JP4517538B2 - Printing ink, printing method and printing package - Google Patents

Description

式中、Ｚは多価アルコールの残基であり、Ｒは炭素数２乃至４のアルキレン基であり、Ｒ_１は水素原子またはメチル基であり、ｎは１以上の数であり、ｍは２以上、特に３以上の数であり、ｐはゼロを含む１以下の数である。
上記式（１）の（メタ）アクリレートが誘導される多価アルコールとしては、トリメチロールプロパン、ジトリメチロールプロパン、ペンタエリスリトール、ジペンタエリスリトール、グリセリン、ジグリセリン、トリメチロールエタン、ジトリメチロールエタン、エリスリトール、キシリトール、マンニトール、ソルビトールなどが挙げられるが、勿論これに限定されない。
多価アルコールの変性に用いるアルキレンオキサイドとしては、エチレンオキサイドが好適であるが、プロピレンオキサイドなどの他のアルキレンオキサイドも勿論使用可能である。
【００３２】
熱重合開始剤としては有機過酸化物あるいはアゾ化合物等を用いることができる。
有機過酸化物としては、例えばジクミルパーオキサイド、ジ−ｔ−ブチルパーオキサイド、２，５−ジメチル−２，５−ビス（ｔ−ブチルパーオキシ）ヘキサン、２，５−ジメチル−２，５−ビス（ｔ−ブチルパーオキシ）ヘキシン−３、１，３−ビス（ｔ−ブチルパーオキシイソプロピル）ベンゼン、１，１−ビス（ｔ−ブチルパーオキシ）バラレート、ベンゾイル−パーオキサイド、ｔ−ブチルパーオキシベンゾエート、アセチルパーオキサイド、イソブチルパーオキサイド、オクタノイルパーオキサイド、デカノイルパーオキサイド、ラウロイルパーオキサイド、３，３，５−トリメチルヘキサノイルパーオキサイドおよび２，４−ジクロロベンゾイルパーオキサイド、ｍ−トルイルパーオキサイド等が挙げられる。
アゾ化合物としては、例えばアゾイソブチロニトリル、ジメチルアゾイソブチロニトリル等が挙げられる。
【００３３】
紫外線硬化性のものとしては紫外線ラジカル重合型、紫外線カチオン重合型いずれの形態でも良い。
紫外線ラジカル重合型のものとしては、アクリル系モノマー乃至プレポリマーと光ラジカル重合触媒との組み合わせが使用される。アクリル系モノマー乃至プレポリマーとしては、分子内に複数の（メタ）アクリロイル基を有するモノマー乃至プレポリマー或いはそれらの混合物が使用される。
光ラジカル重合触媒の代表的なものとしては、ベンゾイン及びそのアルキルエーテル類、アセトフェノン類、アントラキノン類、チオキサントン類、ケタール類、ベンゾフェノン類、キサントン類等がある。
紫外線カチオン重合型のものとして、例えば、紫外線硬化型エポキシ樹脂と光カチオン重合触媒の組み合わせが使用される。
紫外線硬化型エポキシ樹脂としては、分子内に脂環族基を有し且つ脂環基の隣接炭素原子がオキシラン環を形成しているエポキシ樹脂成分を含有するものであり、例えば分子内に少なくとも１個のエポキシシクロアルカン基、例えばエポキシシクロヘキサン環、エポキシシクロペンタン環等を有するエポキシ化合物等が単独或いは組み合わせで使用される。
その適当な例は、これに限定されないが、ビニルシクロヘキセンジエポキシド、ビニルシクロヘキセンモノエポキシド、３，４−エポキシシクロヘキシルメチル−３，４−エポキシシクロヘキサン・カーボキシレート、２−（３，４−エポキシシクロヘキシル−５，５−スピロ−３，４−エポキシ）シクロヘキサン−ｍ−ジオキサン、ビス（３，４−エポキシシクロヘキシル）アジペート、リモネンジオキサイド等である。
上記エポキシ樹脂と組み合わせで用いるカチオン性紫外線重合開始剤とは、紫外線によって分解し、ルイス酸を放出し、このルイス酸がエポキシ基を重合する作用を有するものであり、その例として、芳香族ヨードニウム塩、芳香族スルフォニウム塩、芳香族セレニウム塩、芳香族ジアゾニウム塩等が挙げられる。
【００３４】
本発明の印刷インキ層には、１次粒子の平均粒径０．０１乃至１μｍの透明微粒子を含有させることが、光輝性顔料の凝集を抑制し、その分散性を向上させて、インキの転移性を向上させ、更にその面配向性を高めて光輝性をも向上させる点で好ましい。光輝性顔料の配向を高める効果は、前述した着色顔料を配合することによっても得られるが、所定の平均粒径の透明微粒子を配合することによって、印刷インキ層の色調を変えることなく、光輝性顔料の配向性を高めることができる。
【００３５】
透明微粒子は樹脂からなるものでも、或いは非晶質シリカのような無機の透明微粒子であってもよい。
前者の場合、この微粒子は乳化重合法或いは無乳化剤乳化重合法で製造された粒径０．０１乃至１μｍの球状粒子であってよく、後述する単量体成分を水性媒体中で粒子径が０．０１乃至１μｍの範囲となるように乳化重合させることにより製造される。
モノマーとしては、一般に親油性で、ラジカル重合性のモノマーが挙げられ、例えばビニル芳香族モノマー、アクリル系モノマー、ビニルエーテル系モノマー等が挙げられる。
ビニル芳香族モノマーとしては、例えばスチレン、α−クロロスチレン、ｏ、ｍ，ｐ−クロロスチレン、ｐ−エチレンスチレン、ジビニルベンゼンなどが挙げられる。
アクリル系モノマーとしては、例えばメチルアクリレート、エチルアクリレート、ブチルアクリレート、２−エチルヘキシルアクリレート、シクロヘキシルアクリレート、メチルメタクリレート、エチルメタクリレート、ブチルメタクリレート、ヘキシルメタクリレート、２−ヒドロキシエチルアクリレート、３−ヒドロキシプロピルアクリレート、４−ヒドロキシブチルアクリレート、２−ヒドロキシエチルメタクリレート、エチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレート等が挙げられる。
ビニルエーテル系モノマーとしては、例えばビニル−ｎ−ブチルエーテル、ビニルフェニルエーテル、ビニルシクロヘキシルエーテル等が挙げられる。
ジオレフィン系モノマーとしては、例えばブタジエン、イソプレン、クロロプレン等が挙げられる。
モノオレフィン系モノマーとしては、例えばエチレン、プロピレン、イソブチレン−１、ブテン−１、ペンテン−１、４−メチルペンテン−１などが挙げられる。
上記モノマーは、非極性のモノマーであるが、微粒子の分散性の調節のため、所望によりカチオン性モノマーや、アニオン性モノマーと共重合させて用いることができ、或いは溶解防止のため、架橋性モノマーと共重合させて用いることができる。
カチオン性モノマーとしては、塩基性窒素原子のようなカチオン性基を含有するモノマー、例えば、ジメチルアミノアクリレート、ジメチルアミノエチルアクリレート、ジエチルアミノプロピルアクリレート、Ｎ−アミノエチルアミノプロピルアクリレート、ジメチルアミノメタクリレート、ジメチルアミノエチルメタクリレート、ジエチルアミノプロピルメタクリレート、Ｎ−アミノエチルアミノプロピルメタクリレート、ビニルピリジン、２−ビニルイミダゾール、２−ヒドロキシ−３−アクリルオキシプロピルメチルアンモニウムクロライド、アクリニトリル等の１級、２級または３級アミノ基或いは第４級アンモニウム基を含有するモノマーが使用される。
アニオン性モノマーとしては、スルホン酸、カルボン酸、ホスホン酸或いはそれの塩のようなアニオン性を有するモノマー、好適にはスルホン酸またはその塩の基を有するモノマー、例えばスチレンスルホン酸、ビニルスルホン酸、アクリルスルホン酸、アクリルアミドメチルプロパンスルホン酸、アクリルスルホン酸、メタクリルスルホン酸、アクリル−２−エチルスルホン酸、メタクリル−２−エチルスルホン酸等、さらにこれらのナトリウム、カリウム、カルシウム等の塩類があげられる。
架橋性モノマーとしては、ジビニルベンゼン（ＤＶＢ）、ジアリルフタレート（ＤＡＰ）、トリアリルイソシアヌレートなどを挙げることができる。
【００３６】
また、無機の透明微粒子としては、非晶質シリカ、特に乾式法（四塩化ケイ素の熱分解）による非晶質シリカや、湿式法による非晶質シリカの内、前述した粒径を満足するものが使用される。
【００３７】
本発明の印刷インキにおいて、光輝性顔料は５乃至４０重量％、特に７乃至３５重量％の濃度で含有させることが望ましい。即ち、光輝性顔料の濃度が５重量％を下回ると、本発明の範囲内にある場合に比して、光輝感が不足する傾向があり（比較例３）、一方光輝性顔料の濃度が４０重量％を上回ると、本発明の範囲内にある場合に比して、インキの転移性が著しく悪くなり、光輝性の高い良好な印刷物を得ることが困難になる（比較例４）。
透明微粒子は０．５乃至２０重量％、特に１乃至１０重量％の濃度で含有させるのが望ましい。即ち、透明微粒子の濃度が０．５重量％を下回ると、透明微粒子を加えていない場合に比して、光輝性顔料粒子の分散性、ばらけ易さやインキの転移性に対して格別な効果が発現しない（比較例８）。一方、透明微粒子の濃度が２０重量％を上回ると、本発明の範囲内にある場合に比して、光輝性顔料粒子の分散性、ばらけ易さやインキの転移性の向上はなく、却って光輝感が低下する傾向がある（比較例９）。
また、この印刷インキは３５℃において剪断速度１００ｓｅｃ^−１における見掛け粘度η_１００が２Ｐａ・ｓｅｃ以下、特に０．０５乃至１Ｐａ・ｓｅｃの範囲にあるのが好ましい。即ち、η_１００が２Ｐａ・ｓｅｃを上回ると、η_１００が本発明の範囲内にある場合に比して、インキが刷版上に溜まる傾向があり、全体的に厚盛りの再現性の悪い印刷物となる（比較例５）。
【００３８】
［被印刷体］
本発明の印刷インキは、各種被印刷体、特に金属缶、プラスチック缶、金属キャップ、プラスチックキャップ、ガラスボトル、プラスチックボトル、プラスチックカップ、プラスチックチューブ容器、各種パウチ、ボトル用インモールドラベル等への印刷に適用できる。
本発明は、ツーピース缶やスリーピース缶などのそれ自体公知の任意の金属缶体に有利に適用することができる。
これらの金属缶体の内、金属或いは被覆金属の絞り・深絞り成形、絞り・しごき成形、絞り・曲げ伸ばし成形・しごき成形で形成されたツーピース缶（シームレス缶）では、成形後の缶体に外面印刷を行うのが通例であり、このような缶体への外面印刷により、光輝性を付与するのに本発明は有用である。
そこで、本発明をこのツーピース缶について説明するが、本発明は勿論この例に限定されない。
【００３９】
本発明において印刷に用いるツーピース缶は、金属素材或いは有機被覆金属素材の絞り−再絞り加工、絞り−しごき加工或いは絞り−曲げ伸ばし加工−しごき加工等により製造される。有機被覆金属板をカップに成形したものでも、金属製カップに後から有機被覆を設けたものでもよいが、製造の容易さ及び簡略さの点で、有機被覆金属板をカップに成形したものが好適である。
【００４０】
このツーピース缶の断面構造の一例を示す図２において、このカップ１０は金属基体１１とその内面側表面上に設けられた内面有機被膜１２と基体の他方の表面に設けられた外面有機被膜１３とから成っている。
断面構造の他の例を示す図３において、カップに成形された金属基体１１に対して、後から塗装により施された内面有機被膜１２ａを備えており、金属基体１１の外面には格別の有機被膜は形成されていないが、この外面には、前に指摘し、以下に詳述するホワイトコートなどの塗装と印刷が施されることになる。
【００４１】
本発明では、金属板としては各種表面処理鋼板やアルミニウム等の軽金属板が使用される。
表面処理鋼板としては、冷圧延鋼板を焼鈍後二次冷間圧延し、亜鉛メッキ、錫メッキ、ニッケルメッキ、電解クロム酸処理、クロム酸処理等の表面処理の一種または二種以上行ったものを用いることができる。好適な表面処理鋼板の一例は、電解クロム酸処理鋼板であり、特に１０乃至２００ｍｇ／ｍ^２の金属クロム層と１乃至５０ｍｇ／ｍ^２（金属クロム換算）のクロム酸化物層とを備えたものであり、このものは塗膜密着性と耐腐食性との組合せに優れている。
表面処理鋼板の他の例は、０．５乃至１１．２ｇ／ｍ^２の錫メッキ量を有する硬質ブリキ板である。このブリキ板は、金属クロム換算で、クロム量が１乃至３０ｍｇ／ｍ^２となるようなクロム酸処理或いはクロム酸／リン酸処理が行われていることが望ましい。更に他の例としてはアルミニウムメッキ、アルミニウム圧接等を施したアルミニウム被覆鋼板が用いられる。
【００４２】
軽金属板としては、所謂純アルミニウム板の他にアルミニウム合金板が使用される。耐腐食性と加工性との点で優れたアルミニウム合金板は、Ｍｎ ０．２乃至１．５重量％、Ｍｇ ０．８乃至５重量％、Ｚｎ ０．２５乃至０．３重量％、及びＣｕ ０．１５乃至０．２５重量％、残部がＡｌの組成を有するものである。これらの軽金属板も、金属クロム換算で、クロム量が２０乃至３００ｍｇ／ｍ^２となるようなクロム酸処理或いはクロム酸／リン酸処理が行われていることが望ましい。
【００４３】
金属板の素板厚、即ち缶底部の厚み(tB)は、金属の種類、容器の用途或いはサイズによっても相違するが、一般に０．１０乃至０．５ｍｍの厚みを有するのがよく、この内でも表面処理鋼板の場合には、０．１０乃至０．３ｍｍの厚み、また軽金属板の場合には０．１５乃至０．４０ｍｍの厚みを有するのがよい。
【００４４】
金属基体上に所望により設ける有機被覆は、熱可塑性樹脂でも、熱硬化性樹脂でも或いはその組成物であってもよいが、一般には熱可塑性樹脂であるのが好適である。尚、金属基体がアルミニウム系基体である場合には、図３に示すとおり、外面の樹脂被覆は省略しても差し支えない。
【００４５】
上記金属板上に被覆される熱可塑性樹脂としては、結晶性の熱可塑性樹脂が好ましく、その例として、ポリエチレン、ポリプロピレン、エチレン−プロピレン共重合体、エチレン−酢酸ビニル共重合体、エチレン−アクリルエステル共重合体、アイオノマー等のオレフィン系樹脂フィルム；ポリエチレンテレフタレート、ポリブチレンテレフタレート、エチレンテレフタレート／イソフタレート共重合体等のポリエステル；ナイロン６、ナイロン６，６、ナイロン１１、ナイロン１２等のポリアミド；ポリ塩化ビニル；ポリ塩化ビニリデン等を挙げることができる。
【００４６】
上記熱可塑性樹脂の被覆層には、金属板を隠蔽し、また絞り−再絞り成形時等に金属板へのしわ押え力の伝達を助ける目的で無機フィラー（顔料）を含有させることができる。また、このフィルムにはそれ自体公知のフィルム用配合剤、例えば非晶質シリカ等のアンチブロッキング剤、各種帯電防止剤、滑剤、酸化防止剤、紫外線吸収剤等を公知の処方に従って配合することができる。
【００４７】
無機フィラーとしては、ルチル型またはアナターゼ型の二酸化チタン、亜鉛華、グロスホワイト等の無機白色顔料；バライト、沈降性硫酸バライト、炭酸カルシウム、石膏、沈降性シリカ、エアロジル、タルク、焼成或は未焼成クレイ、炭酸バリウム、アルミナホワイト、合成乃至天然のマイカ、合成ケイ酸カルシウム、炭酸マグネシウム等の白色体質顔料；カーボンブラック、マグネタイト等の黒色顔料；ベンガラ等の赤色顔料；シエナ等の黄色顔料；群青、コバルト青等の青色顔料を挙げることができる。これらの無機フィラーは、樹脂当り１０乃至５００重量％、特に１０乃至３００重量％の量で配合させることができる。
【００４８】
被覆熱可塑性樹脂の金属板への被覆は、熱融着法、ドライラミネーション、押出コート法等により行われ、被覆樹脂と金属板との間に接着性（熱融着性）が乏しい場合には、例えばウレタン系接着剤、エポキシ系接着剤、酸変性オレフィン樹脂系接着剤、コポリアミド系接着剤、コポリエステル系接着剤等を介在させることができる。
【００４９】
また、熱可塑性樹脂の厚みは、一般に３乃至５０μｍ、特に５乃至４０μｍの範囲にあることが望ましい。フィルムを用いた熱融着の場合、未延伸のものでも延伸のものでもよい。
【００５０】
特に好適なフィルムとして、エチレンテレフタレート単位またはブチレンテレフタレート単位を主体とするポリエステルを、Ｔ−ダイ法やインフレーション製膜法でフィルムに成形し、このフィルムを延伸温度で、逐次或いは同時二軸延伸し、延伸後のフィルムを熱固定することにより製造されたフィルムを挙げることができる。
【００５１】
原料ポリエステルとしては、ポリエチレンテレフタレートそのものも使用可能であるが、フィルムの到達し得る最高結晶化度を下げることが耐衝撃性や加工性の点で望ましく、この目的のためにポリエステル中にエチレンテレフタレート以外の共重合エステル単位を導入するのがよい。エチレンテレフタレート単位或いはブチレンテレフタレート単位を主体とし、他のエステル単位の少量を含む融点が２１０乃至２５２℃共重合ポリエステルの二軸延伸フィルムを用いることが特に好ましい。尚、ホモポリエチレンテレフタレートの融点は一般に２５５乃至２６５℃である。
【００５２】
一般に共重合ポリエステル中の二塩基酸成分の７０モル％以上、特に７５モル％以上がテレフタル酸成分から成り、ジオール成分の７０モル％以上、特に７５モル％以上がエチレングリコールまたはブチレングリコールから成り、二塩基酸成分の１乃至３０モル％、特に５乃至２５モル％がテレフタル酸以外の二塩基酸成分から成ることが好ましい。
【００５３】
テレフタル酸以外の二塩基酸としては、イソフタル酸、フタル酸、ナフタレンジカルボン酸等の芳香族ジカルボン酸：シクロヘキサンジカルボン酸等の脂環族ジカルボン酸：コハク酸、アジピン酸、セバチン酸、ドデカンジオン酸等の脂肪族ジカルボン酸：の１種又は２種以上の組合せが挙げられ、エチレングリコールまたはブチレングリコール以外のジオール成分としては、プロピレングリコール、ジエチレングリコール、１，６−ヘキシレングリコール、シクロヘキサンジメタノール、ビスフェノールＡのエチレンオキサイド付加物等の１種又は２種以上が挙げられる。勿論、これらのコモノマーの組合せは、共重合ポリエステルの融点を前記範囲とするものが望ましい。
【００５４】
用いるポリエステルやコポリエステルは、フィルムを形成するに足る分子量を有するべきであり、このためには固有粘度(I.V.)が０．５５乃至１．９ｄｌ／ｇ、特に０．６５乃至１．４ｄｌ／ｇの範囲にあるものが望ましい。
【００５５】
フィルムの延伸は一般に８０乃至１１０℃の温度で、面積延伸倍率が２．５乃至１６．０、特に４．０乃至１４．０となる範囲で行うのがよく、フィルムの熱固定は、１３０乃至２４０℃、特に１５０乃至２３０℃の範囲で行うのがよい。
【００５６】
積層に際しては、過度の結晶化を防ぐ目的で、積層されるフィルムが結晶化温度域を通過する時間を可及的に短くし、好ましくはこの温度域を１０秒以内、特に５秒以内で通過するようにする。このために、積層に際して金属素材のみを加熱し、フィルム積層後直ちに積層体を強制冷却するようにする。冷却には、冷風、冷水との直接的な接触や強制冷却された冷却ローラの圧接が用いられる。この積層に際してフィルムを融点近傍の温度に加熱し、積層後急冷を行えば、結晶配向度を緩和させることも可能なことが理解されるべきである。
【００５７】
接着用プライマーを用いる場合に、フィルムへの接着用プライマーとの密着性を高めるために、フィルムの表面をコロナ放電処理しておくことが一般に望ましい。コロナ放電処理の程度は、そのぬれ張力が４４dyne/cm 以上となるようなものであることが望ましい。
【００５８】
この他、フィルムへのプラズマ処理、火炎処理等のそれ自体公知の接着性向上表面処理やウレタン樹脂系、変性ポリエステル樹脂系等の接着性向上コーティング処理を行っておくことも可能である。
【００５９】
ポリエステルフィルムと金属素材の間に所望により設ける接着プライマーは、金属素材とフィルムとの両方に優れた接着性を示すものである。密着性と耐腐食性とに優れたプライマー塗料の代表的なものは、種々のフェノール類とホルムアルデヒドから誘導されるレゾール型フェノールアルデヒド樹脂と、ビスフェノール型エポキシ樹脂とから成るフェノールエポキシ系塗料であり、特にフェノール樹脂とエポキシ樹脂とを５０：５０乃至５：９５重量比、特に４０：６０乃至１０：９０の重量比で含有する塗料である。
【００６０】
接着プライマー層は、一般に０．３乃至５μｍの厚みに設けるのがよい。接着プライマー層は予め金属素材上に設けてもよく或いは予めポリエステルフィルム上に設けてもよい。
【００６１】
金属の被覆となるポリエステル層は、二軸延伸フィルムの形で施す代わりに、所謂押出コートで設けることもできる。この押出コート法では、加熱された金属基体の上にダイスから押し出された溶融樹脂のウエッブを供給し、ラミネートロールで圧着した後、直ちに急冷を行うようにする。
【００６２】
被覆に用いる熱硬化性樹脂塗料としては、例えば、フェノール−ホルムアルデヒド樹脂、フラン−ホルムアルデヒド樹脂、キシレン−ホルムアルデヒド樹脂、ケトン−ホルムアルデヒド樹脂、尿素ホルムアルデヒド樹脂、メラミン−ホルムアルデヒド樹脂、アルキド樹脂、不飽和ポリエステル樹脂、エポキシ樹脂、ビスマレイミド樹脂、トリアリルシアヌレート樹脂、熱硬化性アクリル樹脂、シリコーン樹脂、油性樹脂、或は上記熱硬化性樹脂と熱可塑性樹脂塗料、例えば、塩化ビニル−酢酸ビニル共重合体、塩化ビニル−マレイン酸共重合体、塩化ビニル−マレイン酸−酢酸ビニル共重合体、アクリル重合体、飽和ポリエステル樹脂との組成物等を挙げることができる。これらの樹脂塗料は単独でも２種以上の組合せでも使用される。
上記熱硬化性樹脂塗料の内でも、エポキシ樹脂（ａ）とこのエポキシ樹脂に対する硬化剤樹脂（ｂ）との組み合わせが好ましい。
これらの硬化剤樹脂の内でも、フェノールホルムアルデヒド樹脂、特に多環多価フェノールを含有するフェノール−アルデヒド樹脂成分を用いることが、フィルムに対する密着性、腐食成分に対するバリヤー性及び耐加工性の点で望ましい。
【００６３】
ツーピース缶（シームレス缶）への成形は、それ自体公知の手段、例えば絞り−再絞り加工、絞り−再絞り−しごき加工、絞り−曲げ伸ばし再絞り加工、絞り−曲げ伸ばし−しごき加工等で行われる。
【００６４】
例えば、深絞り成形（絞り−再絞り成形）によれば、被覆金属板から成形された前絞りカップを、このカップ内に挿入された環状の保持部材とその下に位置する再絞りダイスとで保持する。これらの保持部材及び再絞りダイスと同軸に、且つ保持部材内を出入し得るように再絞りポンチを配置する。再絞りポンチと再絞りダイスとを互いに噛みあうように相対的に移動させる。
これにより、前絞りカップの側壁部は、環状保持部材の外周面から、その曲率コーナー部を経て、径内方に垂直に曲げられて環状保持部材の環状底面と再絞りダイスの上面とで規定される部分を通り、再絞りダイスの作用コーナー部により軸方向にほぼ垂直に曲げられ、前絞りカップよりも小径の深絞りカップに成形することができる。
【００６５】
更に、再絞りダイスの作用コーナー部の曲率半径（Ｒd）を、金属板素板厚（ｔB）の１乃至２．９倍、特に１．５乃至２．９倍の寸法とすることにより、側壁部の曲げ伸ばしによる薄肉化を有効に行うことができる。のみならず、側壁部の下部と上部とにおける厚みの変動が解消され、全体にわたって均一な薄肉化が可能となる。一般に、缶胴の側壁部は素板厚（ｔB ）に対する薄肉化率（厚みの変動率）を５乃至４５％（−５乃至−４５％）、特に５乃至４０％（−５乃至−４０％）の厚みに薄肉化することができる。
【００６６】
深絞り缶の場合、下記式（１）
【式１】

