JP4694711B2 - Method for producing porous material - Google Patents

Description

【００９８】
＜重合率測定＞
重合後に得られた多孔質架橋重合体１．０ｇを塩化メチレン２００ｇ中に加え、２時間撹拌し、濾過後、濾液を島津製作所（株）製ＧＣ−１４、キャピラリーカラムLiquid Phase TC-1(GL Science Inc. 30ｍ×0.53ｍｍ×1.5μｍ)を用いてガスクロマトグラフィーで分析し、多孔質架橋重合体の残存モノマー量を求めた。キャリアーとしてヘリウムガスを用い、インジェクション温度＝２１０℃、ディテクター温度＝２２０℃、カラム温度は４０℃で１０分ホールド後、２０℃／ｍｉｎ．で３分間昇温し、５℃／ｍｉｎ．で１４分昇温、その後２０℃／ｍｉｎ．で２００℃まで昇温した。ＨＩＰＥの調整に供給したモノマー量を１００と換算した場合の残存モノマー量の百分率を算出し、下式を用いて重合率を計算した。
【００９９】
【数２】

【０１００】
（製造例１）
２−エチルヘキシルアクリレート５．１質量部（以下、単に「部」と称する）、４２％ジビニルベンゼン（他成分はｐ−エチル−ビニルベンゼン）３．１部、１．６−へキサンジオールジアクリレート１．１部からなる単量体成分、界面活性剤としてのグリセリンモノオレエート０．６部、ジタロウジメチルアンモニウムメチルサルフェート０．１部を加え、均一に溶解して、油相混合物溶液（以下、「油相」と称する）を調製した。一方、塩化カルシウム１８部をイオン交換水４２５部に溶解して、水相水溶液（以下、「水相」と称する）を調製し、９５℃に加温した。油相と水相を上記比で連続的に乳化機である攪拌混合機内に供給し連続的にＨＩＰＥを形成させた。なお、水相と油相の比は４４．３／１であった。該エマルションの粘度安定性評価等についての結果を表１に記載した。なお、表１において、「水相中の残存重合開始剤量(ppm)」とは、エマルションを形成する際のエマルション形成に使用する水相に含まれる残存重合開始剤量の質量ｐｐｍである。
【０１０１】
得られたＨＩＰＥを連続的に攪拌混合機より抜き出し、あらかじめ９５℃に加熱し、周囲に加熱、保温部材を具備したスタティックミキサーに供給した。スタティックミキサーの入り口より別途水溶性重合開始剤としての過硫酸ナトリウム０．５部を６部のイオン交換水に溶解した液を送り、ＨＩＰＥと重合開始剤を連続的に混合した。これにより最終的に水相と油相の比は４５／１になった。
【０１０２】
このＨＩＰＥを、フレキシブルチューブを通して搬送し、９５℃に加熱しかつ水平に設置した速度０．８〜１．５ｍ／分で走行するベルト上に幅約５０ｃｍ、厚み約５ｍｍのシート状に連続的に供給して成形した。続いて重合温度を９５℃に制御した重合ゾーンを１０分間で通過させた。該重合ゾーンを通過後、ただちに脱水圧縮して、多孔質材料（１）と廃水（１）とを得た。
【０１０３】
（製造例２）
２−エチルヘキシルアクリレート５．１質量部（以下、単に「部」と称する）、４２％ジビニルベンゼン（他成分はｐ−エチル−ビニルベンゼン）３．１部、１，６−へキサンジオールジアクリレート１．１部からなる単量体成分、界面活性剤としてのグリセリンモノオレエート０．６部、ジタロウジメチルアンモニウムメチルサルフェート０．１部を加え、均一に溶解して、油相混合物溶液（以下、「油相」と称する）を調製した。一方、塩化カルシウム１８部をイオン交換水４３２部に溶解して、水相を調製し、９５℃に加温した。油相と水相を上記比で連続的に乳化機である攪拌混合機内に供給し連続的にエマルション（ＨＩＰＥ）を形成させた。水相と油相の比は４５／１であった。該エマルションの粘度安定性評価については、乳化直後の粘度は９８７ｍＰａ・ｓｅｃで、５分後の粘度は９９２ｍＰａ・ｓｅｃであった。
【０１０４】
得られたＨＩＰＥを連続的に攪拌混合機より抜き出し、あらかじめ９５℃に加熱し、周囲に加熱、保温部材を具備したスタティックミキサーに供給した。スタティックミキサーの入り口より別途油溶性重合開始剤としてのｔ−ブチルペルオキシ−２−エチルヘキサノエート０．２２部を送り、ＨＩＰＥと重合開始剤を連続的に混合した。これにより最終的に水相と油相の比は４５／１になった。
【０１０５】
このＨＩＰＥを、フレキシブルチューブを通して搬送し、９５℃に加熱しかつ水平に設置した速度０．８〜１．５ｍ／分で走行するベルト上に幅約５０ｃｍ、厚み約５ｍｍのシート状に連続的に供給して成形した。続いて重合温度を９５℃に制御した重合ゾーンを１０分間で通過させた。該重合ゾーンを通過後、ただちに脱水圧縮して、多孔質材料（２）と廃水（２）とを得た。
【０１０６】
（製造例３）
２−エチルヘキシルアクリレート５．１部、４２％ジビニルベンゼン（他成分はｐ−エチル−ビニルベンゼン）３．１部、１，６−へキサンジオールジアクリレート１．１部からなる単量体成分、界面活性剤としてのグリセリンモノオレエート０．６部、ジタロウジメチルアンモニウムメチルサルフェート０．１部を加え、均一に溶解して、油相を調製した。一方、塩化カルシウム１８部をイオン交換水４３２部に溶解して、水相を調製し、９５℃に加温した。
【０１０７】
油相と水相を上記比で連続的に乳化機である攪拌混合機内に供給し連続的にＨＩＰＥを形成させた。水相と油相の比は４５／１であった。該エマルションの粘度安定性評価については、乳化直後の粘度は８８０ｍＰａ・ｓｅｃで、５分後の粘度は８７９ｍＰａ・ｓｅｃであった。
【０１０８】
得られたＨＩＰＥを連続的に攪拌混合機より抜き出し、あらかじめ９５℃に加熱し、周囲に加熱、保温部材を具備したスタティックミキサーに供給した。スタティックミキサーの入口より別途重合開始剤として過硫酸ナトリウム０．５部を６部イオン交換水に溶解した液を送り、ＨＩＰＥと重合開始剤を連続的に混合した。これにより最終的に水相と油相の比は４５／１になった。
【０１０９】
このＨＩＰＥを、フレキシブルチューブを通して搬送し、９５℃に加熱しかつ水平に設置した速度１．６〜３．０ｍ／分で走行するベルト上に幅約５０ｃｍ、厚み約５ｍｍのシート状に連続的に供給して成形した。続いて重合温度を９５℃に制御した重合ゾーンを約５分間で通過させた。該重合ゾーンを通過後、ただちに脱水圧縮して、多孔質材料（２４）と廃水（３）とを得た。
【０１１０】
（実施例１）
製造例１で得た５００部の廃水（１）をセパラブルフラスコに採取し、還流下で１００℃で加熱した。水温が９０℃に達した後、続いて亜硫酸水素ナトリウムを０．２９部を添加して、添加後３０分間加熱し、処理水（１）を得た。処理水（１）に残存重合開始剤量は検出されなかった。
【０１１１】
製造例１と同じ油相を処理水（１）を用いて粘度安定性評価用ＨＩＰＥを形成した。製造例１の油相と水相に処理水（１）４４３部を連続的に攪拌混合機内に供給し連続的にＨＩＰＥを形成させた。水相と油相の比は４４．３／１であった。得られたエマルションを２５０部取り出して、粘度安定性評価を行なった。粘度安定性評価の結果を表１に示す。
【０１１２】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（３）を得た。多孔質材料（３）についての物性を表１に示す。
【０１１３】
（実施例２）
添加後１０分間加熱する以外は実施例１と同じ操作で、処理水（２）を得た。処理水（２）の残存重合開始剤量は検出されなかった。処理水（２）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１１４】
製造例１においてＨＩＰＥ調製用の水相として、処理水（２）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（４）を得た。多孔質材料（４）についての物性を表１に示す。
【０１１５】
（実施例３）
添加後５分間加熱する以外は実施例１と同じ操作で、処理水（３）を得た。処理水（３）の残存重合開始剤量は検出されなかった。処理水（３）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１１６】
製造例１においてＨＩＰＥ調製用の水相として、処理水（３）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（５）を得た。多孔質材料（５）についての物性を表１に示す。
【０１１７】
（実施例４）
亜硫酸水素ナトリウムの添加量を０．３８部添加し、添加後５分間加熱する以外は実施例１と同じ操作で、処理水（４）を得た。処理水（４）の残存重合開始剤量は検出されなかった。処理水（４）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１１８】
製造例１においてＨＩＰＥ調製用の水相として、処理水（４）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（６）を得た。多孔質材料（６）についての物性を表１に示す。
【０１１９】
（実施例５）
亜硫酸水素ナトリウムの添加量を０．１９部添加し、添加後３０分間加熱する以外は、実施例１と同じ操作で処理水（５）を得た。処理水（５）の残存重合開始剤量は８０ｐｐｍであった。処理水（５）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１２０】
製造例１においてＨＩＰＥ調製用の水相として、処理水（５）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（７）を得た。多孔質材料（７）についての物性を表１に示す。
【０１２１】
（実施例６）
製造例１で得た５００ｇの廃水（１）をセパラブルフラスコに採取し、還流下で１００℃で加熱した。水温が９０℃に達した後、続いてＬ−アスコルビン酸０．６４部を添加して、添加後１０分間加熱し、処理水（６）を得た。処理水（６）の残存重合開始剤量は検出されなかった。処理水（６）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１２２】
製造例１においてＨＩＰＥ調製用の水相として、処理水（６）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（８）を得た。多孔質材料（８）についての物性を表１に示す。
【０１２３】
（実施例７）
実施例６においてＬ−アスコルビン酸０．３２部添加する他は同じ操作を行ない、処理水（７）を得た。処理水（７）の残存重合開始剤量は５０ｐｐｍであった。処理水（７）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１２４】
製造例１においてＨＩＰＥ調製用の水相として、処理水（７）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（９）を得た。多孔質材料（９）についての物性を表１に示す。
【０１２５】
（実施例８）
実施例６においてＤ−アスコルビン酸０．３２部添加する他は同じ操作を行ない、処理水（７）を得た。処理水（８）の残存重合開始剤量は６０ｐｐｍであった。処理水（８）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１２６】
製造例１においてＨＩＰＥ調製用の水相として、処理水（８）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１０）を得た。多孔質材料（１０）についての物性を表１に示す。
【０１２７】
（実施例９）
実施例１で得た処理水（１）を水酸化カルシウムを攪拌下でｐＨ７に調整した。その後、沈殿物をろ過することで、処理水（９）を得た。処理水（９）の残存重合開始剤量は検出されなかった。処理水（９）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１２８】
製造例１においてＨＩＰＥ調製用の水相として、処理水（９）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１１）を得た。多孔質材料（１１）についての物性を表１に示す。
【０１２９】
（実施例１０）
処理水（３）を用いた以外は実施例９と同じ操作を行ない、処理水（１０）を得た。処理水（１０）の残存重合開始剤量は検出されなかった。処理水（１０）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１３０】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１０）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１２）を得た。多孔質材料（１２）についての物性を表１に示す。
【０１３１】
（実施例１１）
処理水（４）を用いた他は実施例９と同じ操作を行ない、処理水（１１）を得た。処理水（１１）の残存重合開始剤量は検出されなかった。処理水（１１）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１３２】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１１）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１３）を得た。多孔質材料（１３）についての物性を表１に示す。
【０１３３】
（実施例１２）
処理水（６）を用いた他は実施例９と同じ操作を行ない、処理水（１２）を得た。処理水（１２）の残存重合開始剤量は検出されなかった。処理水（１２）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１３４】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１２）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１４）を得た。多孔質材料（１４）についての物性を表１に示す。
【０１３５】
（実施例１３）
処理水（７）を用いた他は実施例９で同じ操作を行ない、処理水（１３）を得た。処理水（１３）の残存重合開始剤量は４５ｐｐｍであった。処理水（１３）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１３６】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１３）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１５）を得た。多孔質材料（１５）についての物性を表１に示す。
