coated more than a certain thickness, the light does not reach the pigment below the coating film. Making the coating film thicker than this thickness is uneconomical because it has a coating thickness that is beyond the hiding power of the coating material, and has no coating effect. However, in consideration of wear of the coating film, the thickness of the coating film is worn down.
[0063]
【Example】
The present invention will be described more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples.
[Example 1] (Red color material composition 1 using magnetic material, aqueous two-layer coating)
(Formation of first layer silica film)
(1) Adjustment of buffer solution
A buffer solution 1 was prepared by dissolving 0.4 M potassium chloride reagent and 0.4 M boric acid in 1 liter of water.
0.4 M sodium hydroxide was dissolved in 1 liter of water to obtain a buffer solution 2.
250 ml of the buffer solution 1 and 115 ml of the buffer solution 2 were mixed and homogenized to obtain a buffer solution 3.
(2) Sodium silicate aqueous solution (water glass solution)
Dilute sodium silicate reagent with pure water,₂The concentration was adjusted so that the content was 10 wt%.
[0064]
(3) Silica film
As a base particle, 15 g of magnetite powder (average particle size 2.3 μm) was added to a previously prepared mixture of 177 ml of buffer solution 3 (pH: about 9.0) and 124 ml of pure water to prepare a dispersion. . The container containing this dispersion was placed in a water tank of an ultrasonic cleaning machine (US-6 type, manufactured by Iuchi Seieido Co., Ltd.) filled with water, and 28 kH._ZWhile applying ultrasonic waves in a 200 W ultrasonic bath, the magnetite powder was further dispersed in the buffer solution 3 with stirring. To this, 99 ml of an aqueous sodium silicate solution prepared in advance was added at a rate of 40 ml / min, and the mixture was gradually reacted and decomposed to deposit a silica film on the surface.
After the addition of the aqueous sodium silicate solution, the reaction was further continued for 2 hours to react all unreacted raw materials. After completion of the film forming reaction, the slurry containing the silica film powder was repeatedly decanted with sufficient water and washed.
After washing, the silica film powder is put in a vat, separated and separated, the upper liquid is discarded, and then dried in air at 150 ° C. for 8 hours in a drier to obtain silica-coated magnetite powder A₁Got.
[0065]
(Formation of second-layer titania film)
(1) Adjustment of buffer solution
0.3 M acetic acid and 0.9 M sodium acetate were dissolved in 1 liter of deionized water to obtain a buffer solution 4.
(2) Titanium sulfate aqueous solution
Concentration is TiO₂Was added to water to adjust the dilution to 100 g / liter, and the dilution was adjusted to obtain an aqueous titanium sulfate solution.
[0066]
(3) Titania film formation
4 g of the above powder A₁On the other hand, 484 ml of buffer solution 4 (pH: about 8.4) was prepared, and powder A was put in buffer solution 4.₁Was sufficiently dispersed in an ultrasonic bath while being ultrasonically dispersed in the same manner as in the silica film formation. Thereafter, 57 ml of a previously prepared titanium sulfate aqueous solution was dropped at 1.9 ml / min while maintaining the temperature of the liquid at 50 to 55 ° C., and solid phase fine particles were precipitated in the liquid to make the liquid thin and cloudy. Then powder A₁In order to fix the solid phase fine particles on the surface, the dropping rate was lowered to 1.5 ml / min, and the unreacted component was gradually deposited. Then, the solid phase fine particles precipitated in the liquid were fixed to the surface of the base particle, and the surface was covered with ultrafine particles having a particle diameter smaller than that of the solid phase fine particle fixed to the surface of the base particle.
[0067]
(4) Washing and drying
After completion of the film-forming reaction, decantation was repeated with pure water to remove unreacted components, persulfuric acid and sulfuric acid formed by the reaction, followed by solid-liquid separation, and drying with a vacuum dryer to obtain a dry powder.
The obtained dry powder is heat-treated (fired) at 650 ° C. for 30 minutes in a rotary tube furnace, and the silica / titania-coated magnetite powder A having a smooth surface is obtained.₂Got.
This two-layer film-coated powder A₂Was yellowish red, and its magnetization at 1 kOe was 31.4 emu / g. This two-layer film-coated powder A₂The maximum reflection peak of was 728 nm and became bright red.
[0068]
The peak wavelength of the spectral reflection curve of the coating powder of the coating film, the reflectance at the peak wavelength, the refractive index and the film thickness of the coating film were measured by the following methods.
1) The spectral reflection curve was measured by measuring the reflected light of a powder sample packed in a glass holder using a spectrophotometer with an integrating sphere manufactured by JASCO. The measuring method was measured according to JISZ8723 (1988).
2) The refractive index and the film thickness were evaluated by obtaining the spectral reflection curve measurement results of the film thickness samples prepared under different conditions by fitting with the instrument calculation curve based on the interference equation.
[0069]
(5) Surface hydrophobization treatment of multilayer coating powder
Obtained silica / titania coated powder A₂10 g was dispersed in 200 ml of an ethanol solution in which 0.2 g of silicon ethoxide was dissolved, and the container was heated in an oil bath to keep the temperature of the liquid at 55 ° C. 3 g of ammonia water (29% concentration) was added thereto, stirred for 3 hours, filtered, dried in a vacuum dryer at 100 ° C. for 2 hours, and hydrophobized red multilayer coating powder A_ThreeGot.
[0070]
(6) Adhesive resin layer
(Polystyrene composite powder, toner)
Red-colored multilayer coating powder A, which has been made oleophilic to 100 g of styrene monomer in advance by the aforementioned surface treatment method_ThreeThe mixture was stirred and homogenized with a high-speed stirrer until 100 g was dispersed.
A solution of this styrene monomer and particles dissolved in 500 g of distilled water of sodium n-dodecyl sulfate was added at 70 ° C. while stirring at high speed, and stirred until the emulsified particles were sufficiently finely divided.
