JP4788935B2 - Acrylic polymer having a polymerizable unsaturated group at the molecular end - Google Patents

Description

（上記［Ｉ］式において、Ｍは、周期表４Ａ族、４Ｂ族、５Ａ族、５Ｂ族の金属、クロム、ルテニウム及びパラジウムよりなる群から選ばれる金属であり、Ｒ１およびＲ２は、それぞれ独立に、置換基を有することもある脂肪族炭化水素基、置換基を有することもある脂環式炭化水素基、置換基を有することもある芳香族炭化水素基および置換基を有することもあるケイ素含有基よりなる群から選ばれる少なくとも一種の基、若しくは、水素原子または単結合のいずれかであり、さらに、Ｒ１およびＲ２が共同して上記式［Ｉ］で表される化合物中の２個の５員環を結合していてもよく、また、複数の隣接するＲ１またはＲ２は、共同して環状構造を形成していてもよく、ａおよびｂは、それぞれ独立に、１〜５の整数であり、Ｘは水素原子の少なくとも一部がハロゲン原子で置換されていることもある炭化水素基またはハロゲン原子であり、ｎは０または金属Ｍの価数−２の整数である）
【００１６】
【発明の実施の形態】
以下に本発明による分子末端に重合性不飽和基を有することを特徴とするアクリル系重合体の実施の形態について説明する。
本発明によるこのアクリル系重合体は、不活性ガス雰囲気下に、重合開始剤として分子内にチオール基及び水酸基を有する化合物を用いて、（メタ）アクリル酸アルキルエステルを主成分とする重合性単量体を塊状重合させてなり、ＧＰＣによる数平均分子量が５００以上１００，０００以下であるアクリル系プレポリマーと、分子内にカルボキシル基及び重合性不飽和基を有する化合物とを反応させて得られる。
【００１７】
前記のアクリル系プレポリマーは、不活性ガス雰囲気下に、重合開始剤として分子内にチオール基及び水酸基を有する化合物を用いて、（メタ）アクリル酸アルキルエステルを主成分とする重合性単量体を塊状重合させて得られる。
【００１８】
この塊状重合の開始剤に用いる化合物は、分子内にチオール基及び水酸基を有している。具体的には、メルカプトメタノール、1-メルカプトエタノール、1-メルカプトプロパノール、1-メルカプト-2,3-プロパンジオール，1-メルカプト-2-ブタノール、1-メルカプト-2,3-ブタンジオール、1-メルカプト-3,4-ブタンジオール，1-メルカプト-3,4,4’-ブタントリオール、2-メルカプト-3-ブタノール、2-メルカプト-3,4-ブタンジオール、2-メルカプト-3,4,4’-ブタントリオール等を挙げることができる。
【００１９】
前記重合開始剤である分子内にチオール基及び水酸基を有する化合物は、後述するアクリル系単量体１００モルに対して、０．０１〜１００モル、好ましくは、０．１〜５０モル添加する。
【００２０】
また、前記重合開始剤である分子内にチオール基及び水酸基を有する化合物の重合開始剤効率を上げるために、次式［Ｉ］で表される有機金属化合物を重合系に添加することが好ましい。前記有機金属化合物は、重合開始剤である分子内にチオール基及び水酸基を有する化合物の分解触媒として作用する。
【化４】

ただし、上記式［Ｉ］において、Ｍは、周期表４Ａ族、４Ｂ族、５Ａ族、５Ｂ族の金属、クロム、ルテニウムおよびパラジウムよりなる群から選ばれる金属である。具体的にはＭは、チタン、ジルコニウム、クロム、ルテニウム、バナジウム、パラジウム、錫などである。また、式［Ｉ］において、Ｒ１およびＲ２は、それぞれ独立に、置換基を有することもある脂肪族炭化水素基、置換基を有することもある脂環族炭化水素基、置換基を有することもある芳香族炭化水素基、置換基を有することもあるケイ素含有基よりなる群から選ばれる少なくとも一種の基、水素原子または単結合のずれかであるさらに、Ｒ１およびＲ２が共同して該２個の５員環を結合していてもよく、また、複数の隣接するＲ１またはＲ２は、共同して環状構造を形成していてもよい。また、式［Ｉ］において、およびｂは、それぞれ独立に、１〜４の整数であり、Ｘは塩素、臭素、ヨウ素などのハロゲン原子または水素原子の少なくとも一部がハロゲン原子で置換されていることもある炭化水素基であり、ｎは０または金属Ｍの価数−２の整数である。このような有機金属化合物の例としては、ジシクロペンタジエン-Ｔｉ-ジクロライド、ジシクロペンタジエン-Ｔｉ-ビスフェニル、ジシクロペンタジエン-Ｔｉ-ビス-2,3,4,5,6- ペンタフルオロフェニ-1-イル、ジシクロペンタジエン-Ｔｉ-ビス-2,3,5,6- テトラフルオロフェニ-1-イル、ジシクロペンタジエン-Ｔｉ-ビス-2,5,6- トリフルオロフェニ-1-イル、ジシクロペンタジエン-Ｔｉ-ビス-2,6- ジフルオロフェニ-1-イル、ジシクロペンタジエン-Ｔｉ-ビス-2,4- ジフルオロフェニ-1-イル、ジメチルシクロペンタジエニル-Ｔｉ-ビス-2,3,4,5,6-ペンタフルオロフェニ-1-イル、ジメチルシクロペンタジエニル-Ｔｉ-ビス-2,3,5,6-テトラフルオロフェニ-1-イル、ジメチルシクロペンタジエニル-Ｔｉ-ビス-2,6-ジフルオロフェニ-1-イル、ジメチルシクロペンタジエニル-Ｔｉ-ビス-2,6-ジフルオロ-3-(ピル-1-イル)-フェニ-1-イルのようなチタノセン化合物；ジシクロペンタジエニル-Ｚｒ-ジクロライド、ジメチルシクロペンタジエニル-Ｚｒ-ジクロライドのようなジルコノセン化合物；及びルテノセン化合物、クロモノセン化合物などを挙げることができる。これらの有機金属化合物は単独であるいは組み合わせて使用することができる。
【００２１】
この有機金属化合物は、前記分子内にチオール基及び水酸基を有する化合物１００モルに対して、通常は０．１〜０．００００１モル、好ましくは０．０１〜０．０００１モルの量で使用される。０．００００１モル未満では、開始剤であるチオール基及び水酸基を有する化合物に対する触媒としての効果が低く、１．０モルを超えると、製造コストが高くなり好ましくない。
【００２２】
さらに、前記分子内にチオール基及び水酸基を有している化合物の中で、水酸基が２級水酸基である次式［II］で表される化合物は、単独での重合開始剤能が高く好ましい。
【化５】

但し、上記式［II］において、Ｒ３〜Ｒ７は、それぞれ独立に、水素原子又は炭素数１〜１２のアルキル基であり、Ｒ８は、水酸基、炭素数１〜１２のアルコキシ基及び炭素数１〜１２のアルキル基よりなる群から選ばれる少なくとも1つの基である。
【００２３】
前記アクリル系プレポリマーを調製するために使用するアクリル系単量体は、（メタ）アクリル酸アルキルエステルを主成分としている。（メタ）アクリル酸アルキルエステルの具体例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸ペンチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸-2-エチルヘキシル、（メタ）アクリル酸オクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸ドデシル等が挙げられる。
【００２４】
本発明で使用するアクリル系単量体は、（メタ）アクリル酸アルキルエステルの１種類の単量体でも良いが、２種類以上の単量体を組合わせても良い。更に、（メタ）アクリル酸アルキルエステルの以外の単量体を組合わせても良く、例えば以下に示す単量体を挙げることができる。
（メタ）アクリル酸および（メタ）アクリル酸アルカリ金属塩などの塩；
（メタ）アクリル酸フェニル、（メタ）アクリル酸ベンジルのような（メタ）アクリル酸アリールエステル；
（メタ）アクリル酸メトキシエチル、（メタ）アクリル酸エトキシエチル、（メタ）アクリル酸プロポキシエチル、（メタ）アクリル酸ブトキシエチル、（メタ）アクリル酸エトキシプロピルのような（メタ）アクリル酸アルコキシアルキル；