式中、Ｄは剪断したラミネート材の径であり、
ｄはポンチ径である、
で定義される絞り比ＲD は一段では１．１乃至３．０の範囲、トータルでは１．５乃至５．０の範囲にあるのがよい。
【００６７】
また再絞り或いは曲げ伸ばし再絞りの後方にしごきダイスを配置して、側壁部に対して、下記式（２）
【式２】

式中、ｔＢは素板厚であり、ｔW は側壁部の厚みである
で定義されるしごき率ＲI が５乃至７０％、特に１０乃至６０％の厚みになるようにしごきで薄肉化することもできる。
【００６８】
絞り成形等に際して、被覆金属板或は更にカップに、各種滑剤、例えば流動パラフィン、合成パラフィン、食用油、水添食用油、パーム油、各種天然ワックス、ポリエチレンワックスを塗布して成形を行うのがよい。滑剤の塗布量は、その種類によっても相違するが、一般に０．１乃至１０ｍｇ／ｄｍ^２、特に０．２乃至５ｍｇ／ｄｍ^２の範囲内にあるのがよく、滑剤の塗布は、これを溶融状態で表面にスプレー塗布することにより行われる。
【００６９】
カップへの絞り成形性を向上させるため、樹脂被覆絞りカップの温度を被覆樹脂のガラス転移点（Ｔｇ）以上、特に熱結晶化温度以下の範囲に予め設定して、樹脂被覆層の塑性流動を容易にした状態で成形することが有利である。
【００７０】
成形後の内面側有機被覆金属製カップは、カップ開口部の耳の部分を切断する、所謂トリミングを行った後、印刷工程に付する。このトリミング処理に先立って、成形後のカップを被覆樹脂のガラス転移点（Ｔｇ）以上で融点よりも低い温度に加熱して、被覆樹脂の歪みを緩和しておくことができる。この操作は、熱可塑性樹脂の場合特に被覆と金属との密着性を高めるために有効である。
【００７１】
［印刷］
本発明では、光輝性顔料として平均粒径が５乃至２５μｍのアルミフレーク顔料を５乃至４０重量％の量で含有すると共に、３５℃において剪断速度１００ｓｅｃ ^−１ における見掛け粘度η _１００ が２Ｐａ・ｓｅｃ以下である印刷インキを用い、ＪＩＳＡ硬度で９０度以下の硬度を有する樹脂凸版を使用して、刷版上の印刷インキをブランケットに転写し、ブランケット上の印刷インキを被印刷体に転写させることにより、被印刷体への印刷を行う。この印刷に際して、印刷インキ層の平均膜厚が０．２乃至１０μｍとなり、印刷インキ層中に光輝性顔料粒子（アルミフレーク顔料）の占める面積率（Ｓ）が１０％以上、特に２０％以上であるように印刷を行うが望ましい。
【００７２】
印刷インキ層の膜厚は、刷版へのインキの転移量を調節するなどの公知の手段で容易に調節することができる。
また、光輝性顔料粒子の占める面積率（Ｓ）を高めるには、刷版への転移がむらなく一様に行われるようにすると共に、光輝性顔料粒子が面方向に配向するようにする（面方向の面積が大きくなる）。
【００７３】
刷版へのインキの転移を有効に行うために、インキパンからのインキの汲み上げに、表面に溝が刻印された彫刻ローラ（斜線型彫刻ローラ）または表面に格子状の微小孔が刻印された彫刻ローラ（格子型彫刻ローラ）を用いることが有効である。これらの彫刻ローラを用いることにより、版胴と汲み上げローラとが圧接しても、光輝性顔料粒子が破砕されることがなく、また、汲み上げローラから版胴へのインキの転移が円滑に進行し、更に光輝性顔料粒子が面方向に配向する傾向が大きくなるという極めて好都合な作用が達成される。
【００７４】
斜線型彫刻ローラの場合、ローラ軸線に対して、２５乃至９０度未満、特に４５乃至８５度の一定間隔の平行線状に溝が形成されている。溝の深さは、印刷インキの粘度によっても相違するが、一般に１０乃至６０μｍ、特に１０乃至４０μｍの範囲にあるのが望ましい。また、溝のピッチは一般に８０乃至３００本／インチ、特に１２０乃至２７５本／インチの範囲にあるのが望ましく、溝の幅は線数によっても異なるが、８０乃至２００μｍの範囲にあるのが望ましい。
一方、格子型彫刻ローラの場合、２方向の互いに交差する一定間隔の平行線群より形成される格子状部分に断面が台形状を成す微小孔（セル）が多数設けられている。孔の深さは、印刷インキの粘度によっても相違するが、一般に１０乃至４０μｍ、特に１０乃至３０μｍの範囲にあるのが望ましい。また、格子のピッチは一般に８０乃至３００本／インチ、特に１２０乃至２５０本／インチの範囲にあるのが望ましい。２方向の交差する平行線群のローラ軸線に対して成す角度は、一方向が２５乃至７５度、特に３０乃至６０度の範囲にあり、他の一方向は３３５乃至２８５度、特に３３０乃至３００度の範囲にあるのがよく、２方向の平行線群、ローラ軸線に対して対象となるのが良い。彫刻ローラの材質は、特に制限されないが、一般にスチールで形成されている。
格子型彫刻ローラにおけるセル容積は、一般に６乃至１８ｃｃ／ｍ^２の範囲にあるものが望ましい。
適当な彫刻ローラは、アニロックスローラの商品名で入手しうる。
【００７５】
本発明に用いる印刷機の概略構造を示す図４において、光輝性顔料含有インキはインキパン２１内に収容されており、このインキと接するように、彫刻汲み上げローラ２３が駆動回転可能に設けられている。彫刻汲み上げローラ２３の周囲にはインキ層の厚みを制御するためのドクターブレード２４が配置されており、更に、彫刻汲み上げローラ２３と接するように、版胴２５が設けられている。更に、版胴２５と接するように、版胴２５からのインキ層を受領し缶体外表面に転写するためのブランケット胴２６も設けられている。
パン２１内の光輝性顔料含有インキは、彫刻汲み上げローラ２３の表面に保持されて汲み上げられ、ドクターブレード２４との接触により厚みを調節され、版胴２５と接触して、版胴２５の画線部に塗布される。版胴上のインキ層は次いでブランケット胴２６の表面に転写され、ブランケット２６上のインキ層は、ブランケット胴に接触する缶体（図示せず）に転移して、印刷像の形成が行われる。
版胴２５の刷版としては、樹脂凸版が用いられる。樹脂凸版の硬度は特に重要であり、ＪＩＳＡ硬度計により求めた硬度が９０度以下の樹脂凸版が好適に用いられる。刷版の硬度が９０度より大きいと、粒径の大きな光輝性顔料が刷版上に堆積し、転移不良となる（比較例１０）。このような低硬度の刷版の好適な例として、フレキソ印刷用の樹脂版が挙げられる。
【００７６】
図４に示す印刷機では、彫刻汲み上げローラ２３により汲み上げられるインキ層は版胴２５の刷版に供給されているが、彫刻汲み上げローラ２３と版胴２５との間にゴムローラを介在させ、汲み上げられたインキ層がゴムローラを介して刷版に供給されるようにしてもよい。
【００７７】
また、図４に示す印刷機では、インキパン２１より彫刻汲み上げローラ２３によりインキを汲み上げるが、インキパン２１の代わりにフレキソ印刷において公知のインキチャンバー２７を使用しても勿論良い。特に、高速印刷時にはインキチャンバー２７の方がインキの飛散が少なく好適である。図５にこの構成例を示す。
【００７８】
本発明による印刷方法では、上記印刷インキ層の上にクリヤー塗膜を設けることが好ましい。即ち、本発明では、被印刷体外面に印刷インキ層がオフセット方式などにより施されるため、印刷インキ層の外面をクリヤー塗膜で保護することが必須となるのである。
このクリヤー塗膜は、単に印刷インキ層を擦傷や剥離から機械的に保護するだけではなく、印刷インキ層外面からの乱反射などを防止して、光輝性を向上させるという補助的効果をも有している。
【００７９】
印刷インキ層の上に施すクリヤー塗膜としては、一般に製缶印刷の分野で仕上げワニスと呼ばれるものが使用される。このクリヤー塗膜としては、印刷インクに関して説明した樹脂のうち、透明性に優れたものが、光輝性顔料や着色剤の添加なしに使用され、この樹脂は加熱硬化性のものでも、紫外線硬化性のものでも、何れであってもよい。
【００８０】
クリヤー塗膜の厚みは、印刷インキ層の保護が十分なものである限り、特に制限はないが、一般に３乃至１０μｍ、特に４乃至６μｍの範囲にあることが好適である。
一方、クリヤー塗膜の形成は、図４に示した印刷機における版胴２５の代わりに、アプリケーターローラを使用し、このアプリケーターローラを印刷された缶体外表面と接触させることにより、同様に行われる。
【００８１】
印刷インキ層の形成と、クリヤー塗膜の形成とは、いわゆるウエット・オン・ウエットの関係で行うこともできるし、印刷インキ層の硬化を行った後、クリヤー塗膜の形成を、いわゆるウエット・オン・ドライの関係で行うこともできる。
【００８２】
印刷インキ層及びクリヤー塗膜の硬化は、加熱硬化の場合、１８０乃至２２０℃の温度を使用できる。一方、紫外線硬化の場合、紫外線としては、近紫外領域をも含めて、一般に波長２００乃至４３０ｎｍ、特に２４０乃至４２０ｎｍの光線が使用される。紫外光源としては、ハライドランプ、高圧水銀灯、低圧水銀灯等が使用される。コーティング層の厚みは小さいので、硬化に要するエネルギーはかなり少なくてすむことが利点であり、一般に５００乃至５０００ジュール／ｍ^２等のエネルギーで十分である。
【００８３】
［印刷包装体］
本発明の印刷包装体は、包装体外面に施された光輝性顔料（アルミフレーク顔料）を含有する印刷インキ層と、この印刷インキ層の上に設けられたクリヤー塗膜とを有している。印刷インキ層に存在する光輝性顔料（アルミフレーク顔料）は入射光に対して金属的反射光、即ち正面反射光を与え、印刷インキ層に光輝性のある外観を与える。
【００８４】
本発明の印刷包装体では、上記印刷インキ層の上にクリヤー塗膜を備えていることが必須不可欠である。即ち、インキ層が裏印刷されたフィルムのラミネートとは異なり、本発明では、包装体外面に印刷インキ層がオフセット方式などにより施される。このため、印刷インキ層の外面をクリヤー塗膜で保護することが必須となるのである。
このクリヤー塗膜は、単に印刷インキ層を擦傷や剥離から機械的に保護するだけではなく、印刷インキ層外面からの乱反射などを防止して、光輝性を向上させるという補助的効果をも有している。
【００８５】
本発明は、上記構成の印刷包装体において、下記の３つの要件、
Ａ．印刷インキ層の平均膜厚が０．２乃至１０μｍ、特に０．３乃至３μｍ、最も好適には０．５乃至２μｍであること、
Ｂ．印刷インキ層中に存在する光輝性顔料粒子の面積から算出される平均粒径（Ｄ）が３乃至２０μｍ、特に５乃至１６μｍであること、及び
Ｃ．光輝性顔料粒子の占める面積率（Ｓ）が１０％以上、特に２０％以上であること、
の組合せに特徴を有するものであり、これにより、明るく、重厚でしかもバランスのとれた光輝性を発現させることができる。
【００８６】
先ず、光輝性を有効に発現させるためには、印刷インキ層に小さく狭い範囲での一定の厚みの光輝性顔料粒子の存在範囲が必要である。
この印刷インキ層の平均膜厚が前述した範囲を下回ると、インキ層の転移むらが顕著となって、意図した光輝性が得られない傾向がある（比較例１１）。一方、この膜厚が上記範囲を上回ると、熱硬化性クリヤー塗膜の均一塗布が困難となったり、或いはインキ層の密着が不十分となって、外観が不良となり、やはり光輝性が不十分なものとなる（比較例１２）。
本発明では、印刷インキ層の厚みを、前述した比較的薄い範囲の厚みとすることにより、インキ層中における光輝性顔料粒子の配向を面配向乃至これに近い配向状態とし、明るい光輝性を印刷インキ層に付与することが可能となるものである。
【００８７】
また、印刷インキ層中に存在する光輝性顔料粒子の平均粒径（Ｄ）が上記の範囲にあることも、光輝性の点で重要である。本明細書において、通常の粉体についていわれるメジアン径（Ｄ50）とは異なり、印刷インキ層中の粒子の面積から実測される粒子の平均粒径（Ｄ）であり、具体的には、後述する実施例に述べる方法により測定されるものをいう。
この平均粒径（Ｄ）が上記範囲を下回ると、印刷インキ層が全体的に暗くなる傾向があり、光輝性が不十分なものとなる（比較例１）。一方、平均粒径（Ｄ）が上記範囲を上回ると、光輝性顔料のある部分とない部分との反射の差が大きすぎ、バランスのよい光輝性が得られない（比較例２）。
【００８８】
更に、本発明では、光輝性顔料粒子の占める面積率（Ｓ）が上記範囲内にあることが、光輝性に関してやはり重要である。この面積率（Ｓ）とは、印刷インキ層の面積に占める光輝性顔料粒子の占める面積の比率であり、具体的には、後述する実施例の方法で求めることができる。
この面積率（Ｓ）が上記範囲を下回ると、光輝性顔料による隠蔽が不十分となって、光輝性が不足する（比較例３）。
本発明において、光輝性顔料粒子の平均粒径（Ｄ）は、粒子１個を基準としてミクロにみた反射の強度（光輝性の光学的強度）に密接に関係するものであり、一方、面積率（Ｓ）は印刷インキ層を全体としてマクロにみた反射の分布と密接に関係するものであり、これらの各々が上記の範囲内にあることにより、明るく、重厚でしかもバランスのとれた光輝性が発現されるものである。
【００８９】
更に、これらの組合せに関しては、平均粒径（Ｄ）の自乗と面積率（Ｓ）との積（Ｄ^２×Ｓ）が３００以上、特に５００以上であることが、光輝性に関して望ましい。
この積が上記範囲を下回ると、上記範囲にあるものに比して、光輝性が低下する傾向が認められる（比較例１３）。
尚、上述した本発明における平均粒径（Ｄ）の自乗と面積率（Ｓ）との積（Ｄ^２×Ｓ）は、便宜上有効数字２桁の量とした。
【００９０】
【実施例】
以下の実施例に基づき本発明を更に詳細に説明する。
尚、以下の実施例中、実施例３は、本発明の範囲外の参考例である。
【００９１】
［インキ中の光輝性顔料の平均粒径］
光輝性顔料を分散させた印刷インキを適当な溶媒で希釈し、この希釈溶液を用いて、レーザ散乱法により平均粒径を体積基準で測定した（レーザ回折式粒度分布測定装置ＳＡＬＤ−３０００（島津製作所））。
［インキの見掛け粘度測定］
液体用レオメーターＡＲＥＳ−１００ＦＲＴ−ＢＡＴＨ−ＳＴＤ（レオメトリック・サイエンティフィック・エフ・イー（株））にコーン・プレートタイプの治具を取りつけて３５℃でインキの定常流粘度の測定を行い、剪断速度１００ｓｅｃ^-1での見掛け粘度η_１００を得た。
［インキの蒸発速度の測定］
予め重量を測定した厚さ０．３ｍｍ、長さ２０ｃｍ、幅５ｃｍの缶蓋用アルミ板の片面に厚さ１０μｍとなるようにインキを展色した。この展色板を速やかに秤量した後、２２℃に空調された部屋に１時間放置し、再度秤量した。放置中、風の影響を受けないよう、高さ３０ｃｍの段ボール製の覆いで展色板の周りを囲った。放置前後のインキ重量より開放雰囲気中に放置された場合のインキの減少率を求めた。減少率の計算は、放置前のインキの重量をＷ１、放置後のインキの重量をＷ２とした時、１００×（Ｗ１−Ｗ２）／Ｗ１により算出した。
【００９２】
［印刷］
図４に印刷機の概略を示す。インキパンに入れたインキを格子状の彫刻を施した彫刻ロールによりピックアップし、樹脂凸版に転移させた。この樹脂凸版上の画像を、ブランケットを介して被印刷体に印刷した。
彫刻ロールには、ロール軸線に対して４５度と１３５度の互いに直交する１２０線／インチのピッチの平行線群より形成される格子部分に、孔の開口部の正方形の一辺が１８０μｍ、孔の底となる正方形の一辺が１１０μｍとなる倒立角錐台形状の深さ３０μｍの孔が設けられたもの（セル容積１８ｃｃの彫刻ロール）、孔の開口部の正方形の一辺が１７０μｍ、孔の底となる正方形の一辺が１１０μｍとなる倒立角錐台形状の深さ２０μｍの孔が設けられたもの（セル容積１２ｃｃの彫刻ロール）、孔の開口部の正方形の一辺が１６０μｍ、孔の底となる正方形の一辺が１１０μｍとなる倒立角錐台形状の深さ１５μｍの孔が設けられたもの（セル容積８ｃｃの彫刻ロール）、前記平行線群のピッチが６５線／インチの格子部分に深さ１６０μｍの断面形状が倒立角錐台形状の孔が設けられたもの（セル容積６９ｃｃの彫刻ロール）、前記平行線群のピッチが８５線／インチの格子部分に深さ１２０μｍの断面形状が倒立角錐台形状の孔が設けられたもの（セル容積５８ｃｃの彫刻ロール）、前記平行線群のピッチが３００線／インチの格子部分に深さ１４μｍの断面形状が倒立角錐台形状の孔が設けられたもの（セル容積５ｃｃの彫刻ロール）、あるいは前記平行線群線のピッチが３００線／インチの格子部分に深さ８μｍの断面形状が倒立角錐台形状の孔が設けられたもの（セル容積３ｃｃの彫刻ロール）を使用した。
ブランケットには、クッション層を有する金属印刷用のエアブランケットを使用した。
刷版には、後述する方法にて測定した硬度が７０度のフレキソ印刷用の樹脂凸版（サイレルＥＸＬ：デュポン（株））、硬度が７８度のフレキソ印刷用の樹脂凸版（サイレルＮＯＷ：デュポン（株））、硬度が９０度の樹脂凸版（Ｂ８３Ｓ：東京応化工業（株））、及び硬度９７度の樹脂凸版（ＷＦ９５ＤＩＩ：東京応化工業（株））を使用した。
【００９３】
［インキ転移重量の測定］
印刷直後の未硬化状態の被印刷体の重量Ｗ３［ｍｇ］と印刷前の被印刷体の重量Ｗ４［ｍｇ］及び印刷画面面積Ａｃｍ^２を用いて、１００×（Ｗ３−Ｗ４）／Ａより印刷画面１００ｃｍ^２当たリのインキ転移重量を求めた。
［被覆面積率（Ｓ）の測定］
作製した包装体を切り開いて平板状とし、反射型の顕微鏡により光輝性コーティング部分の拡大写真を撮影した。この写真を画像処理し、光輝性顔料部分による被覆面積率を求めた。信頼性を高めるため、複数の写真について測定した平均値をＳとした。
【００９４】
［光輝性顔料の平均粒径（Ｄ）の測定］
上記被覆面積率の測定に用いた写真を利用し、視野中の光輝性顔料による被覆面積Ａを計測し、次いでその視野にある光輝性顔料の個数ｎを計測した。
このＡとｎを用い、下記計算式（３）
Ｄ ＝（Ａ／ｎ）^１／２ （３）
により、面積法による粒径を算出した。平均粒径の信頼性を高めるため、複数の写真について測定した平均値をＤとした。
面積法により求めたコーティング層中の光輝性顔料の平均粒径（Ｄ）は、コーティング層を上から見たときに見える光輝性顔料の面積に基づいて算出した平均粒径であり、従って、粒子の面配向が悪かったり、重なり合っていれば、本来は同じ大きさの光輝性顔料が含まれている場合でも、Ｄの値は極端に異なることになる。
即ち、配向がよく、顔料がバラけている場合に比べ、配向が悪く、顔料が凝集している場合は、Ｄは、コーティング層中で、夫々の光輝性顔料が光輝感に寄与する程度を密接に関係した量である。
［硬化後のインキ皮膜の平均膜厚の測定］
接触式の表面粗度計を用いて、硬化後の印刷缶乃至印刷板につき、画線部と非画線部の凹凸を測定し、その値より平均膜厚を算出した。
［刷版硬度の測定］
刷版を平坦な実験台上に置き、ＪＩＳＡ硬度測定用の治具を用いて硬度を測定した。このときの硬度計の読みをＪＩＳＡ硬度とした。
【００９５】
［薄肉化シームレス缶の製造］
素板厚０．１８ｍｍ、調質度ＤＲ−９のティンフリースチール板（表面処理被覆量として金属クロム量１２０ｍｇ／ｍ^２、クロム酸化物量１５ｍｇ／ｍ^２とした）の缶内面になる側に厚さ２０μｍの２軸延伸ポリエチレンテレフタレート／イソフタレート共重合体フィルムを、一方、缶外面になる側に酸化チタンを２０重量％含有する厚さ１５μｍの２軸延伸ポリエチレンテレフタレート／イソフタレート共重合体フィルムをフィルムの融点で両面同時に熱接着し、直ちに水冷することにより有機被覆金属板を得た。この有機被覆金属板にグラマーワックスを均一に塗布した後、直径１６０ｍｍの円板に打ち抜き、常法に従って、浅絞りカップを成形した。この絞り工程における絞り比は１．５９である。
次いで、曲げ伸ばしによる第１次、第２次再絞り加工を行い、薄肉化深絞リカップを得た。再絞り工程の成形条件及び再絞り成形された深絞りカップの諸特性を以下に示す。
第１次再絞り比 １．２３
第２次再絞り比 １．２４
再絞りダイス作用コーナー部曲率半径 ０．３０ｍｍ
再絞りダイス保持コーナー部曲率半径 １．０ｍｍ
カップ径 ６６ｍｍ
カップ高さ １３０ｍｍ
側壁厚み変化率 −４０％
この後、常法に従ってドーミング成形を行った後、前記深絞りカップを２１５℃で１分間熱処理し、フィルムの加工歪みを取り除くとともに、潤滑剤を揮発させた。次いで、開口端部の縁切りを行い、高さ１２３ｍｍの樹脂被覆薄肉化シームレス缶を得た。
【００９６】
［実施例１］
ステンレス製のカップに液状ポリエステル樹脂（ＮＳ２４００：旭電化工業（株））を２００重量部入れ、撹拌しながら１１５重量部のジエチレングリコールブチルエーテルアセテートを加えた。次いで、アミノ樹脂（サイメル２３５：三井サイテック（株））１００重量部と酸触媒（キャタリスト６００：三井サイテック（株））１．５重量部を撹拌しながら加えた後、平均粒径１３μｍのノンリーフィングタイプのアルミペースト９５重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は１３重量％、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は２４ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は２８％及び平均粒径（Ｄ）は８．０μｍであり、Ｄ^２×Ｓは１８００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【００９７】
［実施例２］
ステンレス製のカップに液状ポリエステル樹脂（ＮＳ２４００：旭電化工業（株））を２５０重量部入れ、撹拌しながら１５０重量部のジエチレングリコールブチルエーテルアセテートを加えた。次いで、アミノ樹脂（サイメル２３５：三井サイテック（株））１５０重量部と酸触媒（キャタリスト６００：三井サイテック（株））２．０重量部を撹拌しながら加えた後、平均粒径８μｍのリーフィングタイプのアルミペースト７０重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は７重量％、３５℃におけるη_１００は０．１９Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は３％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は２２ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は３９％及び平均粒径（Ｄ）は４．１μｍであり、Ｄ^２×Ｓは６６０であった。また、乾燥後のインキ皮膜の平均膜厚は，１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【００９８】
［実施例３］（参考例）
ステンレス製のカップに液状ポリエステル樹脂（ＮＳ２４００：旭電化工業（株））を２００重量部入れ、撹拌しながら１１５重量部のジエチレングリコールブチルエーテルアセテートを加えた。次いで、アミノ樹脂（サイメル２３５：三井サイテック（株））１００重量部と酸触媒（キャタリスト６００：三井サイテック（株））１．５重量部を撹拌しながら加えた後、平均粒径１６μｍの酸化チタン被覆雲母１１０重量部を撹拌しながら加え、雲母粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は２１重量％、３５℃におけるη_１００は０．２４Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は１％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は２５ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は４４％及び平均粒径（Ｄ）は９．１μｍであり、Ｄ^２×Ｓは３６００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【００９９】
［実施例４］
ステンレス製のカップに液状ポリエステル樹脂（ＮＳ２４００：旭電化工業（株））を１８９重量部入れ、撹拌しながら１０８重量部のジエチレングリコールブチルエーテルアセテートを加えた。次いで、アミノ樹脂（サイメル２３５：三井サイテック（株））９４重量部と酸触媒（キャタリスト６００：三井サイテック（株））２．５重量部を撹拌しながら加えた後、平均粒径０．０４μｍのシリカ粉末（ＡＥＲＯＳＩＬ ＯＸ５０：日本アエロジル（株））２６重量部を加え、ホモジナイザー（特殊機化工業（株））を用いて１０００ｒｐｍの攪拌速度で１０分間激しく撹拌、分散させた。次いで、この透明微粒子含有樹脂溶液を３本ロールミルで練り、シリカ粉末を十分に分散させた。３本ロールミル処理後の透明微粒子含有樹脂溶液３４０重量部に、平均粒径１３μｍのノンリーフィングタイプのアルミペースト８０重量部を撹拌しながら加え、アルミ粒子を十分に分散させることで光輝性インキを得た。光輝性インキ中のアルミ含有率は１３重量％、シリカ粉末含有率は５重量％であり、３５℃におけるη_１００は０．２５Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は３３ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は４３％及び平均粒径（Ｄ）は８．４μｍであり、Ｄ^２×Ｓは３０００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．６μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１００】
［実施例５］
実施例４のインキをセル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて薄肉化シームレス缶に印刷した。インキ転移重量は２３ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は３３％及び平均粒径（Ｄ）は８．５μｍであり、Ｄ^２×Ｓは２４００であった。缶上のインキ量は実施例１とほぼ同様であるが、透明微粒子を添加したことにより実施例１に比べて光輝性顔料による被覆面積率と光輝性顔料の配向性の向上が見られた。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０１】
［実施例６］
平均粒径０．３μｍのシリカ粉末（シーホスターＫＥ−Ｅ３０：（株）日本触媒））を用いる以外は、実施例４と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有量は５重量％、３５℃におけるη_１００は０．２３Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキ転移重量は２２ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３１％及び平均粒径（Ｄ）は８．４μｍであり、インキの転移性、光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）及び平均粒径（Ｄ）は実施例５とほぼ同様となった。この場合、Ｄ^２×Ｓは２２００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０２】