10 g of 10% ammonium persulfate aqueous solution was added thereto, and the mixture was reacted for 4 hours with stirring.
After completion of the reaction, dilute with 2 liters of distilled water, discard the top solution by decantation and collect the precipitate. The precipitate was dried on a filter paper to obtain red polystyrene-coated powder A. The obtained red powder A was spherical, and the magnetization at a magnetic field of 1 kOe was 15.0 emu / g.
Table 1 shows the refractive index and film thickness of the first and second layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0071]
[Table 1]

[0072]
[Example 2] (Red color material composition 2 using magnetic material, aqueous three-layer coating)
(Formation of first layer silica film)
(1) Silica film
As base particles, 15 g of spherical magnetite powder (average particle size 2.3 μm) was placed in 261 ml of the buffer solution 3 (pH: about 9.0) prepared in advance to prepare a dispersion. The container containing this dispersion was placed in a water tank of a water-filled ultrasonic cleaning machine (US-6 type, manufactured by Iuchi Seieido Co., Ltd.), and 26 kH_ZFurther, while applying ultrasonic waves in a 600 W ultrasonic bath, the mixture was further dispersed with stirring in the buffer solution 3 containing magnetite powder. To this, 139 ml of an aqueous sodium silicate solution prepared in advance was added at a rate of 40 ml / min, and the mixture was gradually reacted and decomposed to deposit a silica film on the surface.
[0073]
After the addition of the aqueous sodium silicate solution, the reaction was further continued for 2 hours to react all unreacted raw materials. After completion of the film forming reaction, the slurry containing the silica film powder was repeatedly decanted with sufficient water and washed. After washing, the silica film powder is placed in a vat, separated and separated, and the upper solution is discarded. After drying in a dryer at 150 ° C. for 8 hours in air, heat treatment (firing is performed at 500 ° C. for 30 minutes in a nitrogen atmosphere. And silica-coated magnetite powder B₁Got.
[0074]
(Formation of second-layer titania film)
In the same manner as in Example 1, a buffer solution 4 and an aqueous titanium sulfate solution were prepared and prepared.
5.5 g of powder B₁In contrast, 1313 ml of the buffer solution 4 (pH: about 8.4) was prepared, and the powder B was put in the buffer solution 4.₁Was sufficiently dispersed in an ultrasonic bath while ultrasonically dispersing in the same manner as in the silica film formation. Thereafter, a previously prepared titanium sulfate aqueous solution was gradually added dropwise at a constant rate of 1.8 ml / min while maintaining the temperature of the solution at 50 to 55 ° C.
At the beginning of the dropping, solid phase fine particles were precipitated in the liquid, but were fixed on the surface of the base particle, and the surface was covered with ultrafine particles having a particle diameter smaller than that of the solid phase fine particle fixed on the surface of the base particle. , Silica / titania coated magnetite powder B₂Got. This two-layer film-coated powder B₂Is light red, the maximum reflection peak is 722 nm, and the powder A obtained in Example 1₁It was the same.
This powder B₂The surface of the film was slightly uneven, and the protrusions of titania particles were partially observed.
[0075]
(Third layer silica film formation, when the titania film surface is confined by a silica thin film)
In the same manner as in Example 1, buffer solutions 1 and 2 and an aqueous sodium silicate solution (water glass solution) were prepared.
Powder silica / titania-coated magnetite powder B₂A silica film was formed on 15 g. The amount of the buffer solution was the same as that of the first layer coating, but the dropping rate of the sodium silicate aqueous solution was the same, and the dropping amount was set to 261 ml, and the film was reacted for 2 hours until there was no unreacted substance. After washing, heat treatment (baking) is performed at 500 ° C. for 30 minutes in a nitrogen atmosphere in a rotary tube furnace, and silica / titania-coated magnetite powder B_ThreeGot.
[0076]
Obtained powder B_ThreeBecame a light red powder with large light scattering, with titania fine particles crystallizing between two layers of silica film having a smooth surface. B_ThreeThe surface of the film was free of irregularities, was almost smooth, and had no holes, cracks, or dents.
In observation with a transmission electron microscope, crystallization of titania fine particles was observed between the two silica layers, and voids were present between the particles. It is done.
This three-layer film-coated powder B_ThreeThe maximum reflection peak of was 723 nm.
[0077]
(Adhesive resin layer, polystyrene composite powder)
Red color material multi-layer coating powder B, which has been made oleophilic to 100 g of styrene monomer in advance by the aforementioned surface treatment method₃As with 100 g, 10 g of oleophilic titanium oxide was stirred with a high-speed stirrer until it was dispersed and homogenized.
A solution of this styrene monomer and particles dissolved in 500 g of distilled water of sodium n-dodecyl sulfate was added at 70 ° C. while stirring at high speed, and stirred until the emulsified particles were sufficiently finely divided.
10 g of 10% ammonium persulfate aqueous solution was added thereto, and the mixture was reacted for 4 hours with stirring.
After completion of the reaction, dilute with 2 liters of distilled water, discard the top solution by decantation and collect the precipitate. The precipitate was dried on filter paper to obtain red polystyrene-coated powder B.
The obtained powder of red color material composition B was spherical and had a magnetization of 15 emu / g at a magnetic field of 1 kOe.
Table 2 shows the refractive indexes and film thicknesses of the first to third layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0078]
[Table 2]

[0079]
[Example 3] (Red color material composition 3 using a magnetic material, in the case where scattering particles are attached to the surface, an aqueous four-layer coating)
(Formation of first layer silica film)
As base particles, 40 g of magnetite powder (average particle size 0.7 μm) was prepared in the same manner as in Example 1 with 3126 g of the buffer solution 3 (pH: about 9.0) prepared in advance and 260 ml of pure water. 28kH in a mixed solution to make a dispersion_ZFurther, while applying ultrasonic waves in a 600 W ultrasonic bath, the mixture was further dispersed with stirring in the buffer solution 3 containing magnetite powder. To this, 1302 ml of an aqueous sodium silicate solution prepared in advance was gradually added at 2.67 ml / min to deposit a silica film on the surface.
