JP3909990B2 - Organic polymer / inorganic fine particle dispersed aqueous solution excellent in dispersion stability and use thereof - Google Patents

Description

【００２９】
エチレン性の親水性不飽和化合物のイオン性化合物のなかで、アニオン性を示す化合物の例としては、不飽和カルボン酸化合物、不飽和スルホン酸化合物、その他のアニオン性不飽和化合物等からなる群より選択された一種以上の化合物である。本発明では、その中で不飽和カルボン酸化合物は必須成分であるが、不飽和カルボン酸化合物だけでなく、不飽和カルボン酸アミド化合物や不飽和カルボン酸エステル化合物などのように、加水分解等の後反応によりカルボキシル基を生成することが可能なものを共重合成分として含有するものでもよく、後反応によりカルボキシル基を生成させても良い。不飽和カルボン酸化合物は不飽和化合物総量に対して概ね０．１〜８０モル％または０．１〜８０重量％、好ましくは０．５〜５０モル％または０．５〜５０重量％共重合される。
【００３０】
不飽和カルボン酸化合物としては、アクリル酸、メタクリル酸、クロトン酸、アンゲリカ酸、チグリン酸、２−ペンテン酸、β−メチルクロトン酸、β−メチルチグリン酸、α−メチル−２−ペンテン酸、β−メチル−２−ペンテン酸、マレイン酸、フマル酸、無水マレイン酸、イタコン酸、シトラコン酸、メサコン酸、グルタコン酸、α−ジヒドロムコン酸、２，３−ジメチルマレイン酸、２−メチルグルタコン酸、３−メチルグルタコン酸、２−メチル−α−ジヒドロムコン酸、２，３−ジメチル−α−ジヒドロムコン酸等の酸およびそれらのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
【００３１】
不飽和スルホン酸化合物としては、ビニルスルホン酸、スチレンスルホン酸、２−アクリルアミド−２−フェニルプロパンスルホン酸、２−アクリルアミド−２−メチルプロパンスルホン酸、アリルスルホン酸、メタリルスルホン酸等のスルホン酸およびそれらのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
その他のアニオン性不飽和化合物としては、リン酸モノ（２−ヒドロキシエチル）メタクリルエステル等のリン酸およびそのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
【００３２】
エチレン性の親水性不飽和化合物のイオン性化合物のなかで、カチオン性を示す化合物の例としては、Ｎ，Ｎ−ジメチルアミノエチルアクリレート（ＤＡ）、Ｎ，Ｎ−ジメチルアミノエチルメタクリレート（ＤＭ）、Ｎ，Ｎ−ジエチルアミノエチルアクリレート、Ｎ，Ｎ−ジエチルアミノエチルメタクリレート、Ｎ，Ｎ−ジメチルアミノプロピルアクリルアミド（ＤＭＡＰＡＡ）、Ｎ，Ｎ−ジメチルアミノプロピルメタクリルアミド（ＤＭＡＰＭＡ）等の塩基性ビニル化合物とそれらの塩および、アリルアミン、Ｎ−メチルアリルアミン、２−メチルアリルアミン、ジアリルアミン等のアリルアミン類とそれらの塩等がある。さらには、ＤＡ、ＤＭ、ＤＭＡＰＡＡ、ＤＭＡＰＭＡ等をジメチル硫酸、メチルクロライドやメチルブロマイド等のハロゲン化アルキル類、アリルクロライド、ベンジルクロライドやベンジルブロマイド等のハロゲン化ベンジル類、エピクロロヒドリンやエピブロモヒドリン等のエピハロヒドリン類、プロピレンオキシドやスチレンオキシド等のエポキシ類で四級化したビニル化合物や、ジメチルジアリルアンモニウムクロリドなどをあげることができる。
【００３３】
上記エチレン性の親水性不飽和化合物には、水溶性あるいは水分散性を損なわない程度にエチレン性の疎水性不飽和化合物を共重合することが可能である。疎水性不飽和化合物の共重合比率は、モノマーの種類や共重合の組み合わせ等により変わるので特定できないが、比率が高くなると水溶性を失うため、疎水性不飽和化合物の量は概ね９９〜０重量％の範囲であって、しかも共重合体の水溶性を失わない程度に抑える必要がある。
【００３４】
エチレン性の疎水性不飽和化合物の例としては、芳香族ビニル化合物、シアン化ビニル化合物、ジエン化合物、不飽和カルボン酸エステル化合物、ビニルアルキルエーテル化合物、その他のビニル化合物、および疎水性アリル化合物からなる群より選択された一種以上の化合物である。
【００３５】
芳香族ビニル化合物は、スチレン、α−メチルスチレン、α−クロロスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−メチルスチレン、ｐ−クロロスチレン、ｏ−クロロスチレン、２，５−ジクロロスチレン、３，４−ジクロロスチレン、ジメチルスチレン、ジビニルベンゼン等をあげることができる。
シアン化ビニル化合物は、アクリロニトリル、メタクリロニトリル、α−クロロアクリロニトリル等をあげることができる。
ジエン化合物は、アレン、ブタジエン、イソプレン等のジオレフィン化合物および、クロロプレン等をあげることができる。
【００３６】
不飽和カルボン酸エステル化合物は、メチルアクリレート、メチルメタクリレート、エチルアクリレート、エチルメタクリレート、プロピルアクリレート、プロピルメタクリレート、ブチルアクリレート、ブチルメタクリレート、２−エチルヘキシルアクリレート、２−エチルヘキシルメタクリレート、ラウリルアクリレート、ラウリルメタクリレート、ベンジルアクリレート、ベンジルメタクリレート、シクロヘキシルアクリレート、シクロヘキシルメタクリレート、グリシジルアクリレート、グリシジルメタクリレート、エチレングリコールジアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジアクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジアクリレート、トリエチレングリコールジメタクリレート、１，４−ブタンジオールジアクリレート、１，６−ヘキサンジオールアクリレート、テトラエチレングリコールジメタクリレート、１，３−ブチレングリコールジメタクリレート、ポリエチレングリコール（メタ）アクリレート、メトキシポリエチレングリコール（メタ）アクリレート、エトキシポリエチレングリコール（メタ）アクリレート、プロポキシポリエチレングリコール（メタ）アクリレート、イソプロポキシポリエチレングリコール（メタ）アクリレート、フェノキシポリエチレングリコール（メタ）アクリレート、およびエポキシアクリレート類やウレタンアクリレート類のジビニル化合物等をあげることができる。
【００３７】
ビニルアルキルエーテル化合物は、ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソプロピルエーテル、ビニルｎ−プロピルエーテル、ビニルイソブチルエーテル、ビニル２−エチルヘキシルエーテル、ビニルｎ−オクタデシルエーテル等をあげることができる。
その他のビニル化合物としては、酢酸ビニル、プロピオン酸ビニル等のビニルエステル類、エチレン、プロピレン、ブテン、α−オレフィン等のオレフィン類、ブタジエン、イソプレン、クロロプレン等のジエン化合物、塩化ビニル、塩化ビニリデン、フッ化ビニル、フッ化ビニリデン等のハロゲン化オレフィン類、アジピン酸ジビニル、セバシン酸ジビニル等のジビニルエステル類、ジエチルフマレート、ジメチルイタコネート等のカルボン酸ジアルキルエステル類、マレイミド、Ｎ−フェニルマレイミド、Ｎ−シクロヘキシルマレイミド等をあげることができる。
【００３８】
さらに、疎水性のアリル化合物としては、ジアリルイソフタレート、ジアリルテレフタレート、ジエチレングリコールジアリルカーボネート、トリアリルシアヌレート等をあげることができる。
【００３９】
本発明に用いられる親水性モノマーの重合体を製造する方法は、公知の重合方法、例えば水溶液重合、沈殿重合、乳化重合等を用いることが出来る。回分重合、半回分重合の何れの組み合わせでもよく、重合方法は何等制限されない。
【００４０】
ラジカル重合を行う場合、通常はラジカル重合開始剤の存在下、重合溶液を所定温度に保つことにより重合を行う。重合中同一温度に保つ必要はなく、重合の進行にともない適宜変えてよく、必要に応じて加熱あるいは除熱しながら行う。重合温度は、使用するモノマーの種類や重合開始剤の種類などにより異なり、単一開始剤の場合には概ね３０〜１００℃の範囲であり、レドックス系重合開始剤の場合にはより低く、一括で重合を行う場合には概ね−５〜５０℃であり、逐次添加する場合には概ね３０〜９０℃である。重合器内の雰囲気は特に限定はないが、重合を速やかに行わせるには窒素ガスのような不活性ガスで置換した方がよい。重合時間は特に限定はないが、概ね１〜４０時間である。
【００４１】
重合溶媒としては水を用いるが、メタノール、エタノール、イソプロパノール、アセトン、エチレングリコール、プロピレングリコール等の有機溶剤を併用してもよい。
重合濃度は、モノマー濃度で１〜４０重量％、好ましくは２〜３０重量％である。
【００４２】
ラジカル重合開始剤としては、一般の水溶性の開始剤が使用できる。過酸化物系では、例えば過硫酸アンモニウム、過硫酸カリウム、過酸化水素、ｔｅｒｔ−ブチルパーオキサイド等があげられる。この場合、単独でも使用できるが、還元剤と組み合わせてレドックス系重合剤としても使える。還元剤としては、例えば亜硫酸塩、亜硫酸水素塩、鉄、銅、コバルト等の低次のイオンの塩、次亜リン酸、次亜リン酸塩、Ｎ,Ｎ,Ｎ',Ｎ'-テトラメチルエチレンジアミン等の有機アミン、更にはアルドース、ケトース等の還元糖等をあげることができる。また、アゾ化合物系では、２,２'−アゾビス−２−アミジノプロパン塩酸塩、２,２'−アゾビス−２,４−ジメチルバレロニトリル、４,４'−アゾビス-４-シアノバレイン酸及びその塩等を使用することができる。更に上記した重合開始剤を２種以上併用してもよい。重合開始剤の添加量は、単量体に対して０．０００１〜１０重量％の範囲であり、好ましくは０．０１〜８重量％である。また、レドックス系の場合には、重合開始剤に対して還元剤の添加量はモル基準で０．１〜１００％、好ましくは０．２〜８０％である。
【００４３】
親水性モノマーの重合は、分子量あるいは重合速度を調整するなどの目的で、必要に応じてｐＨ調整剤、連鎖移動剤等を使用してもよい。
ｐＨ調整剤としては、水酸化ナトリウム、水酸化カリウム，アンモニア等の無機塩基類、エタノールアミン、トリメチルアミン、トリエチルアミン等の有機塩基類、及び炭酸水素ナトリウム、炭酸ナトリウム、酢酸ナトリウム、リン酸二水素ナトリウム等の塩類等があげられる。
【００４４】
連鎖移動剤としては、イソプロピルアルコール、α−チオグリセロール、メルカプトコハク酸、チオグリコール酸、トリエチルアミン、次亜リン酸ナトリウム等のなかから１種または２種以上の混合物を適宜使用することができる。
また、金属イオンを封止するあるいは重合速度を調整する等の目的で、エチレンジアミン４酢酸ナトリウム（ＥＤＴＡ−Ｎａ）や尿素、チオ尿素等の化合物を併用してもよい。ｐＨ調整剤、連鎖移動剤等の使用量は、使用目的に応じて異なるが、概ねモノマー重量に対してｐＨ調整剤は１００ppm〜１０％、連鎖移動剤やその他の添加剤は１．０ppm〜５．０％の範囲にある。
【００４５】
本発明で使用される（メタ）アクリルアミド系重合体やビニルピロリドン系重合体のような、親水性モノマーを重合して得た重合体の分子量は、ポリマー構造（直鎖／分岐など）により異なるが、概ね１．０×１０³〜５．０×１０⁶の範囲に及ぶ。これは、本発明の複合体が様々な用途で使用されるためであり、粒子の分散性が重視される用途では概ね１．０×１０³〜１．０×１０⁵、各種添加剤、フイルムなどの強度を要求される用途では１．０×１０⁴〜１．０×１０⁶、その他凝集剤や製紙用薬品などの用途では５．０×１０⁴〜５．０×１０⁶の範囲が好ましい。１．０×１０³以下の分子量ではポリマー自体の特性低下に加えて、無機微粒子への吸着力が低いため安定な分散溶液とならず、５．０×１０⁶以上の分子量では粒子間の架橋反応が優先するため、安定な分散溶液とならない。また、重合体に含まれるカルボキシル基量は、概ね０．１〜８０モル％または０．１〜８０重量％、好ましくは０．５〜５０モル％または０．５〜５０重量％の範囲にある。
【００４６】
次に、重合体を得た後で化学反応により親水基を生成する例には、ポリビニルアルコール（ＰＶＡ）やポリビニルアミンなどがあるが、カルボキシル基を分子内に持つ高分子化合物であれば、何れも使用できる。それらの中でもＰＶＡが最も好ましい。ＰＶＡとしては、分子内にカルボキシル基を有するポリビニルアルコール系重合体（カルボキシル基変性ポリビニルアルコール）が用いられ、通常はビニルエステル化合物とエチレン性不飽和カルボン酸との共重合体をケン化したもの、および／または末端にチオール基を有するポリビニルアルコール系重合体の存在下、エチレン性不飽和カルボン酸をラジカル共重合したものが使用される。
【００４７】
上記のビニルエステル化合物としては、酢酸ビニル、ギ酸ビニル、プロピオン酸ビニル、酪酸ビニル、イソ酪酸ビニル、ピバリン酸ビニル、カプリル酸ビニル等をあげることができるが、工業的には酢酸ビニルが好ましい。
【００４８】
上記エチレン性不飽和カルボン酸としては、アクリル酸、メタクリル酸、クロトン酸、アンゲリカ酸、チグリン酸、２−ペンテン酸、β−メチルクロトン酸、β−メチルチグリン酸、α−メチル−２−ペンテン酸、β−メチル−２−ペンテン酸等の不飽和モノカルボン酸、マレイン酸、フマル酸、無水マレイン酸、イタコン酸、無水イタコン酸、シトラコン酸、無水シトラコン酸、メサコン酸、グルタコン酸、α−ジヒドロムコン酸、２，３−ジメチルマレイン酸、２−メチルグルタコン酸、３−メチルグルタコン酸、２−メチル−α−ジヒドロムコン酸、２，３−ジメチル−α−ジヒドロムコン酸等の不飽和ジカルボン酸およびそれらのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
【００４９】
また、エチレン性不飽和カルボン酸の代りに、ケン化反応時にカルボキシル基を生成するエチレン性不飽和カルボン酸エステル、エチレン性不飽和ジカルボン酸モノエステル、エチレン性不飽和ジカルボン酸ジエステル、エチレン性不飽和カルボン酸アミドなどを共重合してもよい。また、エチレン性不飽和カルボン酸とこれらのケン化反応時にカルボキシル基を生成する化合物を一緒に共重合しても差し支えない。さらには、カルボキシル基変性ポリビニルアルコールの水溶性や安定性等に支障をきたさない程度に他の共重合可能なモノマーと共重合させることも可能である。
【００５０】
重合およびケン化方法は特に制限はなく、例えば特開昭５３−９１９９５号公報に開示されているような、公知の方法に従ってカルボキシル基変性ポリビニルアルコールを製造することができる。
【００５１】
末端にチオール基を有するポリビニルアルコール系重合体は、チオ酢酸のようなチオール基を含有する連鎖移動剤の存在下にビニルエステル化合物を重合し、その後ケン化反応を行うことにより得られる。重合の際には、カルボキシル基変性ポリビニルアルコールの水溶性や安定性等に支障をきたさない程度に共重合可能なモノマーと共重合させることも可能である。この末端にチオール基を有するポリビニルアルコール系重合体存在下にエチレン性不飽和カルボン酸をラジカル共重合すれば、カルボキシル基変性ポリビニルアルコール（ブロック共重合体）が製造される。これらのブロック重合の際にも、カルボキシル基変性ポリビニルアルコールの水溶性や安定性等に支障をきたさない程度に共重合可能なモノマーを共重合させることが可能である。その量は使用するモノマーの種類により異なるが、ケン化反応前のビニルエステル化合物に対して概ね１〜５０重量％の範囲にある。
【００５２】
共重合可能なモノマーには、エチレン性不飽和カルボン酸、エチレン性不飽和カルボン酸エステル、エチレン性不飽和ジカルボン酸モノエステル、エチレン性不飽和ジカルボン酸ジエステル、エチレン性不飽和カルボン酸アミド、アニオン性のエチレン性不飽和化合物、カチオン性のエチレン性不飽和化合物、非イオン性のエチレン性親水性不飽和化合物、エチレン性疎水性不飽和化合物がある。
【００５３】
エチレン性不飽和カルボン酸エステルは、メチルアクリレート、メチルメタクリレート、エチルアクリレート、エチルメタクリレート、プロピルアクリレート、プロピルメタクリレート、ブチルアクリレート、ブチルメタクリレート、２−エチルヘキシルアクリレート、２−エチルヘキシルメタクリレート、ラウリルアクリレート、ラウリルメタクリレート、ベンジルアクリレート、ベンジルメタクリレート、シクロヘキシルアクリレート、シクロヘキシルメタクリレート、グリシジルアクリレート、グリシジルメタクリレート、エチレングリコールジアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジアクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジアクリレート、トリエチレングリコールジメタクリレート、１，４−ブタンジオールジアクリレート、１，６−ヘキサンジオールアクリレート、テトラエチレングリコールジメタクリレート、１，３−ブチレングリコールジメタクリレート、ポリエチレングリコール（メタ）アクリレート、メトキシポリエチレングリコール（メタ）アクリレート、エトキシポリエチレングリコール（メタ）アクリレート、プロポキシポリエチレングリコール（メタ）アクリレート、イソプロポキシポリエチレングリコール（メタ）アクリレート、フェノキシポリエチレングリコール（メタ）アクリレート、およびエポキシアクリレート類やウレタンアクリレート類のジビニル化合物等をあげることができる。
【００５４】
本発明で使用されるエチレン性不飽和ジカルボン酸モノエステルは、マレイン酸モノアルキルエステル、フマル酸モノアルキルエステル、イタコン酸モノアルキルエステル、シトラコン酸モノアルキルエステル等が例示される。
エチレン性不飽和ジカルボン酸ジエステルは、マレイン酸ジアルキルエステル、フマル酸ジアルキルエステル、イタコン酸ジアルキルエステル、シトラコン酸ジアルキルエステル等が例示される。
【００５５】
エチレン性不飽和カルボン酸アミドの例としては、アクリルアミド、メタクリルアミド、Ｎ−メチルアクリルアミド、Ｎ−メチルメタクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ，Ｎ−ジメチルメタクリルアミド、Ｎ−エチルアクリルアミド、Ｎ−エチルメタクリルアミド、Ｎ，Ｎ−ジエチルアクリルアミド、Ｎ，Ｎ−ジエチルメタクリルアミド、Ｎ−プロピルアクリルアミド、Ｎ−アクリロイルピロリジン、Ｎ−アクリロイルピペリジン、Ｎ−アクリロイルヘキサヒドロアゼピン、Ｎ−アクリロイルモルホリン、Ｎ，Ｎ−ジ−ｎ−プロピルアクリルアミド、Ｎ−ｎ−ブチルアクリルアミド、Ｎ−ｎ−ヘキシルアクリルアミド、Ｎ−ｎ−ヘキシルメタクリルアミド、ジアセトンアクリルアミド、Ｎ−ｎ−オクチルアクリルアミド、Ｎ−ｎ−オクチルメタクリルアミド、Ｎ−tert−オクチルアクリルアミド、Ｎ−ドデシルアクリルアミド、Ｎ−ｎ−ドデシルメタクリルアミド、Ｎ，Ｎ−ジグリシジルアクリルアミド、Ｎ，Ｎ−ジグリシジルメタクリルアミド、Ｎ−（４−グリシドキシブチル）アクリルアミド、Ｎ−（４−グリシドキシブチル）メタクリルアミド、Ｎ−（５−グリシドキシペンチル）アクリルアミド、Ｎ−（６−グリシドキシヘキシル）アクリルアミド、Ｎ，Ｎ’−メチレンビスアクリルアミド、Ｎ，Ｎ’−エチレンビスアクリルアミド、Ｎ，Ｎ’−ヘキサメチレンビスアクリルアミド、Ｎ−メチロールアクリルアミド、Ｎ−メチロールメタクリルアミド、Ｎ−メトキシメチルアクリルアミド、Ｎ−メトキシメチルメタクリルアミド、マレイン酸ジアミド、マレイン酸モノアミド、フマル酸ジアミド、フマル酸モノアミド、イタコン酸ジアミド、イタコン酸ミノアミド等をあげることができる。