【０１３７】
（実施例１４）
処理水（８）を用いた他は実施例９で同じ操作を行ない、処理水（１４）を得た。処理水（１４）の残存重合開始剤量は５０ｐｐｍであった。処理水（１４）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１３８】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１４）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１６）を得た。多孔質材料（１６）についての物性を表１に示す。
【０１３９】
（実施例１５）
製造例１で得た廃水（１）をオートクレーブ中で加圧下１５０℃で３分間加熱して処理水（１２）を得た。処理水（１５）の残存重合開始剤量は検出され無かった。処理水（１５）を用いたＨＩＰＥの粘度安定性評価結果を表１に示す。
【０１４０】
製造例１においてＨＩＰＥ調製用の水相として、処理水（１５）を用いた以外は、製造例１と同じ操作を行ない多孔質材料（１７）を得た。多孔質材料（１７）についての物性を表１に示す。
【０１４１】
（実施例１６）
製造例１においてＨＩＰＥ調製用の水相として廃水（２）を使用した以外は製造例１と同じ操作を行ない多孔質材料（１８）を得た。多孔質材料（１８）についての物性を表１に示す。
【０１４２】
（実施例１７）
製造例２においてＨＩＰＥ調製用の水相として廃水（２）を使用した以外は製造例２と同じ操作を行ない多孔質材料（１９）を得た。多孔質材料（１９）についての物性を表１に示す。
【０１４３】
（実施例１８）
実施例１で得た処理水（１）４００部に対して１．７部の塩化カルシウムとイオン交換水４１．３部を均一に加えて溶解し処理水（１６）を得た。
【０１４４】
処理水（１６）の残存重合開始剤量は処理水（１）と同じく検出限界以下であった。製造例１と同じ油相を処理水（１６）を用いて、粘度安定性評価用のＨＩＰＥを形成した。製造例１の油相と水相に処理水（１６）４４３部を連続的に撹拌混合機内に供給し、連続的にＨＩＰＥを形成させた。水相と油相の比は４４．３／１であった。得られたエマルションを２５０部取り出して、粘度安定性評価を行った。粘度安定性評価の結果を表１に示す。
【０１４５】
次いで、製造例１においてＨＩＰＥ調整用の水相として処理水（１６）を用いた以外は、製造例１と同じ操作を行い多孔質材料（２０）を得た。多孔質材料（２０）の物性を表１に示す。
【０１４６】
（実施例１９）
実施例９で得た処理水（９）４００部に対して１．７部の塩化カルシウムとイオン交換水４１．３部を均一に加えて溶解し処理水（１７）を得た。処理水（１７）の残存重合開始剤量は処理水（９）と同じく検出限界以下であった。
【０１４７】
製造例１と同じ油相を処理水（１７）を用いて粘度安定性評価用のＨＩＰＥを形成した。製造例1の油相と水相に処理水（１７）４４３部を連続的に撹拌混合機内に供給し、連続的にＨＩＰＥを形成させた。水相と油相の比は４４．３／１であった。得られたエマルションを２５０部取り出して、粘度安定性評価を行った。粘度安定性評価の結果を表１に示す。
【０１４８】
製造例１においてＨＩＰＥ調整用の水相として処理水（１７）を用いた以外は、製造例１と同じ操作を行い、多孔質材料（２１）を得た。多孔質材料（２１）の物性を表１に示す。
【０１４９】
（実施例２０）
廃水（１）を８０℃で３０分加熱して処理水（１８）を得た。処理水（１８）の残存重合開始剤量は６２０ｐｐｍであった。処理水（１８）を用いて実施例１と同じ操作を行い粘度安定性評価を行った。粘度安定性評価結果を表１に示す。実施例１の水相を処理水（１８）に変える以外は実施例１と同じ操作を行い多孔質材料（２２）を得た。多孔質材料（２２）の物性を表１に示す。
【０１５０】
（実施例２１）
製造例３で得た５００部の廃水（３）をセパラブルフラスコに採取し、還流下で１００℃で加熱した。水温が９０℃に達した後、続いて硫酸鉄（II）７水和物を１．２部を添加し混合した。２分後、水酸化カルシウムを添加して０．３部を加えて中和した。中和後、０．２μｍのフィルターでろ過して処理水（１９）を得た。処理水（１９）に残存重合開始剤量は検出されなかった。
【０１５１】
製造例１と同じ油相を処理水（１９）を４４３部連続的に攪拌混合機内に供給し連続的にＨＩＰＥを形成させた。水相と油相の比は４４．３／１であった。得られたエマルションを２５０部取り出して、粘度安定性評価を行なった。粘度安定性評価の結果を表１に示す。製造例１においてＨＩＰＥ調整用の水相として処理水（１９）を用いた以外は製造例１と同じ操作を行ない多孔質材料（２３）を得た。
【０１５２】
（比較例１）
製造例１において使用するＨＩＰＥ調整用の水相として廃水（１）を使用した以外は、製造例１と同じ操作を行ない比較多孔質材料（１）を得た。比較多孔質材料（１）についての物性を表１に示す。
【０１５３】
また、廃水（１）を用いて実施例１と同じ操作を行ない、粘度安定性評価を行なった。粘度安定性評価結果を表１に示す。
【０１５４】
（比較例２）
廃水（１）を６０℃で３０分間加熱して、比較処理水（１）を得た。比較処理水の残存重合開始剤量は８８０ｐｐｍであった。比較処理水（１）を用いて実施例１と同じ操作を行い粘度安定性評価を行った。粘度安定性評価結果を表１に示す。
【０１５５】
実施例１の水相を比較処理水（１）に変える以外は実施例1と同じ操作を行い比較多孔質材料（２）を得た。比較多孔質材料（２）についての物性を表１に示す。
【０１５６】
【表１】

【０１５７】
【発明の効果】
本発明によれば、廃水の有効利用ができる。しかも、ＨＩＰＥを調整する水相として重合開始剤の含有量を低減した後の廃水を用いて、重合開始剤濃度が８００ｐｐｍ以下の水相を使用することでＨＩＰＥを高温でも形成でき、かつ高温で安定に重合させることができる。また、この際のＨＩＰＥの重合温度は、７０℃以上という高温でも安定であるため、これに続く重合時間を短縮することができる。このため、多孔質材料を効率よく製造することができる。しかも、得られた多孔質材料は、圧縮強度にも優れる。
【図面の簡単な説明】
【図１】 図１は、本発明の多孔質材料の製造方法における、好適な連続重合装置の代表的な一実施態様を表す概略側面図である。
【符号の説明】
１０１…ＨＩＰＥ、１０２…多孔質架橋重合体、１０２’…多孔質材料、１１９…ＨＩＰＥ供給部、２０１…エンドレスベルト式のコンベア（駆動搬送装置付き）、２０３，２０５…シート材、２０７，２０８…巻出ローラー、
２０９，２１１…回転ローラー、２１２，２１３…巻取ローラー、
２１５…重合炉、２１７…加熱昇温手段、２１９…加熱昇温手段、
３０１…圧縮ロール、３０２、４０３、４０５…搬送用コンベアロール、
３０３…脱水装置、廃水…３０４、３１０…廃水処理装置、４０１…エンドレスバンドナイフ式スライサー、４０２…バンドナイフ、５０１…油相、５０２…水相、５０３…乳化機。[0001]
BACKGROUND OF THE INVENTION
In the present invention, when producing a porous material by forming a water-in-oil high dispersion phase emulsion (hereinafter referred to as HIPE), when reusing the wastewater used in the aqueous phase forming the HIPE, The present invention relates to a method for producing a porous material in which a polymerization initiator contained is removed and waste water having a polymerization initiator concentration of 800 ppm or less is used.
[0002]
[Prior art]
One method for obtaining a porous material composed of open cells with fine and uniform pore diameter is a method of polymerizing after forming a HIPE composed of a monomer phase and an aqueous phase in the presence of a specific surfactant. In general, HIPE refers to one in which the proportion of the dispersed phase in the total volume of the HIPE exceeds 70% by volume. For example, US Pat. No. 5,334,621 discloses a method for producing a porous material by a HIPE method in which a polymerizable monomer contained in such HIPE is subjected to crosslinking polymerization.
[0003]
In this method, (i) a polymerizable monomer mixture containing an oil-soluble vinyl monomer and a crosslinking monomer having two or more functional groups in the molecule, (ii) 90% by weight of the emulsion, more preferably Prepared HIPE containing 95% by weight, particularly preferably 97% by weight of aqueous phase, (iii) a surfactant such as sorbitan fatty acid ester and glycerol mono fatty acid ester, and (iv) a polymerization initiator, A porous material is produced by heating and polymerizing and crosslinking HIPE. According to this HIPE method, a porous material composed of network-like open cells is formed by reverse phase emulsion polymerization. For this reason, the porous material obtained by the HIPE method has characteristics such as low density and water absorption, retention, heat insulation, and soundproofing.
[0004]
However, the porous material obtained by such a HIPE method has a porous structure formed by the ratio of the water phase which is the inner phase to the oil phase which is the outer phase in the reverse phase emulsion polymerization in the production process, that is, W / O. to be influenced. In order to obtain a porous material having a larger pore volume ratio, the ratio of W / O inevitably increases on the water phase side. Porous material with a large void volume ratio is excellent in heat insulation and soundproofing in addition to absorbability, so it should be used in many fields such as sanitary materials such as disposable diapers and sanitary products, building materials, audio products, and horticulture. Therefore, the demand for such a porous material is great. When the porous material is produced by the HIPE method, generally, W / O is often carried out at 10/1 to 100/1. That is, if an attempt is made to produce a porous material by the HIPE method, a large amount of water is required to form HIPE. This means that when the porous material is produced by the HIPE method, it is necessary to dehydrate and dry the water contained in the porous material after the production of the porous material, and a large amount of waste water is generated. .