After the addition of the aqueous sodium silicate solution, the reaction was further continued for 2 hours to react all unreacted raw materials.
After completion of the film forming reaction, the slurry containing the silica film powder was repeatedly decanted with sufficient water and washed.
After washing, the silica membrane powder is put into a vat, separated and separated, and the upper liquid is discarded.₁Got.
[0080]
(Formation of second-layer titania film)
40 g of the above powder C₁In contrast, 5210 g of the buffer solution 4 and 5210 ml of pure water were prepared, and C₁Was sufficiently dispersed in an ultrasonic bath while being ultrasonically dispersed in the same manner as in the silica film formation. Thereafter, while maintaining the temperature of the liquid at 50 to 55 ° C., 2110 ml of a titanyl sulfate aqueous solution (TiO 2) prepared in advance.₂15 w%) was gradually added dropwise at a constant rate of 1.25 ml / min, and the addition was terminated while the solution was slightly clouded.
After completion of the dropwise addition, the reaction was further continued for 3 hours, the unreacted portion was gradually precipitated, and the particles were taken into the film.
After completion of the film-forming reaction, decantation was repeated with sufficient pure water, the unreacted component, excess sulfuric acid and sulfuric acid formed by the reaction were removed, solid-liquid separation was performed, and dried powder was obtained after drying with a vacuum dryer. .
The obtained dry powder is heat-treated (fired) at 650 ° C. for 30 minutes in a rotary tube furnace, and silica / titania-coated magnetite powder C₂Got.
This two-layer coating powder C₂Was yellowish red, and the maximum reflection peak was 607 nm.
[0081]
(Formation of third layer silica film)
40 g of silica / titania coated magnetite powder C₂On the other hand, as in the first layer, 3751 g of buffer solution 3 (pH: about 9.0) prepared in advance and 313 ml of pure water were added and 28 kH was added._ZFurther, while applying ultrasonic waves in a 600 W ultrasonic bath, the mixture was further dispersed with stirring in the buffer solution 3 containing magnetite powder. To this, 1563 ml of an aqueous sodium silicate solution prepared in advance was gradually added at 2.67 ml / min to deposit a silica film on the surface.
After the addition of the aqueous sodium silicate solution, the reaction was further continued for 2 hours to react all unreacted raw materials.
After completion of the film forming reaction, the slurry containing the silica film powder was repeatedly decanted with sufficient water and washed.
After washing, the silica membrane powder is put into a vat, separated and separated, and the upper liquid is discarded._ThreeGot.
[0082]
(Fourth layer titania film formation)
40 g of the above powder C_ThreeIn contrast, 3751 ml of buffer solution 4 and 313 ml of pure water are prepared, and powder C is added to the mixture._ThreeWas sufficiently dispersed in an ultrasonic bath while being ultrasonically dispersed in the same manner as in the silica film formation. Thereafter, 1563 ml of a titanyl sulfate aqueous solution (TiO 2) prepared in advance while keeping the temperature of the solution at 50 to 55 ° C.₂, 15 w%) was gradually added dropwise at a constant rate of 1.25 ml / min, and solid-phase fine particles were precipitated, and the addition was terminated while the liquid was slightly clouded.
After completion of dropping, the reaction was further continued for 3 hours, and the unreacted portion was gradually precipitated as solid phase fine particles, and the fine particles were taken into the film.
After completion of the film-forming reaction, decantation was repeated with sufficient pure water, the unreacted component, excess sulfuric acid and sulfuric acid formed by the reaction were removed, solid-liquid separation was performed, and dried powder was obtained after drying with a vacuum dryer. .
[0083]
The obtained dry powder is heat-treated (fired) at 650 ° C. for 30 minutes in a rotary tube furnace, and silica / titania-coated magnetite powder C_FourGot.
This 4-layer coating powder C_FourWas light red and the maximum reflection peak was 718 nm.
[0084]
(Preparation of red ink composition)
The silica / titania-coated magnetite powder C thus obtained_Four, 30 g is dispersed in a solution in which 2.5 g of an acrylic polymer (Technobit, manufactured by Kulzer) is dissolved in 80 g of ethanol in advance, and then 20 g of titanium oxide (silicone hydrophobized product: color developing material) and hydroxypropylcellulose. The mixed liquid added with 2 g was subjected to a dispersion treatment for 8 hours with a zirconia ball mill to obtain a paint dispersion liquid CL of a red color material composition.
[0085]
(Coating and spectral properties)
Dispersion liquid CL of the fluorescent pigment composition was applied to art paper with a blade coater. The coating amount (after drying) of the red color material composition is 60 g / m²It was.
After drying, the color of the obtained coated paper C was bright red with a maximum reflection peak wavelength of 718 nm and a reflectance of 67%. In addition, 1m of this coating basket C²Magnetization at 1 kOe per hit is 720 emu / cm²Met.
Table 3 shows the refractive index and film thickness of the first to fourth layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0086]
[Table 3]

[0087]
[Example 4] (Red color material composition 4 using magnetic material, three-layer coating by hydrolysis of metal alkoxide)
(Formation of first layer silica film)
20 g of BASF carbonyl iron powder (average particle size 1.8 μm, magnetization at 10 kOe is 203 emu / g) was dispersed in a solution of 22.8 g of silicon ethoxide dissolved in 158.6 g of ethanol in advance. While stirring, a previously prepared mixed solution of 22.8 g ammonia water (29%) and 30.4 g deionized water was added. After the addition, the reaction was allowed to proceed at room temperature for 5 hours. After the reaction, it was diluted and washed with sufficient ethanol, filtered, and dried in a vacuum dryer at 110 ° C. for 3 hours. After drying, heat treatment (baking) is performed at 800 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, cooled, and silica-coated iron powder D₁Got.
