JP2004189852A

JP2004189852A - Stabilized copper-phthalocyanine pigment, method for producing the same, pigment-colored composition and colored article

Info

Publication number: JP2004189852A
Application number: JP2002358445A
Authority: JP
Inventors: Yoshiyuki Zama; 義之座間; Atsushi Nogami; 敦野上; Hisao Okamoto; 久男岡本; Naoki Hirata; 直毅平田; Michiei Nakamura; 道衛中村
Original assignee: Dainichiseika Color and Chemicals Mfg Co Ltd
Current assignee: Dainichiseika Color and Chemicals Mfg Co Ltd
Priority date: 2002-12-10
Filing date: 2002-12-10
Publication date: 2004-07-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stabilized copper-phthalocyanine pigment having extremely reduced content of free copper exerting bad influence such as damage of the preservation stability of a coating material or ink, acceleration of oxidative deterioration of an olefin resin or the like, acceleration of foaming rate of an azodicarbonamide-based foaming agent which is a high-temperature foaming agent for a plastic; and to provide a method for producing the pigment. <P>SOLUTION: The stabilized copper-phthalocyanine pigment has ≤200 ppm content of the free copper contained in the pigment. The pigment is produced by completely dissolving a crude copper-phthalocyanine in concentrated sulfuric acid, adding the sulfuric acid solution to water, ice water or the like to precipitate the copper-phthalocyanine, filtering the precipitated product and washing the filtered product with water to reduce the content of the free copper contained in the pigment to ≤200 ppm, and subjecting the obtained pigment to crystal-converting treatment to provide the pigment having a stabilized crystal form. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、精製された不安定型銅フタロシアニン顔料から安定型に結晶転移させた遊離銅の含有量が著しく低減された安定型銅フタロシアニン顔料、その製造方法、およびそれを用いた顔料着色組成物および着色物品に関する。更に詳しくは顔料中に含まれる全遊離銅の含有量が２００ｐｐｍ以下の安定型銅フタロシアニン顔料、その製造方法、およびそれを用いた顔料着色組成物および着色物品に関するものである。
【０００２】
【従来の技術】
従来、安定型銅フタロシアニン顔料は鮮明で高堅牢性の緑味青色の顔料として、各種印刷インキのシアン色インキ、フルカラー電子写真複写機やフルカラープリンターのシアン色トナー、インクジェットプリンターのシアン色インキ、筆記具類の青色やスカイブルー色に使用する顔料として、あるいは塗料やプラスチックの青色の着色剤として賞用されてきている。
【０００３】
この安定型銅フタロシアニン顔料は、ポルフィリン環を配位子とし、銅を中心金属とする錯体顔料である。銅フタロシアニンの代表的製造方法であるワイラー（Ｗｙｌｅｒ）法では、常圧法、加圧法に拘わらず無水フタル酸、尿素と塩化第一銅等の銅塩が使用され、フタロジニトリル法では、フタロジニトリルと銅塩が使用される。また、縮合触媒としては、モリブデン酸アンモニウム、リンモリブデン酸等が使用される。
【０００４】
着色剤等に使用する銅フタロシアニン顔料（以下、単に顔料と称する場合がある。）は、通常上記の製造方法により顔料クルードを合成した後、ソルトミリング、ソルベントソルトミリングやアシッドスラリー法により顔料化処理（ピグメンテーション）することで製造されている。これらの顔料化処理は、いずれも顔料クルードの微粒子化および安定型銅フタロシアニンへの結晶形の変換を目的としたものであり、錯体の中心金属として顔料中に取り込まれなかった未反応の銅塩（本発明において「遊離銅」と称する場合がある）をある程度しか取り除くことができず、遊離銅が顔料粒子中に残存することは避けられないことである。
【０００５】
このように、これらの方法で得られた顔料は粒子中に遊離の銅を含有していることから、顔料を着色剤に加工するに際し、種々の分散媒体中に分散されたとき、分散条件により磨砕（破砕）された顔料粒子中から未反応の銅が遊離析出してくる。このような形で析出した遊離銅は着色剤として用いられた銅フタロシアニンと共に分散媒体中に分散され、例えば分散媒体であるポリオレフィン樹脂等の酸化を促進したり、耐熱性に対し悪影響を与えることがある。また、負電荷電子写真用トナーの顔料として銅フタロシアニンを用いた場合、高湿環境下では帯電量が低下し、画像濃度が変化したり、カブリが発生する等の不具合が生じることがある。この不具合は、該顔料中の遊離銅の含有量と関係があり、該顔料中の遊離銅の含有量を２０００ｐｐｍ以下とした該顔料の使用が提案されている（特許文献１）。また、銅は重金属に属しているので、環境にやさしい材料が優先される時代には好ましくない影響を与える可能性がある。そこで時代の要請からも、顔料中に含まれる遊離銅の含有量が極めて少ない安定型銅フタロシアニン顔料が要望されている。