エチレングリコールのジ（メタ）アクリル酸エステル、ジエチレングリコールのジ（メタ）アクリル酸エステル、トリエチレングリコールのジ（メタ）アクリル酸エステル、ポリエチレングリコールのジ（メタ）アクリル酸エステル、プロピレングリコールのジ（メタ）アクリル酸エスエル、ジプロピレングリコールのジ（メタ）アクリル酸エスエル、トリプロピレングリコールのジ（メタ）アクリル酸エステルのような（ポリ）アルキレングリコールのジ（メタ）アクリル酸エステル；
（メタ）アクリロニトリル；酢酸ビニル；塩化ビニル；塩化ビニリデン；
（メタ）アクリル酸-2-クロロエチルのようなハロゲン化ビニル化合物；
（メタ）アクリル酸シクロヘキシルのような脂環式アルコールの（メタ）アクリル酸エステル；
2-ビニル-2-オキサゾリン、2-ビニル-5-メチル-2-オキサゾリン、2-イソプロペニル-2-オキサゾリンのようなオキサゾリン基含有重合性化合物；
（メタ）アクリロイルアジリジン、（メタ）アクリル酸-2-アジリジニルエチルのようなアジリジン基含有重合性化合物；
アリルグリシジルエーテル、（メタ）アクリル酸グリシジルエーテル、（メタ）アクリル酸-2-エチルグリシジルエーテルのようなエポキシ基含有ビニル単量体；
（メタ）アクリル酸-2-ヒドロキシエチル、（メタ）アクリル酸-3-ヒドロキシプロピル、（メタ）アクリル酸-2-ヒドロキシプロピル、（メタ）アクリル酸-4-ヒドロキシブチル、（メタ）アクリル酸ポリプロピレングリコールまたはポリエチレングリコールとのモノエステル、ラクトン類と（メタ）アクリル酸-2-ヒドロキシエチルとの付加物のようなヒドロキシル基含有ビニル化合物；
フッ素置換（メタ）アクリル酸アルキルエステル等の含フッ素ビニル単量体；
（メタ）アクリル酸を除く、イタコン酸、クロトン酸、マレイン酸、フマル酸のような不飽和カルボン酸、これらの塩並びにこれらの（部分）エステル化合物および酸無水物；
2-クロルエチルビニルエーテル、モノクロロ酢酸ビニルのような反応性ハロゲン含有ビニル単量体；
（メタ）アクリルアミド、Ｎ−メチロール（メタ）アクリルアミド、Ｎ−メトキシエチル（メタ）アクリルアミド、Ｎ−ブトキシメチル（メタ）アクリルアミドのようなアミド基含有ビニル単量体；
ビニルトリメトキシシラン、γ-メタクリロキシプロピルトリメトキシシラン、アリルトリメトキシシラン、トリメトキシシリルプロピルアリルアミン、2-メトキシエトキシトリメトキシシランのような有機ケイ素基含有ビニル化合物単量体；ならびに、
エチルデンノルボルネン、ピペリジン、イソプレン、ペンタジエン、ビニルシクロヘキセン、クロロプレン、ブタジエン、メチルブタジエン、シクロブタジエン、メチルブタジエンのようなジエン化合物。
が挙げられる。
【００２５】
さらに、トリメチロールプロパントリ（メタ）アクリル酸エステルのような多価（メタ）アクリル酸エステル、ジビニルベンゼン、エチレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ジメチロールトリシクロデカンジ（メタ）アクリレート、2,2-ビス［4-（（メタ）アクリロキシエトキシ）フェニル］プロパン等のような分子内に重合性不飽和基を２個以上有する単量体を組み合わせて、多分岐構造の重合体としても良い。
【００２６】
前記アクリル系プレポリマーは、不活性ガス雰囲気下に、重合開始剤として前記分子内にチオール基及び水酸基を有する化合物を用いて、前記（メタ）アクリル酸アルキルエステルを主成分とする重合性単量体を塊状重合させてえられるが、ＧＰＣによる数平均分子量が５００以上１００，０００以下である必要があり、５００〜１０，０００であることが好ましい。数平均分子量が５００未満であると、１分子中に含まれるアクリル骨格の含有率が低く、（メタ）アクリル骨格特有の性質が発現せず、前記化合物（ｂ）と反応させる際に、結晶性の増大のために析出現象を招いたり、前記化合物（ｂ）と反応させた後、前記化合物（ｃ）との反応させる場合において、その析出現象のために反応率の低下を招きやすい。さらに、数平均分子量が１００，０００を超えると、前記化合物（ｂ）、前記化合物（ｃ）との反応の際に、粘度の上昇及び流動性の低下等により作業性が低下すると共に、反応率の低下を引き起こしやすい。
【００２７】
本発明で使用する分子内にカルボキシル基及び重合性不飽和基を有する化合物の重合性不飽和基としては、（メタ）アクリロイル基、ビニル基、アリール基等であり、具体的な化合物としては、（メタ）アクリル酸、イタコン酸、クロトン酸、マレイン酸、フマル酸等が挙げられる。
【００２８】
本発明で使用する分子内にカルボキシル基及び重合性不飽和基を有する化合物は、前記アクリル系プレポリマー中のアクリル系プレポリマー中に存在する水酸基１００モルに対して、カルボキシル基が通常は１００〜１２０モル、好ましくは１０５〜１１５モルとなるような量で使用される。
【００２９】
前記アクリル系プレポリマーと前記分子内にカルボキシル基と重合性不飽和基を有する化合物との反応は、従来公知のエステル化反応を利用すれば良い。より具体的には、パラトルエンスルホン酸又は硫酸等の酸性触媒下、ベンゼン又はトルエン等の水と共沸して留去される有機溶媒の存在下で行う。エステル化終了後、中和、水洗、溶媒留去などを行うことにより、不純物を除去できる。
【００３０】
本発明の分子末端に重合性不飽和基を有するアクリル系重合体は、この重合体が粘稠な液体であり、重合性不飽和基を有することから、例えば、粘着剤、接着剤、塗料用ビヒクル、プライマー用樹脂、インキ用バインダー、セメントやモルタル、金属、ガラス等の無機材料表面の被覆コーティング樹脂、シート成形品（例；通気性シート、保護シート、遮水シート、制振シート、転写シート、調光シート、帯電防止シート、導電シート、養生シート、遮音シート、遮光シート、化粧シート、マーキングシート、難燃シート）、フィルム成形品（例；マーキングフィルム、保護フィルム、インキ定着フィルム、ラミネートフィルム）、発泡体（硬質発泡体、軟質発泡体、半硬質発泡体、難燃発泡体などを含む）、反応性可塑剤、可塑剤、希釈剤、相溶化剤、ＵＶ硬化型樹脂用のバインダー及び反応性希釈剤、ラジカル硬化シロップ型トラフィックペイント用バインダー樹脂及び希釈剤、中間原料として、ビニル系樹脂合成時のグラフト化剤やブロック化剤、ＮＢＲ、ＩＩＲ、ＳＢＲなどのゴム用変性剤及び架橋剤、改質剤用原料、マクロマーとしての各種ブロックポリマーなどの樹脂用原料または、改質用原料、添加剤、更には、繊維改質剤、繊維表面処理剤、紙加工剤、紙改質剤、界面活性剤、分散安定剤、分散媒、溶剤、粘度調整剤、吸着剤、毛髪処理剤、トナー用添加剤、帯電制御剤、帯電防止剤、低収縮剤、防曇剤、防汚剤、親水性付与剤、親油性付与剤、医薬担体、農薬用担体、化粧品用配合剤、滑剤、ポリマーアロイ用添加剤、ゲルコート剤、ＦＲＰ用樹脂、ＦＲＰ樹脂用添加剤、人工大理石用樹脂、人工大理石用樹脂添加剤、注入成型品用樹脂、ＵＶ・ＥＶ硬化樹脂用原料、粘着付与剤、各種バインダー（例；磁気記録媒体用バインダー、鋳造用バインダー、焼成体用バインダー、グラスファイバーサイジング材用バインダー）、ＲＩＭ用ウレタン改質剤、合わせガラス用樹脂、制振材、遮音材、分離膜用樹脂、防音材、吸音材、人工皮革、人工皮膚、合成皮革、各種工業用部品、日用品、トイレタリー用成型品、レジスト材用バインダー、レジスト材用添加剤、レジスト材用希釈剤、レジスト剤、フォトレジスト材用添加剤、希釈剤、バインダーその他、離型調整剤などで利用することが出来る。
【００３１】
【実施例】
以下に、実施例によって本発明をさらに詳細に説明するが、本発明は、これら実施例によって限定されるものではない。
【００３２】
アクリル系プレポリマーの製造
【製造例１】
撹拌装置、窒素導入管、温度計及び還流冷却管を備えたフラスコに、ブチルアクリレート９０重量部、2-ヒドロキシメチルメタクリレート１０重量部、およびルテノセンジクロライド０．１重量部を仕込みフラスコ内に窒素ガスを導入しながらフラスコの内容物を８０℃に加熱した。
【００３３】
ついで、十分に窒素ガス置換した2-メルカプトエタノール１０重量部を撹拌下にフラスコ内に添加した。フラスコ内の内容物の温度が８０℃に維持できるように、加熱及び冷却を４時間行った。さらに、十分に窒素ガス置換した2-メルカプトエタノール１０重量部を撹拌下のフラスコ内に追加添加した後、フラスコ内の内容物の温度が９０℃に維持できるように、さらに加熱及び冷却を行いながら、反応を４時間行った。
