JP3952263B2

JP3952263B2 - High light-shielding paper

Info

Publication number: JP3952263B2
Application number: JP2001353739A
Authority: JP
Inventors: 敬一小貫; 格阿部; 剛米山; 義之水口
Original assignee: Toppan Inc; Hokuetsu Package Co Ltd
Current assignee: Toppan Inc; Hokuetsu Package Co Ltd
Priority date: 2001-11-19
Filing date: 2001-11-19
Publication date: 2007-08-01
Anticipated expiration: 2021-11-19
Also published as: JP2003155698A

Description

【０００１】
【発明の属する技術分野】
本発明はスピードくじやトランプ等のカードあるいは個人情報を記録した用紙、その他各種用途の用紙であって、表面に印刷、記録した文字、数字、記号等が裏面からの強光源によって判読不能で、かつリサイクル可能で焼却時の焼却残滓の少ない高遮光性用紙に関する。
【０００２】
【従来の技術】
スピードくじは同じ等級が３個出れば当たりで、その等級に応じて当選金が受け取れるくじである。表面に印刷してある数字はアルミ粉等を配合したペーストで隠ぺいされており、購入時にその隠ぺいされている箇所を硬貨などでけずって３個の数字を確認する訳であるが、硬貨などでけずる前に裏面から強い光源を当ててもその数字が読取れないようにすることが重要である。
【０００３】
従来のこの種のスピードくじは、紙の中間にアルミ箔を介在させて裏面から強い光源を当ててもその数字が読取れないようにしていた。
また、アルミニウム粉末を含有する隠ぺい層を設けない原紙とアルミニウム粉末を含有する隠ぺい層を設けた原紙を、隠ぺい層が両者の中間になるように水性アクリル樹脂系糊を用いて貼り合わせたものがある。あるいは強光源の光を乱反射、散乱等をさせる隠ぺい層を設けた原紙と、該隠ぺい層を設けない原紙とを接着剤を介して貼り合わせたものがある。さらに、光を吸収する黒紙を原紙の間に介在させて貼り合わせたものや、原紙と原紙をカーボンブラック等を分散せしめた接着剤で貼り合わせたものがある。
【０００４】
【発明が解決しようとする課題】
しかし、紙の中間にアルミ箔(Al箔)を介在させたものにあっては、表面に印刷した数字等が裏面から強光源を当てても判読できないという強い隠ぺい力を有しているが、使用後のリサイクルが困難であったり、焼却処分時に燃えるゴミとして扱えないなどの難点があった。またアルミニウム粉末を含有する隠ぺい層を設けた原紙を使用した場合にも焼却処分時に燃えるゴミとして扱えないなどの難点があった。さらに、強光源の光を乱反射、散乱等をさせる隠ぺい層を設けた原紙と、該隠ぺい層を設けない原紙とを接着剤を介して貼り合わせたものにあって、隠ぺい層を厚く形成しなければならず、薄さを要求される用途には適しないものであった。加えて、黒紙は抄紙する際にカーボンブラックがパルプに定着しずらいという歩留の悪さや、分散不良による均一なる隠ぺい性に劣るという問題があった。また、黒色系接着剤とするために接着剤に起因する粘性の高さによるカーボンブラックの分散不良に伴なう隠ぺい性の不均一性や、カーボンブラック比率の高いことに起因する接着力不足の問題があった。
【０００５】
本発明は上記の点に鑑みてなされたもので、その目的とするところは、強光源の光を吸収し、該光を遮る高遮光層を薄く形成するとともに再生紙としてリサイクルが可能で、燃えるごみとして焼却でき、焼却残滓の少ない高遮光性用紙を提供することにある。
【０００６】
【課題を解決するための手段】
本発明に係る高遮光性用紙は、表紙は廃棄焼却時に有害ガスが発生しないカオリン、炭酸カルシウム等の無機顔料の塗工顔料を用いた両面コートのＡ２コート紙で、裏紙は廃棄焼却時に有害ガスが発生しないカオリン、炭酸カルシウム等の無機顔料の塗工顔料を用いた両面コートのＡ２マットコート紙でそれぞれ形成し、前記表紙の裏面の全面に強光源からの光を遮る黒色系塗料からなる複数層の高遮光層を重ね塗りにより形成するか、又は前記裏紙の裏面の全面に強光源からの光を遮る黒色系塗料からなる複数層の高遮光層を重ね塗りにより形成し、該高遮光層の上にＳＢＲ系接着剤、アクリル樹脂系接着剤等の廃棄焼却時に有害ガスが発生しない接着剤を介して上記裏紙の裏面の全面又は上記表紙の裏面の全面を接着するとともに上記黒色系塗料はウエットの状態で合計塗工量が２０〜３０ｇ／ｍ ² であり、かつ該黒色系塗料の固形分濃度が１ｇ中に３０〜５０％であることを特徴とする。
【０００７】
また本発明に係る高遮光性用紙は、表紙は廃棄焼却時に有害ガスが発生しないカオリン、炭酸カルシウム等の無機顔料の塗工顔料を用いた両面コートのＡ２コート紙で、裏紙は廃棄焼却時に有害ガスが発生しないカオリン、炭酸カルシウム等の無機顔料の塗工顔料を用いた両面コートのＡ２マットコート紙でそれぞれ形成し、前記表紙の裏面の全面及び前記裏紙の裏面の全面に強光源からの光を遮る黒色系塗料からなる高遮光層をそれぞれ形成し、前記高遮光層同士を対向させ、該対向する高遮光層間にＳＢＲ系接着剤、アクリル樹脂系接着剤等の廃棄焼却時に有害ガスが発生しない接着剤を介して接着し、上記黒色系塗料はウエットの状態で合計塗工量が２０〜３０ｇ／ｍ ² であり、かつ該黒色系塗料の固形分濃度が１ｇ中に３０〜５０％であることを特徴とする。
