JP3645678B2

JP3645678B2 - Fluorine-containing copolymer

Info

Publication number: JP3645678B2
Application number: JP01013697A
Authority: JP
Inventors: 幸代木村; 光弘片山; 春夫閑
Original assignee: Kanto Denka Kyogyo Co.,Ltd.
Current assignee: Kanto Denka Kyogyo Co.,Ltd.
Priority date: 1997-01-23
Filing date: 1997-01-23
Publication date: 2005-05-11
Anticipated expiration: 2017-01-23
Also published as: JPH10204127A

Description

【０００１】
【発明の属する技術分野】
本発明は新規の含フッ素共重合体に関するものであり、さらに詳しくはフルオロオレフィン、シクロヘキシル基含有アクリル酸エステル、水酸基含有ビニルエーテルを必須の構成成分とする水酸基含有含フッ素共重合体の水酸基の一部と不飽和酸クロライドを反応させることを特徴とした、硬質で接着性、耐汚染性、耐薬品性、耐候性に優れた新規二重結合含有含フッ素共重合体に関するものである。
【０００２】
【従来の技術】
ヒドロキシアルキル基を含むフルオロオレフィン共重合体は例えばヒドロキシアルキルビニルエーテルとフルオロオレフィンと必要に応じてアルキルビニルエーテル、アルキルビニルエステル等を共重合して得られ、常温硬化型塗料用ベースとして用いられている。
【０００３】
かかるフルオロオレフィン共重合体をベースとする常温硬化型塗料は、耐薬品性、耐候性、耐汚染性、耐熱性などに優れているが、塗布する直前に硬化剤を混合する必要がある。これは、作業上簡便ではなく、可使時間にも注意を払う必要がある。
【０００４】
【発明が解決しようとする課題】
すなわち、本発明の目的は、硬化剤を使用せず、光あるいは熱で短時間で硬化可能な硬質で接着性、耐汚染性、耐薬品性、耐候性に優れた新規二重結合含有含フッ素共重合体とその製造法を提供することにある。
【０００５】
【発明を解決するための手段】
本発明者等は前記の好ましい性質を有する含フッ素共重合体を開発すべく鋭意研究を重ねた結果、水酸基含有含フッ素共重合体の水酸基の一部と不飽和酸クロライドとの脱塩酸反応によって、含フッ素共重合体中に二重結合を導入することにより上記課題を解決できる事を見出し、本発明を完成する至った。
【０００６】
すなわち、本発明は、フルオロオレフィン、シクロヘキシル基含有アクリル酸エステル、水酸基含有ビニルエーテルを必須の構成成分とする水酸基含有含フッ共重合体の一部を不飽和酸クロライドと反応させることを特徴とした、硬質で、接着性、耐汚染性、耐薬品性、耐候性に優れた新規二重結合含有含フッ素共重合体に関するものである。
【０００７】
すなわち、本発明は、
（Ａ）フッ化ビニリデン、テトラフルオロエチレン、又はそれらの組み合わせであるフルオロオレフィン４０〜９０モル％
（Ｂ）一般式
【化４】

