JP4428898B2 - Vinyl alcohol polymer and process for producing the same - Google Patents

Description

（ｘ＝０〜３，ｙ＝０〜１，ｚ＝１〜５の整数、Ｒ_１．Ｒ_２は水素原子、メチル基又はエチル基、Ｒ_３は水素原子、水酸基、メチル基、エチル基、メトキシ基又はエトキシ基を示す。）
【０００８】
【発明の実施の形態】
以下、本発明を詳細に説明する。
【０００９】
本発明のビニルアルコール系重合体は、ビニルアルコール構造単位を主体とし、下記の化３で表される構造単位を０．１〜１５モル％含有するものであって、このほかの構造として、未ケン化のビニルエステル単位、ジアセトンアクリルアミド単位などを包含することができる。
【００１０】
【化３】

（ｘ＝０〜３，ｙ＝０〜１，ｚ＝１〜５の整数、Ｒ_１．Ｒ_２は水素原子、メチル基又はエチル基、Ｒ_３は水素原子、水酸基、メチル基、エチル基、メトキシ基又はエトキシ基を示す。）
【００１１】
本発明のビニルアルコール系重合体は、まず、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体を作製し、メタノール溶剤の存在下で、前記の共重合体にアミノ基を有するシランカップリング剤を反応せしめた後、ケン化するか、あるいはジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体をケン化した後に、メタノール溶剤の存在下で、アミノ基を有するシランカップリング剤を反応せしめることによって製造することができ、いずれの製造方法の場合でも、シランカップリング剤のアミノ基とジアセトンアクリルアミド単位が反応することによって本発明のビニルアルコール系重合体を得ることができる。
【００１２】
前記のジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体の製造に使用する脂肪酸ビニルエステルとしては、蟻酸ビニル、酢酸ビニル、プロピオン酸ビニル、バーサチック酸ビニル等が挙げられ、中でも酢酸ビニルが工業的に最も好ましい。
【００１３】
ジアセトンアクリルアミドと脂肪酸ビニルエステルとの共重合方法としては、ビニルエステル系重合体の製造法において従来より公知のバルク重合、溶液重合、エマルジョン重合、懸濁重合等の各種の重合方法を用いることができ、中でもメタノールを溶剤として用いる溶液重合が工業的に好ましい。
【００１４】
本発明で使用されるジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体は、本発明の効果を阻害しない範囲で、ジアセトンアクリルアミドまたは脂肪酸ビニルエステルと共重合可能な、例えばクロトン酸、アクリル酸、メタクリル酸などの不飽和モノカルボン酸およびそのエステル・塩・無水物・アミド・ニトリル類、マレイン酸、イタコン酸、フマル酸などの不飽和ジカルボン酸およびその塩、マレイン酸モノメチル、イタコン酸モノメチル等の不飽和二塩基酸モノアルキルエステル類、炭素数２〜３０のα−オレフィン類、アルキルビニルエーテル類、ビニルピロリドン類、３−（メタ）アクリルアミドプロピルトリメトキシシラン、３−（メタ）アクリルアミドプロピルトリエトキシシラン、３−（メタ）アクリルアミドプロピルトリ（β−メトキシエトキシ）シラン、３−（メタ）アクリルアミドプロピル（Ｎ−メチルアミノエトキシシラン）、２−（メタ）アクリルアミドエチルトリメトキシシラン、１−（メタ）アクリルアミドメチルトリメトキシシラン、２−（メタ）アクリルアミド−２−メチルプロピルトリメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、ビニルトリス（β−メトキシエトキシ）シラン等のアルコキシシリル基を有する単量体とともに共重合したものであっても良い。
【００１５】
ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体におけるジアセトンアクリルアミド単位の含有量は、０．１〜１５モル％であり、好ましくは１〜１０モル％である。ジアセトンアクリルアミド単位が０．１モル％未満の場合には、付加されるアミノ基を有するシランカップリング剤が少なくなり、最終的に得られるビニルアルコール系重合体のシリカ化合物に対する結着性が低く、一方１５モル％を超えて多くしてもシリカ化合物に対する結着性が変わらず、製造コストが高くなるという点で不利である。
【００１６】
ケン化前にジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体とアミノ基を有するシランカップリング剤とを反応せしめる方法としては、該共重合体のメタノール溶液にアミノ基を有するシランカップリング剤を添加し、室温又は高温で攪拌、混合する方法が挙げられる。
【００１７】
ここで使用されるアミノ基を有するシランカップリング剤を例示すると、例えば、Ｎ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリエトキシシラン、γ−アミノプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、γ−アミノプロピルメチルジエトキシシラン等が挙げられ、これらの１種または２種以上を組み合わせて使用することもできる。
【００１８】
また、アミノ基を有するシランカップリング剤の添加量としては、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体に対して０．１〜１５モル％に相当する量であり、好ましくは１〜１０モル％に相当する量である。アミノ基を有するシランカップリング剤の添加量が少なく、前記の共重合体に対して０．１モル％未満では、最終的に得られるビニルアルコール系重合体のシリカ化合物に対する結着性が低く、一方、１５モル％を越えて多くしてもシリカ化合物に対する結着性が変わらず、製造コストが高くなるという点で不利である。また、アミノ基を有するシランカップリング剤の添加量は前記の共重合体中のジアセトンアクリルアミド単位の含有量以上に添加してもシリカ化合物に対する結着性が向上せず、製造コストが高くなるという点で不利である。
【００１９】
また、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体にアミノ基を有するシランカップリング剤を反応せしめた重合体のケン化方法は、従来より公知の脂肪酸ビニルエステル共重合体のアルカリケン化および酸ケン化方法を適用することができ、中でも重合体のメタノール溶液またはメタノールと水、酢酸メチル、ベンゼン等の混合溶液に水酸化アルカリを添加して加アルコール分解する方法が工業的に好ましい。
【００２０】
一方、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体のケン化物とアミノ基を有するシランカップリング剤とを反応せしめる方法としては、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体にアミノ基を有するシランカップリング剤を添加せず、前記の脂肪酸ビニルエステル系重合体のケン化方法でケン化、粉砕した後、メタノール溶剤中に浸漬し、アミノ基を有するシランカップリング剤を添加し、室温又は高温で攪拌する方法が挙げられる。
【００２１】
その際、前記のアミノ基を有するシランカップリング剤を使用することができ、添加量も前記と同じく、ジアセトンアクリルアミド−脂肪酸ビニルエステル共重合体のケン化物に対して０．１〜１５モル％に相当する量である。
【００２２】
ケン化前およびケン化後にアミノ基を有するシランカップリング剤を反応せしめたビニルアルコール系重合体の重合度、ケン化度は特に制限はないが、ケン化度が８０モル％以上、重合度は５０〜４０００が好ましい。
【００２３】