【００１１】
【発明の実施の形態】
本発明で使用する塗工紙はアート紙、上質コート紙、中質コート紙、軽量コート紙、微塗工紙、キャストコート紙、エンボス紙、その他塗工紙があるが、両面塗工及び片面塗工のいずれであっても良いが、片面塗工の場合はカールが発生し易いので裏面にカール防止加工等を施すのが好ましい。また高遮光層及び接着剤を介在させて表裏面を塗工紙を用いて接着したときに裏面側を非塗工面にしたときにはペン書きなどの筆記性が良好となる。塗工紙用塗料（コーティングカラー）としてはカオリン（クレー）、炭酸カルシウム、サチンホワイト、二酸化チタン、水酸化アルミニウム等の無機顔料を使用する。プラスチックポリマーをベースとした有機顔料は廃棄焼却処分時に有害ガス等を生じないものであれば良い。
塗工紙の塗工面は多色印刷等の印刷適性が良好である。
【００１２】
本発明で原則として塗工紙を採用し、非塗工紙を採用しない理由は後述する高遮光層中の黒色系塗料や強光源からの光を吸収する黒色系顔料を含有する接着剤中の黒色系顔料が原紙側ににじみ等により前記塗料や顔料が移行することにより強光源からの光の吸収性や白色度等がそれぞれ低下しないようにするためである。したがって、片面塗工紙の場合は塗工面側に強光源からの光を遮る黒色系塗料からなる高遮光層や黒色系顔料を含有する接着剤を形成する必要がある。
しかし、塗工紙同士の貼り合わせを原則とするが、裏紙に相当する紙として非塗工紙を採用してもよい。該非塗工紙側に黒色系塗料や黒色系顔料を有する接着剤を塗工しない配慮が必要である。非塗工紙はペン書き等の筆記特性が塗工紙に比べ一層の向上が期待出来る。
【００１３】
本発明で使用する強光源からの光を遮る黒色系塗料からなる高遮光層塗料はいわゆる黒コートと称するもので、例えばカーボンブラック等の黒色系塗料が採用される。黒色系塗料の塗工量はウエットの状態で１回当り１０〜３０ｇ／ｍ^２で例えばグラビア塗工その他の手段により１回又は複数回の重ね塗りを行なう。黒色系塗料の塗工層が一層の場合で塗工量が少ないとピンホール等が生じそこから光が漏洩する危険性がある。したがって、２層又は３層等の複数層にすればたとえピンホールがあろうとも他の黒色系塗料による塗工層によって被覆されるので強光源からの光の漏洩問題は解消される。光を遮る黒色系塗料のカーボンブラック等の固形分濃度は１ｇ中に３０〜５０％とするのが好ましい。
【００１４】
本発明で使用する接着剤としてはＳＢＲ系接着剤やアクリル樹脂系接着剤等が使用される。ここでも廃棄焼却時に有害ガス等を発生させる接着剤は好ましくない。
【００１５】
また強光源からの光を吸収する黒色系顔料を含有する接着剤は、ラテックス、でんぷん、カゼイン等の接着剤中にカーボンブラック等の黒色系顔料を配合したものが使用される。黒色系顔料の配合量は強光源からの光を吸収するに足る量とする。黒色系塗料、接着剤及び黒色系顔料を含有する接着剤の乾燥は熱乾燥、ＵＶ乾燥、電子線乾燥等があるが、要は乾燥時に塗工紙側に黒色系塗料及び黒色系顔料がしみこまないような乾燥が好ましい。通常、熱乾燥、ＵＶ乾燥、電子線乾燥の順に乾燥時間が短くなる。
【００１６】
少なくとも片面塗工された塗工紙の該塗工面に強光源からの光を遮る黒色系塗料からなる高遮光層を形成し、該高遮光層の上に、強光源からの光を吸収する黒色系顔料を含有する接着剤を介して少なくとも片面塗工された別の塗工紙の該塗工面を接着するという、高遮光層と黒色系顔料を含有する接着剤の組合せ使用することにより、より一層、強光源からの光を遮ることができる。
【００１７】
【実施例】
１．高遮光性の判定
２００Ｗの散光式リフレクター球を３０ｍｍの距離から、油性ペン（黒）で文字を書いたサンプルに照射させ、反対面から観察して次の様に判定した。特に不透明度は１００％を確保することを目的とした。不透明度が１００％未満の場合は不適当であると判断した。
・文字が全く見えない場合は○
・文字の影が見える場合は△
・文字が判読できる場合は×
２．接着強度の判定
幅１５ｍｍ×長さ５０ｍｍにカットしたサンプルの両端を手で持ち金属プレートの角に押し当てて、５往復しごいた後サンプルを揉み解して接着界面を目視判定した。
・接着界面からは剥がれずに、基材（コート紙）破壊の場合は○
・接着界面から部分的に剥がれる場合は△
・全面接着界面から剥がれる場合は×
【００１８】
実施例１
Ａ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）（表紙という）の裏面にカーボンブラック塗料を２回塗りして塗工量２０ｇ／ｍ^２（ｗｅｔ（以下に示す実施例、比較例及び従来例で使用する塗料は全てｗｅｔで示す））とした。カーボンブラックの固形分濃度は１ｇ中に３０〜４０％である。表紙に対して裏紙はＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）を使用した。表紙の裏面に塗布したカーボンブラック塗料面と、裏紙の裏面とをＳＢＲ系接着剤６ｇ／ｍ^２（ｗｅｔ（以下に示す実施例、比較例及び従来例で使用する接着剤は全てｗｅｔで示す））で貼り合わせた。得られた高遮光性用紙の坪量は１８４．８ｇ／ｍ^２、厚さ０．１６０ｍｍで、その特性結果を表１に示した。
【００１９】
実施例２