［実施例７］
シリカ粉末を１３０重量部とする以外は、実施例６と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有量は２０重量％、３５℃におけるη_１００は０．５３Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキ転移重量は２３ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３２％及び平均粒径（Ｄ）は８．４μｍであり、インキの転移性、光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）及び平均粒径（Ｄ）は実施例５とほぼ同様となった。この場合、Ｄ^２×Ｓは２３００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．１μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０３】
［実施例８］
シリカ粉末を２．５重量部とする以外は、実施例４と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有量は０．５重量％、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキ転移重量は２１ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３１％及び平均粒径（Ｄ）は８．３μｍであり、インキの転移性、光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）及び平均粒径（Ｄ）は実施例５とほぼ同様となった。この場合、Ｄ^２×Ｓは２１００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．１μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０４】
［実施例９］
平均粒径１μｍのシリカ粉末（シーホスターＫＥ−Ｅ９０：（株）日本触媒）を用いることと、３本ロールミルによる練りを行わなかったこと以外は実施例４と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有量は５重量％、３５℃におけるη１００は０．２２Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキ転移重量は２２ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３０％及び平均粒径（Ｄ）は８．３μｍであり、インキの転移性、光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）及び平均粒径（Ｄ）は実施例５とほぼ同様となった。この場合、Ｄ^２×Ｓは２１００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０５】
［実施例１０］
平均粒径０．０１μｍのシリカ粉末（Ｒ９７４：日本アエロジル（株））を２．５重量部用いる以外は、実施例４と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有量は０．５重量％、３５℃におけるη１００は０．２１Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキ転移重量は２１ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３１％及び平均粒径（Ｄ）は８．４μｍであり、インキの転移性、光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）及び平均粒径（Ｄ）は実施例５とほぼ同様となった。この場合、Ｄ^２×Ｓは２２００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．１μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０６】
［実施例１１］
平均粒径５μｍのリーフィングタイプのアルミペーストを４７重量部用いる以外は、実施例２と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は５重量％、３５℃におけるη_１００は０．１９Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は２％であった。
セル容積８ｃｃの彫刻ロールと硬度９０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキの転移重量は１３ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は３４％及び平均粒径（Ｄ）は３．０μｍであり、Ｄ^２×Ｓは３００であった。また、乾燥後のインキ皮膜の平均膜厚は、０．７μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０７】
［実施例１２］
平均粒径１５μｍのノンリーフィングタイプのアルミペーストを５５０重量部用いる以外は、実施例１と同様にしてインキを調整した。光輝性インキ中の光輝性顔料含有率は４０重量％、３５℃におけるη_１００は０．６３Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は１８％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキの転移重量は２６ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は５７％及び平均粒径（Ｄ）は９．６μｍであり、Ｄ^２×Ｓは５３００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０８】
［実施例１３］
平均粒径２５μｍのノンリーフィングタイプのアルミペーストを７０重量部用いる以外は、実施例１と同様にしてインキを調整した。光輝性インキ中の光輝性顔料含有率は１０重量％、３５℃におけるη_１００は０．１９Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は４％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝感も優れていた。インキの転移重量は１５ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性顔料による被覆面積率（Ｓ）は１０％及び平均粒径（Ｄ）は２０μｍであり、Ｄ^２×Ｓは４０００であった。また、乾燥後のインキ皮膜の平均膜厚は、０．８μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１０９】
［実施例１４］
平均粒径１５μｍのノンリーフィングタイプのアルミペースト７０重量部と平均粒径８μｍのノンリーフィングタイプのアルミペースト２５重量部を用いる以外は実施例１と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、３５℃におけるη_１００は０．２１Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は２４ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は３７％及び平均粒径（Ｄ）は５．９μｍであり、Ｄ^２×Ｓは１３００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１１０】
［実施例１５］
撹拌羽、温度計、冷却管を装着した４つ口フラスコに、固形ポリエステル樹脂（バイロン２２０：東洋紡績（株））１３０重量部、トルエン１３０重量部、及びジエチレングリコールブチルエーテルアセテート８０重量部を入れ、撹拌しながら１１０℃に加熱し、ポリエステル樹脂を溶解した。この溶液を４０℃以下に冷却した後、アミノ樹脂（サイメル２３５：三井サイテック（株））１００重量部と酸触媒（キャタリスト６００：三井サイテック（株））１．３重量部を撹拌しながら加え、樹脂溶液を得た。この樹脂溶液に更に、平均粒径１３μｍのノンリーフィングタイプのアルミペースト９５重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有量は１３重量％、３５℃におけるη_１００は０．０６３Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は３０％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを、印刷面側にホワイトコート層を設けた２００ｍｌ溶接缶用シートに印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は１４ｍｇ／１００ｃｍ^２であった。この印刷板を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は１８％及び平均粒径（Ｄ）は８．２μｍであり、Ｄ^２×Ｓは１２００であった。また、乾燥後のインキ皮膜の平均膜厚は０．５μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１１１】
［実施例１６］
平均粒径８μｍのリーフィングタイプのアルミペーストを用いる以外は、実施例１５と同様にして光輝性インキを調整した。光輝性インキ中の光輝性顔料含有量は１３重量％、３５℃におけるη_１００は０．０６８Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は３０％であった。
セル容積５ｃｃの彫刻ロールと硬度７０度の刷版を装着した調整したインキを、印刷面側にホワイトコート層を設けた２００ｍｌ溶接缶用シートに印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は５ｍｇ／１００ｃｍ^２であった。この印刷板を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は２７％及び平均粒径（Ｄ）は４．３μｍであり、Ｄ^２×Ｓは５００であった。また、乾燥後のインキ皮膜の平均膜厚は，０．２μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１１２】
［実施例１７］
撹拌羽、温度計、冷却管を装着した四つ口フラスコに、脂環式エポキシ樹脂（ＵＶＲ６１１０：ユニオンカーバイド日本（株））３００重量部、ポリエステル樹脂（バイロンＧＫ８１０：東洋紡績（株））５０重量部及びオキセタンアルコール（ＯＸＴ−１：東亞合成化学工業（株））５０重量部を入れ、撹拌しながら１１０℃に加熱し、ポリエステル樹脂を完全に溶解した。この溶液を４０℃に冷却した後、光開始剤（ＵＶＩ−６９９０：ユニオンカーバイド日本（株））２０重量部と平均粒径１３μｍのノンリーフィングタイプのアルミペースト９５重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は１３重量％、３５℃におけるη_１００は２．０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は５％であった。
セル容積１８ｃｃの彫刻ロールと硬度７８度の刷版を装着した印刷機を用いて、調整したインキを、印刷面側にホワイトコート層を設けた２００ｍｌ溶接缶用シートに印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は４０ｍｇ／１００ｃｍ^２であった。この印刷板にメタルハライドランプを用いて１０００Ｊ／ｍ^２の紫外線を照射し、インキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は５１％及び平均粒径（Ｄ）は８．０μｍであった。また、Ｄ^２×Ｓは３３００であった。また、硬化後のインキ皮膜の平均膜厚は、３．１μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１１３】
［実施例１８］
セル容積５８ｃｃの彫刻ロールと硬度７８度の刷版を装着した印刷機を用いて、実施例１７のインキを、印刷面側にホワイトコート層を設けた２００ｍｌ溶接缶用シートに印刷したところ、インキは良好な転移性を示し、また印刷物の光輝性も優れていた。インキ転移重量は１１０ｍｇ／１００ｃｍ^２であった。この印刷板にメタルハライドランプを用いて１０００Ｊ／ｍ^２の紫外線を照射し、インキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は７１％及び平均粒径（Ｄ）は７．０μｍであり、Ｄ^２×Ｓは３５００であった。また、硬化後のインキ皮膜の平均膜厚は、１０μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１１４】
［比較例１］
平均粒径４μｍのリーフィングタイプのアルミペーストを使用する以外、実施例２と同様にして、光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は７重量％、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は５％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、印刷物は暗く、求める光輝感が得られなかった。インキ転移重量は１５ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は５９％及び平均粒径（Ｄ）は１．９μｍであり、Ｄ^２×Ｓは２１０であった。また、乾燥後のインキ皮膜の平均膜厚は、０．８μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したが、光沢は向上したものの、光輝感は改善されなかった。
【０１１５】
［比較例２］
平均粒径３０μｍのノンリーフィングタイプのアルミペーストを使用する以外、実施例１と同様にして、光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は１３重量％、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、キラキラしてはいたが、光輝性顔料の粒子が大きすぎるため、顔料のある部分とない部分の差が大きすぎ、バランスの良い光輝感は得られなかった。インキ転移重量は２３ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は１５％及び平均粒径（Ｄ）は２２μｍであり、Ｄ^２×Ｓは７３００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したが、光沢は向上したものの、光輝感は改善されなかった。
【０１１６】
［比較例３］
アルミペーストの配合量を２５重量部とする以外は、実施例１と同様にして、光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は４重量％、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は２％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、光輝性顔料の粒子が少なすぎ、光輝感は得られなかった。インキ転移重量は２２ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は８％及び平均粒径（Ｄ）は８．９μｍであり、Ｄ^２×Ｓは６３０であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したが、光沢は向上したものの、光輝感は改善されなかった。
【０１１７】
［比較例４］
アルミペーストの配合量を６５０重量部とする以外は、実施例１と同様にして、光輝性インキを調整した。光輝性インキ中の光輝性顔料含有率は４３重量％、３５℃におけるη_１００は１．１Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は１９％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、光輝性顔料の粒子が多すぎるため、転移が著しく悪く、印刷実施は困難であった。
【０１１８】
［比較例５］
撹拌羽、温度計、冷却管を装着した４つ口フラスコに、固形ポリエステル樹脂（バイロン２２０：東洋紡績（株））２００重量部とジエチレングリコールブチルエーテルアセテート１１５重量部を入れ、撹拌しながら１１０℃に加熱し、ポリエステル樹脂を溶解した。この溶液を４０℃以下に冷却した後、アミノ樹脂（サイメル２３５：三井サイテック（株））１００重量部と酸触媒（キャタリスト６００：三井サイテック（株））２．５重量部を撹拌しながら加えた。次いで、平均粒径１３μｍのノンリーフィングタイプのアルミペースト１００重量部を撹拌しながら加え、アルミ粒子を十分に分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は１３重量％、３５℃におけるη_１００は２．４Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は５％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、印刷物は光輝性に優れていたが、３５℃におけるη_１００が本発明の範囲より大きいためインキが刷版上に溜まる傾向があり、全体的に厚盛りの再現性の著しく悪い印刷物となった。
【０１１９】
［比較例６］
撹拌羽、温度計、冷却管を装着した４つ口フラスコに、固形ポリエステル樹脂（バイロン２２０：東洋紡績（株））１３０重量部、トルエン１６０重量部、及びジエチレングリコールブチルエーテルアセテート５０重量部を入れ、撹拌しながら１１０℃に加熱し、ポリエステル樹脂を溶解した。この溶液を４０℃以下に冷却した後、アミノ樹脂（サイメル２３５：三井サイテック（株））１００重量部と酸触媒（キャタリスト６００：三井サイテック（株））１．３重量部を撹拌しながら加え、樹脂溶液を得た。この樹脂溶液に更に、平均粒径１３μｍのノンリーフィングタイプのアルミペースト９５重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有量は１３重量％、３５℃におけるη_１００は０．０５３Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は３５％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷したところ、印刷中に版上、ブランケット上のインキが乾く傾向があり、版、ブランケット上にインキが堆積して缶に転移するインキ量が極端に少なかった。
【０１２０】
［比較例７］
平均粒径４μｍのシリカ粉末（サイロスフェアＣ−１５０４：富士シリシア化学（株））を用いることと、３本ロールミルによる練りを行わなかったこと以外は、実施例４と同様にして、光輝性インキを調整した。得られた光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有率は５重量％であり、３５℃におけるη_１００は０．３６Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷した。シリカ粉末の平均粒径が４μｍと大きいためシリカ粉末がブランケットに取り残される傾向がある他、転移重量も２２ｍｇ／１００ｃｍ^２となり、透明微粒子添加の効果が認められなかった。また、硬化後の印刷缶はインキ皮膜がざらざらし、外観が劣っていたが、キラキラした光輝感は良好であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は２４％及び平均粒径（Ｄ）は８．３μｍであり、Ｄ^２×Ｓは１７００であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したが、光沢は向上したものの、ざらざらした印刷物の外観は変わらなかった。
【０１２１】
［比較例８］
シリカ粉末を２重量部とする以外は、実施例４と同様にして光輝性インキを調整した。得られた光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有率は０．４重量％であり、３５℃におけるη_１００は０．２０Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は６％であった。
セル容積１２ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷した。インキの転移重量は２４ｍｇ／ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は２９％、平均粒径（Ｄ）は８．１μｍであり、Ｄ^２×Ｓは１９００であった。この場合、シリカ粉末の濃度が本発明の範囲より小さいため、透明微粒子の添加効果が認められなかった。光輝性は良好であった。また、乾燥後のインキ皮膜の平均膜厚は、１．２μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１２２】
［比較例９］
シリカ粉末を１５０重量部とする以外は、実施例６と同様にして光輝性インキを調整した。得られた光輝性インキ中の光輝性顔料含有率は１３重量％、シリカ粉末含有率は２２重量％であり、３５℃におけるη_１００は０．６１Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は５％であった。
セル容積８ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調整したインキを薄肉化シームレス缶に印刷した。インキの転移重量は２５ｍｇ／ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は３２％及び平均粒径（Ｄ）は８．４μｍであり、Ｄ^２×Ｓは２３００であった。光輝性は良好であったが、光輝性顔料表面をシリカ微粒子が過剰に覆っているため実施例７に比べると、キラキラ感がやや劣っていた。
また、乾燥後のインキ皮膜の平均膜厚は、１．１μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したところ、光輝感の良い優れた外観であった。
【０１２３】
［比較例１０］
硬度９７度の刷版を使用する以外は、実施例１と同様にして印刷を行った。この場合、光輝性顔料が刷版上に堆積してしまい、一部の微細な光輝性顔料のみが缶に転移している状態となり、印刷の続行は困難であった。
【０１２４】
［比較例１１］
セル容積３ｃｃの彫刻ロールを使用する以外は、実施例１７と同様にして印刷を行った。この場合、転移ムラが大きく外観の悪い印刷となった。また、光輝感も全くなかった。この印刷板にメタルハライドランプを用いて１０００Ｊ／ｍ^２の紫外線を照射し、インキを硬化させたが、この時の硬化インキの平均膜厚は０．１μｍであった。このように、インキ皮膜の平均膜厚が本発明の範囲より小さいと、転移ムラが顕著となり、外観の良い印刷物は得られない。
【０１２５】
［比較例１２］
セル容積６９ｃｃの彫刻ロールを使用する以外は、実施例１７と同様にして印刷を行った。インキ転移重量は１５０ｍｇ／１００ｃｍ^２であった。この場合、光輝感は良好であったが、厚盛り過ぎて画線再現がきわめて悪かった。この印刷板にメタルハライドランプを用いて１０００Ｊ／ｍ^２の紫外線を照射し、インキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は７８％及び平均粒径（Ｄ）は７．０μｍであった。また、Ｄ^２×Ｓは３８００であった。また、硬化後のインキ皮膜の平均膜厚は、１２μｍであった。この印刷板に仕上げワニスを常法に従って塗装・乾燥したところ、画線部と非画線部の段差が目立ち、画線再現の悪さに加えて、著しく外観の悪い印刷物となった。
【０１２６】
［比較例１３］
ステンレス製のカップに液状ポリエステル樹脂（ＮＳ２４００：旭電化工業（株））を２５０重量部入れ、撹拌しながら１５０重量部のジエチレングリコールブチルエーテルアセテートを加えた。次いで、アミノ樹脂（サイメル２３５：三井サイテック（株））１５０重量部と酸触媒（キャタリスト６００：三井サイテック（株））２．０重量部を撹拌しながら加えた後、平均粒径８μｍのノンリーフィングタイプのアルミペースト４５重量部を撹拌しながら加え、アルミ粒子を十分分散させることで光輝性インキを得た。光輝性インキ中の光輝性顔料含有率は５重量％、３５℃におけるη_１００は０．１９Ｐａ・ｓｅｃ、また２２℃の開放雰囲気中に放置した場合の重量減少率は２％であった。
セル容積５ｃｃの彫刻ロールと硬度７０度の刷版を装着した印刷機を用いて、調製したインキを薄肉化シームレス缶に印刷したところ、インキは良好な転移性を示したが、印刷物はキラキラ感も隠蔽感も不足していた。インキ転移重量は９ｍｇ／１００ｃｍ^２であった。この印刷缶を２０５℃で２分間加熱処理することによりインキを硬化させた。光輝性印刷部分の光輝性顔料による被覆面積率（Ｓ）は１５％及び平均粒径（Ｄ）は４．３μｍであり、Ｄ^２×Ｓは２８０であった。また、乾燥後のインキ皮膜の平均膜厚は，０．５μｍであった。この印刷缶に仕上げワニスを常法に従って塗装・乾燥したが、光沢は向上したものの、光輝感の悪さは改善されなかった。
【０１２７】
以上の結果について、インキ特性を表１、表２に、印刷結果を表３、表４に示す。
【０１２８】
【表１】