[0088]
(Formation of second-layer titania film)
In a separable flask, 20 g of the above silica-coated powder D₁Was dispersed in a solution in which 17.9 g of titanium isopropoxide was added in advance to 198.3 g of ethanol, and then 30.4 g of pure water prepared in advance was added to 47.9 g of ethanol while stirring. The mixed solution was added dropwise over 1 hour. After dropping, the reaction was allowed to proceed at room temperature for 5 hours. After the reaction, it is diluted and washed with sufficient ethanol, filtered, dried in a vacuum dryer at 110 ° C for 3 hours, and silica / titania coated iron powder D₂Got.
When the titania layer after drying was observed for the particle state in the layer using a transmission electron microscope, titanium oxide solid phase fine particles of 1 to 10 nm were observed, but there were no voids between the particles uniformly inside the film. It was filled.
This titanium oxide film had an average film thickness of 93 nm, a peak wavelength of a spectral reflection curve at 750 nm, and was light red.
[0089]
(Formation of third layer silica film)
20g of silica / titania coated iron powder D₂Was dispersed in a solution in which 3.0 g of silicon ethoxide was dissolved in 156.8 g of ethanol in advance, and then 3.0 g of ammonia water (29%) and 4.0 g prepared in advance while stirring. A mixed solution of deionized water was added. After the addition, the reaction was allowed to proceed at room temperature for 1 hour. After the reaction, it was diluted and washed with sufficient ethanol, filtered, and dried in a vacuum dryer at 110 ° C. for 3 hours. After drying, heat treatment (baking) is further performed at 500 ° C. for 30 minutes in a nitrogen atmosphere, cooling, and silica / titania coated iron powder D_ThreeGot.
When the state of particles in the titania layer after the heat treatment was observed using a transmission electron microscope, titanium oxide crystallized fine particles of 10 to 150 nm were observed, and voids of about 10 to 50 nm were observed between the particles. It was.
However, the silica layer was dense, free of particles and smooth. Furthermore, voids existed at the interface with titania.
[0090]
This powder D_ThreeThe maximum reflection peak wavelength was 770 nm, the magnetization at a magnetic field of 1 kOe was 129 emu / g, and the color was pale red.
From this Example 4, from the presence or absence of heat treatment (firing), titania particles crystallized, and voids between the particles and the silica film accompanying the particle formation are seen, due to the scattering reflection effect accompanying these particle formation, It seems that redness was achieved.
In addition, the red color material powder of Example 4 is characterized in that a dense film is formed on the final coating layer. The gap is covered with a dense film that does not affect interference and scattering, and is not limited to the high refractive index film as in the final layer so far. In the prior art, when the obtained powder is used as a pigment for toner, paint, etc., resin or vehicle enters the gap, and the difference in refractive index from interference or scattering particles decreases, resulting in a decrease in Fresnel reflectance. was there. However, by covering the voids of the particle-constituting film with the final layer being a dense film that does not affect interference and scattering, it is possible to prevent the above-mentioned scattering reflection from being lowered.
[0091]
(Adhesive resin layer, polystyrene composite powder)
100 g of styrene monomer and red color material multilayer coating powder (silica / titania coated iron powder D_Three) 100 g and 10 g of the oleophilic titanium oxide were dispersed with a high-speed stirrer until they were dispersed.
A solution of this styrene monomer and particles dissolved in 500 g of distilled water of sodium n-dodecyl sulfate was added at 70 ° C. while stirring at high speed, and stirred until the emulsified particles were sufficiently finely divided.
10 g of 10% ammonium persulfate aqueous solution was added thereto, and the mixture was reacted for 4 hours with stirring.
After completion of the reaction, dilute with 2 liters of distilled water, discard the top solution by decantation and collect the precipitate. The precipitate was dried on filter paper to obtain red polystyrene-coated powder D.
The obtained powder of red color material composition D was spherical, the magnetization at a magnetic field of 1 kOe was 18.5 emu / g, and the magnetization at a magnetic field of 10 kOe was 61.5 emu / g.
Table 4 shows each refractive index, film thickness, peak wavelength of the spectral reflection curve of the coating powder, and reflectance at the peak wavelength.
[0092]
[Table 4]

[0093]
[Example 5] (Red color material composition 5 using magnetic material, 5-layer coating by hydrolysis of metal alkoxide)
(Formation of first layer silica film)
20 g of BASF carbonyl iron powder (average particle size 1.8 μm, magnetization at 10 kOe is 203 emu / g) was dispersed in a solution of 16.1 g of silicon ethoxide dissolved in 158.6 g of ethanol in advance. While stirring, a previously prepared mixed solution of 16.1 g of ammonia water (29%) and 16.1 g of deionized water was added. After the addition, the reaction was allowed to proceed at room temperature for 5 hours. After the reaction, it was diluted and washed with sufficient ethanol, filtered, and dried in a vacuum dryer at 110 ° C. for 3 hours. After drying, using a rotary tube furnace, heat treatment (baking) is performed at 600 ° C. for 30 minutes in a nitrogen atmosphere, cooling, and silica-coated iron powder E₁Got.
[0094]
(Formation of second-layer titania film)
In a separable flask, 20 g of the above silica-coated powder E₁Was dispersed in a solution obtained by adding 17.9 g of titanium isopropoxide to 198.3 g of ethanol in advance, and then 31.0 g of pure water prepared in advance was added to 47.9 g of ethanol while stirring. The mixed solution was added dropwise over 1 hour. After dropping, the reaction was allowed to proceed at room temperature for 3 hours. After the reaction, it is diluted and washed with sufficient ethanol, filtered, dried in a vacuum dryer at 100 ° C. for 8 hours, and silica / titania coated iron powder E₂Got.