[0005]
[Problems to be solved by the invention]
A large amount of waste water obtained in the production process of such a porous material is efficient to reuse in the production process of the porous material because the amount of water used is large. In particular, in the manufacturing process of the porous material, since the most amount of water is used when forming the HIPE, it is preferable to reuse the waste water in the forming process of the HIPE. However, when it is reused without treatment, the formation of HIPE may become difficult or the pH may change due to components or impurities contained in the wastewater. For this reason, wastewater is neutralized and insoluble solids are removed and used by filtration or centrifugation. However, when HIPE is formed, insoluble matters are formed in the HIPE emulsifier and the emulsification operation must be stopped. There are cases where it cannot be obtained.
[0006]
On the other hand, depending on the purpose of use, it is not easy to simply reduce the amount of water used during HIPE formation. This is because the mechanical properties and absorbability of the porous material are governed by the above W / O, so that when the desired porous material is obtained, the weight% of the aqueous phase in HIPE cannot be greatly reduced. . Porous materials are used as sanitary material absorbers, waste oil treatment agents, etc., and are used as heat insulating materials, soundproofing materials, etc., so that they have fine pores in their structures to ensure their sufficient properties Preferably, when the water phase weight% is low as described above, a fine and open-celled porous material cannot be obtained, and the mechanical properties may deteriorate or the water absorption characteristics and the like may deteriorate. In particular, the porous material is a member that is applied in many fields. If the emulsification operation is stopped in the HIPE formation process when continuous production is carried out, the subsequent process must be stopped and the production rate is increased. descend. In particular, the stop in the emulsification process of HIPE tends to occur frequently when the emulsification temperature or polymerization temperature of HIPE is increased to shorten the polymerization time in order to improve the production rate.
[0007]
As described above, a process capable of efficiently obtaining a porous material in a short time and efficiently reusing a large amount of generated wastewater has not been known so far, and development is desired.
[0008]
[Means for Solving the Problems]
The inventors of the present invention have studied a process for producing a porous material by the HIPE method, and when the obtained waste water is subjected to a specific treatment and then used again for the formation of the HIPE, the formation of the HIPE proceeds very smoothly. The inventors have found that the efficiency of the production of porous materials can be improved synergistically because the temperature can be increased, and the present invention has been completed. That is, the present application includes the following (1) to ( 5 ).
[0009]
(1) A step of forming and polymerizing a water-in-oil high-dispersion phase emulsion containing a polymerizable monomer to obtain a porous crosslinked polymer, and a step of dehydrating the porous crosslinked polymer to obtain waste water In the method for producing a porous material, By adding a reducing agent to the wastewater A polymerization initiator contained in the wastewater is reduced, and a water-in-oil type highly dispersed phase emulsion is formed using an aqueous phase containing the wastewater and having a polymerization initiator content of 800 ppm or less, and a temperature of 70 ° C. or higher. A method for producing a porous material, characterized in that polymerization is carried out with
[0012]
( 2 ) The above (1), wherein the water-in-oil highly dispersed phase emulsion is polymerized at a temperature of 70 to 150 ° C ) The manufacturing method as described.
[0013]
( 3 ) A step of forming a water-in-oil highly dispersed phase emulsion, a step of polymerizing a porous crosslinked polymer for polymerizing the emulsion, a step of adjusting wastewater by dehydration of the porous crosslinked polymer, and a polymerization initiator contained in the wastewater. (1), wherein each step is performed continuously. Or (2) The manufacturing method as described in.
[0014]
( 4 ) The above (wherein the production process of the porous crosslinked polymer is performed within 30 minutes) 3 ) Described production method.
[0015]
( 5 ) The above (1) to (1), which have two or more porous material production lines and use the waste water obtained in one production line in another production line. 4 The manufacturing method in any one of).
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The first of the present invention is a step of forming and polymerizing a water-in-oil type highly dispersed phase emulsion containing a polymerizable monomer to obtain a porous crosslinked polymer, and dewatering the porous crosslinked polymer to produce waste water. In a method for producing a porous material including a step of obtaining, a polymerization initiator contained in the wastewater is reduced, and a water-in-oil type high dispersion using an aqueous phase containing the wastewater and having a polymerization initiator content of 800 ppm or less A method for producing a porous material, characterized in that a phase emulsion is formed and further polymerized at a temperature of 70 ° C. or higher.
[0017]
Conventionally, HIPE is generally formed at a temperature of 40 to 65 ° C. Therefore, HIPE is separated in the emulsification step without generating any special treatment on the wastewater, and as a result, a gel is generated. It has not been observed much to form a polymer. However, when the porous material is produced efficiently in a shorter time, it is particularly effective to raise the polymerization temperature and complete the polymerization in a short time. On the other hand, since the increase in the polymerization temperature is more efficiently accelerated by the increase in the emulsification temperature, which is the previous step, the HIPE gel is contained inside the emulsifier by the components contained in the wastewater, particularly the remaining polymerization initiator. A case where a solid product was generated and the emulsifier stopped and continuous operation was not possible was observed. Such an adverse effect occurs particularly when HIPE is adjusted at a high emulsification temperature, and has not been regarded as a significant problem in the past. The present invention reduces the polymerization initiator contained in the wastewater, and efficiently forms HIPE using wastewater having a polymerization initiator concentration of 800 ppm or less, thereby reducing the amount of water phase to be discarded outside the production process. This greatly reduces the production efficiency of the porous material.
[0018]
Here, an example of a mode in which a porous material is continuously produced by polymerizing HIPE will be described with reference to the flow of FIG. As shown in FIG. 1, an oil phase 501 and an aqueous phase 502 are introduced into an emulsifier 503 to form a HIPE 101, and this HIPE 101 is continuously supplied from a HIPE supply unit 119 onto a sheet material 203, and a rotating roller 209 Is formed into a sheet having a predetermined thickness by adjusting the set height. The rotational speed of the unwinding / winding rollers 208 and 212 is controlled so that the sheet material 203 can be synchronized with the conveyor belt 201. The rotation speed of the sheet material 205 is controlled by rotating rollers 209 and 211 and unwinding / winding rollers 207 and 213 while applying tension so that the thickness of the HIPE 101 becomes constant. The HIPE 101 is polymerized in the polymerization furnace 215 by the heating temperature raising means 219 comprising a hot water shower from the lower part of the conveyor belt 201 and the heating temperature raising means 217 comprising a hot air circulating device from above the conveyor belt to thereby form the porous crosslinked polymer 102. obtain. Next, after the upper and lower sheet materials 203 and 205 are peeled off, the porous crosslinked polymer 102 is placed on a belt that is rotated by a conveyor 302 by a rotating roll of a dehydrator 303, and a compression roll provided above and below the belt. The waste water 304 is obtained by dehydrating while rotating the roll sandwiched between 301. The waste water 304 is transferred to the waste water treatment apparatus 310 to remove the polymerization initiator, and this is used as an aqueous phase for forming the HIPE 101. The dehydrated porous material 102 ′ can also be sliced in the thickness direction by a band knife 402 that is transferred to an endless band knife slicer 401 that is continuously provided and rotated. Hereinafter, the present invention will be described in detail.
[0019]
[I] Raw material used for HIPE
The raw material used for HIPE contains (a) a polymerizable monomer (hereinafter also simply referred to as “monomer”), (b) a crosslinkable monomer and (c) a surfactant as essential components constituting the oil phase. And (d) What is necessary is just to contain water as an essential component which comprises a water phase. Further, if necessary, (e) a polymerization initiator, (f) salts, (g) other additives may be contained as optional components constituting the oil phase and / or the aqueous phase.
[0020]
(A) Polymerizable monomer
The polymerizable monomer is not particularly limited as long as it has one polymerizable unsaturated group in the molecule, and can be polymerized in a dispersed or water-in-oil type highly dispersed phase emulsion to form bubbles. It is not limited. Preferably at least a part contains (meth) acrylic acid ester, more preferably contains 20% by mass or more of (meth) acrylic acid ester, and particularly preferably contains 35 mass of (meth) acrylic acid ester. % Or more. By containing (meth) acrylic acid ester as the polymerizable monomer, a porous material rich in flexibility and toughness can be obtained, which is desirable.
[0021]
Specific examples of the polymerizable monomer include arylene monomers such as styrene; monoalkylene arylene monomers such as styrene, ethylstyrene, α-methylstyrene, vinyltoluene, and vinylethylbenzene; (meth) acrylic Methyl methacrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, (meth) (Meth) acrylic esters such as stearyl acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate; chlorine-containing monomers such as vinyl chloride, vinylidene chloride, chloromethylstyrene; acrylonitrile, methacrylonitrile, etc. Acrylonitrile compounds; other, vinyl acetate, propi Nsan vinyl, N- octadecyl acrylamide, ethylene, propylene, butene and the like. These may be used alone or in combination of two or more.
[0022]
The amount of the polymerizable monomer used is preferably in the range of 10 to 99.9% by mass with respect to the mass of the whole monomer component composed of the polymerizable monomer and the following crosslinkable monomer. . This is because a porous material having a fine pore diameter can be obtained within this range. More preferably, it is 30-99 mass%, Most preferably, it is the range of 30-70 mass%. When the amount of the polymerizable monomer used is less than 10% by mass, the resulting porous material may become brittle or the water absorption capacity may be insufficient. On the other hand, when the amount of the polymerizable monomer used exceeds 99.9% by mass, the obtained porous material has insufficient strength, elastic recovery, etc., and sufficient water absorption and water absorption speed cannot be secured. There is.
[0023]
(B) Crosslinkable monomer
The crosslinkable monomer is not particularly limited as long as it has at least two polymerizable unsaturated groups in the molecule, and in the same manner as the polymerizable monomer, in a dispersed or water-in-oil type highly dispersed phase emulsion. It is not particularly limited as long as it can be polymerized and can form bubbles.
[0024]
Specific examples of the crosslinkable monomer include divinylbenzene, trivinylbenzene, divinyltoluene, divinylxylene, p-ethyl-divinylbenzene, divinylalkylbenzenes, divinylnaphthalene, divinylphenanthrene, divinylbiphenyl, and divinyldiphenylmethane. Aromatic monomers such as divinyl benzyl, divinyl phenyl ether and divinyl diphenyl sulfide; oxygen-containing monomers such as divinyl furan; sulfur-containing monomers such as divinyl sulfide and divinyl sulfone; butadiene, isoprene, pentadiene and the like Aliphatic monomer; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, octanediol di (meth) acrylate, decanediol di ( (Meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol di (Meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, N, N'-methylenebis (meth) acrylamide, isocyanuric acid triary , Triallylamine, tetraallyloxyethane, and hydroquinone, catechol, resorcinol, and ester compounds of polyhydric alcohols with acrylic acid or methacrylic acid such as sorbitol may be cited. These may be used alone or in combination of two or more.
