JP3882872B2 - Process for producing alkenylphenol polymer - Google Patents

Description

（式中Ｒ¹は、水素原子又はメチル基を表し、Ｒ²は、炭素数が１〜６のアルキル基を表す）で表されるフェノール残基の水酸基が飽和脂肪族系保護基により保護された化合物を単独重合、あるいはこれとビニル芳香族化合物とを共重合した後、飽和脂肪族系保護基を脱離させて、単独重合体又は共重合体からなるアルケニルフェノール系重合体を得る方法において、脱離剤として下記一般式（II）
ＸＨＳＯ₄ ……（II）
（式中Ｘは、アルカリ金属を表す）で表される重硫酸塩を用いることを特徴とするアルケニルフェノール系重合体の製造方法に関する。
【０００８】
また本発明は、共重合体がランダム共重合体又はブロック共重合体である上記アルケニルフェノール系重合体の製造方法や、上記一般式（II）ＸＨＳＯ₄ におけるＸがリチウム、カリウム、又はナトリウムである上記アルケニルフェノール系重合体の製造方法や、一般式（II）で表される重硫酸塩の添加量が、重合体１００重量部に対して０．１〜１００重量部である上記のアルケニルフェノール系重合体の製造方法に関する。
【０００９】
【発明の実施の形態】
本発明において用いられる一般式（Ｉ）で表される化合物としては、ｐ−ｎ−ブトキシスチレン、ｐ−ｓｅｃ−ブトキシスチレン、ｐ−ｔｅｒｔ−ブトキシスチレン、ｐ−ｔｅｒｔ−ブトキシ−α−メチルスチレン、ｍ−ｔｅｒｔ−ブトキシスチレン、ｍ−ｔｅｒｔ−ブトキシ−α−メチルスチレン等を具体的に例示することができ、これらは一種単独又は二種以上の混合物として使用することができる。
【００１０】
本発明において用いられるビニル芳香族化合物としては、スチレン、ｏ−メチルスチレン、ｐ−メチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、α−メチルスチレン等を具体的に例示することができ、これらは一種単独又は二種以上の混合物として使用することができる。
【００１１】
本発明においては、上記一般式（Ｉ）で示される、フェノール残基の水酸基が飽和脂肪族系保護基により保護された化合物を単独重合、あるいは該化合物とビニル芳香族化合物とを併用して共重合が行われるが、これらの重合方法としては公知のアニオン重合法又はラジカル重合法を適用することができる。
【００１２】
アニオン重合法は、アルカリ金属又は有機アルカリ金属を重合開始剤として、通常、窒素、アルゴン等の不活性ガス雰囲気下、有機溶媒中において、−１００〜５０℃の温度で行われる。そして、共重合においては、モノマー類を反応系に逐次添加して重合することによりブロック共重合体が、また、前記一般式（Ｉ）で示される化合物とビニル芳香族化合物との混合物を反応系に添加して重合することによりランダム共重合体が得られる。
【００１３】
上記重合開始剤のアルカリ金属としては、リチウム、ナトリウム、カリウム、セシウム等が例示され、有機アルカリ金属としては、上記アルカリ金属のアルキル化物、アリル化物及びアリール化物が使用することができ、具体的には、エチルリチウム、ｎ−ブチルリチウム、ｓｅｃ−ブチルリチウム、ｔｅｒｔ−ブチルリチウム、エチルナトリウム、リチウムビフェニル、リチウムナフタレン、リチウムトリフェニル、ナトリウムナフタレン、α−メチルスチレンナトリウムジアニオン、１，１−ジフェニルヘキシルリチウム、１，１−ジフェニル−３−メチルペンチルリチウム等を例示することができる。
【００１４】
また、有機溶媒としては、ｎ−ヘキサン、ｎ−ヘプタン等の脂肪族炭化水素類、シクロヘキサン、シクロペンタン等の脂環族炭化水素類、ベンゼン、トルエン等の芳香族炭化水素類、ジエチルエーテル、テトラヒドロフラン、ジオキサン等のエーテル類の他、アニソール、ヘキサメチルホスホルアミド等の通常アニオン重合において使用される有機溶媒を挙げることができ、これらは単独溶媒又は二種以上の混合溶媒として使用される。
【００１５】
ラジカル重合法は、アゾビスイソブチロニトリル、アゾビスイソバレロニトリル等のアゾ化合物や、過酸化ベンゾイル、メチルエチルケトンパーオキサイド、クメンハイドロパーオキサイドなどの有機過酸化物のような公知のラジカル重合開始剤を用い、必要に応じて１−ドデカンチオール等の公知の連鎖移動剤を併用して、通常、ベンゼン、トルエンなどの芳香族炭化水素類、エチレングリコールモノブチルエーテル、エチレングリコールモノエチルエーテルアセテート、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテルなどの多価アルコール誘導体類などの有機溶媒中において、窒素、アルゴン等の不活性ガス雰囲気下、５０〜２００℃の温度で行われる。
