JP4093656B2

JP4093656B2 - Resin for printing ink

Info

Publication number: JP4093656B2
Application number: JP33746098A
Authority: JP
Inventors: 信人寺田; 雅行上田; 憲明畑
Original assignee: Harima Chemical Inc
Current assignee: Harima Chemical Inc
Priority date: 1998-11-27
Filing date: 1998-11-27
Publication date: 2008-06-04
Anticipated expiration: 2018-11-27
Also published as: JP2000159867A

Description

【０００１】
【発明の属する技術分野】
本発明は、オフセット用印刷において、優れたインキ性能と、印刷作業性を有する印刷インキ用樹脂及びこの印刷インキ用樹脂を用いた印刷用インキに関する。
【０００２】
【従来の技術】
オフセット用印刷は印刷に広く用いられている代表的な印刷方式である。この方式は、熱によってインキを乾燥させるヒートセット式のオフセット輪転印刷と乾性油を触媒を用いて硬化、乾燥させる枚葉式印刷方式がある。この印刷に用いられるインキを構成する樹脂として、一般的には天然物であるロジンをフェノール樹脂、特にレゾール樹脂で変性したロジンフェノール樹脂が用いられている。
【０００３】
このロジンフェノール樹脂は、ロジンを樹脂骨格中に有することにより、顔料との濡れ性が向上し、顔料が均一分散しやすいという利点を有する。このロジンがフェノールで変性されている理由は、ロジンそのものは、高分子重合を起こさないモノカルボン酸類であるため、架橋構造を導入する必要があるためである。
【０００４】
さらにフェノール樹脂の合成には、フェノールとホルムアルデヒド及びアルカリ又は酸触媒が用いられているため、ロジンフェノール樹脂の合成にはホルムアルデヒドは合成上必須な構成成分であるといえる。
【０００５】
ところが、ヒートセット式のオフセット印刷では印刷インキにかなりの熱がかかるため、この熱によっては、ロジンフェノール中に残存する未反応のホルムアルデヒドや、例えばレゾールの末端メチロール基に由来するホルムアルデヒドなど、骨格より遊離する可能性が否定できない。このホルムアルデヒドはシックハウス問題等で取りざたされている化学物質過敏症を引き起こす化合物として指摘を受けており、ホルムアルデヒドの遊離を抑えた樹脂の開発が要請されている。
【０００６】
ホルムアルデヒドの遊離を抑える手法としては、第１に、従来からあるホルムアルデヒドを含有する樹脂系に、ホルムアルデヒド捕捉能を有するいわゆるキャッチャーを添加する方法、第２に、ホルムアルデヒドを合成過程で使用しない樹脂を用いる方法とが考えられる。
【０００７】
しかしながら、前者は、インキ化したときの作業性の調整が困難であり、そもそも、末端メチロールに由来するホルムアルデヒドは経時的に遊離することが考えられ、キャッチャーのみで捕捉すること自体が難しい。
【０００８】
一方、後者のホルムアルデヒドを合成過程で使用しない樹脂についても、インキ用樹脂としての特性を満足する樹脂は限られており、ロジンを含有することが好ましい。ロジンを骨格に有し、架橋可能なものとして、重合ロジンが挙げられる。重合ロジンは、ロジンの加熱重合により得られた２塩基酸化合物であり、多価アルコールとのエステル化反応により高分子重合が可能となる。この樹脂は、「天然樹脂テレピン油・トール油」（Ｗ．サンダーマン著昭和６１年１２月２０日第２刷）に既に報告されている。
【０００９】
しかしながら、この重合ロジンと多価アルコールのエステル化反応により得られた樹脂をインキ用樹脂に適用する場合、インキ化する際に加える溶剤類と相溶性が非常に悪いという欠点を有する。これは、この重合ロジンエステル化反応物は、エステル結合を分子鎖中に多く含み、極性が非常に高く、一方インキ化する際に、添加される乾性油であるアマニ油や石油系溶剤とは、いずれも非極性であるために、この極性の違いから樹脂の溶解性が非常に悪いといった問題が発生する。
【００１０】
さらに、オフセット印刷では、水と油の反発を利用して、インキを版から紙等の支持体に転写させているために、水や油に対する適度な親和性が必要となる。具体的には、インキは浸し水と呼ばれる少量のイソプロピルアルコールを含む水にさらされる。したがって、水に対して親和性が良すぎると乳化しすぎて、樹脂が浸し水に溶けだしてしまういわゆるブリード現象が発生する。逆に、水との親和性が悪すぎると、インキの転写が起こらないといった問題が発生する。上述の重合ロジンエステル化反応物は、極性が強すぎるために、ブリード現象が発生しやすいといった問題が発生する。
【００１１】
【発明が解決しようとする課題】
本発明は、上記課題に鑑みなされたものであり、ホルムアルデヒドを全く含有しない樹脂であって、良好なオフセット印刷特性を有する新規な印刷インキ用樹脂を提供することにある。
【００１２】
【課題を解決するための手段】
本発明は、重合ロジン及びダイマー酸とを含む混合物に、該重合ロジン及び該ダイマー酸のカルボン酸１当量に対して、多価アルコールを０．５〜１．５当量の割合で加えてエステル化反応して得られた印刷インキ用樹脂に関する。
【００１３】
さらに本発明は、重合ロジンに重量比７％以下の不飽和カルボン酸、例えば、不飽和多塩基酸を添加し、付加反応して得られた変性重合ロジン及びダイマー酸とを含む混合物に、該変性重合ロジン及び該ダイマー酸のカルボン酸１当量に対して、多価アルコールを０．５〜１．５当量の割合で加えてエステル化反応して得られた印刷インキ用樹脂に関する。
【００１４】
さらに本発明は、重合ロジン１００重量部及びダイマー酸１〜２００重量部とを含む混合物に、該重合ロジン及び該ダイマー酸のカルボン酸１当量に対して、多価アルコールを０．５〜１．５当量の割合で加えてエステル化反応して得られた印刷インキ用樹脂に関する。
【００１５】
さらに本発明は、重合ロジンに重量比７％以下の不飽和カルボン酸、例えば、不飽和多塩基酸を添加し、付加反応して得られた変性重合ロジン１００重量部及びダイマー酸１〜２００重量部とを含む混合物に、該重合ロジン及び該ダイマー酸のカルボン酸１当量に対して、多価アルコールを０．５〜１．５当量の割合で加えてエステル化反応して得られた印刷インキ用樹脂に関する。
【００１６】
さらに本発明は、上記の印刷インキ用樹脂、乾性油、溶剤及び顔料を必須成分とする印刷用インキに関する。
【００１７】
本発明の印刷インキ用樹脂は、従来用いられていたモノカルボン酸であるロジンに替え、重合ロジンを用いているために、ホルムアルデヒドを遊離する可能性のあるフェノールによる変性を行わなくとも、架橋性を有する。
【００１８】
さらに、単に重合ロジンと多価アルコールとのエステル化反応により得られるエステル化反応物は、インキ樹脂としては極性が高すぎるが、重合ロジンとダイマー酸の混合物をエステル化することにより、エステル化反応物の樹脂骨格中に、長鎖アルキルがペンダント状に導入されるため、極性を最適にコントロールすることができる。
【００１９】
このような印刷インキ用樹脂は、従来になかったホルムアルデヒドフリーの樹脂でありながら、オフセット印刷特性、作業性を具備するといった長所を持つ。
【００２０】
【発明の実施の形態】