[0025]
The amount of the crosslinkable monomer used is preferably in the range of 0.1 to 90% by mass with respect to the mass of the whole monomer component composed of the polymerizable monomer and the crosslinkable monomer. More preferably, it is 1-70 mass%, Most preferably, it is the range of 30-70 mass%. When the amount of the crosslinkable monomer used is less than 0.1% by mass, the resulting porous material has insufficient strength, elastic recovery, etc., or the amount of absorption per unit volume or unit mass is insufficient. While sufficient water absorption and water absorption speed may not be ensured, if the amount of the crosslinkable monomer used exceeds 90% by mass, the porous material may become brittle or the water absorption capacity may be insufficient.
[0026]
(C) Surfactant
The surfactant is not particularly limited as long as it can emulsify the aqueous phase in the oil phase constituting HIPE, and conventionally known nonionic surfactants, cationic surfactants, anionic surfactants , Amphoteric surfactants and the like can be used.
[0027]
Among these, nonionic surfactants include nonylphenol polyethylene oxide adducts; block polymers of ethylene oxide and propylene oxide; sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate Sorbitan fatty acid esters such as rate, sorbitan monooleate, sorbitan trioleate, sorbitan sesquioleate, sorbitan distearate; glycerol monostearate, glycerol monooleate, diglycerol monooleate, self-emulsifying glycerol monostearate, etc. Glycerin fatty acid ester; polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylenes Polyoxyethylene alkyl ethers such as allyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene nonylphenyl ether; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan Polyoxyethylene sorbitan fatty acid esters such as monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate ; Polyoxyethylene sorbitol fatty acids such as polyoxyethylene sorbitol tetraoleate Steal; Polyoxyethylene fatty acid ester such as polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate; polyoxyethylene alkylamine; polyoxyethylene hydrogenated castor oil; alkyl alkanolamide, etc. In particular, HLB is 10 or less, preferably 2-6. Among these, two or more kinds of nonionic surfactants may be used in combination, and the combined use may improve the stability of HIPE.
[0028]
Cationic surfactants include quaternary ammonium salts such as stearyl trimethyl ammonium chloride, ditallow dimethyl ammonium methyl sulfate, cetyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, alkylbenzyl dimethyl ammonium chloride, lauryl trimethyl ammonium chloride; Examples include alkylamine salts such as nutamine acetate and stearylamine acetate; alkylbetaines such as laurylbetaine, stearylbetaine, and laurylcarboxymethylhydroxyethylimidazolinium betaine; and amine oxides such as lauryldimethylamine oxide. By using a cationic surfactant, it is possible to impart excellent antibacterial properties when the resulting porous material is used as a water-absorbing material.
[0029]
As the anionic surfactant, those having an anion portion and an oil-soluble portion can be preferably used. For example, an alkyl sulfate salt such as sodium dodecyl sulfate, potassium dodecyl sulfate, ammonium alkyl sulfate, etc .; sodium dodecyl polyglycol ether sulfate; sodium Sulforicinoates; alkyl sulfonates such as sulfonated paraffin salts; alkyl sulfonates such as sodium dodecylbenzene sulfonate and alkali metal sulfates of alkali phenol hydroxyethylene; high alkyl naphthalene sulfonates; naphthalene sulfonic acid formalin condensate, sodium laurate Fatty acid salts such as rate, triethanolamine oleate, triethanolamine ahiate, etc .; polyoxy Reactions with double bonds such as alkyl ether sulfates; polyoxyethylene carboxylate sulfates, polyoxyethylene phenyl ether sulfates; dialkyl ester succinates; polyoxyethylene alkylaryl sulfates Anionic emulsifiers can be used. HIPE can be prepared by using an anionic surfactant in combination with a cationic surfactant.
[0030]
In addition, when a nonionic surfactant and a cationic surfactant are used in combination, the stability of HIPE may be improved.
[0031]
The amount of the surfactant used is preferably 1 to 30 parts by mass, more preferably 3 parts by mass with respect to 100 parts by mass of the whole monomer component composed of a polymerizable monomer and a crosslinkable monomer. -15 parts by mass. When the amount of the surfactant used is less than 1 part by mass, the high dispersibility of the HIPE may become unstable or the original function and effect of the surfactant may not be sufficiently exhibited. On the other hand, when the usage-amount of the said surfactant exceeds 30 mass parts, the porous material obtained may become too weak, the further effect corresponding to the addition exceeding this cannot be anticipated, and it is uneconomical.
[0032]
(D) Water
In addition to tap water, pure water, and ion exchange water, the above-mentioned water may be used as it is or after being subjected to a predetermined treatment from waste water obtained by producing a porous material in order to reuse waste water. it can. In the present invention, it is preferable to use treated water having a polymerization initiator concentration of 800 ppm as a result of treating wastewater. This is because wastewater can be used effectively. At this time, it is not limited to the case where the entire amount of water is treated water from which the polymerization initiator has been removed from the waste water, and may be a case where the treated water is partially used. Moreover, when it has the production line of a some porous material, after processing the wastewater obtained by one line, you may utilize this wastewater for HIPE formation of another line.
[0033]
(E) Polymerization initiator
In order to achieve HIPE polymerization in a very short time which is the object of the present invention, a polymerization initiator is used. The polymerization initiator is not particularly limited as long as it can be used in reverse emulsion polymerization, and both water-soluble and oil-soluble can be used.
[0034]
Examples of the water-soluble polymerization initiator include azo compounds such as 2,2′-azobis (2-amidinopropane) dihydrochloride; persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate; potassium peracetate, Examples thereof include peroxides such as sodium peracetate, potassium percarbonate, sodium percarbonate, and hydrogen peroxide.
[0035]
Examples of the oil-soluble polymerization initiator include cumene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxy-2-ethylhexanoate, di-t-butyl peroxide, diisopropylbenzene hydroperoxide, p-menthane hydro Examples thereof include peroxides, peroxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, benzoyl peroxide, and methyl ethyl ketone peroxide.
[0036]
These polymerization initiators may be used alone or in combination of two or more. It is preferable to use two or more polymerization initiators having different 10-hour half-life temperatures, which are temperatures at which the concentration is halved in 10 hours. Of course, it goes without saying that a water-soluble polymerization initiator and an oil-soluble polymerization initiator may be used in combination.
[0037]
The amount of the polymerization initiator that can be used in the reverse emulsion polymerization depends on the combination of the monomer component and the polymerization initiator, but the entire monomer component composed of the polymerizable monomer and the crosslinkable monomer. It is preferable that it is the range of 0.05-25 mass parts with respect to 100 mass parts of, More preferably, it is 1.0-10 mass parts. When the amount of the polymerization initiator used is less than 0.05 parts by mass, the amount of unreacted monomer components increases, and therefore the amount of residual monomers in the resulting porous material increases, which is not preferable. . On the other hand, when the usage-amount of the said polymerization initiator exceeds 25 mass parts, since control of superposition | polymerization becomes difficult or the mechanical property in the porous material obtained deteriorates, it is unpreferable.
[0038]
Furthermore, you may use the redox polymerization initiator system formed by combining the said polymerization initiator and a reducing agent. The redox polymerization initiator further includes a reducing agent in addition to the peroxide as a polymerization initiator, and the addition method is not particularly limited. For example, when a peroxide is added to a reducing agent added in advance, the redox polymerization initiator is between two components. Active red radicals are generated by a redox reaction, and polymerization is initiated. In this case, both water-soluble and oil-soluble polymerization initiators can be used, and a water-soluble redox polymerization initiator system and an oil-soluble redox polymerization initiator system may be used in combination. Specifically, the following reducing agent is used in combination with the peroxide.
[0039]
For the reducing agent that can be used in the redox polymerization initiator system, examples of the water-soluble reducing agent include sodium bisulfite, thiosulfates such as sodium thiosulfate, sodium thiosulfate, and potassium thiosulfate, dithionite and salts thereof. L-ascorbate such as L-ascorbic acid and sodium L-ascorbate, erythorbates such as erythorbic acid and sodium erythorbate, iron (II) oxalate, iron (II) sulfate, iron (II) lactate, Divalent iron salts such as iron (II) chloride and ferrous ammonium sulfate (Mole salt), copper (I) chloride, copper (I) bromide, copper (I) iodide, copper (I) sulfate, Examples thereof include monovalent copper salts such as copper oxide and copper (I) cyanide. Examples include formaldehyde, sodium formaldehyde sulfoxylate, glucose, dextrose, triethanolamine, diethanolamine, and oxalic acid. Examples of oil-soluble reducing agents include organic amine compounds such as aniline, dimethylaniline, and p-phenylenediamine, and organic acid transition metal salts such as tin octylate and cobalt naphthenate. These redox polymerization initiator-based reducing agents may be used alone or in combination of two or more.
[0040]
The content ratio (mass ratio) of the reducing agent in the case of the redox polymerization initiator system is polymerization initiator (oxidizing agent) / reducing agent = 1 / 0.01 to 1/10, preferably 1 / 0.2 to 1. / 5 or so.
[0041]
(F) Salts
The above salts may be used if necessary for improving the stability of HIPE.
[0042]
Specific examples of the salts include water-soluble salts such as alkali metals such as calcium chloride, sodium sulfate, sodium chloride and magnesium sulfate, halides of alkaline earth metals, sulfates and nitrates. These salts may be used alone or in combination of two or more. These salts are preferably added to the aqueous phase. Of these, polyvalent metal salts are preferred from the viewpoint of the stability of HIPE during polymerization.
[0043]
The amount of such salts used is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of water. If the amount of salt used exceeds 20 parts by mass, the waste water squeezed from HIPE will contain a large amount of salt, which increases the cost of treating the waste water, and expects further effects commensurate with the addition exceeding this amount. It is uneconomical. When the amount of the salt used is less than 0.1 parts by mass, there is a possibility that the effect of adding the salt cannot be sufficiently exhibited.
[0044]
(G) Other additives
Furthermore, any other various additives may be appropriately used as long as they lead to improvement of the manufacturing conditions and the performance of the obtained HIPE characteristics and porous material by adding the performance and functions of these additives. In order to adjust the pH, a base and / or a buffer may be added. About the usage-amount of these other additives, what is necessary is just to add in the range which can fully exhibit the performance and the function and also economical efficiency only for the purpose of each addition. Examples of such additives include activated carbon, inorganic powder, organic powder, metal powder, deodorant, antibacterial agent, fungicide, fragrance, various polymers, and the like.
[0045]
[II] Formation of HIPE
The method for forming HIPE is not particularly limited, and polymerization is started when the aqueous phase obtained by reducing the polymerization initiator in the wastewater obtained by dehydrating the porous crosslinked polymer is used as the aqueous phase. Conventionally known HIPE formation methods can be used as appropriate, except for using an aqueous phase in which the agent concentration is reduced to 800 ppm or less. The typical preparation method will be specifically described below.