【０００６】
特許文献１に示されている該顔料中の遊離銅の含有量を減らす方法は、合成後の反応生成物から溶媒を減圧留去し、残留物（粗製顔料）を水や希硫酸等の酸で十分に洗浄したり、粗製該顔料を微細化する顔料化工程で水や酸で十分に洗浄する方法である。しかしながら、これらの方法では上記の残留物を水で洗浄した場合の遊離銅含有量（顔料を硫酸に溶解、この溶液を水に加えて顔料の結晶を析出させ、ろ別、洗浄し、ろ液と洗浄液との混合液中の銅を原子吸光法により求めた）１２０００ｐｐｍを２０００ｐｐｍに減らすことができることが特許文献１には記載されているが、上記数値以下に遊離銅含有量を減らした該顔料およびその場合の遊離銅含有量の低減方法は特許文献１には全く示されていない。
【０００７】
【特許文献１】
特開平１１−７１６１号公報
【０００８】
【発明が解決しようとする課題】
遊離銅は塗料やインキの保存安定性を損ない、ポリオレフィン樹脂等の耐熱性劣化を促進する傾向があり、遊離銅の少ない安定型銅フタロシアニンが要望されている。また、遊離銅は、プラスチックの高温発泡剤として使用されているアゾジカルボアミド系発泡剤の発泡速度を速める傾向があるため、銅フタロシアニン顔料を用いた青色プラスチック発泡体と他の顔料を用いた別の有彩色プラスチック発泡体との間で発泡速度に差が生じ、発泡状態が不均一となる等の不具合が発生する。また、重金属である銅は、環境問題の面からも可能な限り含有量を零に近くすることが好ましい。
本発明は上記の事情に鑑みてなされたものであり、本発明の目的は遊離銅の含有量が著しく低減された安定型銅フタロシアニン顔料およびその製造方法を提供することである。
【０００９】
【課題を解決するための手段】
本発明者らは上述の目的を達成すべく鋭意研究の結果、銅フタロシアニン顔料を濃硫酸に完全に溶解し、水等に析出させる工程を経て、ろ過洗浄することにより、顔料粒子中に含有する遊離銅を著しく低減できることを見いだし、この知見に基づいて本発明を完成させるに至った。
【００１０】
本発明によれば、顔料中に含まれる遊離銅の含有量が２００ｐｐｍ以下であることを特徴とする安定型銅フタロシアニン顔料が提供される。
また、本発明によれば、銅フタロシアニン顔料クルードを濃硫酸に完全に溶解し、この硫酸溶液を水または氷水に加えて、あるいは氷上に加えて銅フタロシアニンの結晶を析出させ、これをろ過、水洗して該顔料中に含まれる遊離銅の含有量を２００ｐｐｍ以下とし、次いで結晶転移処理を行って安定型結晶形を有する顔料に変換することを特徴とする安定型銅フタロシアニン顔料の製造方法が提供される。
【００１１】
【発明の実施の形態】
以下に本発明を更に詳細に説明する。
本発明の安定化銅フタロシアニン顔料は、遊離銅の含有量が２００ｐｐｍ以下、好ましくは１００ｐｐｍ以下であることが特徴である。
尚、本発明における遊離銅の含有量は、銅フタロシアニン顔料クルードを濃硫酸に完全に溶解した後、水や氷水に析出させてろ過、洗浄し、ろ液および洗浄水の混合液の硫酸水溶液中に含まれている銅の量を原子吸光分析法（原子発光分析法）で定量した値である。
【００１２】
銅フタロシアニンは前記したように、合成上遊離の銅を含有することは避けられない。特に、銅フタロシアニン粒子中に含有する遊離銅は数パーセント濃度の酸による浸漬、洗浄処理では除去することはできない。また、一般に遊離銅の分析方法である塩酸法では、顔料粒子内に含まれている遊離銅を全て抽出あるいは溶出させて定量することは難しい。また、銅フタロシアニンを如何に細かく磨砕しても含有されている遊離銅を除去することは困難である。顔料粒子を溶解させてはじめて結晶内に含まれている遊離銅が抽出あるいは溶出除去できることを本発明者らは見いだした。
【００１３】
例えば、合成上がり（合成直後）の銅フタロシアニンクルードを、５重量％の硫酸水溶液中に浸漬、攪拌、ろ過、洗浄（酸処理と称する）して得られた粗粒子中に含有する遊離銅を塩酸法（顔料１ｇに１０ｍｌのエタノールと１００ｍｌの塩酸を加え１０分間煮沸し、放冷後ろ過、塩酸で洗浄し、ろ液と洗浄液の混合物中の銅を原子吸光法で定量する。）で測定すると５８３ｐｐｍである。ところが、この粗粒子を濃硫酸に完全に溶解し、これを水あるいは氷水中に加えて銅フタロシアニンの結晶を析出させ、これをろ別、洗浄した後、ろ液および洗浄水の混合液中の銅の含有量を原子吸光分析法で測定すると６７００ｐｐｍであった。
【００１４】
また、銅フタロシアニンクルード粗粒子を磨砕した後、５重量％の硫酸水溶液等で酸処理し、溶剤で顔料化した銅フタロシアニンの遊離銅を塩酸法で測定すると２６８ｐｐｍであるが、顔料粒子を濃硫酸に溶解し、その後水中に銅フタロシアニンを析出させてろ別、洗浄した後、ろ液および洗浄水混合液中の銅の含有量を原子吸光分析法で測定すると１６６０ｐｐｍであった。
【００１５】
更に、合成上がりの銅フタロシアニンの粗粒子を濃硫酸に溶解及び析出させ、ろ過分離後、顔料化した銅フタロシアニン顔料は塩酸法で遊離銅を測定すると３．９ｐｐｍであるが、再度濃硫酸に溶解し、その後水あるいは氷水中に銅フタロシアニンを析出させてろ別、洗浄した後、ろ液および洗浄水中の銅の含有量を原子吸光分析法で測定すると５０ｐｐｍである。
以上のように、硫酸溶解工程を経ている顔料のみが濃硫酸に再度溶解させても遊離銅の存在は１００ｐｐｍ以下であることが判明した。
【００１６】
従って、銅フタロシアニン中に含有する遊離銅を２００ｐｐｍ、好ましくは１００ｐｐｍ以下にするのには、合成終了後溶剤を留去した銅フタロシアニン顔料クルードを、完全に硫酸等の酸に溶解し、酸で遊離銅を溶解除去する工程を経ることが不可欠である。顔料粒子を溶解させる方法として濃硫酸を用いる方法以外に、燐酸、ジエチル硫酸、クロル酢酸、クロルナフタレン、キノリン等を溶剤として用いる方法があるが、溶解度、安全性、廃液処理、経済性等から、一般には濃硫酸に溶解し、水等に析出させ再生する方法が好ましいが、この方法に限定されるものではない。
【００１７】