表紙であるＡ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）の裏面にカーボンブラック塗料を１回塗りして塗工量１０ｇ／ｍ^２とした。裏紙であるＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）の裏面にカーボンブラック塗料を１回塗りして塗工量１０ｇ／ｍ^２とした。表紙及び裏紙の各裏面に塗布したカーボンブラック塗料面同士をＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８４．８ｇ／ｍ^２、厚さ０．１６０ｍｍで、その特性結果を表１に示した。
【００２０】
実施例３
表紙であるＡ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））の裏面には塗料を塗布しない。裏紙であるＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）の裏面にカーボンブラック塗料を２回塗りして塗工量２０ｇ／ｍ^２とした。表紙の裏面と裏紙の裏面に塗布したカーボンブラック塗料面同士をＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８５．３ｇ／ｍ^２、厚さ０．１６０ｍｍで、その特性結果を表１に示した。
【００２１】
比較例７
Ａ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）（表紙という）の裏面にカーボンブラック塗料を２回塗りして塗工量２０ｇ／ｍ^２とした。カーボンブラックの固形分濃度は１ｇ中に３０〜４０％である。表紙に対して裏紙はＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）を使用した。表紙の裏面に塗布したカーボンブラック塗料面と、裏紙の裏面とを黒色顔料を配合（１０％）したＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８５．６ｇ／ｍ^２、厚さ０．１６２ｍｍで、その特性結果を表１に示した。
【００２２】
比較例８
Ａ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）（表紙という）の裏面にカーボンブラック塗料を１回塗りして塗工量１０ｇ／ｍ^２とした。カーボンブラックの固形分濃度は１ｇ中に３０〜４０％である。表紙に対して裏紙はＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）の裏面にカーボンブラック塗料を１回塗りして塗工量１０ｇ／ｍ^２とした。表紙の裏面に塗布したカーボンブラック塗料面と、裏紙の裏面に塗布したカーボンブラック塗料面とを黒色顔料を配合（１０％）したＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８５．５ｇ／ｍ^２、厚さ０．１６１ｍｍで、その特性結果を表１に示した。
【００２３】
比較例９
表紙であるＡ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））の裏面には塗料を塗布しない。裏紙であるＡ２マットコート紙（両面上質コート紙：ミューマット（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）の裏面にカーボンブラック塗料を２回塗りして塗工量２０ｇ／ｍ^２とした。表紙の裏面と裏紙の裏面に塗布したカーボンブラック塗料面同士を黒色顔料を配合（１０％）したＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８５．７ｇ／ｍ^２、厚さ０．１６２ｍｍで、その特性結果を表１に示した。
【００２５】
比較例１０
Ａ２コート紙（両面上質コート紙：ミューコート（北越製紙社製））塗工量（両面）３０〜４０ｇ／ｍ^２（ｄｒｙ）（表紙という）の裏面にカーボンブラック塗料を２回塗りして塗工量２０ｇ／ｍ^２とした。カーボンブラックの固形分濃度は１ｇ中に３０〜４０％である。裏紙として非塗工紙（不透明度、インクジェット適性を向上させた非塗工上質紙：キンマリＮ（北越製紙社製））坪量８１．４ｇ／ｍ^２を使用した。表紙の裏面に塗布したカーボンブラック塗料面と裏紙の裏面とをＳＢＲ系接着剤６ｇ／ｍ^２で貼り合わせた。得られた高遮光性用紙の坪量は１８４．３ｇ／ｍ^２、厚さ０．１６８ｍｍで、その特性結果を表１に示した。
【００２６】
比較例１
１層を塗工紙（コート紙Ｂ）８４．９ｇ／ｍ^２、２層は接着剤Ａを３．５ｇ／ｍ^２、３層は厚さ７μのＡｌ箔、４層は下地処理液、５層は接着剤Ｂを６．０ｇ／ｍ^２、６層は塗工紙（コート紙Ｂ）８４．９ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００２７】
比較例２
１層を塗工紙（コート紙Ｂ）８４．９ｇ／ｍ^２、２層は接着剤Ｂを６．０ｇ／ｍ^２、３層は厚さ１２μの蒸着層ＶＭＰＥＴ、４層は下地処理液、５層は接着剤Ｂを６．０ｇ／ｍ^２、６層は塗工紙（コート紙Ｂ）８４．９ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００２８】
比較例３
１層を塗工紙（コート紙Ａ）８４．９ｇ／ｍ^２、２層は接着剤Ｂを６．０ｇ／ｍ^２、３層は厚さ１２μのＰＥＴフィルム、４層は黒色系塗料層(黒コート)で塗工量１０ｇ／ｍ^２（ｗｅｔ）、５層は接着剤Ｂを６．０ｇ／ｍ^２、６層は塗工紙（コート紙Ａ）８４．９ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００２９】
比較例４
１層を塗工紙（コート紙Ｂ）１０４．７ｇ／ｍ^２、２層は接着剤Ｂを６．０ｇ／ｍ^２、３層は蒸着紙７９．１ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００３０】