【００５６】
前記したエチレン性不飽和カルボン酸以外のアニオン性のエチレン性不飽和化合物には、エチレン性不飽和スルホン酸、およびその他のアニオン性不飽和化合物があげられ、これらの群より選択される一種以上の化合物が用いられる。
【００５７】
エチレン性不飽和スルホン酸としては、ビニルスルホン酸、スチレンスルホン酸、２−アクリルアミド−２−フェニルプロパンスルホン酸、２−アクリルアミド−２−メチルプロパンスルホン酸、アリルスルホン酸、メタリルスルホン酸等のスルホン酸およびそれらのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
その他のアニオン性不飽和化合物としては、リン酸モノ（２−ヒドロキシエチル）メタクリルエステル等のリン酸およびそのアルカリ金属塩、アンモニウム塩、有機アミン塩等をあげることができる。
【００５８】
カチオン性のエチレン性不飽和化合物は、Ｎ，Ｎ−ジメチルアミノエチルアクリレート（ＤＡ）、Ｎ，Ｎ−ジメチルアミノエチルメタクリレート（ＤＭ）、Ｎ，Ｎ−ジエチルアミノエチルアクリレート、Ｎ，Ｎ−ジエチルアミノエチルメタクリレート、Ｎ，Ｎ−ジメチルアミノプロピルアクリルアミド（ＤＭＡＰＡＡ）、Ｎ，Ｎ−ジメチルアミノプロピルメタクリルアミド（ＤＭＡＰＭＡ）等の塩基性ビニル化合物とそれらの塩および、アリルアミン、Ｎ−メチルアリルアミン、２−メチルアリルアミン、ジアリルアミン等のアリルアミン類とそれらの塩等がある。さらには、ＤＡ、ＤＭ、ＤＭＡＰＡＡ、ＤＭＡＰＭＡ等をジメチル硫酸、メチルクロライドやメチルブロマイド等のハロゲン化アルキル類、アリルクロライド、ベンジルクロライドやベンジルブロマイド等のハロゲン化ベンジル類、エピクロヒドリンやエピブロモヒドリン等のエピハロヒドリン類、プロピレンオキシドやスチレンオキシド等のエポキシ類で四級化したビニル化合物や、ジメチルジアリルアンモニウムクロリドなどをあげることができる。
【００５９】
非イオン性のエチレン性親水性不飽和化合物は、Ｎ−ビニル−２−ピロリドン、Ｎ−ビニルオキサゾリドン、Ｎ−ビニル−５−メチルオキサゾリドン、Ｎ−ビニルスクシンイミド、Ｎ−ビニルホルムアミド、Ｎ−ビニルアセトアミド、Ｎ−ビニルカプロラクタム、２−ヒドロキシエチルアクリレート、２−ヒドロキシエチルメタクリレート、３−ヒドロキシプロピルアクリレート、３−ヒドロキシプロピルメタクリレート、２−ヒドロキシプロピルアクリレート、２−ヒドロキシプロピルメタクリレート、アリルアルコール、メタリルアルコール等をあげることができる。
【００６０】
また、エチレン性不飽和カルボン酸エステルおよびビニルエステル化合物以外のエチレン性疎水性不飽和化合物は、芳香族ビニル化合物、シアン化ビニル化合物、ジエン化合物、ビニルアルキルエーテル化合物、その他のビニル化合物、および疎水性アリル化合物からなる群より選択された一種以上の化合物である。
【００６１】
芳香族ビニル化合物は、スチレン、α−メチルスチレン、α−クロロスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−メチルスチレン、ｐ−クロロスチレン、ｏ−クロロスチレン、２，５−ジクロロスチレン、３，４−ジクロロスチレン、ジメチルスチレン、ジビニルベンゼン等をあげることができる。
シアン化ビニル化合物は、アクリロニトリル、メタクリロニトリル、α−クロロアクリロニトリル等をあげることができる。
【００６２】
ジエン化合物は、アレン、ブタジエン、イソプレン等のジオレフィン化合物および、クロロプレン等をあげることができる。
ビニルアルキルエーテル化合物は、ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソプロピルエーテル、ビニルｎ−プロピルエーテル、ビニルイソブチルエーテル、ビニル２−エチルヘキシルエーテル、ビニルｎ−オクタデシルエーテル等をあげることができる。
【００６３】
その他のビニル化合物としては、エチレン、プロピレン、ブテン、α−オレフィン等のオレフィン類、塩化ビニル、塩化ビニリデン、フッ化ビニル、フッ化ビニリデン等のハロゲン化オレフィン類、アジピン酸ジビニル、セバシン酸ジビニル等のジビニルエステル類、ジエチルフマレート、ジメチルイタコネート等のカルボン酸ジアルキルエステル類、マレイミド、Ｎ−フェニルマレイミド、Ｎ−シクロヘキシルマレイミド等をあげることができる。
疎水性のアリル化合物としては、ジアリルイソフタレート、ジアリルテレフタレート、ジエチレングリコールジアリルカーボネート、トリアリルシアヌレート等をあげることができる。
【００６４】
本発明で使用されるカルボキシル基変性ポリビニルアルコールの重合度は、概ね１００〜５０００、好ましくは２００〜３０００、ケン化度はケン化前のビニルエステル化合物に対して６０〜１００モル％、カルボキシル基含量は０．０５〜５０モル％、好ましくは０．１〜３０モル％の範囲にある。
【００６５】
水分散性の合成高分子化合物のなかには、所謂合成ラテックス、エマルションの形態をとるものも含まれる。ポリブタジエンラテックス、スチレン−ブタジエン系ラテックス、アクリロニトリル−ブタジエン系ラテックス、メチルメタアクリレート−ブタジエン系ラテックス、２−ビニルピリジン−スチレン−ブタジエンラテックス、クロロプレンラテックス、イソプレンラテックス、ポリスチレンエマルション、ウレタンエマルション、アクリルエマルション、酢酸ビニル系エマルション、酢酸ビニル−エチレン（ＥＶＡ）系エマルション、アクリレート−スチレン系エマルション、塩化ビニルラテックス、塩化ビニリデンラテックス、エポキシ系エマルション等で称されるもののなかで、カルボキシル基変性されているものが本願の水分散性の合成高分子化合物に該当する。
【００６６】
本発明において、好ましくは用いられるカルボキシル基を含む合成高分子化合物は、エチレン性不飽和化合物の重合体、特に（メタ）アクリルアミド系重合体、カルボキシル基変性ポリビニルアルコール、及びビニルピロリドン系重合体が好ましく、さらに
▲１▼エチレン性の不飽和カルボン酸アミド化合物１〜１００重量％と、共重合可能なエチレン性の不飽和化合物０〜９９重量％との重合体である（メタ）アクリルアミド系重合体、
▲２▼エチレン性の不飽和カルボン酸と、酢酸ビニルとの重合体をケン化して製造されたものであるカルボキシル基変性ポリビニルアルコール、
▲３▼Ｎ−ビニル−２−ピロリドン１〜９９．９重量％と、共重合可能なエチレン性の不飽和化合物０．１〜９９重量％との重合体であるビニルピロリドン系重合体が好ましい。
【００６７】
本発明の水難溶性無機微粒子は、粒径５００ｎｍ以下であれば制限はないが、好ましくは周期表２族元素化合物の微粒子、さらに好ましくは周期表２族元素化合物と有機酸、無機酸およびそれらの塩類から選ばれる１種以上の化合物を反応することにより得られるものである。周期表２族元素には、ベリリウム、マグネシウム、カルシウム、ストロンチウム、バリウム、ラジウムがあり、化学的性質が類似しているため、これらのなかから選ばれる１種以上の元素を使用することができるが、その中でもマグネシウム、カルシウム、ストロンチウム、バリウムが好ましい。さらに好ましくは、カルシウムである。
【００６８】
無機微粒子の合成方法としては、液相合成法が好ましい。いわゆる沈殿法と称される方法であり、水に可溶あるいは難溶な周期表２族元素化合物の水溶液あるいは懸濁液に、有機酸、無機酸およびそれらの塩類を反応することにより水難溶性無機微粒子が合成される。沈殿法と称せられるように、通常は生成した水難溶性無機微粒子は沈澱し、濾過後乾燥あるいは熱分解することにより粉末を得る方法であるが、本発明においては、前記したカルボキシル基を含む水溶性または水分散性の合成高分子化合物を存在させておくことにより、沈澱することなく、コロイド状に均一に分散した分散安定性に優れた有機重合体／無機微粒子分散水溶液となるのである。なぜこのような分散安定性に優れた有機重合体／無機微粒子分散水溶液が生成するのか、必ずしも完全に解明された訳ではないが、無機微粒子を構成する周期表２族元素と合成高分子化合物中のカルボキシル基がイオン的な相互作用により結合することが本発明者らの実験結果から示唆されており、そのために結晶成長が抑制され、５００ｎｍ以上に粒子径が増大しないとともに、結合した高分子化合物の保護コロイド的な作用のために粒子間の凝集を抑制していることが理由としてあげられる。
【００６９】
本発明の水難溶性無機微粒子は、２０℃における水への溶解度が概ね３．０（重量％）以下のものであり、水不溶性無機微粒子も含まれる。周期表２族元素の種類により異なり、例えばマグネシウムの場合、水酸化物、フッ化物、炭酸塩、シュウ酸塩、リン酸塩など、カルシウムの場合、フッ化物、硫酸塩、リン酸塩、炭酸塩、ケイ酸塩、シュウ酸塩、水酸化物など、ストロンチウムの場合、フッ化物、炭酸塩、シュウ酸塩、硫酸塩、リン酸塩、水酸化物など、バリウムの場合、炭酸塩、硫酸塩、リン酸塩、シュウ酸塩などが例示される。
【００７０】
本発明の水難溶性無機微粒子の合成に使用される周期表２族元素化合物の例としては、酢酸マグネシウム、炭酸マグネシウム、塩化マグネシウム、ケイフッ化マグネシウム、水酸化マグネシウム、酸化マグネシウム、硝酸マグネシウム、硫酸マグネシウム、酢酸カルシウム、リン酸二水素カルシウム、乳酸カルシウム、クエン酸カルシウム、水酸化カルシウム、炭酸カルシウム、塩化カルシウム、硝酸カルシウム、硫酸カルシウム、チオ硫酸カルシウム、水酸化ストロンチウム、炭酸ストロンチウム、硝酸ストロンチウム、塩化ストロンチウム、酢酸バリウム、塩化バリウム、硝酸バリウム、硫酸バリウム、水酸化バリウム、フッ化バリウムなどから選ばれる１種以上の化合物があげられる。
【００７１】
本発明で使用される無機酸、有機酸およびそれらの塩類は、周期表２族元素化合物と反応して水難溶性無機微粒子を生成するものであればよい。なかでもオキソ酸とハロゲン化水素酸およびそれらの塩類が好ましい。
【００７２】
オキソ酸の例としては、ホウ酸、メタホウ酸、炭酸、イソシアン酸、雷酸、オルトケイ酸、メタケイ酸、硝酸、亜硝酸、リン酸（オルトリン酸）、ピロリン酸（二リン酸）、メタリン酸、ホスホン酸（亜リン酸）、ジホスホン酸（二亜リン酸）、ホスフィン酸（次亜リン酸）、硫酸、二硫酸、チオ硫酸、亜硫酸、クロム酸、二クロム酸、過塩素酸、ギ酸、酢酸、プロピオン酸、酪酸、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、マレイン酸、フマル酸、乳酸、リンゴ酸、酒石酸、安息香酸、フタル酸などがあげられる。
【００７３】
ハロゲン化水素酸の例には、フッ化水素酸、塩化水素酸、臭化水素酸、ヨウ化水素酸などがある。
オキソ酸とハロゲン化水素酸の塩類の例としては、それらのアルカリ金属塩、アルカリ土類金属塩、アンモニウム塩、有機アミン塩などがある。
【００７４】
動物骨殻の無機成分として、貝殻等に含まれる炭酸カルシウムや骨、歯、魚燐等に含まれるリン酸カルシウムは、生体内に見られる有機／無機複合体の主要な構成成分であり、本発明の水難溶性微粒子の中でも、これらのリン酸カルシウムや炭酸カルシウムをはじめとしたカルシウム化合物は有機物との親和性が高いため、特に好適に使用される。
【００７５】
水難溶性無機微粒子がリン酸カルシウムの場合について以下詳細に記述するが、基本的な操作などに関しては、カルシウム化合物の場合使用する原料が異なるだけであり、同様に実施すれば良い。また、その他２族元素化合物の場合も、使用する原料が異なるだけであり、同様にすれば良い。
本発明の分散水溶液中に含まれるリン酸カルシウムは、リン酸に由来する部分とカルシウム原子の合計が５０重量％以上含まれるものである。例としてはヒドロキシアパタイト、フッ素アパタイト、塩素アパタイト、炭酸含有アパタイト、マグネシウム含有アパタイト、鉄含有アパタイト等のアパタイト化合物、リン酸三カルシウム等が挙げられる。
【００７６】
本発明のリン酸カルシウムに含まれるアパタイト化合物は、基本組成がＭ_x（ＲＯ₄）_yＸ_zで表される。Ｍサイトがカルシウムイオン（Ｃａ²⁺）、ＲＯ₄サイトがリン酸イオン（ＰＯ₄ ^3-）、Ｘサイトが水酸化イオン（ＯＨ^-）の場合には、ｘ＝１０、ｙ＝６、ｚ＝２となり、一般的にヒドロキシアパタイトと呼ばれる化合物である。Ｍ、ＲＯ₄、Ｘの各サイトは、種々のイオン等と置換が可能であり、また、空孔ともなり得るものである。置換量および空孔量は、そのイオン等の種類により異なるが、リン酸に由来する部分とカルシウム原子の合計が５０重量％以上含まれていれば、他のイオン等と置換されていても、空孔であっても差し支えない。
【００７７】
リン酸に由来する部分とカルシウム原子の合計が５０重量％を下回るとリン酸カルシウムとしての特性が失われることがあるために好ましくない。Ｍサイトは基本的にＣａ²⁺であるが、置換可能なイオン種の例として、Ｈ⁺、Ｎａ⁺、Ｋ⁺、Ｈ₃Ｏ⁺、Ｓｒ²⁺、Ｂａ²⁺、Ｃｄ²⁺、Ｐｂ²⁺、Ｚｎ²⁺、Ｍｇ²⁺、Ｆｅ²⁺、Ｍｎ²⁺、Ｎｉ²⁺、Ｃｕ²⁺、Ｈｇ²⁺、Ｒａ²⁺、Ａｌ³⁺、Ｆｅ³⁺、Ｙ³⁺、Ｃｅ³⁺、Ｎｄ³⁺、Ｌａ³⁺、Ｄｙ³⁺、Ｅｕ³⁺、Ｚｒ⁴⁺等があげられる。ＲＯ₄サイトは基本的にＰＯ₄ ^3-であるが、置換可能なイオン種の例として、ＳＯ₄ ^2-、ＣＯ₃ ^2-、ＨＰＯ₄ ^2-、ＰＯ₃Ｆ^2-、ＡｓＯ₄ ^3-、ＶＯ₄ ^3-、ＣｒＯ₄ ^3-、ＢＯ₃ ^3-、ＳｉＯ₄ ^4-、ＧｅＯ₄ ^4-、ＢＯ₄ ^5-、ＡｌＯ₄ ^5-、Ｈ₄Ｏ₄ ^4-等があげられる。Ｘサイトに入るイオン種や分子の例として、ＯＨ^-、Ｆ^-、Ｃｌ^-、Ｂｒ^-、Ｉ^-、Ｏ^2-、ＣＯ₃ ^2-、Ｈ₂Ｏ等があげられる。
【００７８】
本発明の分散水溶液中に含まれるリン酸カルシウムの粒径は５００ｎｍ以下である。粒径が５００ｎｍを越えると粒子が分散水溶液から沈降分離しやすくなり、分散水溶液の安定性に欠けるため適当ではない。また、リン酸カルシウム結晶構造についてはいかなるものでもよく、非晶質でもよい。さらに、リン酸カルシウムの形状についても特に制限はなく、球形、針状、柱状、不定形等いかなる形状でもかまわない。粒径分布についても、粒径が５００ｎｍ以下であれば特に制限はない。ここで用いる粒径とは、粒子の長軸径を示す。
【００７９】
カルボキシル基を含む水溶性または水分散性の高分子化合物／リン酸カルシウム微粒子分散水溶液を製造する方法（複合化）のなかで、分散安定性の優れた分散液を得るためには、リン酸カルシウムをカルボキシル基を含有する水溶性または水分散性の高分子存在下に製造するのが特に好ましく、その点に本発明の特徴がある。リン酸カルシウムの製造方法は、カルボキシル基を含む水溶性または水分散性の高分子化合物存在下に製造可能な方法であれば、いかなる製造方法でもかまわないが、所謂湿式法（液相法／沈殿法）が好ましい。湿式法は、カルシウム化合物（懸濁）水溶液とリン酸あるいはリン酸塩水溶液を混合することによりリン酸カルシウムを合成する方法であり、一般的には両液を同時滴下か、一方の溶液の中へ他方の溶液を滴下する方式がとられる。滴下時間については特に制限はないが、概ね５分〜２４時間である。反応は滴下終了後、必要に応じて熟成させる。
【００８０】
カルボキシル基を含む水溶性または水分散性の高分子化合物はリン酸カルシウムが生成する反応液中に存在させればよく、カルシウム化合物（懸濁）水溶液、リン酸あるいはリン酸塩水溶液いずれかに混合しておいてもよいし、両方に混合しておいてもよい。また、両者とは別に独立して反応器の中へ連続的あるいは断続的に添加してもよい。但し、未ケン化部含量が多い（概ね５〜６０モル％）カルボキシル基変性ポリビニルアルコールを複合化する場合など、アルカリ加水分解反応をうける成分を高分子化合物の中に含有するものに関しては、特に原料として水酸化カルシウム等のアルカリ性の高い物質をカルシウム源として用いる場合には注意が必要である。例えば、水酸化カルシウムとカルボキシル基変性ポリビニルアルコールとを混合しておくと、未ケン化部の加水分解反応が副反応として生じるため問題となることがある。このような場合には、水酸化カルシウムが加水分解反応で消費される分量のリン酸が過剰になるため反応液のｐＨ低下を招き、リン酸カルシウムの生成が不完全になるとともに、複合化が不良になり、反応液の分離、沈降を生じることがある。この問題を解決するには、水酸化カルシウムとカルボキシル基変性ポリビニルアルコールを分けて、両者あるいは一方を滴下すればよく、リン酸カルシウムの反応が優先するため副反応を抑えることができる。この方法により未ケン化部を含有するカルボキシル基変性ポリビニルアルコール／リン酸カルシウム分散水溶液が製造できる。ケン化により生じる酢酸ナトリウム等の影響が問題にならない場合には、未ケン化部に相当する量のアルカリを添加して、予めケン化反応を行った後に複合化反応を行ってもよいが、不純物による着色などの影響を抑えることができるため、完全ケン化タイプのカルボキシル基変性ポリビニルアルコールを用いるほうが好ましい。しかしながら、（メタ）アクリルアミド系重合体のように、加水分解反応によりカルボキシル基を生成するものは、複合化反応の際に加水分解反応をむしろ積極的に起こしても良いことがある。
【００８１】
合成に用いるカルシウム塩としては、塩化カルシウム、硝酸カルシウム、酢酸カルシウム、水酸化カルシウム、炭酸カルシウム、硫酸カルシウム・２水和物等があげられる。リン酸塩としては、リン酸２水素アンモニウム、リン酸水素２アンモニウム、およびアンモニウム塩以外のこれらのナトリウム、カリウム塩等があげられる。目的とする化合物以外の、反応に伴ない副生する有機あるいは無機塩は、用途によっては除去する必要があり、その際は透析など既知の方法で脱塩する。リン酸カルシウムを目的化合物とする場合には、水酸化カルシウムとリン酸を原料にすれば副生塩は発生しないため特に好ましい。また、リン酸カルシウムの中でもアパタイト構造をとるものはその構造の柔軟さから前述のように各種イオンと置換できることが知られており、必要に応じてカルシウムおよびリン酸以外のイオン種を含む化合物を併用することもできる。
【００８２】
カルボキシル基を含む水溶性または水分散性の高分子化合物とリン酸カルシウムの重量比は１０：９０〜９９．９９：０．０１、好ましくは２０：８０〜９９．９９：０．０１、さらに好ましくは３０：７０〜９９：１の範囲である。リン酸カルシウムの量が０．０１％より少ないとリン酸カルシウムを添加する効果が乏しく、９０％を越えると分散安定性が不良で沈降、分離を起こしやすくなり、均一な複合体を形成できなくなるため好ましくない。
【００８３】
