JP3619839B2

JP3619839B2 - Glue-coated paper for stamps and method for producing the same

Info

Publication number: JP3619839B2
Application number: JP34864898A
Authority: JP
Inventors: 剛志倉田
Original assignee: 独立行政法人国立印刷局
Priority date: 1998-12-08
Filing date: 1998-12-08
Publication date: 2005-02-16
Anticipated expiration: 2018-12-08
Also published as: JP2000170098A

Description

【０００１】
【発明の属する技術分野】
本発明は、切手用糊塗布紙及びその製造方法に関し、温湿度の環境条件の変化に対してもブロッキング及びカールを生じることがなく、一定の初期接着力を有するとともに、一定の条件下で再剥離可能な切手用糊塗布紙とその製造方法に関するものである。
【０００２】
【従来の技術】
切手は、全国の郵便局又はたばこ小売店等で販売されている。これら販売所では、空調設備の完備されている所から、そうでない所まで様々であり、切手の保管されている環境条件も地域又は季節等により大きく変動する状況にある。したがって、このような広範囲な温度、湿度の環境条件下で、切手が切手同士又は他のものとブロッキングしたり、カールなどの現象を起こすと使用不可能になってしまう。切手用紙としては、必要とされる糊の接着力を維持しつつ、上記のような条件下においてもブロッキングやカール等を生じさせない品質が要求される。
【０００３】
過去においては糊の主成分として、アラビアゴムやデキストリンのような水溶性天然高分子が使用されていた。しかし、これらは耐湿性に欠けるためにグラシン紙を間紙として切手間に挿入するなどしてブロッキングを防止しなくてはならない問題があった。
【０００４】
その後、再湿性接着剤として、ポリビニルエーテル、ポリビニロピロリドン、ポリアクリルアミド、部分ケン化ポリビニルアルコール等の合成高分子が開発され、耐湿性や接着力の点から現在ではポリビニルアルコール（以下、「ＰＶＡ」と称する。）がその中心をなしているが、ＰＶＡ単独で使用される例は少なく、ポリ酢酸ビニル、ポリアクリル酸エステルなどと混合使用されている。一般的に糊の再湿性接着剤として使用されているＰＶＡは、その重合度が高くなるにつれてガラス転移点が高くなり、ブロッキングしにくくなるが、初期接着力、粘度に問題が生じる。一方、ポリ酢酸ビニルエマルション（以下、「ＰＶＡｃエマルション」と称する。）は、ブロッキングしやすくなるが、カールや初期接着力には効果がある。
【０００５】
再湿性接着剤には、使用目的に応じた接着性が要求され、例えば、特開昭５３−１１９３３号公報、特開昭５３−１１９３４公報、特開昭５３−１２４３４０公報、特開昭５３−７２０４９公報に記載されているように、自動包装用に対しては初期接着力が、壁紙、ふすま紙に対してはオープンタイムの長いことが要求される。そのため、要求される糊の接着性に応じて各再湿性接着剤を適切に選定、配合しなければならない。
【０００６】
切手は、その使用用途から上記に述べたブロッキングしにくくなる性質、耐カール性、初期接着力が要求されるのは当然であり、更に、使用者が貼り間違えたり、切手収集家が封筒等の被接着用紙から再剥離する場合には、容易に剥離する性質が望まれる。このように、互いに相反するような特性が要求される製品としては切手、収入印紙類に限られ、市場でもこの種の製品に用いられる糊の開発はなされていなかった。
【０００７】
【発明が解決しようとする課題】
本発明は、切手用糊塗布紙とその製造方法に関するものであって、温湿度の環境条件の変化に対しても、ブロッキング及びカールを生じることなく、一定の初期接着力を有するとともに、一定の条件下で再剥離可能な切手用糊塗布紙とその製造方法を提供するものである。
【０００８】
【課題を解決するための手段】
本発明者は、切手を保管している際に温湿度の環境条件が変化しても、ブロッキング及びカールを生じることなく、貼付時には一定の初期接着力を有するとともに、一定の条件下で再剥離可能な切手用糊塗布紙とその製造方法について鋭意研究を重ねた結果、特定の重合度とケン化度を有するＰＶＡ及び特定のＰＶＡｃエマルション並びにソルビットを特定量の割合で配合した糊液を塗工、乾燥した後、キャレンダ処理することによって、上記の性質を満足させることが可能となる切手用糊塗布紙とその製造方法を見出し、本発明を完成するに至った。