比較例５
１層を塗工紙（コート紙Ａ）１０４．７ｇ／ｍ^２、２層は接着剤Ｂを６．０ｇ／ｍ^２、３層は厚さ７０μの黒紙特薄口、４層は印刷適性を付与した白色系塗料層(白コート)で塗工量１０ｇ／ｍ^２（ｗｅｔ）とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００３１】
比較例６
１層を塗工紙（コート紙Ａ）８４．９ｇ／ｍ^２、２層は接着剤Ｂを６．０ｇ／ｍ^２、３層は厚さ２５μの黒ＰＥＴフィルム、４層は接着剤Ｂを６．０ｇ／ｍ^２、５層は塗工紙（コート紙Ａ）８４．９ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００３２】
従来例１
１層を非塗工紙（中性紙）６４ｇ／ｍ^２、２層は接着剤Ａを３．５ｇ／ｍ^２、３層は厚さ７μのＡｌ箔、４層は下地処理液、５層は接着剤Ｂを６．０ｇ／ｍ^２、６層は非塗工紙（中性紙）６４ｇ／ｍ^２とし、坪量、厚さ、白色度（表、裏）、高遮光性、接着強度、コスト、リサイクル性のそれぞれを表２に示した。
【００３３】
【表１】

【００３４】
【表２】

【００３５】
【発明の効果】
本発明は、上記の説明から判るように、遮光層を薄く形成しても強光源の光を吸収し、高遮光性が得られ、また黒紙使用による着色顔料等の分散性や歩留低下に起因した隠ぺい性の不均一性の問題が解消され、同様に黒色系接着剤のカーボンブラック分散性不良に起因した不均一な隠ぺい性や、カーボンブラック配合比率の高いことに起因した接着力不足という問題も解消され、再生紙としてリサイクルが可能で、燃えるごみとして焼却でき、廃棄焼却時に有害ガスが発生しない上に焼却残滓の少ない高遮光性用紙を得ることができる。
【００３６】
また、強光源からの光を遮る黒色系塗料からなる重ね塗りした複数層の高遮光層と、強光源からの光を吸収する黒色系顔料を含有する接着剤を組合せ使用することにより、両者の相乗効果により遮光性は一層向上することとなる。
【００３７】
強光源からの光を遮る黒色系塗料は複数回重ねて塗布することによりピンホールに伴なう光の漏洩が解消される。また表紙に両面コートのＡ２コート紙を採用し、裏紙に両面コートのＡ２マットコート紙を採用することにより、表２に示す通り、表紙の白色度に比べ裏紙の白色度の方が数値が高いことから裏紙の方がより白紙の光沢を抑えて目にやさしく、見やすく、読みやすく、しかも黒色系塗料や黒色系顔料のにじみ等がコート面で阻止され、遮光性の低下が解消され、かつ白色度も低下することがない。したがって、表紙の表面は塗工面であると多色刷り等の印刷適性が良好である。また塗工紙の裏紙を両面塗工のＡ２マットコート紙を採用したことにより表紙のＡ２コート紙に比べペン書き等の書きこみが容易となる。
【００３８】
裏紙は接着剤を介して非塗工紙を採用することも出来る。塗工紙に比べてより一層ペン書き等の書きこみが良好となる。[0001]
BACKGROUND OF THE INVENTION
The present invention is a card such as a speed lottery or a playing card or a paper on which personal information is recorded, and other various papers, and characters, numbers, symbols, etc. printed and recorded on the front surface are unreadable by a strong light source from the back side, The present invention also relates to highly light-shielding paper that is recyclable and has little incineration residue during incineration.
[0002]
[Prior art]
A speed lottery is a winning lottery if three of the same grade appear, and you can receive a winning according to that grade. The numbers printed on the surface are concealed with a paste containing aluminum powder, etc., and at the time of purchase, the concealed part is checked with three coins to check the number, but with coins etc. It is important that the number is not readable even if a strong light source is applied from the back before squeezing.
[0003]
In this type of conventional speed lottery, an aluminum foil is interposed in the middle of the paper so that the number cannot be read even if a strong light source is applied from the back side.