濃硫酸を使用する場合には、例えば、上記の銅フタロシアニン顔料クルードを、農硫酸、好ましくは該顔料クルードの６重量倍以上の量の濃硫酸に完全に溶解し、この溶液を、好ましくは該硫酸溶液量の１０重量倍以上の量の水、氷水に注いで銅フタロシアニン顔料の結晶を析出させ、あるいは氷上に結晶を析出させ、結晶をろ過、水洗した後、必要に応じて更にアルカリ性水溶液で洗浄し、該顔料クルード中の遊離銅の含有量を２００ｐｐｍ以下とし、次いで該顔料の微細化および結晶転移処理を行うことが好ましい。結晶転移処理は、従来公知の方法が使用され、特に限定されない。例えば、有機溶剤中での処理、もしくは無機塩類の存在下あるいは非存在下での磨砕処理等が挙げられる。
【００１８】
遊離銅の存在により悪影響を受ける可能性がある例としては、例えば、ポリオレフィン系樹脂では熱安定性を低下させ、紫外線硬化インク、電子線硬化塗料、インクジェットインキ、カラーフィルターカラー等ではこれらの保存安定性を悪くし、表示不良の原因となり、カラー電子写真用トナーではトナーの帯電性を低下させることが知られている。また、前記したようにプラスチックの高温発泡剤として使用されているアゾジカルボアミド系発泡剤は、銅の存在で発泡温度が低下し、発泡速度が促進されることが知られており、他の有彩色の顔料と併用した時、発泡速度の差により、銅フタロシアニンを用いたところが先に発泡し、均一な発泡体が得られないことがある。また、銅は人体に悪影響を与える可能性が有る。
【００１９】
従って、銅は、できるだけ環境に排出されないことが好ましい。しかし、遊離銅を含有する銅フタロシアニンを使用する限りにおいては、上記問題を解決することが難しいといえる。そこで、上記問題点を解決するためには、銅フタロシアニンを完全に溶解させて銅フタロシアニン骨格を形成する銅以外の遊離銅を２００ｐｐｍ、好ましくは１００ｐｐｍ以下にする工程を経て製造された安定型銅フタロシアニン顔料を用いることが不可欠である。
【００２０】
本発明の安型化銅フタロシアニン顔料は、各種用途の着色剤として使用される。用途としては、例えば、印刷インキ、インクジェット記録用インキ、塗料、顔料捺染剤、繊維・プラスチック用、電子写真複写機用のトナー等の画像記録用、カラーフィルター等の画像表示用等の顔料着色組成物等が挙げられる。該顔料は繊維・プラスチック用の着色剤として使用する場合には、これらに直接分散させて使用される。他の用途においては、該顔料は、通常バインダー樹脂あるいはビヒクル等の分散媒体に分散させて使用されるが、分散媒体は各用途において従来から使用されているものが使用でき、特に限定されない。上記用途の製造方法も特に限定されず、それぞれの公知の製造方法がいずれも使用できる。
【００２１】
【実施例】
以下に製造例、実施例、比較例および参考例を挙げて本発明を更に具体的に説明するが、本発明はこれら実施例に限定されるものではない。尚、以下の文中の部および％は、特に断りのない限り重量基準である。
尚、銅フタロシアニン顔料中の遊離の銅の含有量は、該顔料０．５ｇを１０ｍｌの９５％濃硫酸に完全に溶解し、この硫酸溶液を１００ｍｌの氷水に徐々に加えて該顔料の結晶を析出させ、該結晶をろ別、２００ｍｌの洗浄水で洗浄し、ろ液と洗浄水との混合液中の銅の含有量を原子吸光分析法（日立製作所製偏光ゼーマン原子吸光分光光度計Ｚ８０００型を使用）で測定した値である。以下では「硫酸法による遊離銅の測定値」と称する。
【００２２】
製造例１
無水フタル酸３０部、尿素４５部と触媒として無水フタル酸に対して０．２％のモリブデン酸アンモニウムを芳香族系高沸点溶媒９０部に加え、撹拌しながら徐々に昇温し、１５０℃で塩化第一銅５．３部を反応容器に加え、更に昇温し１７５℃とする。この温度で４時間反応させる。反応後、得られた生成物をろ過し、次いでメタノールで洗浄した後、希酸、希アルカリで処理し、ろ過、水洗、乾燥して安定型銅フタロシアニン顔料クルード２６．７部を得た。硫酸法による遊離銅の測定値は６７００ｐｐｍであった。
【００２３】
製造例２
製造例１で得た安定型銅フタロシアニン顔料クルード２５部を９５％濃硫酸２５０部に撹拌しながら徐々に添加し、溶解させる。その後、７０℃に昇温して１時間撹拌し、完全に溶解させる。その後、この硫酸溶液を５リットルの氷水に徐々に添加して銅フタロシアニンの結晶を析出させ、ろ過、水洗、乾燥して不安定型銅フタロシアニン２３．８部を得た。硫酸法による遊離銅の測定値は５０ｐｐｍであった。
【００２４】
比較例１
製造例１で得た安定型銅フタロシアニン顔料クルード１５部を、スチールボール５００部、釘５０部と共に３時間振動ミルにて磨砕した。
得られた内容物を取り出してソルベントフィニッシュにより顔料化を行ない、希酸処理、水洗、乾燥して１３部の安定型銅フタロシアニン顔料を得た。硫酸法による遊離銅の測定値は１６６０ｐｐｍであった。
【００２５】
実施例１
製造例２で得た不安定型銅フタロシアニン４００部を、食塩１６００部およびジエチレングリコール４００部と共にニーダー中で内容物の温度を８０〜１００℃に保って６時間磨砕を行った。得られた内容物を希酸処理、ろ過、水洗、乾燥し、微細な安定型銅フタロシアニン顔料を得た。硫酸法による遊離銅の測定値は５０ｐｐｍであった。
【００２６】
実施例２
製造例２で得た不安定型銅フタロシアニン１００部を、フタルイミドメチル銅フタロシアニン３部、スルホン化銅フタロシアニン１部、カルバゾールジオキサジンバイオレット３部、シードとしてのε型銅フタロシアニン顔料１０部、食塩３００部およびジエチレングリコール１１０部と共にニーダー中で内容物の温度を１００〜１１０℃に保って２０時間磨砕を行った。得られた内容物を希酸加熱処理し、ろ過、水洗、乾燥し、ε型銅フタロシアニン顔料を主成分として含む安定型銅フタロシアニン顔料組成物を得た。硫酸法による遊離銅の測定値は５０ｐｐｍであった。
【００２７】
実施例３
ポリプロピレンナチュラル樹脂３００ｇに実施例１で得た顔料１．２ｇを添加ブレンドし、２オンス成形機（成形設定温度２００℃）にて成形プレートを作製した。成形した成形プレートをギヤーオーブンに入れ、熱老化試験を行った。熱老化現象は、クラック発生を終点とした。試験温度は１５０℃、熱老化現象の観察は５０時間までは２時間毎、５０時間以上は２４時間毎に行った。結果は表１の通りである。
【００２８】
参考例１
顔料を添加しない以外は実施例３と同様にして成形プレートを作製し、熱老化試験を行った。結果は表１の通りである。
【００２９】
比較例２
実施例１で得た顔料に代えて比較例１で得た顔料１．２ｇを用いる以外は実施例３と同様にして成形プレートを作製し、熱老化試験を行った。結果は表１の通りである。遊離銅の多い比較例２の熱老化時間は極めて短くなっている。