【００３４】
上記反応後、反応物の一部を採取して、ベンゾキノン溶液（９５％ＴＨＦ溶液）を添加し、モノマー残存率をガスクロマトグラフィーを用いて測定したところ、重合率は７８％であった。
【００３５】
つづいて得られた反応物に、ラジカル重合開始剤としてベンゾイルパーオキサイド０．１重量部を添加して未反応モノマーを重合させた後、反応物をエバポレーターに移し、減圧下に８０℃まで徐々に加熱しながら残存モノマー及び残存開始剤を除去した。
【００３６】
こうして得られたアクリル系プレポリマー（Ａ）の１５０℃加熱残分は９６．３％であった。また、得られたアクリル系プレポリマー（Ａ）についてゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定した分子量は、Ｍｗ＝９５０、Ｍｎ＝６５０、分散指数＝１．５であり、２３℃における粘度は、０．８５（Ｐａ・ｓ）であった。
【００３７】
【製造例２】
撹拌装置、窒素ガス導入管、温度計及び還流冷却管を備えたフラスコに、ブチルアクリレート１００重量部を仕込みフラスコ内に窒素ガスを導入しながらフラスコの空気を窒素ガスで置換した。さらに、窒素ガスを導入しながらフラスコの内容物を６０℃に加熱した。
【００３８】
ついで、重合開始剤として、十分に窒素ガス置換した1-メルカプト-2,3-プロパンジオール６重量部を攪拌下のフラスコ内に添加した。フラスコ内の内容物の温度が６０℃に維持できるように、加熱及び冷却を４時間行った。
【００３９】
上記反応後、反応物の一部を採取して、ベンゾキノン溶液（９５％ＴＨＦ溶液）を添加し、モノマー残存率をガスクロマトグラフィーを用いて測定したところ、重合率は７５％であった。
つづいて、得られた反応物をエバポレーターに移し、減圧下に８０℃まで徐々に加熱しながら残存モノマー及び残存開始剤を除去した。
【００４０】
こうして得られたアクリル系プレポリマー（Ｂ）の１５０℃加熱残分は９９．６％であった。また、得られたアクリル系プレポリマー（Ｂ）についてゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定した分子量は、Ｍｗ＝３４００、Ｍｎ＝１７００、分散指数＝２．０であり、２３℃における粘度は、２．６（Ｐａ・ｓ）であった。
【００４１】
【比較製造例１】
撹拌装置、窒素ガス導入管、温度計及び還流冷却管を備えたフラスコに、ブチルアクリレート９０重量部、及び、2-ヒドロキシメチルメタクリレート１０重量部を仕込み、フラスコ内に窒素ガスを導入しながらフラスコの内容物を８０℃に加熱した。
【００４２】
ついで、撹拌下に2-メルカプトエタノール１８重量部を添加し、つづいてラジカル重合開始剤として、アゾビスイソブチロニトリル０．１重量部及び2-メルカプトエタノール２重量部をフラスコ内に１時間かけて徐々に添加した。その添加後、フラスコ内の内容物の温度が８０℃に維持できるように、冷却及び加熱を行いながら、反応を７時間行った。
【００４３】
上記の反応を計８時間行った後、反応物の一部を採取して、ベンゾキノン溶液（９５％ＴＨＦ溶液）を添加し、モノマー残存率をガスクロマトグラフィーを用いて測定したところ、重合率は８７％であった。
つづいて、得られた反応物をエバポレーターに移し、減圧下に８０℃まで徐々に加熱しながら残存モノマー及び残存開始剤を除去した。
【００４４】
こうして得られたアクリル系プレポリマー（Ｃ−１）の１５０℃加熱残分は９６．３％であった。また、アクリル系プレポリマー（Ｃ−１）についてＧＰＣにより測定した分子量は、Ｍｗ＝９３０、Ｍｎ＝６１０、分散指数＝１．５であり、２３℃における粘度は、０．８０（Ｐａ・ｓ）であった。
【００４５】
【実施例１】
撹拌装置、乾燥窒素ガス導入管、温度計、モレキュラーシーブを装着した還流冷却管、滴下ロート及び分留コンデンサーを備えたフラスコに、製造例１で得られたアクリル系プレポリマー（Ａ）１００重量部、トルエン１０重量部、濃硫酸１重量部及びモノエチルヒドロキノン０．５重量部を仕込み、フラスコ内の空気を乾燥窒素ガスで置換しながら１００℃に加熱した。
【００４６】
つづいて、フラスコの内容物を１００℃に保ちながら、メタクリル酸２６重量部を２時間かけて滴下した。滴下終了後、減圧下に１００℃に保ち、トルエン及び縮合水を反応系外に共沸分留しながら、エステル化反応を行った。
【００４７】
エステル化反応終了後、フラスコの内容物を４０℃まで冷却し、３％炭酸ナトリウム水溶液で洗浄し、さらに水洗を２回行った。
ついで、フラスコの内容物をエバポレーターに移し、減圧下１００℃まで徐々に加熱しながら、残留水分及びトルエンを留去し、重合性不飽和基を分子末端に有するアクリル系重合体（１）を得た。
【００４８】
得られたアクリル系重合体（１）は、２３℃における粘度が０．５３（Ｐａ・ｓ）であった。
こうして得られたアクリル系重合体（１）中の残留水酸基をＦＴ−ＩＲ（フーリエ変換赤外吸収スペクトル）で調べたところ、水酸基に起因する吸収は完全に消失しており、アクリル酸に由来するアクリロイル基が観察された。
【００４９】
【実施例２】
アクリル系プレポリマー（Ａ）の代わりに、製造例２で得られたアクリル系プレポリマー（Ｂ）１００重量部を用いたこと以外は実施例１と同様にして、重合性不飽和基を分子末端に有するアクリル系重合体（２）を得た。
【００５０】
得られたアクリル系重合体（２）は、１５０℃における加熱残分が９９．８％であり、２３℃における粘度が１．２（Ｐａ・ｓ）であった。
こうして得られたアクリル系重合体（２）をＦＴ−ＩＲ（フーリエ変換赤外吸収スペクトル）で調べたところ、水酸基に起因する吸収は完全に消失しており、アクリル酸に由来するアクリロイル基が観察された。
【００５１】
【比較例１】
アクリル系プレポリマー（Ａ）の代わりに比較製造例１得られたアクリル系プレポリマー（Ｃ−１）を用いたこと以外は実施例１と同様にして、重合性不飽和基を分子末端に有するアクリル系重合体（３）を得た。
【００５２】
得られた重合性不飽和基を分子末端に有するアクリル系重合体（３）は、１５０℃における加熱残分が９９．４％であり、２３℃における粘度が０．４８（Ｐａ・ｓ）であった。
こうして得られたアクリル系重合体（３）をＦＴ−ＩＲ（フーリエ変換赤外吸収スペクトル）で調べたところ、水酸基に起因する吸収は完全に消失しており、アクリル酸に由来するアクリロイル基も観察された。
【００５３】
【参考例１】
容量２００ミリリットルのビーカーにアクリル系重合体（１）１００重量部と、開始剤として1,1,3,3-テトラメチルブチルパーオキシ-2-エチルヘキサノエート（商品名：パーオクタＯ、日本油脂（株）社製）０．１重量部を配合して、ビーカー内の内容物が均一になるまでミキサーにて十分に撹拌混合した。得られた配合物をポリエチレン製フィルム（膜厚５０μｍ）にバーコーダーを用いて、塗布厚５０μｍに塗布し、その上にポリエチレン製フィルム（膜厚５０μｍ）を被せた。これを１２０℃の乾燥機内にて６０分間放置させ、膜化物（１）を得た。
得られた膜化物（１）について、アセトン溶媒を用いたソックスレー抽出を行い、ゲル分率（％）を調べたところ８１％であった。
【００５４】
【参考例２】
参考例１において、アクリル系重合体（２）を使用したこと以外は同様にして、膜化物（２）を得た。得られた膜化物（２）のゲル分率を調べたところ８９％であった。
【００５５】
【比較参考例１】
参考例１において、アクリル系重合体（３）を使用したこと以外は同様にして、膜化物（３）を得た。得られた膜化物（３）のゲル分率を調べたところ４６％であり、膜化物（１）と比較するとかなり低い値を示した。
これは、アクリル系重合体（３）と比較してアクリル系重合体（１）の方が、１分子中に含まれる重合性不飽和基が多いことを意味している。
【００５６】
【発明の効果】
本発明の重合性不飽和基を分子末端に有するアクリル系重合体は、乳化剤又は分散剤などを含まず、分子末端に溶剤化合物残基やアゾ系及び過酸化物系などの従来公知の開始剤残基が無く、分子末端に確実に重合性不飽和基が導入されている。
【００５７】