【０００９】
すなわち、本発明の切手用糊塗布紙は、塗工紙の裏面又は原紙の片面に、糊液が塗布、乾燥され、キャレンダに通紙して加圧、仕上げされた糊塗布紙であって、前記糊液は、平均重合度３００〜４００、ケン化度８８±２（ｍｏｌ／％）のＰＶＡを４５〜４９％、可塑剤無添加で最低造膜温度１０〜１５℃のＰＶＡｃエマルションを４５〜４９％、ソルビットを２〜１０％の割合で含有することを特徴とする切手用糊塗布紙である。
【００１０】
また、本発明の切手用糊塗布紙は、ＰＶＡｃエマルションの中に前記エマルションの保護コロイド及び乳化剤として、ケン化度８５〜９０（ｍｏｌ／％）、平均重合度３００〜２５００のＰＶＡが固形分として２５〜４５％の割合で含まれたことを特徴とする切手用糊塗布紙である。
【００１１】
また、本発明の切手用糊塗布紙は、糊塗布量が乾燥重量で１５〜２０ｇ／ｍ２であることを特徴とする切手用糊塗布紙である。
【００１２】
また、本発明の切手用糊塗布紙の製造方法は、塗工紙の裏面又は原紙の片面に、糊液を塗布、乾燥し、キャレンダに通紙して加圧、仕上げする糊塗布紙の製造方法であって、前記面に、平均重合度３００〜４００、ケン化度８８±２（ｍｏｌ／％）のＰＶＡを４５〜４９％、可塑剤無添加で最低造膜温度１０〜１５℃のＰＶＡｃエマルションを４５〜４９％、ソルビットを２〜１０％の割合で含有する前記糊液を塗布、乾燥し、前記キャレンダに通紙して加圧、仕上げすることを特徴とする切手用糊塗布紙の製造方法である。
【００１３】
また、本発明の切手用糊塗布紙の製造方法は、ＰＶＡｃエマルションの中に前記エマルションの保護コロイド及び乳化剤として、ケン化度８５〜９０（ｍｏｌ／％）、平均重合度３００〜２５００のＰＶＡを固形分として２５〜４５％の割合で含ませることを特徴とする切手用糊塗布紙の製造方法である。
【００１４】
また、本発明の切手用糊塗布紙の製造方法は、糊塗布量を乾燥重量で１５〜２０ｇ／ｍ２とすることを特徴とする切手用糊塗布紙の製造方法である。
【００１５】
【発明の実施の形態】
本発明で用いられる原紙は、特に限定されるものではないが、例えば、原紙の坪量としては５０〜１００ｇ／ｍ２程度の範囲で適宜、使用される。原紙の抄造に際して使用するパルプは、木材や木綿等の植物繊維を原料とするＫＰ法やＳＰ法によって得られる化学パルプ、ＧＰ、ＴＭＰ、ＣＴＭＰ、ＣＧＰ、ＳＣＰ等の機械パルプ、漂白パルプ等のいずれかのパルプを適宜、選択して使用できる。抄紙方法についても特に限定されるものではなく、通常の抄紙方法、例えば、抄紙ＰＨ４．５付近で行う酸性抄紙方法又は抄紙ＰＨ７．０付近で行う中性抄紙方法によって抄紙される。また、抄紙機も長網抄紙機、円網抄紙機、長網と円網のコンビネーションマシン、ツインワイヤーを装備した抄紙機、ヤンキー抄紙機等のいずれかの抄紙機を適宜、選択して使用できる。
【００１６】
抄紙原紙にパルプとともに配合される抄紙填料としては、製紙業界で一般に使用されている填料が使用される。例えば、タルク、重質炭酸カルシウム、軽質炭酸カルシウム、クレー、二酸化チタン等が例示される。
【００１７】
なお，原紙中にはパルプ繊維や填料の他に，本発明の目的効果を損なわない範囲で、一般的に使用されている各種の歩留まり向上剤、紙力向上剤、内添サイズ剤、ピッチコントロール剤、消泡剤等の薬品類を適宜、使用できる。
【００１８】
また、顔料として、炭酸カルシウム、カオリン、チタン等の無機顔料や有機顔料を適宜、組み合わせ、接着剤としてスチレン・ブタジエン系共重合体等の接着剤、その他、補助剤として分散剤、増粘剤、消泡剤等を使用し、固形分濃度約６０％の顔料スラリーを調製する。このようにして得られた顔料スラリーを前記要領で得られた原紙の片面に塗工する際は、例えば、ブレードコーター、ロールコーター、エアナイフコーター等の公知の塗工装置を設けたオンマシン又はオフマシンのコーターによって一層又は複層に分けて塗工層を設けることができる。
【００１９】
この際の原紙への顔料スラリーの塗工量は、一般に乾燥重量が１０〜１６ｇ／ｍ２であり、湿潤塗工層の乾燥方式としては、例えば、蒸気乾燥、赤外線ヒーター等の各種方式が適宜、採用される。
【００２０】
本発明の切手用糊塗布紙は、このようにして得られた塗工紙の裏面又は原紙の片面に、平均重合度３００〜４００、ケン化度８８±２（ｍｏｌ／％）のＰＶＡを４５〜４９％、可塑剤無添加で最低造膜温度１０〜１５℃のＰＶＡｃエマルションを４５〜４９％、ソルビットを２〜１０％の割合で含有する糊液が塗布、乾燥され、キャレンダに通紙して加圧、仕上げされているので、温湿度の環境条件が変化しても、ブロッキング及びカールを生じることなく、貼付時には一定の初期接着力を有するとともに、一定の条件下で再剥離可能な切手用糊塗布紙となっている。