本発明で用いる重合ロジンとは、ロジンを重合して融点を高めたものをいい、通常、軟化点９０〜１４０℃、酸価は１４０〜１６０のものをいう。特に以下の化合物に限定されないが、例えば中国福建省の武平林化廠で製造される重合ロジン、中国桂林化工廠で製造される重合ロジン＃１１５、＃１３０、＃１４０、＃１５０、ブラジルＲＥＳＩＴＥＣ社製ＰＯＬＹＧＵＭＲＥＳＩＮ等が挙げられる。
【００２１】
また、重合ロジンに替え、重合ロジンに重量比７％以下の不飽和カルボン酸、例えば、不飽和多塩基酸を添加し、付加反応して得られた変性重合ロジンを用いることは、本発明において好ましい態様である。
【００２２】
不飽和カルボン酸、例えば、不飽和多塩基酸としては、アクリル酸、メタクリル酸等の不飽和モノカルボン酸、または、マレイン酸、無水マレイン酸、フマル酸、イタコン酸、無水イタコン酸及びケイ皮酸等の不飽和ジカルボン酸等が挙げられる。
【００２３】
変性重合ロジンは、重合ロジンが不飽和結合を有するため、不飽和カルボン酸、例えば、不飽和多塩基酸がエン反応またはディールズアルダー反応等の付加反応により付加することにより得られる。付加反応の条件としては、例えば、以下の条件をあげることができる。
【００２４】
２００℃で重合ロジンを溶融させて、不飽和カルボン酸、例えば、不飽和多塩基酸を一度に、または徐々に添加する。溶融後さらに、１時間程度温度を保持することにより、付加反応は完了する。
【００２５】
この付加反応の際に増量剤として、石油樹脂等を加えることは可能である。例えば、このような増量剤として、石油樹脂マルカレッツＴ２００Ａ（丸善石油化学（株）製）、クイントン１３２５（日本ゼオン（株）製）等を挙げることが出来る。
【００２６】
このように重合ロジンを不飽和カルボン酸、例えば、不飽和多塩基酸で変性することにより、樹脂が架橋構造をとりやすく、分子量が増大するためインキにしたときのインキ粘度が増加し作業性を向上することができる。
【００２７】
この付加反応する際に添加する不飽和カルボン酸、例えば、不飽和多塩基酸の重量を、重合ロジンに対して７重量％以下に限定したのは、７重量％を超えて添加した場合、後工程での多価アルコールとのエステル化反応時に、ゲル化する可能性があるためである。また、添加する不飽和カルボン酸、例えば、不飽和多塩基酸の重量は、１量％以上であることが好ましい。これは、不飽和カルボン酸、例えば、不飽和多塩基酸の変性による粘度の増粘効果を考慮した場合、１量％以上で実効的な効果が現れるためである。
【００２８】
ダイマー酸は、脂肪酸をクレーなどの触媒存在下で熱二量化させたものをいう。脂肪酸として、トール油、大豆油などの乾性油、半乾性油から得られたものが使用される。特に以下の化合物に限定されないが、ハリマ化成（株）製のハリダイマーＤＡ−２７０Ｓ、ＤＡ−２５０、ＤＡ−２００Ｋ等が挙げられる。
【００２９】
以下、印刷インキ用樹脂の調製方法について述べる。
【００３０】
重合ロジン１００重量部に対するダイマー酸の混合割合は、合成される印刷インキ用樹脂の溶剤等への相溶性を考慮すると、１重量部以上が好ましく、また、合成される印刷インキ用樹脂の軟化点を低すぎないように制御するためには、２００重量部以下であることが好ましい。
【００３１】
したがって、重合ロジン１００重量部、及び上記ダイマー酸１〜２００重量部さらに軟化点の向上を図るには、１〜５０重量部含む混合物に、多価アルコールを添加し、エステル化反応を行う。
【００３２】
多価アルコールの添加量は、上記混合物中の重合ロジン及びダイマー酸が有するカルボン酸１当量に対して、０．５〜１．５当量の割合で添加するのが好ましく、さらには０．８〜１．２当量の割合が好ましく、最も最適には０．９〜１．１当量が好ましい。
【００３３】
重合ロジンの替わりに変性重合ロジンを用いた場合も、重合ロジンの場合とまったく同じ理由により、変性重合ロジン１００重量部、及び上記ダイマー酸１〜２００重量部さらに軟化点の向上を図るには、１〜５０重量部含む混合物に、多価アルコールを添加し、エステル化反応を行う。
【００３４】
多価アルコールの添加量も重合ロジンの場合と全く同様に、上記混合物中の変性重合ロジン及びダイマー酸が有するカルボン酸１当量に対して、０．５〜１．５当量の割合で添加するのが好ましく、さらには０．８〜１．２当量の割合が好ましく、最も最適には０．９〜１．１当量が好ましい。
【００３５】
エステル化反応を行う際の触媒としては、酸化マグネシウム、酸化亜鉛、酸化カルシウム等を用いることができる。
【００３６】
また、反応温度については、２３０〜２９０℃が、適当であり、特に２５０〜２７０℃が最適である。この温度範囲における反応時間は、５〜１５時間で、好ましくは、７〜１０時間である。
【００３７】
重合ロジン（または変性重合ロジン）とダイマー酸との混合物に、エステル化反応時に発生する泡を消泡する目的で、シリコン系の消泡剤を添加することができる。
【００３８】
また、上記混合物に、０号ソルベント（日本石油化学（株）製）、ＡＦソルベント（日本石油化学（株）製）等の溶剤類、テレピン油等を適宜添加できる。これにより、反応終了時に樹脂を反応釜から取り出しやすくできる。
【００３９】
消泡剤や、溶剤等の上記添加剤については、エステル化反応時においても適宜添加することは可能である。
【００４０】
以上の合成反応により、本発明の印刷インキ用樹脂を調製できる。次にこの印刷インキ用樹脂を用いたインキについて説明を行う。
【００４１】
本願発明の印刷インキ用樹脂、乾性油、溶剤、顔料を配合することにより、インキを調製する。
【００４２】
乾性油は、例えば、アマニ油、桐油が挙げられる。また、半乾性油であるが大豆油等が挙げられる。これらは、ドライヤーと呼ばれる触媒によって、印刷後に乾性油どうしが重合し、皮膜が硬化する。
【００４３】
溶剤は、インキ粘度の調整と印刷後の乾燥性を早めるために添加され、例えば、０号ソルベント、０号ソルベントＳ、０号ソルベントＨ、ＡＦ４〜７号ソルベント（以上日本石油化学（株）製）等が挙げられる。
【００４４】
顔料は、被印刷物に色付けを行うためのでもので、必要に応じて、黄色、紅色、藍色または黒色等の顔料が選択される。
【００４５】
その他、インキにゲル味を持たせ、印刷特性を向上させる目的で、ゲル化剤を添加したり、印刷後の印刷光沢性を向上させる目的で、脂肪酸エステルを添加することは、本発明において好ましい態様である。
【００４６】
以下の実施例により、本発明をさらに詳細に説明する。
【００４７】
［実施例１］
反応容器中で、中国桂林化工廠の重合ロジン＃１４０（酸価１４８）５００ｇと石油樹脂Ｔ２００Ａ（丸善石油化学（株）製）６０ｇとを溶解し、さらに無水マレイン酸２０ｇを添加し、マレイン化を行い変性重合ロジンを調製した。
【００４８】
次いでこの反応容器中で、ダイマー酸（ハリダイマーＤＡ２００Ｋ：ハリマ化成（株）製）５０ｇを加え、変性重合ロジンとダイマー酸を混合し、この混合物に、多価アルコールとして、ペンタエリスリトール４６．６ｇ、グリセリン１７．６ｇを添加し、さらにエステル化触媒として酸化マグネシウム０．５ｇを添加した。さらにこの反応容器を２７０℃に加熱し、エステル化反応を行い、本発明の樹脂を得た。樹脂の特性を表１に示す。表１中の評価方法は、以下のように行った。
アマニ油粘度（ガードナー気泡型粘度）：アマニ油と上記樹脂を重量比２：１の割合で配合し、加熱溶解させたものをガードナー気泡型粘度計により測定した。ヘキサントレランス：アマニ油と上記樹脂を重量比２：１の割合で配合し、加熱溶解させたものにノルマルヘキサンを加え、白濁するのに要したヘキサン量の比率を測定した。
０号ソルベント溶解性：上記樹脂と０号ソルベントを溶解し２５℃にしたときに白濁しない最少量の樹脂の重量％を測定した。
重量平均分子量：ＧＰＣによるポリスチレン換算の分子量を測定した。
【００４９】
【表１】