また、本発明の重合性不飽和基を分子末端に有するアクリル系重合体は、無溶剤で粘調な液体として得られるプレポリマー使用することにより、そのプレポリマーに重合性不飽和基を導入する際に、必ずしも溶剤除去をする必要が無いため、分子末端が十分に制御された重合体となる。[0001]
[Technical field to which the invention belongs]
The present invention relates to an acrylic polymer having a polymerizable unsaturated group at a molecular end useful for paints, adhesives, molding materials and the like.
[0002]
[Prior art]
An oligomer or polymer having a polymerizable unsaturated group at the molecular end of a polymer obtained by polymerizing monomers is called a macromonomer, and is widely used in paints, adhesives, molding materials and the like. As a method for producing this macromonomer, ionic polymerization or radical polymerization is known. However, when the main chain structure of the macromonomer is mainly composed of an acrylic monomer, the functional group is usually terminated by radical polymerization. Is prepared by reacting a functional group with a reactive compound.
[0003]
More specifically, polymerization is performed using mercaptoacetic acid as an acrylic monomer, an azo initiator or a peroxide initiator, and a chain transfer agent to prepare a prepolymer having a carboxyl group at the molecular end, Polymerization using a method of reacting the carboxyl group with glycidyl methacrylate, an acrylic monomer, an azo initiator or a peroxide initiator, mercaptoethanol as a chain transfer agent, and a hydroxyl group-terminated prepolymer. There is a method of preparing a polymer and reacting the hydroxyl group with 2-isocyanatoethyl methacrylate.
[0004]
A method for preparing a prepolymer using a mercaptan having these functional groups as a chain transfer agent is usually carried out by solution polymerization. The polymerization temperature, the amount of radical polymerization initiator, an organic solvent or mercaptan as a radical chain transfer agent are used. By appropriately adjusting the amount used or the type of the polymer, the polymerization reaction such as polymerization rate and heat generation control, and polymer molecular design such as molecular weight and molecular weight distribution are performed. The molecular end of the polymer obtained by this method is bonded to a residue such as a compound used as a radical polymerization initiator, a compound used as a chain transfer agent, a solvent compound when chain transferred, or It has an unsaturated group when disproportionation is stopped. That is, the polymer obtained is not sufficiently controlled up to the end groups, and becomes a mixture of polymers having various end groups.
[0005]
For this reason, in these conventional methods for preparing a prepolymer, a molecule in which a polymerizable unsaturated group is not introduced is obtained, or a molecule in which a polymerizable unsaturated group is not introduced as designed is obtained. When such a macromonomer is used as a raw material for paints, adhesives, molding materials and the like, physical properties as designed are often not obtained.
[0006]
In addition, as a prepolymer preparation method, an aqueous radical polymerization method of emulsion polymerization and suspension polymerization is known. In the case of emulsion polymerization or suspension polymerization, separation from water as a dispersion medium is performed after polymerization of the prepolymer. Therefore, operations such as precipitation, filtration, washing, drying, and dissolution in a solvent for reacting a compound having reactivity with the functional group of the prepolymer are necessary, and the process becomes complicated.