（式中、Ｒ¹は水素またはメチル基である）
で表される（メタ）アクリル酸シクロヘキシルエステル１〜３０モル％、及び
（Ｃ）一般式
【化５】

（式中、Ｒ²は炭素数２〜５のアルキレン基、又はシクロヘキシル基を示す）
で表される水酸基含有ビニルエーテル１〜３０モル％を必須の構成成分とする水酸基含有含フッ素共重合体の水酸基の一部を不飽和酸クロライドと反応させることにより製造され、硬質で、接着性、耐汚染性、耐薬品性、耐候性、耐熱性などに優れた塗料塗膜を与える、数平均分子量１，０００〜５０，０００の新規二重結合含有含フッ素共重合体を提供するものである。
【０００８】
本発明の共重合体において、（Ａ）単位を形成するフルオロオレフィンは分子中に少なくとも２個のフッ素原子を有するオレフィンであって、フッ化ビニリデン、テトラフルオロエチレン等が好適である。これらのフルオロオレフィンは、それぞれ単独で用いてもよいし、２種以上を組み合わせて用いてもよい。
【０００９】
本発明の共重合体において、（Ｂ）単位を形成する単量体は前記の一般式で表される。このような単量体の好ましい具体例としては、例えばシクロヘキシルアクリレート、シクロヘキシルメタクリレート等を挙げることが出来るが、シクロヘキシルメタクリレートが特に好ましい。
【００１０】
本発明の共重合体において、（Ｃ）単位を形成する水酸基含有ビニルエーテルの具体例としては、ヒドロキシメチルビニルエーテル、ヒドロキシエチルビニルエーテル、ヒドロキシプロピルビニルエーテル、ヒドロキシブチルビニルエーテル、エチレングリコールモノアリルエーテル、シクロヘキシルビニルエーテル等が挙げられるが、特にヒドロキシブチルビニルエーテル、ヒドロキシエチルビニルエーテル、シクロヘキシルビニルエーテルが好適である。これらの水酸基含有ビニルエーテルはそれぞれ単独で用いてもよいし、２種以上を組み合わせて用いてもよい。
【００１１】
本発明の共重合体において、不飽和酸クロライドの具体例としては、アクリル酸クロライド、メタクリル酸クロライド、桂皮酸クロライド、クロトン酸クロライド、オレイン酸クロライド、チグリン酸クロライド等が挙げられる。
【００１２】
本発明の共重合体は、硬質で接着性、耐汚染性、耐薬品性、耐候性、耐熱性などに優れた塗膜を形成することができるが、使用目的などに応じて２０モル％を越えない範囲で他の共重合可能な単量体単位を含むこともできる。該共重合可能な単量体としては、例えばエチルビニルエーテル、ブチルビニルエーテル、シクロヘキシルビニルエーテル等のアルキルビニルエーテル類やエチレン、プロピレン等のオレフィン類、塩化ビニール、塩化ビニリデン等のハロオレフィン類、酢酸ビニール、ｎ−酪酸ビニール、バーサチック酸ビニール、等のカルボン酸ビニールエステル類等が挙げられる。
【００１３】
本発明の共重合体は、フルオロオレフィンに基づく重合単位（Ａ）を４０〜９０モル％、アクリル酸シクロヘキシルエステル又はメタクリル酸シクロヘキシルエステルに基づく重合単位（Ｂ）を１〜３０モル％、ヒドロキシル基を有する重合単位（Ｃ）を１〜３０モル％の割合で含有する水酸基含有含フッ素共重合体に不飽和酸クロライド１〜３０モル％反応させて得られる。
【００１４】
重合単位（Ａ）の割合が４０モル％より少ない場合には、塗料ベースとして使用した場合に、十分な耐汚染性、耐薬品性、耐候性が得られず好ましくない。また９０モル％より多い場合には各種溶剤に対する溶解性が低下し、塗料ベースとしての使用が困難になる。
【００１５】
重合単位（Ｂ）の割合が上記より少ないと、樹脂溶液の保存安定性が低下し、また硬化塗膜の耐溶剤性、耐薬品性が低下し好ましくなく、上記より多い場合には重合時における重合速度が低下し好ましくない。
【００１６】
重合単位（Ｃ）の割合が上記より少ないと、硬化反応が起こりにくくなり、硬化塗膜の耐溶剤性、耐薬品性が低下し好ましくなく、上記より多い場合には共重合が困難となり、好ましくない。
【００１７】
本発明の共重合体は、溶媒の存在下または不存在下で、所定割合の単量体混合物を、重合開始剤を用い共重合させることにより製造することができる。
【００１８】
該重合開始剤としては、重合形式や所望に応じて用いられる溶媒の種類に応じて、水溶性のものあるいは油溶性のものが適宜用いられる。
【００１９】
水溶性重合開始剤としては、例えば過硫酸カリウム等の過硫酸塩、過酸化水素、あるいはこれらと亜硫酸水素ナトリウム、チオ硫酸ナトリウムなどの還元剤との組み合わせからなるレドックス還元剤、さらには、これらに少量の鉄、第一鉄塩、硝酸銀等を共存させた無機系開始剤やコハク酸パーオキサイド、ジグルタル酸パーオキサイド、モノコハク酸パーオキサイドなどの二塩基酸塩などの有機系開始剤が用いられる。
【００２０】
また油溶性開始剤としては、例えばｔ−ブチルパーオキシイソブチレート、ｔ−ブチルパーオキシアセテート等のパーオキシエステル型過酸化物、ジイソプロピルパーオキシジカーボネート、ジノルマルプロピルパーオキシジカーボネート等のジアルキルパーオキシジカーボネート、ベンゾイルパーオキサイド、アゾビスイソブチロニトリル等が用いられる。
【００２１】