【００１６】
この方法においては、全モノマーを混合物として反応系に添加することによりランダム共重合体が、いずれかのモノマーの全部又は一部を後から添加することによりテーバブロック共重合体が得られる。また、ＴＥＭＰＯ（２，２，６，６−テトラメチルピペリジン−１−オキシル）を用いたラジカル重合法やＣｕ（Ｉ）／Ｃｕ（II）レドックスプロセスを用いた原子移動ラジカル重合法などのいわゆるリビングラジカル重合法により得られる、前記構成成分からなる重合体も本発明に包含される。
【００１７】
次に、アニオン重合法又はラジカル重合法により得られる重合体から飽和脂肪族系保護基を脱離させ、アルケニルフェノール骨格を生成せしめる反応は、通常、溶媒の存在下、下記一般式（II）
ＸＨＳＯ₄ ……（II）
（式中、Ｘはアルカリ金属を表す）で表される重硫酸塩を加えて、室温〜１５０℃の温度で行われる。溶媒としては、ｎ−ヘキサン、ｎ−ヘプタン等の脂肪族炭化水素類、シクロヘキサン、シクロペンタン等の脂環族炭化水素類、ベンゼン、トルエン等の芳香族炭化水素類、メタノール、エタノール等のアルコール類、メチルエチルケトン等のケトン類、メチルセロソルブ、エチルセロソルブ等の多価アルコール誘導体類、水などを例示することができ、これらは単独溶媒又は二種以上の混合溶媒として用いられる。
【００１８】
上記一般式（II）で表される重硫酸塩としては、硫酸水素リチウム、硫酸水素カリウム、硫酸水素ナトリウムなどのアルカリ金属塩の一種又は二種以上の混合物を使用することができるが、その中でも特にカリウム塩やナトリウム塩が好ましい。また、これらの重硫酸塩は水和物となっていてもよい。重硫酸塩の添加量は、重合体１００重量部に対して重硫酸塩０．１〜１００重量部が好ましく用いられる。
【００１９】
【実施例】
本発明を実施例、および比較例により、更に詳細に説明する。但し、本発明の範囲は、下記実施例により何ら制限を受けるものではない。
実施例１
窒素雰囲気下において、トルエン１４００ｇとテトラヒドロフラン（以下、ＴＨＦと略す）１００ｇとからなる混合溶媒中に、ｎ−ブチルリチウム（以下、ＮＢＬと略す）３０ミリモルを加え、撹拌下、−４０℃に保持しながら、ｐ−ｔｅｒｔ−ブトキシスチレン（以下、ＰＴＢＳＴと略す）１．０モルを１時間かけて滴下、さらに反応を１時間継続し、ガスクロマトグラフィー（以下、ＧＣと略す）により反応完結を確認した。ついで、反応系にメタノールを加えて反応を停止させ、反応液を大量のメタノール中に投入してポリマーを析出させ、濾過、洗浄後、６０℃で１５時間減圧乾燥して白色粉体状のポリマーを得た。用いたモノマー総量に対する重合収率は９９．５％であった。このポリマーについて、ゲルパーミィエイションクロマトグラフィー（以下、ＧＰＣと略す）により分析したところ、Ｍｎ＝６５００、Ｍｗ／Ｍｎ＝１．０８の単分散ポリマーであった。
【００２０】
次に、得られたポリマー２０ｇをトルエン／エタノール＝１／４（重量比）の混合溶媒に溶解して２０％溶液とし、硫酸水素ナトリウム２ｇ（１６．６６ミリモル）を加えて６５℃で反応を行った。反応経過は赤外線吸収スペクトル（以下、ＩＲと略す）で追跡し、ｔ−ブトキシ基由来の８９０ｃｍ^-1の吸収が２．５時間後に消失したので終点とした。反応液を濾過して析出している硫酸水素ナトリウムを除去した後、濾液に濾液と同量の酢酸エチル及び２倍量の水を加えて分液を行った。この操作により得られた水層のｐＨは４であり、また、有機層（ポリマー層）中のナトリウム含有量について誘導結合プラズマ質量分析装置（以下、ＩＣＰ−ＭＳと略す）により分析したところ、その測定値から推定される硫酸水素ナトリウムの残留量は約０．１２ミリモルであった。
【００２１】
次いで、前記有機層を濃縮し、エタノールに再溶解した後、大量の水中に投入してポリマーを析出させ、濾過、洗浄後、７０℃で１５時間減圧乾燥を行い、白色粉体状のポリマー１３．６ｇを得た。得られたポリマーについて、¹Ｈ ＮＭＲを測定したところ、１．３ｐｐｍ付近のｔ−ブチル基由来のピークの消失が確認され、また、ＧＰＣを測定したところ、Ｍｎ＝５６００、Ｍｗ／Ｍｎ＝１．０８の単分散ポリマーであった。また、ＩＣＰ−ＭＳによりナトリウム及び鉄の含有量を定量したところ、双方とも１００ｐｐｂ以下であった。このことから、保護基の脱離反応は短時間に完了し、濾過処理、１回の分液処理、粉末化処理により完全に硫酸水素ナトリウムが除去されることが確認された。