【００３０】
実施例４
ジアリルフタレートポリマー（ダイソーダップＡ大阪曹達（株）製）７部をジペンタエリスリトールヘキサアクリレート（アロニクスＭ４０２東亜合成（株）製）５０部で溶解する。これに実施例１で得た顔料２０部、炭酸カルシウム５部、変性ビスフェノールＡジアクリレート（アロニクスＭ２１０東亜合成（株）製）１５部およびα−アミノアセトフェノン（ＩＧ９０７チバガイギー製）３部を入れプレミキシングし、更に三本ロールで３回練りし、オフセット印刷用インキを得た。このインキは６０℃で３週間の保存試験でゲル化することなく、流動性は良好であった。
【００３１】
比較例３
実施例１で得た顔料に代えて比較例１で得た顔料２０部を用いる以外は実施例４と同様にしてオフセット印刷用インキを得た。実施例４と同様に６０℃で２０時間保存した時点でゲル化し印刷インキとして使用は困難となった。
【００３２】
実施例５
ビスフェノール型ポリエステル樹脂粉末と実施例１で得た微細化青色顔料、微細化赤色顔料（Ｃ．Ｉ．ピグメントレッド１２２）、微細化黄色顔料（Ｃ．Ｉ．ピグメントイエロー１５５）およびカーボンブラック顔料（Ｃ．Ｉ．ピグメントブラック７）を、それぞれ高速混合機で予備混合後、加熱三本ロールにより十分混練りし、冷却後、粗砕し、微細に分散した顔料を３０％の濃度で含有する青色、赤色、黄色および黒色の粗砕粉を得た。次いで、上記の青色加工品１２．４部、赤色加工品１８．３部、黄色加工品１４．０部、黒色加工品１８．３部をそれぞれ採り、荷電制御剤２．８部およびビスフェノール型ポリエステル樹脂粉末を加えて１００部にして、常法に従って押出成型機にて混練りし、冷却、粗砕後、ジェットミルで微粉砕し、分級して平均粒径７〜８μｍの微粉末を得た。これらの微粉末に流動化剤を添加し、キャリアの磁性鉄粉と混合し、４色のフルカラー電子写真乾式現像剤とした。フルカラー複写機にて現像し、カブリの発生もなく鮮明な４色フルカラー画像が得られた。
【００３３】
実施例６
実施例１で得た青色顔料５部、スチレン−アクリレート−メタクリル酸ジエタノールアミン塩共重合体３部、エチレングリコール２２部、グリセリン８部および水６２部からなる水性顔料分散液を作り、分散しなかった顔料の粗粒子を超遠心分離機で除去し、インクジェット用水性シアンインキを得た。オンデマンド型のインクジェットプリンターで、上記シアンインキを用いて画像情報をプリントし、鮮明な青色画像を得た。
【００３４】
実施例７
実施例２の青色顔料１００部、ベンジルメタクリレート／メタクリル酸／２−ヒドロキシエチルメタクリレート（６０／２０／２０モル比）共重合体（重量平均分子量３０，０００）１００部、シクロヘキサン１４０部およびプロピレングリコールモノメチルエーテルアセテート１６０部をペイントコンディショナーでプレミキシングした後、顔料濃度が１５％になるようにプロピレングリコールモノメチルエーテルアセテートを加え、顔料分散剤としてＤｉｓｐｅｒｂｙｋ−１６３（ビックケミー社製）を顔料に対して２０％添加し、ダイノミル分散機（シンマルエンタープライズ社製）で分散させた。ここで得られた分散物は７０℃１週間で増粘することなくガラス基板に塗布し、透過率、コントラスト比、耐熱性および耐光性を評価した結果、いずれの物性にも優れた青色カラーフィルターが得られた。
【００３５】
実施例８
実施例１で得られた銅フタロシアニン０．５ｇと発泡剤ダイブローＡＣ２０４０Ｌ（大日精化工業製）０．５ｇを試験管に入れ更に流動パラフィンを添加する。これらを均一に混ぜた後、ガス量自動測定装置（ＣＥＬＬＴＥＣＨＮＯ社製）で昇温中ガス発生量を測定した。結果は表２の通りである。
【００３６】
参考例２
実施例１で得られた銅フタロシアニンに代えて製造例１で得た銅フタロシアニンを用いる以外は実施例８と同様にして試験を行った。結果は表２の通りである。
【００３７】
参考例３
銅フタロシアニンを入れずに、発泡剤ダイブローＡＣ２０４０Ｌ０．５ｇのみで発生ガス量を測定した。結果は表２の通りである。
遊離銅の少ない実施例７は発泡剤単独とガス発生温度およびガス量共に差がないが、遊離銅の多い参考例２はガス発生温度が約１０度低く、また発生ガス量も１０ｍｌほど少ない。
【００３８】