【０１２９】
【表２】

【０１３０】
【表３】

【０１３１】
【表４】

【０１３２】
【発明の効果】
本発明によれば、光輝性顔料として、平均粒径（レーザ散乱法で測定）が５乃至２５μｍ、特に５乃至２０μｍのアルミフレーク顔料を５乃至４０重量％の量で含有させると共に、３５℃において剪断速度１００ｓｅｃ^−１における見掛け粘度η_１００を２Ｐａ・ｓｅｃ以下とすることにより、形成される印刷インキ層が光輝感に優れていると共に、インキの転移性にも優れていて、再現性のある印刷が可能な印刷インキを提供することができる。
本発明によればまた、上記印刷インキを用い、刷版としてＪＩＳ Ａ硬度９０度以下の硬度を有するものを使用して、刷版上の印刷インキをブランケットに転写し、ブランケット上の印刷インキを被印刷体に転写させることにより、シートや金属缶のような被印刷体に光輝感に優れ且つ印刷再現性に優れた印刷像を形成することが可能な印刷方法が提供される。
本発明によれば更に、前述したインキを用いての印刷によりアルミフレーク顔料を含有する印刷インキ層を設け、且つ前記印刷インキ層の上にクリヤー塗膜を設け、この際、印刷インキ層の平均膜厚を０．２乃至１０μｍ、特に０．３乃至３μｍ、最も好適には０．５乃至２μｍとし、印刷インキ層中に存在する光輝性顔料粒子（アルミフレーク顔料）の面積から算出される平均粒径（Ｄ）を３乃至２０μｍとし且つ光輝性顔料粒子の占める面積率（Ｓ）を１０％以上とすることにより、明るくしかも重厚な光輝感を有し、特異で有用な装飾性と優れた商品価値とを有する印刷包装体が得られる。
【図面の簡単な説明】
【図１】図１は従来の印刷包装体（缶）の断面構造の一例を示す断面図である。
【図２】図２は本発明に用いる缶体の断面構造の一例を示す断面図である。
【図３】図３は本発明に用いる缶体の断面構造の他の例を示す断面図である。
【図４】図４は本発明の印刷包装体の製造に用いる印刷機の概略配置を示す側面図である。
【図５】図５は本発明の印刷包装体の製造に用いる他の印刷機の概略配置を示す側面図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing ink having excellent glitter and excellent ink transferability. More specifically, the present invention relates to a printing ink layer having a bright and heavy glitter feeling with good ink transfer properties. The present invention relates to a printing ink that can be formed on a printing body and a printing method using the same. Furthermore, the present invention also relates to a printed package having a bright and profound radiance, a unique and useful decorative property, and an excellent commercial value.
[0002]
[Prior art]
Various types of printing are performed on the outer surface of the package for the purpose of displaying the contents, their images, or their origins in a design and increasing the commercial value.
For example, as shown in FIG. 1 (known example), the cross-sectional structure of this printed package (can) has a metal substrate 1, and an outer surface called white or size, a base layer 2, a printing ink layer 3, and a finished varnish layer 4. Are sequentially provided.
As the printing ink layer, ink containing glitter pigments such as aluminum flakes and fine particle-coated pearl pigments is also used for the purpose of imparting glitter.
[0003]
In addition, it is also known to use a laminated body of a gravure printing film on a metal material for cans for a can body. For example, Japanese Patent Application Laid-Open No. 7-41740 discloses a thermosetting type metal plate for a can body material. A polyester film that is heat-bonded via a resin-based adhesive to form a protective coating layer, wherein a printed layer made of a resin composition containing a pearl pigment is provided on one surface of the polyester film by gravure printing, A polyester film for covering a can material is described, wherein a thermosetting resin adhesive is provided on a printed layer.
[0004]
Metal cans are roughly classified into three-piece cans with side seams (side seams) in the can body and seamless cans without seams in the can body. In the latter seamless cans, deformation due to plastic flow of the material occurs during draw forming, drawing / ironing forming, drawing / bending / extension forming / ironing forming, so printing on the body of the can body after forming The method of performing is widely adopted.
[0005]
Conventionally, for printing on sheets and seamless cans, a combination of a printing plate and a blanket for receiving an ink layer from the printing plate and transferring it to the body of the can body is used.
As the printing plate, a lithographic plate and a letterpress plate are used.
[0006]
[Problems to be solved by the invention]
However, when printing is performed on printed materials such as sheets and seamless cans using printing inks containing glitter pigments such as aluminum flakes and fine particle-coated pearl pigments, the glitter feeling is insufficient. In addition, there is a disadvantage that the ink transfer from the printing plate to the blanket or the ink transfer from the blanket to the printing medium is not sufficiently performed and the reproducibility of printing is inferior.
[0007]
In the former printing can, the printing ink layer is generally applied to the surface of the can body by an offset method. In the case of ink containing a bright pigment, the dispersion median diameter of the bright pigment in the ink is less than 5 μm. It is quite small, the degree of glitter of the ink layer is dark, and it is still unsatisfactory in the decorative effect obtained.
[0008]
There are two main reasons for this. First, if a bright pigment with a large particle size is used, the bright pigment accumulates at the end of the roll during the transfer of the ink, and the transfer does not proceed smoothly. For example, it is necessary to use a glitter pigment having a small particle diameter, and secondly, a decrease in median diameter occurs when the printing ink is kneaded with a roller.
[0009]
On the other hand, the latter printing can has high brightness, but the process is complicated, and when applied to a two-piece can, there is a drawback that the processability of the film wrap part becomes a problem.
[0010]
Accordingly, an object of the present invention is to provide a printing ink in which the formed printing ink layer is excellent in glitter and has excellent ink transferability and enables reproducible printing.
Another object of the present invention is to provide a printing method capable of forming a printed image having excellent glitter and excellent print reproducibility on a printing medium such as a sheet or a metal can.
Still another object of the present invention is to provide a printed package having a bright and profound radiance, a unique and useful decorative property and an excellent commercial value.
[0011]
[Means for Solving the Problems]
  According to the present invention,Aluminum flake pigment with an average particle size (measured by laser scattering method) of 5 to 25 μmAt a shear rate of 100 sec at 35 ° C.^-1Apparent viscosity η₁₀₀The printing ink is characterized in that is 2 Pa · sec or less.
  In the printing ink of the present invention, the weight reduction rate when left in an open atmosphere at 22 ° C. for 1 hour is preferably 30% or less, and the printing ink has transparent fine particles having an average particle diameter of 0.01 to 1 μm. It is preferable to contain.
  According to the present invention, there is also provided a printing method comprising transferring a printing ink on a printing plate to a blanket, and transferring the printing ink on the blanket to a printing medium.Aluminum flake pigment having an average particle size (measured by laser scattering method) of 5 to 25 μmAt a shear rate of 100 sec at 35 ° C.^-1Apparent viscosity η₁₀₀Is 2 Pa · sec or less and the printing plate is JIS
A printing method characterized by having an A hardness of 90 degrees or less is provided.
  According to the invention,By printing with the printing inkA printing ink layer is provided, and a clear coating film is provided on the printing ink layer, and the average film thickness of the printing ink layer is 0.2 to 10 μm, particularly 0.3 to 3 μm, most preferably 0.5. ~ 2μm, present in the printing ink layerAluminum flake pigmentThe average particle size (D) calculated from the area of the particles is 3 to 20 μm;Aluminum flake pigmentThere is provided a printed package characterized in that the area ratio (S) occupied by the particles is 10% or more.
  In the package of the present invention, the average particle diameter (D) and the area ratio (S) are expressed by the formula D²It is preferable that the relationship satisfies xS ≧ 300.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
[Printing ink]
  The printing ink of the present invention isAn aluminum flake pigment is contained as a bright pigment.Aluminum flake pigment present in printing ink gives metallic reflected light, that is, front reflected light, to incident light.Gives the printing ink layer a lustrous appearance.
[0013]
  In the printing ink of the present invention,Aluminum flake pigment (hereinafter sometimes referred to as “bright pigment”)It is important that the average particle size (measured by a laser scattering method) is in the range of 5 to 25 μm in order to develop a bright and balanced glitter. That is, in order to give an excellent glitter feeling, the glitter pigment particles are required to have a certain size.
[0014]
As will be described later, when the average particle diameter of the glitter pigment is less than the above range, the printing ink layer tends to be dark overall and the glitter feeling tends to be poor (Comparative Example 1), while the average particle diameter is within the above range. When the ratio is more than 1, the difference between the portion with and without the glitter pigment becomes noticeable, and a balanced glitter feeling cannot be obtained (Comparative Example 2).
[0015]
It is also important that the luster pigment is present in the ink at a concentration of 5 to 40% by weight. That is, when the concentration of the glitter pigment is lower than the above range, the glitter feeling tends to be insufficient as compared with the case of being within the above range (Comparative Example 3), whereas when the concentration of the glitter pigment exceeds the above range. As compared with the case of being in the above range, the transferability of the ink is remarkably deteriorated, and it becomes difficult to obtain a good printed matter having high glitter (Comparative Example 4).
[0016]
The printing ink of the present invention has a shear rate of 100 sec at 35 ° C.^-1Apparent viscosity η₁₀₀It is particularly important that is 2 Pa · sec or less.
The apparent viscosity was measured at 35 ° C. with a shear rate of 100 sec.^-1This is because it is determined that the above conditions are close to the actual printing conditions.
This apparent viscosity η₁₀₀Is closely related to both the transferability of printing ink and the appearance of glitter.
That is, apparent viscosity η₁₀₀If it exceeds 2 Pa · sec, as shown in Comparative Example 5 described later, ink is deposited on the printing plate and printing is performed in a thick state, resulting in image thickening and poor print reproducibility.
[0017]
  Also,The aluminum flake pigment used as the glitter pigment is the same as other glitter pigments such as fine particle coated pearl pigments.It has a flat particle shape, and when these particles are arranged parallel to the printing surface, the most excellent glitter is exhibited, but the apparent viscosity η₁₀₀When the value exceeds the above range, the orientation of the glitter pigment particles is inhibited, and the glitter feeling is also lowered.
[0018]
In the present invention, it is necessary that the transfer of ink from the printing plate to the blanket and the transfer of ink from the blanket to the printing surface of the substrate are smoothly performed.
For this reason, it is desirable that the weight reduction rate when left in an open atmosphere at 22 ° C. for 1 hour is 30% or less. When the weight reduction rate exceeds 30% by weight, the printing ink is deposited on the printing plate or the blanket, and there is a tendency for the ink to transfer poorly to the printing medium (Comparative Example 6).
[0019]
The printing ink of the present invention preferably contains transparent fine particles having an average particle diameter of 0.01 to 1 μm. By including the above-mentioned transparent fine particles in the printing ink, the glitter pigment particles are easily dispersed in the paint, and the glitter and sharpness of the printing ink layer are remarkably improved and the transferability of the ink is also improved. .
[0020]
  In the present invention,Aluminum flake pigments used as glitter pigmentsIt has an average particle diameter (median diameter) determined by the light scattering method in the above-mentioned range.The glitter pigment particlesIt is flat and has a tendency to be oriented parallel to the surface direction during printing,Has a unique metallic luster.Luster pigment(Aluminum flake pigment)The flatness scale is generally represented by an aspect ratio obtained by dividing the average particle diameter by the thickness of the particle. In order to ensure a high degree of orientation during printing, the aspect ratio is in the range of 10 to 500. Is desirable.
[0021]
As aluminum flakes, a leafing type and a non-leafing type are known. The leafing type is treated with a higher fatty acid such as stearic acid and tends to float on the surface of the ink layer, but tends to lack a slightly glittery feeling. On the other hand, the non-leafing type does not tend to float on the surface of the ink layer and has a strong glitter feeling depending on the viewing angle. In the present invention, any of these can be used, but it is preferable to use a non-leafing type, and if desired, a leafing type can be mixed and used.
In addition, so-called colored aluminum flakes can be used, in which fine particles or colored substances are adhered to aluminum flakes to develop a metallic feeling with a unique color tone.
[0024]
Mica titanium pigment is mica (3Al₂O₃・ K₂O · 6SiO₂・ NH₂O) flaky crystals are used as nuclei, titanium oxide hydrate is deposited on the nuclei, and this is fired to obtain titanium dioxide. The surface titanium dioxide layer may be anatase type or rutile type.
Mica is characterized by being a flaky crystal having a cleavage property, a thickness of 1 μm or less and an aspect ratio of 50 or more, and a thin layer of a titanium pigment having a high refractive index is formed on this surface. As a result, chromatic interference colors as shown in the above table can be obtained according to the layer thickness.
[0025]
[Printing ink composition]
The printing ink used in the present invention is obtained by dispersing the above-mentioned glitter pigment in a vehicle and additives together with other colorants as required.
[0026]
As the vehicle, oil, resin, solvent, plasticizer and the like are used.
As the oils, linseed oil that is a dry oil, boiled linseed oil, soybean oil that is a semi-dry oil, castor oil that is a non-drying oil, etc. are used alone or in combination, and these oils are also described later. It is also used for resin modification.
Examples of resins include natural resins such as rosin, modified rosin, and gilsonite, and the following synthetic resins such as phenol resins, alkyd resins, xylene resins, urea resins, melamine resins, polyester resins, polyamide resins, acrylic resins, epoxy resins, A ketone resin, a benzoguanamine resin, a petroleum resin, a vinyl chloride resin, a vinyl acetate resin, a chlorinated polypropylene, a chlorinated rubber, a cyclized rubber, a cellulose derivative and the like are used alone or in combination of two or more.
As the solvent, toluene, methyl ethyl ketone (MEK), solvent naphtha, or the like is used.
As the plasticizer, plasticizers such as phthalate ester, adipate ester, citrate ester, and polyester are used.
[0027]
On the other hand, as additives, natural or synthetic waxes, drying agents, dispersing agents, wetting agents, crosslinking agents, gelling agents, thickening agents, anti-skinning agents, stabilizers, matting agents, antifoaming agents, A photopolymerization initiator or the like is used.
[0028]
As the colorant, known dyes and pigments are used. A suitable example is as follows.
(Black dye / pigment)
Carbon black, acetylene black, run black, aniline black, nigrosine black.
(Yellow dye / pigment)
Zinc Yellow, Cadmium Yellow, Yellow Iron Oxide, Mineral Fast Yellow, Nickel Titanium Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG , Tartrage rake.
(Orange color pigment)
Red mouth yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK.
(Red dye / pigment)
Bengala, cadmium red, red lead, mercury cadmium sulfide, permanent red 4R, risor red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, brilliant carmine 3B.
(Purple dyes)
Manganese purple, fast violet B, methyl violet lake.
(Blue dye / pigment)
Bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, fast sky blue, induslen blue BC.
(Green dye / pigment)
Chrome green, chromium oxide, pigment green B, malachite green lake, fanal yellow green G.
(White pigment)
Zinc white, titanium oxide, antimony white, zinc sulfide.
(External pigment)
Barite powder, barium carbonate, clay, silica, white carbon, talc, alumina white.
As these pigments, flash pigments are preferably used from the viewpoint of dispersibility.
[0029]
The ink vehicle used may be heat curable or ultraviolet curable.
As the thermosetting type, an ink using an alkyd type or polyester type vehicle is suitable.
The alkyd-type or polyester-type vehicle comprises (i) at least one polyhydric alcohol, such as glycerin, pentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, sorbitol, mannitol, trimethylolpropane, and (ii) Polybasic acids such as phthalic anhydride, isophthalic acid, maleic acid, fumaric acid, sebacic acid, adipic acid, citric acid, tartaric acid, malic acid, diphenic acid, 1,8 naphthalic acid, terpene oil, rosin, (Iii) fatty oils or fatty acids, such as linseed oil, soybean oil, egoma oil, fish oil, tung oil, sunflower oil, walnut oil, oil deer oil, castor oil, dehydrated castor oil, and distillation, if necessary Fatty acids, cottonseed oil, coconut oil, or these fats This resin is modified with fatty acid or monoglyceride of fatty acid. This resin is further modified with rosin, non-drying fatty acid, urea melamine resin, drying oil fatty acid, carboxylic acid resin, maleic acid resin, ester rosin, etc. It is also used in the form of natural resin modification.
[0030]
As the hardener, metal soaps of various metals such as lead, cobalt, zinc and manganese, naphthenates and the like are used.
[0031]
Moreover, what melt | dissolved resins, such as an amino resin and an acrylic resin, in reactive diluents, such as a polyfunctional acryl-type monomer, can also be used suitably as another example of a thermosetting type. These vehicle compositions are used in combination with a thermal polymerization initiator, if necessary.
The polyfunctional acrylic monomer is a (meth) acrylate of an alkylene oxide-modified polyhydric alcohol having 2 or more, particularly 3 or more (meth) acryloyl groups in the molecule, represented by the following general formula (1). Are preferred.

In the formula, Z is a residue of a polyhydric alcohol, R is an alkylene group having 2 to 4 carbon atoms, R₁Is a hydrogen atom or a methyl group, n is a number of 1 or more, m is a number of 2 or more, particularly 3 or more, and p is a number of 1 or less including zero.
Examples of the polyhydric alcohol from which the (meth) acrylate of formula (1) is derived include trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, glycerin, diglycerin, trimethylolethane, ditrimethylolethane, erythritol, Xylitol, mannitol, sorbitol and the like can be mentioned, but of course not limited thereto.
As the alkylene oxide used for the modification of the polyhydric alcohol, ethylene oxide is suitable, but other alkylene oxides such as propylene oxide can also be used.
[0032]
As the thermal polymerization initiator, an organic peroxide or an azo compound can be used.
Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, and 2,5-dimethyl-2,5. -Bis (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy) valerate, benzoyl-peroxide, t-butyl Peroxybenzoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide and 2,4-dichlorobenzoyl peroxide, m-toluyl A peroxide etc. are mentioned.
Examples of the azo compound include azoisobutyronitrile and dimethylazoisobutyronitrile.
[0033]
As the ultraviolet curable material, either an ultraviolet radical polymerization type or an ultraviolet cation polymerization type may be used.
As the ultraviolet radical polymerization type, a combination of an acrylic monomer or a prepolymer and a photo radical polymerization catalyst is used. As the acrylic monomer or prepolymer, a monomer or prepolymer having a plurality of (meth) acryloyl groups in the molecule or a mixture thereof is used.
Representative examples of the photoradical polymerization catalyst include benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, and xanthones.
As the ultraviolet cationic polymerization type, for example, a combination of an ultraviolet curable epoxy resin and a photocationic polymerization catalyst is used.
The ultraviolet curable epoxy resin contains an epoxy resin component having an alicyclic group in the molecule and an adjacent carbon atom of the alicyclic group forming an oxirane ring. For example, at least 1 in the molecule An epoxy compound having an epoxycycloalkane group, for example, an epoxycyclohexane ring, an epoxycyclopentane ring, or the like is used alone or in combination.
Suitable examples include, but are not limited to, vinylcyclohexene diepoxide, vinylcyclohexene monoepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 2- (3,4-epoxycyclohexyl). -5,5-spiro-3,4-epoxy) cyclohexane-m-dioxane, bis (3,4-epoxycyclohexyl) adipate, limonene dioxide and the like.