また、金属腐食の有無確認のため、前記有機層を鉄製の撹拌羽根を用いて１時間撹拌処理を行ったところ、金属腐食は皆無に近いレベルであることが確認された。
【００２２】
実施例２
窒素雰囲気下において、トルエン１８００ｇとＴＨＦ２００ｇとからなる混合溶媒中に、ＮＢＬ１５ミリモルを加え、撹拌下、−５０℃に保持しながら、ＰＴＢＳＴ１モルとスチレン０．３モルとの混合物を１時間かけて滴下し、更に１時間反応を継続し、ＧＣにより反応完結を確認した。この段階でのＰＴＢＳＴ−スチレンコポリマーは、Ｍｎ＝１１０００、Ｍｗ／Ｍｎ＝１．０５の単分散ポリマーであった。
【００２３】
次に、得られたポリマー２０ｇをプロピレングリコールモノメチルエーテルに溶解して２０％溶液とし、硫酸水素カリウム０．４ｇ（２．９３ミリモル）を加えて９５℃で反応を行った。反応経過は実施例１同様ＩＲで追跡し、３時間で反応を終了した。反応液を濾過して析出している硫酸水素カリウムを除去した後、濾液に濾液と同量の酢酸エチル及び２倍量の水を加えて分液を行った。この操作により得られた水層のｐＨは５であり、また、有機層（ポリマー層）中のカリウム含有量についてＩＣＰ−ＭＳにより分析したところ、その測定値から推定される硫酸水素カリウムの残留量は約０．０１ミリモルであった。
【００２４】
次いで、前記有機層を濃縮し、エタノールに再溶解した後、大量の水中に投入してポリマーを析出させ、濾過、洗浄後、７０℃で１５時間減圧乾燥を行い、白色粉体状のポリマー１３．６ｇを得た。得られたポリマーについて、¹Ｈ ＮＭＲを測定したところ、１．３ｐｐｍ付近のｔ−ブチル基由来のピークの消失が確認され、また、ＧＰＣを測定したところ、Ｍｎ＝８３００、Ｍｗ／Ｍｎ＝１．０５の単分散ポリマーであった。また、ＩＣＰ−ＭＳによりカリウム及び鉄の含有量を定量したところ、それぞれ１００ｐｐｂ以下であった。このことから、保護基の脱離反応は短時間に完了し、また、濾過処理、１回の分液処理、粉末化処理によりほとんどの硫酸水素カリウムが除去されることが確認された。
また、金属腐食の有無確認のため、前記有機層を鉄製の撹拌羽根を用いて１時間撹拌処理を行ったところ、金属腐食は皆無に近いレベルであることが確認された。
【００２５】
実施例３
窒素雰囲気下において、プロピレングリコールモノエチルエーテル２８０ｇ中に、ＰＴＢＳＴ０．７１モル、アゾビスイソブチロニトリル０．０４モル、１−ドデカンチオール０．００７モルを加えて、撹拌下、７０℃で５時間、更に８５℃で５時間反応を行った。次いで、反応液に、反応液と同量のヘキサン、倍量のメタノール及び少量の水を加えて分液精製により未反応のモノマーを除去した後、ポリマー層から溶媒分を減圧溜去して淡褐色粉体状のポリマーを得た。用いたモノマー総量に対する収率は８８．６％であった。このポリマーのＧＰＣ分析を行ったところ、Ｍｎ＝９２００，Ｍｗ／Ｍｎ＝１．４５の低分子量側にショルダーを有するポリマーであった。
【００２６】
次に、得られたポリマー２０ｇをトルエン／エタノール＝１／４の混合溶媒に溶解して２０％溶液とし、硫酸水素ナトリウム水和物６ｇ（４３．４５ミリモル）を加えて５０℃で反応を行った。反応経過は実施例１同様ＩＲで追跡し、３時間で反応を終了した。反応液を濾過して析出している硫酸水素ナトリウムを除去した後、濾液に濾液と同量の酢酸エチル及び２倍量の水を加えて分液を行った。この操作により得られた水層のｐＨは４であり、また、有機層（ポリマー層）中のナトリウム含有量についてＩＣＰ−ＭＳにより分析、その測定値から推定される硫酸水素ナトリウムの残留量は約０．２１ミリモルであった。
【００２７】
次いで、前記有機層を濃縮し、エタノールに再溶解した後、大量の水中に投入してポリマーを析出させ、濾過、洗浄後、７０℃で１５時間減圧乾燥を行い、白色粉体状のポリマー１３．６ｇを得た。得られたポリマーについて、¹Ｈ ＮＭＲを測定したところ、１．３ｐｐｍ付近のｔ−ブチル基由来のピークの消失が確認され、また、ＧＰＣを測定したところ、Ｍｎ＝８３００、Ｍｗ／Ｍｎ＝１．０５の低分子量側にショルダーを有するポリマーであった。また、ＩＣＰ−ＭＳによりナトリウム及び鉄の含有量を定量したところ、両金属とも１００ｐｐｂ以下であった。このことから、保護基の脱離反応は短時間に完了し、濾過処理、１回の分液処理、粉末化処理により完全に硫酸水素カリウムが除去されることが確認された。
また、金属腐食の有無確認のため、前記有機層を鉄製の撹拌羽根を用いて１時間撹拌処理を行ったところ、金属腐食は皆無に近いレベルであることが確認された。
【００２８】
比較例１