通常は反応溶液を所定温度に保つことにより反応を行う。反応中同一温度に保つ必要はなく、反応の進行にともない適宜変えてよく、必要に応じて加熱あるいは冷却しながら行う。反応温度により生成するリン酸カルシウム粒子の大きさが変化するため、反応温度を変えることにより粒径を変えることができ、その結果分散水溶液から作成されるフイルムの透明性を加減することも可能である。反応温度は概ね５〜９５℃の範囲にある。反応器内の雰囲気は特に限定はなく通常は空気中で行われるが、リン酸カルシウムの組成をコントロールするには窒素ガスのような不活性ガスで置換した方がよい。合成時間は特に限定はないが、滴下、熟成時間を合わせて概ね１〜１２０時間である。
【００８４】
攪拌方法については、均一に混合される方法であれば特に制限はなく、例として回転による方法、超音波による方法等があげられる。攪拌羽根を用いたバッチ式の反応容器を用いる場合、攪拌羽根の形状や溶液粘度等に影響されるため一概にはいえないが、攪拌速度は概ね３０〜１００００ｒｐｍの範囲である。
【００８５】
反応溶媒としては水を用いるが、メタノール、エタノール、イソプロパノール、アセトン、エチレングリコール、プロピレングリコール、グリセリン等の有機溶剤を併用してもよい。
【００８６】
合成する際の濃度は特に制限はないが、リン酸カルシウムとカルボキシル基を含む水溶性または水分散性の高分子化合物の固形分を合わせて概ね０．５〜６０重量％の範囲であり、好ましくは１〜５０重量％の範囲にある。５０重量％を越えると分散液の粘度が高くなり、取り扱いが困難となる場合がある。
【００８７】
リン酸カルシウムは、反応時のｐＨにより生成するリン酸カルシウムの種類が異なるため、特定の種を製造する場合にはｐＨを調整しながら行うこともある。ｐＨ調整は、アンモニアガス、アンモニア水、水酸化ナトリウム、水酸化カリウム等により行うことができる。特に、▲１▼目的化合物がｐＨ変化により溶解する場合、▲２▼カルボキシル基の解離状態変化により複合体が分離するような場合には厳密にｐＨ調整を行う必要がある。例えば、ヒドロキシアパタイト（リン酸カルシウム）の場合には、反応後は▲２▼の理由からｐＨ５以下にならないように適宜アルカリを添加して調整する。
【００８８】
かくして得られる安定性に優れるカルボキシル基を含む水溶性または水分散性の高分子化合物／リン酸カルシウム微粒子分散水溶液は、均一なエマルション溶液であり、長時間静置しておいても沈降、分離を起こさない。ここで言う安定性に優れるものとは、製造直後に混在する沈降粒子（一夜放置で沈降）を除いて、製造後沈降あるいは分離する固形物重量が、１ケ月経過した時点で１重量％以下のもの、あるいは２０００ｒｐｍで１０分間遠心処理を行っても沈降や分離を起こさないものを言う。
【００８９】
水難溶性無機微粒子が炭酸カルシウムの場合にもリン酸カルシウムと同様の方法で製造される。この場合には、カルシウム源としては、リン酸カルシウムと同一の原料が使用でき、炭酸源には、炭酸ガス、炭酸ナトリウム、炭酸水素ナトリウム、炭酸カリウム、炭酸水素カリウム、炭酸アンモニウムなどが適宜使用される。リン酸カルシウムの場合と同様に、副生塩を発生させないためには、水酸化カルシウムと炭酸（ガス）の組み合わせが好ましい。
【００９０】
本発明の透明性に優れるカルボキシル基を含む水溶性または水分散性の高分子化合物／リン酸カルシウム複合体は、このようにして得られる分散安定性に優れるカルボキシル基を含む水溶性または水分散性の高分子化合物／リン酸カルシウム微粒子分散溶液から水を除去することにより固形化される。複合体は用途により、公知の方法や機器を用いてフィルム状、シート状、粉末状、発泡体状、糸状など任意の形状に加工することができる。
また、温度変化により物理的に架橋構造をつくる方法や、架橋剤を用いて化学的な結合（イオン結合、共有結合）で架橋構造をつくる方法により、ゲル状の複合体に加工することも可能である。
【００９１】
例えば、フィルムに加工する場合には、分散水溶液をそのまま、あるいは濃縮処理やｐＨ調整、必要に応じてエチレングリコールやグリセリン等の公知の可塑剤や、架橋剤、増粘剤、充填剤、着色剤、酸化防止剤、紫外線吸収剤、熱安定剤等の添加剤を混合した後に、ガラス、石英、金属、セラミックス、プラスチック、ゴム等の基板、ロール、ベルト等の上に上記の安定な分散液を塗布・製膜し、必要に応じて加熱、減圧、送気、赤外線照射、極超短波照射等の処理を行って水および／または水系の溶剤を蒸発させることにより製造することができる。塗布方法は特に制限はなく、流し塗り法、浸漬法、スプレー法等があり、バーコーター、スピンコーター、ナイフコーター、ブレードコーター、カーテンコーター、グラビアコーター、スプレーコーター等の公知の塗工機を使用できる。塗布厚み（乾燥前の厚み）は概ね１μｍ〜１０ｍｍで、塗布法の選択により任意に厚みを設定できる。水および／または水系の溶剤を蒸発させる温度は０〜１５０℃の温度範囲で行い、常圧あるいは減圧下に行う。その際に乾燥空気あるいは乾燥窒素を流通させて乾燥時間を短縮することができる。さらに、耐水性を付与する等の目的で架橋反応を促進する場合には、４０〜２００℃で数秒〜数十分間熱処理を行う。このフィルムを基材から剥がして使用する場合には、プラスチック製の基材を用いると離型性が良好であるが、その他の基材を用いる場合にも必要に応じて各素材に公知の離型剤を予め塗布するとよい。このようにして製造されるフィルムは透明性に優れる特徴を有する。これは、リン酸カルシウム微粒子のサイズが可視光の波長領域以下であり、個々の粒子が凝集を起こすことなくポリマーマトリックス中に均一に分散していることを示す。透明性については、４００ｎｍと７００ｎｍでの可視光透過率により定量的に評価できる。ここでいう透明性に優れるとは膜厚が３０〜３００μｍにおける７００ｎｍ波長の光透過率が５０％以上を示すものをいう。このフイルムは水分を吸収すると白濁し、乾燥すると透明になる。この変化は可逆的であり、透明性に優れるとの表現は乾燥条件下（含水量１０重量％以下）についての記述である。
【００９２】
さらに、この透明なフイルムは架橋など特別な処理を行わないものは水に再分散する。再分散性は特に（メタ）アクリルアミド系重合体に顕著である。なぜこのようにいったんフイルム化したものが再分散するなど、分散安定性にきわめて優れるのか理由は定かではないが、前述したような高分子と粒子間でのイオン的な結合を介在した吸着作用と、保護コロイド的な作用の存在を裏付けるものであると考えられる。
【００９３】
フィルムは非常に親水性が高いため、耐水性に問題が生じる場合があるが、このような場合、(１)物理的に水や湿気の侵入を防ぐ方法と、(２)フィルム作製時に耐水性を付与する方法がある。(１)は、疎水性のフィルムをラミネートする方法が有効である。(２)は、カルボキシル基を含む水溶性または水分散性の高分子化合物／無機微粒子の水分散溶液自身に架橋反応性を持たせる方法と、耐水化剤を添加する方法がある。具体的には、前者は(Ｉ)カルボキシル基を含む水溶性または水分散性の高分子化合物を製造する際に共重合により架橋性の官能基を導入する方法、(II)カルボキシル基を含む水溶性または水分散性の高分子化合物と反応可能な架橋剤を添加する方法がある。(Ｉ)では官能基として、カルボキシル基、アミノ基、エポキシ基、水酸基、オキサゾリン基などが用いられ、これらの官能基同士の反応あるいは多価金属イオンによる架橋反応により耐水性がもたらされる。(II)は、ホルマリンや尿素−ホルマリン樹脂、ポリアミド−ポリアミン樹脂やそれらの変性物などが挙げられる。また、後者は分散水溶液に硬化性のエマルション樹脂を混合する方法などがあり、公知のアクリル系、ポリエステル系、ポリウレタン系のエマルションが利用できる。
【００９４】
カルボキシル基を含む水溶性または水分散性の高分子化合物／無機微粒子の水分散溶液から複合体を粉末化する方法は、フィルム加工と同様に複合体の分散水溶液をそのまま、あるいは濃縮処理やｐＨ調整、必要に応じてエチレングリコールやグリセリン等の公知の可塑剤や、架橋剤、増粘剤、充填剤、着色剤、酸化防止剤、紫外線吸収剤、熱安定剤等の添加剤を混合した後に、スプレードライ、凍結乾燥のように溶媒を分散液から直接気化する方法や、あるいは水と混和するが複合体を溶解しないメタノールのような有機溶剤または硫酸ナトリウムのような塩析効果の高い化合物を用いることにより固体分離処理を行い、乾燥後粉末化する方法も可能であるが、本発明の主旨から言えば前者の方が好ましい。
【００９５】
その他の形状加工についても、フィルム加工と同様に、複合体の分散水溶液をそのまま、あるいは濃縮処理やｐＨ調整、必要に応じてエチレングリコールやグリセリン等の公知の可塑剤や、架橋剤、増粘剤、充填剤、着色剤、酸化防止剤、紫外線吸収剤、熱安定剤等の添加剤を混合した後に、公知の方法により実施できる。
【００９６】
本発明のカルボキシル基を含む水溶性または水分散性の高分子化合物／無機微粒子複合体は、特にポリビニルアルコールやポリビニルピロリドンなどに関しては安全性の高いポリマー材料であることが知られており、その複合化相手がリン酸カルシウムや炭酸カルシウムの場合には、「生体親和性の高い粒子がナノメートルサイズで均一に混合分散しているポリマー複合材料」という点で特徴づけられ、種々の用途がある。これらの複合体は前述のように種々の形状に加工可能である点から、特に医用あるいは化粧用材料として非常に有用な材料である。医用材料としては人工骨材料、骨充填剤、歯科材料、ＤＤＳ担体、皮膚疾患治療薬等に利用できる。さらに、前述のようにこれらの複合体フィルムは水を吸収すると白濁し、乾燥すると透明なフィルムに戻るという特徴も有する。これは粒子水和に伴なう散乱によるものであり、フイルムに限った現象ではない。この性質を利用すれば、ＵＶ遮光性の高い化粧品や湿度により透明性が可逆的に変化する窓材、湿度センサーなどへの利用が可能である。
【００９７】
このように、前記分散安定性に優れる高分子化合物／無機微粒子分散水溶液を含有するものや透明性に優れる高分子化合物／無機微粒子複合体を含有する化粧品も本発明の１つである。
【００９８】
本発明のカルボキシル基を含む水溶性または水分散性の高分子化合物／無機微粒子複合体は、複合前のポリマー単独のフイルムに比べて、引張強度、硬度、熱特性、ガスバリア性などが向上する。例えば、ポリビニルアルコールはガスバリア性の高い材料として知られているが、それに比べても複合化によりバリア性が大幅に向上する。これらの特性を利用するには、耐水性に劣るポリビニルアルコールを中間層とした多層フイルムとすることで解決できるが、耐水性があまり問題とならない用途では必要に応じて耐水化処理を施すことで表面層にコートしてもよい。また、フイルム自体の強度が上がる利点もあるが、これを種々の基材に塗布、含浸させることにより、基材の強度を向上させる目的でも使用することができ、それらの中でも、紙に適用した場合に有用であり、製紙用薬品も本発明の１つである。
【００９９】
本発明の製紙用薬品は、前記分散安定性に優れる高分子化合物／無機微粒子分散水溶液から得られるものである。また、本発明の製紙用薬品は、カルボキシル基を含む水溶性または水分散性の合成高分子化合物（Ａ）と、周期表２族元素化合物と有機酸、無機酸およびそれらの塩類から選ばれる１種以上の化合物を反応させて得られた粒径５００ｎｍ以下の水難溶性無機微粒子（Ｂ）とを、（Ａ）：（Ｂ）＝１０：９０〜９９．９９：０．０１（重量比）で含有してなる製紙用薬品である。
【０１００】
本発明の製紙用薬品を使用して得られる紙は、紙力性能が向上する。特に、本発明の製紙用薬品を紙の表面に塗工（外添）することにより、紙力強度が大幅に向上する。紙に塗工する際の塗工液濃度は、０．０１〜２０．０重量％、好ましくは０．１０〜１０．０重量％の範囲にある。その塗工量は、０．００１〜２０．０g/m²、好ましくは０．００５〜１０．０g/m²の範囲にある。紙への塗工は、含浸、サイズプレス、ゲートロールコーター、カレンダー、ブレードコーター、スプレー等の一般的な方法が用いられる。塗工後の乾燥温度は、水が蒸発する温度であればよく、好ましくは１００℃から１８０℃の範囲にある。さらに本発明の製紙用薬品は、澱粉系、カルボキシメチルセルロース系、ＰＶＡ系、ＰＡＭ系等の従来公知の表面塗工用の薬品類と組み合わせることにより、表面強度や内部強度を一層向上させることもできる。
【０１０１】
本発明の製紙用薬品は、硫酸アルミニウム、塩化アルミニウム、アルミン酸ナトリウムや、ポリエチレンイミン、ポリアクリルアミドのマンニッヒ変性物やホフマン変性物、ポリアルキレンポリアミン、カチオン化澱粉などのカチオン基を持つ水溶性高分子などとの相互作用によりパルプへの定着が可能であり、抄紙用の内添薬品としても利用可能である。内添薬品として使用する場合には、パルプ重量に対して０．０１〜５．０重量％、好ましくは０．０５〜２．０重量％添加され、種箱やマシンチェストなどの通常の内添薬品と同様の場所で添加すればよい。
本発明の製紙用薬品は必要に応じて、消泡剤、防腐剤、防錆剤、防滑剤などを混合する、あるいは使用時に併用してもよい。
【０１０２】
リン酸カルシウム、炭酸カルシウムは生体に限らず有機物との親和性が高いことが知られている。本発明の複合体中のナノメートルサイズのリン酸カルシウム微粒子は従来のものと異なって凝集構造を作らずに複合体中に均一に分散していることから、比表面積は大幅に向上し、水中に含まれる有機物との相互作用が大きくなるため、例えばインクジェット記録材用途などにも好適に使用することができ、インクジェット記録シート薬品も本発明の１つてある。
【０１０３】
本発明のインクジェット記録シート用薬品は、前記分散安定性に優れる高分子化合物／無機微粒子分散水溶液から得られるものである。また、本発明のインクジェット記録シート用薬品は、カルボキシル基を含む水溶性または水分散性の合成高分子化合物（Ａ）と、周期表２族元素化合物と有機酸、無機酸およびそれらの塩類から選ばれる１種以上の化合物を反応させて得られた粒径５００ｎｍ以下の水難溶性無機微粒子（Ｂ）とを、（Ａ）：（Ｂ）＝１０：９０〜９９．９９：０．０１（重量比）で含有してなるインクジェット記録シート用薬品である。
本発明のインクジェット記録シート用薬品は、従来使用されてきた無機填料がもつ長期保存に対して紙が黄色く変色する黄変性の問題に対して、非常に優れた特長をもつ。
【０１０４】
本発明のインクジェット記録シート用薬品は、シート基材に塗布することにより耐黄変性に優れたインクジェット記録用シートを製造することができる。シート基材としては特に制限はなく、パルプおよびパルプを主原料とした紙、再生紙、合成紙、布、不織布、ポリオレフィンやアクリル系ポリマー、ポリエステルを主原料にしたフイルムや板、ガラス板等があげられる。
【０１０５】
本発明のインクジェット用記録シート用薬品は、単独でも使用し得る以外に、耐黄変性を損なわない範囲で必要に応じて公知の無機填料、有機填料、バインダー、その他各種添加剤を使用することができる。無機填料としては炭酸カルシウム、カオリン、クレー、タルク、マイカ、硫酸カルシウム、硫酸バリウム、二酸化チタン、酸化亜鉛、硫化亜鉛、炭酸亜鉛、サチンホワイト、ゼオライト、スメクタイト、ケイソウ土、ケイ酸カルシウム、ケイ酸アルミニウム、非晶質シリカ、アルミナ等があげられ、有機填料としてはスチレン系や尿素樹脂系のプラスチックピグメント等があげられる。バインダーとしてはポリビニルアルコール、カルボキシメチルセルロースやヒドロキシエチルセルロース等のセルロース誘導体、ポリビニルピロリドン、水溶性アクリル樹脂、カゼイン、大豆蛋白、ゼラチン、澱粉、スチレン−ブタジエン系ラテックスやアクリル系エマルション等があげられる。その他の添加剤としてはインク定着剤、耐水化剤、ドット調整剤、湿潤剤、ｐＨ調整剤、蛍光増白剤、酸化防止剤、紫外線吸収剤、防腐剤、消泡剤、増粘剤、顔料分散剤、離型剤などがあげられる。
【０１０６】
本発明のインクジェット記録シート用薬品を基材上に塗布する手段としては特に制限はなく、目的に応じて適宜選択することができる。各種公知の方法、例えばブレードコーター、ロールコーター、エアーナイフコーター、バーコーター、カーテンコーター、スプレーコーター、サイズプレス、含浸等の方法が用いられる。必要に応じてスーパーカレンダー、ソフトカレンダー等の平滑化装置で平滑化処理することもできる。塗工層は用途、目的に応じて２層以上の積層構造にしてもよい。塗工層の塗布量については特に制限はないが、複合体の固形分で３〜３０g/m²が好ましい。３０g/m²より多く塗布しても特性が更に向上するものではなく、また、３g/m²より少ないとインク吸収性が不十分となるおそれがある。
【０１０７】
本発明のカルボキシル基を含む水溶性または水分散性の高分子化合物／リン酸カルシウム複合体は透明性が高い点と、有機体・生体に対して親和性の高いリン酸カルシウムを幅広い比率で含有させることができる特徴を持つことから、上記以外にも塗料、接着剤、顔料バインダー、セラミックス粘結剤、経糸剤、乳化剤、クロマトグラフィー用充填剤、フィルター材料、樹脂改質剤、排水処理剤、抗菌剤、難燃剤、湿度や炭酸ガス等のセンサー材料、細胞培養用基材、分離膜、食品添加剤等の広い分野にわたって使用することができる。
【０１０８】
【実施例】
以下、実施例で本発明を詳細に説明するが、本発明はこれらの実施例に限定されるものではない。また、以下の例において用いる％は特記のない限り重量基準を示す。
粘度は25℃においてＢ型粘度計〔（株）トキメック社製〕により計測した値である。
Ｘ線回折による分析は、ＲＩＮＴ Ｘ-ray Diffractometer （理学電機社製）を用いて行った。
ＦＴ−ＩＲ測定は、日本分光社製のＦＴ／ＩＲ−８３００フーリエ変換赤外分光光度計を用いて行った。
光透過率測定は、島津自記分光光度計ＵＶ−２２００Ａ（島津製作所社製）を用いて行った。
透過型電子顕微鏡（ＴＥＭ）観察は、Ｈ−３００型日立電子顕微鏡（日立製作所社製）およびＪＥＭ−２０１０型透過型電子顕微鏡（日本電子社製）を用いて行った。
超微小硬度測定は、島津ダイナミック超微小硬度計ＤＵＨ−２０１型（島津製作所社製）を用いて行った。
【０１０９】
〔重合体製造例１〕
攪拌機、還流冷却管、温度計、窒素ガス導入管を備えた４つ口フラスコにアクリルアミド30.00g、次亜リン酸ナトリウム一水和物0.15g 、蒸留水266.85g を混合溶解し、ｐＨを4.5 に調整した。窒素ガスを液面上部から一定流量で流しながら溶液の温度を80℃に調整した後、過硫酸アンモニウム0.30g を溶解した水溶液3.0gを添加し、３時間重合反応を行なった。30℃以下に冷却して反応を終了させ、25℃におけるブルックフィールド粘度が114.4mPa・s の（メタ）アクリルアミド系重合体（重合体Ａ）水溶液（不揮発分11.12％）を得た。
重量平均分子量は、337,000 であった。
【０１１０】
〔重合体製造例２〜５〕
アクリルアミド、共重合モノマー、重合開始剤、連鎖移動剤などを表１に記載した量を使って重合体製造例１と同様に反応を行い、（メタ）アクリルアミド系重合体（重合体Ｂ〜Ｅ）水溶液を得た。
重合結果は表１に記載した。
【０１１１】
〔重合体製造例６〕
攪拌機、還流冷却管、温度計、窒素ガス導入管を備えた４つ口フラスコにＮ，Ｎ−ジメチルアクリルアミド（ＤＭＡ）30.00g、次亜リン酸ナトリウム一水和物0.15g 、蒸留水266.85g を混合溶解し、ｐＨを4.5 に調整した。窒素ガスを液面上部から一定流量で流しながら溶液の温度を80℃に調整した後、過硫酸アンモニウム0.30g を溶解した水溶液3.0gを添加し、３時間重合反応を行なった。30℃以下に冷却して反応を終了させ、25℃におけるブルックフィールド粘度が37.5mPa ・ s の（メタ）アクリルアミド系重合体（重合体Ｆ）水溶液（不揮発分10.58％）を得た。