これらの重合開始剤の使用量は、その種類、共重合反応条件などに応じて適宜選ばれるが、単量体全量に対して、０．００５〜５重量％、好ましくは０．１〜１％の範囲で選ばれる。
【００２２】
また、重合方法については特に制限はなく、例えば塊状重合法、懸濁重合法、乳化重合法、溶液重合法等を用いることが出来るが、メチルエチルケトン等のケトン類、酢酸エチル等のエステル類、フッ素原子１個以上有する飽和ハロゲン化炭化水素類等を溶媒とする溶液重合法や水性媒体中での乳化重合法等が好ましく用いられる。
【００２３】
水性媒体中で共重合させる場合には、通常分散安定剤として懸濁剤や乳化剤を用い、かつ塩基性緩衝剤を添加して、重合中の反応液のｐＨ値を４以上、好ましくは６以上にする事が望ましい。
【００２４】
該共重合反応における反応温度は、通常−３０℃〜１５０℃での範囲内で重合開始剤や重合媒体の種類に応じて適宜選ばれ、例えば水性媒体中で共重合を行う場合には、通常０〜１００℃、好ましくは１０〜９０℃の範囲で選ばれる。また、反応圧力については特に制限はないが、通常１〜１００ｋｇ／ｃｍ²、好ましくは１〜６０ｋｇ／ｃｍ²の範囲で選ばれる。さらに、該共重合反応は、適当な連鎖移動剤を添加して行う事ができる。
【００２５】
このようにして得られた共重合体と酸クロライドとの反応に際しては、反応によって副生する塩酸の固定剤として反応系中にピリジンやトリエチルアミン等の第三級アミンを加えることが効果的である。
【００２６】
共重合体と酸クロライドとの反応における温度は、通常１０℃〜１３０℃、好ましくは２５℃〜８５℃の範囲で選ばれる。
【００２７】
かかる方法により得られた二重結合含有含フッ素共重合体は、光あるいは熱によって硬化が可能である。
【００２８】
光硬化開始剤としては、ベンゾインエーテル、ベンゾフェノン、１−ヒドロキシ−シクロヘキシルフェニルケトン、２−メチル−１−［４−（メチルチオ）フェニル］−２−モンフォリノプロパン−１、２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタノン−１、２，２−ジメトキシ−１，２−ジフェニルエタン−１−オン等が用いられる。
【００２９】
また熱硬化開始剤としては、ベンゾイルパーオキサイド、アゾビスイソブチロニトリル、ｔ−ブチルパーオキシ−２−エチルヘキサネート、ｔ−ブチルパーオキシイソプロピルモノカーボネート等が用いられる。
【００３０】
【実施例】
次に、実施例により本発明をさらに詳細に説明するが、本発明はこれらの例によってなんら限定されるものではない。
【００３１】
なお、本発明の共重合体の分子量は、溶媒に酢酸エチル、標準物質としてポリスチレンを用い、ゲルバミレーションクロマトグラフ（ＧＰＣ）法により測定した。
【００３２】
本発明の中間共重合体である水酸基含有含フッ素共重合体及び、最終共重合体である二重結合含有含フッ素共重合体の同定は赤外線吸収スペクトル（ＩＲ）を用いて行った。
【００３３】
含フッ素共重合体の水酸基価はＪＩＳＫ００７０に準じて測定した。
【００３４】
（実施例１）
内容積１Ｌのステンレス製撹拌機付きオートクレーブ（耐圧１００ｋｇ／ｃｍ²）に、脱気したのち、フッ化ビニリデン（以下ＶＤＦと略す）１１５．３ｇ、テトラフルオロエチレン（以下ＴＦＥと略す）８４．４ｇ、シクロヘキシルメタクリレート（以下ＣＨＭＡと略す）２５．３ｇ、４−ヒドロキシブチルビニルエーテル（以下ＨＢＶＥと略す）２４．５ｇ、酢酸エチル４００ｍｌ、およびｔ−ブチルパーオキシピバレート（日本油脂（株）製品「パーブチルＰＶ」）１．２５ｇを入れ、撹拌しながら内温を６０℃に昇温した。２０時間後撹拌を停止し、未反応モノマーを放気して反応を停止させた。オートクレーブを開放して反応液を取り出し、固形分濃度３０％、樹脂分水酸基価＝５０ｍｇ−ＫＯＨ／ｇ（以下同単位）、数平均分子量≒３５，０００の水酸基含有含フッ素共重合体溶液を得た。これを［共重合体Ａ］とする。図１に［共重合体Ａ］の乾燥塗膜の赤外線吸収スペクトル（ＩＲ）チャートを示す。３２００ｃｍ−１付近に水酸基の吸収ピーク（図中矢印で示す）が確認される。
【００３５】
暗所中で撹拌機、還流コンデンサー、滴下漏斗、塩化カルシウム塔をつけた５００ｃｃ丸底三つ口フラスコに［共重合体Ａ］２００ｇおよびピリジン３．５ｇを仕込んだ。一方滴下漏斗に桂皮酸クロライド７．４ｇ、酢酸エチル１７．２ｇを仕込む。温度を５０℃に保ち撹拌しながら桂皮酸クロライドの酢酸エチル溶液を少しずつ滴下する。滴下終了後、５時間撹拌を続ける。ピリジンの塩酸塩が析出してくるので反応終了後、室温で冷却しガラスフィルターによりろ過、分離する。一方、ろ液を水中に投入し撹拌しながらポリマーを析出させる。得られたポリマーは塩素イオンが検出されなくなるまで水洗を行い、減圧下で乾燥させ、白色の数平均分子量≒３５，０００の新規二重結合含有含フッ素共重合体６２．１ｇを得た。図２に赤外線吸収スペクトル（ＩＲ）チャートを示す。１６４０ｃｍ−１付近に二重結合の吸収ピーク（図中矢印で示す）が確認され、水酸基含有含フッ素共重合体の水酸基と不飽和酸クロライドとの脱塩酸反応により本発明の二重結合含有含フッ素共重合体が生成したことがわかる。
【００３６】