【００３９】
【発明の効果】
以上の本発明によれば、塗料やインキの保存安定性を損ない、オレフィン樹脂等の酸化劣化を促進し、プラスチック用高温発泡剤であるアゾジカルボアミド系発泡剤の発泡速度を速める等の悪影響を及ぼす遊離銅の含有量が著しく低減された安定型銅フタロシアニン顔料が提供される。本発明の安定型銅フタロシアニン顔料は、繊維・プラスチック用着色剤、顔料捺染剤、インキ、塗料、トナー等の画像記録用、カラーフィルター等の画像表示用等の顔料着色組成物用に好適である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is a stable type copper phthalocyanine pigment in which the content of free copper crystallized from a purified unstable type copper phthalocyanine pigment to a stable type is significantly reduced, a production method thereof, and a pigment coloring composition using the same. Related to colored articles. More specifically, the present invention relates to a stable copper phthalocyanine pigment having a total free copper content of 200 ppm or less in a pigment, a method for producing the same, and a pigmented composition and a colored article using the same.
[0002]
[Prior art]
Conventionally, stable copper phthalocyanine pigments are clear and fast greenish blue pigments, such as cyan ink for various printing inks, cyan toner for full-color electrophotographic copiers and full-color printers, cyan ink for inkjet printers, and writing instruments. It has been awarded as a pigment for use in blue and sky blue colors, or as a blue colorant for paints and plastics.
[0003]
This stable copper phthalocyanine pigment is a complex pigment having a porphyrin ring as a ligand and copper as a central metal. In the Wyler method, which is a typical method for producing copper phthalocyanine, copper salts such as phthalic anhydride, urea and cuprous chloride are used irrespective of the normal pressure method and the pressure method. In the phthalodinitrile method, phthalodinitrile is used. Nitriles and copper salts are used. As the condensation catalyst, ammonium molybdate, phosphomolybdic acid, or the like is used.
[0004]
A copper phthalocyanine pigment (hereinafter sometimes simply referred to as a pigment) used for a coloring agent or the like is usually prepared by synthesizing a pigment crude by the above-mentioned production method, and then performing a pigmentation treatment by salt milling, solvent salt milling, or an acid slurry method. (Pigmentation). All of these pigmentation treatments are for the purpose of making the pigment crude into fine particles and converting the crystal form into stable copper phthalocyanine, and unreacted copper salts that are not incorporated into the pigment as the central metal of the complex. (Sometimes referred to as "free copper" in the present invention) can only be removed to some extent, and it is inevitable that free copper remains in the pigment particles.
[0005]
Thus, since the pigment obtained by these methods contains free copper in the particles, when processing the pigment into a colorant, when dispersed in various dispersion media, depending on the dispersion conditions Unreacted copper is freely precipitated from the ground (crushed) pigment particles. Free copper precipitated in such a form is dispersed in a dispersion medium together with copper phthalocyanine used as a colorant, for example, to promote oxidation of a polyolefin resin or the like as a dispersion medium, or to adversely affect heat resistance. is there. Further, when copper phthalocyanine is used as a pigment for a negatively charged electrophotographic toner, the amount of charge is reduced in a high-humidity environment, and problems such as a change in image density and fogging may occur. This problem is related to the content of free copper in the pigment, and the use of the pigment in which the content of free copper in the pigment is 2000 ppm or less has been proposed (Patent Document 1). In addition, since copper belongs to heavy metals, it may have an unfavorable effect in an era where environmentally friendly materials are prioritized. Therefore, from the demands of the times, a stable copper phthalocyanine pigment in which the content of free copper contained in the pigment is extremely small has been demanded.
[0006]
Patent Document 1 discloses a method for reducing the content of free copper in the pigment by distilling off the solvent from the reaction product after synthesis under reduced pressure, and removing the residue (crude pigment) from an acid such as water or diluted sulfuric acid. Or a method of sufficiently washing with water or an acid in a pigmentation step of making the crude pigment finer. However, in these methods, the free copper content when the above residue is washed with water (the pigment is dissolved in sulfuric acid, the solution is added to water to precipitate the pigment crystals, and the crystals are separated, washed, and filtered. Patent Literature 1 describes that 12,000 ppm can be reduced to 2000 ppm in a mixed solution of water and a washing liquid (determined by an atomic absorption method of copper). Patent Document 1 does not disclose a method for reducing the free copper content in that case.
[0007]
[Patent Document 1]
JP-A No. 11-7161
[Problems to be solved by the invention]
Free copper tends to impair the storage stability of paints and inks and accelerate the deterioration of heat resistance of polyolefin resins and the like, and a stable copper phthalocyanine containing less free copper is desired. In addition, since free copper tends to increase the foaming rate of an azodicarbonamide-based foaming agent used as a high-temperature foaming agent for plastics, a blue plastic foam using a copper phthalocyanine pigment and another pigment were used. There is a difference in the foaming speed between another chromatic plastic foam and a problem such as an uneven foaming state. In addition, it is preferable that the content of copper, which is a heavy metal, be as close to zero as possible from the viewpoint of environmental problems.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stable copper phthalocyanine pigment having a significantly reduced free copper content and a method for producing the same.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result of dissolving the copper phthalocyanine pigment completely in concentrated sulfuric acid, passing through a step of precipitating in water or the like, by filtering and washing, contained in the pigment particles. It has been found that free copper can be significantly reduced, and the present invention has been completed based on this finding.
[0010]
According to the present invention, there is provided a stable copper phthalocyanine pigment characterized in that the content of free copper contained in the pigment is 200 ppm or less.
Further, according to the present invention, the copper phthalocyanine pigment crude is completely dissolved in concentrated sulfuric acid, and the sulfuric acid solution is added to water or ice water or on ice to precipitate copper phthalocyanine crystals, which are filtered and washed with water. Providing a method for producing a stable copper phthalocyanine pigment, wherein the content of free copper contained in the pigment is reduced to 200 ppm or less, and then a crystal transition treatment is performed to convert the pigment into a pigment having a stable crystal form. Is done.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail.
The stabilized copper phthalocyanine pigment of the present invention is characterized in that the content of free copper is 200 ppm or less, preferably 100 ppm or less.
Incidentally, the content of free copper in the present invention, after completely dissolving the copper phthalocyanine pigment crude in concentrated sulfuric acid, precipitated in water or ice water, filtered and washed, in a sulfuric acid aqueous solution of a mixture of filtrate and washing water Is a value determined by the atomic absorption spectrometry (atomic emission spectrometry) of the amount of copper contained in.
[0012]
As described above, it is inevitable that copper phthalocyanine contains synthetically free copper. In particular, free copper contained in copper phthalocyanine particles cannot be removed by immersion and washing treatment with an acid having a concentration of several percent. In addition, in the hydrochloric acid method, which is a method for analyzing free copper, it is generally difficult to extract or elute and quantify all free copper contained in pigment particles. Also, it is difficult to remove the contained free copper, no matter how finely the copper phthalocyanine is ground. The present inventors have found that free copper contained in the crystal can be extracted or eluted and removed only after the pigment particles are dissolved.
[0013]
For example, copper phthalocyanine crude that has been synthesized (immediately after synthesis) is immersed in a 5% by weight aqueous sulfuric acid solution, stirred, filtered, and washed (referred to as acid treatment). It is measured by the method (10 ml of ethanol and 100 ml of hydrochloric acid are added to 1 g of the pigment, and the mixture is boiled for 10 minutes, allowed to cool, filtered, washed with hydrochloric acid, and the amount of copper in the mixture of the filtrate and the washing solution is determined by the atomic absorption method). 583 ppm. However, the coarse particles were completely dissolved in concentrated sulfuric acid, and this was added to water or ice water to precipitate crystals of copper phthalocyanine.These crystals were separated by filtration, washed, and then mixed with the filtrate and the washing water. The copper content was 6700 ppm as measured by atomic absorption spectrometry.
[0014]
After grinding the coarse particles of copper phthalocyanine crude, acid treatment with a 5% by weight aqueous sulfuric acid solution or the like is performed, and the free copper of copper phthalocyanine pigmented with a solvent is measured by a hydrochloric acid method. After dissolving in sulfuric acid, copper phthalocyanine was precipitated in water, separated by filtration and washed, and then the content of copper in the filtrate and the mixture of washing water was measured by atomic absorption spectrometry to be 1660 ppm.
[0015]