【００２１】
【実施例】
以下に、実施例と比較例を挙げて、本発明及びその効果を具体的に説明する。勿論、本発明はこられの実施例に限定されるものではない。
【００２２】
なお、以下の実施例及び比較例では、ＰＶＡの重合度とＰＶＡのケン化度、ＰＶＡｃエマルションの最低造膜温度の各測定方法は、それぞれ、ＪＩＳＫ６７２６、ＪＩＳＫ６８０４の方法によった。
【００２３】
また、以下の実施例及び比較例では、ブロッキング、カール、初期接着力、再剥離性の各評価基準は、以下の基準によることとした。
【００２４】
糊塗布紙とその印刷物をそれぞれ１０束（１束は１００×１００ｍｍのシート１００枚）積み重ね、それぞれに約２４Ｋｇのおもりをのせ、それぞれ２５℃、８５％ＲＨと３０℃、９０％ＲＨの環境条件下で２４時間、４８時間放置し、ブロッキングの発生状態を目視により下記基準に基づいて判定した。その際の判定基準は、◎：ブロッキングなし、○：わずかにブロッキングしたもの、×：完全にブロッキングしたもの、の各基準によった。
【００２５】
５０×５０ｍｍの切手用糊塗布紙及びその印刷物を用意し、２０℃で３３、５５、６５、８８％の各ＲＨの条件下で試験し、８時間後のカール度を図１に示すＪ．ＴＡＰＰＩ「紙のカール試験方法２」のカール度目測用ガラスゲージで測定した。
【００２６】
３０×３５ｍｍの切手用糊塗布紙及びその印刷物をラミネートクラフト紙のクラフト面に、２０℃、６５％ＲＨの室内で通常に切手を使用する場合と同様の方法で吸水スポンジを用いて貼り付け、５秒間隔で引き剥がし、試料が破れるまでの固着所用時間及びクラフト紙の紙層の剥離状態を目視によって判定し、初期接着力を測定した。その際の判定基準は、◎：５秒未満で完全にクラフト紙に接着したもの、○：１５秒未満で完全にクラフト紙に接着したもの、×：１５秒以上でもクラフト紙に完全に接着しないもの、の各基準によった。
【００２７】
１５×１５ｍｍの切手用糊塗布紙及びその印刷物の糊面を水で十分に湿潤させて、ラミネートクラフト紙のクラフト面に貼付した後、水中に浸漬させ、手で切手用紙をクラフト紙から破壊せずに剥がせるまでに要した時間を測定して再剥離性の評価を行った。その際の評価基準は、◎：２分以内で剥離可能なもの、○：５分以内で剥離可能なもの、×：剥離するのに５分以上要するもの、の各基準によった。
【００２８】
（実施例１）
フリーネス（ｃｓｆ）が両者ともに５００ｍｌとなるように叩解したＬＢＫＰ９０％、ＮＢＫＰ１０％からなるパルプスラリ１００％に、タルク（上）（日本タルク社製）１０％を添加した後に、硫酸アルミニウム１．５％、サイズ剤１．０％を添加し、紙料を調製した。この紙料を長網抄紙機で抄紙し、坪量６５ｇ／ｍ２の塗工用原紙を得た。
【００２９】
平均重合度が３５０、ケン化度が８８（ｍｏｌ／％）のＰＶＡ粉末に水を加えて濃度３５％に調製し、８０℃で１時間加熱しながら撹拌し溶解した。次いで、この溶液に固形分濃度４９％、最低造膜温度が１３℃でエマルションの保護コロイド及び乳化剤として、ケン化度８５（ｍｏｌ／％）、平均重合度１０００のＰＶＡを固形分として３０％含むＰＶＡｃエマルションを固形分重量比で１：１で加えた。この溶液の固形分重量との固形分重量比が９８：２になるようにソルビットを加え、撹拌し、溶液の固形分濃度が３６％になるように調製し、糊液を得た。
【００３０】
次に、カオリン８０％、炭酸カルシウム２０％、分散剤０．５％、増粘剤０．５％、ＳＢＲ１５％に調製水を加え、撹拌し、濃度６０％の塗工液を得た。
【００３１】
前記塗工用原紙の片面に前記塗工液を乾燥重量で１３ｇ／ｍ２となるようにブレードコータを用いて塗工し、前記面の裏面に前記糊液を乾燥重量で１８ｇ／ｍ２となるように同様の方法で塗工し、紙水分が５％となるように乾燥した。
【００３２】
得られた糊塗布紙を金属製のヒートロールと弾性ロール各１本からなるソフトカレンダーを用いて、顔料塗工面のみが２回ヒートロールに接触するようにヒートロール温度１００℃、線圧１００Ｋｇ／ｃｍでキャレンダ仕上げを行った。
【００３３】
また、この糊塗布紙のコート面にグラビア印刷適性試験機によるグラビア印刷及びオフセット印刷機によるオフセット印刷を施した印刷物を併せて作製した。
【００３４】
（実施例２）
平均重合度が３５０、ケン化度が８８（ｍｏｌ／％）のＰＶＡが４８％、最低造膜温度が１３℃のＰＶＡｃエマルションが４８％及びソルビットが４％の割合で配合され、ＰＶＡｃエマルション中のＰＶＡの重合度が１５００で、糊塗布量が乾燥重量で１５ｇ／ｍ２であること以外は、実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００３５】
（実施例３）