このポリマーを酢酸エチルに溶解させ３０％の酢酸エチル溶液を調製した。
【００３７】
この酢酸エチル溶液を黒色ガラス瓶に入れ密栓した後、暗所で５０℃に保ち溶液の粘度変化を経時に調べたところ、１か月後も粘度の増加は見られず、初期粘度のままであった。
【００３８】
次に上記３０％溶液を１０％に希釈した溶液１００ｇに１−ヒドロキシ−シクロヘキシルフェニルケト（日本チバガイギー（株）製）０．３ｇを加え、ＪＩＳＲ３２０２ガラス板上にアプリケータにより塗布し、出力４００Ｗ高圧水銀ランプ下１０ｃｍで５分間硬化し、厚さ５μｍの硬化塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００３９】
（実施例２）
実施例１で用いた丸底三つ口フラスコに実施例１の［共重合体Ａ］２００ｇおよびピリジン３．５ｇを仕込んだ。一方滴下漏斗にメタクリル酸クロライド５．２６ｇ、酢酸エチル１２ｇを仕込んだ。次いで実施例１と同様な操作を行うと、数平均分子量≒３５，０００の新規二重結合含有含フッ素共重合体５６．７ｇを得られた。
【００４０】
このポリマーを酢酸エチルに溶解させ３０％の酢酸エチル溶液を調製した。
【００４１】
この酢酸エチル溶液を黒色ガラス瓶に入れ密栓した後、暗所で５０℃に保ち溶液の粘度変化を経時に調べたところ、１か月後も粘度の増加は見られず、初期粘度のままであった。
【００４２】
上記３０％溶液を１０％に希釈し、実施例１と同様にして塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００４３】
（実施例３）
実施例１で用いた丸底三つ口フラスコに実施例１の［共重合体Ａ］２００ｇおよびピリジン３．５ｇを仕込んだ。一方滴下漏斗にアクリル酸クロライド４．５６ｇ、酢酸エチル１１ｇを仕込んだ。次いで実施例１と同様な操作を行うと、数平均分子量≒３５，０００の新規二重結合含有含フッ素共重合体５５．３ｇを得られた。
【００４４】
このポリマーを酢酸エチルに溶解させ３０％の酢酸エチル溶液を調製した。
【００４５】
この酢酸エチル溶液を黒色ガラス瓶に入れ密栓した後、暗所で５０℃に保ち溶液の粘度変化を経時に調べたところ、１か月後も粘度の増加は見られず、初期粘度のままであった。
【００４６】
上記３０％溶液を１０％に希釈し、実施例１と同様にして塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００４７】
（実施例４）
実施例１で得た新規二重結合含有含フッ素共重合体３０％溶液を１０％に希釈した溶液１００ｇにアゾビスイソブチロニトリル０．３ｇを加え、ＪＩＳＲ３２０２ガラス板上にアプリケータにより塗布し、１４０℃で５分間熱硬化し、厚さ５μｍの硬化塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００４８】
（比較例１）
内容積１Ｌのステンレス製撹拌機付きオートクレーブに、脱気したのち、ＶＤＦ１０８．２ｇ、ＴＦＥ８６．１ｇ、ＢＶＥ３０．７ｇ、ＨＢＶＥ２５．０ｇ、酢酸エチル４００ｍｌ、およびｔ−ブチルパーオキシピバレート（日本油脂（株）製品「パーブチルＰＶ」）１．２５ｇを入れ、撹拌しながら内温を６０℃に昇温した。１５時間後に撹拌を停止し、未反応モノマーを放気して反応を停止させた。オートクレーブを開放して反応液を取り出した。得られたポリマーを減圧乾燥により単離し、樹脂分水酸基価＝５１、数平均分子量≒３０，０００の水酸基含有含フッ素共重合体２３０ｇを得た。
【００４９】
このポリマーを酢酸エチルに溶解させ３０％の酢酸エチル溶液を調製した。
【００５０】
この酢酸エチル溶液を黒色ガラス瓶に入れ密栓した後、暗所で５０℃に保ち溶液の粘度変化を経時に調べたところ、２日後にゲル化した。
【００５１】
上記３０％溶液を１０％に希釈し、実施例１と同様にして塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００５２】
（比較例２）
内容積１Ｌのステンレス製撹拌機付きオートクレーブに、脱気したのち、ＶＤＦ３１．４ｇ、ＴＦＥ１９．６ｇ、ＣＨＭＡ１６４．８ｇ、ＨＢＶＥ２４．５ｇ、酢酸エチル４００ｍｌ、およびｔ−ブチルパーオキシピバレート（日本油脂（株）製品「パーブチルＰＶ」）１．２５ｇを入れ、撹拌しながら内温を６０℃に昇温した。２０時間後に撹拌を停止し、未反応モノマーを放気して反応を停止させた。オートクレーブを開放して反応液を取り出した。得られたポリマーを減圧乾燥により単離し、樹脂分水酸基価＝９０、数平均分子量≒３５，０００の水酸基含有含フッ素共重合体１８３ｇを得た。
【００５３】
このポリマーを酢酸エチルに溶解させ３０％の酢酸エチル溶液を調製した。
【００５４】
この酢酸エチル溶液を黒色ガラス瓶に入れ密栓した後、暗所で５０℃に保ち溶液の粘度変化を経時に調べたところ、３０日後も粘度の増加は見られず、初期粘度のままであった。
【００５５】
上記３０％溶液を１０％に希釈し、実施例１と同様にして塗膜を得た。得られた硬化塗膜の透明性、鉛筆硬度とゴバン目（セロテープ）試験の結果を表１に示す。
【００５６】
［表１］硬化塗膜の物性
【表１】