In addition, a base paper not provided with a concealing layer containing aluminum powder and a base paper provided with a concealing layer containing aluminum powder are bonded together using an aqueous acrylic resin-based paste so that the concealing layer is in the middle of both. is there. Alternatively, there is a paper in which a base paper provided with a concealing layer for irregularly reflecting or scattering light from a strong light source and a base paper not provided with the concealing layer are bonded together with an adhesive. Further, there are those in which a black paper that absorbs light is interposed between the base papers, and those in which the base paper and the base paper are bonded with an adhesive in which carbon black or the like is dispersed.
[0004]
[Problems to be solved by the invention]
However, in the case where an aluminum foil (Al foil) is interposed in the middle of the paper, it has a strong hiding power that the numbers printed on the front side cannot be read even if a strong light source is applied from the back side, There are problems such as difficulty in recycling after use, and inability to treat as burnable garbage during incineration. In addition, when a base paper provided with a concealing layer containing aluminum powder is used, there is a problem that it cannot be handled as burnable garbage at the time of incineration. In addition, the base paper provided with a concealing layer that diffusely reflects, scatters, etc. the light from the strong light source and the base paper not provided with the concealing layer are bonded together with an adhesive, and the concealing layer must be formed thick. In other words, it was not suitable for applications requiring thinness. In addition, black paper has problems such as poor yield that carbon black is difficult to fix to pulp during paper making, and inferior concealment due to poor dispersion. In addition, in order to make a black adhesive, the non-uniformity of concealment due to poor dispersion of carbon black due to the high viscosity due to the adhesive, and insufficient adhesive strength due to high carbon black ratio There was a problem.
[0005]
The present invention has been made in view of the above points. The object of the present invention is to absorb light from a strong light source and to form a thin high light-shielding layer that blocks the light, and to be recycled as recycled paper and to burn. The object is to provide highly light-shielding paper that can be incinerated as waste and has little incineration residue.
[0006]
[Means for Solving the Problems]
The highly light-shielding paper according to the present invention is a two-sided coated A2 coated paper using a coating pigment of an inorganic pigment such as kaolin or calcium carbonate, which does not generate harmful gases during incineration, and the backing paper is harmful during incineration It is formed of A2 mat coated paper with double-sided coating using inorganic pigment coating pigments such as kaolin and calcium carbonate that do not generate gas, and consists of a black paint that blocks light from a strong light source on the entire back surface of the cover. A plurality of high light-shielding layers are formed by recoating, or a plurality of high light-shielding layers made of a black paint that blocks light from a strong light source are formed on the entire back surface of the backing paper by recoating. Adhering the entire back surface of the backing paper or the entire back surface of the cover sheet with an adhesive that does not generate harmful gases upon disposal incineration, such as SBR adhesive and acrylic resin adhesive, on the light shielding layer and the black System paint total coating amount in the wet state is 20 to 30 g / m ^2, and a solid concentration of black-color-based paint, characterized in that from 30 to 50% in 1g.
[0007]
Further, the highly light-shielding paper according to the present invention is a double-sided coated A2 coated paper using a coating pigment of an inorganic pigment such as kaolin or calcium carbonate, which does not generate harmful gases during disposal incineration, and the backing paper is disposed during disposal incineration. Formed with double-coated A2 mat coated paper using inorganic pigment coating pigments such as kaolin and calcium carbonate, which do not generate harmful gases, and from a strong light source on the entire back surface of the cover and the entire back surface of the back paper A high-light-shielding layer made of a black paint that shields the light from each other is formed. The black paint is wet and the total coating amount is 20 to 30 g / m ² , and the solid content concentration of the black paint is 30 to 50 in 1 g. % Characterized in that there.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The coated paper used in the present invention includes art paper, fine coated paper, medium coated paper, lightweight coated paper, fine coated paper, cast coated paper, embossed paper, and other coated paper. Any of the coating methods may be used, but in the case of single-side coating, curling is likely to occur, and therefore, it is preferable to perform anti-curling processing on the back surface. In addition, when the front and back surfaces are bonded using coated paper with a high light-shielding layer and an adhesive interposed therebetween, writing properties such as pen writing are improved when the back surface side is a non-coated surface. Inorganic pigments such as kaolin (clay), calcium carbonate, satin white, titanium dioxide, and aluminum hydroxide are used as the coating paper paint (coating color). Organic pigments based on plastic polymers may be used as long as they do not generate harmful gases during disposal by incineration.
The coated surface of the coated paper has good printability such as multicolor printing.
[0012]
The reason why the coated paper is used in principle in the present invention and the non-coated paper is not used is that in the adhesive containing the black pigment in the high light shielding layer and the black pigment that absorbs light from the strong light source described later. This is to prevent the absorption of light from the strong light source, the whiteness, and the like from decreasing due to the paint or pigment moving due to the black pigment oozing to the base paper. Therefore, in the case of single-side coated paper, it is necessary to form a high light-shielding layer made of a black paint that blocks light from a strong light source and an adhesive containing a black pigment on the coated surface side.