[0007]
Furthermore, a bulk polymerization method is known as a prepolymer preparation method. The bulk polymerization method does not use a solvent and a dispersion medium, so there is no need to use an organic solvent, water, a dispersant, an emulsifier, etc., and it does not include impurities such as an organic solvent involved in the polymerization. In addition, impurities such as emulsifiers and dispersants are not mixed in the obtained polymer, and further, it is not necessary to remove the dispersion medium in order to obtain the desired prepolymer.
[0008]
However, in general, the bulk polymerization method has a remarkably high polymerization reaction rate, and it is practically very difficult to control the bulk polymerization method. In addition, the polymer produced at high temperature without controlling the polymerization rate, the end group of the molecule became unstable due to disproportionation termination, the molecular weight was reduced, or conversely produced earlier The polymer is likely to be branched or gelled due to hydrogen abstraction from the polymer. For this reason, it is difficult to design the molecular structure such as the molecular weight and molecular weight distribution of the polymer, and it is also difficult to design a clear molecular structure due to the branching of the polymer and the generation of disproportionation termination terminals. Furthermore, the gelled product may be generated rapidly and in a large amount, and in the worst case, the temperature rise of the reaction product cannot be suppressed and there is even a danger of explosion.
[0009]
Among acrylic monomers, methyl methacrylate has a characteristic that the polymerization rate is relatively slow. Therefore, reaction control is possible even by bulk polymerization, and its control method has been studied for a long time. In order to control the molecular weight and molecular weight distribution, mercaptans are used as chain transfer agents. For the polymerization initiation, addition of an azo polymerization initiator or a peroxide polymerization initiator, or thermal initiation polymerization at a high temperature is used. For this reason, in the polymer obtained by these reactions, a compound derived from a polymerization initiator is bonded to the polymer end or, in the case of thermal initiation polymerization, derived from a peroxide of a polymer monomer. A polymer in which a compound is bonded to the terminal is included, and the compound bonded to the terminal is not strictly controlled.
[0010]
Further, in the bulk polymerization reaction using such mercaptan, the mercaptan consumption rate during the polymerization and the consumption rate of the initiator are not equal, and the initiator remains in the reaction system even if the mercaptan is consumed during the polymerization. Therefore, it is often difficult to control the reaction uniformly, and there is a limit to the monomers used for bulk polymerization.
[0011]
For these reasons, a polymerization method, a polymerization catalyst, and a polymerization initiator for obtaining a polymer having a sufficiently controlled end are required.
[0012]
By the way, the catalyst for the polymerization reaction varies depending on the monomer used. For example, a metallocene compound such as titanocene is used as a polymerization catalyst such as ethylene, but this metallocene compound is used with a sensitizer in photopolymerization. For example, this metallocene compound is hardly known to be used as a polymerization catalyst for monomers other than α-olefins. JP-A-9-5996 includes a compound having at least one ethylenically unsaturated double bond capable of addition polymerization, a titanocene compound as a photopolymerization initiation system, and a sensitizer capable of sensitizing the titanocene compound. In the photopolymerizable composition, an invention of a photopolymerizable composition is disclosed in which the composition further contains a heterocyclic thiol compound. In the invention disclosed in this publication, the titanocene compound is used as a photopolymerization catalyst, and there is no description about using the titanocene compound as a bulk polymerization catalyst. Moreover, the heterocyclic thiol compound described in this publication is a visible light sensitizer.
[0013]
In general, in a metallocene compound such as a titanocene compound, a sulfur-containing compound is a compound that reduces the catalytic action of the metallocene compound, and as described above, a sulfur-containing compound that exhibits a specific effect such as a visible light sensitizer. The use of a compound is a very exceptional method of using a metallocene compound as a catalyst. That is, in general, a sulfur-containing compound is a compound that becomes a catalyst poison for a metallocene compound as a catalyst. Therefore, it is not preferable to add a sulfur compound to a reaction system using a metallocene compound as a catalyst. ing.
[0014]
[Problems to be solved by the invention]
The problem of the present invention is that it does not contain an emulsifier or a dispersant, has no conventionally known initiator residue such as a solvent compound residue or an azo group or a peroxide group at the molecular end, and ensures that the molecular end is not polymerizable. It is to provide an acrylic polymer that is a saturated group.
[Means for solving the problems]
The acrylic polymer having a polymerizable unsaturated group at the molecular end of the present invention comprises an acrylic prepolymer obtained by bulk polymerization using a compound having a thiol group and a hydroxyl group in the molecule as a polymerization initiator, It is obtained by reacting them with a compound having a carboxyl group and a polymerizable unsaturated group. When preparing an acrylic prepolymer, a compound having a thiol group and a hydroxyl group in the molecule is used as a polymerization initiator. Using a metal compound represented by the following formula [I] as a catalyst for the polymerization initiator, an initiator derived from a conventionally known azo initiator or peroxide type initiator at the molecular end of the polymer obtained Since it is bulk polymerization under a nitrogen atmosphere without having an agent residue, the polymer is colored or contains an emulsifier or dispersant in emulsion polymerization and suspension polymerization. No, never solvent compound residue in the solution polymerization is introduced into the molecular terminal.
[Chemical 3]

(In the above formula [I], M is a metal selected from the group consisting of 4A group, 4B group, 5A group, 5B group metal, chromium, ruthenium and palladium, and R1 and R2 are each independently An aliphatic hydrocarbon group that may have a substituent, an alicyclic hydrocarbon group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, and a silicon-containing group that may have a substituent At least one group selected from the group consisting of groups, or a hydrogen atom or a single bond, and R1 and R2 together represent two 5's in the compound represented by the above formula [I]. Member rings may be bonded, and a plurality of adjacent R 1 or R 2 may jointly form a cyclic structure, and a and b are each independently an integer of 1 to 5. , X is a hydrogen atom At least partially a hydrocarbon group or a halogen atom may have been substituted with a halogen atom, n represents a valence -2 integer of 0 or metal M)
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of an acrylic polymer having a polymerizable unsaturated group at the molecular end according to the present invention will be described below.
This acrylic polymer according to the present invention is a polymerizable monomer having a (meth) acrylic acid alkyl ester as a main component using a compound having a thiol group and a hydroxyl group in the molecule as a polymerization initiator in an inert gas atmosphere. It is obtained by reacting an acrylic prepolymer having a number average molecular weight of 500 or more and 100,000 or less by GPC with a compound having a carboxyl group and a polymerizable unsaturated group in the molecule. .
[0017]
The acrylic prepolymer is a polymerizable monomer mainly composed of (meth) acrylic acid alkyl ester using a compound having a thiol group and a hydroxyl group in the molecule as a polymerization initiator under an inert gas atmosphere. Obtained by bulk polymerization.
[0018]
The compound used as the bulk polymerization initiator has a thiol group and a hydroxyl group in the molecule. Specifically, mercaptomethanol, 1-mercaptoethanol, 1-mercaptopropanol, 1-mercapto-2,3-propanediol, 1-mercapto-2-butanol, 1-mercapto-2,3-butanediol, Mercapto-3,4-butanediol, 1-mercapto-3,4,4'-butanetriol, 2-mercapto-3-butanol, 2-mercapto-3,4-butanediol, 2-mercapto-3,4, 4'-butanetriol and the like can be mentioned.