Further, coarse copper phthalocyanine particles obtained after synthesis are dissolved and precipitated in concentrated sulfuric acid, and after filtration and separation, the pigmented copper phthalocyanine pigment is 3.9 ppm as measured by free hydrochloric acid by a hydrochloric acid method. After that, copper phthalocyanine is precipitated in water or ice water, separated by filtration and washed, and then the content of copper in the filtrate and the wash water is 50 ppm as measured by atomic absorption spectrometry.
As described above, it was found that the presence of free copper was 100 ppm or less even when only the pigment that had undergone the sulfuric acid dissolving step was redissolved in concentrated sulfuric acid.
[0016]
Therefore, in order to reduce the free copper contained in copper phthalocyanine to 200 ppm, preferably 100 ppm or less, the copper phthalocyanine pigment crude from which the solvent has been distilled off after completion of the synthesis is completely dissolved in an acid such as sulfuric acid and the like, and is liberated with an acid. It is essential to go through the step of dissolving and removing copper. Other than the method using concentrated sulfuric acid as a method for dissolving the pigment particles, there is a method using phosphoric acid, diethyl sulfuric acid, chloroacetic acid, chlornaphthalene, quinoline, etc. as a solvent, but from the viewpoint of solubility, safety, waste liquid treatment, economic efficiency, and the like, Generally, a method of dissolving in concentrated sulfuric acid and precipitating in water or the like for regeneration is preferable, but the method is not limited to this method.
[0017]
When concentrated sulfuric acid is used, for example, the above-mentioned copper phthalocyanine pigment crude is completely dissolved in agricultural sulfuric acid, preferably in an amount of 6% by weight or more of concentrated pigment sulfuric acid, and this solution is preferably dissolved in the sulfuric acid. Water of at least 10 times the weight of the sulfuric acid solution, poured into ice water to precipitate the crystals of the copper phthalocyanine pigment, or to precipitate the crystals on ice, filter the crystals, wash with water, and then, if necessary, further use an alkaline aqueous solution. It is preferable to wash the pigment crude to reduce the content of free copper in the pigment crude to 200 ppm or less, and then to carry out a treatment for refining and crystallizing the pigment. For the crystal transition treatment, a conventionally known method is used and is not particularly limited. For example, a treatment in an organic solvent, a grinding treatment in the presence or absence of an inorganic salt, and the like can be given.
[0018]
Examples of the possibility of being adversely affected by the presence of free copper include, for example, reducing thermal stability in polyolefin resins, and storage stability in ultraviolet curable inks, electron beam curable paints, inkjet inks, color filter colors, etc. It is known that the toner has a poor chargeability, causes display defects, and reduces the chargeability of the color electrophotographic toner. In addition, as described above, azodicarbonamide-based blowing agents used as high-temperature blowing agents for plastics are known to reduce the foaming temperature in the presence of copper and accelerate the foaming speed. When used in combination with a chromatic pigment, the place where copper phthalocyanine is used foams first due to the difference in foaming speed, and a uniform foam may not be obtained. In addition, copper may have an adverse effect on the human body.
[0019]
Therefore, it is preferable that copper is not discharged to the environment as much as possible. However, as long as copper phthalocyanine containing free copper is used, it can be said that it is difficult to solve the above problem. Therefore, in order to solve the above problems, stable copper phthalocyanine produced through a step of completely dissolving copper phthalocyanine to reduce free copper other than copper to form a copper phthalocyanine skeleton to 200 ppm, preferably 100 ppm or less. It is essential to use pigments.
[0020]
The stabilized copper phthalocyanine pigment of the present invention is used as a coloring agent for various uses. Uses include, for example, pigment coloring compositions for printing inks, ink jet recording inks, paints, pigment printing agents, image recording of fibers and plastics, toners for electrophotographic copying machines, and image display such as color filters. Objects and the like. When the pigment is used as a colorant for fibers and plastics, it is used by directly dispersing it in these. In other applications, the pigment is usually used by dispersing it in a dispersion medium such as a binder resin or a vehicle. However, the dispersion medium may be any of those conventionally used in each application, and is not particularly limited. The production method for the above application is not particularly limited, and any known production method can be used.
[0021]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, Comparative Examples, and Reference Examples, but the present invention is not limited to these Examples. In the following description, parts and percentages are by weight unless otherwise specified.
The content of free copper in the copper phthalocyanine pigment was determined by completely dissolving 0.5 g of the pigment in 10 ml of 95% concentrated sulfuric acid, and gradually adding the sulfuric acid solution to 100 ml of ice water to form crystals of the pigment. The crystals are separated by filtration, washed with 200 ml of washing water, and the content of copper in the mixture of the filtrate and the washing water is determined by atomic absorption spectroscopy (Zeeman type polarized light Zeeman atomic absorption spectrophotometer manufactured by Hitachi, Ltd.) Is used). Hereinafter, it is referred to as “measured value of free copper by the sulfuric acid method”.
[0022]
Production Example 1
30 parts of phthalic anhydride, 45 parts of urea and 0.2% ammonium molybdate with respect to phthalic anhydride as a catalyst were added to 90 parts of an aromatic high boiling point solvent, and the temperature was gradually increased while stirring, and 150 ° C. 5.3 parts of cuprous chloride are added to the reaction vessel, and the temperature is further raised to 175 ° C. The reaction is carried out at this temperature for 4 hours. After the reaction, the obtained product was filtered, then washed with methanol, treated with a dilute acid and a dilute alkali, filtered, washed with water and dried to obtain 26.7 parts of stable copper phthalocyanine pigment crude. The measured value of free copper by the sulfuric acid method was 6,700 ppm.
[0023]
Production Example 2
25 parts of the stable copper phthalocyanine pigment crude obtained in Production Example 1 is gradually added to 250 parts of 95% concentrated sulfuric acid with stirring to dissolve. Thereafter, the temperature is raised to 70 ° C., and the mixture is stirred for 1 hour to be completely dissolved. Thereafter, the sulfuric acid solution was gradually added to 5 liters of ice water to precipitate copper phthalocyanine crystals, which were filtered, washed with water and dried to obtain 23.8 parts of unstable copper phthalocyanine. The measured value of free copper by the sulfuric acid method was 50 ppm.
[0024]
Comparative Example 1
15 parts of the stable copper phthalocyanine pigment crude obtained in Production Example 1 was ground with a vibration mill for 3 hours together with 500 parts of steel balls and 50 parts of nails.
The obtained contents were taken out, pigmented by solvent finish, treated with a dilute acid, washed with water and dried to obtain 13 parts of a stable copper phthalocyanine pigment. The measured value of free copper by the sulfuric acid method was 1660 ppm.
[0025]
Example 1
400 parts of the unstable copper phthalocyanine obtained in Production Example 2 was ground together with 1600 parts of sodium chloride and 400 parts of diethylene glycol in a kneader while maintaining the temperature of the content at 80 to 100 ° C. for 6 hours. The obtained content was treated with a dilute acid, filtered, washed with water, and dried to obtain a fine stable copper phthalocyanine pigment. The measured value of free copper by the sulfuric acid method was 50 ppm.
[0026]
Example 2
100 parts of the unstable copper phthalocyanine obtained in Production Example 2, 3 parts of phthalimidomethyl copper phthalocyanine, 1 part of sulfonated copper phthalocyanine, 3 parts of carbazole dioxazine violet, 10 parts of ε-type copper phthalocyanine pigment as a seed, 300 parts of salt and Grinding was carried out for 20 hours in a kneader together with 110 parts of diethylene glycol while maintaining the temperature of the contents at 100 to 110 ° C. The obtained content was heated with diluted acid, filtered, washed with water, and dried to obtain a stable copper phthalocyanine pigment composition containing an ε-type copper phthalocyanine pigment as a main component. The measured value of free copper by the sulfuric acid method was 50 ppm.
[0027]
Example 3
1.2 g of the pigment obtained in Example 1 was added to and blended with 300 g of polypropylene natural resin, and a molded plate was produced using a 2 oz molding machine (molding setting temperature: 200 ° C.). The molded plate was placed in a gear oven and subjected to a heat aging test. The heat aging phenomenon ended at the occurrence of cracks. The test temperature was 150 ° C., and the observation of the heat aging phenomenon was performed every 2 hours until 50 hours, and every 24 hours after 50 hours. Table 1 shows the results.
[0028]
Reference Example 1
A molded plate was prepared in the same manner as in Example 3 except that no pigment was added, and a heat aging test was performed. Table 1 shows the results.
[0029]
Comparative Example 2
A molded plate was prepared in the same manner as in Example 3 except that 1.2 g of the pigment obtained in Comparative Example 1 was used instead of the pigment obtained in Example 1, and a heat aging test was performed. Table 1 shows the results. The heat aging time of Comparative Example 2 containing a large amount of free copper is extremely short.