However, although the principle is that the coated papers are bonded together, non-coated paper may be employed as the paper corresponding to the backing paper. It is necessary not to apply an adhesive having a black paint or black pigment on the non-coated paper side. Non-coated paper can be expected to further improve writing characteristics such as pen writing compared to coated paper.
[0013]
The high light-shielding layer paint made of a black paint that blocks light from a strong light source used in the present invention is called a so-called black coat. For example, a black paint such as carbon black is employed. The coating amount of the black paint is 10 to 30 g / m ² per time in a wet state. For example, one or more times of overcoating are performed by gravure coating or other means. If the coating layer of the black paint is a single layer and the coating amount is small, there is a risk that pinholes will occur and light will leak from there. Accordingly, if a plurality of layers such as two layers or three layers are used, the problem of light leakage from the strong light source can be solved because even if there is a pinhole, it is covered with a coating layer of other black paint. The solid content concentration of carbon black or the like of the black paint that blocks light is preferably 30 to 50% in 1 g.
[0014]
As an adhesive used in the present invention, an SBR adhesive, an acrylic resin adhesive, or the like is used. Here too, an adhesive that generates a harmful gas or the like during waste incineration is not preferable.
[0015]
As the adhesive containing a black pigment that absorbs light from a strong light source, a black pigment such as carbon black is used in an adhesive such as latex, starch, or casein. The black pigment content is sufficient to absorb light from a strong light source. Drying of black paints, adhesives and adhesives containing black pigments includes thermal drying, UV drying, electron beam drying, etc. In short, black paint and black pigments are soaked on the coated paper side during drying. Drying is preferred. Usually, drying time becomes short in order of heat drying, UV drying, and electron beam drying.
[0016]
A black layer that absorbs light from a strong light source is formed on the coated surface of at least one side of the coated paper by forming a high light shielding layer made of a black paint that blocks light from the strong light source. By using a combination of a high light-shielding layer and an adhesive containing a black pigment, by adhering the coated surface of another coated paper coated at least on one side via an adhesive containing a pigment based on Further, light from the strong light source can be blocked.
[0017]
【Example】
1. Determination of high light shielding property A 200 W diffused reflector sphere was irradiated from a distance of 30 mm onto a sample on which characters were written with an oil pen (black), and observed from the opposite surface to make the following determination. In particular, the aim was to ensure 100% opacity. When the opacity was less than 100%, it was judged to be inappropriate.
・ ○
・ If you can see the shadow of the letter
・ If the text is readable, ×
2. Judgment of Adhesive Strength A sample cut to a width of 15 mm and a length of 50 mm was held by hand and pressed against a corner of a metal plate, and after 5 reciprocations, the sample was squeezed to visually determine the adhesive interface.
・ If the base material (coated paper) is destroyed without peeling from the adhesive interface, ○
・ △ is peeled off partially from the adhesive interface
・ If peeling from the entire adhesive interface ×
[0018]
Example 1
A2 coated paper (double-sided high-quality coated paper: Mu Coat (made by Hokuetsu Paper Co., Ltd.)) Coating amount (both sides) 30-40 g / m ² (dry) (referred to as cover) is coated with carbon black paint twice. The work amount was 20 g / m ² (wet (all paints used in Examples, Comparative Examples, and Conventional Examples shown below are indicated by wet)). The solid content concentration of carbon black is 30 to 40% in 1 g. A2 mat coated paper (double-sided high-quality coated paper: mu mat (manufactured by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) of 30 to 40 g / m ² (dry) was used as the backing paper. SBR adhesive 6 g / m ² (wet (all the adhesives used in the following examples, comparative examples and conventional examples are indicated by wet). )). The basis weight of the obtained high light-shielding paper was 184.8 g / m ² and the thickness was 0.160 mm. The characteristic results are shown in Table 1.
[0019]
Example 2
A2 coated paper (double-sided high-quality coated paper: mu coat (manufactured by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² The back surface of (dry) was coated with carbon black paint once to give a coating amount of 10 g / m ² . A2 mat coated paper (double-sided high-quality coated paper: mu mat (manufactured by Hokuetsu Paper Industries)) coating amount (both sides) 30-40 g / m ^{2 as} backing paper The back surface of (dry) was coated with carbon black paint once to give a coating amount of 10 g / m ² . Cover and SBR adhesive with carbon black paint faces coated on each rear surface of the backing paper 6 g / m ² I stuck together. The basis weight of the obtained high light-shielding paper is 184.8 g / m ^2. The thickness is 0.160 mm and the characteristic results are shown in Table 1.
[0020]
Example 3
A paint is not applied to the back surface of the A2 coated paper (double-sided high-quality coated paper: Mu Coat (made by Hokuetsu Paper Co., Ltd.)) as the cover. A2 mat coated paper (double-sided high-quality coated paper: Mu mat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) of 30 to 40 g / m ² (dry) is applied twice on the back surface of carbon black paint. The coating amount was 20 g / m ² . The carbon black paint surfaces applied to the back surface of the cover and the back surface of the back paper were bonded together with an SBR adhesive 6 g / m ² . The basis weight of the obtained high light-shielding paper was 185.3 g / m ² and the thickness was 0.160 mm. The characteristic results are shown in Table 1.