[0019]
The compound having a thiol group and a hydroxyl group in the molecule as the polymerization initiator is added in an amount of 0.01 to 100 mol, preferably 0.1 to 50 mol, per 100 mol of an acrylic monomer described later.
[0020]
In order to increase the polymerization initiator efficiency of the compound having a thiol group and a hydroxyl group in the molecule as the polymerization initiator, it is preferable to add an organometallic compound represented by the following formula [I] to the polymerization system. The organometallic compound acts as a decomposition catalyst for a compound having a thiol group and a hydroxyl group in the molecule as a polymerization initiator.
[Formula 4]

In the above formula [I], M is a metal selected from the group consisting of metals of Group 4A, 4B, 5A, 5B, chromium, ruthenium and palladium of the periodic table . Specifically, M is titanium, zirconium, chromium, ruthenium, vanadium, palladium, tin or the like. In the formula [I], R1 and R2 each independently have an aliphatic hydrocarbon group that may have a substituent, an alicyclic hydrocarbon group that may have a substituent, or a substituent. A certain aromatic hydrocarbon group, at least one group selected from the group consisting of silicon-containing groups which may have a substituent, a hydrogen atom or a shift of a single bond; And a plurality of adjacent R 1 or R 2 may jointly form a cyclic structure. In Formula [I], and b are each independently an integer of 1 to 4, and X is a halogen atom such as chlorine, bromine or iodine, or at least a part of the hydrogen atom is substituted with a halogen atom. And n is an integer of 0 or a valence of metal M-2. Examples of such organometallic compounds include dicyclopentadiene-Ti-dichloride, dicyclopentadiene-Ti-bisphenyl, dicyclopentadiene-Ti-bis-2,3,4,5,6-pentafluoropheny- 1-yl, dicyclopentadiene-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, dicyclopentadiene-Ti-bis-2,5,6-trifluorophen-1-yl, Dicyclopentadiene-Ti-bis-2,6-difluorophen-1-yl, dicyclopentadiene-Ti-bis-2,4-difluorophen-1-yl, dimethylcyclopentadienyl-Ti-bis-2, 3,4,5,6-pentafluorophen-1-yl, dimethylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, dimethylcyclopentadienyl-Ti- Bis-2,6-difluorophen-1-yl, dimethylcyclopentadienyl-Ti-bi Titanocene compounds such as -2,6-difluoro-3- (pyr-1-yl) -phen-1-yl; such as dicyclopentadienyl-Zr-dichloride, dimethylcyclopentadienyl-Zr-dichloride And zirconocene compounds; and ruthenocene compounds and chromocenecene compounds. These organometallic compounds can be used alone or in combination.
[0021]
This organometallic compound is usually used in an amount of 0.1 to 0.00001 mol, preferably 0.01 to 0.0001 mol, per 100 mol of the compound having a thiol group and a hydroxyl group in the molecule. . If it is less than 0.00001 mol, the effect as a catalyst with respect to the compound which has a thiol group and a hydroxyl group which is an initiator is low, and when it exceeds 1.0 mol, manufacturing cost will become high and is not preferable.
[0022]
Furthermore, among the compounds having a thiol group and a hydroxyl group in the molecule, a compound represented by the following formula [II] in which the hydroxyl group is a secondary hydroxyl group is preferable because of its high ability of polymerization initiator alone.
[Chemical formula 5]

However, in said formula [II], R3-R7 is respectively independently a hydrogen atom or a C1-C12 alkyl group, R8 is a hydroxyl group, a C1-C12 alkoxy group, and C1-C1. It is at least one group selected from the group consisting of 12 alkyl groups.
[0023]
The acrylic monomer used to prepare the acrylic prepolymer has (meth) acrylic acid alkyl ester as a main component. Specific examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, (meth ) Hexyl acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and the like.
[0024]
The acrylic monomer used in the present invention may be one type of (meth) acrylic acid alkyl ester monomer, or two or more types of monomers may be combined. Furthermore, you may combine monomers other than (meth) acrylic-acid alkylester, for example, the monomer shown below can be mentioned.
Salts such as (meth) acrylic acid and alkali metal salts of (meth) acrylic acid;
(Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate;
Alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate;
Di (meth) acrylic acid ester of ethylene glycol, di (meth) acrylic acid ester of diethylene glycol, di (meth) acrylic acid ester of triethylene glycol, di (meth) acrylic acid ester of polyethylene glycol, di (meta) of propylene glycol ) Di (meth) acrylic acid esters of (poly) alkylene glycols, such as acrylic acid esters, dipropylene glycol di (meth) acrylates, tripropylene glycol di (meth) acrylates;
(Meth) acrylonitrile; vinyl acetate; vinyl chloride; vinylidene chloride;
Halogenated vinyl compounds such as (meth) acrylic acid-2-chloroethyl;
(Meth) acrylic acid esters of alicyclic alcohols such as (meth) acrylic acid cyclohexyl;
Oxazoline group-containing polymerizable compounds such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline;
Aziridine group-containing polymerizable compounds such as (meth) acryloylaziridine and (meth) acrylic acid-2-aziridinylethyl;
Epoxy group-containing vinyl monomers such as allyl glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid-2-ethylglycidyl ether;
(Meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-3-hydroxypropyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-4-hydroxybutyl, (meth) acrylic acid polypropylene Hydroxyl group-containing vinyl compounds such as monoesters with glycol or polyethylene glycol, adducts of lactones with 2-hydroxyethyl (meth) acrylate;
Fluorine-containing vinyl monomers such as fluorine-substituted (meth) acrylic acid alkyl esters;
Unsaturated carboxylic acids such as itaconic acid, crotonic acid, maleic acid, fumaric acid, their salts, and (partially) ester compounds and acid anhydrides, excluding (meth) acrylic acid;
Reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether and monochloro vinyl acetate;
Amide group-containing vinyl monomers such as (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide;
Organosilicon group-containing vinyl compound monomers such as vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxytrimethoxysilane; and
Diene compounds such as ethyldennorbornene, piperidine, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, methylbutadiene, cyclobutadiene, methylbutadiene.
Is mentioned.
[0025]
In addition, poly (meth) acrylates such as trimethylolpropane tri (meth) acrylate, divinylbenzene, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol tricyclodecandi Hyperbranched by combining monomers having two or more polymerizable unsaturated groups in the molecule such as (meth) acrylate, 2,2-bis [4-((meth) acryloxyethoxy) phenyl] propane A polymer having a structure may be used.
[0026]
The acrylic prepolymer is a polymerizable monomer comprising the (meth) acrylic acid alkyl ester as a main component using a compound having a thiol group and a hydroxyl group in the molecule as a polymerization initiator under an inert gas atmosphere. It can be obtained by bulk polymerization of the body, but the number average molecular weight by GPC needs to be 500 or more and 100,000 or less, and preferably 500 to 10,000. When the number average molecular weight is less than 500, the content of the acrylic skeleton contained in one molecule is low, the properties specific to the (meth) acrylic skeleton are not expressed, and crystallinity is caused when reacting with the compound (b). In the case of reacting with the compound (c) after the reaction with the compound (b) due to the increase in the reaction rate, the reaction rate tends to decrease due to the precipitation phenomenon. Furthermore, when the number average molecular weight exceeds 100,000, the workability is decreased due to an increase in viscosity and a decrease in fluidity during the reaction with the compound (b) and the compound (c), and the reaction rate. It is easy to cause decline.