＊１鉛筆硬度：ＪＩＳＫ５４００６．１４（鉛筆引っかき試験）による。
＊２ゴバン目（セロテープ）試験：ＪＩＳＫ５４００８．５．２によって１００のゴバン目をつくり、このゴバン目にセロファン粘着テープを圧着し、その後セロファン粘着テープを剥離した際のマス目を数え、密着性を確認する。
＊３耐マジック汚染性：拭き取り溶剤としてエタノールを用い、汚染２４ｈｒ後に拭き取り塗膜状態を観察。
◎：全く跡がつかない
○：ごくわずか跡がつく
△：かなり跡がつく
×：完全に跡が残る
＊４耐酸性：５％ＨＣｌ水溶液による２４ｈｒスポットテスト後の塗膜外観を目視観察。
◎：変化無し
○：ほとんど変化無し
△：やや侵される
×：侵される
＊５耐アルカリ性：５％ＮａＯＨ水溶液による２４ｈｒスポットテスト後の塗膜外観を目視観察。
◎：変化無し
○：ほとんど変化無し
△：やや侵される
×：侵される
【図面の簡単な説明】
【図１】［共重合体Ａ］（実施例１中間体）の赤外線吸収スペクトル（ＩＲ）チャート
【図２】新規二重結合含有含フッ素共重合体（実施例１）の赤外線吸収スペクトル（ＩＲ）チャート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel fluorine-containing copolymer, and more specifically, a part of hydroxyl groups of a hydroxyl group-containing fluorine-containing copolymer having a fluoroolefin, a cyclohexyl group-containing acrylic acid ester, and a hydroxyl group-containing vinyl ether as essential components. The present invention relates to a novel double bond-containing fluorine-containing copolymer that is hard and excellent in adhesiveness, stain resistance, chemical resistance, and weather resistance, characterized in that it is reacted with unsaturated acid chloride.
[0002]
[Prior art]
A fluoroolefin copolymer containing a hydroxyalkyl group is obtained, for example, by copolymerizing a hydroxyalkyl vinyl ether and a fluoroolefin with an alkyl vinyl ether, an alkyl vinyl ester, or the like, if necessary, and used as a base for a room temperature curable coating.
[0003]
A room temperature curable coating based on such a fluoroolefin copolymer is excellent in chemical resistance, weather resistance, stain resistance, heat resistance and the like, but it is necessary to mix a curing agent immediately before application. This is not convenient for work, and attention must be paid to the pot life.
[0004]
[Problems to be solved by the invention]
That is, the object of the present invention is a novel fluorine-containing fluorine-containing fluorine that is hard and can be cured in a short time with light or heat without using a curing agent, and has excellent adhesion, stain resistance, chemical resistance, and weather resistance. It is in providing a copolymer and its manufacturing method.
[0005]
[Means for Solving the Invention]
As a result of intensive studies to develop a fluorine-containing copolymer having the above-mentioned preferable properties, the present inventors have conducted a dehydrochlorination reaction between a portion of the hydroxyl group of the hydroxyl-containing fluorine-containing copolymer and an unsaturated acid chloride. The inventors have found that the above problem can be solved by introducing a double bond into the fluorine-containing copolymer, and have completed the present invention.
[0006]
That is, the present invention is characterized in that a part of a hydroxyl group-containing fluorine-containing copolymer having a fluoroolefin, a cyclohexyl group-containing acrylic acid ester, and a hydroxyl group-containing vinyl ether as essential constituents is reacted with an unsaturated acid chloride. The present invention relates to a novel double bond-containing fluorine-containing copolymer which is hard and excellent in adhesion, stain resistance, chemical resistance and weather resistance.
[0007]
That is, the present invention
(A) 40 to 90 mol% of a fluoroolefin that is vinylidene fluoride, tetrafluoroethylene, or a combination thereof
(B) General formula