重量平均分子量は、232,200 であった。
【０１１２】
〔重合体製造例７〜２０〕
ＤＭＡ、共重合モノマー、重合開始剤、連鎖移動剤などを表１に記載した量を使って重合体製造例６と同様に反応を行い、（メタ）アクリルアミド系重合体（重合体Ｇ〜Ｐ：組成の同じ物は▲１▼等の添字で区別した）を得た。
重合結果は表１に記載した。
【０１１３】
〔重合体製造例２１〕
攪拌機、還流冷却管、温度計、窒素ガス導入管を備えた４つ口フラスコにＮ−ビニル−２−ピロリドン（ＮＶＰ）22.12g、イタコン酸2.88g、次亜リン酸ナトリウム一水和物0.13g 、蒸留水218.84g を混合溶解し、ｐＨを4.5 に調整した。窒素ガスを液面上部から一定流量で流しながら溶液の温度を80℃に調整した後、４，４’−アゾビス（２−シアノ吉草酸）（Ｖ−５０１：和光純薬社製）0.25g を溶解した水溶液2.5gを添加し、３時間重合反応を行なった。30℃以下に冷却して反応を終了させ、25℃におけるブルックフィールド粘度が54.5mPa ・ s のビニルピロリドン系重合体（重合体Ｒ）水溶液（不揮発分11.28％）を得た。
重量平均分子量は、251,000 であった。
【０１１４】
〔重合体製造例２２〜２４〕
ＮＶＰ、共重合モノマー、重合開始剤、連鎖移動剤などを表２に記載した量を使って重合体製造例２１と同様に反応を行い、ビニルピロリドン系重合体（重合体Ｓ〜Ｕ）を得た。
重合結果は表２に記載した。
【０１１５】
〔重合体製造比較例１〕
攪拌機、還流冷却管、温度計、窒素ガス導入管を備えた４つ口フラスコにＮ−ビニル−２−ピロリドン（ＮＶＰ）30.00g、蒸留水268.50g を混合溶解し、ｐＨを4.5 に調整した。窒素ガスを液面上部から一定流量で流しながら溶液の温度を80℃に調整した後、２，２’−アゾビス（２−アミジノプロパン）二塩酸塩（Ｖ−５０：和光純薬社製）0.15g を溶解した水溶液1.5gを添加し、３時間重合反応を行なった。30℃以下に冷却して反応を終了させ、25℃におけるブルックフィールド粘度が36.0mPa ・ s のビニルピロリドン系重合体（重合体Ｖ）水溶液（不揮発分10.57％）を得た。
重量平均分子量は、149,800 であった。
【０１１６】
〔重合体製造比較例２〜４〕
ＮＶＰ、共重合モノマー、重合開始剤、連鎖移動剤などを表２に記載した量を使って重合体製造比較例１と同様に反応を行い、ビニルピロリドン系重合体（重合体Ｗ〜Ｙ）を得た。
重合結果は表２に記載した。
【０１１７】
〔複合化実施例〕
重合体とリン酸カルシウムとの複合化は以下の複合化実施例に示した。
水酸化カルシウム懸濁液に重合体とリン酸の混合液をフィードする方法をＩ、水酸化カルシウムと重合体の混合懸濁液にリン酸をフィードする方法をIIと表し、表３〜５に示した。
【０１１８】
得られた有機重合体／リン酸カルシウム微粒子分散溶液の安定性は製造後１日静置した後の分散状態を目視で確認する方法（静置分散性）と、２，０００rpmで１０分間遠心処理を行った後の分散状態を目視で確認する方法（遠心分散性）を、それぞれ１〜５の５段階で評価した。
１：分離なし
２：分離なし、微量初期沈降物あり
３：分離上澄液＜１０％
４：分離上澄液１０〜２５％
５：分離上澄液＞２５％
なお、２はごく微量、製造一夜放置後に沈降物が認められるもので、必要に応じて濾過処理を行うことで本発明の分散水溶液となる。１、２が本発明の安定な分散溶液に含まれる領域である。
【０１１９】
＜（メタ）アクリルアミド系重合体との複合化（１）＞
〔複合化実施例１〕
攪拌機、温度計を備えた丸底セパラブルフラスコに水酸化カルシウム 4.61g、蒸留水 145.39gを入れ、激しく攪拌して懸濁液とした。懸濁液の温度を40℃に調整し、攪拌速度200rpmで攪拌しながら、11.1％リン酸水溶液33.01g、ｐＨを10.0に調整した重合体製造例１で得られた水溶性ポリマー（重合体Ａ）水溶液56.21g、蒸留水10.78gを混合溶解した水溶液を、ミクロチューブポンプを用いて連続的に２時間かけて添加した（反応方法Ｉ）。添加後さらに40℃で１時間反応を行ない、１日静置しても分離等を起こさない、安定性に優れる（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子（５０：５０）分散水溶液（ａ−１）を得た。
得られた分散水溶液のｐＨは8.75であり、沈降物の生成はほとんど認められず、数週間室温にて静置しても分離、沈降等の変化を起こさずに安定であった。さらに、得られた微粒子分散液を2,000rpmで１０分間遠心処理を行ったが、分離、沈降等の変化は認められなかった。
【０１２０】
〔複合化実施例２〜３３〕
表３に記載した各種（メタ）アクリルアミド系重合体Ｂ−Ｐを用い、表３に示す条件で複合化実施例１と同様に反応を行い、微粒子分散水溶液ｂ−１〜ｐ−１を得た。
複合化比率、仕込量、反応条件、反応方法、反応結果は表３に記載した。
なお、方法Ｉ、IIにおいて、重合体水溶液は予めｐＨ10.0に調整後、リン酸または水酸化カルシウムと混合した。フィード液量は反応液全体の４０％量を標準とした。
また、複合化実施例は反応濃度（固形分）５％、反応温度４０℃を標準とたが、反応濃度を１０％に上げた例（複合化実施例１０、１１）、反応温度を２０−８０℃に設定した例（複合化実施例１３〜１６）においても、問題なく複合化できることを示した。
なお、重合体Ａ、Ｃ、Ｄ、Ｅ、Ｆは共重合モノマーにカルボキシル基を含まない重合体ではあるが、複合化反応過程でポリマー主成分であるアクリルアミド、あるいはＮ，Ｎ−ジメチルアクリルアミドのアミド結合がアルカリ（水酸化カルシウム）による加水分解反応を受けてカルボキシル基を生成しており（加水分解反応で生成するアンモニア、及びジメチルアミンを検出）、その結果として複合化が良好になっているのである。
【０１２１】
＜（メタ）アクリルアミド系重合体との複合化（２）＞
〔複合化実施例３４〜３８〕
カルボキシル基含有ポリアクリルアミド（ホープロン−３１５０Ｂ、三井化学社製）を用い、表４に示す条件で複合化実施例１と同様に反応を行い、微粒子分散水溶液ｑ−１〜ｑ−５を得た。
複合化比率、仕込量、反応条件、反応方法、反応結果は表４に記載した。
【０１２２】
＜ビニルピロリドン系重合体との複合化＞
〔複合化実施例３９〜４２〕
表２に記載したビニルピロリドン系重合体Ｒ〜Ｕを用い、表４に示す条件で複合化実施例１と同様に反応を行い、微粒子分散水溶液ｒ−１〜ｕ−１を得た。
複合化比率、仕込量、反応条件、反応方法、反応結果は表４に記載した。
【０１２３】
〔複合化比較例１〜５〕
重合体を添加しないブランク（比較例１）、および表２に記載した水溶性重合体Ｖ〜Ｙを用い、表４に示す条件で複合化実施例１と同様に反応を行ったが、何れも攪拌を止めて静置すると直ちに沈降分離した。
複合化比率、仕込量、反応条件、反応方法および反応結果は表４に記載した。
【０１２４】
複合化実施例３９〜４２と複合化比較例１〜５とを対比させると明らかなように、ビニルピロリドン系重合体の場合、カルボキシル基をもつ共重合体成分が安定な複合分散液をつくるために必要であることが判る。ポリマーの主成分であるＮ−ビニル−２−ピロリドンは本発明の複合化条件下ではアルカリによる加水分解反応を受けず、複合化反応過程においてもカルボキシル基を生成しない。その点で前記したアミド系のポリマーとは異なるため、比較例のようにカルボキシル基を含有しない共重合体を用いると安定な分散溶液とはならないのである。
【０１２５】
＜カルボキシル基変性ＰＶＡとの複合化例＞
〔複合化実施例４３〕
攪拌機、温度計を備えた丸底セパラブルフラスコに予め蒸留水で溶解しておいたカルボキシル基変性ポリビニルアルコール（ＰＶＡ ＫＭ−１１８；（株）クラレ社製、ケン化度 97.4モル％、重合度 1,800 ）水溶液（9.35％）127.01g 、蒸留水20.91gを入れ、10％水酸化ナトリウム1.62g を加えた後に、水酸化カルシウム0.461gを攪拌しながら加えて懸濁液とした。懸濁液の温度を40℃に調整し、攪拌速度200rpmで攪拌しながら、10.5％リン酸水溶液3.50g 、蒸留水96.50gを混合溶解した水溶液をミクロチューブポンプを用いて連続的に２時間かけて添加した。添加後さらに40℃で２時間反応を行ない、カルボキシル基変性ポリビニルアルコール／リン酸カルシウム微粒子（９５：５）分散水溶液（ｚ−１）を得た。得られた分散水溶液のｐＨは6.55であり、沈降物の生成はほとんど認められず、数週間静置しても分離、沈降等の変化を起こさずに安定であった。さらに、得られた微粒子分散液を2,000rpmで１０分間遠心処理を行ったが、分離、沈降等の変化は認められなかった。反応液の固形分濃度は5.2 ％であった。
【０１２６】
〔複合化実施例４４〜６６〕
カルボキシル基変性ポリビニルアルコール（Ｚ１〜Ｚ１３）を用い、表５に示す条件で複合化実施例４３と同様に反応を行った。
複合化比率、仕込量、反応条件、反応方法および反応結果は表５に記載した。
複合化に用いたカルボキシル基変性ポリビニルアルコールは、Ｚ１：ＫＭ−１１８（ケン化度 97.4モル％）、Ｚ２：ＫＭ−６１８（ケン化度 93.7モル％）、Ｚ３：ＫＬ−１１８（ケン化度 97.4モル％）（Ｚ３’は予め未ケン化相当量のＮａＯＨで加水分解処理）、Ｚ４：Ｋ−５１１２（ケン化度 95.1モル％）、 Ｚ５：ＳＫ−５１０２（ケン化度 97.6モル％）（以上クラレ社製）、Ｚ６：ＵＦＡ１７０（ケン化度 ＞96.5モル％）、Ｚ７：ＵＦＡ１７０Ｍ（ケン化度 92−95モル％）、Ｚ８：ＵＰＡ１７０（ケン化度 88−92モル％）（以上ユニチカ社製）、Ｚ９：Ｔ−３３０Ｈ（ケン化度 ＞99.0モル％）、Ｚ１０：Ｔ−３３０（ケン化度 95.0−98.0モル％）、Ｚ１１：Ｔ−３５０（ケン化度 93.0−95.0モル％）、Ｚ１２：Ｔ−２３０（ケン化度 95.0−98.0モル％）、Ｚ１３：Ｔ−２１５（ケン化度 95.0−98.0モル％）（以上日本合成化学社製）である。
【０１２７】
〔複合化比較例６〕
攪拌機、温度計を備えた丸底セパラブルフラスコに、予め蒸留水で溶解しておいた高純度ポリビニルアルコール（ＰＶＡ １０３Ｃ；（株）クラレ社製、ケン化度 98.6モル％、重合度300 ）水溶液（10.0％）62.50g、蒸留水82.89gを入れ、10％水酸化ナトリウム0.05g を加えた後に、水酸化カルシウム4.61g を攪拌しながら加えて懸濁液とした。懸濁液の温度を40℃に調整し、攪拌速度200rpmで攪拌しながら、10.5％リン酸水溶液34.97g、蒸留水65.03gを混合溶解した水溶液をミクロチューブポンプを用いて連続的に２時間かけて添加した。添加後さらに40℃で２時間反応を行ない、ポリビニルアルコール／リン酸カルシウム微粒子（５０：５０）分散水溶液（Ｚ１４−１）を得た。
得られた分散水溶液のｐＨは7.61であり、一夜静置すると反応液の約20％が透明な上澄液となって分離した（静置分散性４）。反応液の固形分濃度は5.0％であった。
【０１２８】
〔複合化比較例７〜１１〕
各種ポリビニルアルコールＺ１４−Ｚ１６を用い、表５に示す条件で複合化比較例６と同様に反応を行ったが、何れも攪拌を止めて静置すると沈降分離した。複合化比率、仕込量、反応条件、反応方法および反応結果は表５に記載した。
複合化に用いたポリビニルアルコールは、Ｚ１４：１０３Ｃ（高純度ポリビニルアルコール、ケン化度 98.6モル％）、Ｚ１５：２０５Ｃ（高純度ポリビニルアルコール、ケン化度 88.1モル％）、Ｚ１６：ＣＭ−３１８（カチオン性ポリビニルアルコール、ケン化度 96.4モル％）、Ｚ１７：２０５Ｓ（部分ケン化型ポリビニルアルコール、ケン化度 88.0モル％）（Ｚ１４’、１６’は予め未ケン化相当量のＮａＯＨで加水分解処理）（以上クラレ社製）である。
【０１２９】
複合化比較例６〜１１から明らかなように、分子内にカルボキシル基をもたないＰＶＡでは、安定な微粒子分散水溶液とはならない。複合化比較例７、１０では完全ケン化処理を行い、未ケン化部による影響をなくしたが、それでも複合化は不良であり、複合化に及ぼすカルボキシル基の効果は明らかである。
【０１３０】
〔複合化分散水溶液の安定性〕
（１）ｐＨ効果
複合化実施例１０で得られた分散水溶液（ｈ−３）に蒸留水を加えて希釈し、濃度を0.5wt％に調整した。この分散液約30mlに、攪拌しながら11.1wt％リン酸水溶液をマイクロシリンジで少量ずつ添加して、ｐＨを6.51、5.93、5.52、5.01に調整した。添加直後には何れも変化が認められなかったが、ｐＨ5.01に調整したものは一夜放置すると完全に二層分離した。その他のものは目視での変化は認められなかった。
また、0.5wt％希釈溶液に11.1wt％リン酸を継続して添加すると、ｐＨ4.5付近でリン酸を消費して、白濁分散水溶液が完全に透明化した。二相分離を起こすｐＨ領域は、重合体のカルボキシル基のｐＫa領域であり、ｐＨ低下に伴ってカルボン酸陰イオンが部分的または全体にわたってイオン性を失うことが、複合化分散液の安定性に影響を及ぼしているものと考えられる。さらにｐＨを下げると、ヒドロキシアパタイトの溶解に伴なって、複合体は消失するため透明化するのである。
【０１３１】
（２）無機塩添加効果
複合化実施例１０で得られた分散水溶液を（１）と同様に、濃度を0.5wt％に調整した。この際に、塩濃度が0.05〜2.0mol/ｌになるようにＮａＣｌ、Ｎａ₂ＳＯ₄を添加して分散液の安定性を評価した。
この濃度範囲ではＮａＣｌ添加による変化は認められなかったが、Ｎａ₂ＳＯ₄添加系は0.25mol/l以上の濃度で完全に２層に分離し、0.05mol/l濃度では１ケ月経た後も変化はなかった。
以上のｐＨおよび塩添加効果は、分散安定化にはイオン的な作用が重要な役割を果たしていることを示しており、それはカルボン酸陰イオンによる作用であることが強く示唆された。
【０１３２】
〔電子顕微鏡観察／分散液〕
・ポリ（メタ）アクリルアミド（ＰＡＭ）系複合体
複合化実施例９で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−２）を希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真を図１(a)に示した。
図１(a)を見ると明らかなように、リン酸カルシウム微粒子は細長い楕円状粒子となっており、これらの１次粒子が凝集することなくコロジオン膜上に均一に分散している。図１から求めた長軸方向の粒径分布を図３に示した。
【０１３３】
・カルボキシル基変性ＰＶＡ系複合体
複合化実施例５０で得られたカルボキシル基変性ポリビニルアルコール／リン酸カルシウム微粒子分散水溶液（ｚ１−８）を希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真を図１(b)に示した。
図１(b)も図１(a)とほぼ同様にリン酸カルシウム微粒子は細長い楕円状粒子となっており、これらの１次粒子が凝集することなくコロジオン膜上に均一に分散している。
【０１３４】
・ブランク
複合化比較例１で得られたブランクのリン酸カルシウム分散水溶液（ｂｌａｎｋ）は、沈降・分離しているため、良く攪拌してサンプリングを行った後希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真を図２に示した。
図２を見ると、細長い針状の結晶が多数凝集している構造となっており、安定な分散水溶液である図１(a)、(b)とは著しく異なっていることが判る。
【０１３５】
〔フィルム作成〕
〔フィルム作成例１〕
複合化実施例１〜６６で得られた安定な分散水溶液（ａ−１〜ｚ１３−１）を直径90mmのポリメチルペンテン樹脂製のシャーレに入れ、水平台上にのせて乾燥窒素を流すことによって、透明性に優れるカルボキシル基含有重合体／リン酸カルシウム複合フィルムを製造した。全ての試料が透明なフィルムとなった。さらに１１０℃の送風乾燥機で２時間乾燥処理を行ったフィルムについても透明性に変化が認められなかった。
シャーレに入れる液量を調節することにより、種々の厚みを持つフイルムを作成した。とくに複合化実施例４３〜６６で得られたＰＶＡ系複合分散水溶液（ｚ１−１〜ｚ１３−１）から作成されるフイルムは強靭かつ柔軟なフィルムであり、ハサミによる裁断加工性を備えていた。さらに、これらの分散液に、固形分重量に対して１０％、２０％、３０％のグリセリンを可塑剤として添加することで、５０％リン酸カルシウムを含有する複合体において完全に乾燥したフイルムでも柔軟性に富み、折り曲げても割れないようになった。
複合化比較例２〜１０で得られた分散水溶液（ｖ−１〜ｙ−１、ｚ１４−１〜ｚ１６−２）は沈降・分離しているため、良く攪拌した後に直径90mmのポリメチルペンテン樹脂製のシャーレに入れ、水平台上にのせて乾燥窒素を流すことによって、カルボキシル基を含有しないポリビニルアルコール／リン酸カルシウム複合フィルムを製造しようとしたが、透明なポリマーフィルムと白色固体に完全に分離し、均一な複合体フィルムにはならなかった。
【０１３６】
〔フイルム作成例２〕
必要に応じて濾布または金属メッシュで濾過処理を行った複合化実施例１〜６６で得られた安定な分散水溶液（ａ−１〜ｚ１３−１）をポリエチレンテレフタレート（ＰＥＴ）フイルムの上にバーコーターで塗布し、フイルムを固定して風乾することで透明性に優れるカルボキシル基含有重合体／リン酸カルシウム複合体を表面層にもつフイルムを作成した。
【０１３７】
〔フイルム作成例３〕
必要に応じて、濾布または金属メッシュで濾過処理を行った複合化実施例１〜６６で得られた安定な分散水溶液（ａ−１〜ｚ１３−１）をガラス上に流し塗り、水平台上にのせて乾燥窒素を流すことによって、透明性に優れるカルボキシル基含有重合体／リン酸カルシウム複合フイルムを表面層にもつガラス板を作成した。
【０１３８】
〔フイルム引張り強度測定〕
・カルボキシル基変性ＰＶＡ系複合体
複合化実施例５１で得られた分散水溶液（ｚ１−９）（重合体：リン酸カルシウム＝５０：５０複合体）からフイルム作成例１で得られた、平均膜厚64μmのフイルムと、複合化に使用した原料ＰＶＡ（Ｚ１：ＫＭ−１１８）水溶液から同様の方法で製膜化した平均膜厚75μmのフイルムを用い、23±2℃、50±5％ＲＨの条件下で１週間調湿した各試料について、ＪＩＳ Ｋ７１１３ ２(1/2)号形の試験片で50.0mm/minの速度で引張り試験を行った。
ＰＶＡ単独系での引張強度（破断）65.3ＭＰaに対し、複合フイルムの引張強度は116.8ＭＰaと、約80％近く強度の向上が認められた。
【０１３９】
〔超微小硬度測定〕
・カルボキシル基変性ＰＶＡ系複合体
ダイナミック超微小硬度計ＤＵＨ−２０１型（島津製作所製）を使用して、複合化実施例５１の分散水溶液（ｚ１−９）（重合体：リン酸カルシウム＝５０：５０複合体）からフイルム作成例１で得られたフイルムと、複合化に使用した原料ＰＶＡ（Ｚ１：ＫＭ−１１８）単独のフイルムについて測定を行った。各々のフイルム厚は引張り試験で使用したフイルムと同程度のものを使用し、23±2℃、50±5％ＲＨの条件下で１週間調湿した試料について、No-2モードにて、試験荷重9.8mＮ、保持時間５秒、負荷速度1.428mＮ/sec、変位フルスケール10μmの条件で試験を行った。
9.8mＮ５秒保持時および除荷後の押込み深さ（Ｄ1、Ｄ2(μm)）は10点計測した平均値を取ると、ＰＶＡ単独系でそれぞれ1.42、1.04に対し、複合系では1.06、0.77であった。この数値より計算されるダイナミック硬さ（ＤＨＴ115-1、ＤＨＴ115-2）は、ＰＶＡ単独系でそれぞれ19.0、35.4に対し、複合系では33.8、65.2であり、複合化により表面硬度が増加することが判った。