ついで得られた樹脂を細かく砕き、この粉砕された樹脂４０重量部、アマニ油２０重量部、ＡＦ６号溶剤４０重量部を反応容器にいれ、窒素ガスを吹き込みながら昇温し、２００℃で撹拌しながら３０分保温しワニスを得た。得られたワニスを１００℃に冷却し、ゲル化剤を添加した。ゲル化剤は、ＡｌＣＨ（川研ファインケミカルス（株）製）１．４重量部を、ＡＦ６号溶剤１．４重量部で希釈したものを用いた。さらに、再度２００℃に昇温し、１時間保温しインキ用ゲルワニスを得た。
【００５０】
ついで、この得られたゲルワニス６０重量部と紅色顔料としてカーミン６Ｂ（東洋インキ製造（株）製）１８重量部を三本ロールミルを用いて分散し、ＡＦ６号溶剤とゲルワニスを総量１００重量部になるように添加し、ついで６％ナフテン酸マンガン溶液（ハリマ化成（株）製ドライヤー）を０．５重量部添加し、タックが５〜６、フローが３３〜３５になるように調整し、印刷用インキを得た。インキの特性を表２に示す。なお、表２には、実施例、比較例の各物性の測定結果とともに、各物性に対する最適な範囲についても掲載した。
【００５１】
表２に示す特性の評価方法は以下のように行った。
光沢値：インキ０．３ｃｃをＲＩテスター（（株）明製作所製）全面ロールでアート紙に展色したのち、２４時間後に光沢値を６０°−６０°光沢計で測定した。
【００５２】
セット：インキ０．１ｃｃをＲＩテスター（（株）明製作所製）４カットロールで展色したのち、展色物を切り、それを別のアート紙に貼り合わせ、ＲＩテスターのロールを用いて、インキがアート紙に付着しなくなるまでの時間（分）を測定した。通常の評価では、１２〜２１分が最適とされ、１２分より短いと、インキの保存性が悪いことが多く、２１分より長いと印刷物を重ねたときに、裏写りが発生しやすいことがわかっている。
紙上乾燥性：インキ０．１ｃｃをＲＩテスター（（株）明製作所製）４カットロールで硫酸紙に展色した後、硫酸紙を重ね合わせ、朝陽会式乾燥試験機にセットし０．１ｒｐｍの条件で乾燥時間を比較した。表２に示す評価基準は、以下の通りである。
◎：乾燥時間が、０以上４時間未満である。最も良好なレベルである。
○：乾燥時間が、４以上７時間未満である。良好なレベルである。
△：乾燥時間が、７以上１０時間未満である。普通のレベルである。
×：乾燥時間が、１０時間以上である。不適なレベルである。
インキ粘度及び降伏値：Ｌ型粘度計（東洋精機（株）製）により測定した。
フロー６０ｓ：離合社（株）のスプレッドメーターによるインキの広がり（直径）を測定した。
最大乳化量：リソドロニック乳化試験機（Novocontrol社製）を用いて、４０℃において、２５ｇのインキに２ｍｌ／分の速度で水を添加し、インキが飽和した時点の水分量を測定した。（乳化試験機の回転数：１２００ｒｐｍ）
【００５３】
【表２】