The cationic ultraviolet polymerization initiator used in combination with the epoxy resin is one that decomposes by ultraviolet rays, releases a Lewis acid, and this Lewis acid has a function of polymerizing an epoxy group. For example, aromatic iodonium And salts, aromatic sulfonium salts, aromatic selenium salts, aromatic diazonium salts, and the like.
[0034]
The printing ink layer of the present invention contains transparent fine particles having an average primary particle diameter of 0.01 to 1 μm, suppresses aggregation of the glitter pigment, improves its dispersibility, and transfers the ink. It is preferable in terms of improving the brightness and further improving the surface orientation and improving the glitter. The effect of increasing the orientation of the glitter pigment can also be obtained by blending the above-mentioned colored pigment, but by blending transparent fine particles with a predetermined average particle diameter, the glitter can be achieved without changing the color tone of the printing ink layer. The orientation of the pigment can be increased.
[0035]
The transparent fine particles may be made of resin or inorganic transparent fine particles such as amorphous silica.
In the former case, the fine particles may be spherical particles having a particle diameter of 0.01 to 1 μm produced by an emulsion polymerization method or a non-emulsifier emulsion polymerization method. It is produced by emulsion polymerization so as to be in the range of 0.01 to 1 μm.
The monomer is generally a lipophilic and radically polymerizable monomer, and examples thereof include vinyl aromatic monomers, acrylic monomers, vinyl ether monomers, and the like.
Examples of the vinyl aromatic monomer include styrene, α-chlorostyrene, o, m, p-chlorostyrene, p-ethylenestyrene, divinylbenzene, and the like.
Examples of the acrylic monomer include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4- Examples include hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate.
Examples of vinyl ether monomers include vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether, and the like.
Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.
Examples of the monoolefin monomer include ethylene, propylene, isobutylene-1, butene-1, pentene-1, 4-methylpentene-1.
The monomer is a non-polar monomer, but can be used by copolymerizing with a cationic monomer or an anionic monomer as desired for controlling the dispersibility of the fine particles, or a crosslinking monomer for preventing dissolution. It can be used after being copolymerized with.
Examples of the cationic monomer include monomers containing a cationic group such as a basic nitrogen atom, such as dimethylamino acrylate, dimethylaminoethyl acrylate, diethylaminopropyl acrylate, N-aminoethylaminopropyl acrylate, dimethylamino methacrylate, dimethylamino. Primary, secondary or tertiary amino groups such as ethyl methacrylate, diethylaminopropyl methacrylate, N-aminoethylaminopropyl methacrylate, vinylpyridine, 2-vinylimidazole, 2-hydroxy-3-acryloxypropylmethylammonium chloride, acrylonitrile Alternatively, a monomer containing a quaternary ammonium group is used.
As an anionic monomer, a monomer having an anionic property such as sulfonic acid, carboxylic acid, phosphonic acid or a salt thereof, preferably a monomer having a group of sulfonic acid or a salt thereof such as styrene sulfonic acid, vinyl sulfonic acid, Acrylic sulfonic acid, acrylamidomethylpropane sulfonic acid, acrylic sulfonic acid, methacryl sulfonic acid, acryl-2-ethyl sulfonic acid, methacryl-2-ethyl sulfonic acid and the like, and salts thereof such as sodium, potassium, calcium and the like can be mentioned.
Examples of the crosslinkable monomer include divinylbenzene (DVB), diallyl phthalate (DAP), and triallyl isocyanurate.
[0036]
The inorganic transparent fine particles include amorphous silica, particularly amorphous silica obtained by a dry method (thermal decomposition of silicon tetrachloride), and amorphous silica obtained by a wet method satisfying the above-mentioned particle size. Is used.
[0037]
In the printing ink of the present invention, the glitter pigment is desirably contained at a concentration of 5 to 40% by weight, particularly 7 to 35% by weight. That is, when the concentration of the glitter pigment is less than 5% by weight, the glitter feeling tends to be insufficient as compared with the case of being within the range of the present invention (Comparative Example 3), while the concentration of the glitter pigment is 40. When the content exceeds 5% by weight, the transferability of the ink is remarkably deteriorated as compared with the case where it is within the range of the present invention, and it becomes difficult to obtain a good printed matter having high glitter (Comparative Example 4).
The transparent fine particles are desirably contained at a concentration of 0.5 to 20% by weight, particularly 1 to 10% by weight. That is, when the concentration of the transparent fine particles is less than 0.5% by weight, the effect of the dispersibility of the glitter pigment particles, the ease of dispersal, and the transferability of the ink is significantly higher than when no transparent fine particles are added. Is not expressed (Comparative Example 8). On the other hand, when the concentration of the transparent fine particles exceeds 20% by weight, there is no improvement in the dispersibility, ease of dispersal, and ink transferability of the glitter pigment particles as compared with the case in the range of the present invention. There exists a tendency for a feeling to fall (Comparative Example 9).
This printing ink has a shear rate of 100 sec at 35 ° C.^-1Apparent viscosity η₁₀₀Is preferably 2 Pa · sec or less, particularly 0.05 to 1 Pa · sec. That is, η₁₀₀Is over 2 Pa · sec, η₁₀₀As compared with the case where the ink is in the range of the present invention, the ink tends to be accumulated on the printing plate, and the printed material has a poorly reproducible thickness as a whole (Comparative Example 5).
[0038]
[Substrate]
The printing ink of the present invention is used for printing on various substrates, especially metal cans, plastic cans, metal caps, plastic caps, glass bottles, plastic bottles, plastic cups, plastic tube containers, various pouches, in-mold labels for bottles, etc. Applicable to.
The present invention can be advantageously applied to any metal can body known per se, such as a two-piece can and a three-piece can.
Of these metal cans, two-piece cans (seamless cans) formed by drawing / deep drawing, drawing / ironing forming, drawing / bending-extension forming / ironing forming of metal or coated metal, It is customary to perform external surface printing, and the present invention is useful for imparting glitter by such external surface printing on a can.
Therefore, the present invention will be described with reference to this two-piece can, but the present invention is of course not limited to this example.
[0039]
The two-piece can used for printing in the present invention is manufactured by drawing-redrawing processing, drawing-squeezing processing or drawing-bending-drawing processing-ironing processing of a metal material or an organic-coated metal material. An organic coated metal plate formed into a cup or a metal cup provided with an organic coating later may be used, but an organic coated metal plate formed into a cup is easy and easy to manufacture. Is preferred.
[0040]
In FIG. 2 which shows an example of the cross-sectional structure of this two-piece can, this cup 10 includes a metal substrate 11, an inner surface organic coating 12 provided on the inner surface thereof, and an outer surface organic coating 13 provided on the other surface of the substrate. Consists of.
In FIG. 3, which shows another example of the cross-sectional structure, an inner surface organic coating 12a is applied to the metal base 11 formed into a cup later by painting, and a special organic material is provided on the outer surface of the metal base 11. A coating is not formed, but the outer surface is painted and printed, such as a white coat, as pointed out earlier and detailed below.
[0041]
In the present invention, as the metal plate, various surface-treated steel plates and light metal plates such as aluminum are used.
As the surface treated steel sheet, a cold-rolled steel sheet is subjected to secondary cold rolling after annealing and subjected to one or more surface treatments such as galvanization, tin plating, nickel plating, electrolytic chromic acid treatment, and chromic acid treatment. Can be used. An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet, particularly 10 to 200 mg / m.²1-50mg / m of metal chromium layer²And a chromium oxide layer (in terms of chromium metal), which has an excellent combination of coating film adhesion and corrosion resistance.
Other examples of surface-treated steel sheets are 0.5 to 11.2 g / m²It is a hard tin plate having a tin plating amount of This tin plate has a chromium content of 1 to 30 mg / m in terms of metal chromium.²It is desirable that chromic acid treatment or chromic acid / phosphoric acid treatment is performed. As yet another example, an aluminum-coated steel sheet subjected to aluminum plating, aluminum pressure welding, or the like is used.
[0042]
As the light metal plate, an aluminum alloy plate is used in addition to a so-called pure aluminum plate. An aluminum alloy plate excellent in terms of corrosion resistance and workability is Mn 0.2 to 1.5 wt%, Mg 0.8 to 5 wt%, Zn 0.25 to 0.3 wt%, and Cu It has a composition of 0.15 to 0.25% by weight and the balance is Al. These light metal plates also have a chromium content of 20 to 300 mg / m in terms of metal chromium.²It is desirable that chromic acid treatment or chromic acid / phosphoric acid treatment is performed.
[0043]
The thickness of the base plate of the metal plate, that is, the thickness (tB) of the can bottom varies depending on the type of metal, the use or size of the container, and generally has a thickness of 0.10 to 0.5 mm. However, in the case of a surface-treated steel plate, it is preferable to have a thickness of 0.10 to 0.3 mm, and in the case of a light metal plate, a thickness of 0.15 to 0.40 mm.
[0044]
The organic coating optionally provided on the metal substrate may be a thermoplastic resin, a thermosetting resin or a composition thereof, but in general, a thermoplastic resin is preferred. When the metal substrate is an aluminum-based substrate, the resin coating on the outer surface may be omitted as shown in FIG.
[0045]
The thermoplastic resin coated on the metal plate is preferably a crystalline thermoplastic resin, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic ester. Olefin-based resin films such as copolymers and ionomers; Polyesters such as polyethylene terephthalate, polybutylene terephthalate and ethylene terephthalate / isophthalate copolymers; Polyamides such as nylon 6, nylon 6,6, nylon 11 and nylon 12; Polychlorinated Vinyl; polyvinylidene chloride and the like.
[0046]
The thermoplastic resin coating layer may contain an inorganic filler (pigment) for the purpose of concealing the metal plate and assisting the transmission of the wrinkle pressing force to the metal plate during drawing-redraw molding. Further, this film may be blended with known film compounding agents, for example, antiblocking agents such as amorphous silica, various antistatic agents, lubricants, antioxidants, ultraviolet absorbers, and the like according to known formulations. it can.
[0047]
Inorganic fillers include rutile or anatase type inorganic white pigments such as titanium dioxide, zinc white, gloss white, etc .; barite, precipitated barium sulfate, calcium carbonate, gypsum, precipitated silica, aerosil, talc, fired or unfired White extender pigments such as clay, barium carbonate, alumina white, synthetic or natural mica, synthetic calcium silicate, magnesium carbonate; black pigments such as carbon black and magnetite; red pigments such as Bengala; yellow pigments such as Siena; A blue pigment such as cobalt blue can be mentioned. These inorganic fillers can be blended in an amount of 10 to 500% by weight, particularly 10 to 300% by weight per resin.
[0048]
The coating of the coated thermoplastic resin to the metal plate is performed by heat fusion method, dry lamination, extrusion coating method, etc. When the adhesiveness (heat fusion property) between the coating resin and the metal plate is poor For example, urethane adhesives, epoxy adhesives, acid-modified olefin resin adhesives, copolyamide adhesives, copolyester adhesives, and the like can be interposed.
[0049]
The thickness of the thermoplastic resin is generally in the range of 3 to 50 μm, particularly 5 to 40 μm. In the case of heat fusion using a film, it may be unstretched or stretched.
[0050]
As a particularly suitable film, a polyester mainly composed of ethylene terephthalate units or butylene terephthalate units is formed into a film by a T-die method or an inflation film forming method, and this film is sequentially or simultaneously biaxially stretched at a stretching temperature, The film manufactured by heat-setting the film after extending | stretching can be mentioned.
[0051]
Polyethylene terephthalate itself can be used as the raw material polyester, but lowering the maximum crystallinity that the film can reach is desirable in terms of impact resistance and workability. For this purpose, polyester other than ethylene terephthalate is desirable. It is preferable to introduce the copolymerized ester unit. It is particularly preferable to use a biaxially stretched film of a copolyester having a melting point of 210 to 252 ° C. mainly composed of ethylene terephthalate units or butylene terephthalate units and containing a small amount of other ester units. The melting point of homopolyethylene terephthalate is generally 255 to 265 ° C.
[0052]
In general, 70 mol% or more, particularly 75 mol% or more of the dibasic acid component in the copolyester is composed of a terephthalic acid component, and 70 mol% or more, particularly 75 mol% or more of the diol component is composed of ethylene glycol or butylene glycol, It is preferable that 1 to 30 mol%, particularly 5 to 25 mol% of the dibasic acid component is composed of a dibasic acid component other than terephthalic acid.
[0053]
Dibasic acids other than terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalenedicarboxylic acid: alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid: succinic acid, adipic acid, sebacic acid, dodecanedioic acid, etc. Or a combination of two or more of the aliphatic dicarboxylic acids: As the diol component other than ethylene glycol or butylene glycol, propylene glycol, diethylene glycol, 1,6-hexylene glycol, cyclohexane dimethanol, bisphenol A 1 type, or 2 or more types, such as an ethylene oxide adduct. Of course, the combination of these comonomers is preferably such that the melting point of the copolyester is within the above range.
[0054]
The polyester or copolyester used should have a molecular weight sufficient to form a film, for which purpose the intrinsic viscosity (IV) is 0.55 to 1.9 dl / g, in particular 0.65 to 1.4 dl / g. Those in the range of are desirable.
[0055]
The film is generally stretched at a temperature of 80 to 110 ° C. and an area stretch ratio of 2.5 to 16.0, particularly 4.0 to 14.0. It is good to carry out in the range of 240 ° C., particularly 150 to 230 ° C.
[0056]
When laminating, in order to prevent excessive crystallization, the time for the laminated film to pass through the crystallization temperature range is made as short as possible, and preferably this temperature range is passed within 10 seconds, especially within 5 seconds. To do. For this purpose, only the metal material is heated at the time of lamination, and the laminate is forcibly cooled immediately after film lamination. For cooling, direct contact with cold air or cold water or pressure contact of a cooled cooling roller is used. It should be understood that the degree of crystal orientation can be relaxed if the film is heated to a temperature close to the melting point during the lamination and then rapidly cooled after the lamination.
[0057]
When using an adhesion primer, it is generally desirable to corona discharge the surface of the film in order to improve adhesion to the adhesion primer to the film. The degree of corona discharge treatment is preferably such that the wetting tension is 44 dyne / cm or more.
[0058]
In addition, it is also possible to perform known adhesion improving surface treatments such as plasma treatment and flame treatment on the film, and adhesion improving coating treatments such as urethane resin and modified polyester resin.
[0059]
The adhesion primer provided as desired between the polyester film and the metal material exhibits excellent adhesion to both the metal material and the film. A typical primer paint excellent in adhesion and corrosion resistance is a phenol epoxy paint comprising a resol type phenol aldehyde resin derived from various phenols and formaldehyde, and a bisphenol type epoxy resin. In particular, it is a paint containing a phenol resin and an epoxy resin in a weight ratio of 50:50 to 5:95, particularly 40:60 to 10:90.
[0060]
The adhesive primer layer is generally preferably provided with a thickness of 0.3 to 5 μm. The adhesion primer layer may be provided on a metal material in advance or may be provided on a polyester film in advance.
[0061]
The polyester layer serving as a metal coating can be provided by so-called extrusion coating instead of being applied in the form of a biaxially stretched film. In this extrusion coating method, a web of molten resin extruded from a die is supplied onto a heated metal substrate, and after pressing with a laminating roll, it is immediately cooled.
[0062]
Examples of the thermosetting resin paint used for coating include phenol-formaldehyde resin, furan-formaldehyde resin, xylene-formaldehyde resin, ketone-formaldehyde resin, urea formaldehyde resin, melamine-formaldehyde resin, alkyd resin, unsaturated polyester resin, Epoxy resin, bismaleimide resin, triallyl cyanurate resin, thermosetting acrylic resin, silicone resin, oil-based resin, or the above thermosetting resin and thermoplastic resin paint such as vinyl chloride-vinyl acetate copolymer, chloride Examples thereof include a vinyl-maleic acid copolymer, a vinyl chloride-maleic acid-vinyl acetate copolymer, an acrylic polymer, and a composition with a saturated polyester resin. These resin paints may be used alone or in combination of two or more.
Among the thermosetting resin coatings, a combination of an epoxy resin (a) and a curing agent resin (b) for the epoxy resin is preferable.
Among these curing agent resins, it is desirable to use a phenol-aldehyde resin component containing a phenol formaldehyde resin, particularly a polycyclic polyhydric phenol, in terms of adhesion to a film, barrier property against a corrosive component, and processing resistance. .
[0063]
Forming into a two-piece can (seamless can) is performed by means known per se, such as drawing-redrawing, drawing-redrawing-ironing, drawing-bending-redrawing, drawing-bending-drawing-ironing, etc. Is called.
[0064]
For example, according to deep drawing (drawing-redrawing), a predrawing cup formed from a coated metal plate is formed by an annular holding member inserted into the cup and a redrawing die located below the holding member. Hold. The redraw punch is disposed so as to be coaxial with the holding member and the redrawing die and to be able to enter and leave the holding member. The redraw punch and the redraw die are moved relative to each other so as to engage each other.
Thereby, the side wall portion of the front drawn cup is bent perpendicularly inward from the outer peripheral surface of the annular holding member through the curvature corner portion thereof, and is defined by the annular bottom surface of the annular holding member and the upper surface of the redraw die. It can be formed into a deep drawn cup having a diameter smaller than that of the front drawn cup by being bent substantially perpendicular to the axial direction by the action corner portion of the redraw die.
[0065]
Further, the radius of curvature (Rd) of the working corner portion of the redrawing die is set to 1 to 2.9 times, particularly 1.5 to 2.9 times the thickness of the metal plate base plate (tB). It is possible to effectively reduce the thickness by bending and stretching the part. In addition, the variation in thickness between the lower part and the upper part of the side wall part is eliminated, and a uniform thinning can be achieved throughout. In general, the side wall of the can body has a thickness reduction rate (thickness variation rate) of 5 to 45% (-5 to -45%), particularly 5 to 40% (-5 to -40%) with respect to the base plate thickness (tB). ).
[0066]
For deep-drawn cans, the following formula (1)
[Formula 1]