ケン化前およびケン化後にアミノ基を有するシランカップリング剤を反応せしめる場合においても、反応系にメタノールが存在する必要があり、メタノール以外の溶剤中では反応が極めて遅く、目的とするビニルアルコール系重合体を簡易に得ることができない。その反応の際に、メタノール以外の例えば水、エタノール、エーテル、ベンゼン等の溶剤が共存していてもかまわないが、溶剤中のメタノール比率が高い程、前記反応の際の速度が高く、好ましい。
【００２４】
本発明のビニルアルコール系重合体は水溶性であり、使用に際して水溶液として調製される。その調製方法としては、特に制限はないが、本発明のビニルアルコール系重合体の水溶液を作製する際、必要に応じてデンプン、メチルセルロース、カルボキシメチルセルロース等のセルロース誘導体、ポリアクリル酸誘導体、ゼラチン等の他の天然高分子、合成高分子、クレー、カオリン、タルク、シリカ、炭酸カルシウム等の無機充填剤、グリセリン、ソルビトール等の可塑剤、界面活性剤、消泡剤、帯電防止剤、キレート剤、架橋剤等を本発明の効果を損なわない範囲で配合することができる。
【００２５】
【実施例】
次に、実施例により本発明を具体的に説明する。
実施例または比較例で得られたビニルアルコール系重合体の評価は以下の方法で行った。
【００２６】
▲１▼．シリカ蒸着フィルムへの密着性の評価
得られたビニルアルコール系重合体の５質量％水溶液を作製し、シリカ蒸着処理を行ったポリエチレンテレフタレートフィルム（厚み１２μｍ）の蒸着面に流延し、２０℃，６５％ＲＨの条件下で２４時間乾燥し、約５０μｍの厚みの塗膜を形成した。
上記のビニルアルコール系重合体の塗膜を有するシリカ蒸着フィルムを１００ｍｍ×２０ｍｍの大きさに切断し、東洋精機製ストログラフにて、２０ｍｍ幅の塗膜とシリカ蒸着フィルムとの剥離強度を測定した。
【００２７】
▲２▼．粒子状シリカに対するバインダー力の評価
得られたビニルアルコール系重合体の５質量％水溶液を作製し、この水溶液１００質量部に粒子状シリカ２０質量部、純水５０質量部を加え、ホモミキサー（攪拌速度：１００００ｒｐｍ）を使用して室温で５分間攪拌し、塗工液を調製した。
前記の塗工液をコピー用紙（リコー製、マイリサイクルペーパーニュー）上にＮｏ．４０のバーコーターを使用して約１０ｇ／ｍ^２（固形分）になるように塗工し、ドラム式乾燥機を用いて１０５℃で１２０秒間乾燥を行った。
得られた塗工紙にニチバン製セロハン粘着テープ（幅：１８ｍｍ）を貼り付け、東洋精機製ストログラフにて剥離強度を測定し、塗工層のバインダー力を評価した。
【００２８】
▲３▼．総合評価
上記のシリカ蒸着フィルムに対する密着性、粒子状シリカに対するバインダー力の各評価結果を総合して、シリカ化合物に対する結着性を以下の基準で評価した。
◎：シリカ化合物に対する結着性が非常に優れている。
○：シリカ化合物に対する結着性が優れており、実用レベルにある。
×：シリカ化合物に対する結着性が実用レベルに達していない。
【００２９】
ジアセトンアクリルアミド−酢酸ビニル共重合体の合成例
合成例１
攪拌機、温度計、滴下ロートおよび還流冷却器を取り付けたフラスコ中に、酢酸ビニル６７２質量部、ジアセトンアクリルアミド１０質量部、およびメタノール１７８質量部を仕込み、系内の窒素置換を行った後、内温を６０℃まで昇温した。この系に２，２′−アゾビスイソブチリロニトリル１質量部をメタノール５０質量部に溶解した溶液を添加し、重合を開始した。重合開始後、５時間かけて、ジアセトンアクリルアミド５５質量部をメタノール３５質量部に溶解した溶液を一定速度で滴下し、６時間後に冷却し、重合を停止した。重合収率は７８％であった。得られた反応混合物にメタノール蒸気を加えながら残存する酢酸ビニルを留出し、ジアセトンアクリルアミド共重合成分を含有する酢酸ビニル系重合体の５０質量％メタノール溶液を得た。表１に示すように、この樹脂中のジアセトンアクリルアミド単位の含有率は、元素分析測定により５．０モル％であり、重合度は１６８０であった。
【００３０】
合成例２〜３、比較合成例１〜２
前記の方法に準じて酢酸ビニルとジアセトンアクリルアミドとを共重合し、ジアセトンアクリルアミド単位の含有量および重合度の異なる３種類の酢酸ビニル系重合体およびジアセトンアクリルアミドを使用しない未変性ポリ酢酸ビニル１種類を得た。これらの樹脂の変性度、重合度についてのデータを表１に示す。
【００３１】
【表１】

【００３２】
実施例１
合成例１で得られた酢酸ビニル系重合体（重合度：１６８０，変性度：５．０モル％）の５０％メタノール溶液１００質量部にγ−アミノプロピルトリメトキシシラン５．０質量部（酢酸ビニル系重合体に対して５．０モル％）を添加し、室温で混合攪拌した後、水酸化ナトリウムの４質量％メタノール溶液１質量部を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥して、ケン化度９８．５モル％のビニルアルコール系重合体を得た。
【００３３】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するハインダー力を評価した。表２に示すように、密着性、ハインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００３４】
実施例２
合成例１で得られた酢酸ビニル系重合体（重合度：１６８０，変性度：５．０モル％）の５０質量％メタノール溶液１００質量部にＮ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン３．７質量部（酢酸ビニル系重合体に対して３．０モル％）を添加し、室温で混合攪拌した後、水酸化ナトリウムの４％メタノール溶液１質量部を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥して、ケン化度９８．４モル％のビニルアルコール系重合体を得た。
【００３５】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００３６】
実施例３
合成例２で得られた酢酸ビニル系重合体（重合度：１４９０，変性度：１０．５モル％）の５０質量％メタノール溶液１００質量部にＮ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン１０．９質量部（酢酸ビニル系重合体に対して１０．０モル％）を添加し、室温で混合攪拌した後、水酸化ナトリウムの４質量％メタノール溶液１．５質量部を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥して、ケン化度９８．４モル％のビニルアルコール系重合体を得た。
【００３７】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、ハインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００３８】
実施例４
合成例２で得られた酢酸ビニル系重合体（重合度：１４９０，変性度：１０．５モル％）の５０質量％メタノール溶液１００質量部にＮ−β（アミノエチル）γ−アミノプロピルトリエトキシシラン５．６質量部（酢酸ビニル系重合体に対して４．０モル％）を添加し、室温で混合攪拌した後、水酸化ナトリウムの４質量％メタノール溶液１．０質量部を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥して、ケン化度８８．４モル％のビニルアルコール系重合体を得た。
【００３９】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力に評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００４０】
実施例５
合成例３で得られた酢酸ビニル系重合体（重合度：６５０，変性度：１．２モル％）の５０質量％メタノール溶液１００質量部にγ−アミノプロピルトリメトキシシラン１．０質量部（酢酸ビニル系重合体に対して１．０モル％）を添加し、室温で混合攪拌した後、水酸化ナトリウムの４質量％メタノール溶液１．０質量部を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥して、ケン化度９８．５モル％のビニルアルコール系重合体を得た。