評価の結果、比較例４に示したフェノール変性ロジン（従来樹脂）を用いたインキと比較して、性能的には同等なインキが得られたことが判明した。
【００５４】
［実施例２］
実施例１と全く同様の条件で、変性重合ロジンを合成した。さらに、多価アルコールとして、ペンタエリスリトール６３．８ｇを加えた以外は、実施例１と全く同様な方法によりエステル化反応を行った。樹脂の特性を表１に示す。
【００５５】
さらに、この樹脂を用いて、実施例１と全く同様な方法によりインキを調製した。このインキの特性を表２に示す。
【００５６】
［実施例３］
反応容器中で、中国桂林化工廠の重合ロジン＃１４０（酸価１４８）５００ｇと石油樹脂Ｔ２００Ａ（丸善石油化学（株）製）６０ｇとを溶解した。
【００５７】
次いでこの反応容器中で、ダイマー酸（ハリダイマーＤＡ２００Ｋ：ハリマ化成（株）製）５５ｇを加え、重合ロジンとダイマー酸を混合し、この混合物に、多価アルコールとして、ペンタエリスリトール５３．１ｇを添加し、さらにエステル化触媒として酸化マグネシウム０．５ｇを添加した。さらにこの反応容器を２７０℃に加熱し、エステル化反応を行い、本願発明の樹脂を得た。樹脂の特性を表１に示す。
【００５８】
さらに、この樹脂を用いて、実施例１と全く同様な方法によりインキを調製した。このインキの特性を表２に示す。
【００５９】
［比較例１］
反応容器中で、中国桂林化工廠の重合ロジン＃１４０（酸価１４８）５００ｇと石油樹脂Ｔ２００Ａ（丸善石油化学（株）製）２０ｇとを溶解し、さらに無水マレイン酸１６．５ｇを添加し、マレイン化を行い変性重合ロジンを調製した。
【００６０】
次いでこの反応容器中で、多価アルコールとして、ペンタエリスリトール６８．７ｇを添加し、さらにエステル化触媒として酸化亜鉛０．１５ｇを添加した。さらにこの反応容器を２７０℃に加熱し、エステル化反応を行い、樹脂を得た。樹脂の特性を表１に示す。表１に示す。アマニ油粘度がＺ₁と低く、インキ化が不能であった。
【００６１】
［比較例２］
反応容器中で、中国桂林化工廠の重合ロジン＃１４０（酸価１４８）５００ｇと石油樹脂Ｔ２００Ａ（丸善石油化学（株）製）６０ｇとを溶解し、さらに無水マレイン酸４０ｇを添加し、マレイン化を行い変性重合ロジンを調製した。
【００６２】
次いでこの反応容器中で、ダイマー酸（ハリダイマーＤＡ２００Ｋ：ハリマ化成（株）製）５０ｇを加え、変性重合ロジンとダイマー酸を混合し、この混合物に、多価アルコールとして、ペンタエリスリトール６３．８ｇを添加し、さらにエステル化触媒として酸化亜鉛０．５ｇを添加した。さらにこの反応容器を２７０℃に加熱し、エステル化反応を行ったところ、無水マレイン酸が、多すぎたためにゲル化してしまった。
【００６３】
［比較例３］
反応容器中で、中国産ガムロジンＸグレード（酸価１７０）５００ｇと石油樹脂Ｔ２００Ａ（丸善石油化学（株）製）６０ｇとを溶解し、さらに無水マレイン酸２０ｇを添加し、マレイン化を行って、変性ガムロジンを調製した。
【００６４】
次いでこの反応容器中で、ダイマー酸（ハリダイマーＤＡ２００Ｋ：ハリマ化成（株）製）５０ｇを加え、前記変性ガムロジンとダイマー酸を混合した。この混合物に、多価アルコールとして、ペンタエリスリトール５０．８ｇ、グリセリン１９．２ｇを添加し、さらにエステル化触媒として酸化亜鉛０．５ｇを添加した。さらにこの反応容器を２７０℃に加熱し、エステル化反応を行い、樹脂を得た。
【００６５】
樹脂の特性を表１に示す。表１に示す。アマニ油粘度がＶ−Ｗと低く、インキ化が不能であった。
【００６６】
［比較例４］
印刷インキ用樹脂として、ロジンフェノール樹脂ハリフェノール１７３（ハリマ化成（株）製）を用いて、実施例１と全く同様な方法によりインキを調製した。このインキの特性を表２に示す。
【００６７】
【発明の効果】
本発明によれば、重合ロジンとダイマー酸の混合物をエステル化することにより、従来になかったホルムアルデヒドフリーの樹脂でありながら、オフセット印刷特性、作業性を具備する印刷インキ用樹脂を提供できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing ink resin having excellent ink performance and printing workability in offset printing, and a printing ink using the printing ink resin.
[0002]
[Prior art]
Offset printing is a typical printing method widely used for printing. This method includes a heat-set offset rotary printing method in which ink is dried by heat and a sheet-fed printing method in which drying oil is cured and dried using a catalyst. As a resin constituting the ink used for printing, a rosin phenol resin obtained by modifying a natural rosin with a phenol resin, particularly a resole resin is generally used.
[0003]
By having rosin in the resin skeleton, this rosin phenol resin has the advantage that the wettability with the pigment is improved and the pigment is easily dispersed uniformly. The reason that this rosin is modified with phenol is that rosin itself is a monocarboxylic acid that does not cause high-molecular polymerization, and therefore it is necessary to introduce a crosslinked structure.
[0004]
Furthermore, since phenol, formaldehyde, and an alkali or acid catalyst are used for the synthesis of the phenol resin, it can be said that formaldehyde is an essential component for the synthesis of the rosin phenol resin.
[0005]
However, in heat-set offset printing, a considerable amount of heat is applied to the printing ink. This heat causes unreacted formaldehyde remaining in the rosin phenol and formaldehyde derived from the terminal methylol group of resole, for example. The possibility of liberation cannot be denied. This formaldehyde has been pointed out as a compound causing chemical hypersensitivity, which has been addressed due to the sick house problem, and the development of a resin that suppresses the release of formaldehyde has been demanded.
[0006]
As a technique for suppressing the release of formaldehyde, first, a method of adding a so-called catcher having a formaldehyde scavenging ability to a conventional resin system containing formaldehyde, and second, a resin that does not use formaldehyde in the synthesis process is used. A method is considered.
[0007]
However, in the former, it is difficult to adjust the workability when it is converted into an ink. In the first place, formaldehyde derived from terminal methylol is considered to be released over time, and it is difficult to capture it with only a catcher.
[0008]
On the other hand, the resin that does not use the latter formaldehyde in the synthesis process is limited in resin that satisfies the characteristics as an ink resin, and preferably contains rosin. A polymerized rosin is mentioned as one having a rosin in the skeleton and capable of crosslinking. The polymerized rosin is a dibasic acid compound obtained by heat polymerization of rosin and can be polymerized by an esterification reaction with a polyhydric alcohol. This resin has already been reported in "Natural resin turpentine oil, tall oil" (W. Thunderman, second printing on December 20, 1986).
[0009]
However, when the resin obtained by the esterification reaction of the polymerized rosin and the polyhydric alcohol is applied to an ink resin, it has a drawback that it is very poorly compatible with the solvents to be added in the ink. This is because the polymerized rosin esterification reaction product contains many ester bonds in the molecular chain and has a very high polarity. On the other hand, it is different from the linseed oil and petroleum-based solvents that are added to the ink. Since both are non-polar, there arises a problem that the solubility of the resin is very poor due to the difference in polarity.
[0010]
Furthermore, in offset printing, ink and ink are transferred from a plate to a support such as paper by utilizing the repulsion of water and oil, so that a moderate affinity for water and oil is required. Specifically, the ink is exposed to water containing a small amount of isopropyl alcohol called soaking water. Therefore, if the affinity for water is too good, a so-called bleed phenomenon occurs in which the resin is so emulsified that the resin is soaked and dissolved in water. On the other hand, if the affinity with water is too bad, there arises a problem that ink transfer does not occur. Since the above-mentioned polymerized rosin esterification reaction product is too polar, there is a problem that a bleed phenomenon is likely to occur.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and is to provide a novel resin for printing ink which is a resin containing no formaldehyde and has good offset printing characteristics.
[0012]
[Means for Solving the Problems]
In the present invention, a polyhydric alcohol is added to a mixture containing a polymerized rosin and a dimer acid at a ratio of 0.5 to 1.5 equivalents per 1 equivalent of the carboxylic acid of the polymerized rosin and the dimer acid. The present invention relates to a resin for printing ink obtained by reaction.
[0013]
Further, the present invention relates to a mixture containing a modified polymerized rosin and a dimer acid obtained by adding an unsaturated carboxylic acid having a weight ratio of 7% or less to the polymerized rosin , for example, an unsaturated polybasic acid , and an addition reaction. The present invention relates to a resin for printing ink obtained by adding a polyhydric alcohol at a ratio of 0.5 to 1.5 equivalents with respect to 1 equivalent of a modified polymerization rosin and carboxylic acid of the dimer acid.
[0014]
Furthermore, the present invention provides a mixture containing 100 parts by weight of polymerized rosin and 1 to 200 parts by weight of dimer acid with respect to 0.5 equivalents of polyhydric alcohol to 1 equivalent of carboxylic acid of the polymerized rosin and dimer acid. The present invention relates to a resin for printing ink obtained by adding at a ratio of 5 equivalents and performing an esterification reaction.
[0015]
Furthermore, the present invention provides a polymerized rosin by adding an unsaturated carboxylic acid having a weight ratio of 7% or less , such as an unsaturated polybasic acid , and an addition reaction to obtain 100 parts by weight of a modified polymerized rosin and 1 to 200 parts by weight of a dimer acid. Printing ink obtained by adding a polyhydric alcohol at a ratio of 0.5 to 1.5 equivalents per 1 equivalent of the carboxylic acid of the polymerized rosin and the dimer acid to the mixture containing a part thereof It relates to resin.
[0016]
Furthermore, the present invention relates to a printing ink comprising the above printing ink resin, drying oil, solvent and pigment as essential components.
[0017]
The resin for printing ink of the present invention uses a polymerized rosin in place of the conventionally used monocarboxylic acid rosin, so that it does not require modification with phenol that may liberate formaldehyde. Have
[0018]
Furthermore, the esterification reaction product simply obtained by the esterification reaction of polymerized rosin and polyhydric alcohol is too polar as an ink resin, but by esterifying a mixture of polymerized rosin and dimer acid, the esterification reaction Since long-chain alkyl is introduced in a pendant form into the resin skeleton of the product, the polarity can be optimally controlled.
[0019]