[0046]
(A) HIPE manufacturing equipment
The HIPE forming apparatus is not particularly limited, and a conventionally known manufacturing apparatus can be used. For example, as a stirrer (emulsifier) used for mixing and stirring a water phase and an oil phase, known stirrers and kneaders can be used. Examples include propeller type, saddle type, turbine type blade agitators, homomixers, line mixers, pin mills, etc., and any of these may be used.
[0047]
(B) Mixing of HIPE materials
In general, a component constituting an oil phase containing at least a polymerizable monomer, a crosslinkable monomer and a surfactant is stirred at a predetermined temperature to prepare a uniform oil phase, and charged into an emulsifier.
[0048]
As the aqueous phase, those having a polymerization initiator content of 800 ppm or less obtained by reducing the polymerization initiator in the wastewater obtained by dehydrating the porous crosslinked polymer are used. This water phase is stirred while adding salts and other water phase constituents and water to the water phase as necessary, and heated to a predetermined temperature of 30 to 95 ° C. to prepare a uniform aqueous phase. Prepare. HIPE can be stably formed by mixing and stirring efficiently at a predetermined temperature described later, applying an appropriate shearing force, and emulsifying. You may add a 3rd component to the water phase and oil phase for HIPE formation as needed.
[0049]
In any case, in the present invention, water with a polymerization initiator content reduced to 800 ppm or less is used for HIPE formation, which prevents gelation in the emulsifier and forms HIPE smoothly. Therefore, it is preferable not to add a water-soluble polymerization initiator to the aqueous phase in advance, and it is also preferable not to add an oil-soluble polymerization initiator to the oil phase.
[0050]
(C) HIPE formation temperature
The formation temperature of HIPE (hereinafter also referred to as emulsification temperature) is in the range of 70 to 110 ° C, more preferably in the range of 80 to 110 ° C. When the HIPE formation temperature is less than 70 ° C., the heating may last longer depending on the curing temperature. On the other hand, when the HIPE formation temperature exceeds 110 ° C., the stability of the formed HIPE is poor. There is a case. For this reason, the temperature of the oil phase and / or the aqueous phase is adjusted in advance to a predetermined emulsification temperature, and stirred and mixed to emulsify, and finally HIPE in the above temperature range can be formed.
[0051]
(D) Water phase / oil phase (W / O) ratio
The water phase / oil phase (W / O) ratio (mass ratio) of the HIPE thus obtained is appropriately determined depending on the purpose of use of the porous material having open cells (for example, a water absorbing material, an oil absorbing material, a soundproof material, a filter, etc.). It can be selected and is not particularly limited, and may be 3/1 or more as defined above, preferably 10/1 to 250/1, particularly 10/1 to 100/1. In addition, when the W / O ratio is less than 3/1, the ability of the porous material to absorb water and energy is insufficient, the opening degree is low, and the opening degree of the surface of the resulting porous material is low. Therefore, there is a possibility that sufficient liquid passing performance may not be obtained. However, the pore ratio of the porous material is determined by changing the W / O ratio. Therefore, it is desirable to select the W / O ratio so that the hole ratio matches the application and purpose. For example, when used as various other absorbents such as diapers and sanitary materials, the W / O ratio is preferably about 10/1 to 100/1. The HIPE obtained by stirring and mixing the aqueous phase and the oil phase is usually a white, high-viscosity emulsion.
[0052]
[III] Production of porous crosslinked polymer
(A) Addition of polymerization initiator
The polymerization initiator is preferably added after the formation of HIPE. In the present invention, it is preferable to start the polymerization by adding a polymerization initiator to HIPE having a temperature of 70 ° C. or higher.
[0053]
Further, the polymerization initiator may be used in combination with an oxidizing agent and a reducing agent, as in the case of a redox initiator, and in this case, the polymerization is particularly promoted after mixing the two. For this reason, “adding a polymerization initiator” in the present specification means that when a polymerization initiator is used in combination with two or more compounds, the plurality of polymerization initiators are added. When a redox polymerization initiator is used as a polymerization initiator, a reducing agent is added in advance to the oil phase and / or the aqueous phase to form HIPE, the HIPE is adjusted to a predetermined temperature, and then peroxidized. It is preferable to add a product.
[0054]
In addition, the porous material can be continuously produced in a short time by increasing the emulsification temperature and the polymerization temperature, but when the emulsification temperature is high, the polymerization may be started immediately by the addition of the polymerization initiator. is there. For this reason, in this invention, the introduction path | route of a reducing agent or an oxidizing agent other polymerization initiator is provided in the path | route from the emulsifier which forms HIPE to a polymerization container or a polymerization machine, and it adds to HIPE, and mixes with a line mixer. Is preferred. This can prevent gelation in the emulsifier. At this time, the kind of the polymerization initiator added to the HIPE is not limited. Therefore, in addition to the case where an oil-soluble or water-soluble polymerization initiator is added by the route, a method of adding a water-soluble reducing agent by a route from an emulsifier to the polymerizer after adding a peroxide during HIPE formation. Are effective depending on the type of polymerization initiator used.
[0055]
The polymerization initiator can be used undiluted or in the form of a solution of water or an organic solvent, or a dispersion, etc. Especially when the polymerization initiator or the reducing agent of the redox polymerization initiator is oil-soluble. It is efficient to dissolve in an oil phase solvent, and in the case of water solubility, dissolve in an aqueous solvent and add to HIPE.
[0056]
(B) HIPE polymerization equipment
The polymerization apparatus that can be used in the present invention is not particularly limited, and for example, a belt conveyor type continuous polymerization machine equipped with a temperature adjustment apparatus, a continuous casting polymerization machine, or the like can be used. The continuous polymerization machine requires a length corresponding to the polymerization time. However, according to the method of the present invention, since the HIPE can be polymerized in a short time, the polymerization line does not become long and the apparatus can be made compact. Of course, a batch type polymerization tank or a batch type casting polymerization machine can also be used.
[0057]
(C) Polymerization method
HIPE can be polymerized by a conventionally known method. Therefore, a porous crosslinked polymer can be obtained by supplying HIPE to the polymerization apparatus and heating it.
[0058]
In the HIPE of the present invention, it is preferable to heat and polymerize the HIPE in the range of room temperature to 150 ° C. From the viewpoint of the stability and polymerization rate of the HIPE, the polymerization temperature is preferably in the range of 70 to 150 ° C, more preferably. It is 80-130 degreeC, Most preferably, it is the range of 90-110 degreeC. When the polymerization temperature is less than room temperature, the polymerization takes a long time, which is not preferable for industrial production. On the other hand, when the polymerization temperature exceeds 150 ° C., the pore diameter of the resulting porous material may become non-uniform, and the strength of the porous material may decrease, which may be undesirable. Further, the polymerization temperature may be changed in two stages or even multiple stages during the polymerization, and this polymerization method is not excluded.
[0059]
Moreover, the polymerization time of HIPE is in the range of 1 minute to 20 hours. Preferably it is within 1 hour, more preferably within 30 minutes, and most preferably in the range of 1 to 10 minutes.
When the polymerization time exceeds 20 hours, productivity may be inferior and industrially undesirable. In particular, since the polymerization is carried out after shaping, the efficiency of the polymerization tank after shaping can be improved, and the length of the polymerization apparatus can be reduced in the production of continuous sheets by shortening the polymerization time. Can be shortened. When the time is less than 1 minute, the strength of the porous material may not be sufficient. Of course, it is not excluded to employ a longer polymerization time. After the polymerization, the polymer is cooled or gradually cooled to a predetermined temperature, but is not particularly limited, and may be transferred to a post-treatment step such as dehydration or compression described below without cooling the polymerized porous material. good.
[0060]
Here, in the present invention, “polymerization time” refers to the total time from when the shaped HIPE enters the polymerization furnace until it exits the polymerization furnace. There is no particular restriction on this time in the present invention. However, the polymerization time of the HIPE of the present invention is from 1 minute to 20 hours, preferably within 1 hour. More preferably, it is within 30 minutes, most preferably 1 to 20 minutes, most preferably 1 to 10 minutes. When the polymerization time exceeds 1 hour, productivity may be inferior and industrially undesirable. When the time is less than 1 minute, the strength of the porous material may not be sufficient. Of course, it is not excluded to employ a longer polymerization curing time.
[0061]
The shape of the porous crosslinked polymer obtained by polymerizing HIPE may be a continuous sheet or a discontinuous sheet, or may be a shape obtained by individually charging HIPE into a mold and polymerizing the mold. May be. Specifically, HIPE is continuously supplied onto a traveling belt such as a structure in which the belt surface of the belt conveyor is heated by a heating device, and the HIPE is shaped into a smooth sheet on the belt. There is a way to polymerize. If the emulsion contact surface of the conveyor is smooth, a continuous sheet-like material having a desired thickness can be obtained by supplying HIPE onto the belt with a predetermined thickness. Furthermore, in order to produce a three-dimensional three-dimensional porous crosslinked polymer, it is possible to perform polymerization by injecting HIPE into a female mold having the shape, that is, cast polymerization. The casting polymerization may be a batch method as described above, or a continuous method in which the mold is continuously run.
[0062]
[IV] Preparation and use of wastewater
(A) Dehydration of porous crosslinked polymer
The porous material formed by completing the polymerization is usually dehydrated by compression, vacuum suction and a combination thereof. In general, 50 to 98% by mass of the used water is dehydrated by such dehydration, and the rest remains attached to the porous material.
[0063]
The dehydration rate is appropriately set depending on the use of the porous material. Usually, the water content may be set to 1 to 10 g or 1 to 5 g per 1 g of the porous material in a completely dried state.
[0064]
In the present invention, the waste water obtained in this dehydration step is reused for the formation of HIPE. In addition, water used for forming the aqueous phase of HIPE, moisture generated upon drying of the porous material, and the like can also be used as waste water.
[0065]
(B) Wastewater treatment method
The wastewater usually contains various raw materials used in HIPE formation, derivatives of the raw materials, and components of washing water. For the production of porous materials, a large amount of water is used at the time of HIPE formation, and waste water obtained by dehydration, etc. is generated depending on the W / O ratio of HIPE, so it is reused for the formation of HIPE. Therefore, it is necessary to particularly reduce the content of the polymerization initiator so that the HIPE can be stably formed.
[0066]
Examples of the method for removing the polymerization initiator include a method in which the polymerization initiator is thermally decomposed. For example, waste water is introduced into a storage tank and heated to a temperature of 70 ° C. or higher. Although temperature changes with kinds of polymerization initiator contained, More preferably, it is 80-180 degreeC, Most preferably, it is 90-180 degreeC. If the temperature falls below 70 ° C., the decomposition time becomes longer, which is disadvantageous because the internal volume of the storage tank must be increased. On the other hand, if the temperature exceeds 180 ° C., it is necessary to cool the HIPE for use in preparing HIPE, resulting in excessive consumption of heat energy. The decomposition time of the polymerization initiator by heating varies depending on the heating temperature, but in the above temperature range, it is generally 10 seconds to 24 hours, more preferably 10 seconds to 1 hour, particularly preferably 10 seconds to 30 minutes. It is. This is because the polymerization initiator can be sufficiently removed within this range.