ＰＶＡの平均重合度が４００、ＰＶＡｃエマルションが、その中にエマルションの保護コロイド及び乳化剤として、ケン化度９０（ｍｏｌ／％）、平均重合度１０００のＰＶＡを固形分として３５％含み、糊塗布量が乾燥重量で２０ｇ／ｍ２であること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００３６】
（実施例４）
ＰＶＡのケン化度が９０（ｍｏｌ／％）、ＰＶＡｃエマルションの最低造膜温度が１５℃、ＰＶＡｃエマルションが、その中にエマルションの保護コロイド及び乳化剤として、ケン化度９０（ｍｏｌ／％）のＰＶＡを固形分として３５％含むこと以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００３７】
（比較例１）
エマルションの保護コロイド及び乳化剤として、ケン化度８５（ｍｏｌ／％）、平均重合度１０００のＰＶＡを固形分として５％含むＰＶＡｃエマルションを配合すること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００３８】
（比較例２）
糊塗布量が乾燥重量で１０ｇ／ｍ２であること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００３９】
（比較例３）
平均重合度３５０、ケン化度８８（ｍｏｌ／％）のＰＶＡを７０％配合し、エマルションの保護コロイド及び乳化剤として、ケン化度８５（ｍｏｌ／％）、平均重合度１０００のＰＶＡを固形分として３０％含むＰＶＡｃエマルションを３０％配合すること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４０】
（比較例４）
ＰＶＡｃエマルションが、平均重合度３５００のＰＶＡを固形分として３０％含むこと以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４１】
（比較例５）
ＰＶＡｃエマルションが、ケン化度６５（ｍｏｌ／％）のＰＶＡを固形分として３０％含むこと以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４２】
（比較例６）
平均重合度が１０００のＰＶＡを４９％配合すること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４３】
（比較例７）
ＰＶＡのケン化度が５０（ｍｏｌ／％）であること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４４】
（比較例８）
最低造膜温度が２５℃のＰＶＡｃエマルションを４９％配合すること以外は実施例１と同様にして切手用糊塗布紙及びその印刷物を作製した。
【００４５】
上記の実施例１〜４及び比較例１〜８で作成した切手用糊塗布紙及びその印刷物についてのブロッキング、カール、初期接着力、再剥離性の評価結果は表１に示す通りであった。
【００４６】
【表１】

【００４７】
上記の表の結果より、実施例１〜４で作製した切手用糊塗布紙及びその印刷物は、どれもブロッキング、カールが良好で、初期接着力、再剥離性も十分に確保されている。しかし、比較例１、５、６で作製した切手用糊塗布紙及びその印刷物は、ブロッキング、カール、再剥離性が悪く、比較例２、３、４、７で作製した切手用糊塗布紙及びその印刷物は、カール、初期接着力が悪く、比較例８で作製した切手用糊塗布紙及びその印刷物は、ブロッキング、カール、初期接着力に問題があった。
【００４８】
【発明の効果】
本発明で得られた切手用糊塗布紙は、温湿度の環境条件の変化に対しても、ブロッキング及びカールが生じることなく、一定の初期接着力を有するとともに、一定の条件下で再剥離可能な切手用糊塗布紙であった。
【図面の簡単な説明】
【図１】Ｊ．ＴＡＰＰＩ「紙のカール試験方法２」のカール度目測用ガラスゲージを示す図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paste-coated paper for stamps and a method for producing the same, and does not cause blocking and curling even when the environmental conditions of temperature and humidity are changed. The present invention relates to a peelable adhesive-coated paper for stamps and a method for producing the same.