This titanium oxide film had an average film thickness of 96 nm, a peak wavelength of a spectral reflection curve at 760 nm, and was yellowish red.
[0095]
(Formation of third layer silica film)
20g of silica / titania coated iron powder E₂Was dispersed in a solution in which 29.7 g of silicon ethoxide was dissolved in 158.6 g of ethanol in advance, and then 29.7 g of aqueous ammonia (29%) and 39.6 g prepared in advance while stirring. A mixed solution of deionized water was added. After the addition, the reaction was allowed to proceed at room temperature for 5 hours. After the reaction, it was diluted and washed with sufficient ethanol, filtered, and dried in a vacuum dryer at 110 ° C. for 3 hours. After drying, using a rotary tube furnace, heat treatment (baking) is performed at 500 ° C. for 30 minutes in a nitrogen atmosphere, cooling, and silica / titania coated iron powder E_ThreeGot.
[0096]
(Fourth layer titania film formation)
In a separable flask, 20 g of the above silica-coated powder E_ThreeWas dispersed in a solution obtained by adding 23.2 g of titanium isopropoxide to 198.3 g of ethanol in advance, and then 39.6 g of pure water prepared in advance was added to 60.0 g of ethanol while stirring. The mixed solution was added dropwise over 1 hour. After dropping, the reaction was performed at room temperature for 4 hours. After the reaction, it is diluted and washed with sufficient ethanol, filtered, dried in a vacuum dryer at 100 ° C. for 8 hours, and silica / titania coated iron powder E_FourGot.
[0097]
(Fabrication of the fifth layer silica film)
20g of silica / titania coated iron powder E_FourWas dispersed in a solution prepared by dissolving 2.5 g of silicon ethoxide in 158.6 g of ethanol in advance, and then 2.5 g of ammonia water (29%) and 3.0 g prepared in advance while stirring. A mixed solution of deionized water was added. After the addition, the reaction was allowed to proceed at room temperature for 5 hours. After the reaction, it was diluted and washed with sufficient ethanol, filtered, and dried in a vacuum dryer at 110 ° C. for 3 hours. After drying, using a rotary tube furnace, heat treatment (heat treatment) at 600 ° C. for 30 minutes in a nitrogen atmosphere, cooling, silica / titania coated iron powder E_FiveGot.
This iron powder E_FiveHad a peak wavelength of the spectral reflection curve at 760 nm and was light red. The magnetization at a magnetic field of 10 kOe was 82 emu / g.
[0098]
(Preparation of red ink composition)
Silica / titania coated iron powder E thus obtained_Five, 30 g is dispersed in a solution in which 2.5 g of an acrylic polymer (Technobit, manufactured by Kulzer) is dissolved in 80 g of ethanol in advance, and then 20 g of titanium oxide (silicone hydrophobized product: color developing material) and hydroxypropylcellulose. The mixed liquid added with 2 g was subjected to a dispersion treatment for 8 hours with a zirconia ball mill to obtain a coating dispersion EL of a red color material composition.
[0099]
(Coating and spectral properties)
The dispersion EL of the fluorescent pigment composition was applied to art paper with a blade coater. The coating amount (after drying) of the red color material composition is 60 g / m²It was.
After drying, the color of the resulting coated paper E was 755 nm at the peak wavelength and became bright red.
Further, the magnetization of the coating rod E with a magnetic field of 1 kOe is 1480 emu / m.²The magnetization at a magnetic field of 10 kOe is 4920 emu / m²Met.
Table 5 shows the refractive indexes and film thicknesses of the first to fifth layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0100]
[Table 5]

[0101]
[Example 6] (Red color material composition 6 using dry film magnetic substance, aqueous three-layer coating)
(Film formation of the first layer titania film)
1 kg of iron powder with an average particle size of 1.8 microns and 1.5 kg of titanium oxide particles with an average particle size of 0.2 microns are dry mixed and pulverized three times for 5 minutes using a Hosokawa Micron mechano-fusion device to form a film. The titanium oxide-coated iron powder with improved brightness₁Got.
[0102]
(Formation of second layer silica film)
Into the same buffer solution 3,214 ml as in Example 1 prepared in advance, 181 ml of pure water prepared in advance was mixed, and F₁After adding 10 g and mixing well, SiO₂145 ml of a water glass solution having a mixing ratio of 10 wt% was gradually added dropwise with stirring over 3 hours, and the reaction was continued for 1 hour. After the reaction, solid-liquid separation is performed by decantation, and the powder is vacuum-dried and then dried for 8 hours, followed by heat treatment at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, and the silica / titania film-coated iron powder F₂Got.
[0103]
(Third layer titania film formation)
Furthermore, silica / titania film coated iron powder F₂After adding 4484 ml of buffer solution to 4 g and sufficiently dispersing, titanyl sulfate TiO 2₂A 15% aqueous solution, 38 ml, was added dropwise over 4 hours, and after the addition, the mixture was reacted for 1 hour to remove unreacted materials. After the reaction, solid-liquid separation is performed by decantation, and the powder is dried in a vacuum dryer for 8 hours, and then heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace to produce a silica / titania film coated iron powder F_ThreeGot.
This powder had a peak of 728 nm, a reflectance of 44%, and a deep red color. Further, the magnetization of this powder with a magnetic field of 1 kOe was 31.4 emu / g, and the magnetization of 10 kOe was 984 emu / g.
[0104]
(Toner)
After mixing a solution of 0.3 g of oil red in 30 ml of xylene with 100 g of styrene monomer, F obtained in advance_Three100 g of the lipophilic powder and 10 g of titanium oxide were added and mixed uniformly.