Such a resin for printing ink has advantages such as offset printing characteristics and workability, although it is a formaldehyde-free resin that has not existed before.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The polymerized rosin used in the present invention refers to a polymer obtained by polymerizing rosin to increase the melting point, and generally refers to those having a softening point of 90 to 140 ° C. and an acid value of 140 to 160. Although not particularly limited to the following compounds, for example, polymerized rosin produced at Wuping Lin Chemicals in Fujian, China, polymerized rosin # 115, # 130, # 140, # 150 produced at Guilin Chemicals in China, Brazil RESITEC Examples include POLYGUMRESIN manufactured by the Company.
[0021]
Further, instead of polymerized rosin, polymerized rosin weight ratio of 7% or less of an unsaturated carboxylic acid, for example, the addition of unsaturated polybasic acids, the use of modified polymerized rosin obtained by addition reaction, in the present invention This is a preferred embodiment.
[0022]
Unsaturated carboxylic acids such as unsaturated polybasic acids include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, or maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride and cinnamic acid And the like, and the like.
[0023]
Since the polymerized rosin has an unsaturated bond, the modified polymerized rosin is obtained by adding an unsaturated carboxylic acid, for example, an unsaturated polybasic acid by an addition reaction such as an ene reaction or a Diels-Alder reaction. Examples of the conditions for the addition reaction include the following conditions.
[0024]
At 200 ° C., the polymerized rosin is melted and an unsaturated carboxylic acid, such as an unsaturated polybasic acid, is added in one portion or gradually. After the melting, the addition reaction is completed by maintaining the temperature for about 1 hour.
[0025]
In this addition reaction, it is possible to add petroleum resin or the like as an extender. Examples of such extenders include petroleum resin Marcaretz T200A (manufactured by Maruzen Petrochemical Co., Ltd.), quinton 1325 (manufactured by Nippon Zeon Co., Ltd.), and the like.
[0026]
Thus, by modifying the polymerized rosin with an unsaturated carboxylic acid, for example, an unsaturated polybasic acid , the resin can easily have a cross-linked structure, and the molecular weight increases. Can be improved.
[0027]
The weight of unsaturated carboxylic acid added during the addition reaction , for example, unsaturated polybasic acid , is limited to 7% by weight or less with respect to the polymerized rosin. This is because gelation may occur during the esterification reaction with the polyhydric alcohol in the process. Moreover, it is preferable that the weight of unsaturated carboxylic acid to add , for example, unsaturated polybasic acid , is 1 mass% or more. This is because an effective effect appears at 1% by weight or more in consideration of the effect of increasing the viscosity due to the modification of unsaturated carboxylic acid, for example, unsaturated polybasic acid .
[0028]
Dimer acid refers to a product obtained by heat dimerizing a fatty acid in the presence of a catalyst such as clay. As fatty acids, those obtained from dry oils such as tall oil and soybean oil, and semi-dry oils are used. Although not limited to the following compounds, Haridimer DA-270S, DA-250, DA-200K manufactured by Harima Kasei Co., Ltd. and the like can be mentioned.
[0029]
Hereinafter, a method for preparing a printing ink resin will be described.
[0030]
The mixing ratio of the dimer acid to 100 parts by weight of the polymerized rosin is preferably 1 part by weight or more in consideration of the compatibility of the synthesized printing ink resin with the solvent, etc. Also, the softening point of the synthesized printing ink resin Is preferably not more than 200 parts by weight so as not to be too low.
[0031]
Therefore, in order to improve the softening point of 100 parts by weight of polymerized rosin and 1 to 200 parts by weight of the dimer acid, a polyhydric alcohol is added to the mixture containing 1 to 50 parts by weight, and an esterification reaction is performed.
[0032]
The addition amount of the polyhydric alcohol is preferably 0.5 to 1.5 equivalents relative to 1 equivalent of the carboxylic acid contained in the polymerized rosin and dimer acid in the mixture, more preferably 0.8 to A ratio of 1.2 equivalents is preferred, most preferably 0.9 to 1.1 equivalents.
[0033]
In the case of using a modified polymerized rosin instead of the polymerized rosin, for the same reason as in the case of the polymerized rosin, 100 parts by weight of the modified polymerized rosin, and 1 to 200 parts by weight of the dimer acid, in order to further improve the softening point, A polyhydric alcohol is added to a mixture containing 1 to 50 parts by weight, and an esterification reaction is performed.
[0034]
The amount of polyhydric alcohol added is also 0.5 to 1.5 equivalents relative to 1 equivalent of the carboxylic acid of the modified polymerized rosin and dimer acid in the mixture, just as in the case of the polymerized rosin. The ratio is preferably 0.8 to 1.2 equivalents, and most preferably 0.9 to 1.1 equivalents.
[0035]
As a catalyst for performing the esterification reaction, magnesium oxide, zinc oxide, calcium oxide, or the like can be used.
[0036]
Moreover, about reaction temperature, 230-290 degreeC is suitable, and 250-270 degreeC is especially optimal. The reaction time in this temperature range is 5 to 15 hours, preferably 7 to 10 hours.
[0037]
A silicon-based antifoaming agent can be added to the mixture of the polymerized rosin (or modified polymerized rosin) and dimer acid for the purpose of defoaming bubbles generated during the esterification reaction.
[0038]
Moreover, solvents, such as No. 0 solvent (made by Nippon Petrochemical Co., Ltd.) and AF solvent (made by Nippon Petrochemical Co., Ltd.), turpentine oil, etc. can be added to the said mixture suitably. Thereby, the resin can be easily taken out from the reaction kettle at the end of the reaction.
[0039]
The above-mentioned additives such as an antifoaming agent and a solvent can be appropriately added even during the esterification reaction.
[0040]
The resin for printing ink of the present invention can be prepared by the above synthetic reaction. Next, the ink using this printing ink resin will be described.
[0041]
An ink is prepared by blending the printing ink resin, drying oil, solvent and pigment of the present invention.
[0042]
Examples of the dry oil include linseed oil and tung oil. Moreover, although it is a semi-drying oil, soybean oil etc. are mentioned. In these, a drying oil is polymerized after printing by a catalyst called a dryer, and the film is cured.
[0043]
The solvent is added to adjust the ink viscosity and accelerate the drying property after printing. For example, 0 Solvent, 0 Solvent S, 0 Solvent H, AF 4-7 Solvent (made by Nippon Petrochemical Co., Ltd.) ) And the like.
[0044]
Since the pigment is for coloring the printing material, a pigment such as yellow, red, indigo or black is selected as necessary.
[0045]
In addition, it is preferable in the present invention to add a gelling agent for the purpose of imparting a gel taste to the ink and improving printing characteristics, or to add a fatty acid ester for the purpose of improving printing gloss after printing. It is an aspect.
[0046]
The following examples illustrate the invention in more detail.
[0047]
[Example 1]
In a reaction vessel, 500 g of polymerized rosin # 140 (acid value 148) of China Guilin Chemical Industry Co., Ltd. and 60 g of petroleum resin T200A (manufactured by Maruzen Petrochemical Co., Ltd.) are dissolved, and 20 g of maleic anhydride is added to make malein. To prepare a modified polymerized rosin.
[0048]
Next, in this reaction vessel, 50 g of dimer acid (Haridimer DA200K: manufactured by Harima Kasei Co., Ltd.) is added, and the modified polymerized rosin and dimer acid are mixed. To this mixture, 46.6 g of pentaerythritol and glycerin are added as a polyhydric alcohol. 17.6 g was added, and 0.5 g of magnesium oxide was further added as an esterification catalyst. Further, this reaction vessel was heated to 270 ° C. to carry out esterification reaction to obtain the resin of the present invention. The properties of the resin are shown in Table 1. The evaluation methods in Table 1 were performed as follows.
Linseed oil viscosity (Gardner bubble type viscosity): Linseed oil and the above resin were blended at a ratio of 2: 1 by weight, and heated and dissolved, and measured with a Gardner bubble type viscometer. Hexane tolerance: Linseed oil and the above resin were blended at a ratio of 2: 1 by weight, and normal hexane was added to the mixture that was dissolved by heating, and the ratio of the amount of hexane required to become clouded was measured.
No. 0 solvent solubility: The above resin and No. 0 solvent were dissolved and the weight% of the minimum amount of resin that did not become cloudy when the temperature was 25 ° C. was measured.
Weight average molecular weight: The molecular weight in terms of polystyrene measured by GPC was measured.
[0049]
[Table 1]