(Wherein R ¹ is hydrogen or a methyl group)
(Meth) acrylic acid cyclohexyl ester represented by the formula 1-30 mol%, and (C) the general formula

(Wherein R ² represents an alkylene group having 2 to 5 carbon atoms or a cyclohexyl group)
It is produced by reacting a part of hydroxyl groups of a hydroxyl group-containing fluorine-containing copolymer having 1 to 30 mol% of a hydroxyl group-containing vinyl ether represented by the formula with an unsaturated acid chloride , is hard, adhesive, The present invention provides a novel double bond-containing fluorine-containing copolymer having a number average molecular weight of 1,000 to 50,000, which gives a paint film excellent in stain resistance, chemical resistance, weather resistance, heat resistance and the like. .
[0008]
In the copolymer of the present invention, the fluoroolefin forming the unit (A) is an olefin having at least two fluorine atoms in the molecule, and vinylidene fluoride, tetrafluoroethylene and the like are preferable. These fluoroolefins may be used alone or in combination of two or more.
[0009]
In the copolymer of the present invention, the monomer that forms the unit (B) is represented by the above general formula. Preferable specific examples of such a monomer include cyclohexyl acrylate, cyclohexyl methacrylate and the like, and cyclohexyl methacrylate is particularly preferable.
[0010]
Specific examples of the hydroxyl group-containing vinyl ether forming the unit (C) in the copolymer of the present invention include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, ethylene glycol monoallyl ether, cyclohexyl vinyl ether and the like. Among them, hydroxybutyl vinyl ether, hydroxyethyl vinyl ether, and cyclohexyl vinyl ether are particularly preferable. These hydroxyl group-containing vinyl ethers may be used alone or in combination of two or more.
[0011]
In the copolymer of the present invention, specific examples of the unsaturated acid chloride include acrylic acid chloride, methacrylic acid chloride, cinnamic acid chloride, crotonic acid chloride, oleic acid chloride, tiglic acid chloride and the like.
[0012]
The copolymer of the present invention is hard and can form a coating film that is excellent in adhesion, stain resistance, chemical resistance, weather resistance, heat resistance, etc. Other copolymerizable monomer units may be included within the range not exceeding. Examples of the copolymerizable monomer include alkyl vinyl ethers such as ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether, olefins such as ethylene and propylene, haloolefins such as vinyl chloride and vinylidene chloride, vinyl acetate, n- Examples thereof include vinyl carboxylic acid esters such as vinyl butyrate and vinyl versatate.
[0013]
The copolymer of the present invention comprises 40 to 90 mol% of a polymer unit (A) based on a fluoroolefin, 1 to 30 mol% of a polymer unit (B) based on a cyclohexyl ester of acrylic acid or a cyclohexyl ester of methacrylic acid, and a hydroxyl group. It can be obtained by reacting 1 to 30 mol% of an unsaturated acid chloride with a hydroxyl group-containing fluorine-containing copolymer containing 1 to 30 mol% of the polymer unit (C).
[0014]
When the proportion of the polymerized units (A) is less than 40 mol%, it is not preferable because sufficient stain resistance, chemical resistance and weather resistance cannot be obtained when used as a paint base. On the other hand, when the amount is more than 90 mol%, the solubility in various solvents is lowered, making it difficult to use as a paint base.
[0015]
When the proportion of the polymerized unit (B) is less than the above, the storage stability of the resin solution is lowered, and the solvent resistance and chemical resistance of the cured coating film are undesirably lowered. The polymerization rate is undesirably lowered.
[0016]
When the proportion of the polymerized units (C) is less than the above, the curing reaction is difficult to occur, and the solvent resistance and chemical resistance of the cured coating film are undesirably lowered. Absent.
[0017]
The copolymer of the present invention can be produced by copolymerizing a predetermined proportion of a monomer mixture using a polymerization initiator in the presence or absence of a solvent.
[0018]
As the polymerization initiator, a water-soluble or oil-soluble one is appropriately used depending on the polymerization type and the type of solvent used as desired.
[0019]
Examples of the water-soluble polymerization initiator include a persulfate such as potassium persulfate, hydrogen peroxide, or a redox reducing agent comprising a combination of these with a reducing agent such as sodium bisulfite and sodium thiosulfate, and further to these. An organic initiator such as an inorganic initiator coexisting with a small amount of iron, ferrous salt, silver nitrate or the like, or a dibasic acid salt such as succinic acid peroxide, diglutaric acid peroxide, or monosuccinic acid peroxide is used.
[0020]
Examples of the oil-soluble initiator include peroxyester type peroxides such as t-butyl peroxyisobutyrate and t-butyl peroxyacetate, and dialkyls such as diisopropyl peroxydicarbonate and dinormalpropyl peroxydicarbonate. Peroxydicarbonate, benzoyl peroxide, azobisisobutyronitrile and the like are used.
[0021]
The amount of these polymerization initiators to be used is appropriately selected according to the type, copolymerization reaction conditions, etc., but is 0.005 to 5% by weight, preferably 0.1 to 1%, based on the total amount of monomers. Is selected within the range.
[0022]
The polymerization method is not particularly limited, and for example, bulk polymerization method, suspension polymerization method, emulsion polymerization method, solution polymerization method and the like can be used. Ketones such as methyl ethyl ketone, esters such as ethyl acetate, fluorine A solution polymerization method using a saturated halogenated hydrocarbon having one or more atoms as a solvent, an emulsion polymerization method in an aqueous medium, or the like is preferably used.
[0023]
When copolymerizing in an aqueous medium, a suspension or emulsifier is usually used as a dispersion stabilizer, and a basic buffer is added, and the pH value of the reaction solution during polymerization is 4 or more, preferably 6 or more. It is desirable to make it.
[0024]
The reaction temperature in the copolymerization reaction is appropriately selected according to the kind of the polymerization initiator and the polymerization medium, usually within a range of −30 ° C. to 150 ° C. For example, when copolymerization is performed in an aqueous medium, It is selected in the range of 0 to 100 ° C, preferably 10 to 90 ° C. The reaction pressure is not particularly limited, but is usually selected in the range of 1 to 100 kg / cm ² , preferably 1 to 60 kg / cm ² . Further, the copolymerization reaction can be performed by adding an appropriate chain transfer agent.
[0025]
In the reaction between the copolymer thus obtained and acid chloride, it is effective to add a tertiary amine such as pyridine or triethylamine to the reaction system as a fixing agent for hydrochloric acid by-produced by the reaction. .
[0026]
The temperature in the reaction between the copolymer and the acid chloride is usually 10 ° C to 130 ° C, preferably 25 ° C to 85 ° C.
[0027]
The double bond-containing fluorine-containing copolymer obtained by such a method can be cured by light or heat.
[0028]
Examples of the photocuring initiator include benzoin ether, benzophenone, 1-hydroxy-cyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-monfolinopropane-1, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,2-dimethoxy-1,2-diphenylethane-1-one and the like are used.
[0029]
As the thermosetting initiator, benzoyl peroxide, azobisisobutyronitrile, t-butylperoxy-2-ethylhexanate, t-butylperoxyisopropyl monocarbonate, or the like is used.
[0030]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
[0031]
The molecular weight of the copolymer of the present invention was measured by gel permeation chromatography (GPC) using ethyl acetate as a solvent and polystyrene as a standard substance.
[0032]
The identification of the hydroxyl group-containing fluorine-containing copolymer, which is the intermediate copolymer of the present invention, and the double bond-containing fluorine-containing copolymer, which is the final copolymer, was performed using an infrared absorption spectrum (IR).
[0033]