[0067]
In particular, in the present invention, the temperature at which HIPE is formed is 70 to 110 ° C. For this reason, when heat treatment is performed to remove the polymerization initiator, if the temperature is set in consideration of the formation temperature, the temperature obtained by this removal treatment can be used effectively. This is advantageous in terms of heat economy.
[0068]
Moreover, as another removal method of a polymerization initiator, the method of adding a 3rd component to a polymerization initiator and making it decompose can be illustrated, for example. For example, when the polymerization initiator is a peroxide, the peroxide may remain in the wastewater depending on the amount of peroxide used and the type of the peroxide. Even in the case of polymerizing with a redox in which a peroxide and a reducing agent are combined as a polymerization initiator, the peroxide may remain in the waste water depending on the ratio of the peroxide to the reducing agent used. In these cases, the peroxide in the wastewater can be decomposed by adding a reducing agent to the wastewater. Moreover, the decomposition reaction is more economical and preferable because it is carried out rapidly at a lower temperature than when no reducing agent is added.
[0069]
As such a reducing agent, the water-soluble reducing agent and the oil-soluble reducing agent described in the section of the polymerization initiator can be used. These reducing agents may be used alone or in combination of two or more. When the reducing agent is added, the addition amount of the polymerization initiator contained in the wastewater can be reduced by this addition, and if the polymerization initiator content in the aqueous phase when forming HIPE again can be reduced to 800 ppm or less. no problem. For example, the content of the polymerization initiator contained in the wastewater is measured, and a necessary reducing agent amount may be added as appropriate.
[0070]
Moreover, as a reducing agent used when decomposing | disassembling the polymerization initiator in wastewater, there are transition metals, such as iron, copper, manganese, cobalt, nickel, and chromium, The method of contacting these transition metals and wastewater, and decomposing | disassembling There is. In this case, for example, the transition metal is used as it is, or a transition metal processed into powder, fiber, or wool is introduced into a waste water tank or a pipe of a production line, and the waste water and the transition metal are brought into contact with each other to form a polymerization initiator. To decompose.
[0071]
In addition, in this invention, it is preferable to use together the removal process of the polymerization initiator by heating, and the removal method by addition of a reducing agent.
[0072]
In the present invention, since the waste water after reducing the content of the polymerization initiator is used again for adjusting the HIPE, it is preferable to reduce the content of the polymerization initiator to 800 ppm or less. This is because, within this range, the stability of the HIPE is hardly impaired even when the treated waste water is used for the total amount of the aqueous phase for adjusting the HIPE. At this time, when a redox polymerization initiator is used as the polymerization initiator, the content of the polymerization initiator means the content of peroxide.
[0073]
On the other hand, even when the content of the polymerization initiator contained in the wastewater after the treatment exceeds 800 ppm, it is possible to add fresh water to this and use it as an aqueous phase for HIPE adjustment. The present invention uses a water phase having a polymerization initiator concentration of 800 ppm or less, more preferably 500 ppm or less, and particularly 100 ppm or less, so that HIPE is stable even when polymerizing HIPE at a high temperature of 70 ° C. or more. This is because it has been found that there is no loss of
[0074]
(C) Removal of impurities
Moreover, the porous polymer crosslinked body used as a porous material is obtained by standing-polymerizing HIPE formed by moderate stirring, and the stability of HIPE greatly affects the properties of the porous material. Wastewater may be acidic due to the reaction decomposition products contained in HIPE, for example, sodium persulfate decomposition products, and there may be impurities such as salts generated in the polymerization process. Stability may be harmed. Therefore, it is preferable to remove impurities and adjust pH in addition to the removal of the polymerization initiator.
[0075]
As impurities, there are both a water-soluble component and a water-insoluble component contained in the wastewater, which are components that are not necessary for the production of the porous material by the HIPE method. Water-soluble components include decomposition products of polymerization initiators such as sulfate ions and sulfite ions, decomposition products and oxidation products of monomers, impurities present in monomers, decomposition products and oxidation products of emulsifiers, and emulsifiers. There are organic compounds derived from impurities, etc. present in Examples of water-insoluble components include water-insoluble salts of the above ions, organic compounds that do not dissolve in water, HIPE polymer pieces, and other solid materials.
[0076]
As a method for removing impurities, for example, undesired components in wastewater are treated with an ion exchange resin, a semipermeable membrane or a hollow fiber membrane, or adsorbed with, for example, activated carbon or zeolite, or filter paper, filter cloth, There are methods such as filtration with an outer filtration membrane, removal / purification by separation by distillation or distillation. In the present invention, one or more of these may be used in combination, and the water-soluble component and the water-insoluble component may be removed simultaneously. Substances that inhibit the stability of HIPE are a water-soluble component and a water-insoluble component as described above, and among them, the influence of the water-insoluble component is significant, and removal of this will effectively improve the stability. There are methods for removing water-insoluble components such as filtration, centrifugation, and distillation. However, we found that centrifugation is efficient, especially that it is the most efficient method when applied to a continuous centrifuge. .
[0077]
Here, a known centrifuge can be used, but a continuous decanter centrifuge, a continuous tubular ultracentrifuge, a continuous deLaval type desk machine centrifuge, etc. When used, the water-insoluble matter can be efficiently and continuously removed, and the continuous decanter type centrifuge is particularly preferable as an apparatus suitable for treating a large amount of waste water. By such an impurity removal treatment, a HIPE is stabilized, and a porous material having an excellent surface state can be produced. In addition, the removal degree of impurities should just be removed from waste water to such an extent that the stability of HIPE is not inhibited.
[0078]
(D) pH adjustment
On the other hand, as a method for adjusting the pH of the wastewater to be reused, there is no particular limitation as long as the pH is adjusted by some method before the cross-linking polymerization in forming the HIPE and the cross-linking polymerization is performed thereafter. For example, a basic component is added to the wastewater to adjust the pH to 7 or more, more preferably 7 to 12, and the wastewater is used to form the emulsion, or a pH adjuster is added during the formation of the emulsion Then, the pH is adjusted to the above range.
[0079]
Wastewater often contains acidity because it contains sulfate ions, sulfite ions, unreacted substances such as polymerization initiators from persulfates that are polymerization initiators, and HIPE cannot be stably maintained. There is a case. Therefore, it is preferable to adjust the pH in order to stably maintain HIPE and improve the reuse rate of wastewater. Moreover, although the pH of the surface of the porous crosslinked polymer obtained by polymerizing HIPE varies depending on the raw materials used, it is often in the acidic region. Therefore, in order to remove the influence of the peroxide used as the polymerization initiator and the decomposition product of the reducing agent, the pH of the porous crosslinked polymer can be reduced by reusing wastewater whose pH has been adjusted to the weak alkali side in advance. Can approach the neutral range.
[0080]
As a method for adjusting the pH, specifically, it is preferable to keep the pH of water to be reused for preparing HIPE to be 7 or more or to add a buffer that can keep the pH of the aqueous phase near neutral. . In particular, a method of adding a base to waste water and adjusting the pH to a range of 7 to 12 is particularly convenient and particularly preferable.
[0081]
Such bases include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide, organic bases such as triethylamine, ethanolamine, diethanolamine, triethanolamine, dimethylaminoethanol, There is ammonia. In the present invention, when one of these is used alone, two or more may be used in combination.
[0082]
Moreover, a well-known buffer solution can be used as a buffer solution. A mixture of a salt such as phosphoric acid, boric acid, carbonic acid, acetic acid and the acid or base thereof having a composition capable of keeping the pH of the aqueous phase near neutral with a known buffer solution can be used. The pH may be adjusted before reuse, but may be appropriately adjusted when forming HIPE, for example.
[0083]
[V] Continuous production method of porous material
In the present specification, “continuous polymerization” means a step of continuously supplying a water phase and an oil phase to an emulsifier to continuously form HIPE, and the resulting HIPE is continuously passed through a polymerization zone to be porous. The step of obtaining a crosslinked polymer, the step of continuously dehydrating the obtained porous crosslinked polymer, etc. are all carried out continuously. On the other hand, in the “batch method”, appropriate amounts of an aqueous phase and an oil phase are supplied to an emulsifier, and the resulting HIPE is intermittently filled into a container to obtain a porous crosslinked polymer, which is then dehydrated. Is. At this time, it does not matter whether each step of HIPE formation, polymerization, and dehydration is performed continuously.
[0084]
The continuous polymerization method in which HIPE is continuously polymerized is a preferable method because the production efficiency is high and the effect of shortening the polymerization time can be most effectively utilized. Specifically, as a continuous polymerization method of a sheet-like porous cross-linked polymer, for example, a structure in which the belt surface of a belt conveyor is heated by a heating device is used to continuously apply HIPE on a traveling belt. There is a method of supplying and polymerizing the HIPE in a smooth sheet shape on the belt. If the emulsion contact surface of the conveyor is smooth, a continuous sheet-like material having a desired thickness can be obtained by supplying HIPE onto the belt with a predetermined thickness. Thus, this technique is extremely effective for improving productivity by continuously producing and achieving polymerization in a short time.
[0085]
Moreover, in order to produce a three-dimensional three-dimensional porous crosslinked polymer, it is possible to perform polymerization by injecting HIPE into a female mold having the shape, that is, cast polymerization. The casting polymerization may be a batch method as described above, or a continuous method in which the mold is continuously run.
[0086]
[VI] Post-processing (commercialization) process after porous material formation
(A) Compression
The porous material of the present invention can be in a form compressed to a fraction of the original thickness. The compressed sheet form or the like has a smaller volume than the original porous material, and can reduce transportation and storage costs. The compressed porous material has the property of absorbing water and returning to its original thickness when it comes into contact with a large amount of water, and has a feature that the water absorption speed is faster than that of the original thickness. From the viewpoint of transportation, stock space saving, and ease of handling, it is effective to compress to 1/2 or less of the original thickness. More preferably, it is good to compress to 1/4 or less of the original thickness.
[0087]
(B) Cleaning
For the purpose of improving the surface state of the porous material, the porous material may be washed with pure water, an aqueous solution containing any additive, or a solvent.
[0088]
(C) Drying
If necessary, the porous material obtained in the above steps may be heat-dried with hot air, microwaves, or the like, or may be humidified to adjust moisture.
[0089]
(D) Cutting
If necessary, the porous material obtained in the above steps may be cut into a desired shape and size and processed into products according to various applications.
[0090]
(E) Impregnation processing
Functionality can also be imparted by impregnating with additives such as cleaning agents, fragrances, deodorants and antibacterial agents.
[0091]
【Example】
Hereinafter, examples of the present invention will be described in detail. In this example, the performance of the porous crosslinked polymer was measured and evaluated as follows.