なお、ダイナミック硬さは以下の計算式より算出される。三角錐圧子(115°)を用いた場合、α＝3.8584である。
ダイナミック硬さ＝｛9.8(mＮ)／Ｄ2｝×α
【０１４０】
〔ガス透過性〕
複合化実施例５１の分散水溶液（ｚ１−９）（重合体：リン酸カルシウム＝５０：５０複合体）からフイルム作成例１で得られたフイルムと、複合化に使用した原料ＰＶＡ（Ｚ１：ＫＭ−１１８）単独のフイルムについてヘリウムガスのフイルム透過率測定を行った。透過率測定は、４重極型質量分析計を検出器とした特開平６−２４１９７８に開示されているフイルム用ガス透過率測定装置を用いた。ＰＶＣ単独フイルムの厚さは82μｍで、ヘリウムガスの透過量10.7cc/m²・day（透過係数：13.3*10-¹³cc*cm/cm²・sec・cmＨg）に対して、複合化フイルムの厚さは55μｍで、透過量7.5cc/m²・day（透過係数：6.3*10-¹³cc*cm/cm²・sec・cmＨg）であった。複合化により透過係数は50％以下になり、ガスバリア性が大幅に向上することが確認された。
【０１４１】
〔ＦＴ−ＩＲ測定〕
・ＰＡＭ系複合体
複合化実施例１２で製造した分散水溶液（ｈ−５）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを図４(a)に示す。
（メタ）アクリルアミド系重合体に由来するピークとヒドロキシアパタイトに由来するピークの両方が観測された。
また、このフィルムを電気炉中で８００℃で３時間熱処理を行うと白色固体が残り、その重量は熱処理前の５０％であった。その白色固体のＩＲスペクトルを図４(b)に示す。熱処理によりポリマー成分は焼失し、結晶化が進んだヒドロキシアパタイトが定量的に残ったことが確認された。
【０１４２】
・カルボキシル基変性ＰＶＡ系複合体
複合化実施例４９で製造した分散水溶液（ｚ１−７）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを図５(a)に示す。
カルボキシル基変性ポリビニルアルコールに由来するピークとヒドロキシアパタイトに由来するピークの両方が観測された。
また、このフィルムを電気炉中で８００℃で９時間熱処理を行うと白色固体が残り、その重量は熱処理前の５０％であった。その白色固体をＫＢｒ錠剤法により測定したＦＴ−ＩＲスペクトルを図５(b)に示す。熱処理によりポリマー成分は焼失し、結晶化が進んだヒドロキシアパタイトが定量的に残ったことが確認された。
【０１４３】
・ポリビニルピロリドン系複合体
複合化実施例４２で製造した分散水溶液（ｕ−１）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを図６に示す。
ビニルピロリドン系重合体に由来するピークとヒドロキシアパタイトに由来するピークの両方が観測された。
【０１４４】
〔Ｘ線回折分析（ＸＲＤ）〕
・ＰＡＭ系複合体
複合化実施例１２で製造した分散水溶液（ｈ−５）を凍結乾燥により粉末とした試料のＸＲＤスペクトルを図７(a)に、及び同一の分散水溶液をフイルム作成例３で示した方法によりガラス基板上にキャストしてフィルム化した試料のＸＲＤスペクトルを図７(b)に示す。なお、（ｈ，ｋ，０）面に対応するピークに＊を印した。
粉末のスペクトルパターンはヒドロキシアパタイトと一致したが、フィルムのスペクトルは（ｈ，ｋ，０）面のピークは観測されるものの、それ以外のピークは強度が大きく低下するか消失していることから、フィルム中のヒドロキシアパタイト粒子はｃ軸がガラス面に対して平行に配向しているものと推測される。
【０１４５】
・カルボキシル基変性ＰＶＡ系複合体
複合化製造例４９で製造した分散水溶液（ｚ１−７）を凍結乾燥により粉末とした試料のＸＲＤスペクトルのスペクトルパターンはヒドロキシアパタイトとほぼ一致した（図８(ａ)）。ヒドロキシアパタイトの（ｈ，ｋ，０）面のピークは観測されるものの、それ以外のピークは強度が大きく低下するか消失していた。同一の分散水溶液をガラス基板上にキャストしてフィルム化した試料のＸＲＤスペクトルを図８(a)に示した。（メタ）アクリルアミド系重合体との複合体と同様に、フィルム中のヒドロキシアパタイト粒子はｃ軸がガラス面に対して平行に配向しているものと推測された。
【０１４６】
〔電子顕微鏡観察／フイルム〕
・ＰＡＭ系複合体
複合化実施例１２で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−５）から、キャスト法により製造した複合フィルム（フィルム作成例１）を、超薄切片法によりフィルムの平面方向と断面方向から透過型電子顕微鏡（ＴＥＭ）により観察した。平面方向の結果を図９(a)に、断面方向の結果を図９(b)に示す。
平面方向(a)には長軸が７０−２００ｎｍ、短軸が２５−５０ｎｍ程度の細長い楕円状粒子が観察された。一方、断面方向(b)にはその細長い粒子を輪切りにしたような像が多数観察され、一部には中空構造を示すものも観察された。平面方向に長軸が配向していることを示す電子顕微鏡像は、ＸＲＤの結果と良く一致する。ＵＴＷ（Ultra Thin Window）型ＥＤＳ検出器（Energy Dispersive Spectroscopy：エネルギー分散型分光法）による粒子の局所元素分析の結果、Ｃａ／Ｐの元素比は３点の平均で１．４３の値を示した。ヒドロキシアパタイトのＣａ／Ｐ比は１．６７であることから、フィルム中のリン酸カルシウム粒子はカルシウム欠損型のヒドロキシアパタイトであることが、ＸＲＤとＩＲおよびＴＥＭの結果から示された。
【０１４７】
〔フイルム光透過率測定〕
・ＰＡＭ系複合体
安定性に優れる分散液ａ−１〜ｕ−１から、フイルム作成例１の方法でつくられた複合フィルム（フィルムの平均膜厚は230μｍ−270μｍの範囲にあった）の光透過率の波長依存性は似通ったパターンを示し、何れも７００ｎｍでの透過率は５０％を越え、高い透明性を示した。それらの中から、重合体／リン酸カルシウム複合フィルムと重合体単独フィルムの比較を図１０に示した。
図１０から明らかなように、複合フィルムのほうが重合体単独フィルムに比べて透明性が良好であった。
また、複合化温度が透明性に及ぼす効果を図１１に示した〔分散水溶液ｈ−７から作成したフイルム（複合化温度：４０℃）、分散水溶液ｈ−８から作成したフイルム（複合化温度６０℃）、分散水溶液ｈ−９から作成したフイルム（複合化温度８０℃）〕。図１１からは複合化温度によりフィルムの透明性が変化することが判った。
【０１４８】
フィルム中に含まれる水分量の影響を図１２に示した。分散水溶液ｈ−７から作成した複合フイルムを水中に浸漬し、その後風乾して含水量を変化させた。含水量がフイルム重量に対してそれぞれ３％、５０％、６５％、８５％、１２２％のフイルムについて測定した。なお、フイルムを１２０℃で４時間乾燥したものを含水量０％とした。図１２からはフィルム中の水分量により透明性が変化することが判り、この変化は可逆的であった。この現象は特に紫外光領域での変化幅が大きく、ＵＶ遮光性の化粧品へ利用できることを示す。
【０１４９】
・カルボキシル基変性ＰＶＡ系複合体
安定性に優れる微粒子分散水溶液（ｚ１−１〜ｚ１３−１）から、フイルム作成例１の方法でつくられた複合フィルムの光透過率の波長依存性は、似通ったパターンを示し、何れも７００ｎｍでの透過率は５０％を越え、高い透明性を示した。測定に用いたフィルムは、平均膜厚が90μｍ〜150 μｍの範囲にあり、図１３に示す分散水溶液ｚ１−３（９０：１０複合体）、ｚ１−５（７０：３０複合体）からフイルム作成例１でつくられたフィルムはそれぞれ約120 、140 μｍ、分散水溶液ｚ１−６（６０：４０複合体）、ｚ１−７（５０：５０複合体）から同様につくられたフイルムは約90μｍであった。
【０１５０】
〔紙への塗工試験〕
以下の塗工実施例および塗工比較例には、被塗工原紙として中質紙（坪量58g/m²）を用いた。表面強度は、ＲＩ−３型（明製作所社製）を用いてＲＩピックを（１０点法の相対評価で点数が高いほど表面強度が高い）、Ｚ軸強度はインターナルボンドテスター（熊谷理機工業社製）を用いて測定した。
【０１５１】
〔塗工実施例１〜５〕
複合化実施例３４〜３８で得られた微粒子分散水溶液（ｑ−１〜ｑ−５）に被塗工原紙を１秒間浸漬し、２本のロールで搾った後に吸収された液量を秤量して塗工量を求めた。塗工量は（メタ）アクリルアミド系重合体とリン酸カルシウムの不揮発分で 1.0および1.8g/m²となるように予め塗工液の濃度を調製した（分散水溶液濃度：2.0〜3.5wt％）。また、塗工液のｐＨは7.8〜8.2に調整した。塗工後直ちに表面温度を１１０℃に設定したドラムドライヤーで９０秒間乾燥し、恒温恒湿室（２０℃、６５％ＲＨ）中で２４時間調湿後の紙力強度を測定した。結果は表６に示した。
【０１５２】
〔塗工比較例１〕
塗工液を（メタ）アクリルアミド系重合体（ホープロン３１５０Ｂ；三井化学社製）の単独水溶液に変えた以外には塗工実施例１〜５と同様の操作を行って塗工紙を作り、紙力強度を測定した。
結果は表６に示した。
【０１５３】
表６の結果から、分散水溶液の紙力向上能は従来の（メタ）アクリルアミド重合体に比べて極めて優れていることが明らかである。特に、（メタ）アクリルアミド重合体／リン酸カルシウム比が９５／５の分散液では、ブランクである被塗工原紙からのＺ軸強度向上率は、塗工比較例１に対して２０〜３５％もアップしており、重合体単独で用いる場合に比べて非常に良好な結果を与える。これらの結果は、重合体単独で到達できる紙力強度の限界を、リン酸カルシウム微粒子を分散させて重合体と複合化することにより更に引き上げることが可能であることを意味するものである。
【０１５４】
〔インクジェット（ＩＪ）用塗工試験〕
以下の塗工実施例および塗工比較例には、被塗工原紙として上質紙（ＯＫ−プリンス、坪量104.7g/m²：王子製紙（株）社製）を用いた。
【０１５５】
〔ＩＪ塗工実施例１〕
実施例１１で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−４）を10％に調整後、被塗工原紙上に塗工量5.0g/m²になるようにワイヤーバーにて塗工した。塗工後、120℃で90秒乾燥し、インクジェット記録用シートを得た。
【０１５６】
〔ＩＪ塗工比較例１〕
微粉末ヒドロキシアパタイト（ＨＣＡ−３０００：三井化学（株）社製）１０部と水９０部を、ホモジナイザー（日本精機製作所製）を用いて3000rpm、３分間攪拌して得られた10％分散液と10％に調整した重合体製造例で得られた重合体Ａ水溶液を１：１で混合し、塗工液とした。得られた塗工液を被塗工原紙上に乾燥塗工量が5.0g/m²になるようにワイヤーバーにて塗工した後、120℃で90秒乾燥し、インクジェット記録用シートを得た。
【０１５７】
〔ＩＪ塗工比較例２〕
微粉末シリカ（ミズカシルＰ−７８Ａ：水澤化学工業（株）社製）１０部と水９０部をホモジナイザーを用いて3000rpm、３分間攪拌して得られた10％分散液とポリビニルアルコール（ＰＶＡ−１１７Ｓ：（株）クラレ社製）の10％水溶液を１：１で混合し、塗工液とした。得られた塗工液を被塗工原紙上に塗工量5.0g/m²になるようにワイヤーバーにて塗工した後、120℃で90秒乾燥し、インクジェット記録用シートを得た。
【０１５８】
〔ＩＪ塗工比較例３〕
ポリビニルアルコールをポリビニルピロリドン（Ｋ−９０：ＩＳＰ社製）に変えた以外はＩＪ塗工比較例２と同様の操作を行い、インクジェット記録用シートを得た。
【０１５９】
〔ＩＪ塗工比較例４〕
微粉末シリカを微粉末アルミナ（カタロイドＡＰ−３：触媒化成（株）社製）に変えた以外はＩＪ塗工比較例２と同様の操作を行い、インクジェット記録用シートを得た。
【０１６０】
〔ＩＪ塗工比較例５〕
ポリビニルアルコールをポリビニルピロリドン（Ｋ−９０：ＩＳＰ社製）に、微粉末シリカを微粉末アルミナ（カタロイドＡＰ−３：触媒化成（株）社製）に変えた以外はＩＪ塗工比較例２と同様の操作を行い、インクジェット記録用シートを得た。
【０１６１】
上記の方法で作成したインクジェット記録用シートについて、印刷適性および耐黄変性について以下のように調べた。
印刷適性については、市販のインクジェットプリンター（ＰＭ−２０００Ｃ：セイコーエプソン（株）社製）で印刷し、印字濃度、ドット形状（真円性）について評価した。
印字濃度はマクベス濃度計（ＲＤ−９１８）を用いてブラック、シアン、マゼンダ、イエローのベタ部分を測定し、印字濃度がかなり高く優秀な「◎」、印字濃度が高い「○」、普通の「△」、印字濃度が低い「×」の４段階評価した。
ドット形状（真円性）はルーペで拡大観察し、目視により、真円性の高い優秀な「◎」、良好な「○」、やや滲みを生じる「△」、真円性のない「×」の４段階評価した。
評価結果を表７に示す。
【０１６２】
耐黄変性については、以下のように評価した。
作成したインクジェット記録用シートに粘着テープ（セロテープ：ニチバン（株）製）を貼付し、20℃で４週間または40℃で２週間放置した。分光色彩計（カラーガイド：ビック−ガードナー社製）にてＬ、ａ、ｂ値を測定して全色差△Ｅ（△Ｅ＝｛（△Ｌ）²＋（△ａ）²＋（△ｂ）²｝^1/2）を算出し、△Ｅの値が小さくほとんど黄変しない場合を「◎」、黄変が進み、△Ｅの値が大きくなるにつれて
「○」、「△」、「×」とする４段階評価をした。
【０１６３】
表７に示す通り、（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液を塗工したシートは粘着テープを貼付しても黄変せず、耐黄変性に優れていることがわかる。さらに、印刷適性についてもトータルバランスに優れていることから優れたインクジェット記録用薬品となっていることがわかる。
【０１６４】
【表１】

【０１６５】
【表２】

【０１６６】
【表３】

【０１６７】
【表４】

【０１６８】
【表５】

【０１６９】
【表６】

【０１７０】
【表７】

【０１７１】
【発明の効果】
本発明により、種々の用途に利用可能な分散安定性に優れるカルボキシル基を含む水溶性または水分散性の合成高分子化合物／無機微粒子分散水溶液、およびカルボキシル基を含む水溶性または水分散性の合成高分子化合物／無機微粒子複合体を提供することができる。
本発明のカルボキシル基を含む水溶性または水分散性の合成高分子化合物／無機微粒子からなる製紙用薬品は、紙力増強剤として従来より用いられている（メタ）アクリルアミド系重合体に比べ、さらに高い紙力増強能を有する製紙用薬品および該製紙用薬品を使用して得られる紙を提供することができる。
さらに、本発明のカルボキシル基を含む水溶性または水分散性の合成高分子化合物／無機微粒子からなるインクジェット記録用薬品は、従来よりインクジェット記録用薬品として用いられている微粉末シリカや微粉末アルミナに比べて塗工層の耐黄変性に優れており、耐黄変性に優れたインクジェット記録用シートを提供することができる。
【図面の簡単な説明】
【図１】（ａ）複合化実施例９で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−２）を希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真。
（ｂ）複合化実施例５０で製造したカルボキシル基変性ポリビニルアルコール／リン酸カルシウム微粒子分散水溶液（ｚ１−８）を希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真。
【図２】 複合化比較例１で製造したリン酸カルシウム微粒子分散液を希釈し、コロジオン膜張銅メッシュ上で乾燥して撮影した透過型電子顕微鏡写真
【図３】図１(a)から求めた長軸方向の粒径分布図
【図４】 (a)複合化実施例１２で製造したＰＡＭ系分散水溶液（ｈ−５）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを示す図
(b)このフィルムを電気炉中で８００℃、３時間熱処理を行って得られた白色固体のＫＢｒ錠剤法によるＦＴ−ＩＲスペクトルを示す図
【図５】 (a)複合化実施例４９で製造したカルボキシル基変性ＰＶＡ系分散水溶液（ｚ１−７）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを示す図
(b)このフィルムを電気炉中で８００℃、９時間熱処理を行って得られた白色固体のＫＢｒ錠剤法によるＦＴ−ＩＲスペクトルを示す図
【図６】複合化実施例４２で製造したポリビニルピロリドン系分散水溶液（ｕ−１）をＫＲＳ−５の窓板にキャストして薄膜とした試料のＦＴ−ＩＲスペクトルを示す図
【図７】 (a)複合化実施例１２で製造したＰＡＭ系分散水溶液（ｈ−５）を凍結乾燥により粉末とした試料のＸＲＤスペクトルを示す図
(b)複合化実施例１２で製造したＰＡＭ系分散水溶液をガラス基板上にキャストしてフイルム化した試料のＸＲＤスペクトルを示す図
〔（ｈ，ｋ，０）面に対応するピークに＊を印した〕
【図８】 (a)複合化実施例４９で製造したカルボキシル基変性ＰＶＡ系分散水溶液（ｚ１−７）を凍結乾燥により粉末とした試料のＸＲＤスペクトルを示す図
(b)複合化実施例４９で製造したカルボキシル基変性ＰＶＡ系分散水溶液をガラス基板上にキャストしてフイルム化した試料のＸＲＤスペクトルを示す図
【図９】複合化実施例１２で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−５）からフイルム作成例１によりつくられたフィルムを超薄切片法によりフィルムの平面方向(a)と断面方向(b)を撮影した透過型電子顕微鏡写真
【図１０】複合化実施例１４で得られた（メタ）アクリルアミド系重合体／リン酸カルシウム微粒子分散水溶液（ｈ−７）からフイルム作成例１によりつくられたフイルムと、（メタ）アクリルアミド系重合体Ｈ▲２▼の単独フイルムの光透過率の波長依存性を示す図
【図１１】複合化温度の異なる（メタ）アクリルアミド系重合体／リン酸カルシウム複合フイルムの光透過率の波長依存性を示す図
〔分散水溶液ｈ−７（複合化温度：４０℃）、分散水溶液ｈ−８（複合化温度：６０℃）、分散水溶液ｈ−９（複合化温度：８０℃）からつくられたフイルム〕
【図１２】含水率が異なる（メタ）アクリルアミド系重合体／リン酸カルシウム複合フイルム（分散水溶液ｈ−７から作製）の光透過率の波長依存性を示す図
（含水量がフイルム重量に対してそれぞれ３％、５０％、６５％、８５％、１２２％のフイルムについて測定した。なお、フイルムを１２０℃で４時間乾燥したものを含水量０％とした。）
【図１３】複合化比率の異なるカルボキシル基変性ＰＶＡ／リン酸カルシウム複合フイルム（分散水溶液ｚ１−３、ｚ１−５、ｚ１−６、ｚ１−７から得られたフイルム）の光透過率の波長依存性を示す図[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic polymer / inorganic fine particle-dispersed aqueous solution and a composite excellent in dispersion stability, and a production method and use thereof.