The hydroxyl value of the fluorinated copolymer was measured according to JIS K0070 .
[0034]
(Example 1)
After degassing into an autoclave (withstand pressure of 100 kg / cm ² ) with a stainless steel stirrer with an internal volume of 1 L, 115.3 g of vinylidene fluoride (hereinafter abbreviated as VDF), 84.4 g of tetrafluoroethylene (hereinafter abbreviated as TFE), 25.3 g of cyclohexyl methacrylate (hereinafter abbreviated as CHMA), 24.5 g of 4-hydroxybutyl vinyl ether (hereinafter abbreviated as HBVE), 400 ml of ethyl acetate, and t-butyl peroxypivalate (Nippon Yushi Co., Ltd. product “Perbutyl PV”) ) 1.25 g was added, and the internal temperature was raised to 60 ° C. while stirring. After 20 hours, stirring was stopped and the reaction was stopped by releasing unreacted monomers. The autoclave was opened and the reaction solution was taken out to obtain a hydroxyl group-containing fluorine-containing copolymer solution having a solid content concentration of 30%, a resin hydroxyl group value = 50 mg-KOH / g (hereinafter the same unit), and a number average molecular weight≈35,000. It was. This is referred to as [Copolymer A]. FIG. 1 shows an infrared absorption spectrum (IR) chart of the dried coating film of [Copolymer A]. A hydroxyl absorption peak (indicated by an arrow in the figure) is observed in the vicinity of 3200 cm-1.
[0035]
In a dark place, 200 g of [Copolymer A] and 3.5 g of pyridine were charged in a 500 cc round bottom three-necked flask equipped with a stirrer, reflux condenser, dropping funnel and calcium chloride tower. Meanwhile, 7.4 g of cinnamic acid chloride and 17.2 g of ethyl acetate are charged into the dropping funnel. While maintaining the temperature at 50 ° C., an ethyl acetate solution of cinnamic acid chloride is added dropwise little by little while stirring. After completion of the dropwise addition, stirring is continued for 5 hours. Since pyridine hydrochloride precipitates, after the reaction is completed, cool at room temperature and filter and separate with a glass filter. On the other hand, the filtrate is put into water and the polymer is precipitated while stirring. The obtained polymer was washed with water until chlorine ions were no longer detected and dried under reduced pressure to obtain 62.1 g of a new double bond-containing fluorine-containing copolymer having a white number average molecular weight ≈35,000. FIG. 2 shows an infrared absorption spectrum (IR) chart. A double bond absorption peak (indicated by an arrow in the figure) was confirmed in the vicinity of 1640 cm-1, and the double bond-containing content of the present invention was determined by dehydrochlorination reaction of the hydroxyl group and unsaturated acid chloride of the hydroxyl group-containing fluorine-containing copolymer. It can be seen that a fluorine copolymer was formed.
[0036]
This polymer was dissolved in ethyl acetate to prepare a 30% ethyl acetate solution.
[0037]
After this ethyl acetate solution was put in a black glass bottle and sealed, the temperature was kept at 50 ° C. in the dark and the change in viscosity of the solution was examined over time. It was.
[0038]
Next, 0.3 g of 1-hydroxy-cyclohexylphenylketo (manufactured by Nippon Ciba-Geigy Co., Ltd.) is added to 100 g of a solution obtained by diluting the above 30% solution to 10%, and the mixture is applied onto a JIS R 3202 glass plate with an output Curing was performed at 10 cm under a 400 W high pressure mercury lamp for 5 minutes to obtain a cured coating film having a thickness of 5 μm. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0039]
(Example 2)
The round bottom three-necked flask used in Example 1 was charged with 200 g of [Copolymer A] of Example 1 and 3.5 g of pyridine. Meanwhile, 5.26 g of methacrylic acid chloride and 12 g of ethyl acetate were charged into the dropping funnel. Subsequently, when the same operation as in Example 1 was performed, 56.7 g of a novel double bond-containing fluorine-containing copolymer having a number average molecular weight ≈ 35,000 was obtained.
[0040]
This polymer was dissolved in ethyl acetate to prepare a 30% ethyl acetate solution.
[0041]
After this ethyl acetate solution was put in a black glass bottle and sealed, the temperature was kept at 50 ° C. in the dark and the change in viscosity of the solution was examined over time. It was.
[0042]
The 30% solution was diluted to 10%, and a coating film was obtained in the same manner as in Example 1. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0043]
(Example 3)
The round bottom three-necked flask used in Example 1 was charged with 200 g of [Copolymer A] of Example 1 and 3.5 g of pyridine. On the other hand, 4.56 g of acrylic acid chloride and 11 g of ethyl acetate were charged into the dropping funnel. Subsequently, when the same operation as in Example 1 was performed, 55.3 g of a novel double bond-containing fluorine-containing copolymer having a number average molecular weight ≈ 35,000 was obtained.
[0044]
This polymer was dissolved in ethyl acetate to prepare a 30% ethyl acetate solution.
[0045]
After this ethyl acetate solution was put in a black glass bottle and sealed, the temperature was kept at 50 ° C. in the dark and the change in viscosity of the solution was examined over time. It was.
[0046]
The 30% solution was diluted to 10%, and a coating film was obtained in the same manner as in Example 1. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0047]
(Example 4)
0.3 g of azobisisobutyronitrile was added to 100 g of a solution obtained by diluting the 30% solution of the novel double bond-containing fluorine-containing copolymer obtained in Example 1 to 10%, and an applicator was applied on the JIS R 3202 glass plate. It was applied and thermally cured at 140 ° C. for 5 minutes to obtain a cured coating film having a thickness of 5 μm. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0048]
(Comparative Example 1)
After degassing into a 1 L stainless steel autoclave with a stirrer, VDF 108.2 g, TFE 86.1 g, BVE 30.7 g, HBVE 25.0 g, ethyl acetate 400 ml, and t-butyl peroxypivalate (Nippon Yushi Co., Ltd.) ) Product “Perbutyl PV”) 1.25 g was added, and the internal temperature was raised to 60 ° C. while stirring. Stirring was stopped after 15 hours, and the reaction was stopped by releasing unreacted monomers. The autoclave was opened and the reaction solution was taken out. The obtained polymer was isolated by drying under reduced pressure to obtain 230 g of a hydroxyl group-containing fluorine-containing copolymer having a resin hydroxyl value of 51 and a number average molecular weight of about 30,000.
[0049]
This polymer was dissolved in ethyl acetate to prepare a 30% ethyl acetate solution.
[0050]
This ethyl acetate solution was put in a black glass bottle and sealed, and then kept at 50 ° C. in the dark, and the change in viscosity of the solution was examined over time. After 2 days, gelation occurred.
[0051]
The 30% solution was diluted to 10%, and a coating film was obtained in the same manner as in Example 1. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0052]
(Comparative Example 2)
After degassing into a 1 L stainless steel autoclave with a stirrer, 31.4 g of VDF, 19.6 g of TFE, 164.8 g of CHMA, 24.5 g of HBVE, 400 ml of ethyl acetate, and t-butyl peroxypivalate (Nippon Yushi Co., Ltd.) ) Product “Perbutyl PV”) 1.25 g was added, and the internal temperature was raised to 60 ° C. while stirring. Stirring was stopped after 20 hours, and the reaction was stopped by releasing unreacted monomers. The autoclave was opened and the reaction solution was taken out. The obtained polymer was isolated by drying under reduced pressure to obtain 183 g of a hydroxyl group-containing fluorine-containing copolymer having a resin hydroxyl value of 90 and a number average molecular weight of approximately 35,000.
[0053]
This polymer was dissolved in ethyl acetate to prepare a 30% ethyl acetate solution.
[0054]
After this ethyl acetate solution was put in a black glass bottle and sealed, it was kept at 50 ° C. in the dark and the change in viscosity of the solution was examined over time. As a result, no increase in viscosity was observed even after 30 days, and the initial viscosity remained unchanged.
[0055]
The 30% solution was diluted to 10%, and a coating film was obtained in the same manner as in Example 1. Table 1 shows the results of the transparency, pencil hardness, and gobang (cello tape) test of the obtained cured coating film.
[0056]
[Table 1] Physical properties of cured coatings [Table 1]