Next, the obtained resin is finely crushed, and 40 parts by weight of the pulverized resin, 20 parts by weight of linseed oil, and 40 parts by weight of AF6 solvent are placed in a reaction vessel, heated while blowing nitrogen gas, and stirred at 200 ° C. While being kept warm for 30 minutes, a varnish was obtained. The obtained varnish was cooled to 100 ° C. and a gelling agent was added. As the gelling agent, 1.4 parts by weight of AlCH (manufactured by Kawaken Fine Chemicals Co., Ltd.) diluted with 1.4 parts by weight of AF6 solvent was used. Furthermore, the temperature was raised again to 200 ° C. and kept for 1 hour to obtain an ink gel varnish.
[0050]
Next, 60 parts by weight of the obtained gel varnish and 18 parts by weight of Carmine 6B (manufactured by Toyo Ink Co., Ltd.) as a red pigment are dispersed using a three-roll mill, and the total amount of AF6 solvent and gel varnish is 100 parts by weight. Next, 0.5 parts by weight of a 6% manganese naphthenate solution (Harima Kasei Co., Ltd. dryer) is added, and the tack is adjusted to 5 to 6 and the flow is adjusted to 33 to 35 for printing. An ink was obtained. Table 2 shows the ink characteristics. In Table 2, the measurement results of the physical properties of the examples and the comparative examples are listed along with the optimum ranges for the physical properties.
[0051]
The evaluation method of characteristics shown in Table 2 was performed as follows.
Gloss value: 0.3 cc of ink was developed on art paper with an RI tester (manufactured by Akira Seisakusho Co., Ltd.) and then the gloss value was measured with a 60 ° -60 ° gloss meter 24 hours later.
[0052]
Set: After 0.1 cc of ink is developed with a RI tester (manufactured by Mei Seisakusho Co., Ltd.) 4 cut rolls, the developed product is cut and pasted on another art paper, using the RI tester roll, The time (minutes) until the ink did not adhere to the art paper was measured. In a normal evaluation, 12 to 21 minutes is optimum, and if it is shorter than 12 minutes, the ink storage stability is often poor, and if it is longer than 21 minutes, show-through tends to occur when the printed materials are stacked. know.
Dryability on paper: After 0.1 cc of ink was developed on sulfuric acid paper with an RI tester (manufactured by Ming Seisakusho Co., Ltd.) 4 cut rolls, the sulfuric acid paper was overlaid and set in a Chaoyangkai drying tester. The drying time was compared under the conditions. The evaluation criteria shown in Table 2 are as follows.
A: Drying time is 0 or more and less than 4 hours. It is the best level.
○: Drying time is 4 or more and less than 7 hours. Good level.
Δ: Drying time is 7 or more and less than 10 hours. Normal level.
X: Drying time is 10 hours or more. Inadequate level.
Ink viscosity and yield value: Measured with an L-type viscometer (manufactured by Toyo Seiki Co., Ltd.).
Flow 60s: The spread (diameter) of the ink was measured using a spread meter manufactured by Koiso Co., Ltd.
Maximum emulsification amount: Using a lithodronic emulsification tester (manufactured by Novocontrol), water was added at a rate of 2 ml / min to 25 g of ink at 40 ° C., and the amount of water when the ink was saturated was measured. (Emulsification test machine rotation speed: 1200rpm)
[0053]
[Table 2]