実施例１で得られたＰＴＢＳＴポリマー２０ｇをトルエン／エタノール＝１／４（重量比）の混合溶媒に溶解して２０％溶液とし、３５％濃塩酸３．５５ｇを加えて６５℃で反応を行った。反応経過は実施例１同様にＩＲで追跡し、４時間で反応を終了した。反応液に同量の酢酸エチル及び２倍量の水を加えて分液処理を行った。この段階の水層のｐＨは１であった。さらに、有機層に水を加えて分液する水洗処理を５回繰り返し、５回目に得られた水層のｐＨを測定したところ４であった。次いで、この有機層を濃縮し、エタノールに再溶解した後、大量の水中に投入してポリマーを析出させ、濾過、洗浄後、７０℃で１５時間減圧乾燥を行い、白色粉体状のポリマー１３．６ｇを得た。
【００２９】
得られたポリマーの¹Ｈ ＮＭＲ及びＧＰＣの測定結果は実施例１と同様であったが、ＩＣＰ−ＭＳにより鉄の含有量を定量したところ、２５ｐｐｍであった。
以上のことから、保護基の脱離反応は完了しているが、合計６回の水洗処理では塩酸を完全に除去することが出来ないことがわかった。また、金属腐食の有無確認のため、前記有機層を鉄製の撹拌羽根を用いて１時間の撹拌処理を行ったところ、金属が腐食されていることが確認された。
【００３０】
比較例２
比較例１において、トルエン／エタノール混合溶媒に代えてプロピレングリコールモノメチルエーテルを、また、濃塩酸３．５５ｇに代えて硫酸１ｇ、反応温度を９０℃とする以外は比較例１と同様にして白色粉末状のポリマー１３．６ｇを得た。反応所要時間は５時間、水洗５回目のｐＨは５であった。
【００３１】
得られたポリマーの¹Ｈ ＮＭＲ及びＧＰＣの測定結果は実施例１と同様であったが、ＩＣＰ−ＭＳにより鉄の含有量を定量したところ、３ｐｐｍであった。以上のことから、保護基の脱離反応は完了しているが、合計６回の水洗処理では硫酸を完全に除去することができないことがわかった。また、金属腐食の有無確認のため、前記有機層を鉄製の撹拌羽根を用いて１時間の撹拌処理を行ったところ、比較例１と同様に、金属が腐食されていることが確認された。
【００３２】
【発明の効果】
本発明の方法によると、アルケニルフェノールのフェノール残基の水酸基が飽和脂肪族系保護基により保護された化合物を重合させて得られる重合体から相当するアルケニルフェノール系重合体を得るに際し、飽和脂肪族系保護基の脱離剤として、固体で取り扱いやすく、安価であり、且つ反応後の除去が容易な重硫酸塩を用いるため経済性に優れ、かつ、高純度なアルケニルフェノール系重合体を製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an alkenylphenol-based polymer. More specifically, the present invention relates to a homopolymer of a compound in which a hydroxyl group of a phenol residue is protected with a saturated aliphatic protecting group, or a copolymer of this with a vinyl aromatic compound. The present invention relates to a method for producing an alkenylphenol polymer obtained by removing a saturated aliphatic protecting group from a polymer using a specific reagent.
[0002]
[Prior art]
Conventionally, alkenylphenol-based polymers are known as suitable excimer laser resist materials, and are expected to be used in a wide range of fields such as separation membranes, biocompatible materials, and epoxy resin curing agents. In particular, alkenylphenol polymers represented by p-vinylphenol have been known to be useful as curing agents and antioxidants for epoxy resins as well as resist materials.