* 1 Pencil hardness: According to JIS K5400 6.14 (pencil scratch test).
* 2 Gobang (cellophane tape) test: Create 100 gobang according to JIS K 5400 8.5.2 , press the cellophane adhesive tape on this gobang, then count the squares when the cellophane adhesive tape is peeled off, Check adhesion.
* 3 Anti-magic stain resistance: Ethanol was used as a wiping solvent, and the state of the wiping film was observed after 24 hours of contamination.
◎: No trace is left. ○: Very trace is left. △: Very trace is left. ×: Trace remains completely. * 4 Acid resistance: Visual observation of the coating film appearance after 24 hr spot test with 5% HCl aqueous solution.
◎: No change ○: Almost no change △: Slightly attacked X: Slightly affected * 5 Alkali resistance: Visual observation of the coating film appearance after 24 hr spot test with 5% NaOH aqueous solution.
◎: No change ○: Almost no change △: Slightly invaded ×: Invaded [Brief description of drawings]
FIG. 1 is an infrared absorption spectrum (IR) chart of [Copolymer A] (Example 1 intermediate). FIG. 2 is an infrared absorption spectrum (IR) of a novel double bond-containing fluorine-containing copolymer (Example 1). )chart

Claims

(A) 40 to 90 mol% of a fluoroolefin that is vinylidene fluoride, tetrafluoroethylene, or a combination thereof
(B) General formula

(Wherein R ¹ is hydrogen or a methyl group)
(Meth) acrylic acid cyclohexyl ester represented by 1 to 30 mol%, and (C) the general formula

(Wherein R ² represents an alkylene group having 2 to 5 carbon atoms or a cyclohexyl group)
Hydroxyl group-containing part of the hydroxyl groups of the fluorine-containing copolymer is prepared by reacting an unsaturated acid chloride, a number average molecular weight 1 to 1 to 30 mole% hydroxyl-containing vinyl ether represented in the essential components, A fluorine-containing copolymer containing 000 to 50,000 double bonds .

A cured coating film obtained by applying and curing the fluorine-containing copolymer according to claim 1.

(Wherein R ¹¹ Is hydrogen or a methyl group)
1 to 30 mol% of (meth) acrylic acid cyclohexyl ester represented by:
(C) General formula

(Wherein R ²² Represents an alkylene group having 2 to 5 carbon atoms or a cyclohexyl group)
Including a step of reacting a portion of the hydroxyl group of the hydroxyl group-containing fluorocopolymer having 1 to 30 mol% of the hydroxyl group-containing vinyl ether represented by the formula in an unsaturated acid chloride and ethyl acetate. A method for producing a fluorine-containing copolymer.

A method for producing a cured coating film, comprising a step of curing the double bond-containing fluorine-containing copolymer according to claim 1 with light or heat in the absence of a curing agent.