【００４１】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力に評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００４２】
実施例６
合成例１で得られた酢酸ビニル系重合体（重合度：１６８０，変性度：５．０モル％）の５０質量％メタノール溶液１００質量部に水酸化ナトリウムの４％メタノール溶液を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥し、ケン化度９８．５モル％のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物を得た。
【００４３】
メタノール２００質量部に上記のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物５０質量部を加えて浸漬させた。更に、γ−アミノプロピルトリメトキシシラン８．８質量部（酢酸ビニル系重合体に対して５．０モル％）を添加し、６０℃の乾燥機内でメタノールを蒸発させ、ビニルアルコール系重合体を得た。
【００４４】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００４５】
実施例７
合成例１で得られた酢酸ビニル系重合体（重合度：１６８０，変性度：５．０モル％）の５０質量％メタノール溶液１００質量部に水酸化ナトリウムの４％メタノール溶液を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥し、ケン化度８８．０モル％のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物を得た。
【００４６】
メタノール２００質量部に上記のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物５０質量部を加えて浸漬させた。更に、γ−アミノプロピルトリエトキシシラン４．０質量部（酢酸ビニル系重合体に対して２．０モル％）を添加し、６０℃の乾燥機内でメタノールを蒸発させ、ビニルアルコール系重合体を得た。
【００４７】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００４８】
実施例８
合成例２で得られた酢酸ビニル系重合体（重合度：１４９０，変性度：１０．５モル％）の５０質量％メタノール溶液１００質量部に水酸化ナトリウムの４％メタノール溶液を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥し、ケン化度９５．５モル％のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物を得た。
【００４９】
メタノール２００質量部に上記のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物５０質量部に加えて浸漬させた。更に、γ−アミノプロピルトリメトキシシラン０．８質量部（酢酸ビニル系重合体に対して０．５モル％）を添加し、６０℃の乾燥機内でメタノールを蒸発させ、ビニルアルコール系重合体を得た。
【００５０】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００５１】
実施例９
合成例２で得られた酢酸ビニル系重合体（重合度：１４９０，１０．５モル％）の５０質量％メタノール溶液１００質量部に水酸化ナトリウムの４％メタノール溶液を加えてよく混合し、４０℃でケン化反応を行った。得られたゲル状物を粉砕し、メタノールでよく洗浄した後に乾燥し、ケン化度９８．５モル％のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物を得た。
【００５２】
メタノール２００質量部に上記のジアセトンアクリルアミド−酢酸ビニル共重合体のケン化物５０質量部を加えて浸漬させた。更に、γ−アミノプロピルトリエトキシシラン１６．３質量部（酢酸ビニル系重合に対して８．５モル％）を添加し、６０℃の乾燥機内でメタノールを蒸発させ、ビニルアルコール系重合体を得た。
【００５３】
得られたビニルアルコール系重合体の水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は高く、シリカ化合物に対して高い結着性を示した。
【００５４】
比較例１
γ−アミノプロピルトリメトキシシランを使用しない以外は実施例１と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００５５】
比較例２
γ−アミノプロピルトリメトキシシランを使用しない以外は実施例６と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００５６】
比較例３
γ−アミノプロピルトリメトキシシランの添加量を５．０質量部から０．０５質量部（酢酸ビニル系重合体に対して０．０５モル％）に変更した以外は実施例１と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、実施例に比較して、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００５７】
比較例４
合成例１で得られた酢酸ビニル系重合体に代えて比較合成例１で得られた酢酸ビニル系重合体（重合度：１７１０，変性度：０．０５モル％）を使用した以外は実施例１と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、実施例に比較して、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００５８】
比較例５
合成例１で得られた酢酸ビニル系重合体に代えて比較合成例２で得られた未変性ポリ酢酸ビニル（重合度：１６９０，変性度：０モル％）を使用した以外は実施例１と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００５９】
比較例６
γ−アミノプロピルトリメトキシシランに代えてγ−グリシドキシプロピルトリメトキシシラン（アミノ基を有しないシランカップリング剤）を使用した以外は実施例１と同様にしてビニルアルコール系重合体を作製し、その水溶液を用いて、シリカ蒸着フィルムへの密着性、粒子状シリカに対するバインダー力を評価した。表２に示すように、密着性、バインダー力は低く、シリカ化合物に対する結着性は実用レベルに達しなかった。
【００６０】
【表２】

【００６１】
【発明の効果】
本発明によれば、シリカ化合物との結着性が優れたシラノール基含有ビニルアルコール系重合体を工業的に有利な方法で得ることが可能であり、しかも得られたシラノール基含有重合体は、シリカ化合物との結着性を高めることによって性能を改良することが可能なシリカ蒸着層を有する熱可塑性フィルムの塗工剤、インクジェットプリンター用基材のバインダーなどの実用的に有用な用途に有効に適用することが可能である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vinyl alcohol polymer having a high binding property with a silica compound and a method for producing the same.
[0002]
[Prior art]