[0003]
Various methods for producing alkenylphenol-based polymers have been proposed. After a hydroxyl group of a phenol residue is protected by a saturated aliphatic protecting group, the compound is polymerized by radical polymerization or anionic polymerization. A method for removing a saturated aliphatic protecting group by treating with an acidic reagent in an organic solvent is disclosed in JP-B-63-36602, JP-A-4-279608, JP-A-6-298862, and the like. It is disclosed. In these methods, acidic reagents used for elimination of saturated aliphatic protecting groups include hydrochloric acid, sulfuric acid, hydrogen chloride gas, hydrobromic acid, 1,1,1-trifluoroacetic acid, p-toluenesulfonic acid Organic or inorganic acids such as borohydrofluoric acid are generally used.
[0004]
[Problems to be solved by the invention]
Any of the acidic reagents used in the above conventional method for removing a saturated aliphatic protecting group dissolves in the reaction solution after the reaction to form a uniform solution. Therefore, as the removal method, the reaction solution is washed with water. Further, a method of further separating the liquid is generally used. However, it is difficult to completely remove the used acidic reagent even if it is repeatedly washed with water and separated, and the alkenylphenol-based polymer is not very economical, especially when carried out on an industrial scale. As a result of corrosion of peripheral equipment by residual acid during filtration or drying for removing the powder as a powder, alkenylphenol polymer powder may be contaminated by metal ions generated by the corrosion. In addition, the use of contaminated alkenylphenol polymer powder as a resist material for semiconductors has been a practical problem.
[0005]
An object of the present invention is to homopolymerize a compound in which the hydroxyl group of the phenol residue is protected by a saturated aliphatic protecting group, or copolymerize it with a vinyl aromatic compound, and then convert the saturated aliphatic protecting group to a solid It is an object of the present invention to provide a method for producing an alkenylphenol-based polymer that is easy to handle, inexpensive, and desorbed with a specific reagent that can be easily removed after the reaction.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have homopolymerized a compound in which the hydroxyl group of alkenylphenol is protected with a saturated aliphatic protecting group, or after copolymerizing it with a vinyl aromatic compound. In the method for obtaining an alkenylphenol polymer by removing a saturated aliphatic protecting group, an alkali metal salt of bisulfuric acid is used as a leaving agent, which is economical and highly pure. The inventors have found that a coalescence can be produced and have completed the present invention.
[0007]
That is, the present invention provides the following general formula (I)
[Chemical 2]

(Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 6 carbon atoms), the hydroxyl group of the phenol residue represented by is protected by a saturated aliphatic protecting group. In a method for obtaining an alkenylphenol polymer comprising a homopolymer or a copolymer by homopolymerizing the obtained compound or copolymerizing it with a vinyl aromatic compound and then removing the saturated aliphatic protecting group. As a desorbing agent, the following general formula (II)
XHSO ₄ (II)
(Wherein X represents an alkali metal). The present invention relates to a method for producing an alkenylphenol polymer characterized by using a bisulfate represented by the following formula.
[0008]
The present invention also provides a method for producing the alkenylphenol-based polymer, wherein the copolymer is a random copolymer or a block copolymer, or X in the general formula (II) XHSO ₄ is lithium, potassium, or sodium. The production method of the alkenylphenol-based polymer and the alkenylphenol-based, wherein the addition amount of the bisulfate represented by the general formula (II) is 0.1 to 100 parts by weight with respect to 100 parts by weight of the polymer The present invention relates to a method for producing a polymer.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the compound represented by the general formula (I) used in the present invention include pn-butoxystyrene, p-sec-butoxystyrene, p-tert-butoxystyrene, p-tert-butoxy-α-methylstyrene, Specific examples include m-tert-butoxystyrene, m-tert-butoxy-α-methylstyrene, and the like can be used alone or as a mixture of two or more.
[0010]
Specific examples of the vinyl aromatic compound used in the present invention include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, α-methylstyrene, and the like. Or it can be used as a mixture of two or more.
[0011]
In the present invention, a compound represented by the above general formula (I) in which the hydroxyl group of the phenol residue is protected by a saturated aliphatic protecting group is homopolymerized, or the compound and a vinyl aromatic compound are used in combination. Polymerization is carried out, and as these polymerization methods, known anionic polymerization methods or radical polymerization methods can be applied.
[0012]
The anionic polymerization method is usually performed at a temperature of −100 to 50 ° C. in an organic solvent under an inert gas atmosphere such as nitrogen or argon using an alkali metal or an organic alkali metal as a polymerization initiator. In the copolymerization, a block copolymer is obtained by sequentially adding monomers to the reaction system for polymerization, and a mixture of the compound represented by the general formula (I) and the vinyl aromatic compound is reacted in the reaction system. A random copolymer is obtained by adding to the polymer and polymerizing.
[0013]
Examples of the alkali metal of the polymerization initiator include lithium, sodium, potassium, cesium and the like. As the organic alkali metal, alkylated products, allylated products and arylated products of the above alkali metals can be used. Is ethyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, ethyl sodium, lithium biphenyl, lithium naphthalene, lithium triphenyl, sodium naphthalene, α-methylstyrene sodium dianion, 1,1-diphenylhexyl lithium 1,1-diphenyl-3-methylpentyl lithium and the like.