Next, this mixture of styrene monomer and particles was put into an aqueous solution in which 3 g of sodium dodecyl sulfate was dissolved, and then stirred at 10,000 rpm with a homogenizer, and further maintained at 70 ° C. while stirring at 5,000 rpm. Thereafter, 10 g of a 10% ammonium persulfate aqueous solution was added and reacted for 3.5 hours.
Then, solid content was filtered, and it wash | cleaned repeatedly 3 times with warm water, and obtained the red polystyrene coating powder FP. The magnetic field magnetization of this powder at 1 kOe was 18.64 emu / g, and the magnetization at 10 kOe was 46.74 emu / g.
Table 6 shows the refractive index and film thickness of the first to third layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0105]
[Table 6]

[0106]
[Example 7] (Blue color material composition 7 using plate magnetic material, metal alkoxide hydrolysis and water-based three-layer coating) (ink)
(Formation of first layer silica film)
To 10 g of plate-like Ba ferrite having an average particle diameter of 2.8 microns, 79.5 g of ethanol is added and dispersed sufficiently, and then 11.4 g of silicon ethoxide is added and mixed. Further, 11.2 g of water, ammonia 15.2 g of water was added and reacted for 3 hours while stirring at room temperature. After the reaction, solid-liquid separation is performed by decantation, and the powder is vacuum-dried and then dried for 8 hours, followed by heat treatment at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace.₁Got.
[0107]
(Second layer titanium film coating coloring)
Silica film coated Ba ferrite particles G₁After 10 g was sufficiently dispersed in 159 g of ethanol, 8.9 g of titanium isopropoxide was added and mixed well, and then a prepared mixed solution of 15.2 g of water and 30 g of ethanol was added dropwise to react for 5 hours. I let you. After the reaction, solid-liquid separation is performed by decantation, and the powder is vacuum-dried and then dried for 8 hours, followed by heat treatment at 650 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, and the silica / titania film coated Ba ferrite particles G₂Got.
This powder had a peak of 780 nm, a reflectance of 42%, and a deep red color. The 10 kOe magnetization of this powder was 13.6 emu / g, and the residual magnetization was 8.6 emu / g.
[0108]
(3rd layer scattering film coating)
G prepared in advance₂Similarly, 875 ml of buffer solution 4 prepared in advance was mixed with 10 g of powder, and 5 g of titanium oxide (rutile type) powder particles having an average particle size of 0.2 microns were added and mixed well. The mixture was stirred for 1 hour while stirring 274 ml of water glass solution. The decantation was repeated 20 times and sufficiently washed, and then dried at 120 ° C. for 8 hours with a dryer. The dried powder is heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, and the silica-based / titania scattering film-coated Ba-based ferrite particles G_ThreeGot.
This powder had a peak of 780 nm, a reflectance of 67%, and a light blue color.
The 10 kOe magnetization of this powder was 10.0 emu / g, and the remanent magnetization was 6.6 emu / g.
Table 7 shows the refractive index, film thickness, peak wavelength of the spectral reflection curve of the coating powder, and reflectivity at the peak wavelength of the first to third layers.
[0109]
[Table 7]

[0110]
(Ink)
G above_ThreeTo 30 g of powder, 1.5 g of acrylic resin and 2.3 g of hydroxypropyl cellulose were dispersed in 80 g of an ethanol solution in advance, and liquid GL was obtained in which the viscosity was increased by evaporating alcohol while stirring.
The GL was striped on a plastic film for thermal transfer using a small-sized printing machine PG10 manufactured by RISO.
[0111]
(Applied material)
When this film was scanned with a detector equipped with a magnetic head after drying, the magnetic powder G₃A magnetic reaction was detected in the printed part, but no magnetic reaction occurred in the blank part. The coating was red when viewed from above, but when viewed from an oblique angle of 30 degrees, it looked yellow and showed multicolor.
[0112]
[Example 8] (Red color material composition 8 using plate mineral, three-layer coating by metal alkoxide hydrolysis) (Coating)
(First layer coating coloring)
After fully dispersing 20 g of plate-like muscovite powder having an average particle size of 12 microns in 160 g of ethanol, 9 g of titanium isopropoxide was added and mixed well, and then 15.5 g of water prepared in advance and 30 g of ethanol were added. The mixed solution was dropped and reacted for 5 hours. After the reaction, solid-liquid separation is performed by decantation, and the powder is air dried and then dried for 8 hours, and then heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace.₁Got.
The powder had a peak of 785 nm, a reflectance of 42%, and a deep red color.
[0113]
(Second layer coating)
Titania coated platy muscovite powder H₁After fully dispersing 20 g in 80 g of ethanol, 15.1 g of silicon ethoxide is added and mixed, and then 19.9 g of water and 15.1 g of aqueous ammonia are added and reacted for 3 hours while stirring at room temperature. I let you. After the reaction, solid-liquid separation is performed by decantation, and the powder is vacuum-dried and then dried for 8 hours, followed by heat treatment at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, and silica / titania-coated plate-like muscovite powder H₂Got.
[0114]
(3rd layer colored film coating)
Silica / titania-coated platy muscovite powder H₂, 20 g was sufficiently dispersed in 160 g of ethanol, and then 15.1 g of titanium isopropoxide was added and mixed well. Then, a prepared mixed solution of 15.1 g of water and 30 g of ethanol was added dropwise for 5 hours. I let you. After the reaction, solid-liquid separation is performed by decantation, and the powder is vacuum-dried and then dried for 8 hours, followed by heat treatment at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace, and the silica / titania film-coated plate-like muscovite powder H_ThreeGot.
The powder had a peak of 785 nm, a reflectance of 65%, and a pale red color.
Table 8 shows the refractive index, film thickness, peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength of the first to third layers.
[0115]
[Table 8]

[0116]
(Application)
Above powder H_ThreeWhile stirring and dispersing 15 g, an ethanol solution (ethanol 50 g) in which 2.2 g of acrylic resin was dissolved was added and dissolved.