[0002]
[Prior art]
Stamps are sold at post offices or tobacco retailers nationwide. These sales offices vary from places where air conditioning facilities are complete to places where they are not, and the environmental conditions where stamps are stored vary greatly depending on the region or season. Therefore, when the stamps are blocked with each other or with other things under such a wide range of temperature and humidity environmental conditions, or a phenomenon such as curling occurs, it becomes unusable. The stamp paper is required to have a quality that does not cause blocking or curling even under the above-mentioned conditions while maintaining the required adhesive strength of the glue.
[0003]
In the past, water-soluble natural polymers such as gum arabic and dextrin have been used as the main component of glue. However, since these have poor moisture resistance, there has been a problem that blocking must be prevented by inserting glassine paper as a slip sheet between stamps.
[0004]
Subsequently, synthetic polymers such as polyvinyl ether, polyvinyl pyrrolidone, polyacrylamide, and partially saponified polyvinyl alcohol were developed as rewet adhesives, and now polyvinyl alcohol (hereinafter referred to as “PVA”) in terms of moisture resistance and adhesive strength. ")"), But PVA alone is rarely used and mixed with polyvinyl acetate, polyacrylate, or the like. In general, PVA used as a re-wetting adhesive for glue has a higher glass transition point as the degree of polymerization becomes higher and it becomes difficult to block, but problems arise in initial adhesive strength and viscosity. On the other hand, polyvinyl acetate emulsion (hereinafter referred to as “PVAc emulsion”) is easy to block, but is effective in curling and initial adhesion.
[0005]
The re-wettable adhesive is required to have an adhesive property according to the purpose of use. For example, Japanese Patent Application Laid-Open Nos. 53-11933, 53-11934, 53-124340, 53- As described in Japanese Patent No. 72049, an initial adhesive force is required for automatic packaging, and a long open time is required for wallpaper and bran paper. Therefore, each rewet adhesive must be appropriately selected and blended according to the required adhesiveness of the glue.
[0006]
It is natural that stamps are required to have the above-mentioned properties that make blocking difficult, curl resistance, and initial adhesive strength due to their intended use. In the case of re-peeling from the adherend paper, it is desirable to have a property of easily peeling. As described above, products that require mutually conflicting characteristics are limited to stamps and revenue stamps, and no paste used for this type of product has been developed in the market.
[0007]
[Problems to be solved by the invention]
The present invention relates to a paste-coated paper for stamps and a method for producing the same, and has a predetermined initial adhesive force without causing blocking and curling with respect to changes in environmental conditions of temperature and humidity, and a certain level. The present invention provides a paste-coated paper for stamps that can be re-peeled under conditions and a method for producing the same.
[0008]
[Means for Solving the Problems]
The inventor does not cause blocking or curling even if the environmental conditions of temperature and humidity change while storing stamps, and has a certain initial adhesive force when applied and re-peeling under certain conditions As a result of diligent research on paste-applied paper for stamps and its manufacturing method, we applied PVA having a specific degree of polymerization and saponification, a specific PVAc emulsion, and a paste containing a specific amount of sorbit After drying, the paper was calendered to find a paste-coated paper for stamps that can satisfy the above properties and a method for producing the same, and the present invention has been completed.
[0009]
That is, the paste-coated paper for stamps of the present invention is a paste-coated paper that has been coated with a paste solution on the back surface of the coated paper or one side of the base paper, dried, passed through a calendar, pressed, and finished. The paste solution is 45 to 49% of PVA having an average polymerization degree of 300 to 400 and a saponification degree of 88 ± 2 (mol /%), and 45 to 45% of a PVAc emulsion having a minimum film forming temperature of 10 to 15 ° C. with no plasticizer added. It is a paste-coated paper for stamps, characterized by containing 49% and sorbit in a proportion of 2 to 10%.
[0010]
Moreover, the paste-coated paper for stamps of the present invention has a saponification degree of 85 to 90 (mol /%) and an average polymerization degree of 300 to 2500 as a solid content as a protective colloid and an emulsifier of the emulsion in a PVAc emulsion. It is a paste-coated paper for stamps characterized by being contained at a ratio of 25 to 45%.
[0011]
The paste-coated paper for stamps of the present invention is a paste-coated paper for stamps, wherein the amount of glue applied is 15 to 20 g / m 2 in terms of dry weight.
[0012]
In addition, the method for producing a paste-coated paper for stamps according to the present invention is a method for producing a paste-coated paper in which a paste solution is applied to the back side of a coated paper or one side of a base paper, dried, passed through a calendar, and pressed and finished. A PVAc having an average polymerization degree of 300 to 400 and a saponification degree of 88 ± 2 (mol /%) of 45 to 49% on the surface, and a minimum film forming temperature of 10 to 15 ° C. without adding a plasticizer. A paste-coated paper for stamps, wherein the paste solution containing 45 to 49% of emulsion and 2 to 10% of sorbite is applied, dried, passed through the calendar and pressed and finished. It is a manufacturing method.