[0014]
Examples of the organic solvent include aliphatic hydrocarbons such as n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane and cyclopentane, aromatic hydrocarbons such as benzene and toluene, diethyl ether, and tetrahydrofuran. In addition to ethers such as dioxane, organic solvents such as anisole and hexamethylphosphoramide, which are usually used in anionic polymerization, can be used, and these are used as a single solvent or a mixed solvent of two or more kinds.
[0015]
Radical polymerization methods are known radical polymerization initiators such as azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide and cumene hydroperoxide. And optionally using a known chain transfer agent such as 1-dodecanethiol, usually aromatic hydrocarbons such as benzene and toluene, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, propylene glycol In an organic solvent such as polyhydric alcohol derivatives such as monomethyl ether and propylene glycol monoethyl ether, the reaction is performed at a temperature of 50 to 200 ° C. under an inert gas atmosphere such as nitrogen and argon.
[0016]
In this method, a random copolymer is obtained by adding all the monomers as a mixture to the reaction system, and a taber block copolymer is obtained by adding all or part of any of the monomers later. In addition, a so-called living such as a radical polymerization method using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and an atom transfer radical polymerization method using a Cu (I) / Cu (II) redox process. Polymers comprising the above-described constituents obtained by radical polymerization are also included in the present invention.
[0017]
Next, the reaction for removing a saturated aliphatic protecting group from a polymer obtained by an anionic polymerization method or a radical polymerization method to form an alkenylphenol skeleton is usually carried out in the presence of a solvent in the following general formula (II).
XHSO ₄ (II)
(Wherein X represents an alkali metal) is added, and the reaction is performed at a temperature of room temperature to 150 ° C. Examples of the solvent include aliphatic hydrocarbons such as n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane and cyclopentane, aromatic hydrocarbons such as benzene and toluene, and alcohols such as methanol and ethanol. And ketones such as methyl ethyl ketone, polyhydric alcohol derivatives such as methyl cellosolve and ethyl cellosolve, water and the like can be exemplified, and these are used as a single solvent or a mixed solvent of two or more kinds.
[0018]
As the bisulfate represented by the general formula (II), one or a mixture of two or more alkali metal salts such as lithium hydrogen sulfate, potassium hydrogen sulfate, and sodium hydrogen sulfate can be used. In particular, potassium salt and sodium salt are preferable. These bisulfates may be hydrates. The amount of bisulfate added is preferably 0.1 to 100 parts by weight of bisulfate with respect to 100 parts by weight of the polymer.
[0019]
【Example】
The present invention will be described in more detail with reference to examples and comparative examples. However, the scope of the present invention is not limited by the following examples.
Example 1
Under a nitrogen atmosphere, 30 mmol of n-butyllithium (hereinafter abbreviated as NBL) was added to a mixed solvent consisting of 1400 g of toluene and 100 g of tetrahydrofuran (hereinafter abbreviated as THF), and the mixture was kept at -40 ° C. with stirring. However, 1.0 mol of p-tert-butoxystyrene (hereinafter abbreviated as PTBST) was added dropwise over 1 hour, and the reaction was continued for 1 hour, and the completion of the reaction was confirmed by gas chromatography (hereinafter abbreviated as GC). . Next, methanol is added to the reaction system to stop the reaction, the reaction solution is poured into a large amount of methanol to precipitate a polymer, filtered, washed, and dried under reduced pressure at 60 ° C. for 15 hours to obtain a white powdery polymer. Got. The polymerization yield based on the total amount of monomers used was 99.5%. When this polymer was analyzed by gel permeation chromatography (hereinafter abbreviated as GPC), it was a monodisperse polymer with Mn = 6500 and Mw / Mn = 1.08.
[0020]
Next, 20 g of the obtained polymer was dissolved in a mixed solvent of toluene / ethanol = 1/4 (weight ratio) to make a 20% solution, 2 g (16.66 mmol) of sodium hydrogen sulfate was added, and the reaction was performed at 65 ° C. went. The course of the reaction was followed by an infrared absorption spectrum (hereinafter abbreviated as IR), and the end point was determined because the absorption at 890 cm ⁻¹ derived from the t-butoxy group disappeared after 2.5 hours. The reaction solution was filtered to remove precipitated sodium hydrogen sulfate, and then the same amount of ethyl acetate and double amount of water as the filtrate were added to the filtrate for liquid separation. The pH of the aqueous layer obtained by this operation was 4, and the sodium content in the organic layer (polymer layer) was analyzed by an inductively coupled plasma mass spectrometer (hereinafter abbreviated as ICP-MS). The residual amount of sodium hydrogen sulfate estimated from the measured value was about 0.12 mmol.