Polyvinyl alcohol (hereinafter abbreviated as PVA) resins have high film-forming properties and are excellent in adhesion and gas barrier properties, and are therefore used in a wide range of applications such as films, coating films, and binders. For example, a laminated film obtained by forming a coating film of a PVA-based resin on a thermoplastic film having a silica vapor-deposited layer has advantages such as high gas barrier properties and no generation of toxic gases when discarded by incineration. In recent years, interest in the environment has increased and has attracted attention. However, the adhesion between the silica vapor deposition layer and the PVA coating film is not high, and there is a problem that the silica vapor deposition layer and the PVA coating film are peeled off when used under high humidity. In addition, particulate silica is used as an ink absorbent for a substrate for an ink jet printer, and a PVA resin is used as a binder, but there is a problem that the surface strength of the obtained substrate is not sufficient. . The problem of any use is due to insufficient binding force between the PVA resin and the silica compound, and is considered to be a problem that can be solved by introducing a silanol group into PVA.
[0003]
For such PVA resins having a silanol group introduced, a vinyl monomer having an alkoxysilyl group and vinyl acetate are copolymerized in JP-A-58-59203 and JP-A-58-164604. However, a silanol group-containing PVA resin obtained by this method has a high binding property with a silica compound, and the use of the silica compound and the PVA resin improves performance. The effect is seen.
[0004]
However, when copolymerizing a monomer having an alkoxysilyl group and a fatty acid vinyl ester such as vinyl acetate, a large amount of an unreacted monomer having an alkoxysilyl group remains after the polymerization, which is difficult to remove. There is a problem that an additional facility must be newly installed in the production facility. Moreover, the monomer which has an alkoxy silyl group was expensive, and there existed a problem that the cost of the silanol group containing PVA-type resin obtained was high. Therefore, a silanol group-containing PVA resin obtained by an industrially advantageous method has been demanded.
[0005]
[Problems to be solved by the invention]
The present invention improves the drawbacks of the prior art, and is obtained by an industrially advantageous method, and has excellent binding properties with a silica compound. For example, a vinyl alcohol polymer useful for applications such as a coating agent for a thermoplastic film having a silica vapor-deposited layer and a binder for a substrate for an ink jet printer, and a method for producing the same It is what.
[0006]
[Means for Solving the Problems]
This invention achieves the said objective, Comprising: In the copolymer which has a vinyl alcohol structural unit as a main component, 0.1-15 mol% of structural units represented by following Chemical formula 2 are contained. And a method for producing the same.
[0007]
[Chemical formula 2]

(X = 0-3, y = 0-1, z = 1-5 integer, R ₁ . R ₂ Is a hydrogen atom, a methyl group or an ethyl group, R ₃ Represents a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a methoxy group or an ethoxy group. )
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0009]
The vinyl alcohol polymer of the present invention is mainly composed of a vinyl alcohol structural unit and contains 0.1 to 15 mol% of a structural unit represented by the following chemical formula 3; Saponified vinyl ester units, diacetone acrylamide units and the like can be included.