[0002]
[Prior art]
Materials such as organic, inorganic, and metal can be combined to create materials that cannot be realized with a single material alone, and it has become a natural method in modern material development. For example, a fiber reinforced plastic material (FRP) in which glass fibers and a polymer are combined has a strength that cannot be achieved by a polymer alone. On the other hand, when this material is viewed from the glass fiber side, it can be said that a glass fiber that is fragile by itself and poor in workability becomes a material having moldability by being combined with a polymer. In this way, by making use of the characteristics of each material or making up for defects by combining, functions and performances that cannot be achieved with a single material can be realized. In the conventional composite material, the size of the dissimilar material (dispersed phase) in the matrix (dispersion medium) is on the order of micrometer or more, and the effect expected from the composite at that size has been brought about.
[0003]
Combined with advances in technology for analyzing microscopic areas such as scanning probe microscopes (SPM), this is achieved with conventional composite materials by reducing the size of the dispersed phase of composite materials to the nanometer order. A lot of reports that it is possible to make materials with high functions and multi-functions that could not be made or materials with new functions are attracting attention.
[0004]
An example of a material that combines organic and inorganic materials on the order of nanometers (hereinafter referred to as nanocomposite) is a nanocomposite that combines a layered clay mineral such as clay or synthetic layered silicate with a polymer such as nylon. And nanocomposites of silica and polymer using a sol-gel method are known. The former nanocomposite is composed of (1) a technique in which an organic monomer is inserted between layers of a layered compound, (2) an in-situ polymerization method in which polymer polymerization and filler generation / dispersion are performed simultaneously, (3) A method of kneading and dispersing in the presence of an organic cation has been studied. Since these basically utilize the cleaving phenomenon of the filler accompanying the intercalation of organic matter, inorganic materials are limited to layered clay minerals that can be dispersed in a nanometer order structure. The latter nanocomposite can be nanocomposited with an organic substance by synthesizing an inorganic substance at a low temperature by a sol-gel method. While there is a merit that a purified inorganic raw material can be used, the raw material is expensive, and there is a drawback that the volume shrinks with the reaction.
[0005]
Nanocomposites of organic polymers and inorganic substances can be obtained by mechanically pulverizing inorganic substances to the nanometer order, and then kneading them with organic polymers to form organic-inorganic nanocomposites. Although it has been devised, it is generally considered difficult to pulverize inorganic substances to the nanometer order, and even when pulverized, organic polymers that are different materials can be reduced to the nanometer order while suppressing reagglomeration. It is not easy to mix evenly.
[0006]
The present inventors have developed calcium phosphates which are not biologically toxic and have high affinity with organic substances such as hydroxyapatite (hereinafter abbreviated as HAp) and tricalcium phosphate (hereinafter abbreviated as TCP). We focused on the fact that it could be a very useful material if used as a constituent material of nanocomposites. HAp is an inorganic component constituting the hard tissue of vertebrates, and its practical application has been studied as a substitute for hard tissue such as artificial bone, artificial tooth root, and artificial joint. The HAp sintered body itself is a brittle material that is strong against compression but weak against tension, and has a drawback of poor moldability. As a measure to improve this defect, the stability of the molding process is improved by kneading with lactic acid-based polyester, and the organic-inorganic composite has a good balance in flexibility, strength, elastic modulus, reproducibility, and molding processability. Japanese Patent Application Laid-Open No. 10-229 discloses a technique for obtaining the above. This technology was devised based on the idea of providing a material closer to the living body in consideration of the fact that HAp exists in a complex with collagen, which is a biopolymer, in vivo. In this method, a calcium phosphate compound such as HAp or TCP is synthesized by a wet method, and the resulting precipitate is fired and ground, and then kneaded with a polymer in a mixer to obtain a composite. The calcium phosphate particles used here have a size of 5 mm or less, and the organic polymer is limited to lactic acid-based polyester. This material realizes osteoinductive ability or conduction ability and biocompatibility taking advantage of the characteristics of each material, and is not a material uniformly dispersed in the nanometer order.
[0007]
On the other hand, Japanese Patent Application Laid-Open No. 7-101708 discloses a complex that approximates a bone or tooth of a living body, which is made of HAp powder having a crystal grain size of 0.5 μm (500 nm) or less and an organic substance such as collagen. In this technique, a high Young's modulus is obtained by applying a pressure of 200 MPa to a hydrous material obtained by filtering and drying a precipitate formed by adding a mixed solution of collagen and phosphoric acid while stirring a calcium hydroxide suspension vigorously. Has obtained a complex. It has been clarified by Tanaka et al. That this HAp-collagen complex is a nanocomposite in which HAp particles (several nm) are c-axis oriented along collagen fibers (30 nm) [BIO INDUSTRY, Vol. 13 (N0.8), 28 (1996)]. However, for the purpose of producing materials close to living bones, it is necessary to establish synthetic methods that can freely control the strength close to living bones, and to establish methods that reduce the antigenicity of collagen. Issues are listed. Moreover, this material is not a highly transparent material characteristic of nanocomposites because it has an oriented structure.
[0008]
Many inorganic substances that can be synthesized by the liquid phase method such as calcium phosphate and calcium carbonate tend to be low crystalline and fine crystals, and usually form a gel-like precipitate. Usually, this precipitate is filtered, dried, sintered and then pulverized, but it is difficult to pulverize to primary particles, and it is also possible to disperse and knead the nano-order particles in the polymer. It is not easy, and there has been no practical method for producing a composite in which inorganic substances such as calcium phosphate synthesized by a liquid phase method are uniformly dispersed on the nanometer order.
[0009]
The paper industry is an industry that consumes a large amount of forest resources as raw materials and requires enormous energy in pulp production and papermaking processes. However, as environmental problems at the global level have become more serious in recent years, Efforts are being made to reduce the load on the plant as much as possible. In particular, the reuse of used paper as a resource is becoming increasingly important, and it is said that recycling is proceeding to a level close to its limit, excluding non-recoverable paper such as sanitary paper and books. . However, since waste paper is a raw material shortened by cutting and abrasion, etc., if the use ratio increases, the strength of the paper is reduced. Such a decrease in paper strength can be achieved by adding or coating starches such as oxidized starch and cationized starch, and water-soluble polymer compounds represented by polyvinyl alcohol (PVA) and (meth) acrylamide polymers. It has been compensated by crafting. On the other hand, from the viewpoint of resource saving, the above water-soluble property is used to compensate for the decrease in paper strength even when various additives such as inorganic pigments are incorporated into paper for the purpose of reducing the amount of pulp used. A paper strength enhancer made of a polymer compound is used.
[0010]
Among these paper strength enhancers, (meth) acrylamide polymers are known as high-performance chemicals that have a great effect when used in a very small amount. However, environmental issues are now an important issue that must be considered on a global scale, and there is a growing demand for high-performance chemicals in response to issues of deterioration of raw materials and reduction of pulp usage. .
[0011]
As methods for imparting high paper strength enhancing ability to (meth) acrylamide polymers, methods of copolymerizing with functional monomers, methods of introducing functional groups by post-modification, or methods of introducing a crosslinked structure have been studied. It has been. However, there is a limit to the performance that can be achieved only by the conventional method of modifying a polymer, and higher chemical performance is required in the future, and the emergence of papermaking chemicals based on a new concept is desired.
Inkjet printing has advantages such as low noise and quietness, high-speed printing, low printing cost, easy colorization, clear recording, and large-format printing. Widely used because it has. The ink jet recording method is a recording method in which ink droplets are ejected from fine nozzles by various operating methods and adhered to a recording sheet such as paper to obtain information as characters or images. As a sheet used in the ink jet recording method, ink droplets adhering to the sheet surface are quickly absorbed into the sheet by the principle of the method, ink spreading and bleeding on the surface are suppressed, color development In order to increase the density, characteristics such as ink staying in the vicinity of the sheet surface as much as possible are required.
[0012]
Conventionally, as a method for imparting these characteristics to an inkjet recording sheet, proposals have been made to provide an ink-absorbing coating layer on the sheet surface. For example, a coating layer composed mainly of a silica or alumina powder with high ink absorbability and a binder of a water-soluble polymer such as polyvinyl alcohol, and further mixed with various additives to improve ink fixability and water resistance. Has been proposed.
[0013]
As described above, the inkjet recording sheet having a coating layer using silica powder or alumina powder as the inorganic filler is greatly improved in terms of ink absorbability and the like, and it is possible to obtain a high-quality image. As a result, there arises a drawback regarding light resistance that the coating layer turns yellow. In recent years, due to remarkable progress of inkjet printers, full-color and high-quality images can be easily obtained, and the recording sheet needs to have high whiteness. The above-mentioned drawbacks related to light resistance become a serious problem. Furthermore, when an adhesive tape is applied to the recording sheet having the coating layer, there is a problem that yellowing occurs remarkably from the portion where the adhesive tape is applied. When an adhesive tape is affixed to the recording sheet for fixing or the like, there is a drawback that the appearance is remarkably impaired due to yellowing.
[0014]
In the process of compounding calcium phosphate containing HAp and other inorganic substances with a polymer, the present inventors do not cause precipitation, and if a material that can be formed into a molded body without applying high pressure can be developed, In addition to biomaterials, we thought it would be a useful material in many fields such as papermaking chemicals. However, there are some inorganic substances that cannot be applied to the above-described intercalation method or sol-gel method for nanocompositing with a polymer. Accordingly, the present inventors have focused on the fact that some inorganic substances can be synthesized in an aqueous medium by a liquid phase method other than the sol-gel method, and those inorganic substances and water-soluble or water-dispersible substances can be synthesized. It came to the idea that nanocomposite with a polymer might be possible.
[0015]
[Problems to be solved by the invention]
The object of the present invention is excellent in molding processability by stably dispersing inorganic fine particles of nanometer order with water-soluble or water-dispersible polymer compounds without causing aggregation / separation, which was difficult with conventional methods. Another object of the present invention is to provide an organic polymer / inorganic fine particle-dispersed aqueous solution that can be used for various purposes by producing a transparent film and its use.
[0016]
[Means for Solving the Problems]
The present inventors have prepared a water-soluble or water-dispersible synthetic polymer compound containing a carboxyl group, a poorly water-soluble inorganic fine particle having a particle size of 500 nm or less, particularly a Group 2 element compound of a periodic table, an organic acid, an inorganic acid, and salts thereof. The present inventors have found that a composite material combined with hardly water-soluble inorganic fine particles having a particle diameter of 500 nm or less, obtained by reacting one or more compounds selected from the above, is a material that meets the above-mentioned purpose, and has led to the present invention.
[0017]
That is, the present invention
(1) A water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group and a poorly water-soluble inorganic fine particle (B) having a particle size of 500 nm or less, (A): (B) = 10: 90- An organic polymer / inorganic fine particle dispersion aqueous solution excellent in dispersion stability, characterized by containing at 99.99: 0.01 (weight ratio),
(2) The organic polymer / inorganic fine particles having excellent dispersion stability according to the above (1), wherein the poorly water-soluble inorganic fine particles (B) having a particle size of 500 nm or less are fine particles of a Group 2 element compound of the periodic table Aqueous dispersion,
(3) In the presence of a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, (a) a Group 2 element compound in the periodic table (B) Organic weight excellent in dispersion stability as described in (1) above, which is synthesized by reacting one or more compounds selected from organic acids, inorganic acids and salts thereof Coalescence / inorganic fine particle dispersed aqueous solution,
(4) (b) The organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability according to the above (3), wherein the organic or inorganic acid is one or more acids selected from oxo acids and hydrohalic acids,
(5) (a) An organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability according to (3), wherein the group 2 element compound of the periodic table is a calcium compound,
(6) Organic polymer / inorganic having excellent dispersion stability as described in (3) above, wherein the water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group is a polymer of an ethylenically unsaturated compound Fine particle dispersed aqueous solution,
(7) Organic having excellent dispersion stability as described in (6) above, wherein the polymer of the ethylenically unsaturated compound is any one of a (meth) acrylamide polymer, a carboxyl group-modified polyvinyl alcohol, and a vinylpyrrolidone polymer. Polymer / inorganic fine particle dispersed aqueous solution,
(8) A polymer of an ethylenically unsaturated compound is
(1) A (meth) acrylamide polymer that is a polymer of 1 to 100% by weight of an ethylenically unsaturated carboxylic acid amide compound and 0 to 99% by weight of a copolymerizable ethylenically unsaturated compound,
(2) carboxyl group-modified polyvinyl alcohol produced by saponifying a polymer of ethylenically unsaturated carboxylic acid and vinyl acetate, and
(3) One of vinylpyrrolidone polymers which is a polymer of 1 to 99.9% by weight of N-vinyl-2-pyrrolidone and 0.1 to 99% by weight of copolymerizable ethylenically unsaturated compound The organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability as described in (6) above,
(9) The organic polymer / inorganic fine particle dispersion aqueous solution excellent in dispersion stability according to any one of the above (6) to (8), wherein the poorly water-soluble inorganic fine particles (B) are calcium phosphate,
[0018]
(10) In the presence of a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, selected from (a) Group 2 element compounds of the periodic table and (b) organic acids, inorganic acids and salts thereof A method for producing an organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability, wherein the water-insoluble inorganic fine particles (B) having a particle diameter of 500 nm or less are produced by reacting at least one kind of compound,
[0019]
(11) A water-soluble or water-dispersible synthetic polymer compound containing a carboxyl group (A), (a) a periodic table group 2 element compound, and (b) an organic acid, an inorganic acid, and salts thereof Containing hardly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less obtained by reacting the above compounds in a ratio (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) A highly transparent organic polymer / inorganic fine particle composite,
(12) A water-soluble or water-dispersible synthetic polymer compound containing a carboxyl group, which is obtained from the organic polymer / inorganic fine particle-dispersed aqueous solution having excellent dispersion stability described in any one of (1) to (9) above. Organic having excellent transparency containing A) and poorly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less in a ratio of (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) Polymer / inorganic fine particle composite,
(13) The organic polymer / inorganic fine particle composite having excellent transparency according to the above (11) or (12), wherein the composite is a film having excellent transparency,
(14) The water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group is any of a (meth) acrylamide polymer, a carboxyl group-modified polyvinyl alcohol, and a vinylpyrrolidone polymer ( 11) The organic polymer / inorganic fine particle composite having excellent transparency described in the above,
(15) The organic polymer / inorganic fine particle composite having excellent transparency according to the above (11) or (14), wherein the poorly water-soluble inorganic fine particle (B) is calcium phosphate,
[0020]
(16) A water-soluble or water-dispersible synthetic polymer compound containing a carboxyl group (A), (a) a Group 2 element compound of the periodic table, and (b) an organic acid, an inorganic acid, and salts thereof. Containing hardly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less obtained by reacting the above compounds in a ratio (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) Papermaking chemicals,
(17) A papermaking chemical obtained from the organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability according to any one of (1) to (9),
(18) A water-soluble or water-dispersible synthetic polymer compound containing a carboxyl group (A), (a) a periodic table group 2 element compound, and (b) an organic acid, an inorganic acid, and salts thereof Containing hardly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less obtained by reacting the above compounds in a ratio (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) Chemicals for inkjet recording sheets,
(19) A chemical for an ink jet recording sheet obtained from an organic polymer / inorganic fine particle-dispersed aqueous solution having excellent dispersion stability according to any one of (1) to (9),
[0021]
(20) The water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group is any of a (meth) acrylamide polymer, a carboxyl group-modified polyvinyl alcohol, and a vinylpyrrolidone polymer ( 16) or chemicals according to (18),
(21) The chemical according to (16) or (18), wherein the poorly water-soluble inorganic fine particles (B) are calcium phosphate,
(22) Paper obtained using the chemical according to any one of (16) to (21) above,
(23) A cosmetic comprising the organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability according to any one of (1) to (9),
(24) Cosmetics containing an organic polymer / inorganic fine particle composite having excellent transparency according to any one of (11) to (15)
Consists of.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, a poorly water-soluble inorganic fine particle having a particle diameter of 500 nm or less, particularly a Group 2 element compound of a periodic table, an organic acid, an inorganic acid, and their Dispersed aqueous solution composed of organic polymer / inorganic fine particles containing a water-insoluble inorganic fine particle (B) having a particle diameter of 500 nm or less, obtained by reacting one or more compounds selected from salts, and their production Methods and uses.