[0021]
Next, the organic layer is concentrated and redissolved in ethanol, and then poured into a large amount of water to precipitate a polymer. After filtration and washing, the polymer is dried under reduced pressure at 70 ° C. for 15 hours to obtain a white powdery polymer 13 0.6 g was obtained. When ¹ H NMR of the obtained polymer was measured, the disappearance of the peak derived from the t-butyl group near 1.3 ppm was confirmed, and when GPC was measured, Mn = 5600, Mw / Mn = 1. It was a monodisperse polymer of 08. Moreover, when content of sodium and iron was quantified by ICP-MS, both were 100 ppb or less. From this, it was confirmed that the elimination reaction of the protecting group was completed in a short time, and sodium hydrogen sulfate was completely removed by filtration, one liquid separation treatment, and powdering treatment.
Moreover, when the said organic layer was stirred for 1 hour using the iron stirring blade in order to confirm the presence or absence of metal corrosion, it was confirmed that there was almost no metal corrosion.
[0022]
Example 2
Under a nitrogen atmosphere, 15 mmol of NBL was added to a mixed solvent consisting of 1800 g of toluene and 200 g of THF, and a mixture of 1 mol of PTBST and 0.3 mol of styrene was added dropwise over 1 hour while maintaining at −50 ° C. with stirring. The reaction was further continued for 1 hour, and the completion of the reaction was confirmed by GC. The PTBST-styrene copolymer at this stage was a monodisperse polymer with Mn = 11000 and Mw / Mn = 1.05.
[0023]
Next, 20 g of the obtained polymer was dissolved in propylene glycol monomethyl ether to form a 20% solution, and 0.4 g (2.93 mmol) of potassium hydrogensulfate was added and reacted at 95 ° C. The reaction progress was followed by IR as in Example 1, and the reaction was completed in 3 hours. The reaction solution was filtered to remove precipitated potassium hydrogen sulfate, and the filtrate was subjected to liquid separation by adding the same amount of ethyl acetate and double amount of water as the filtrate. The pH of the aqueous layer obtained by this operation was 5, and when the potassium content in the organic layer (polymer layer) was analyzed by ICP-MS, the residual amount of potassium hydrogen sulfate estimated from the measured value Was about 0.01 mmol.
[0024]
Next, the organic layer is concentrated and redissolved in ethanol, and then poured into a large amount of water to precipitate a polymer. After filtration and washing, the polymer is dried under reduced pressure at 70 ° C. for 15 hours to obtain a white powdery polymer 13 0.6 g was obtained. When ¹ H NMR of the obtained polymer was measured, the disappearance of the peak derived from the t-butyl group near 1.3 ppm was confirmed, and when GPC was measured, Mn = 8300, Mw / Mn = 1. 05 monodisperse polymer. Moreover, when content of potassium and iron was quantified by ICP-MS, it was 100 ppb or less, respectively. From this, it was confirmed that the elimination reaction of the protecting group was completed in a short time, and most of the potassium hydrogen sulfate was removed by filtration, one liquid separation treatment, and powdering treatment.
Moreover, when the said organic layer was stirred for 1 hour using the iron stirring blade in order to confirm the presence or absence of metal corrosion, it was confirmed that there was almost no metal corrosion.
[0025]
Example 3
Under a nitrogen atmosphere, 0.71 mol of PTBST, 0.04 mol of azobisisobutyronitrile and 0.007 mol of 1-dodecanethiol were added to 280 g of propylene glycol monoethyl ether, and the mixture was stirred at 70 ° C. for 5 hours. The reaction was further carried out at 85 ° C. for 5 hours. Next, after adding the same amount of hexane, double amount of methanol and a small amount of water to the reaction solution and removing the unreacted monomer by liquid separation purification, the solvent component is distilled off under reduced pressure from the polymer layer to obtain a lighter solution. A brown powdery polymer was obtained. The yield based on the total amount of monomers used was 88.6%. When GPC analysis of this polymer was conducted, it was a polymer having a shoulder on the low molecular weight side with Mn = 9200 and Mw / Mn = 1.45.
[0026]
Next, 20 g of the obtained polymer was dissolved in a mixed solvent of toluene / ethanol = 1/4 to form a 20% solution, and 6 g (43.45 mmol) of sodium hydrogensulfate hydrate was added and reacted at 50 ° C. It was. The reaction progress was followed by IR as in Example 1, and the reaction was completed in 3 hours. The reaction solution was filtered to remove precipitated sodium hydrogen sulfate, and then the same amount of ethyl acetate and double amount of water as the filtrate were added to the filtrate for liquid separation. The pH of the aqueous layer obtained by this operation was 4, and the sodium content in the organic layer (polymer layer) was analyzed by ICP-MS. The residual amount of sodium hydrogen sulfate estimated from the measured value was about 0.21 mmol.