[0021]
Comparative Example 7
A2 coated paper (double-sided high-quality coated paper: mu coat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² (Dry) The carbon black paint was applied twice on the back surface of the cover (referred to as the cover) to give a coating amount of 20 g / m ² . The solid content concentration of carbon black is 30 to 40% in 1 g. The backing paper is A2 mat coated paper (double-sided high-quality coated paper: mu mat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² (Dry) was used. SBR-based adhesive 6 g / m ^{2 in} which a black pigment is blended (10%) between the carbon black paint surface applied to the back surface of the cover and the back surface of the back paper I stuck together. The basis weight of the obtained high light-shielding paper is 185.6 g / m ^2. Table 1 shows the characteristic results of the thickness of 0.162 mm.
[0022]
Comparative Example 8
A2 coated paper (double-sided high-quality coated paper: mu coat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² (Dry) The carbon black paint was applied once to the back surface of the cover (referred to as the cover) to give a coating amount of 10 g / m ² . The solid content concentration of carbon black is 30 to 40% in 1 g. The backing paper is A2 mat coated paper (double-sided high-quality coated paper: mu mat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² The back surface of (dry) was coated with carbon black paint once to give a coating amount of 10 g / m ² . SBR adhesive 6 g / m ^{2 in} which a black pigment is blended (10%) between the carbon black paint surface applied to the back of the cover and the carbon black paint applied to the back of the back paper. I stuck together. The basis weight of the obtained high light-shielding paper is 185.5 g / m ^2. Table 1 shows the characteristic results of the thickness of 0.161 mm.
[0023]
Comparative Example 9
A paint is not applied to the back surface of the A2 coated paper (double-sided high-quality coated paper: Mu Coat (made by Hokuetsu Paper Co., Ltd.)) as the cover. A2 mat coated paper (double-sided high-quality coated paper: mu mat (manufactured by Hokuetsu Paper Industries)) coating amount (both sides) 30-40 g / m ^{2 as} backing paper The back side of (dry) was coated with carbon black paint twice to give a coating amount of 20 g / m ² . SBR adhesive 6 g / m ² in which carbon black paint surfaces applied to the back side of the cover and the back side of the back paper are blended with black pigment (10%). I stuck together. The basis weight of the obtained high light-shielding paper is 185.7 g / m ^2. Table 1 shows the characteristic results of the thickness of 0.162 mm.
[0025]
Comparative Example 10
A2 coated paper (double-sided high-quality coated paper: mu coat (made by Hokuetsu Paper Co., Ltd.)) coating amount (both sides) 30-40 g / m ² (Dry) The carbon black paint was applied twice on the back surface of the cover (referred to as the cover) to give a coating amount of 20 g / m ² . The solid content concentration of carbon black is 30 to 40% in 1 g. Non-coated paper (uncoated high-quality paper with improved opacity and inkjet suitability: Kinmari N (manufactured by Hokuetsu Paper Industries)) basis weight of 81.4 g / m ² was used as the backing paper. The carbon black paint surface applied to the back side of the cover and the back side of the back paper are made of SBR adhesive 6 g / m ² I stuck together. The basis weight of the obtained high light-shielding paper is 184.3 g / m ^2. The thickness is 0.168 mm and the characteristic results are shown in Table 1.
[0026]
Comparative Example 1
The first layer coated paper (coated paper B) 84.9g ^{/ m} 2, 2 layers of adhesive A 3.5g ^{/ m} 2, 3 layers thick 7 microns Al foil, four layers undercoating liquid, 5 layer is an adhesive B 6.0g ^{/ m} 2, 6-layer and coated paper (coated paper B) 84.9 g / ^{m 2,} the basis weight, thickness, whiteness (Table, back), high light-shielding property, Table 2 shows the adhesive strength, cost, and recyclability.
[0027]
Comparative Example 2
The first layer coated paper (coated paper B) 84.9g ^{/ m} 2, 2 layers of adhesive B 6.0g ^{/ m} 2, 3 layers deposited layer having a thickness of 12μ VMPET, 4 layers undercoating liquid, 5-layer adhesive B the 6.0 g ^{/ m} 2, 6 layers and coated paper (coated paper B) 84.9 g / ^{m 2,} the basis weight, thickness, whiteness (Table, back), high light-shielding property Table 2 shows the adhesive strength, cost, and recyclability.
[0028]
Comparative Example 3
One layer coated paper (coated paper A) 84.9g ^{/ m} 2, 2 layers of adhesive B 6.0g ^{/ m} 2, 3 layers PET film having a thickness of 12 [mu, 4 layers blackish paint layer ( coating amount ^{10 g} / m 2 in black coat) (wet), 5 layer adhesive B 6.0g ^{/ m} 2, 6 layers and coated paper (coated paper a) 84.9g / ^{m 2,} the basis weight Table 2 shows thickness, whiteness (front and back), high light-shielding properties, adhesive strength, cost, and recyclability.
[0029]
Comparative Example 4
The first layer coated paper (coated paper B) 104.7g ^{/ m} 2, 2 layers and adhesive B 6.0g ^{/ m} 2, 3 layers and metallized paper 79.1 g / ^{m 2,} the basis weight, thickness Table 2 shows whiteness (front and back), high light-shielding properties, adhesive strength, cost, and recyclability.