[0010]
[Chemical 3]

(X = 0-3, y = 0-1, z = 1-5 integer, R ₁ . R ₂ Is a hydrogen atom, a methyl group or an ethyl group, R ₃ Represents a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a methoxy group or an ethoxy group. )
[0011]
The vinyl alcohol polymer of the present invention is prepared by first preparing a diacetone acrylamide-fatty acid vinyl ester copolymer, and reacting the silane coupling agent having an amino group with the copolymer in the presence of a methanol solvent. And then saponifying the diacetone acrylamide-fatty acid vinyl ester copolymer and then reacting with a silane coupling agent having an amino group in the presence of a methanol solvent. In any of the production methods, the vinyl alcohol polymer of the present invention can be obtained by reacting the amino group of the silane coupling agent with the diacetone acrylamide unit.
[0012]
Examples of the fatty acid vinyl ester used in the production of the diacetone acrylamide-fatty acid vinyl ester copolymer include vinyl formate, vinyl acetate, vinyl propionate, vinyl versatate and the like. Among them, vinyl acetate is industrially most preferable. .
[0013]
As a copolymerization method of diacetone acrylamide and a fatty acid vinyl ester, various polymerization methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization and the like that are conventionally known in the production method of vinyl ester polymers can be used. Among them, solution polymerization using methanol as a solvent is industrially preferable.
[0014]
The diacetone acrylamide-fatty acid vinyl ester copolymer used in the present invention is copolymerizable with diacetone acrylamide or a fatty acid vinyl ester, for example, within a range not inhibiting the effects of the present invention, such as crotonic acid, acrylic acid, methacrylic acid. Unsaturated monocarboxylic acids and their esters / salts / anhydrides / amides / nitriles, unsaturated dicarboxylic acids such as maleic acid, itaconic acid, fumaric acid and their salts, monomethyl maleate, monomethyl itaconate, etc. Dibasic acid monoalkyl esters, α-olefins having 2 to 30 carbon atoms, alkyl vinyl ethers, vinyl pyrrolidones, 3- (meth) acrylamidopropyltrimethoxysilane, 3- (meth) acrylamidopropyltriethoxysilane, 3 -(Meth) acrylamide Pro Lutri (β-methoxyethoxy) silane, 3- (meth) acrylamidopropyl (N-methylaminoethoxysilane), 2- (meth) acrylamidoethyltrimethoxysilane, 1- (meth) acrylamidomethyltrimethoxysilane, 2- ( It may be copolymerized with a monomer having an alkoxysilyl group such as (meth) acrylamido-2-methylpropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane. .
[0015]
Content of the diacetone acrylamide unit in a diacetone acrylamide-fatty acid vinyl ester copolymer is 0.1-15 mol%, Preferably it is 1-10 mol%. When the diacetone acrylamide unit is less than 0.1 mol%, the amount of silane coupling agent having an amino group to be added is reduced, and the final binding property of the vinyl alcohol polymer to the silica compound is low. On the other hand, even if it exceeds 15 mol%, the binding property to the silica compound does not change, which is disadvantageous in that the production cost is increased.
[0016]
As a method of reacting a diacetone acrylamide-fatty acid vinyl ester copolymer with an amino group-containing silane coupling agent before saponification, an amino group-containing silane coupling agent is added to the methanol solution of the copolymer. And stirring and mixing at room temperature or high temperature.
[0017]
Examples of the silane coupling agent having an amino group used here include, for example, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N -Β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, etc., and one or two of these A combination of the above can also be used.
[0018]
Further, the addition amount of the silane coupling agent having an amino group is an amount corresponding to 0.1 to 15 mol%, preferably 1 to 10 mol%, relative to the diacetone acrylamide-fatty acid vinyl ester copolymer. Is equivalent to When the addition amount of the silane coupling agent having an amino group is small and less than 0.1 mol% with respect to the copolymer, the binding property of the finally obtained vinyl alcohol polymer to the silica compound is low, On the other hand, even if it exceeds 15 mol%, the binding property to the silica compound does not change, which is disadvantageous in that the production cost increases. Moreover, even if the addition amount of the silane coupling agent having an amino group exceeds the content of the diacetone acrylamide unit in the copolymer, the binding property to the silica compound is not improved and the production cost is increased. This is disadvantageous.
[0019]
In addition, a saponification method of a polymer obtained by reacting a diacetone acrylamide-fatty acid vinyl ester copolymer with a silane coupling agent having an amino group includes a conventionally known alkali saponification and acid saponification of a fatty acid vinyl ester copolymer. In particular, a method in which an alkali hydroxide is added to a methanol solution of a polymer or a mixed solution of methanol and water, methyl acetate, benzene or the like to perform alcoholysis is industrially preferable.
[0020]
On the other hand, as a method of reacting a saponified diacetone acrylamide-fatty acid vinyl ester copolymer with a silane coupling agent having an amino group, a silane coupling having an amino group to the diacetone acrylamide-fatty acid vinyl ester copolymer After saponification and pulverization by the above saponification method of the fatty acid vinyl ester polymer without adding an agent, add the silane coupling agent having an amino group and stir at room temperature or high temperature. The method of doing is mentioned.
[0021]
In that case, the said silane coupling agent which has an amino group can be used, and also the addition amount is 0.1-15 mol% with respect to the saponification product of a diacetone acrylamide-fatty acid vinyl ester copolymer similarly to the above. Is equivalent to
[0022]
The polymerization degree and saponification degree of the vinyl alcohol polymer reacted with a silane coupling agent having an amino group before and after saponification are not particularly limited, but the saponification degree is 80 mol% or more, and the polymerization degree is 50-4000 are preferable.
[0023]
Even in the case of reacting a silane coupling agent having an amino group before and after saponification, methanol must be present in the reaction system, and in a solvent other than methanol, the reaction is extremely slow, and the intended vinyl alcohol system A polymer cannot be obtained easily. In the reaction, a solvent such as water, ethanol, ether, benzene or the like other than methanol may coexist, but the higher the methanol ratio in the solvent, the higher the speed during the reaction, which is preferable.