Where D is the sheared laminate diameter,
d is the punch diameter,
The aperture ratio RD defined by is preferably in the range of 1.1 to 3.0 in one stage and in the range of 1.5 to 5.0 in total.
[0067]
In addition, an ironing die is disposed behind the redrawing or bending / redrawing redrawing, and the following equation (2) is applied to the side wall portion.
[Formula 2]

In the formula, tB is the thickness of the base plate, and tW is the thickness of the side wall.
It is also possible to reduce the thickness by ironing so that the ironing ratio RI defined by the above formula is 5 to 70%, particularly 10 to 60%.
[0068]
When drawing, etc., various types of lubricants such as liquid paraffin, synthetic paraffin, edible oil, hydrogenated edible oil, palm oil, various natural waxes, polyethylene wax are applied to the coated metal plate or cup. Good. The amount of lubricant applied varies depending on the type, but is generally 0.1 to 10 mg / dm.², Especially 0.2-5mg / dm²The lubricant is applied by spray-coating it on the surface in a molten state.
[0069]
In order to improve the drawability of the cup, the temperature of the resin-coated drawn cup is set in advance within the range of the glass transition point (Tg) of the coated resin, particularly within the thermal crystallization temperature, and the plastic flow of the resin-coated layer is reduced. It is advantageous to mold in an easy state.
[0070]
The inner surface-side organic coated metal cup after molding is subjected to a printing process after so-called trimming for cutting the ear portion of the cup opening. Prior to this trimming process, the molded cup can be heated to a temperature higher than the glass transition point (Tg) of the coating resin and lower than the melting point, thereby relaxing the distortion of the coating resin. This operation is particularly effective in the case of a thermoplastic resin in order to improve the adhesion between the coating and the metal.
[0071]
[printing]
  In the present invention,Aluminum flake pigment having an average particle size of 5 to 25 μm as a bright pigmentAt a shear rate at 35 ° C.100 sec ^-1 Apparent viscosity atη ₁₀₀ The printing ink on the printing plate is transferred to the blanket using the printing letterpress with a JISA hardness of 90 degrees or less using the printing ink with a 2 Pa · sec or less, and the printing ink on the blanket is printed. Printing on the substrate to be printed. In this printing, the average thickness of the printing ink layer becomes 0.2 to 10 μm, and the bright pigment particles are contained in the printing ink layer.(Aluminum flake pigment)It is desirable to perform printing so that the area ratio (S) occupied by is 10% or more, particularly 20% or more.
[0072]
The film thickness of the printing ink layer can be easily adjusted by known means such as adjusting the amount of ink transferred to the printing plate.
Further, in order to increase the area ratio (S) occupied by the glitter pigment particles, the transition to the printing plate is performed uniformly and the glitter pigment particles are oriented in the plane direction ( The area in the surface direction increases.)
[0073]
Engraving roller with engraved grooves on the surface (slanted engraving roller) or engraving with microscopic holes on the surface to draw ink from the ink pan to effectively transfer ink to the printing plate It is effective to use a roller (lattice engraving roller). By using these engraving rollers, the glitter pigment particles are not crushed even when the plate cylinder and the pumping roller are in pressure contact, and the ink transfer from the pumping roller to the plate cylinder proceeds smoothly. Furthermore, an extremely advantageous action is achieved in that the tendency of the glitter pigment particles to be oriented in the plane direction is increased.
[0074]
In the case of the oblique engraving roller, grooves are formed in parallel lines with a constant interval of 25 to less than 90 degrees, particularly 45 to 85 degrees with respect to the roller axis. The depth of the groove varies depending on the viscosity of the printing ink, but is generally in the range of 10 to 60 μm, particularly 10 to 40 μm. The groove pitch is generally in the range of 80 to 300 lines / inch, particularly 120 to 275 lines / inch, and the groove width is preferably in the range of 80 to 200 μm, although it varies depending on the number of lines. .
On the other hand, in the case of a lattice-type engraving roller, a large number of micro holes (cells) having a trapezoidal cross section are provided in a lattice-like portion formed by a group of parallel lines intersecting each other in two directions. The depth of the hole varies depending on the viscosity of the printing ink, but is generally in the range of 10 to 40 μm, particularly 10 to 30 μm. The pitch of the grating is generally in the range of 80 to 300 lines / inch, particularly 120 to 250 lines / inch. The angle formed with respect to the roller axis of the group of parallel lines intersecting in two directions is in the range of 25 to 75 degrees, particularly 30 to 60 degrees in one direction, and 335 to 285 degrees, particularly 330 to 300 in the other direction. It should be in the range of degrees, and should be the target for the parallel lines in two directions and the roller axis. The material of the engraving roller is not particularly limited, but is generally made of steel.
The cell volume of the lattice engraving roller is generally 6 to 18 cc / m.²Those in the range of are desirable.
A suitable engraving roller is available under the trade name Anilox Roller.
[0075]
In FIG. 4 which shows the schematic structure of the printing press used in the present invention, the glitter pigment-containing ink is accommodated in the ink pan 21, and an engraving pumping roller 23 is rotatably provided so as to be in contact with the ink. . A doctor blade 24 for controlling the thickness of the ink layer is disposed around the engraving pumping roller 23, and a plate cylinder 25 is provided so as to contact the engraving pumping roller 23. Further, a blanket cylinder 26 for receiving the ink layer from the plate cylinder 25 and transferring it to the outer surface of the can body is provided so as to contact the plate cylinder 25.
The glitter pigment-containing ink in the pan 21 is held on the surface of the engraving pumping roller 23, pumped up, adjusted in thickness by contact with the doctor blade 24, contacted with the plate cylinder 25, and an image line of the plate cylinder 25. It is applied to the part. The ink layer on the plate cylinder is then transferred to the surface of the blanket cylinder 26, and the ink layer on the blanket 26 is transferred to a can (not shown) in contact with the blanket cylinder to form a printed image.
As the printing plate for the plate cylinder 25, a resin relief plate is used. The hardness of the resin letterpress is particularly important, and a resin letterpress having a hardness of 90 degrees or less determined by a JISA hardness tester is preferably used. When the hardness of the printing plate is greater than 90 degrees, a bright pigment having a large particle size is deposited on the printing plate, resulting in poor transfer (Comparative Example 10). A suitable example of such a low-hardness printing plate is a resin plate for flexographic printing.
[0076]
In the printing machine shown in FIG. 4, the ink layer pumped up by the engraving pumping roller 23 is supplied to the printing plate of the plate cylinder 25, but a rubber roller is interposed between the engraving pumping roller 23 and the plate cylinder 25 and pumped up. The ink layer may be supplied to the printing plate via a rubber roller.
[0077]
In the printing machine shown in FIG. 4, the ink is pumped from the ink pan 21 by the engraving pumping roller 23, but a known ink chamber 27 may be used in flexographic printing instead of the ink pan 21. In particular, the ink chamber 27 is suitable for high-speed printing with less ink scattering. FIG. 5 shows an example of this configuration.
[0078]
In the printing method according to the present invention, it is preferable to provide a clear coating film on the printing ink layer. That is, in the present invention, since the printing ink layer is applied to the outer surface of the printing material by an offset method or the like, it is essential to protect the outer surface of the printing ink layer with the clear coating film.
This clear coating not only mechanically protects the printing ink layer from scratching and peeling, but also has an auxiliary effect of improving the glitter by preventing irregular reflection from the outer surface of the printing ink layer. ing.
[0079]
As the clear coating film applied on the printing ink layer, a so-called finishing varnish is generally used in the field of can printing. As this clear coating film, among the resins described for the printing ink, those having excellent transparency are used without the addition of a luster pigment or a colorant. Any of them may be used.
[0080]
The thickness of the clear coating film is not particularly limited as long as the printing ink layer can be sufficiently protected, but it is generally preferably 3 to 10 μm, particularly 4 to 6 μm.
On the other hand, the clear coating film is formed in the same manner by using an applicator roller instead of the plate cylinder 25 in the printing machine shown in FIG. 4 and bringing the applicator roller into contact with the printed outer surface of the can body. .
[0081]
The formation of the printing ink layer and the formation of the clear coating film can be performed in a so-called wet-on-wet relationship. After the printing ink layer is cured, the formation of the clear coating film is performed by the so-called wet coating. It can also be done in an on-dry relationship.
[0082]
For curing the printing ink layer and the clear coating film, a temperature of 180 to 220 ° C. can be used in the case of heat curing. On the other hand, in the case of ultraviolet curing, light having a wavelength of 200 to 430 nm, particularly 240 to 420 nm is generally used as the ultraviolet light including the near ultraviolet region. As the ultraviolet light source, a halide lamp, a high pressure mercury lamp, a low pressure mercury lamp, or the like is used. Since the thickness of the coating layer is small, it is an advantage that less energy is required for curing, generally 500 to 5000 joules / m 2.²Such energy is sufficient.
[0083]
[Printed packaging]
  The printed package of the present invention was applied to the outer surface of the package.Bright pigment (aluminum flake pigment)And a clear coating film provided on the printing ink layer. Bright pigments present in the printing ink layer(Aluminum flake pigment)Is the metallic reflected light with respect to the incident light, that is, the front reflected lightAnd giving the printing ink layer a lustrous appearance.
[0084]
In the printing package of the present invention, it is essential to have a clear coating film on the printing ink layer. That is, unlike the laminate of the film on which the ink layer is printed on the back, in the present invention, the printing ink layer is applied to the outer surface of the package by an offset method or the like. For this reason, it is essential to protect the outer surface of the printing ink layer with a clear coating film.
This clear coating not only mechanically protects the printing ink layer from scratching and peeling, but also has an auxiliary effect of improving the glitter by preventing irregular reflection from the outer surface of the printing ink layer. ing.
[0085]
The present invention provides the following three requirements in the printed package having the above-described configuration:
A. The average thickness of the printing ink layer is 0.2 to 10 μm, in particular 0.3 to 3 μm, most preferably 0.5 to 2 μm;
B. The average particle diameter (D) calculated from the area of the glitter pigment particles present in the printing ink layer is 3 to 20 μm, in particular 5 to 16 μm, and
C. The area ratio (S) occupied by the glitter pigment particles is 10% or more, particularly 20% or more,
Thus, it is possible to express bright, heavy and balanced glitter.
[0086]
First, in order to effectively exhibit the glitter, it is necessary for the printing ink layer to have a range of the glitter pigment particles having a certain thickness within a small and narrow range.
When the average film thickness of the printing ink layer is below the above-described range, the uneven transfer of the ink layer becomes remarkable, and the intended glossiness tends not to be obtained (Comparative Example 11). On the other hand, if this film thickness exceeds the above range, uniform application of the thermosetting clear coating film becomes difficult, or the adhesion of the ink layer becomes insufficient, the appearance becomes poor, and the glitter is also insufficient. (Comparative Example 12).
In the present invention, by setting the thickness of the printing ink layer to the above-mentioned relatively thin range, the orientation of the glitter pigment particles in the ink layer is set to the plane orientation or an orientation state close thereto, and bright glitter is printed. It can be applied to the ink layer.
[0087]
It is also important in terms of glitter that the average particle diameter (D) of the glitter pigment particles present in the printing ink layer is in the above range. In the present specification, unlike the median diameter (D50) referred to for ordinary powders, it is the average particle diameter (D) of particles actually measured from the area of the particles in the printing ink layer. It is measured by the method described in the examples.
When this average particle diameter (D) is less than the above range, the printing ink layer tends to be dark overall, and the glitter is insufficient (Comparative Example 1). On the other hand, when the average particle diameter (D) exceeds the above range, the difference in reflection between the portion having the glitter pigment and the portion without the glitter pigment is too large, and a balanced glitter cannot be obtained (Comparative Example 2).
[0088]
Furthermore, in the present invention, it is also important for the glitter to have the area ratio (S) occupied by the glitter pigment particles within the above range. This area ratio (S) is the ratio of the area occupied by the glittering pigment particles to the area of the printing ink layer, and can be specifically obtained by the method of Examples described later.
When this area ratio (S) is less than the above range, concealment by the glitter pigment becomes insufficient and the glitter is insufficient (Comparative Example 3).
In the present invention, the average particle diameter (D) of the glitter pigment particles is closely related to the microscopic reflection intensity (optical intensity of glitter) on the basis of one particle, while the area ratio (S) is closely related to the macroscopic reflection distribution of the printing ink layer as a whole, and because each of these is within the above range, bright, heavy and well-balanced glitter is achieved. To be expressed.
[0089]
Furthermore, regarding these combinations, the product of the square of the average particle diameter (D) and the area ratio (S) (D²XS) is preferably 300 or more, particularly 500 or more in terms of glitter.
When this product is less than the above range, a tendency that the glitter is reduced as compared with that in the above range is observed (Comparative Example 13).
The product of the square of the average particle diameter (D) and the area ratio (S) in the present invention (D²XS) is an amount of two significant figures for convenience.
[0090]
【Example】
  The present invention will be described in more detail based on the following examples.
  Of the following examples, Example 3 is a reference example outside the scope of the present invention.
[0091]
[Average particle diameter of glitter pigment in ink]
The printing ink in which the glitter pigment is dispersed is diluted with an appropriate solvent, and the average particle diameter is measured on a volume basis by a laser scattering method using this diluted solution (laser diffraction particle size distribution analyzer SALD-3000 (Shimadzu). Manufacturing))).
[Measurement of apparent viscosity of ink]
A rheometer for liquids ARES-100FRT-BATH-STD (Rheometric Scientific F.E. Co., Ltd.) was attached with a cone and plate type jig and the steady flow viscosity of the ink was measured at 35 ° C. Shear rate 100sec^-1Apparent viscosity η₁₀₀Got.
[Measurement of ink evaporation rate]
The ink was developed to have a thickness of 10 μm on one surface of a can lid aluminum plate having a thickness of 0.3 mm, a length of 20 cm, and a width of 5 cm measured in advance. The developed color plate was quickly weighed, then left in a room conditioned at 22 ° C. for 1 hour, and weighed again. During standing, the color plate was surrounded by a cardboard cover having a height of 30 cm so as not to be affected by the wind. The ink reduction rate when left in an open atmosphere was determined from the ink weight before and after being left. The reduction rate was calculated by 100 × (W1-W2) / W1, where W1 is the weight of the ink before being left and W2 is the weight of the ink after being left.
[0092]
[printing]
FIG. 4 shows an outline of the printing press. The ink placed in the ink pan was picked up by a sculpture roll having a grid-like sculpture, and transferred to a resin letterpress. The image on the resin relief printing was printed on a substrate via a blanket.
The engraving roll has a grid portion formed by parallel lines with a pitch of 120 lines / inch perpendicular to each other at 45 degrees and 135 degrees with respect to the roll axis. Inverted truncated pyramid-shaped holes with a depth of 30 μm with a side of a square of 110 μm (cell engraving roll with a cell volume of 18 cc), one side of the square of the opening of the hole is 170 μm, the bottom of the hole Inverted truncated pyramid shaped 20 μm deep holes with a square side of 110 μm (cell volume 12 cc engraving roll), square side of the opening of the hole is 160 μm, one side of the square serving as the bottom of the hole Inverted truncated pyramid shape with a depth of 110 μm and a hole with a depth of 15 μm (engraving roll with a cell volume of 8 cc), a depth of 160 μm in a lattice portion where the pitch of the parallel line group is 65 lines / inch A cross-sectional shape having an inverted truncated pyramid-shaped hole (a sculpture roll having a cell volume of 69 cc), and a parallel-line group pitch of 85 lines / inch in a lattice portion having a depth of 120 μm is an inverted truncated pyramidal shape. A hole provided with a hole (cell engraving roll with a cell volume of 58 cc), a hole with an inverted truncated pyramid shape having a cross-sectional shape of 14 μm in depth and a lattice portion having a pitch of 300 lines / inch of the parallel lines (cell) Engraving roll with a volume of 5 cc) or a structure in which a hole having an inverted truncated pyramid shape with a cross-sectional shape of 8 μm in depth is provided in a lattice portion where the pitch of the parallel line group line is 300 lines / inch (engraving roll with a cell volume of 3 cc) It was used.
As the blanket, an air blanket for metal printing having a cushion layer was used.
For the printing plate, a flexographic printing resin relief plate (Sirel EXL: DuPont Co., Ltd.) having a hardness of 70 degrees measured by the method described below, and a flexographic printing resin relief plate (Sirel NOW: DuPont (hardness) 78 degrees) are used. Co., Ltd.), a resin letterpress with a hardness of 90 degrees (B83S: Tokyo Ohka Kogyo Co., Ltd.), and a resin letterpress with a hardness of 97 degrees (WF95DII: Tokyo Ohka Kogyo Co., Ltd.).
[0093]
[Measurement of ink transfer weight]
The weight W3 [mg] of the uncured substrate immediately after printing, the weight W4 [mg] of the substrate before printing, and the printing screen area Acm²100 × (W3−W4) / A, print screen 100cm²The ink transfer weight of the hit was determined.
[Measurement of Covering Area Ratio (S)]
The produced package was cut into a flat plate shape, and an enlarged photograph of the glitter coating portion was taken with a reflection microscope. This photograph was subjected to image processing, and the coverage area ratio by the bright pigment portion was determined. In order to improve the reliability, the average value measured for a plurality of photographs was taken as S.
[0094]
[Measurement of average particle diameter (D) of glitter pigment]
Using the photograph used for the measurement of the covering area ratio, the covering area A of the bright pigment in the field of view was measured, and then the number n of the bright pigments in the field of view was measured.
Using this A and n, the following formula (3)
D = (A / n)^1/2      (3)
The particle size was calculated by the area method. In order to improve the reliability of the average particle diameter, the average value measured for a plurality of photographs was taken as D.
The average particle diameter (D) of the glitter pigment in the coating layer determined by the area method is an average particle diameter calculated based on the area of the glitter pigment visible when the coating layer is viewed from above. If the plane orientation is poor or overlapped, the value of D will be extremely different even if the same size of bright pigment is contained.
That is, when the orientation is good and the pigment is agglomerated as compared with the case where the pigment is scattered, D is the degree to which each of the glitter pigments contributes to the glitter feeling in the coating layer. It is a closely related quantity.
[Measurement of average film thickness of ink film after curing]
Using a contact-type surface roughness meter, the unevenness of the image area and the non-image area was measured for the cured printing can or printing plate, and the average film thickness was calculated from the measured value.
[Measurement of plate hardness]
The printing plate was placed on a flat test bench, and the hardness was measured using a jig for measuring JISA hardness. The reading of the hardness meter at this time was defined as JISA hardness.
[0095]
[Manufacture of thinned seamless cans]
Tin-free steel plate with a base plate thickness of 0.18 mm and a tempering degree of DR-9 (metal chromium content of 120 mg / m as surface treatment coverage)², Chromium oxide amount 15mg / m²A biaxially stretched polyethylene terephthalate / isophthalate copolymer film with a thickness of 20 μm on the side that becomes the inner surface of the can, and a biaxial surface with a thickness of 15 μm that contains 20% by weight of titanium oxide on the side that becomes the outer surface of the can. The stretched polyethylene terephthalate / isophthalate copolymer film was heat-bonded simultaneously on both sides at the melting point of the film, and immediately cooled with water to obtain an organic coated metal plate. A glamor wax was uniformly applied to the organic coated metal plate, and then punched out into a disk having a diameter of 160 mm to form a shallow drawn cup according to a conventional method. The drawing ratio in this drawing step is 1.59.
Next, primary and secondary redrawing processes were performed by bending and stretching to obtain a thinned deep drawn recup. The molding conditions of the redrawing process and various characteristics of the deep drawn cup after redrawing are shown below.
Primary redrawing ratio 1.23
Secondary redrawing ratio 1.24
Redrawing die action corner radius of curvature 0.30mm
Redrawing die holding corner radius of curvature 1.0mm
Cup diameter 66mm
Cup height 130mm
Side wall thickness change rate -40%
Then, after performing doming molding according to a conventional method, the deep drawn cup was heat-treated at 215 ° C. for 1 minute to remove film processing distortion and volatilize the lubricant. Next, the edge of the opening end was cut off to obtain a resin-coated thinned seamless can having a height of 123 mm.
[0096]
[Example 1]
200 parts by weight of a liquid polyester resin (NS2400: Asahi Denka Kogyo Co., Ltd.) was placed in a stainless steel cup, and 115 parts by weight of diethylene glycol butyl ether acetate was added with stirring. Next, 100 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 1.5 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) were added with stirring, and then a non-particle having an average particle diameter of 13 μm. A glittering ink was obtained by adding 95 parts by weight of a leafing type aluminum paste with stirring and sufficiently dispersing aluminum particles. The content of the glitter pigment in the glitter ink is 13% by weight, η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the prepared ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 24mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printing portion with the glitter pigment is 28%, the average particle diameter (D) is 8.0 μm, and D²XS was 1800. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0097]
[Example 2]
In a stainless steel cup, 250 parts by weight of a liquid polyester resin (NS2400: Asahi Denka Kogyo Co., Ltd.) was added, and 150 parts by weight of diethylene glycol butyl ether acetate was added while stirring. Subsequently, 150 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 2.0 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) were added with stirring, and then leafing with an average particle size of 8 μm was performed. A bright ink was obtained by adding 70 parts by weight of a type of aluminum paste with stirring and sufficiently dispersing the aluminum particles. The content of the glitter pigment in the glitter ink is 7% by weight, and η at 35 ° C.₁₀₀Was 0.19 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 3%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the prepared ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 22mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 39% and the average particle diameter (D) is 4.1 μm.²XS was 660. The average film thickness of the ink film after drying was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0098]
[Example 3](Reference example)
  200 parts by weight of a liquid polyester resin (NS2400: Asahi Denka Kogyo Co., Ltd.) was placed in a stainless steel cup, and 115 parts by weight of diethylene glycol butyl ether acetate was added with stirring. Next, 100 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 1.5 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) were added with stirring, and then oxidized with an average particle size of 16 μm. A glittering ink was obtained by adding 110 parts by weight of titanium-coated mica with stirring and sufficiently dispersing the mica particles. The content of the glitter pigment in the glitter ink is 21% by weight, and η at 35 ° C.₁₀₀Was 0.24 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 1%.
  Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the prepared ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 25mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 44% and the average particle diameter (D) is 9.1 μm.²XS was 3600. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0099]
[Example 4]