[0030]
Example 4
7 parts of diallyl phthalate polymer (Daiso Dap A manufactured by Osaka Soda Co., Ltd.) is dissolved in 50 parts of dipentaerythritol hexaacrylate (Aronix M402 manufactured by Toagosei Co., Ltd.). 20 parts of the pigment obtained in Example 1, 5 parts of calcium carbonate, 15 parts of modified bisphenol A diacrylate (manufactured by Alonix M210, manufactured by Toa Gosei Co., Ltd.) and 3 parts of α-aminoacetophenone (manufactured by IG907 Ciba Geigy) were added thereto, followed by premixing. The mixture was further kneaded three times with three rolls to obtain an offset printing ink. The ink did not gel in a storage test at 60 ° C. for 3 weeks and had good fluidity.
[0031]
Comparative Example 3
An ink for offset printing was obtained in the same manner as in Example 4, except that 20 parts of the pigment obtained in Comparative Example 1 was used instead of the pigment obtained in Example 1. As in Example 4, it gelled when stored at 60 ° C. for 20 hours and became difficult to use as a printing ink.
[0032]
Example 5
Bisphenol-type polyester resin powder and the refined blue pigment obtained in Example 1, the refined red pigment (CI Pigment Red 122), the refined yellow pigment (CI Pigment Yellow 155), and the carbon black pigment (C Pigment Black 7) is preliminarily mixed in a high-speed mixer, kneaded well with a heated three-roll mill, cooled, crushed, and contains a blue color containing a finely dispersed pigment at a concentration of 30%. Red, yellow and black crushed powders were obtained. Then, 12.4 parts of the above-mentioned blue processed product, 18.3 parts of the red processed product, 14.0 parts of the yellow processed product, and 18.3 parts of the black processed product are respectively taken, and 2.8 parts of a charge control agent and bisphenol-type polyester are taken. The resin powder was added to make up to 100 parts, kneaded with an extruder according to a conventional method, cooled, crushed, finely crushed with a jet mill, and classified to obtain fine powder having an average particle size of 7 to 8 μm. . A fluidizing agent was added to these fine powders and mixed with the magnetic iron powder of the carrier to obtain four full-color electrophotographic dry developers. The image was developed with a full-color copying machine, and a clear four-color full-color image without fog was obtained.
[0033]
Example 6
An aqueous pigment dispersion comprising 5 parts of the blue pigment obtained in Example 1, 3 parts of styrene-acrylate-methacrylic acid diethanolamine salt copolymer, 22 parts of ethylene glycol, 8 parts of glycerin and 62 parts of water was prepared and not dispersed. The pigment coarse particles were removed by an ultracentrifuge to obtain an aqueous cyan ink for inkjet. Using an on-demand type inkjet printer, image information was printed using the above-described cyan ink, and a clear blue image was obtained.
[0034]
Example 7
100 parts of blue pigment of Example 2, 100 parts of benzyl methacrylate / methacrylic acid / 2-hydroxyethyl methacrylate (60/20/20 molar ratio) copolymer (weight average molecular weight 30,000), 140 parts of cyclohexane and propylene glycol monomethyl After premixing 160 parts of ether acetate with a paint conditioner, propylene glycol monomethyl ether acetate is added so that the pigment concentration becomes 15%, and Disperbyk-163 (manufactured by BYK Chemie) as a pigment dispersant is added to the pigment by 20%. Then, the mixture was dispersed with a Dynomill disperser (manufactured by Shinmaru Enterprise Co., Ltd.). The dispersion obtained here was applied to a glass substrate without thickening at 70 ° C. for 1 week, and evaluated for transmittance, contrast ratio, heat resistance and light resistance. As a result, a blue color filter having excellent physical properties was obtained. was gotten.
[0035]
Example 8
0.5 g of the copper phthalocyanine obtained in Example 1 and 0.5 g of the blowing agent Dieblo AC2040L (manufactured by Dainichi Seika Kogyo) are placed in a test tube, and liquid paraffin is further added. After these were uniformly mixed, the amount of gas generated during heating was measured by an automatic gas amount measuring device (manufactured by CELLTECHNO). Table 2 shows the results.
[0036]
Reference Example 2
A test was performed in the same manner as in Example 8, except that the copper phthalocyanine obtained in Production Example 1 was used instead of the copper phthalocyanine obtained in Example 1. Table 2 shows the results.
[0037]
Reference Example 3
The amount of generated gas was measured only with 0.5 g of blowing agent Dieblo AC2040L without adding copper phthalocyanine. Table 2 shows the results.
In Example 7 with a small amount of free copper, there is no difference in the gas generation temperature and gas amount from the foaming agent alone, but in Reference Example 2 with a large amount of free copper, the gas generation temperature is about 10 degrees lower and the amount of generated gas is as small as about 10 ml.
[0038]