[0024]
The vinyl alcohol polymer of the present invention is water-soluble and is prepared as an aqueous solution when used. The preparation method is not particularly limited, but when the aqueous solution of the vinyl alcohol polymer of the present invention is prepared, cellulose derivatives such as starch, methyl cellulose, carboxymethyl cellulose, polyacrylic acid derivatives, gelatin, etc. Other natural polymers, synthetic polymers, clay, kaolin, talc, silica, inorganic fillers such as calcium carbonate, plasticizers such as glycerin and sorbitol, surfactants, antifoaming agents, antistatic agents, chelating agents, crosslinks An agent etc. can be mix | blended in the range which does not impair the effect of this invention.
[0025]
【Example】
Next, the present invention will be described specifically by way of examples.
Evaluation of the vinyl alcohol polymer obtained in the examples or comparative examples was performed by the following method.
[0026]
(1). Evaluation of adhesion to silica-deposited film
A 5% by mass aqueous solution of the resulting vinyl alcohol polymer was prepared and cast on a vapor deposition surface of a polyethylene terephthalate film (thickness 12 μm) subjected to silica vapor deposition treatment, and subjected to conditions of 20 ° C. and 65% RH for 24 hours. It dried and formed the coating film about 50 micrometers thick.
The silica vapor-deposited film having the vinyl alcohol polymer coating film was cut into a size of 100 mm × 20 mm, and the peel strength between the 20 mm-wide coating film and the silica vapor-deposited film was measured with a Toyo Seiki strograph. .
[0027]
(2). Evaluation of binder force on particulate silica
A 5% by mass aqueous solution of the obtained vinyl alcohol polymer was prepared, 20 parts by mass of particulate silica and 50 parts by mass of pure water were added to 100 parts by mass of this aqueous solution, and a homomixer (stirring speed: 10,000 rpm) was used. The mixture was stirred at room temperature for 5 minutes to prepare a coating solution.
Apply the above coating solution on a copy sheet (Ricoh, My Recycle Paper New). About 10 g / m using 40 bar coaters ² (Solid content) was applied, and drying was performed at 105 ° C. for 120 seconds using a drum dryer.
Nichiban cellophane adhesive tape (width: 18 mm) was affixed to the resulting coated paper, the peel strength was measured with a Toyo Seiki strograph, and the binder strength of the coated layer was evaluated.
[0028]
(3). Comprehensive evaluation
By combining the evaluation results of the adhesion to the silica deposited film and the binder force to the particulate silica, the binding property to the silica compound was evaluated according to the following criteria.
(Double-circle): The binding property with respect to a silica compound is very excellent.
A: Excellent binding property to the silica compound and at a practical level.
X: The binding property to the silica compound does not reach a practical level.
[0029]
Synthesis example of diacetone acrylamide-vinyl acetate copolymer
Synthesis example 1
A flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 672 parts by mass of vinyl acetate, 10 parts by mass of diacetone acrylamide, and 178 parts by mass of methanol, and after replacing the nitrogen in the system, The temperature was raised to 60 ° C. To this system, a solution prepared by dissolving 1 part by mass of 2,2'-azobisisobutyronitrile in 50 parts by mass of methanol was added to initiate polymerization. Over 5 hours after the start of polymerization, a solution prepared by dissolving 55 parts by mass of diacetone acrylamide in 35 parts by mass of methanol was added dropwise at a constant rate, and after 6 hours, the polymerization was stopped. The polymerization yield was 78%. The remaining vinyl acetate was distilled while adding methanol vapor to the resulting reaction mixture to obtain a 50% by mass methanol solution of a vinyl acetate polymer containing a diacetone acrylamide copolymer component. As shown in Table 1, the content of diacetone acrylamide units in this resin was 5.0 mol% by elemental analysis measurement, and the degree of polymerization was 1680.
[0030]
Synthesis Examples 2-3 and Comparative Synthesis Examples 1-2
According to the above method, vinyl acetate and diacetone acrylamide are copolymerized, and three types of vinyl acetate polymers having different diacetone acrylamide units and different degrees of polymerization and unmodified polyvinyl acetate not using diacetone acrylamide One kind was obtained. Table 1 shows data on the degree of modification and the degree of polymerization of these resins.
[0031]
[Table 1]

[0032]
Example 1
To 100 parts by mass of a 50% methanol solution of the vinyl acetate polymer obtained in Synthesis Example 1 (polymerization degree: 1680, modification degree: 5.0 mol%), 5.0 parts by mass of γ-aminopropyltrimethoxysilane (acetic acid 5.0 mol% with respect to the vinyl polymer), and after mixing and stirring at room temperature, 1 mass part of a 4 mass% methanol solution of sodium hydroxide was added and mixed well, and the saponification reaction was carried out at 40 ° C. went. The obtained gel-like material was pulverized, thoroughly washed with methanol, and then dried to obtain a vinyl alcohol polymer having a saponification degree of 98.5 mol%.
[0033]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica vapor deposited film and the hindering force against the particulate silica were evaluated. As shown in Table 2, the adhesion and hindering force were high, and high binding property to the silica compound was exhibited.
[0034]
Example 2
N-β (aminoethyl) γ-aminopropyltrimethoxy was added to 100 parts by mass of a 50% by mass methanol solution of the vinyl acetate polymer obtained in Synthesis Example 1 (polymerization degree: 1680, modification degree: 5.0 mol%). After adding 3.7 parts by mass of silane (3.0 mol% with respect to the vinyl acetate polymer) and mixing and stirring at room temperature, 1 part by mass of a 4% methanol solution of sodium hydroxide was added and mixed well. The saponification reaction was performed at 40 ° C. The obtained gel-like material was pulverized, thoroughly washed with methanol, and then dried to obtain a vinyl alcohol polymer having a saponification degree of 98.4 mol%.