When a part of the solvent is dispersed and the viscosity is increased, the dispersion is spread on a flat glass plate and uniformly adhered to a rubber roller, and then the viscous fluid HL is applied to the A4 plate thermal transfer film and left for one day. Dried.
The obtained powder coated film has a pale red band when viewed vertically, and when the angle of viewing is changed by tilting the plate toward the sun, the color is pale red when the sun is on the back (almost vertical light). However, when the angle between the sun and the plate (incident angle) was 40 degrees from the plate, the color was yellow and pleochroism was observed.
This property can be used for polychromatic display media, cosmetics and decorations, or flip-flop methods.
[0117]
[Example 9] (Red color material composition 9 using plate-like conductor, three-layer coating by metal alkoxide hydrolysis) (Paint)
(First layer coating coloring)
After 18 g of plate-like aluminum powder having an average particle size of 12 microns is sufficiently dispersed in 160 g of ethanol, 9.0 g of titanium isopropoxide is added and mixed well, and further 15.5 g of water and 160 g of ethanol prepared in advance. The mixed solution was added dropwise and reacted for 5 hours. After the reaction, solid-liquid separation was performed by decantation, and the powder was vacuum-dried and then dried for 8 hours, and then heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace.₁Got.
This powder had a peak of 780 nm, a reflectance of 42%, and a deep red color.
[0118]
(Second layer coating)
Titania coated plate-like aluminum powder I₁, 18 g was sufficiently dispersed in 15.1 g of ethanol, 8.1 g of silicon ethoxide was added and mixed, and further, 19.9 g of water and 15.1 g of aqueous ammonia were added, and the mixture was stirred at room temperature. Reacted for hours. After the reaction, solid-liquid separation was performed by decantation, and the powder was vacuum dried and then dried for 8 hours, and then heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace to obtain silica / titania-coated plate-like aluminum powder I₂Got.
[0119]
(3rd layer colored film coating)
Silica / titania coated plate-like aluminum powder I₂, 18 g was sufficiently dispersed in 160 g of ethanol, 11.8 g of titanium isopropoxide was added and mixed well, and then a prepared mixed solution of 20.1 g of water and 160 g of ethanol was added dropwise for 5 hours. I let you. After the reaction, solid-liquid separation was performed by decantation, and the powder was vacuum dried and then dried for 8 hours, and then heat-treated at 500 ° C. for 30 minutes in a nitrogen atmosphere using a rotary tube furnace._ThreeGot.
This powder had a peak of 785 nm, a reflectance of 68%, and a light red color.
Table 9 shows the refractive indexes and film thicknesses of the first to third layers, the peak wavelength of the spectral reflection curve of the coating powder, and the reflectance at the peak wavelength.
[0120]
[Table 9]

[0121]
(Application)
Prepare 7 pieces of double-sided adhesive tape with a width of 3mm and a length of 57mm on a white vinyl chloride plate with a long side of 80mm, a single side of 57mm, and a thickness of 1.5mm. One piece in the center parallel to the single plate side After pasting, it was pasted in parallel at intervals of 3 mm from the central strip tape. Then I_ThreeWas lowered evenly on the board on which this tape was applied. Further, this white vinyl chloride plate was placed horizontally on an iron plate having a side of 10 cm and a thickness of 1 cm, and the same plate was placed on top and sandwiched between two sheets. A 1 kg weight was placed on the center of the plate and left for 1 hour.
After 1 hour, the plate was removed, and the powder that did not adhere was removed with a brush.
When the obtained plate was viewed vertically, a light red band was observed, and pleochroism was observed as in Example 8.
[0122]
(Physical properties)
As a result of scanning a search coil equipped with a Wheatstone bridge, a power source and an ammeter perpendicularly to a single side of the plate, the ammeter changed in the coated portion, but no change was observed in the non-coated portion. Detection by electric field is also possible.
This property can be used for polychromatic display media, cosmetics and decorations, or flip-flop methods.
[0123]
As is clear from Tables 1 to 9, the red color material composition of each example of the present invention obtained satisfactory results. In addition, since the titania coating layer having voids by crystallizing titania particles is provided in two layers (second layer and fourth layer) rather than one layer (second layer), a high degree of redness is achieved.
[0124]
【The invention's effect】
As described above, the red color material composition of the present invention can be produced at a lower production cost than the alkoxide method by using water as a solvent in the film-forming reaction in the production of the contained red powder. The effect of forming a film is obtained.
In addition, at least one layer of the coating film on the surface of the base particle is a film composed of crystallized fine particles and an aggregate of crystallized fine particles having voids between the crystallized fine particles (hereinafter simply referred to as crystallized fine particle constituting film). Contains a functional powder of red color tone that increases the refractive index difference between the crystallized particle surface and voids, causes light scattering and reflection, enhances the reflection effect, and has excellent brightness. It has become possible to provide a red color material composition.
[0125]
The red color material composition of the present invention obtained as described above has a function of maintaining the characteristics (for example, magnetic characteristics) of the base particles at a high level when a magnetic material is used as the base of the contained red powder. Powder, for example, a red magnetic toner that can perform an excellent composite function even in a one-component development system, and excellent magnetic properties. Also, multicolored and reflective or transmitted colors are used for decorative items, ceramics, porcelain, glassware, paintings and other crafts and arts, books, automobiles, bicycles, etc. Water-based ink, toner, paint, cosmetics, and titanium oxide film with catalytic action, which has excellent weather resistance and environmental cleanability such as air and water, and has both substrate characteristics and film characteristics. It can be applied to red multifunctional inks, toners and paints. In particular, printing inks as anti-counterfeiting pigment compositions by combining two or more of the above functions with the functions of magnetism, electric field, color, particle shape, fluorescence emission, phosphorescent emission, specific ultraviolet ray reflection absorption and specific infrared reflection absorption In addition, it is possible to provide a red color material composition capable of forming a desired image as a toner on a support medium and visually discriminating and discriminating by an apparatus and an efficient manufacturing method thereof.