As a result of the evaluation, it was found that an ink equivalent in performance was obtained as compared with the ink using the phenol-modified rosin (conventional resin) shown in Comparative Example 4.
[0054]
[Example 2]
A modified polymerized rosin was synthesized under exactly the same conditions as in Example 1. Furthermore, an esterification reaction was performed in the same manner as in Example 1 except that 63.8 g of pentaerythritol was added as a polyhydric alcohol. The properties of the resin are shown in Table 1.
[0055]
Further, an ink was prepared using this resin in the same manner as in Example 1. The properties of this ink are shown in Table 2.
[0056]
[Example 3]
In a reaction vessel, 500 g of polymerized rosin # 140 (acid value 148) from Guilin Chemical Industries, China and 60 g of petroleum resin T200A (manufactured by Maruzen Petrochemical Co., Ltd.) were dissolved.
[0057]
Next, 55 g of dimer acid (Haridimer DA200K: manufactured by Harima Chemicals Co., Ltd.) is added to the reaction vessel, and the polymerized rosin and dimer acid are mixed. To this mixture, 53.1 g of pentaerythritol is added as a polyhydric alcohol. Further, 0.5 g of magnesium oxide was added as an esterification catalyst. Further, this reaction vessel was heated to 270 ° C. to carry out esterification reaction to obtain a resin of the present invention. The properties of the resin are shown in Table 1.
[0058]
Further, an ink was prepared using this resin in the same manner as in Example 1. The properties of this ink are shown in Table 2.
[0059]
[Comparative Example 1]
In a reaction vessel, 500 g of polymerized rosin # 140 (acid value 148) of China Guilin Chemical Industry and 20 g of petroleum resin T200A (manufactured by Maruzen Petrochemical Co., Ltd.) are dissolved, and 16.5 g of maleic anhydride is further added. The modified polymerized rosin was prepared by maleating.
[0060]
Next, in this reaction vessel, 68.7 g of pentaerythritol was added as a polyhydric alcohol, and 0.15 g of zinc oxide was further added as an esterification catalyst. Further, this reaction vessel was heated to 270 ° C. to conduct esterification reaction to obtain a resin. The properties of the resin are shown in Table 1. Table 1 shows. Linseed oil viscosity was as low as Z ₁ , making it impossible to make ink.
[0061]
[Comparative Example 2]
In a reaction vessel, 500 g of polymerized rosin # 140 (acid value 148) of China Guilin Chemical Industry Co., Ltd. and 60 g of petroleum resin T200A (manufactured by Maruzen Petrochemical Co., Ltd.) are dissolved, and 40 g of maleic anhydride is added to make malein. To prepare a modified polymerized rosin.
[0062]
Next, in this reaction vessel, 50 g of dimer acid (Haridimer DA200K: manufactured by Harima Kasei Co., Ltd.) is added, the modified polymerized rosin and dimer acid are mixed, and 63.8 g of pentaerythritol is added as a polyhydric alcohol to this mixture. Further, 0.5 g of zinc oxide was added as an esterification catalyst. Furthermore, when this reaction vessel was heated to 270 ° C. and subjected to esterification reaction, gelation occurred because of too much maleic anhydride.
[0063]
[Comparative Example 3]
In a reaction vessel, 500 g of Chinese gum rosin X grade (acid number 170) and 60 g of petroleum resin T200A (manufactured by Maruzen Petrochemical Co., Ltd.) are dissolved, and 20 g of maleic anhydride is further added to perform maleation . Modified gum rosin was prepared.
[0064]
Next, 50 g of dimer acid (Haridimer DA200K: manufactured by Harima Kasei Co., Ltd.) was added to the reaction vessel, and the modified gum rosin and dimer acid were mixed. To this mixture, 50.8 g of pentaerythritol and 19.2 g of glycerin were added as a polyhydric alcohol, and 0.5 g of zinc oxide was further added as an esterification catalyst. Further, this reaction vessel was heated to 270 ° C. to conduct esterification reaction to obtain a resin.
[0065]
The properties of the resin are shown in Table 1. Table 1 shows. Linseed oil viscosity was as low as V-W, making it impossible to make ink.
[0066]
[Comparative Example 4]
Ink was prepared in exactly the same manner as in Example 1 using rosin phenol resin Hariphenol 173 (Harima Kasei Co., Ltd.) as the resin for printing ink. The properties of this ink are shown in Table 2.
[0067]
【The invention's effect】
According to the present invention, by esterifying a mixture of a polymerized rosin and a dimer acid, it is possible to provide a printing ink resin having offset printing characteristics and workability even though it is a formaldehyde-free resin that has never existed before.