189 parts by weight of a liquid polyester resin (NS2400: Asahi Denka Kogyo Co., Ltd.) was placed in a stainless steel cup, and 108 parts by weight of diethylene glycol butyl ether acetate was added while stirring. Next, 94 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 2.5 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) were added with stirring, and the average particle size was 0.04 μm. 26 parts by weight of silica powder (AEROSIL OX50: Nippon Aerosil Co., Ltd.) was added and vigorously stirred and dispersed for 10 minutes at a stirring speed of 1000 rpm using a homogenizer (Special Machine Industries Co., Ltd.). Next, this transparent fine particle-containing resin solution was kneaded with a three-roll mill to sufficiently disperse the silica powder. A bright ink is obtained by adding 80 parts by weight of non-leafing type aluminum paste with an average particle size of 13 μm to 340 parts by weight of the transparent fine particle-containing resin solution after the three-roll mill treatment, and sufficiently dispersing the aluminum particles. It was. The glitter ink has an aluminum content of 13% by weight and a silica powder content of 5% by weight.₁₀₀Was 0.25 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the prepared ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 33mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 43% and the average particle diameter (D) is 8.4 μm.²XS was 3000. The average film thickness of the ink film after drying was 1.6 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0100]
[Example 5]
The ink of Example 4 was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 8 cc and a printing plate having a hardness of 70 degrees. Ink transfer weight is 23mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 33% and the average particle diameter (D) is 8.5 μm.²XS was 2400. The amount of ink on the can was almost the same as in Example 1, but the addition of transparent fine particles improved the area coverage of the glitter pigment and the orientation of the glitter pigment as compared to Example 1. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0101]
[Example 6]
A glittering ink was prepared in the same manner as in Example 4 except that silica powder having an average particle size of 0.3 μm (Seahoster KE-E30: Nippon Shokubai Co., Ltd.) was used. The glitter pigment content in the glitter ink is 13% by weight, the silica powder content is 5% by weight, and η at 35 ° C.₁₀₀Was 0.23 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 22mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. Covering area ratio (S) by glitter pigment is 31% and average particle diameter (D) is 8.4 μm. Transferability of ink, covering area ratio (S) by glitter pigment in glitter printing portion and average grain The diameter (D) was almost the same as in Example 5. In this case, D²XS was 2200. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0102]
[Example 7]
A glittering ink was prepared in the same manner as in Example 6 except that the silica powder was 130 parts by weight. The glitter pigment content in the glitter ink is 13% by weight, the silica powder content is 20% by weight, and η at 35 ° C.₁₀₀Was 0.53 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 23mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. Covering area ratio (S) by glitter pigment is 32% and average particle diameter (D) is 8.4 μm. Transferability of ink, covering area ratio (S) by glitter pigment in average printing area and average grain The diameter (D) was almost the same as in Example 5. In this case, D²XS was 2300. The average film thickness of the ink film after drying was 1.1 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0103]
[Example 8]
A glittering ink was prepared in the same manner as in Example 4 except that the silica powder was adjusted to 2.5 parts by weight. The glitter pigment content in the glitter ink is 13% by weight, the silica powder content is 0.5% by weight, and η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 21mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. Covering area ratio (S) with glitter pigment is 31% and average particle diameter (D) is 8.3 μm. Transferability of ink, covering area ratio (S) with glitter pigment in glitter printing portion and average grain The diameter (D) was almost the same as in Example 5. In this case, D²XS was 2100. The average film thickness of the ink film after drying was 1.1 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0104]
[Example 9]
A glittering ink was prepared in the same manner as in Example 4 except that silica powder having an average particle size of 1 μm (Seahoster KE-E90: Nippon Shokubai Co., Ltd.) was used and kneading with a three-roll mill was not performed. The glitter pigment content in the glitter ink is 13% by weight, the silica powder content is 5% by weight, η100 at 35 ° C. is 0.22 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. Was 6%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 22mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. Covering area ratio (S) with glitter pigment is 30% and average particle diameter (D) is 8.3 μm. Transferability of ink, covering area ratio (S) with glitter pigment in glitter printing portion and average grain The diameter (D) was almost the same as in Example 5. In this case, D²XS was 2100. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0105]
[Example 10]
A glittering ink was prepared in the same manner as in Example 4 except that 2.5 parts by weight of silica powder having an average particle size of 0.01 μm (R974: Nippon Aerosil Co., Ltd.) was used. The glitter pigment content in the glitter ink is 13% by weight, the silica powder content is 0.5% by weight, η100 at 35 ° C. is 0.21 Pa · sec, and the weight when left in an open atmosphere at 22 ° C. The reduction rate was 6%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 21mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. Covering area ratio (S) by glitter pigment is 31% and average particle diameter (D) is 8.4 μm. Transferability of ink, covering area ratio (S) by glitter pigment in glitter printing portion and average grain The diameter (D) was almost the same as in Example 5. In this case, D²XS was 2200. The average film thickness of the ink film after drying was 1.1 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0106]
[Example 11]
A glittering ink was prepared in the same manner as in Example 2 except that 47 parts by weight of a leafing type aluminum paste having an average particle diameter of 5 μm was used. The content of the glitter pigment in the glitter ink is 5% by weight, and η at 35 ° C.₁₀₀Was 0.19 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 2%.
Using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 90 degrees, the adjusted ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 13mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) with the glitter pigment is 34% and the average particle diameter (D) is 3.0 μm.²XS was 300. The average film thickness of the ink film after drying was 0.7 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0107]
[Example 12]
An ink was prepared in the same manner as in Example 1 except that 550 parts by weight of a non-leafing type aluminum paste having an average particle size of 15 μm was used. The content of the glitter pigment in the glitter ink is 40% by weight, η at 35 ° C.₁₀₀Was 0.63 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 18%.
Using a printing machine equipped with a 12cc cell engraving roll and a 70 degree hardness printing plate, the adjusted ink was printed on a thin-walled seamless can. The ink showed good transferability and the glitter of the printed material It was excellent. Ink transfer weight is 26mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) with the glitter pigment is 57% and the average particle diameter (D) is 9.6 μm.²XS was 5300. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0108]
[Example 13]
An ink was prepared in the same manner as in Example 1 except that 70 parts by weight of a non-leafing type aluminum paste having an average particle size of 25 μm was used. The content of the glitter pigment in the glitter ink is 10% by weight, η at 35 ° C.₁₀₀Was 0.19 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 4%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability and the glitter of the printed matter It was excellent. Ink transfer weight is 15mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) with the glitter pigment is 10% and the average particle diameter (D) is 20 μm.²XS was 4000. The average film thickness of the ink film after drying was 0.8 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0109]
[Example 14]
A glittering ink was prepared in the same manner as in Example 1 except that 70 parts by weight of non-leafing type aluminum paste having an average particle size of 15 μm and 25 parts by weight of non-leafing type aluminum paste having an average particle size of 8 μm were used. The content of the glitter pigment in the glitter ink is 13% by weight, η at 35 ° C.₁₀₀Was 0.21 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the prepared ink was printed on a thin-walled seamless can. It was excellent. Ink transfer weight is 24mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 37% and the average particle diameter (D) is 5.9 μm.²XS was 1300. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0110]
[Example 15]
In a four-necked flask equipped with a stirring blade, thermometer, and condenser, 130 parts by weight of a solid polyester resin (Byron 220: Toyobo Co., Ltd.), 130 parts by weight of toluene, and 80 parts by weight of diethylene glycol butyl ether acetate are stirred. While heating to 110 ° C., the polyester resin was dissolved. After cooling this solution to 40 ° C. or less, 100 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 1.3 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) are added with stirring. A resin solution was obtained. To this resin solution, 95 parts by weight of non-leafing type aluminum paste having an average particle size of 13 μm was added with stirring, and the aluminum particles were sufficiently dispersed to obtain a glittering ink. The content of the glitter pigment in the glitter ink is 13% by weight, and η at 35 ° C.₁₀₀Was 0.063 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 30%.
Using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the adjusted ink was printed on a sheet for a 200 ml welded can provided with a white coat layer on the printing surface. In addition, the printed material was excellent in glitter. Ink transfer weight is 14mg / 100cm²Met. The printing plate was heat-treated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glittering printed portion with the glitter pigment is 18% and the average particle diameter (D) is 8.2 μm.²XS was 1200. The average film thickness of the ink film after drying was 0.5 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0111]
[Example 16]
A glittering ink was prepared in the same manner as in Example 15 except that a leafing type aluminum paste having an average particle diameter of 8 μm was used. The content of the glitter pigment in the glitter ink is 13% by weight, and η at 35 ° C.₁₀₀Was 0.068 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 30%.
When the adjusted ink equipped with an engraving roll having a cell volume of 5 cc and a printing plate having a hardness of 70 degrees was printed on a sheet for a 200 ml welded can provided with a white coat layer on the printing surface side, the ink showed good transferability, The glitter of the printed material was also excellent. Ink transfer weight is 5mg / 100cm²Met. The printing plate was heat-treated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printing portion with the glitter pigment is 27%, the average particle diameter (D) is 4.3 μm, and D²XS was 500. The average film thickness of the ink film after drying was 0.2 μm. When the finished varnish was painted and dried on this printing can according to a conventional method, it had an excellent appearance with a good glitter.
[0112]
[Example 17]
A four-necked flask equipped with a stirring blade, thermometer, and cooling tube, 300 parts by weight of an alicyclic epoxy resin (UVR6110: Union Carbide Japan Co., Ltd.), and 50% by weight of polyester resin (Byron GK810: Toyobo Co., Ltd.) And 50 parts by weight of oxetane alcohol (OXT-1: Toagosei Chemical Industry Co., Ltd.) were added and heated to 110 ° C. with stirring to completely dissolve the polyester resin. After cooling this solution to 40 ° C., 20 parts by weight of a photoinitiator (UVI-6990: Union Carbide Japan Co., Ltd.) and 95 parts by weight of non-leafing type aluminum paste having an average particle size of 13 μm were added with stirring. A glittering ink was obtained by sufficiently dispersing the particles. The content of the glitter pigment in the glitter ink is 13% by weight, η at 35 ° C.₁₀₀Was 2.0 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 5%.
Using a printing machine equipped with an engraving roll with a cell volume of 18 cc and a printing plate with a hardness of 78 degrees, the adjusted ink was printed on a sheet for a 200 ml welded can provided with a white coat layer on the printing surface. In addition, the printed material was excellent in glitter. Ink transfer weight is 40mg / 100cm²Met. 1000 J / m using a metal halide lamp on this printing plate²The ultraviolet rays were irradiated to cure the ink. The coverage area ratio (S) of the glittering printed portion with the glittering pigment was 51%, and the average particle diameter (D) was 8.0 μm. D²XS was 3300. The average film thickness of the ink film after curing was 3.1 μm. When the finished varnish was painted and dried on this printing plate according to a conventional method, it had an excellent appearance with a good glitter.
[0113]
[Example 18]
The ink of Example 17 was printed on a sheet for a 200 ml welded can provided with a white coat layer on the printing surface side using a printing machine equipped with an engraving roll having a cell volume of 58 cc and a printing plate having a hardness of 78 degrees. Exhibited good transferability, and the gloss of the printed material was also excellent. Ink transfer weight is 110mg / 100cm²Met. 1000 J / m using a metal halide lamp on this printing plate²The ultraviolet rays were irradiated to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 71%, the average particle diameter (D) is 7.0 μm, and D²XS was 3500. The average film thickness of the cured ink film was 10 μm. When the finished varnish was painted and dried on this printing plate according to a conventional method, it had an excellent appearance with a good glitter.
[0114]
[Comparative Example 1]
A glittering ink was prepared in the same manner as in Example 2 except that a leafing type aluminum paste having an average particle diameter of 4 μm was used. The content of the glitter pigment in the glitter ink is 7% by weight, and η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 5%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 8 cc and a printing plate having a hardness of 70 degrees, the printed matter was dark and the desired glitter was not obtained. Ink transfer weight is 15mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printing portion with the glitter pigment is 59% and the average particle diameter (D) is 1.9 μm.²XS was 210. The average film thickness of the ink film after drying was 0.8 μm. A finish varnish was applied to this printing plate and dried according to a conventional method, but the glossiness was improved but the glitter was not improved.
[0115]
[Comparative Example 2]
A glittering ink was prepared in the same manner as in Example 1 except that a non-leafing type aluminum paste having an average particle size of 30 μm was used. The content of the glitter pigment in the glitter ink is 13% by weight, η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the adjusted ink was printed on a thin-walled seamless can, but the glitter pigment particles were too large although they were glittering. For this reason, the difference between the portion with and without the pigment was too large, and a well-balanced glitter feeling could not be obtained. Ink transfer weight is 23mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 15% and the average particle diameter (D) is 22 μm.²XS was 7300. The average film thickness of the dried ink film was 1.2 μm. A finish varnish was applied to this printing plate and dried according to a conventional method, but the glossiness was improved but the glitter was not improved.
[0116]
[Comparative Example 3]
A glittering ink was prepared in the same manner as in Example 1 except that the blending amount of the aluminum paste was 25 parts by weight. The content of the glitter pigment in the glitter ink is 4% by weight, and η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 2%.
Using a printing machine equipped with an engraving roll with a cell volume of 12 cc and a printing plate with a hardness of 70 degrees, the adjusted ink was printed on a thin-walled seamless can. As a result, there were too few glitter pigment particles and no glitter was obtained. It was. Ink transfer weight is 22mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glittering printed portion with the glittering pigment is 8% and the average particle diameter (D) is 8.9 μm.²XS was 630. The average film thickness of the dried ink film was 1.2 μm. A finish varnish was applied to this printing plate and dried according to a conventional method, but the glossiness was improved but the glitter was not improved.
[0117]
[Comparative Example 4]
A glittering ink was prepared in the same manner as in Example 1 except that the blending amount of the aluminum paste was 650 parts by weight. The content of the glitter pigment in the glitter ink is 43% by weight, and η at 35 ° C.₁₀₀Was 1.1 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 19%.
Using a printing machine equipped with an engraving roll having a cell volume of 12 cc and a printing plate having a hardness of 70 degrees, the adjusted ink was printed on a thinned seamless can. Printing was difficult.
[0118]
[Comparative Example 5]
In a four-necked flask equipped with a stirring blade, thermometer, and condenser, 200 parts by weight of solid polyester resin (Byron 220: Toyobo Co., Ltd.) and 115 parts by weight of diethylene glycol butyl ether acetate are heated to 110 ° C. while stirring. The polyester resin was dissolved. After cooling this solution to 40 ° C. or less, 100 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 2.5 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) are added with stirring. It was. Next, 100 parts by weight of a non-leafing type aluminum paste having an average particle size of 13 μm was added with stirring, and the aluminum particles were sufficiently dispersed to obtain a glittering ink. The content of the glitter pigment in the glitter ink is 13% by weight, η at 35 ° C.₁₀₀Was 2.4 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 5%.
When the adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 12 cc and a printing plate having a hardness of 70 degrees, the printed matter was excellent in glitter, but the η at 35 ° C.₁₀₀Is larger than the range of the present invention, the ink tends to accumulate on the printing plate, resulting in a printed matter with remarkably poor reproducibility of the overall thickness.
[0119]
[Comparative Example 6]
In a four-necked flask equipped with a stirring blade, thermometer, and cooling tube, 130 parts by weight of a solid polyester resin (Byron 220: Toyobo Co., Ltd.), 160 parts by weight of toluene, and 50 parts by weight of diethylene glycol butyl ether acetate are added and stirred. While heating to 110 ° C., the polyester resin was dissolved. After cooling this solution to 40 ° C. or less, 100 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 1.3 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) are added with stirring. A resin solution was obtained. To this resin solution, 95 parts by weight of non-leafing type aluminum paste having an average particle size of 13 μm was added with stirring, and the aluminum particles were sufficiently dispersed to obtain a glittering ink. The content of the glitter pigment in the glitter ink is 13% by weight, and η at 35 ° C.₁₀₀0.053 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 35%.
Using a printing machine equipped with an engraving roll with a cell volume of 8 cc and a printing plate with a hardness of 70 degrees, the adjusted ink was printed on a thin-walled seamless can. The ink on the plate and blanket tended to dry during printing. The amount of ink deposited on the plate and blanket and transferred to the can was extremely small.
[0120]
[Comparative Example 7]
A glittering ink was prepared in the same manner as in Example 4 except that silica powder having an average particle size of 4 μm (Pyrospher C-1504: Fuji Silysia Chemical Co., Ltd.) was used and kneading with a three-roll mill was not performed. Adjusted. In the resulting glittering ink, the content of the glittering pigment was 13% by weight, the content of the silica powder was 5% by weight, and η at 35 ° C.₁₀₀Was 0.36 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
The prepared ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 12 cc and a printing plate having a hardness of 70 degrees. Since the silica powder has a large average particle size of 4 μm, the silica powder tends to be left in the blanket, and the transition weight is 22 mg / 100 cm.²Thus, the effect of adding transparent fine particles was not recognized. In addition, the cured printing can had a rough ink film and a poor appearance, but the glittering glitter was good. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 24% and the average particle diameter (D) is 8.3 μm.²XS was 1700. The average film thickness of the dried ink film was 1.2 μm. The finished varnish was applied to this printing plate and dried according to a conventional method, but the gloss was improved, but the appearance of the rough print was not changed.
[0121]
[Comparative Example 8]
A glittering ink was prepared in the same manner as in Example 4 except that the silica powder was 2 parts by weight. The glittering pigment content in the resulting glittering ink was 13% by weight, the silica powder content was 0.4% by weight, and η at 35 ° C.₁₀₀Was 0.20 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 6%.
The prepared ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 12 cc and a printing plate having a hardness of 70 degrees. Ink transfer weight is 24mg / cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 29%, the average particle diameter (D) is 8.1 μm, and D²XS was 1900. In this case, since the concentration of the silica powder was smaller than the range of the present invention, the effect of adding transparent fine particles was not recognized. The glitter was good. The average film thickness of the dried ink film was 1.2 μm. When the finished varnish was painted and dried on this printing plate according to a conventional method, it had an excellent appearance with a good glitter.
[0122]
[Comparative Example 9]
A glittering ink was prepared in the same manner as in Example 6 except that the silica powder was 150 parts by weight. The glittering pigment content in the resulting glittering ink was 13% by weight, the silica powder content was 22% by weight, and η at 35 ° C.₁₀₀Was 0.61 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 5%.
The adjusted ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll having a cell volume of 8 cc and a printing plate having a hardness of 70 degrees. Ink transfer weight is 25mg / cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion of the glitter printed portion is 32% and the average particle diameter (D) is 8.4 μm.²XS was 2300. Although the glitter was good, the glitter pigment surface was slightly inferior to Example 7 because the surface of the glitter pigment was excessively covered with silica fine particles.
The average film thickness of the ink film after drying was 1.1 μm. When the finished varnish was painted and dried on this printing plate according to a conventional method, it had an excellent appearance with a good glitter.
[0123]
[Comparative Example 10]
Printing was performed in the same manner as in Example 1 except that a printing plate having a hardness of 97 degrees was used. In this case, the glittering pigment is deposited on the printing plate, and only a part of the fine glittering pigment is transferred to the can, and it is difficult to continue printing.
[0124]
[Comparative Example 11]
Printing was performed in the same manner as in Example 17 except that an engraving roll having a cell volume of 3 cc was used. In this case, the transfer was greatly uneven and the appearance was poor. Also, there was no glitter. 1000 J / m using a metal halide lamp on this printing plate²The ultraviolet ray was irradiated to cure the ink, and the average film thickness of the cured ink at this time was 0.1 μm. As described above, when the average film thickness of the ink film is smaller than the range of the present invention, the transfer unevenness becomes remarkable, and a printed matter having a good appearance cannot be obtained.
[0125]
[Comparative Example 12]
Printing was performed in the same manner as in Example 17 except that an engraving roll having a cell volume of 69 cc was used. Ink transfer weight is 150mg / 100cm²Met. In this case, the glittering feeling was good, but the image reproduction was extremely bad because it was too thick. 1000 J / m using a metal halide lamp on this printing plate²The ultraviolet rays were irradiated to cure the ink. The coverage area ratio (S) of the glittering printed portion with the glittering pigment was 78%, and the average particle diameter (D) was 7.0 μm. D²XS was 3800. The average film thickness of the cured ink film was 12 μm. When the finished varnish was painted and dried on this printing plate according to a conventional method, the level difference between the image area and the non-image area was conspicuous, and in addition to the poor image reproduction, the printed material had a remarkably poor appearance.
[0126]
[Comparative Example 13]
In a stainless steel cup, 250 parts by weight of a liquid polyester resin (NS2400: Asahi Denka Kogyo Co., Ltd.) was added, and 150 parts by weight of diethylene glycol butyl ether acetate was added while stirring. Subsequently, 150 parts by weight of an amino resin (Cymel 235: Mitsui Cytec Co., Ltd.) and 2.0 parts by weight of an acid catalyst (Catalyst 600: Mitsui Cytec Co., Ltd.) were added with stirring, and then a non-particle having an average particle diameter of 8 μm. A glittering ink was obtained by adding 45 parts by weight of a leafing type aluminum paste with stirring and sufficiently dispersing aluminum particles. The content of the glitter pigment in the glitter ink is 5% by weight, and η at 35 ° C.₁₀₀Was 0.19 Pa · sec, and the weight reduction rate when left in an open atmosphere at 22 ° C. was 2%.
When the prepared ink was printed on a thin-walled seamless can using a printing machine equipped with an engraving roll with a cell volume of 5 cc and a printing plate with a hardness of 70 degrees, the ink showed good transferability, but the printed material had a glittery feeling. And lack of concealment. Ink transfer weight is 9mg / 100cm²Met. The printing can was heated at 205 ° C. for 2 minutes to cure the ink. The coverage area ratio (S) of the glitter printed portion with the glitter pigment is 15% and the average particle diameter (D) is 4.3 μm.²XS was 280. The average film thickness of the ink film after drying was 0.5 μm. The finished varnish was painted and dried on this printing can according to a conventional method, but the gloss was improved, but the poor glitter was not improved.
[0127]
About the above result, an ink characteristic is shown to Table 1, Table 2, and a printing result is shown to Table 3, Table 4. FIG.
[0128]
[Table 1]