[0023]
The feature of the present invention is that the water-insoluble or water-dispersible synthetic polymer compound containing a carboxyl group is used in the organic polymer so that the poorly water-soluble inorganic fine particles (B) are stabilized in the aqueous medium of the organic polymer (A). A novel organic polymer / inorganic, in which nanometer-order water-insoluble inorganic fine particles are uniformly dispersed without aggregation or separation in the organic polymer simply by drying the dispersion. The fine particle composite is obtained.
[0024]
The water-soluble or water-dispersible synthetic polymer compound used in the present invention means a compound synthesized by subjecting a raw material to chemical reaction treatment, and is a modified natural polymer material (semi-synthetic polymer). Molecular compounds). The semi-synthetic polymer compound used in the present invention must contain a carboxyl group in the molecule, and examples thereof include carboxymethyl cellulose, carboxymethyl chitin, carboxymethyl starch, and propylene glycol alginate. On the other hand, synthetic polymer compounds synthesized by polymerization reaction using monomers as raw materials are divided into polyolefin chains, polyether chains, polyester chains, polyamine chains, polyamide chains, polyurethane chains, polysilyl ether chains, polysulfones due to differences in the main chain structure. It is classified as a chain. Those having a carboxyl group in the side chain of these main chain structures or those having a carboxyl group at the terminal are the basic structures of the synthetic polymer compound to be the subject of the present invention. Among the polymer compounds having these basic structures, those exhibiting water solubility or water dispersibility are the synthetic polymer compounds that are the subject of the present invention. The main chain structure of the synthetic polymer compound used in the present invention is not particularly limited as long as it has the above basic structure. One of widely used synthetic polymer compounds that are generally water-soluble or water-dispersible is a compound having a polyolefin chain as a main chain. These compounds can be synthesized by radical polymerization or ionic polymerization of an ethylenically unsaturated compound. Any method can be used, but radical polymerization is advantageous from an economical viewpoint.
[0025]
Polymer compounds having a water-soluble or water-dispersible polyolefin chain as the main chain include those obtained by polymerizing hydrophilic monomers such as acrylamides and N-vinyl-2-pyrrolidone, and polyvinyl alcohols. Some of them typically generate a hydrophilic group by a chemical reaction after obtaining a polymer.
As an example of the former, usable hydrophilic monomers include ethylenic nonionic hydrophilic unsaturated compounds and ethylenic ionic unsaturated compounds.
[0026]
Examples of ethylenic nonionic hydrophilic unsaturated compounds include acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N-ethyl. Acrylamide, N-ethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N-propylacrylamide, N-acryloylpyrrolidine, N-acryloylpiperidine, N-acryloylmorpholine, N, N-di-n -Propylacrylamide, Nn-butylacrylamide, Nn-hexylacrylamide, Nn-hexylmethacrylamide, diacetoneacrylamide, Nn-octylacrylamide, Nn-octylmethacrylamide N-tert-octylacrylamide, N-dodecylacrylamide, Nn-dodecylmethacrylamide, N, N-diglycidylacrylamide, N, N-diglycidylmethacrylamide, N- (4-glycidoxybutyl) acrylamide, N -(4-glycidoxybutyl) methacrylamide, N- (5-glycidoxypentyl) acrylamide, N- (6-glycidoxyhexyl) acrylamide, N, N'-methylenebisacrylamide, N, N'- Ethylene bisacrylamide, N, N′-hexamethylene bisacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, maleic diamide, maleic monoamide, difumarate , Fumaric acid monoamide, itaconic acid diamide, itaconic acid monoamide and other unsaturated carboxylic acid amide compounds, N-vinyl-2-pyrrolidone, N-vinyloxazolidone, N-vinyl-5-methyloxazolidone, N-vinylsuccinimide, N-vinylformamide, N-vinylacetamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, allyl alcohol, meta Examples include ril alcohol.
[0027]
Among the unsaturated carboxylic acid amide compounds, those represented by the following general formula (1) or (2) are preferable.
[0028]
[Chemical 1]

[0029]
Among the ionic compounds of the ethylenically hydrophilic unsaturated compound, examples of the anionic compound include an unsaturated carboxylic acid compound, an unsaturated sulfonic acid compound, and other anionic unsaturated compounds. One or more selected compounds. In the present invention, an unsaturated carboxylic acid compound is an essential component, but not only an unsaturated carboxylic acid compound, but also a hydrolysis or the like such as an unsaturated carboxylic acid amide compound or an unsaturated carboxylic acid ester compound. What contains a carboxyl group can be produced | generated by a post reaction may be contained as a copolymerization component, and a carboxyl group may be produced | generated by a post reaction. The unsaturated carboxylic acid compound is generally copolymerized in an amount of 0.1 to 80 mol% or 0.1 to 80 wt%, preferably 0.5 to 50 mol% or 0.5 to 50 wt%, based on the total amount of unsaturated compounds. The
[0030]
Examples of unsaturated carboxylic acid compounds include acrylic acid, methacrylic acid, crotonic acid, angelic acid, tiglic acid, 2-pentenoic acid, β-methylcrotonic acid, β-methyltiglinic acid, α-methyl-2-pentenoic acid, β- Methyl-2-pentenoic acid, maleic acid, fumaric acid, maleic anhydride, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, α-dihydromuconic acid, 2,3-dimethylmaleic acid, 2-methylglutaconic acid, 3 Examples thereof include acids such as -methylglutaconic acid, 2-methyl-α-dihydromuconic acid and 2,3-dimethyl-α-dihydromuconic acid, and alkali metal salts, ammonium salts and organic amine salts thereof.
[0031]
Examples of unsaturated sulfonic acid compounds include sulfonic acids such as vinyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-phenylpropane sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid. And alkali metal salts, ammonium salts, organic amine salts thereof and the like.
Examples of other anionic unsaturated compounds include phosphoric acid such as mono (2-hydroxyethyl) methacrylic acid phosphate, and alkali metal salts, ammonium salts, and organic amine salts thereof.
[0032]
Among the ionic compounds of the ethylenically hydrophilic unsaturated compounds, examples of the compounds showing cationic properties include N, N-dimethylaminoethyl acrylate (DA), N, N-dimethylaminoethyl methacrylate (DM), Basic vinyl compounds such as N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylamide (DMAPAA), N, N-dimethylaminopropyl methacrylamide (DMAPMA) and their salts And allylamines such as allylamine, N-methylallylamine, 2-methylallylamine, diallylamine, and salts thereof. Furthermore, DA, DM, DMAPAA, DMAPMA and the like are dimethyl sulfate, alkyl halides such as methyl chloride and methyl bromide, benzyl halides such as allyl chloride, benzyl chloride and benzyl bromide, epichlorohydrin and epibromohydride. Examples thereof include epihalohydrins such as phosphorus, vinyl compounds quaternized with epoxies such as propylene oxide and styrene oxide, and dimethyldiallylammonium chloride.
[0033]
The ethylenic hydrophilic unsaturated compound can be copolymerized with an ethylenic hydrophobic unsaturated compound to the extent that water solubility or water dispersibility is not impaired. The copolymerization ratio of the hydrophobic unsaturated compound cannot be specified because it varies depending on the type of monomer and the combination of copolymerization. However, since the water solubility is lost when the ratio is increased, the amount of the hydrophobic unsaturated compound is approximately 99 to 0 weight. %, And it is necessary to suppress the water solubility of the copolymer to such an extent that it is not lost.
[0034]
Examples of ethylenically hydrophobic unsaturated compounds include aromatic vinyl compounds, vinyl cyanide compounds, diene compounds, unsaturated carboxylic acid ester compounds, vinyl alkyl ether compounds, other vinyl compounds, and hydrophobic allyl compounds. One or more compounds selected from the group.
[0035]
Aromatic vinyl compounds include styrene, α-methylstyrene, α-chlorostyrene, p-tert-butylstyrene, p-methylstyrene, p-chlorostyrene, o-chlorostyrene, 2,5-dichlorostyrene, 3,4 -Dichlorostyrene, dimethylstyrene, divinylbenzene and the like.
Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile and the like.
Examples of the diene compound include diolefin compounds such as allene, butadiene, and isoprene, and chloroprene.
[0036]
Unsaturated carboxylic acid ester compounds are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, benzyl acrylate , Benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl acrylate, glycidyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene Recall dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol acrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate Ethoxypolyethylene glycol (meth) acrylate, propoxypolyethyleneglycol (meth) acrylate, isopropoxypolyethyleneglycol (meth) acrylate, phenoxypolyethyleneglycol (meth) acrylate, and divinyl compounds such as epoxy acrylates and urethane acrylates it can.
[0037]
Examples of the vinyl alkyl ether compound include vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, vinyl n-propyl ether, vinyl isobutyl ether, vinyl 2-ethylhexyl ether, vinyl n-octadecyl ether and the like.
Other vinyl compounds include vinyl esters such as vinyl acetate and vinyl propionate, olefins such as ethylene, propylene, butene and α-olefin, diene compounds such as butadiene, isoprene and chloroprene, vinyl chloride, vinylidene chloride and fluorine. Halogenated olefins such as vinyl fluoride and vinylidene fluoride, divinyl esters such as divinyl adipate and divinyl sebacate, dialkyl esters such as diethyl fumarate and dimethyl itaconate, maleimide, N-phenylmaleimide, N- Examples thereof include cyclohexylmaleimide.
[0038]
Furthermore, examples of the hydrophobic allyl compound include diallyl isophthalate, diallyl terephthalate, diethylene glycol diallyl carbonate, triallyl cyanurate, and the like.
[0039]
As a method for producing the polymer of the hydrophilic monomer used in the present invention, a known polymerization method such as aqueous solution polymerization, precipitation polymerization, emulsion polymerization or the like can be used. Any combination of batch polymerization and semi-batch polymerization may be used, and the polymerization method is not limited.
[0040]
When carrying out radical polymerization, the polymerization is usually carried out by keeping the polymerization solution at a predetermined temperature in the presence of a radical polymerization initiator. It is not necessary to maintain the same temperature during the polymerization, and it may be changed as the polymerization proceeds, and is performed while heating or removing heat as necessary. The polymerization temperature varies depending on the type of monomer used and the type of polymerization initiator, and is generally in the range of 30 to 100 ° C. in the case of a single initiator, and lower in the case of a redox polymerization initiator. When the polymerization is carried out, the temperature is generally from -5 to 50 ° C, and when added successively, the temperature is generally from 30 to 90 ° C. The atmosphere in the polymerization vessel is not particularly limited, but it is better to substitute with an inert gas such as nitrogen gas in order to perform the polymerization quickly. The polymerization time is not particularly limited, but is generally 1 to 40 hours.
[0041]
Although water is used as the polymerization solvent, an organic solvent such as methanol, ethanol, isopropanol, acetone, ethylene glycol, propylene glycol or the like may be used in combination.
The polymerization concentration is 1 to 40% by weight, preferably 2 to 30% by weight, as the monomer concentration.
[0042]
A general water-soluble initiator can be used as the radical polymerization initiator. Examples of peroxides include ammonium persulfate, potassium persulfate, hydrogen peroxide, tert-butyl peroxide, and the like. In this case, it can be used alone, but can also be used as a redox polymerization agent in combination with a reducing agent. Examples of the reducing agent include salts of low-order ions such as sulfite, bisulfite, iron, copper and cobalt, hypophosphorous acid, hypophosphite, N, N, N ′, N′-tetramethyl Examples thereof include organic amines such as ethylenediamine, and reducing sugars such as aldose and ketose. In the azo compound system, 2,2′-azobis-2-amidinopropane hydrochloride, 2,2′-azobis-2,4-dimethylvaleronitrile, 4,4′-azobis-4-cyanovaleric acid and salts thereof Etc. can be used. Furthermore, two or more kinds of the above polymerization initiators may be used in combination. The addition amount of the polymerization initiator is in the range of 0.0001 to 10% by weight, preferably 0.01 to 8% by weight, based on the monomer. Moreover, in the case of a redox system, the addition amount of a reducing agent with respect to a polymerization initiator is 0.1 to 100%, preferably 0.2 to 80% on a molar basis.
[0043]
For the purpose of adjusting the molecular weight or the polymerization rate, the hydrophilic monomer may be polymerized with a pH adjusting agent, a chain transfer agent, or the like, if necessary.
Examples of pH adjusters include inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia, organic bases such as ethanolamine, trimethylamine and triethylamine, and sodium bicarbonate, sodium carbonate, sodium acetate, sodium dihydrogen phosphate, etc. And the like.
[0044]
As the chain transfer agent, one or a mixture of two or more of isopropyl alcohol, α-thioglycerol, mercaptosuccinic acid, thioglycolic acid, triethylamine, sodium hypophosphite and the like can be appropriately used.
Further, for the purpose of sealing metal ions or adjusting the polymerization rate, a compound such as ethylenediaminetetrasodium sodium acetate (EDTA-Na), urea, or thiourea may be used in combination. The amount of pH adjuster, chain transfer agent, etc. used varies depending on the purpose of use, but is generally 100 ppm to 10% for the pH adjuster and 1.0 ppm to 5 for the chain transfer agent and other additives based on the monomer weight. It is in the range of 0.0%.
[0045]
The molecular weight of a polymer obtained by polymerizing a hydrophilic monomer such as a (meth) acrylamide polymer or a vinylpyrrolidone polymer used in the present invention varies depending on the polymer structure (straight / branched, etc.). Approx 1.0x10^Three~ 5.0 × 10⁶Range. This is because the composite of the present invention is used in various applications, and in applications where the dispersibility of particles is important, it is generally 1.0 × 10.^Three~ 1.0 × 10^Five, 1.0 x 10 for applications that require strength such as various additives and films^Four~ 1.0 × 10⁶, 5.0 x 10 for other applications such as flocculants and paper chemicals^Four~ 5.0 × 10⁶The range of is preferable. 1.0 × 10^ThreeIn the following molecular weight, in addition to the deterioration of the properties of the polymer itself, the adsorptive power to the inorganic fine particles is low, so a stable dispersion solution is not obtained, and 5.0 × 10⁶With the above molecular weight, the cross-linking reaction between the particles takes precedence, so that a stable dispersion solution cannot be obtained. The amount of carboxyl groups contained in the polymer is generally in the range of 0.1 to 80 mol% or 0.1 to 80 wt%, preferably 0.5 to 50 mol% or 0.5 to 50 wt%. .
[0046]
Next, examples of generating a hydrophilic group by chemical reaction after obtaining a polymer include polyvinyl alcohol (PVA) and polyvinylamine, but any polymer compound having a carboxyl group in the molecule can be used. Can also be used. Among them, PVA is most preferable. As PVA, a polyvinyl alcohol polymer having a carboxyl group in the molecule (carboxyl group-modified polyvinyl alcohol) is used, and usually a saponified copolymer of a vinyl ester compound and an ethylenically unsaturated carboxylic acid, And / or a radical copolymerized ethylenically unsaturated carboxylic acid in the presence of a polyvinyl alcohol polymer having a thiol group at the terminal is used.
[0047]
Examples of the vinyl ester compound include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprylate, and the like, but vinyl acetate is preferred industrially.
[0048]
Examples of the ethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, angelic acid, tiglic acid, 2-pentenoic acid, β-methylcrotonic acid, β-methyltiglinic acid, α-methyl-2-pentenoic acid, Unsaturated monocarboxylic acids such as β-methyl-2-pentenoic acid, maleic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, glutaconic acid, α-dihydromuconic acid , Unsaturated dicarboxylic acids such as 2,3-dimethylmaleic acid, 2-methylglutaconic acid, 3-methylglutaconic acid, 2-methyl-α-dihydromuconic acid, 2,3-dimethyl-α-dihydromuconic acid, and the like Examples thereof include alkali metal salts, ammonium salts, and organic amine salts.
[0049]
In addition, instead of ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid ester, ethylenically unsaturated dicarboxylic acid monoester, ethylenically unsaturated dicarboxylic acid diester, ethylenically unsaturated A carboxylic acid amide or the like may be copolymerized. In addition, an ethylenically unsaturated carboxylic acid and a compound that generates a carboxyl group during the saponification reaction may be copolymerized together. Furthermore, it is possible to copolymerize with other copolymerizable monomers to such an extent that the water solubility and stability of the carboxyl group-modified polyvinyl alcohol are not hindered.
[0050]
The polymerization and saponification methods are not particularly limited, and carboxyl group-modified polyvinyl alcohol can be produced according to a known method as disclosed in, for example, JP-A-53-91995.
[0051]
A polyvinyl alcohol polymer having a thiol group at the terminal can be obtained by polymerizing a vinyl ester compound in the presence of a chain transfer agent containing a thiol group such as thioacetic acid and then performing a saponification reaction. In the polymerization, it is also possible to copolymerize with a monomer that can be copolymerized to such an extent that the water solubility and stability of the carboxyl group-modified polyvinyl alcohol are not hindered. Carboxyl group-modified polyvinyl alcohol (block copolymer) is produced by radical copolymerization of an ethylenically unsaturated carboxylic acid in the presence of a polyvinyl alcohol polymer having a thiol group at the terminal. In these block polymerizations, it is possible to copolymerize a copolymerizable monomer to such an extent that the water solubility and stability of the carboxyl group-modified polyvinyl alcohol are not hindered. The amount varies depending on the type of monomer used, but is generally in the range of 1 to 50% by weight based on the vinyl ester compound before the saponification reaction.
[0052]
Copolymerizable monomers include ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid ester, ethylenically unsaturated dicarboxylic acid monoester, ethylenically unsaturated dicarboxylic acid diester, ethylenically unsaturated carboxylic acid amide, anionic And ethylenically unsaturated compounds, cationic ethylenically unsaturated compounds, nonionic ethylenically hydrophilic unsaturated compounds, and ethylenically hydrophobic unsaturated compounds.