[0030]
Comparative Example 5
1 layer is coated paper (Coated paper A) 104.7 g / m ² , 2 layer is adhesive B 6.0 g / m ² , 3 layer is 70μ thick black paper special thin mouth, 4 layer is printability With the applied white paint layer (white coat), the coating amount is 10 g / m ² (wet), and each of the basis weight, thickness, whiteness (front and back), high light-shielding properties, adhesive strength, cost, and recyclability Are shown in Table 2.
[0031]
Comparative Example 6
The first layer coated paper (coated paper A) 84.9g ^{/ m} 2, the two-layer black PET film adhesive B 6.0 g ^{/ m} 2, 3-layer thickness 25.mu., a four-layer adhesive B 6.0 g ^{/ m} 2, 5 layers and coated paper (coated paper a) 84.9 g / ^{m 2,} the basis weight, thickness, whiteness (Table, back), high light-shielding properties, adhesive strength, cost, recycled Each sex is shown in Table 2.
[0032]
Conventional Example 1
One layer is non-coated paper (neutral paper) 64 g / m ² , two layers are adhesive A 3.5 g / m ² , three layers are 7 μ thick Al foil, four layers are ground treatment solutions, five layers The adhesive B is 6.0 g / m ² , the 6 layers are non-coated paper (neutral paper) 64 g / m ² , basis weight, thickness, whiteness (front and back), high light-shielding properties, adhesive strength Table 2 shows each of the cost and recyclability.
[0033]
[Table 1]

[0034]
[Table 2]

[0035]
【The invention's effect】
As can be seen from the above description, the present invention absorbs light from a strong light source even when a light shielding layer is formed thin, and high light shielding properties are obtained. The problem of non-uniformity of the concealment due to the non-uniformity is solved, and the non-uniform concealment due to poor carbon black dispersibility of the black adhesive as well as insufficient adhesion due to the high proportion of carbon black This eliminates the problem, and can be recycled as recycled paper, can be incinerated as burnable garbage, and can produce a highly light-shielding paper that generates no harmful gas during incineration and has little incineration residue.
[0036]
In addition, by using a combination of a plurality of multi-layered high light-shielding layers made of black paint that blocks light from a strong light source and an adhesive containing a black pigment that absorbs light from a strong light source, The light blocking effect is further improved by the synergistic effect.
[0037]
The black paint that blocks the light from the strong light source is applied multiple times to eliminate the light leakage accompanying the pinhole. The adopted A2 coated paper of the double-sided coating on the cover, by adopting the A2 matte coated paper of the double-sided coated backing paper, as shown in Table 2, numerical values towards the whiteness of the backing paper than on the whiteness of the cover Because of its high color, the backing paper is more gentle to the eyes with less gloss on the white paper, easy to read, easy to read, and the coating surface prevents black paint and black pigment bleed, etc. In addition, the whiteness does not decrease. Therefore, if the surface of the cover is a coated surface, the printability such as multicolor printing is good. Further, by adopting A2 mat coated paper with double-sided coating as the backing paper of the coated paper, writing such as pen writing becomes easier as compared with the A2 coated paper of the cover .
[0038]
As the backing paper, non-coated paper can also be adopted through an adhesive. Compared to coated paper, writing such as pen writing becomes better.

Claims

The cover is A2 coated paper with double-sided coating using inorganic pigments such as kaolin and calcium carbonate, which does not generate harmful gases during waste incineration, and the backing paper is made of kaolin, calcium carbonate, etc. that does not generate harmful gases during waste incineration. formed respectively A2 matte coated paper both surfaces coated with a coating color of the inorganic pigment, the high light-shielding layer recoating of multiple layers made of a black-based paint to block light from the strong light source on the entire surface of the back surface of the cover Forming a plurality of high light-shielding layers made of a black paint that blocks light from a strong light source on the entire back surface of the backing paper by overcoating , and an SBR adhesive on the high light-shielding layer , if the above blackish paint wet state with adhering waste entire back surface of the entire rear surface or the front page of the backing paper by an adhesive that harmful gas is not generated during incineration such as an acrylic resin-based adhesive High light-shielding paper coating weight of 20 to 30 g / m ^2, and a solid concentration of black-color-based paint, characterized in that from 30 to 50% in 1g.

The cover is A2 coated paper with double-sided coating using inorganic pigments such as kaolin and calcium carbonate, which does not generate harmful gases during waste incineration, and the backing paper is made of kaolin, calcium carbonate, etc. that does not generate harmful gases during waste incineration. Highly light-shielding made of black paint that is formed with A2 mat coated paper with double-sided coating using inorganic pigment coating pigment, and blocks light from strong light source on the entire back surface of the cover and the entire back surface of the back paper Forming each layer, making the high light-shielding layers face each other, and bonding them through an adhesive that does not generate harmful gas during disposal incineration, such as an SBR adhesive and an acrylic resin adhesive, between the opposing high light-shielding layers, The black paint has a total coating amount of 20 to 30 g / m ² in a wet state, and the solid content concentration of the black paint is 30 to 50% in 1 g. for .