[0129]
[Table 2]

[0130]
[Table 3]

[0131]
[Table 4]

[0132]
【The invention's effect】
  According to the present invention,As a bright pigment, an aluminum flake pigment having an average particle diameter (measured by a laser scattering method) of 5 to 25 μm, particularly 5 to 20 μm, is contained in an amount of 5 to 40% by weight,Shear rate 100 sec at 35 ° C^-1Apparent viscosity η₁₀₀By providing a printing ink layer of 2 Pa · sec or less, the formed printing ink layer is excellent in glitter, and also has excellent ink transferability and can provide a printing ink capable of reproducible printing. it can.
  According to the present invention, the printing ink is transferred to the blanket using a printing plate having a JIS A hardness of 90 degrees or less, and the printing ink on the blanket is used. Printing method capable of forming a printed image with excellent glitter and excellent print reproducibility on a printing medium such as a sheet or a metal can by transferring it to the printing mediumIs provided.
  According to the invention,By providing a printing ink layer containing an aluminum flake pigment by printing using the ink described above,A clear coating film is provided on the printing ink layer, and the average film thickness of the printing ink layer is 0.2 to 10 μm, particularly 0.3 to 3 μm, most preferably 0.5 to 2 μm. Bright pigment particles present in the ink layer(Aluminum flake pigment)By making the average particle diameter (D) calculated from the area of 3 to 20 μm and the area ratio (S) occupied by the glitter pigment particles to be 10% or more, it has a bright and heavy glitter, A printed package having useful decorative properties and excellent commercial value can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a cross-sectional structure of a conventional print package (can).
FIG. 2 is a cross-sectional view showing an example of a cross-sectional structure of a can used in the present invention.
FIG. 3 is a cross-sectional view showing another example of the cross-sectional structure of the can used in the present invention.
FIG. 4 is a side view showing a schematic arrangement of a printing machine used for manufacturing a printed package of the present invention.
FIG. 5 is a side view showing a schematic arrangement of another printing machine used for manufacturing the printed package of the present invention.

Claims (9)

An aluminum flake pigment having an average particle diameter (measured by a laser scattering method) of 5 to 25 μm is contained in an amount of 5 to 40% by weight, and an apparent viscosity η _{100 at a} shear rate of 100 sec ^{−1 at} 35 ° C. is 2 Pa · sec or less. Printing ink characterized by being.   2. The printing ink according to claim 1, wherein a weight reduction rate when left in an open atmosphere at 22 ° C. for 1 hour is 30% or less.   The printing ink according to claim 1 or 2, comprising 0.5 to 20% by weight of transparent fine particles having an average particle diameter of 0.01 to 1 µm. In a printing method comprising transferring printing ink on a printing plate to a blanket and transferring the printing ink on the blanket to a substrate, the printing ink has an average particle diameter of 5 to 25 μm (measured by laser scattering method). The aluminum flake pigment is contained in an amount of 5 to 40% by weight, the apparent viscosity η _{100 at a} shear rate of 100 sec ^{−1 at} 35 ° C. is 2 Pa · sec or less, and the printing plate is JIS
A printing method having A hardness of 90 degrees or less. A printing ink layer is provided by printing using the printing ink according to any one of claims 1 to 3 , and a clear coating film is provided on the printing ink layer. The average particle diameter (D) calculated from the area of the aluminum flake pigment particles existing in the printing ink layer is 0.2 to 10 μm, and the area ratio (S) occupied by the aluminum flake pigment particles is 3 to 20 μm. A printed package excellent in glitter, characterized by being 10% or more. The average particle diameter (D) and area ratio (S) are expressed by the formula D ^2. The printed metal package according to claim 5, wherein the printed metal package has a relationship satisfying × S ≧ 300.   The printing package according to claim 5 or 6, wherein transparent fine particles are contained in the printing ink layer.   The printed metal package according to any one of claims 5 to 7, wherein the package is a container or a container lid.   The printed packaging body according to any one of claims 5 to 8, wherein the printing ink layer is applied to the outer surface of the packaging body by an offset method.

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