[0035]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0036]
Example 3
N-β (aminoethyl) γ-aminopropylmethyldimethoxy was added to 100 parts by mass of a 50% by mass methanol solution of the vinyl acetate polymer obtained in Synthesis Example 2 (degree of polymerization: 1490, degree of modification: 10.5 mol%). After adding 10.9 parts by mass of silane (10.0 mol% with respect to the vinyl acetate polymer) and mixing and stirring at room temperature, 1.5 parts by mass of a 4% by mass methanol solution of sodium hydroxide may be added. The saponification reaction was carried out at 40 ° C. The obtained gel-like material was pulverized, thoroughly washed with methanol, and then dried to obtain a vinyl alcohol polymer having a saponification degree of 98.4 mol%.
[0037]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesion and hindering force were high, and high binding property to the silica compound was exhibited.
[0038]
Example 4
N-β (aminoethyl) γ-aminopropyltriethoxy was added to 100 parts by mass of a 50% by mass methanol solution of the vinyl acetate polymer (polymerization degree: 1490, modification degree: 10.5 mol%) obtained in Synthesis Example 2. After adding 5.6 parts by mass of silane (4.0 mol% with respect to the vinyl acetate polymer) and mixing and stirring at room temperature, 1.0 part by mass of a 4% by mass methanol solution of sodium hydroxide may be added. The saponification reaction was carried out at 40 ° C. The obtained gel-like material was pulverized, washed thoroughly with methanol and then dried to obtain a vinyl alcohol polymer having a saponification degree of 88.4 mol%.
[0039]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesiveness to the silica vapor deposition film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0040]
Example 5
To 100 parts by mass of a 50% by mass methanol solution of the vinyl acetate polymer obtained in Synthesis Example 3 (degree of polymerization: 650, degree of modification: 1.2 mol%), 1.0 part by mass of γ-aminopropyltrimethoxysilane ( 1.0 mol% with respect to the vinyl acetate polymer), and mixed and stirred at room temperature. Then, 1.0 part by mass of a 4% by mass methanol solution of sodium hydroxide was added and mixed well. The reaction was carried out. The obtained gel-like material was pulverized, thoroughly washed with methanol, and then dried to obtain a vinyl alcohol polymer having a saponification degree of 98.5 mol%.
[0041]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesiveness to the silica vapor deposition film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0042]
Example 6
A 4% methanol solution of sodium hydroxide was added to 100 parts by mass of a 50% methanol solution of the vinyl acetate polymer obtained in Synthesis Example 1 (polymerization degree: 1680, modification degree: 5.0 mol%) and mixed well. The saponification reaction was performed at 40 ° C. The obtained gel-like material was pulverized, washed thoroughly with methanol and dried to obtain a saponified product of diacetone acrylamide-vinyl acetate copolymer having a saponification degree of 98.5 mol%.
[0043]
50 parts by mass of the above saponified diacetone acrylamide-vinyl acetate copolymer was added to 200 parts by mass of methanol and immersed. Further, 8.8 parts by mass of γ-aminopropyltrimethoxysilane (5.0 mol% with respect to the vinyl acetate polymer) was added, methanol was evaporated in a dryer at 60 ° C., and a vinyl alcohol polymer was obtained. Obtained.
[0044]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0045]
Example 7
A 4% methanol solution of sodium hydroxide was added to 100 parts by mass of a 50% methanol solution of the vinyl acetate polymer obtained in Synthesis Example 1 (polymerization degree: 1680, modification degree: 5.0 mol%) and mixed well. The saponification reaction was performed at 40 ° C. The obtained gel was pulverized, washed thoroughly with methanol and dried to obtain a saponified product of diacetone acrylamide-vinyl acetate copolymer having a saponification degree of 88.0 mol%.
[0046]
50 parts by mass of the above saponified diacetone acrylamide-vinyl acetate copolymer was added to 200 parts by mass of methanol and immersed. Further, 4.0 parts by mass of γ-aminopropyltriethoxysilane (2.0 mol% with respect to the vinyl acetate polymer) was added, methanol was evaporated in a dryer at 60 ° C., and a vinyl alcohol polymer was obtained. Obtained.
[0047]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0048]
Example 8
Add 4% methanol solution of sodium hydroxide to 100 parts by mass of 50% methanol solution of the vinyl acetate polymer obtained in Synthesis Example 2 (degree of polymerization: 1490, degree of modification: 10.5 mol%) and mix well. The saponification reaction was performed at 40 ° C. The obtained gel-like material was pulverized, washed thoroughly with methanol and then dried to obtain a saponified product of diacetone acrylamide-vinyl acetate copolymer having a saponification degree of 95.5 mol%.
[0049]
In addition to 50 mass parts of the saponified diacetone acrylamide-vinyl acetate copolymer, 200 mass parts of methanol was immersed. Furthermore, 0.8 part by mass of γ-aminopropyltrimethoxysilane (0.5 mol% with respect to the vinyl acetate polymer) was added, methanol was evaporated in a dryer at 60 ° C., and a vinyl alcohol polymer was obtained. Obtained.
[0050]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0051]
Example 9
A 4% methanol solution of sodium hydroxide was added to 100 parts by mass of a 50% by mass methanol solution of the vinyl acetate polymer (polymerization degree: 1490, 10.5 mol%) obtained in Synthesis Example 2, and mixed well. The saponification reaction was performed at ° C. The obtained gel-like material was pulverized, washed thoroughly with methanol and dried to obtain a saponified product of diacetone acrylamide-vinyl acetate copolymer having a saponification degree of 98.5 mol%.