[0039]
【The invention's effect】
According to the present invention, adverse effects such as impairing the storage stability of paints and inks, promoting oxidative deterioration of olefin resins and the like, and increasing the foaming rate of azodicarbonamide-based foaming agents, which are high-temperature foaming agents for plastics. And a stable copper phthalocyanine pigment having a significantly reduced free copper content. The stable copper phthalocyanine pigment of the present invention is suitable for pigment coloring compositions such as colorants for fibers and plastics, pigment printing agents, inks, paints, image recordings such as toners, image displays such as color filters, and the like. .

Claims

A stable copper phthalocyanine pigment, wherein the content of free copper contained in the pigment is 200 ppm or less.

The stable copper phthalocyanine pigment according to claim 1, which is a phthalocyanine pigment obtained by subjecting unstable copper phthalocyanine purified to the free copper content to a stable crystal form.

The copper phthalocyanine pigment crude is completely dissolved in concentrated sulfuric acid, and this sulfuric acid solution is added to water or ice water or on ice to precipitate crystals of copper phthalocyanine, which is filtered, washed with water and contained in the pigment. A method for producing a stable copper phthalocyanine pigment, which comprises converting the content of free copper to 200 ppm or less and then performing a crystal transition treatment to convert it to a pigment having a stable crystal form.

4. The method for producing a stable copper phthalocyanine pigment according to claim 3, wherein the crystal transition treatment is a treatment in an organic solvent or a grinding treatment in the presence or absence of inorganic salts.

A pigment coloring composition comprising the stable copper phthalocyanine pigment according to claim 1 and a dispersion medium.

The pigment coloring composition according to claim 5, which is a pigment coloring composition for ink, paint, pigment printing agent, fiber, plastic, image recording, or image display.

A method for coloring an article, comprising using the pigment coloring composition according to claim 5.

A colored article obtained by the method according to claim 7.