In addition to having these excellent functions, if a conductor or dielectric is used as the base of the contained red powder, it reacts due to external factors of the electric field, thereby adding additional forces such as moving force, rotation, motion, heat generation, etc. It is possible to provide a red color material composition that retains the function of producing an action and an efficient production method thereof, which greatly contributes to the industry.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an example of a red powder contained in a red color material composition of the present invention.
FIG. 2 is an enlarged cross-sectional view of a crystallized fine particle constituting film 2 included in a red powder contained in the red color material composition of FIG.
[Explanation of symbols]
1 Base particles
2 Crystallized fine particle composition film
3 Crystallized fine particles
4 Ultra fine particles

Claims (30)

It is formed by forming solid phase fine particles in the reaction solution by reaction of the metal salt on the surface of the substrate particles by reaction of the metal salt in an aqueous solvent , and incorporating the solid phase fine particles into the coating film, A red color material composition comprising a red powder having a reflection spectrum having at least one coating film configured as an aggregate of crystallized fine particles having voids and having a peak between 600 and 800 nm. The coating film formed by the reaction of a metal salt in an aqueous solvent of the red powder, red colorant composition to that請 Motomeko 1 wherein characterized in that the condition is satisfied of the formula: .
Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film d: Film thickness m: Natural number λ: Peak wavelength of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient)   2. The red color material composition according to claim 1, wherein the coating film on the surface of the base particles of the red powder is a multilayer film.   4. The red color material composition according to claim 3, wherein each film of the red powder multilayer film is formed by a reaction of a metal salt in an aqueous solvent. 4. The red color material composition according to claim 3, wherein each film of the red powder multilayer film satisfies the following formula. 5.
Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film d: Film thickness m: Natural number λ: Peak wavelength of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient) The coating film configured as an aggregate of crystallized fine particles having voids is capable of imparting lightness by scattering and reflecting light generated between the surface of the crystallized fine particles and the voids. The red color material composition according to claim 1. 2. A dense coating film composed of ultrafine particles capable of closing the voids on the surface of the coating film configured as an aggregate of crystallized fine particles having voids. The red color material composition according to 1. 2. The red color material composition according to claim 1, wherein the coating film configured as an aggregate of crystallized fine particles having voids is a high refractive index film. The red color material composition according to claim 7, wherein the dense film is a silica film. 2. The red color material composition according to claim 1, wherein the red color material composition is formed by firing solid phase fine particles in the coating film. The red color material composition according to claim 1, wherein the reaction solution is an aqueous solution. Before the firing, the coating film into which the solid phase fine particles have been incorporated is coated with ultrafine particles that can form a dense film that closes the voids on the surface of the coating film. The red color material composition according to claim 10. The red color material composition according to claim 1, wherein the red powder is dispersed in a dispersion medium containing at least a binding resin. The red color material composition according to claim 1, further comprising an adhesive resin layer on the red powder. The red color material composition according to claim 14, wherein the adhesive resin layer contains an extender pigment. In the method for producing a red color material composition containing a red powder, a metal salt in an aqueous solvent is formed on the surface of the base particle so that the red powder exhibits a reflection spectrum having a peak between 600 and 800 nm. Formed by forming solid phase fine particles in the reaction solution by reaction and incorporating the formed solid phase fine particles, forming at least one coating film configured as an aggregate of crystallized fine particles having voids A method for producing a red color material composition. The method for producing a red color material composition according to claim 16, wherein the coating film formed by the reaction of a metal salt in an aqueous solvent is formed so as to satisfy the following formula.
Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient) The method for producing a red color material composition according to claim 16, wherein the coating film formed on the surface of the base particle is a multilayer film. 19. The method for producing a red color material composition according to claim 18, wherein each film of the multilayer film is formed by a reaction of a metal salt in an aqueous solvent. 19. The method for producing a red color material composition according to claim 18, wherein all the films of the multilayer film are formed so as to satisfy the condition of the following formula.
Nd = mλ / 4
[Where N = n + iκ (i represents a complex number)
n: Refractive index of the material constituting the film
d: Film thickness
m: natural number
λ: wavelength of the peak of the reflection spectrum of the powder (where λ is 600 to 800 nm)
(κ: damping coefficient) The coating film configured as an aggregate of crystallized fine particles having voids is formed so that brightness can be imparted by light scattering and reflection generated between the surface of the crystallized fine particles and the voids. The manufacturing method of the red color material composition of 16. 17. The red color according to claim 16, wherein a dense film is formed on the surface of the coating film configured as an aggregate of crystallized fine particles having voids, with ultrafine particles capable of closing the voids on the surface. Manufacturing method of material composition. 17. The method for producing a red color material composition according to claim 16, wherein the coating film configured as an aggregate of crystallized fine particles having voids is a high refractive index film. The method for producing a red color material composition according to claim 22, wherein the dense film is a silica film. The method for producing a red color material composition according to claim 16, wherein the solid phase fine particles are formed by firing after being taken into the coating film. The method for producing a red color material composition according to claim 25, wherein the reaction solution is an aqueous solution. Before performing the firing, the coating film into which the solid phase fine particles have been incorporated is coated with ultrafine particles that can form a dense film that closes the voids on the surface of the coating film, The method for producing a red color material composition according to claim 25. The method for producing a red color material composition according to any one of claims 16 to 27, wherein the red powder is dispersed in a dispersion medium containing at least a binding resin. The method for producing a red color material composition according to any one of claims 16 to 28, wherein an adhesive resin layer is provided on the red powder. 30. The method for producing a red color material composition according to claim 29, wherein the adhesive resin layer contains an extender pigment.

Images