[0092]
<Surface condition of porous crosslinked polymer>
The fine uniformity of the surface of the polymerized porous crosslinked polymer was observed and evaluated at 50 times using SEM.
[0093]
<Compressive strength>
The uniaxial (in the thickness direction) compressive strength was measured at 24 ° C. using an Instron testing machine (manufactured by Instron; trade name Instron 1186-RE5500) and converted to the international unit system (kPa).
[0094]
<Viscosity stability evaluation>
About the viscosity stability of the emulsion in an emulsification process, the viscosity immediately after emulsification and the viscosity after 5 minutes were measured using the helicopter viscometer, and it was evaluated whether there was any increase in viscosity.
[0095]
250 parts by mass of HIPE immediately after emulsification was collected in a polypropylene cup having an inner diameter of 80 mm and a height of 100 mm using a helipath-type viscometer (manufactured by Brookfield, Inc .: trade name Digital Rheometer DV-III, T-shaped spindle A type). The viscosity was measured at a rotational speed of 100 rpm. The measurement temperature was measured at the same temperature as the HIPE formation temperature.
[0096]
<Quantification method of the amount of polymerization initiator>
The iodine titration method was used to determine the amount of the polymerization initiator in the wastewater.
First, 100 g of waste water was put into an iodine number flask, and 0.1 g of potassium iodide was added. Thereafter, the flask was sealed and sufficiently stirred, and then left in a cool dark place for 18 hours. After 18 hours, the mixture was taken out from a cool dark place, added with 2 to 3 ml of 1% starch aqueous solution, titrated with 0.01 mol / L sodium thiosulfate, and adjusted until the purple color disappeared (Aml). The amount of residual polymerization initiator was calculated from the following formula.
[0097]
[Expression 1]

[0098]
<Measurement of polymerization rate>
1.0 g of the porous cross-linked polymer obtained after the polymerization was added to 200 g of methylene chloride, stirred for 2 hours, filtered, and the filtrate was GC-14 manufactured by Shimadzu Corporation, Liquid Phase TC-1 (GL Science Inc. 30 m × 0.53 mm × 1.5 μm) was analyzed by gas chromatography to determine the amount of residual monomer in the porous crosslinked polymer. Using helium gas as a carrier, injection temperature = 210 ° C., detector temperature = 220 ° C., column temperature held at 40 ° C. for 10 minutes, then 20 ° C./min. For 3 minutes and 5 ° C./min. For 14 minutes and then 20 ° C./min. The temperature was raised to 200 ° C. The percentage of the residual monomer amount when the monomer amount supplied for the adjustment of HIPE was converted to 100 was calculated, and the polymerization rate was calculated using the following equation.
[0099]
[Expression 2]

[0100]
(Production Example 1)
5.1 parts by mass of 2-ethylhexyl acrylate (hereinafter, simply referred to as “parts”), 3.1 parts of 42% divinylbenzene (the other component is p-ethyl-vinylbenzene), 1.6-hexanediol diacrylate 1 .1 part monomer component, 0.6 part glycerin monooleate as a surfactant, 0.1 part ditallowdimethylammonium methyl sulfate are added and dissolved uniformly to obtain an oil phase mixture solution (hereinafter, (Referred to as “oil phase”). On the other hand, 18 parts of calcium chloride was dissolved in 425 parts of ion-exchanged water to prepare an aqueous phase aqueous solution (hereinafter referred to as “aqueous phase”) and heated to 95 ° C. The oil phase and the aqueous phase were continuously fed into the stirring mixer which is an emulsifier at the above ratio to continuously form HIPE. The ratio of the water phase to the oil phase was 44.3 / 1. The results of the viscosity stability evaluation of the emulsion are shown in Table 1. In Table 1, “Residual polymerization initiator amount (ppm) in the aqueous phase” is ppm by mass of the residual polymerization initiator amount contained in the aqueous phase used for forming the emulsion when forming the emulsion.
[0101]
The obtained HIPE was continuously extracted from the stirring mixer, heated to 95 ° C. in advance, and supplied to a static mixer equipped with a heating and heat retaining member. Separately, a solution obtained by dissolving 0.5 part of sodium persulfate as a water-soluble polymerization initiator in 6 parts of ion-exchanged water was fed from the entrance of the static mixer, and HIPE and the polymerization initiator were continuously mixed. As a result, the ratio of the water phase to the oil phase finally became 45/1.
[0102]
This HIPE is conveyed through a flexible tube, heated to 95 ° C. and continuously on a belt that runs horizontally at a speed of 0.8 to 1.5 m / min. Supplied and molded. Subsequently, a polymerization zone in which the polymerization temperature was controlled to 95 ° C. was passed for 10 minutes. After passing through the polymerization zone, it was immediately dehydrated and compressed to obtain a porous material (1) and waste water (1).
[0103]
(Production Example 2)
5.1 parts by weight of 2-ethylhexyl acrylate (hereinafter, simply referred to as “parts”), 3.1 parts of 42% divinylbenzene (the other component is p-ethyl-vinylbenzene), 1,6-hexanediol diacrylate 1 .1 part monomer component, 0.6 part glycerin monooleate as a surfactant, 0.1 part ditallowdimethylammonium methyl sulfate are added and dissolved uniformly to obtain an oil phase mixture solution (hereinafter, (Referred to as “oil phase”). On the other hand, 18 parts of calcium chloride was dissolved in 432 parts of ion-exchanged water to prepare an aqueous phase and heated to 95 ° C. The oil phase and the aqueous phase were continuously fed into the stirring mixer as an emulsifier at the above ratio to continuously form an emulsion (HIPE). The ratio of water phase to oil phase was 45/1. Regarding the viscosity stability evaluation of the emulsion, the viscosity immediately after emulsification was 987 mPa · sec, and the viscosity after 5 minutes was 992 mPa · sec.
[0104]
The obtained HIPE was continuously extracted from the stirring mixer, heated to 95 ° C. in advance, and supplied to a static mixer equipped with a heating and heat retaining member. Separately, 0.22 part of t-butylperoxy-2-ethylhexanoate as an oil-soluble polymerization initiator was sent from the entrance of the static mixer, and HIPE and the polymerization initiator were continuously mixed. As a result, the ratio of the water phase to the oil phase finally became 45/1.
[0105]
This HIPE is conveyed through a flexible tube, heated to 95 ° C. and continuously on a belt that runs horizontally at a speed of 0.8 to 1.5 m / min. Supplied and molded. Subsequently, a polymerization zone in which the polymerization temperature was controlled to 95 ° C. was passed for 10 minutes. After passing through the polymerization zone, it was immediately dehydrated and compressed to obtain a porous material (2) and waste water (2).
[0106]
(Production Example 3)
Monomer component consisting of 5.1 parts of 2-ethylhexyl acrylate, 3.1 parts of 42% divinylbenzene (the other component is p-ethyl-vinylbenzene), 1.1 parts of 1,6-hexanediol diacrylate, interface An oil phase was prepared by adding 0.6 parts of glycerin monooleate and 0.1 part of ditallowdimethylammonium methyl sulfate as activators and dissolving uniformly. On the other hand, 18 parts of calcium chloride was dissolved in 432 parts of ion-exchanged water to prepare an aqueous phase and heated to 95 ° C.
[0107]
The oil phase and the aqueous phase were continuously fed into the stirring mixer which is an emulsifier at the above ratio to continuously form HIPE. The ratio of water phase to oil phase was 45/1. Regarding the viscosity stability evaluation of the emulsion, the viscosity immediately after emulsification was 880 mPa · sec, and the viscosity after 5 minutes was 879 mPa · sec.
[0108]
The obtained HIPE was continuously extracted from the stirring mixer, heated to 95 ° C. in advance, and supplied to a static mixer equipped with a heating and heat retaining member. A liquid obtained by dissolving 0.5 part of sodium persulfate in 6 parts of ion exchange water as a polymerization initiator was fed separately from the inlet of the static mixer, and HIPE and the polymerization initiator were continuously mixed. As a result, the ratio of the water phase to the oil phase finally became 45/1.
[0109]
This HIPE is conveyed through a flexible tube, heated to 95 ° C. and continuously on a belt that runs horizontally at a speed of 1.6 to 3.0 m / min. Supplied and molded. Subsequently, a polymerization zone in which the polymerization temperature was controlled to 95 ° C. was passed in about 5 minutes. After passing through the polymerization zone, it was immediately dehydrated and compressed to obtain a porous material (24) and waste water (3).
[0110]
Example 1
500 parts of the waste water (1) obtained in Production Example 1 was collected in a separable flask and heated at 100 ° C. under reflux. After the water temperature reached 90 ° C., 0.29 parts of sodium bisulfite was subsequently added, and the mixture was heated for 30 minutes to obtain treated water (1). The amount of residual polymerization initiator was not detected in the treated water (1).
[0111]
A viscosity stability evaluation HIPE was formed from the same oil phase as in Production Example 1 using treated water (1). 443 parts of treated water (1) was continuously fed into the stirring mixer in the oil phase and aqueous phase of Production Example 1 to continuously form HIPE. The ratio of water phase to oil phase was 44.3 / 1. 250 parts of the obtained emulsion was taken out and evaluated for viscosity stability. The results of viscosity stability evaluation are shown in Table 1.
[0112]
A porous material (3) was obtained in the same manner as in Production Example 1 except that treated water (1) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (3).
[0113]
(Example 2)
Treated water (2) was obtained by the same operation as in Example 1 except that heating was performed for 10 minutes after the addition. The amount of residual polymerization initiator in the treated water (2) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (2).
[0114]
A porous material (4) was obtained in the same manner as in Production Example 1, except that treated water (2) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (4).
[0115]
(Example 3)
Treated water (3) was obtained by the same operation as in Example 1 except that heating was performed for 5 minutes after the addition. The amount of residual polymerization initiator in the treated water (3) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (3).
[0116]
A porous material (5) was obtained in the same manner as in Production Example 1, except that treated water (3) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (5).
[0117]
Example 4
Treated water (4) was obtained in the same manner as in Example 1 except that 0.38 part of sodium bisulfite was added and heated for 5 minutes after the addition. The amount of residual polymerization initiator in the treated water (4) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (4).
[0118]
A porous material (6) was obtained in the same manner as in Production Example 1, except that treated water (4) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (6).
[0119]
(Example 5)
Treated water (5) was obtained in the same manner as in Example 1, except that 0.19 part of sodium bisulfite was added and heated for 30 minutes after the addition. The amount of the remaining polymerization initiator in the treated water (5) was 80 ppm. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (5).
[0120]
A porous material (7) was obtained in the same manner as in Production Example 1, except that treated water (5) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (7).
[0121]
(Example 6)
500 g of waste water (1) obtained in Production Example 1 was collected in a separable flask and heated at 100 ° C. under reflux. After the water temperature reached 90 ° C., 0.64 part of L-ascorbic acid was subsequently added and heated for 10 minutes after addition to obtain treated water (6). The amount of residual polymerization initiator in the treated water (6) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (6).