[0013]
Moreover, the manufacturing method of the paste application | coating paper for stamps of this invention is PVA of saponification degree 85-90 (mol /%) and average polymerization degree 300-2500 as a protective colloid and an emulsifier of the said emulsion in PVAc emulsion. It is a manufacturing method of the paste application | coating paper for stamps characterized by including in the ratio of 25 to 45% as solid content.
[0014]
Moreover, the manufacturing method of the paste application | coating paper for stamps of this invention is a manufacturing method of the paste application | coating paper for stamps characterized by making paste application amount into 15-20 g / m <2> by dry weight.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Although the base paper used by this invention is not specifically limited, For example, as a basic weight of a base paper, it uses suitably in the range of about 50-100 g / m2. Pulp to be used for papermaking can be any of chemical pulp obtained by KP method or SP method using plant fibers such as wood and cotton, mechanical pulp such as GP, TMP, CTMP, CGP, SCP, bleached pulp, etc. Such pulp can be appropriately selected and used. The papermaking method is not particularly limited, and papermaking is performed by a normal papermaking method, for example, an acidic papermaking method performed near papermaking PH4.5 or a neutral papermaking method performed near papermaking PH7.0. In addition, the paper machine can be selected and used as appropriate, such as a long net paper machine, a circular net paper machine, a combination machine of a long net and a circular net, a paper machine equipped with twin wires, and a Yankee paper machine. .
[0016]
As the papermaking filler to be blended with the pulp in the papermaking base paper, fillers generally used in the papermaking industry are used. Examples include talc, heavy calcium carbonate, light calcium carbonate, clay, titanium dioxide and the like.
[0017]
In addition to pulp fibers and fillers, the base paper contains various yield improvers, paper strength improvers, internal sizing agents, pitch control, and the like as long as the object effects of the present invention are not impaired. Chemicals such as agents and antifoaming agents can be used as appropriate.
[0018]
In addition, as a pigment, an inorganic pigment such as calcium carbonate, kaolin, titanium, or an organic pigment is appropriately combined, an adhesive such as a styrene / butadiene copolymer as an adhesive, and a dispersant, a thickener as an auxiliary, An antifoaming agent or the like is used to prepare a pigment slurry having a solid concentration of about 60%. When coating the pigment slurry thus obtained on one side of the base paper obtained as described above, for example, an on-machine or off-machine provided with a known coating device such as a blade coater, roll coater, air knife coater, etc. The coating layer can be provided in a single layer or multiple layers by a coater of the machine.
[0019]
The coating amount of the pigment slurry on the base paper at this time is generally 10 to 16 g / m 2 in dry weight, and as a drying method of the wet coating layer, for example, various methods such as steam drying and infrared heater are appropriately used. Adopted.
[0020]
In the paste-coated paper for stamps of the present invention, 45% of PVA having an average degree of polymerization of 300 to 400 and a degree of saponification of 88 ± 2 (mol /%) is formed on the back side of the coated paper thus obtained or on one side of the base paper. ~ 49%, 45 to 49% PVAc emulsion with a minimum film forming temperature of 10 to 15 ° C with no plasticizer added, and a paste containing 2 to 10% sorbite is applied, dried, and passed through the calendar Because it is pressurized and finished, it has a certain initial adhesive strength when it is applied, and it can be re-peeled under certain conditions without blocking and curling even if the environmental conditions of temperature and humidity change. It is a glue-coated paper.
[0021]
【Example】
Hereinafter, the present invention and its effects will be described in detail with reference to examples and comparative examples. Of course, the invention is not limited to these examples.
[0022]
In the following Examples and Comparative Examples, the measurement methods of the polymerization degree of PVA, the saponification degree of PVA, and the minimum film forming temperature of the PVAc emulsion were based on the methods of JIS K 6726 and JIS K 6804, respectively.
[0023]
In the following examples and comparative examples, the evaluation criteria for blocking, curling, initial adhesive force, and removability were determined according to the following criteria.
[0024]
Each stack of glue-coated paper and its printed material is stacked in 10 stacks (1 bundle is 100 sheets of 100 x 100 mm), and each weighs about 24 kg, and environmental conditions of 25 ° C, 85% RH, 30 ° C and 90% RH, respectively. The sample was allowed to stand for 24 hours and 48 hours, and the occurrence of blocking was visually determined based on the following criteria. Judgment criteria at that time were based on the following criteria: A: No blocking, O: Slightly blocked, X: Completely blocked.