[0027]
The polymerizable unsaturated group of the compound having a carboxyl group and a polymerizable unsaturated group in the molecule used in the present invention is a (meth) acryloyl group, a vinyl group, an aryl group, etc. (Meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid and the like can be mentioned.
[0028]
The compound having a carboxyl group and a polymerizable unsaturated group in the molecule used in the present invention usually has a carboxyl group of 100 to 100 mol per 100 mol of the hydroxyl group present in the acrylic prepolymer in the acrylic prepolymer. The amount used is 120 mol, preferably 105 to 115 mol.
[0029]
The reaction between the acrylic prepolymer and the compound having a carboxyl group and a polymerizable unsaturated group in the molecule may use a conventionally known esterification reaction. More specifically, it is carried out in the presence of an organic solvent distilled off azeotropically with water such as benzene or toluene under an acidic catalyst such as paratoluenesulfonic acid or sulfuric acid. After completion of esterification, impurities can be removed by neutralization, washing with water, distilling off the solvent, and the like.
[0030]
The acrylic polymer having a polymerizable unsaturated group at the molecular terminal of the present invention is a viscous liquid, and has a polymerizable unsaturated group. Vehicles, primer resins, ink binders, coated coating resins on the surface of inorganic materials such as cement, mortar, metal and glass, sheet molded products (eg, breathable sheets, protective sheets, water shielding sheets, vibration damping sheets, transfer sheets) , Light control sheet, antistatic sheet, conductive sheet, curing sheet, sound insulation sheet, light shielding sheet, decorative sheet, marking sheet, flame retardant sheet), film molded product (eg; marking film, protective film, ink fixing film, laminate film) ), Foams (including hard foams, soft foams, semi-rigid foams, flame retardant foams, etc.), reactive plasticizers, plasticizers, diluents Compatibilizers, binders and reactive diluents for UV curable resins, binder resins and diluents for radical curable syrup type traffic paints, intermediate materials, grafting agents and blocking agents for vinyl resin synthesis, NBR, IIR, SBR and other rubber modifiers and crosslinking agents, modifier raw materials, resin raw materials such as various block polymers as macromers, modifying raw materials, additives, fiber modifiers, fiber surfaces Treatment agent, paper processing agent, paper modifier, surfactant, dispersion stabilizer, dispersion medium, solvent, viscosity modifier, adsorbent, hair treatment agent, toner additive, charge control agent, antistatic agent, low Shrinking agent, antifogging agent, antifouling agent, hydrophilicity imparting agent, lipophilicity imparting agent, pharmaceutical carrier, agricultural chemical carrier, cosmetic compounding agent, lubricant, polymer alloy additive, gel coat agent, FRP resin, FRP resin Additive, Resin for artificial marble, Resin additive for artificial marble, Resin for injection molding product, Raw material for UV / EV curable resin, Tackifier, Various binders (Example: Binder for magnetic recording medium, Binder for casting, Fired body Binder, glass fiber sizing material binder), RIM urethane modifier, laminated glass resin, damping material, sound insulation material, separation membrane resin, soundproofing material, sound absorbing material, artificial leather, artificial skin, synthetic leather, Various industrial parts, daily necessities, molded products for toiletries, binders for resist materials, additives for resist materials, diluents for resist materials, resist agents, additives for photoresist materials, diluents, binders, release control agents, etc. Can be used.
[0031]
【Example】
EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
[0032]
Production of acrylic prepolymer [Production Example 1]
A flask equipped with a stirrer, a nitrogen introducing tube, a thermometer, and a reflux condenser is charged with 90 parts by weight of butyl acrylate, 10 parts by weight of 2-hydroxymethyl methacrylate, and 0.1 part by weight of ruthenocene dichloride, and nitrogen gas is introduced into the flask. The contents of the flask were heated to 80 ° C. while introducing.
[0033]
Subsequently, 10 parts by weight of 2-mercaptoethanol sufficiently substituted with nitrogen gas was added to the flask with stirring. Heating and cooling were performed for 4 hours so that the temperature of the contents in the flask could be maintained at 80 ° C. Furthermore, after adding 10 parts by weight of 2-mercaptoethanol sufficiently substituted with nitrogen gas to the stirred flask, while further heating and cooling so that the temperature of the contents in the flask can be maintained at 90 ° C. The reaction was carried out for 4 hours.
[0034]
After the reaction, a part of the reaction product was collected, a benzoquinone solution (95% THF solution) was added, and the residual monomer ratio was measured using gas chromatography. The polymerization rate was 78%.
[0035]
Subsequently, 0.1 part by weight of benzoyl peroxide as a radical polymerization initiator was added to the reaction product to polymerize the unreacted monomer, and then the reaction product was transferred to an evaporator and gradually reduced to 80 ° C. under reduced pressure. The residual monomer and residual initiator were removed while heating.
[0036]
The 150 ° C. heating residue of the acrylic prepolymer (A) thus obtained was 96.3%. Moreover, the molecular weights measured by gel permeation chromatography (GPC) for the obtained acrylic prepolymer (A) are Mw = 950, Mn = 650, dispersion index = 1.5, and the viscosity at 23 ° C. is It was 0.85 (Pa · s).
[0037]
[Production Example 2]
A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser was charged with 100 parts by weight of butyl acrylate, and the air in the flask was replaced with nitrogen gas while nitrogen gas was introduced into the flask. Further, the contents of the flask were heated to 60 ° C. while introducing nitrogen gas.
[0038]
Subsequently, 6 parts by weight of 1-mercapto-2,3-propanediol sufficiently substituted with nitrogen gas was added as a polymerization initiator into the stirred flask. Heating and cooling were performed for 4 hours so that the temperature of the contents in the flask could be maintained at 60 ° C.
[0039]
After the reaction, a part of the reaction product was collected, a benzoquinone solution (95% THF solution) was added, and the residual monomer ratio was measured using gas chromatography. The polymerization rate was 75%.
Subsequently, the obtained reaction product was transferred to an evaporator, and the residual monomer and the residual initiator were removed while gradually heating to 80 ° C. under reduced pressure.
[0040]
The 150 ° C. heating residue of the acrylic prepolymer (B) thus obtained was 99.6%. Moreover, the molecular weight measured by gel permeation chromatography (GPC) about the obtained acrylic prepolymer (B) is Mw = 3400, Mn = 1700, dispersion index = 2.0, and the viscosity at 23 ° C. is 2.6 (Pa · s).
[0041]
[Comparative Production Example 1]
A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 90 parts by weight of butyl acrylate and 10 parts by weight of 2-hydroxymethyl methacrylate, and while introducing nitrogen gas into the flask, The contents were heated to 80 ° C.
[0042]
Then, 18 parts by weight of 2-mercaptoethanol was added with stirring, and then 0.1 part by weight of azobisisobutyronitrile and 2 parts by weight of 2-mercaptoethanol were added to the flask as a radical polymerization initiator over 1 hour. Gradually added. After the addition, the reaction was carried out for 7 hours while cooling and heating so that the temperature of the contents in the flask could be maintained at 80 ° C.
[0043]
After performing the above reaction for a total of 8 hours, a part of the reaction product was collected, a benzoquinone solution (95% THF solution) was added, and the residual monomer ratio was measured using gas chromatography. 87%.