[0027]
Next, the organic layer is concentrated and redissolved in ethanol, and then poured into a large amount of water to precipitate a polymer. After filtration and washing, the polymer is dried under reduced pressure at 70 ° C. for 15 hours to obtain a white powdery polymer 13 0.6 g was obtained. When ¹ H NMR of the obtained polymer was measured, the disappearance of the peak derived from the t-butyl group near 1.3 ppm was confirmed, and when GPC was measured, Mn = 8300, Mw / Mn = 1. The polymer had a shoulder on the low molecular weight side of 05. Moreover, when content of sodium and iron was quantified by ICP-MS, both metals were 100 ppb or less. From this, it was confirmed that the elimination reaction of the protecting group was completed in a short time, and potassium hydrogen sulfate was completely removed by filtration treatment, one liquid separation treatment, and powdering treatment.
Moreover, when the said organic layer was stirred for 1 hour using the iron stirring blade in order to confirm the presence or absence of metal corrosion, it was confirmed that there was almost no metal corrosion.
[0028]
Comparative Example 1
20 g of the PTBST polymer obtained in Example 1 was dissolved in a mixed solvent of toluene / ethanol = 1/4 (weight ratio) to make a 20% solution, and 3.55 g of 35% concentrated hydrochloric acid was added and reacted at 65 ° C. It was. The reaction progress was followed by IR as in Example 1, and the reaction was completed in 4 hours. A liquid separation treatment was performed by adding the same amount of ethyl acetate and twice the amount of water to the reaction solution. The pH of the aqueous layer at this stage was 1. Furthermore, it was 4 when the water washing process which adds water to an organic layer and liquid-separates was repeated 5 times, and pH of the water layer obtained 5th was measured. Next, the organic layer is concentrated and redissolved in ethanol, and then poured into a large amount of water to precipitate a polymer. After filtration and washing, the polymer is dried under reduced pressure at 70 ° C. for 15 hours to obtain a white powdery polymer 13 0.6 g was obtained.
[0029]
The measurement results of ¹ H NMR and GPC of the obtained polymer were the same as in Example 1, but the iron content was quantified by ICP-MS and found to be 25 ppm.
From the above, it was found that although the elimination reaction of the protecting group was completed, hydrochloric acid could not be completely removed by a total of 6 water washing treatments. Moreover, when the said organic layer was stirred for 1 hour using the iron stirring blade for the presence or absence confirmation of metal corrosion, it was confirmed that the metal is corroded.
[0030]
Comparative Example 2
In Comparative Example 1, white powder was obtained in the same manner as Comparative Example 1 except that propylene glycol monomethyl ether was used instead of the toluene / ethanol mixed solvent, 1 g of sulfuric acid was used instead of 3.55 g of concentrated hydrochloric acid, and the reaction temperature was 90 ° C. 13.6 g of a polymer was obtained. The time required for the reaction was 5 hours, and the pH at the fifth wash was 5.
[0031]
The results of ¹ H NMR and GPC measurement of the obtained polymer were the same as in Example 1, but the iron content quantified by ICP-MS was 3 ppm. From the above, it was found that although the elimination reaction of the protecting group was completed, sulfuric acid could not be completely removed by a total of 6 water washing treatments. Moreover, when the said organic layer was stirred for 1 hour using the iron stirring blade for the presence or absence confirmation of metal corrosion, it was confirmed similarly to the comparative example 1 that the metal is corroded.
[0032]
【The invention's effect】
According to the method of the present invention, when a corresponding alkenylphenol-based polymer is obtained from a polymer obtained by polymerizing a compound in which the hydroxyl group of the phenol residue of alkenylphenol is protected by a saturated aliphatic protecting group, a saturated aliphatic group is obtained. A bisulfate that is solid, easy to handle, inexpensive, and easy to remove after the reaction is used as a deprotecting agent for the protective group of the system, so that it produces an economical and highly pure alkenylphenol polymer. be able to.

Claims (5)

The following general formula (I)

(Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 6 carbon atoms). The hydroxyl group of the phenol residue represented by In a method for obtaining an alkenylphenol polymer comprising a homopolymer or a copolymer by homopolymerizing the obtained compound or copolymerizing it with a vinyl aromatic compound and then removing the saturated aliphatic protecting group. As a releasing agent, the following general formula (II)
XHSO ₄ (II)
(Wherein X represents an alkali metal) a bisulfate represented by the formula (1) is used. The method for producing an alkenylphenol-based polymer according to claim 1, wherein the copolymer is a random copolymer. 2. The method for producing an alkenylphenol polymer according to claim 1, wherein the copolymer is a block copolymer. Formula X is the (II) XHSO _4, lithium, potassium, or method for producing alkenyl phenols polymer according to any one of claims 1 to 3, characterized in that it is sodium. The alkenyl according to any one of claims 1 to 4, wherein the addition amount of the bisulfate represented by the general formula (II) is 0.1 to 100 parts by weight with respect to 100 parts by weight of the polymer. A method for producing a phenolic polymer.