[0122]
A porous material (8) was obtained in the same manner as in Production Example 1, except that treated water (6) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (8).
[0123]
(Example 7)
The same operation was carried out except that 0.32 part of L-ascorbic acid was added in Example 6 to obtain treated water (7). The amount of the residual polymerization initiator in the treated water (7) was 50 ppm. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (7).
[0124]
A porous material (9) was obtained in the same manner as in Production Example 1 except that treated water (7) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (9).
[0125]
(Example 8)
The same operation was carried out except that 0.32 part of D-ascorbic acid was added in Example 6 to obtain treated water (7). The amount of residual polymerization initiator in the treated water (8) was 60 ppm. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (8).
[0126]
A porous material (10) was obtained in the same manner as in Production Example 1, except that treated water (8) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (10).
[0127]
Example 9
The treated water (1) obtained in Example 1 was adjusted to pH 7 with stirring with calcium hydroxide. Then, the treated water (9) was obtained by filtering a deposit. The amount of residual polymerization initiator in the treated water (9) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (9).
[0128]
A porous material (11) was obtained in the same manner as in Production Example 1 except that treated water (9) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (11).
[0129]
(Example 10)
Except having used treated water (3), the same operation as Example 9 was performed and the treated water (10) was obtained. The amount of residual polymerization initiator in the treated water (10) was not detected. The viscosity stability evaluation results of HIPE using treated water (10) are shown in Table 1.
[0130]
A porous material (12) was obtained in the same manner as in Production Example 1, except that treated water (10) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (12).
[0131]
(Example 11)
Except having used the treated water (4), the same operation as Example 9 was performed and the treated water (11) was obtained. The amount of residual polymerization initiator in the treated water (11) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (11).
[0132]
A porous material (13) was obtained in the same manner as in Production Example 1, except that treated water (11) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (13).
[0133]
(Example 12)
Except having used the treated water (6), the same operation as Example 9 was performed and the treated water (12) was obtained. The amount of residual polymerization initiator in the treated water (12) was not detected. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (12).
[0134]
A porous material (14) was obtained in the same manner as in Production Example 1, except that treated water (12) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (14).
[0135]
(Example 13)
Except having used the treated water (7), the same operation was performed in Example 9 and the treated water (13) was obtained. The amount of residual polymerization initiator in the treated water (13) was 45 ppm. Table 1 shows the viscosity stability evaluation results of HIPE using treated water (13).
[0136]
A porous material (15) was obtained in the same manner as in Production Example 1, except that treated water (13) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (15).
[0137]
(Example 14)
Except having used the treated water (8), the same operation was performed in Example 9 and the treated water (14) was obtained. The amount of residual polymerization initiator in the treated water (14) was 50 ppm. The viscosity stability evaluation results of HIPE using treated water (14) are shown in Table 1.
[0138]
A porous material (16) was obtained in the same manner as in Production Example 1, except that treated water (14) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (16).
[0139]
(Example 15)
The waste water (1) obtained in Production Example 1 was heated under pressure at 150 ° C. for 3 minutes in an autoclave to obtain treated water (12). The amount of residual polymerization initiator in the treated water (15) was not detected. The viscosity stability evaluation results of HIPE using treated water (15) are shown in Table 1.
[0140]
A porous material (17) was obtained in the same manner as in Production Example 1 except that treated water (15) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (17).
[0141]
(Example 16)
A porous material (18) was obtained in the same manner as in Production Example 1 except that waste water (2) was used as the aqueous phase for preparing HIPE in Production Example 1. Table 1 shows the physical properties of the porous material (18).
[0142]
(Example 17)
A porous material (19) was obtained in the same manner as in Production Example 2, except that waste water (2) was used as the aqueous phase for HIPE preparation in Production Example 2. Table 1 shows the physical properties of the porous material (19).
[0143]
(Example 18)
To 400 parts of the treated water (1) obtained in Example 1, 1.7 parts of calcium chloride and 41.3 parts of ion exchange water were uniformly added and dissolved to obtain treated water (16).
[0144]
The amount of residual polymerization initiator in the treated water (16) was below the detection limit as in the treated water (1). HIPE for viscosity stability evaluation was formed from the same oil phase as in Production Example 1 using treated water (16). 443 parts of treated water (16) was continuously fed into the stirred mixer in the oil phase and aqueous phase of Production Example 1 to continuously form HIPE. The ratio of water phase to oil phase was 44.3 / 1. 250 parts of the obtained emulsion was taken out and viscosity stability was evaluated. The results of viscosity stability evaluation are shown in Table 1.
[0145]
Next, a porous material (20) was obtained in the same manner as in Production Example 1, except that treated water (16) was used as the aqueous phase for HIPE adjustment in Production Example 1. Table 1 shows the physical properties of the porous material (20).
[0146]
(Example 19)
To 400 parts of the treated water (9) obtained in Example 9, 1.7 parts of calcium chloride and 41.3 parts of ion-exchanged water were uniformly added and dissolved to obtain treated water (17). The amount of residual polymerization initiator in the treated water (17) was below the detection limit as in the treated water (9).
[0147]
A HIPE for viscosity stability evaluation was formed from the same oil phase as in Production Example 1 using treated water (17). 443 parts of treated water (17) was continuously fed into the stirring mixer to the oil phase and water phase of Production Example 1 to continuously form HIPE. The ratio of water phase to oil phase was 44.3 / 1. 250 parts of the obtained emulsion was taken out and viscosity stability was evaluated. The results of viscosity stability evaluation are shown in Table 1.
[0148]
Except having used treated water (17) as a water phase for HIPE adjustment in manufacture example 1, the same operation as manufacture example 1 was performed and porous material (21) was obtained. Table 1 shows the physical properties of the porous material (21).
[0149]
(Example 20)
Waste water (1) was heated at 80 ° C. for 30 minutes to obtain treated water (18). The amount of the residual polymerization initiator in the treated water (18) was 620 ppm. Using the treated water (18), the same operation as in Example 1 was performed to evaluate the viscosity stability. The viscosity stability evaluation results are shown in Table 1. Except changing the aqueous phase of Example 1 into treated water (18), the same operation as in Example 1 was performed to obtain a porous material (22). Table 1 shows the physical properties of the porous material (22).
[0150]
(Example 21)
500 parts of the waste water (3) obtained in Production Example 3 was collected in a separable flask and heated at 100 ° C. under reflux. After the water temperature reached 90 ° C., 1.2 parts of iron (II) sulfate heptahydrate was added and mixed. After 2 minutes, calcium hydroxide was added and neutralized by adding 0.3 part. After neutralization, it was filtered through a 0.2 μm filter to obtain treated water (19). No residual polymerization initiator was detected in the treated water (19).
[0151]
443 parts of treated water (19) of the same oil phase as in Production Example 1 was continuously fed into the stirring mixer to continuously form HIPE. The ratio of water phase to oil phase was 44.3 / 1. 250 parts of the obtained emulsion was taken out and evaluated for viscosity stability. The results of viscosity stability evaluation are shown in Table 1. A porous material (23) was obtained in the same manner as in Production Example 1 except that treated water (19) was used as the aqueous phase for HIPE adjustment in Production Example 1.
[0152]
(Comparative Example 1)
A comparative porous material (1) was obtained by performing the same operation as in Production Example 1 except that waste water (1) was used as the aqueous phase for HIPE adjustment used in Production Example 1. Table 1 shows the physical properties of the comparative porous material (1).
[0153]
Moreover, the same operation as Example 1 was performed using waste water (1), and viscosity stability evaluation was performed. The viscosity stability evaluation results are shown in Table 1.
[0154]
(Comparative Example 2)
The waste water (1) was heated at 60 ° C. for 30 minutes to obtain comparative treated water (1). The amount of the residual polymerization initiator in the comparative treated water was 880 ppm. The viscosity stability evaluation was performed by performing the same operation as Example 1 using the comparison process water (1). The viscosity stability evaluation results are shown in Table 1.
[0155]
A comparative porous material (2) was obtained by performing the same operation as in Example 1 except that the aqueous phase of Example 1 was changed to comparatively treated water (1). Table 1 shows the physical properties of the comparative porous material (2).
[0156]
[Table 1]

[0157]
【The invention's effect】
According to the present invention, waste water can be effectively used. Moreover, HIPE can be formed at high temperatures by using waste water after reducing the content of the polymerization initiator as an aqueous phase for adjusting HIPE, and using an aqueous phase having a polymerization initiator concentration of 800 ppm or less, and at high temperatures. It can be polymerized stably. Moreover, since the polymerization temperature of HIPE at this time is stable even at a high temperature of 70 ° C. or higher, the subsequent polymerization time can be shortened. For this reason, a porous material can be manufactured efficiently. Moreover, the obtained porous material is excellent in compressive strength.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing a typical embodiment of a suitable continuous polymerization apparatus in the method for producing a porous material of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 ... HIPE, 102 ... Porous crosslinked polymer, 102 '... Porous material, 119 ... HIPE supply part, 201 ... Endless belt type conveyor (with drive conveyance apparatus), 203, 205 ... Sheet material, 207, 208 ... Unwinding roller,
209, 211 ... rotating roller, 212, 213 ... winding roller,
215 ... polymerization furnace, 217 ... heating temperature raising means, 219 ... heating temperature raising means,
301: Compression roll, 302, 403, 405 ... Conveyor roll for conveyance,
DESCRIPTION OF SYMBOLS 303 ... Dehydration apparatus, waste water ... 304, 310 ... Waste water treatment apparatus, 401 ... Endless band knife type slicer, 402 ... Band knife, 501 ... Oil phase, 502 ... Water phase, 503 ... Emulsifier.

Claims (5)

A porous material comprising a step of forming and polymerizing a water-in-oil highly dispersed phase emulsion containing a polymerizable monomer to obtain a porous crosslinked polymer, and a step of dehydrating the porous crosslinked polymer to obtain waste water In the production method of the present invention, the polymerization initiator contained in the wastewater is reduced by adding a reducing agent to the wastewater, and the water-in-oil is used using an aqueous phase containing the wastewater and having a polymerization initiator content of 800 ppm or less. A method for producing a porous material, characterized in that a highly dispersed phase emulsion is formed and further polymerized at a temperature of 70 ° C. or higher. Water type high internal phase emulsion oil, is to polymerization at a temperature 70 to 150 ° C., the manufacturing method according to claim 1. The formation process of water-in-oil type highly dispersed phase emulsion, the polymerization process of porous cross-linked polymer that polymerizes the emulsion, the adjustment process of waste water by dehydration of porous cross-linked polymer, and the polymerization initiator contained in the waste water are reduced and a step of, in which respective steps are continuously carried out, method according to claim 1 or 2. The production method according to claim 3 , wherein the production step of the porous crosslinked polymer is carried out within 30 minutes. The manufacturing method in any one of Claims 1-4 which has two or more production lines of a porous material, and uses the waste water obtained with one production line with another production line.

Images