[0025]
A 50 × 50 mm paste-coated paper for stamps and printed matter thereof were prepared and tested at 20 ° C. under conditions of 33, 55, 65, and 88% RH, and the curl degree after 8 hours is shown in FIG. It was measured with a glass gauge for curl degree measurement of TAPPI “Paper Curl Test Method 2”.
[0026]
Paste the 30 × 35mm glue-coated paper for stamps and the printed matter on the kraft surface of laminated kraft paper using a water-absorbing sponge in the same way as when using stamps in a room at 20 ° C and 65% RH. After peeling off at intervals of 5 seconds, the time required for fixing until the sample was broken and the peeled state of the paper layer of the kraft paper were visually determined to measure the initial adhesive force. Judgment criteria in this case are: ◎: completely adhered to kraft paper in less than 5 seconds, ○: completely adhered to kraft paper in less than 15 seconds, ×: not completely adhered to kraft paper even in 15 seconds or more According to the standards of things.
[0027]
The 15x15mm stamp paste paper and the printed surface of the printed material are sufficiently moistened with water and applied to the kraft surface of the laminated kraft paper, then immersed in water, and the stamp paper is destroyed from the kraft paper by hand. The re-peelability was evaluated by measuring the time required for peeling without peeling. The evaluation criteria at that time were based on the following criteria: ◎: peelable within 2 minutes, ○: peelable within 5 minutes, ×: take 5 minutes or longer to peel.
[0028]
(Example 1)
After adding 10% talc (above) (manufactured by Nippon Talc Co., Ltd.) to 100% pulp slurry consisting of 90% LBKP and 10% NBKP beaten so that both have a freeness (csf) of 500 ml, 1.5% aluminum sulfate, A paper stock was prepared by adding 1.0% of a sizing agent. This stock was made with a long paper machine to obtain a base paper for coating having a basis weight of 65 g / m2.
[0029]
Water was added to a PVA powder having an average degree of polymerization of 350 and a saponification degree of 88 (mol /%) to prepare a concentration of 35%, and the mixture was stirred and dissolved while heating at 80 ° C. for 1 hour. Next, this solution contains PVA having a saponification degree of 85 (mol /%) and an average polymerization degree of 1000 as a solid content of 30% as a protective colloid and an emulsifier of the emulsion at a solid content concentration of 49% and a minimum film forming temperature of 13 ° C. The PVAc emulsion was added at a solids weight ratio of 1: 1. Sorbite was added so that the weight ratio of the solid content to the solid content weight of this solution was 98: 2, stirred, and adjusted so that the solid content concentration of the solution was 36% to obtain a paste solution.
[0030]
Next, prepared water was added to 80% kaolin, 20% calcium carbonate, 0.5% dispersant, 0.5% thickener and 15% SBR and stirred to obtain a coating solution having a concentration of 60%.
[0031]
The coating liquid is applied on one side of the base paper for coating using a blade coater so that the dry weight is 13 g / m 2, and the paste liquid is applied on the back surface of the surface to a dry weight of 18 g / m 2. The paper was coated in the same manner and dried so that the paper moisture was 5%.
[0032]
Using the soft calender made of a metal heat roll and an elastic roll, the paste-coated paper thus obtained was heated at a heat roll temperature of 100 ° C. and a linear pressure of 100 kg / kg so that only the pigment coated surface was in contact with the heat roll twice. Calendar finishing was performed in cm.
[0033]
Moreover, the printed surface which produced the gravure printing by the gravure printing aptitude test machine and the offset printing by the offset printing machine on the coating surface of this paste application paper was produced together.
[0034]
(Example 2)
48% PVA having an average degree of polymerization of 350, a saponification degree of 88 (mol /%), 48% of a PVAc emulsion having a minimum film-forming temperature of 13 ° C., and 4% of sorbite were blended. A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that the polymerization degree of PVA was 1500 and the amount of paste applied was 15 g / m 2 in terms of dry weight.
[0035]
(Example 3)
The average degree of polymerization of PVA is 400, and the PVAc emulsion contains 35% of PVA having a saponification degree of 90 (mol /%) and an average degree of polymerization of 1000 as a solid content as a protective colloid and an emulsifier of the emulsion. A paste-coated paper for stamps and a printed matter thereof were prepared in the same manner as in Example 1 except that the weight of dry weight was 20 g / m2.
[0036]
(Example 4)
PVA having a saponification degree of 90 (mol /%), a minimum film-forming temperature of the PVAc emulsion of 15 ° C., and a PVAc emulsion as a protective colloid and emulsifier of the emulsion as a saponification degree of 90 (mol /%) A paste-coated paper for stamps and a printed matter thereof were prepared in the same manner as in Example 1 except that 35% was included as a solid content.