[0052]
50 parts by mass of the above saponified diacetone acrylamide-vinyl acetate copolymer was added to 200 parts by mass of methanol and immersed. Further, 16.3 parts by mass of γ-aminopropyltriethoxysilane (8.5 mol% with respect to vinyl acetate polymerization) was added, and methanol was evaporated in a dryer at 60 ° C. to obtain a vinyl alcohol polymer. It was.
[0053]
Using the obtained aqueous solution of the vinyl alcohol polymer, the adhesion to the silica deposited film and the binder force against the particulate silica were evaluated. As shown in Table 2, the adhesiveness and binder strength were high, and high binding property to the silica compound was exhibited.
[0054]
Comparative Example 1
A vinyl alcohol polymer was prepared in the same manner as in Example 1 except that γ-aminopropyltrimethoxysilane was not used, and the aqueous solution was used to evaluate the adhesion to a silica vapor deposited film and the binder strength against particulate silica. did. As shown in Table 2, the adhesion and binder strength were low, and the binding property to the silica compound did not reach a practical level.
[0055]
Comparative Example 2
A vinyl alcohol polymer was prepared in the same manner as in Example 6 except that γ-aminopropyltrimethoxysilane was not used, and the aqueous solution was used to evaluate the adhesion to the silica deposited film and the binder strength against particulate silica. did. As shown in Table 2, the adhesion and binder strength were low, and the binding property to the silica compound did not reach a practical level.
[0056]
Comparative Example 3
Vinyl was added in the same manner as in Example 1 except that the amount of γ-aminopropyltrimethoxysilane added was changed from 5.0 parts by mass to 0.05 parts by mass (0.05 mol% with respect to the vinyl acetate polymer). An alcohol-based polymer was prepared, and the aqueous solution was used to evaluate the adhesion to a silica vapor deposited film and the binder strength against particulate silica. As shown in Table 2, compared to the examples, the adhesion and binder strength were low, and the binding property to the silica compound did not reach the practical level.
[0057]
Comparative Example 4
Example except that the vinyl acetate polymer obtained in Comparative Synthesis Example 1 (polymerization degree: 1710, modification degree: 0.05 mol%) was used instead of the vinyl acetate polymer obtained in Synthesis Example 1. A vinyl alcohol polymer was prepared in the same manner as in No. 1, and the aqueous solution was used to evaluate the adhesion to a silica vapor deposited film and the binder strength against particulate silica. As shown in Table 2, compared to the examples, the adhesion and binder strength were low, and the binding property to the silica compound did not reach the practical level.
[0058]
Comparative Example 5
Example 1 except that the unmodified polyvinyl acetate (polymerization degree: 1690, modification degree: 0 mol%) obtained in Comparative Synthesis Example 2 was used in place of the vinyl acetate polymer obtained in Synthesis Example 1. Similarly, a vinyl alcohol polymer was prepared, and the aqueous solution was used to evaluate the adhesion to a silica vapor deposited film and the binder strength against particulate silica. As shown in Table 2, the adhesion and binder strength were low, and the binding property to the silica compound did not reach a practical level.
[0059]
Comparative Example 6
A vinyl alcohol polymer was prepared in the same manner as in Example 1 except that γ-glycidoxypropyltrimethoxysilane (a silane coupling agent having no amino group) was used instead of γ-aminopropyltrimethoxysilane. The aqueous solution was used to evaluate the adhesion to the silica vapor deposited film and the binder force against the particulate silica. As shown in Table 2, the adhesion and binder strength were low, and the binding property to the silica compound did not reach a practical level.
[0060]
[Table 2]

[0061]
【The invention's effect】
According to the present invention, it is possible to obtain a silanol group-containing vinyl alcohol polymer having excellent binding properties with a silica compound by an industrially advantageous method, and the obtained silanol group-containing polymer is: Effective for practically useful applications such as coating agents for thermoplastic films with silica vapor deposition layers and binders for inkjet printer substrates, which can improve performance by enhancing the binding properties with silica compounds It is possible to apply.

Claims (3)

In the copolymer consisting mainly of vinyl alcohol structural units, the structural unit represented by the formula 1 below contains 0.1 to 15 mol%, vinyl alcohol, wherein the degree of polymerization 50 to 4000 der Rukoto Polymer.

(X = 0~3, y = 0~1 , z = 1~5 _integer, R 1, _{R 2} is a hydrogen atom, a methyl group or an ethyl group, _{R 3} is a hydrogen atom, ethyl group, methoxy Group or ethoxy group.) Diacetone in a fatty acid vinyl ester copolymer having a diacetone acrylamide unit by reacting a fatty acid vinyl ester copolymer having a diacetone acrylamide unit with a silane coupling agent having an amino group in a methanol solvent. The content of acrylamide units is 0.1 to 15 mol%, and the amount of the silane coupling agent is 0.1 to 15 mol% with respect to the fatty acid vinyl ester copolymer having the diacetone acrylamide units. The method for producing a vinyl alcohol polymer according to claim 1 . In methanol solvent, a saponification product of diacetone acrylamide-fatty acid vinyl ester copolymer is reacted with a silane coupling agent having an amino group, and the diacetone acrylamide unit in the fatty acid vinyl ester copolymer having the diacetone acrylamide unit is reacted . content is 0.1 to 15 mol%, in the methanol solvent, diacetone acrylamide - and wherein 0.1 to 15 mol% der Rukoto respect fatty acid vinyl ester copolymer saponified The method for producing a vinyl alcohol polymer according to claim 1 .