Claims

Including carbon skeleton derived from polymerized rosin, carbon skeleton derived from dimer acid, and carbon skeleton derived from polyhydric alcohol,
The carbon skeleton derived from the polymerized rosin and the carbon skeleton derived from the polyhydric alcohol are linked by an ester bond,
The dimer acid-derived carbon skeleton and the polyhydric alcohol-derived carbon skeleton are linked by an ester bond,
A resin for printing ink having an ester bond in the molecular chain,
The printing ink resin has a weight average molecular weight of at least 14,000, and its acid value (mg / g) is 18.5 or less,
A resin prepared by an esterification reaction using the polymerized rosin, dimer acid, and polyhydric alcohol as raw materials,
The esterification reaction is
The polyhydric alcohol is added to the mixture of the polymerized rosin and dimer acid, heated to a reaction temperature selected in the range of 230 ° C. to 290 ° C., and in the presence of the esterification catalyst magnesium oxide for 7 hours to 10 hours. When performing the esterification reaction, the reaction time selected in the time range,
The mixture of polymerized rosin and dimer acid is a mixture containing 1 to 200 parts by weight of dimer acid per 100 parts by weight of polymerized rosin.
The carboxylic acid 1 equivalent of the mixture of the polymerized rosin and dimer acid, and the polyhydric alcohol was added in an amount of 0.5 to 1.5 equivalents of
A resin for printing inks.

Including a carbon skeleton derived from modified polymerized rosin, a carbon skeleton derived from dimer acid, and a carbon skeleton derived from polyhydric alcohol,
The carbon skeleton derived from the modified polymerized rosin and the carbon skeleton derived from the polyhydric alcohol are linked by an ester bond,
The dimer acid-derived carbon skeleton and the polyhydric alcohol-derived carbon skeleton are linked by an ester bond,
A resin for printing ink having an ester bond in the molecular chain,
The modified polymerized rosin is a modified polymerized rosin obtained by adding 1% to 7% of an unsaturated carboxylic acid in a weight ratio to the polymerized rosin and performing an addition reaction.
The printing ink resin has a weight average molecular weight of at least 110,000, and its acid value (mg / g) is 14.9 or less,
A resin prepared by an esterification reaction using the modified polymerized rosin, dimer acid, polyhydric alcohol as a raw material,
The esterification reaction is
The polyhydric alcohol is added to the mixture of the modified polymerized rosin and dimer acid, heated to a reaction temperature selected in the range of 230 ° C. to 290 ° C., and in the presence of magnesium oxide as an esterification catalyst for 7 hours to When performing the esterification reaction, the reaction time selected in the range of 10 hours,
The mixture of the modified polymerized rosin and the dimer acid is a mixture containing 1 to 200 parts by weight of the dimer acid per 100 parts by weight of the modified polymerized rosin.
Against the modified polymerized rosin and carboxylic acid 1 equivalent of the mixture of dimer acid, and the polyhydric alcohol was added in an amount of 0.5 to 1.5 equivalents of
A resin for printing inks.

Including carbon skeleton derived from polymerized rosin, carbon skeleton derived from dimer acid, and carbon skeleton derived from polyhydric alcohol,
The carbon skeleton derived from the polymerized rosin and the carbon skeleton derived from the polyhydric alcohol are linked by an ester bond,
The dimer acid-derived carbon skeleton and the polyhydric alcohol-derived carbon skeleton are linked by an ester bond,
A resin for printing ink having an ester bond in the molecular chain,
The printing ink resin has a weight average molecular weight of at least 14,000, and its acid value (mg / g) is 18.5 or less,
A resin prepared by an esterification reaction using the polymerized rosin, dimer acid, and polyhydric alcohol as raw materials,
The esterification reaction is
The polyhydric alcohol is added to the mixture of the polymerized rosin and dimer acid, heated to a reaction temperature selected in the range of 230 ° C. to 290 ° C., and in the presence of the esterification catalyst magnesium oxide for 7 hours to 10 hours. When performing the esterification reaction, the reaction time selected in the time range,
The mixture of polymerized rosin and dimer acid is a mixture containing 1 to 50 parts by weight of dimer acid per 100 parts by weight of polymerized rosin.
The carboxylic acid 1 equivalent of the mixture of the polymerized rosin and dimer acid, and the polyhydric alcohol was added in an amount of 0.5 to 1.5 equivalents of
A resin for printing inks.

Including a carbon skeleton derived from modified polymerized rosin, a carbon skeleton derived from dimer acid, and a carbon skeleton derived from polyhydric alcohol,
The carbon skeleton derived from the modified polymerized rosin and the carbon skeleton derived from the polyhydric alcohol are linked by an ester bond,
The dimer acid-derived carbon skeleton and the polyhydric alcohol-derived carbon skeleton are linked by an ester bond,
A resin for printing ink having an ester bond in the molecular chain,
The modified polymerized rosin is a modified polymerized rosin obtained by adding 1% to 7% of an unsaturated carboxylic acid in a weight ratio to the polymerized rosin and performing an addition reaction.
The printing ink resin has a weight average molecular weight of at least 110,000, and its acid value (mg / g) is 14.9 or less,
A resin prepared by an esterification reaction using the modified polymerized rosin, dimer acid, polyhydric alcohol as a raw material,
The esterification reaction is
The polyhydric alcohol is added to the mixture of the modified polymerized rosin and dimer acid, heated to a reaction temperature selected in the range of 230 ° C. to 290 ° C., and in the presence of magnesium oxide as an esterification catalyst for 7 hours to When performing the esterification reaction, the reaction time selected in the range of 10 hours,
The mixture of the modified polymerized rosin and the dimer acid is a mixture containing 1 to 50 parts by weight of the dimer acid per 100 parts by weight of the modified polymerized rosin.
The carboxylic acid 1 equivalent of the mixture of the modified polymer rosin and dimer acid, and the polyhydric alcohol was added in an amount of 0.5 to 1.5 equivalents of
A resin for printing inks.

The unsaturated carboxylic acid utilized in the preparation of the modified polymerized rosin is
The at least one unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride and cinnamic acid. Resin for printing inks as described in 2 or 4.

The polyhydric alcohol is
The printing ink according to claim 1, wherein the printing ink is at least one polyhydric alcohol selected from the group consisting of glycerin, trimethylolpropane, diethylene glycol, pentaerythritol, and dipentaerythritol. Resin .

It is a printing ink comprising as essential components a resin for printing ink, a drying oil, a solvent and a pigment,
The printing ink according to claim 1 , wherein the printing ink resin is a printing ink resin according to claim 1 .