[0037]
(Comparative Example 1)
As a protective colloid and an emulsifier for the emulsion, a paste for stamps was applied in the same manner as in Example 1 except that a PVAc emulsion containing 5% of PVA having a saponification degree of 85 (mol /%) and an average polymerization degree of 1000 as a solid content was blended. Paper and printed matter were prepared.
[0038]
(Comparative Example 2)
A paste-coated paper for stamps and printed matter thereof were produced in the same manner as in Example 1 except that the amount of paste applied was 10 g / m 2 in terms of dry weight.
[0039]
(Comparative Example 3)
70% PVA having an average polymerization degree of 350 and a saponification degree of 88 (mol /%) is blended, and as a protective colloid and an emulsifier for the emulsion, a PVA having a saponification degree of 85 (mol /%) and an average polymerization degree of 1000 is used as a solid content. A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that 30% of a 30% PVAc emulsion was blended.
[0040]
(Comparative Example 4)
A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that the PVAc emulsion contained 30% of PVA having an average polymerization degree of 3500 as a solid content.
[0041]
(Comparative Example 5)
A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that the PVAc emulsion contained 30% of PVA having a saponification degree of 65 (mol /%) as a solid content.
[0042]
(Comparative Example 6)
A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that 49% of PVA having an average polymerization degree of 1000 was blended.
[0043]
(Comparative Example 7)
Except that the degree of saponification of PVA was 50 (mol /%), a paste-coated paper for stamps and printed matter thereof were produced in the same manner as in Example 1.
[0044]
(Comparative Example 8)
A paste-coated paper for stamps and printed matter thereof were prepared in the same manner as in Example 1 except that 49% of a PVAc emulsion having a minimum film-forming temperature of 25 ° C. was blended.
[0045]
Table 1 shows the evaluation results of blocking, curling, initial adhesive force, and removability of the paste-coated paper for stamps prepared in Examples 1 to 4 and Comparative Examples 1 to 8 and the printed matter.
[0046]
[Table 1]

[0047]
From the results of the above table, the post-stamp glue-coated paper and printed matter produced in Examples 1 to 4 have good blocking and curling, and sufficient initial adhesion and removability are ensured. However, the paste-coated paper for stamps produced in Comparative Examples 1, 5, and 6 and the printed matter thereof have poor blocking, curling, and removability, and the paste-coated paper for stamps produced in Comparative Examples 2, 3, 4, and 7 and The printed matter had poor curl and initial adhesive strength, and the paste-coated paper for stamps produced in Comparative Example 8 and the printed matter had problems with blocking, curling and initial adhesive strength.
[0048]
【The invention's effect】
The glue-coated paper for stamps obtained in the present invention has a certain initial adhesive force and can be re-peeled under certain conditions without blocking and curling even when the environmental conditions of temperature and humidity are changed. It was a paste-coated paper for stamps.
[Brief description of the drawings]
FIG. The figure which shows the glass gauge for curl degree measurement of TAPPI "paper curl test method 2".

Claims

A glue-coated paper that has been coated with a glue solution on the surface of the coated paper or one side of the base paper, dried, passed through a calendar, pressed and finished,
The paste is 45 to 49% polyvinyl alcohol (PVA) having an average polymerization degree of 300 to 400 and a saponification degree of 88 ± 2 (mol /%),
45 to 49% of polyvinyl acetate emulsion (PVAc emulsion) with no plasticizer added and a minimum film forming temperature of 10 to 15 ° C,
Sorbet is composed of 2-10%,
In the polyvinyl acetate emulsion, polyvinyl alcohol (PVA) having a saponification degree of 85 to 90 (mol /%) and an average polymerization degree of 300 to 2500 is blended as a solid content in a proportion of 25 to 45% as a protective colloid and an emulsifier. And
The paste application paper for stamps, wherein the application amount of the paste is 15 to 20 g / m ² in terms of dry weight .

A method for producing a paste-coated paper in which a paste solution is applied to the back surface of a coated paper or one side of a base paper, dried, passed through a calendar, pressed, and finished.
45-49% polyvinyl alcohol (PVA) having an average polymerization degree of 300-400 and a saponification degree of 88 ± 2 (mol /%),
As a protective colloid and an emulsifier, a minimum film-forming temperature of 10 to 10 without addition of a plasticizer containing polyvinyl alcohol (PVA) having a saponification degree of 85 to 90 (mol /%) and an average polymerization degree of 300 to 2500 as a solid content. 45-49% polyvinyl acetate emulsion (PVAc emulsion) at 15 ° C,
A paste containing 2-10% sorbit
A method for producing a paste-coated paper for stamps, characterized in that it is applied in a dry weight of 15 to 20 g / m ² , dried, passed through the calendar, pressed and finished .