Subsequently, the obtained reaction product was transferred to an evaporator, and the residual monomer and the residual initiator were removed while gradually heating to 80 ° C. under reduced pressure.
[0044]
The acrylic prepolymer (C-1) thus obtained had a heating residue at 150 ° C. of 96.3%. The molecular weight of the acrylic prepolymer (C-1) measured by GPC is Mw = 930, Mn = 610, dispersion index = 1.5, and the viscosity at 23 ° C. is 0.80 (Pa · s). Met.
[0045]
[Example 1]
100 parts by weight of acrylic prepolymer (A) obtained in Production Example 1 in a flask equipped with a stirrer, a dry nitrogen gas introduction tube, a thermometer, a reflux condenser equipped with a molecular sieve, a dropping funnel and a fractionation condenser Then, 10 parts by weight of toluene, 1 part by weight of concentrated sulfuric acid and 0.5 parts by weight of monoethylhydroquinone were charged, and heated to 100 ° C. while replacing the air in the flask with dry nitrogen gas.
[0046]
Subsequently, 26 parts by weight of methacrylic acid was added dropwise over 2 hours while keeping the contents of the flask at 100 ° C. After completion of the dropping, the esterification reaction was carried out while maintaining the temperature at 100 ° C. under reduced pressure and azeotropically distilling toluene and condensed water out of the reaction system.
[0047]
After completion of the esterification reaction, the contents of the flask were cooled to 40 ° C., washed with a 3% aqueous sodium carbonate solution, and further washed twice with water.
Next, the contents of the flask are transferred to an evaporator, and while gradually heating to 100 ° C. under reduced pressure, residual moisture and toluene are distilled off to obtain an acrylic polymer (1) having a polymerizable unsaturated group at the molecular end. It was.
[0048]
The obtained acrylic polymer (1) had a viscosity at 23 ° C. of 0.53 (Pa · s).
When the residual hydroxyl group in the acrylic polymer (1) thus obtained was examined by FT-IR (Fourier transform infrared absorption spectrum), the absorption due to the hydroxyl group disappeared completely and originated from acrylic acid. An acryloyl group was observed.
[0049]
[Example 2]
Instead of the acrylic prepolymer (A), the polymerizable unsaturated group was terminated at the molecular end in the same manner as in Example 1 except that 100 parts by weight of the acrylic prepolymer (B) obtained in Production Example 2 was used. Acrylic polymer (2) was obtained.
[0050]
The obtained acrylic polymer (2) had a heating residue at 150 ° C. of 99.8% and a viscosity at 23 ° C. of 1.2 (Pa · s).
When the acrylic polymer (2) thus obtained was examined by FT-IR (Fourier transform infrared absorption spectrum), the absorption due to the hydroxyl group disappeared completely, and the acryloyl group derived from acrylic acid was observed. It was done.
[0051]
[Comparative Example 1]
It has a polymerizable unsaturated group at the molecular end in the same manner as in Example 1 except that the acrylic prepolymer (C-1) obtained in Comparative Production Example 1 was used instead of the acrylic prepolymer (A). An acrylic polymer (3) was obtained.
[0052]
The resulting acrylic polymer (3) having a polymerizable unsaturated group at the molecular end has a heating residue at 150 ° C. of 99.4% and a viscosity at 23 ° C. of 0.48 (Pa · s). there were.
When the acrylic polymer (3) thus obtained was examined by FT-IR (Fourier transform infrared absorption spectrum), the absorption due to the hydroxyl group disappeared completely, and the acryloyl group derived from acrylic acid was also observed. It was done.
[0053]
[Reference Example 1]
In a beaker with a capacity of 200 ml, 100 parts by weight of acrylic polymer (1) and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (trade name: Perocta O, Nippon Oil & Fats as initiator) 0.1 parts by weight) was mixed and sufficiently stirred and mixed with a mixer until the contents in the beaker were uniform. The resulting blend was applied to a polyethylene film (film thickness 50 μm) using a bar coder to a coating thickness of 50 μm, and a polyethylene film (film thickness 50 μm) was placed thereon. This was left to stand in a dryer at 120 ° C. for 60 minutes to obtain a film-formed product (1).
The obtained film-formed product (1) was subjected to Soxhlet extraction using an acetone solvent, and the gel fraction (%) was determined to be 81%.
[0054]
[Reference Example 2]
A filmed product (2) was obtained in the same manner as in Reference Example 1 except that the acrylic polymer (2) was used. When the gel fraction of the obtained film-formed product (2) was examined, it was 89%.
[0055]
[Comparative Reference Example 1]
A filmed product (3) was obtained in the same manner as in Reference Example 1 except that the acrylic polymer (3) was used. When the gel fraction of the filmed product (3) obtained was examined, it was 46%, which was considerably lower than that of the filmed product (1).
This means that the acrylic polymer (1) has more polymerizable unsaturated groups contained in one molecule than the acrylic polymer (3).
[0056]
【The invention's effect】
The acrylic polymer having a polymerizable unsaturated group at the molecular terminal of the present invention does not contain an emulsifier or a dispersant, and is a conventionally known initiator such as a solvent compound residue, azo-based or peroxide-based at the molecular terminal. There is no residue, and a polymerizable unsaturated group is reliably introduced at the molecular end.
[0057]
Moreover, the acrylic polymer which has a polymerizable unsaturated group of this invention in the molecular terminal introduce | transduces a polymerizable unsaturated group into the prepolymer by using the prepolymer obtained as a viscous liquid without a solvent. At this time, since it is not always necessary to remove the solvent, the polymer has a polymer whose molecular ends are sufficiently controlled.

Claims (3)

Under an inert gas atmosphere, in the molecule as a polymerization initiator have use a compound having a thiol group and a hydroxyl group,
Using a metal compound represented by the following formula [I] as a catalyst for the polymerization initiator,
An acrylic prepolymer having a number average molecular weight of 500 or more and 100,000 or less by GPC obtained by bulk polymerization of a polymerizable monomer having (meth) acrylic acid alkyl ester as a main component; An acrylic polymer having a polymerizable unsaturated group at a molecular end by reacting with a compound having a polymerizable unsaturated group.

In the above formula [I], M is a metal selected from the group consisting of 4A group, 4B group, 5A group, 5B group metal, chromium, ruthenium and palladium, and R1 and R2 are each independently An aliphatic hydrocarbon group that may have a substituent, an alicyclic hydrocarbon group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, and a silicon-containing group that may have a substituent And at least one group selected from the group consisting of a hydrogen atom or a single bond, and two of the five members in the compound represented by the above formula [I], wherein R1 and R2 are jointly represented A ring may be bonded, and a plurality of adjacent R1 or R2 may jointly form a cyclic structure, and a and b are each independently an integer of 1 to 5, X is a hydrogen atom Least part is a hydrocarbon group or a halogen atom may have been substituted with a halogen atom, n represents a valence -2 integer of 0 or metals M. The number of moles of the carboxyl group of the compound having a carboxyl group and a polymerizable unsaturated group in the molecule is 100 to 120 moles with respect to 100 moles of the hydroxyl group of the acrylic prepolymer. The acrylic polymer according to claim 1. The polymerization initiator is represented by the following formula [II]:

In the above [II] formula, R3 to R7 are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R8 is a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms. Is at least one group selected from the group consisting of alkyl groups,
The acrylic polymer according to claim 1 or 2, wherein