[0053]
Ethylenically unsaturated carboxylic acid esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, benzyl Acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl acrylate, glycidyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethyl Glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol acrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) Acrylate, ethoxypolyethylene glycol (meth) acrylate, propoxypolyethyleneglycol (meth) acrylate, isopropoxypolyethyleneglycol (meth) acrylate, phenoxypolyethyleneglycol (meth) acrylate, and divinyl compounds such as epoxy acrylates and urethane acrylates Can do.
[0054]
Examples of the ethylenically unsaturated dicarboxylic acid monoester used in the present invention include maleic acid monoalkyl ester, fumaric acid monoalkyl ester, itaconic acid monoalkyl ester, and citraconic acid monoalkyl ester.
Examples of ethylenically unsaturated dicarboxylic acid diesters include maleic acid dialkyl esters, fumaric acid dialkyl esters, itaconic acid dialkyl esters, and citraconic acid dialkyl esters.
[0055]
Examples of ethylenically unsaturated carboxylic acid amides include acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N-ethylacrylamide, N- Ethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N-propylacrylamide, N-acryloylpyrrolidine, N-acryloylpiperidine, N-acryloylhexahydroazepine, N-acryloylmorpholine, N, N- Di-n-propylacrylamide, Nn-butylacrylamide, Nn-hexylacrylamide, Nn-hexylmethacrylamide, diacetoneacrylamide, Nn-octylacrylamide, N n-octylmethacrylamide, N-tert-octylacrylamide, N-dodecylacrylamide, Nn-dodecylmethacrylamide, N, N-diglycidylacrylamide, N, N-diglycidylmethacrylamide, N- (4-glycid Xylbutyl) acrylamide, N- (4-glycidoxybutyl) methacrylamide, N- (5-glycidoxypentyl) acrylamide, N- (6-glycidoxyhexyl) acrylamide, N, N′-methylenebisacrylamide N, N′-ethylenebisacrylamide, N, N′-hexamethylenebisacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, maleic acid diamide, male Phosphate monoamide, fumaric acid diamide, fumaric acid monoamide, diamide itaconic acid, it is possible to increase the itaconic acid Minoamido like.
[0056]
Examples of the anionic ethylenically unsaturated compound other than the above-described ethylenically unsaturated carboxylic acid include ethylenically unsaturated sulfonic acid and other anionic unsaturated compounds, and one or more selected from these groups A compound is used.
[0057]
Examples of the ethylenically unsaturated sulfonic acid include sulfones such as vinyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-phenylpropane sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid. Examples thereof include acids and alkali metal salts, ammonium salts and organic amine salts thereof.
Examples of other anionic unsaturated compounds include phosphoric acid such as mono (2-hydroxyethyl) methacrylic acid phosphate, and alkali metal salts, ammonium salts, and organic amine salts thereof.
[0058]
Cationic ethylenically unsaturated compounds include N, N-dimethylaminoethyl acrylate (DA), N, N-dimethylaminoethyl methacrylate (DM), N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, Basic vinyl compounds such as N, N-dimethylaminopropylacrylamide (DMAPAA), N, N-dimethylaminopropylmethacrylamide (DMAPMA) and their salts, and allylamine, N-methylallylamine, 2-methylallylamine, diallylamine, etc. Allylamines and their salts. Furthermore, DA, DM, DMAPAA, DMAPMA, etc., such as dimethyl sulfate, alkyl halides such as methyl chloride and methyl bromide, benzyl halides such as allyl chloride, benzyl chloride and benzyl bromide, epichlorohydrin, epibromohydrin, etc. Examples thereof include epihalohydrins, vinyl compounds quaternized with epoxies such as propylene oxide and styrene oxide, and dimethyldiallylammonium chloride.
[0059]
Nonionic ethylenically hydrophilic unsaturated compounds include N-vinyl-2-pyrrolidone, N-vinyloxazolidone, N-vinyl-5-methyloxazolidone, N-vinylsuccinimide, N-vinylformamide, N-vinylacetamide, N-vinylcaprolactam, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, allyl alcohol, methallyl alcohol, etc. be able to.
[0060]
Ethylenically hydrophobic unsaturated compounds other than ethylenically unsaturated carboxylic acid esters and vinyl ester compounds include aromatic vinyl compounds, vinyl cyanide compounds, diene compounds, vinyl alkyl ether compounds, other vinyl compounds, and hydrophobic compounds. One or more compounds selected from the group consisting of allyl compounds.
[0061]
Aromatic vinyl compounds include styrene, α-methylstyrene, α-chlorostyrene, p-tert-butylstyrene, p-methylstyrene, p-chlorostyrene, o-chlorostyrene, 2,5-dichlorostyrene, 3,4 -Dichlorostyrene, dimethylstyrene, divinylbenzene and the like.
Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile and the like.
[0062]
Examples of the diene compound include diolefin compounds such as allene, butadiene, and isoprene, and chloroprene.
Examples of the vinyl alkyl ether compound include vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, vinyl n-propyl ether, vinyl isobutyl ether, vinyl 2-ethylhexyl ether, vinyl n-octadecyl ether and the like.
[0063]
Other vinyl compounds include olefins such as ethylene, propylene, butene and α-olefin, halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride, divinyl adipate, divinyl sebacate, etc. Examples thereof include divinyl esters, carboxylic acid dialkyl esters such as diethyl fumarate and dimethyl itaconate, maleimide, N-phenylmaleimide, N-cyclohexylmaleimide and the like.
Examples of the hydrophobic allyl compound include diallyl isophthalate, diallyl terephthalate, diethylene glycol diallyl carbonate, triallyl cyanurate, and the like.
[0064]
The degree of polymerization of the carboxyl group-modified polyvinyl alcohol used in the present invention is generally 100 to 5000, preferably 200 to 3000, the degree of saponification is 60 to 100 mol% with respect to the vinyl ester compound before saponification, and the carboxyl group content. Is in the range of 0.05 to 50 mol%, preferably 0.1 to 30 mol%.
[0065]
Among the water-dispersible synthetic polymer compounds, those in the form of so-called synthetic latex and emulsion are also included. Polybutadiene latex, styrene-butadiene latex, acrylonitrile-butadiene latex, methyl methacrylate-butadiene latex, 2-vinylpyridine-styrene-butadiene latex, chloroprene latex, isoprene latex, polystyrene emulsion, urethane emulsion, acrylic emulsion, vinyl acetate Among the water-based emulsions, vinyl acetate-ethylene (EVA) emulsions, acrylate-styrene emulsions, vinyl chloride latexes, vinylidene chloride latexes, epoxy emulsions, and the like that have been modified with a carboxyl group Corresponds to dispersible synthetic polymer compounds.
[0066]
In the present invention, the synthetic polymer compound containing a carboxyl group that is preferably used is preferably a polymer of an ethylenically unsaturated compound, particularly a (meth) acrylamide polymer, a carboxyl group-modified polyvinyl alcohol, and a vinylpyrrolidone polymer. ,further
(1) A (meth) acrylamide polymer that is a polymer of 1 to 100% by weight of an ethylenically unsaturated carboxylic acid amide compound and 0 to 99% by weight of a copolymerizable ethylenically unsaturated compound,
(2) Carboxyl group-modified polyvinyl alcohol produced by saponifying a polymer of ethylenically unsaturated carboxylic acid and vinyl acetate,
(3) A vinylpyrrolidone polymer which is a polymer of 1 to 99.9% by weight of N-vinyl-2-pyrrolidone and 0.1 to 99% by weight of a copolymerizable ethylenically unsaturated compound is preferred.
[0067]
The poorly water-soluble inorganic fine particles of the present invention are not limited as long as the particle diameter is 500 nm or less, but are preferably fine particles of Group 2 element compounds of the periodic table, more preferably Group 2 element compounds of the periodic table, organic acids, inorganic acids and their It is obtained by reacting one or more compounds selected from salts. The periodic table group 2 elements include beryllium, magnesium, calcium, strontium, barium, and radium. Since chemical properties are similar, one or more elements selected from these can be used. Of these, magnesium, calcium, strontium and barium are preferred. More preferably, it is calcium.
[0068]
As a method for synthesizing the inorganic fine particles, a liquid phase synthesis method is preferable. This is a so-called precipitation method, which is a poorly water-soluble inorganic substance by reacting an organic acid, an inorganic acid or a salt thereof with an aqueous solution or suspension of a periodic table group 2 element compound that is soluble or hardly soluble in water. Fine particles are synthesized. As referred to as the precipitation method, usually generated poorly water-soluble inorganic fine particles are precipitated, and after filtration, are dried or thermally decomposed to obtain a powder. In the present invention, the above water-soluble inorganic fine particles are contained. Alternatively, by allowing the water-dispersible synthetic polymer compound to be present, an organic polymer / inorganic fine particle-dispersed aqueous solution having excellent dispersion stability dispersed uniformly in a colloidal form without precipitation is obtained. The reason why such an organic polymer / inorganic fine particle-dispersed aqueous solution with excellent dispersion stability is not completely elucidated, but in the periodic table group 2 elements and synthetic polymer compounds constituting the inorganic fine particles. It is suggested from the experimental results of the present inventors that the carboxyl group of the compound is bonded by an ionic interaction. Therefore, crystal growth is suppressed, the particle diameter does not increase to 500 nm or more, and the bonded polymer compound This is because the aggregation between particles is suppressed due to the protective colloidal action.
[0069]
The poorly water-soluble inorganic fine particles of the present invention have a water solubility at 20 ° C. of about 3.0 (% by weight) or less, and include water-insoluble inorganic fine particles. Depending on the type of group 2 element in the periodic table, for example, magnesium, hydroxide, fluoride, carbonate, oxalate, phosphate, etc., calcium, fluoride, sulfate, phosphate, carbonate , Silicate, oxalate, hydroxide, etc., strontium, fluoride, carbonate, oxalate, sulfate, phosphate, hydroxide, etc., barium, carbonate, sulfate, Examples thereof include phosphate and oxalate.
[0070]
Examples of Periodic Table Group 2 element compounds used for the synthesis of the poorly water-soluble inorganic fine particles of the present invention include magnesium acetate, magnesium carbonate, magnesium chloride, magnesium fluorosilicate, magnesium hydroxide, magnesium oxide, magnesium nitrate, magnesium sulfate, Calcium acetate, calcium dihydrogen phosphate, calcium lactate, calcium citrate, calcium hydroxide, calcium carbonate, calcium chloride, calcium nitrate, calcium sulfate, calcium thiosulfate, strontium hydroxide, strontium carbonate, strontium nitrate, strontium chloride, acetic acid Examples thereof include one or more compounds selected from barium, barium chloride, barium nitrate, barium sulfate, barium hydroxide, barium fluoride, and the like.
[0071]
The inorganic acid, organic acid, and salts thereof used in the present invention may be those that react with the Group 2 element compound of the periodic table to produce poorly water-soluble inorganic fine particles. Of these, oxoacids, hydrohalic acids and salts thereof are preferred.
[0072]
Examples of oxo acids include boric acid, metaboric acid, carbonic acid, isocyanic acid, thunderic acid, orthosilicic acid, metasilicic acid, nitric acid, nitrous acid, phosphoric acid (orthophosphoric acid), pyrophosphoric acid (diphosphoric acid), metaphosphoric acid, Phosphonic acid (phosphorous acid), diphosphonic acid (diphosphorous acid), phosphinic acid (hypophosphorous acid), sulfuric acid, disulfuric acid, thiosulfuric acid, sulfurous acid, chromic acid, dichromic acid, perchloric acid, formic acid, acetic acid Propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, lactic acid, malic acid, tartaric acid, benzoic acid, phthalic acid and the like.
[0073]
Examples of hydrohalic acid include hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, and the like.
Examples of salts of oxo acid and hydrohalic acid include alkali metal salts, alkaline earth metal salts, ammonium salts, and organic amine salts thereof.
[0074]
As inorganic components of animal bone shells, calcium carbonate contained in shells and the like, and calcium phosphate contained in bones, teeth, fish phosphorus, and the like are main components of organic / inorganic complexes found in the living body. Among the poorly water-soluble fine particles, calcium compounds such as calcium phosphate and calcium carbonate are particularly preferably used because of their high affinity with organic substances.
[0075]
Although the case where the poorly water-soluble inorganic fine particles are calcium phosphate will be described in detail below, the basic operation and the like are only different in the raw material used in the case of the calcium compound, and may be carried out in the same manner. Further, in the case of other group 2 element compounds, only the raw materials used are different, and the same may be done.
The calcium phosphate contained in the dispersed aqueous solution of the present invention contains 50 wt% or more of the total of the portion derived from phosphoric acid and calcium atoms. Examples include hydroxyapatite, fluorapatite, chlorapatite, carbonate-containing apatite, magnesium-containing apatite, iron-containing apatite and other apatite compounds, tricalcium phosphate and the like.
[0076]
The apatite compound contained in the calcium phosphate of the present invention has a basic composition of M_x(RO_Four)_yX_zIt is represented by M site is calcium ion (Ca²⁺), RO_FourThe site is phosphate ion (PO_Four ^3-), X site is hydroxide ion (OH^-), X = 10, y = 6, z = 2, which is a compound generally called hydroxyapatite. M, RO_Four, X sites can be replaced with various ions and can also be vacancies. The amount of substitution and the amount of vacancies vary depending on the type of ions, etc., but if the total of the portion derived from phosphoric acid and the calcium atom is contained by 50% by weight or more, even if it is substituted with other ions, It can be a hole.
[0077]
If the total of the portion derived from phosphoric acid and the calcium atom is less than 50% by weight, the properties as calcium phosphate may be lost, which is not preferable. M site is basically Ca²⁺However, as an example of a replaceable ionic species, H⁺, Na⁺, K⁺, H_ThreeO⁺, Sr²⁺, Ba²⁺, Cd²⁺, Pb²⁺, Zn²⁺, Mg²⁺, Fe²⁺, Mn²⁺, Ni²⁺, Cu²⁺, Hg²⁺, Ra²⁺, Al³⁺, Fe³⁺, Y³⁺, Ce³⁺, Nd³⁺, La³⁺, Dy³⁺, Eu³⁺, Zr⁴⁺Etc. RO_FourThe site is basically PO_Four ^3-However, as an example of substitutable ionic species, SO_Four ^2-, CO_Three ^2-, HPO_Four ^2-, PO_ThreeF^2-, AsO_Four ^3-, VO_Four ^3-, CrO_Four ^3-, BO_Three ^3-, SiO_Four ^Four-, GeO_Four ^Four-, BO_Four ^Five-AlO_Four ^Five-, H_FourO_Four ^Four-Etc. Examples of ionic species and molecules entering the X site include OH^-, F^-, Cl^-, Br^-, I^-, O^2-, CO_Three ^2-, H₂O and the like.
[0078]
The particle size of calcium phosphate contained in the aqueous dispersion of the present invention is 500 nm or less. When the particle diameter exceeds 500 nm, the particles are liable to settle and separate from the aqueous dispersion, and the stability of the aqueous dispersion is insufficient. Further, the calcium phosphate crystal structure may be anything, and may be amorphous. Further, the shape of the calcium phosphate is not particularly limited, and may be any shape such as a spherical shape, a needle shape, a column shape, or an indefinite shape. The particle size distribution is not particularly limited as long as the particle size is 500 nm or less. The particle size used here indicates the major axis diameter of the particles.
[0079]
In order to obtain a dispersion having excellent dispersion stability in a method (composite) for producing a water-soluble or water-dispersible polymer compound / calcium phosphate fine particle-dispersed aqueous solution containing a carboxyl group, It is particularly preferable to produce the polymer in the presence of a water-soluble or water-dispersible polymer, which is a feature of the present invention. The calcium phosphate can be produced by any method as long as it can be produced in the presence of a water-soluble or water-dispersible polymer compound containing a carboxyl group, but the so-called wet method (liquid phase method / precipitation method). Is preferred. The wet method is a method of synthesizing calcium phosphate by mixing a calcium compound (suspension) aqueous solution and phosphoric acid or a phosphate aqueous solution. Generally, both solutions are dropped simultaneously or one solution is added into another solution. The method of dropping the solution is used. Although there is no restriction | limiting in particular about dripping time, It is 5 minutes-about 24 hours in general. The reaction is aged as necessary after completion of the dropping.
[0080]
A water-soluble or water-dispersible polymer compound containing a carboxyl group may be present in a reaction solution in which calcium phosphate is produced, and mixed with either a calcium compound (suspension) aqueous solution, phosphoric acid or a phosphate aqueous solution. It may be left or may be mixed in both. Moreover, you may add continuously or intermittently into a reactor separately from both. However, particularly when the polymer compound contains a component that undergoes an alkaline hydrolysis reaction, such as when complexing carboxyl group-modified polyvinyl alcohol having a large unsaponified part content (generally 5 to 60 mol%), Care must be taken when a highly alkaline substance such as calcium hydroxide is used as a raw material. For example, when calcium hydroxide and carboxyl group-modified polyvinyl alcohol are mixed, a hydrolysis reaction of an unsaponified portion occurs as a side reaction, which may be a problem. In such a case, the amount of phosphoric acid consumed by the hydrolysis reaction of calcium hydroxide becomes excessive, leading to a decrease in pH of the reaction solution, resulting in incomplete generation of calcium phosphate and poor complexation. The reaction solution may be separated or settled. In order to solve this problem, calcium hydroxide and carboxyl group-modified polyvinyl alcohol may be divided and both or one of them may be dropped, and the side reaction can be suppressed because the reaction of calcium phosphate has priority. By this method, a carboxyl group-modified polyvinyl alcohol / calcium phosphate dispersed aqueous solution containing an unsaponified portion can be produced. If the effect of sodium acetate or the like caused by saponification is not a problem, an amount of alkali corresponding to the unsaponified portion may be added, and a saponification reaction may be performed in advance, and then a complexing reaction may be performed. Since influences such as coloring due to impurities can be suppressed, it is preferable to use a completely saponified type carboxyl group-modified polyvinyl alcohol. However, those that generate a carboxyl group by a hydrolysis reaction, such as a (meth) acrylamide polymer, may cause the hydrolysis reaction to be more positive during the complexing reaction.
[0081]
Examples of calcium salts used in the synthesis include calcium chloride, calcium nitrate, calcium acetate, calcium hydroxide, calcium carbonate, calcium sulfate dihydrate, and the like. Examples of the phosphate include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and sodium and potassium salts other than ammonium salts. Organic or inorganic salts that are by-produced during the reaction other than the target compound must be removed depending on the application, and in that case, they are desalted by a known method such as dialysis. When calcium phosphate is used as the target compound, it is particularly preferable that calcium hydroxide and phosphoric acid are used as raw materials because no by-product salt is generated. Also, among calcium phosphates, those having an apatite structure are known to be able to replace various ions as described above due to the flexibility of the structure, and if necessary, compounds containing ionic species other than calcium and phosphate are used in combination. You can also.
[0082]
The weight ratio of the water-soluble or water-dispersible polymer compound containing a carboxyl group and calcium phosphate is 10:90 to 99.99: 0.01, preferably 20:80 to 99.99: 0.01, more preferably 30. : It is the range of 70-99: 1. If the amount of calcium phosphate is less than 0.01%, the effect of adding calcium phosphate is poor, and if it exceeds 90%, dispersion stability is poor, precipitation and separation are likely to occur, and a uniform complex cannot be formed.
[0083]
Usually, the reaction is carried out by keeping the reaction solution at a predetermined temperature. It is not necessary to maintain the same temperature during the reaction, and it may be appropriately changed as the reaction proceeds, and is performed while heating or cooling as necessary. Since the size of the calcium phosphate particles generated varies depending on the reaction temperature, the particle size can be changed by changing the reaction temperature, and as a result, the transparency of the film prepared from the dispersed aqueous solution can be adjusted. The reaction temperature is generally in the range of 5 to 95 ° C. The atmosphere in the reactor is not particularly limited and is usually carried out in air. However, in order to control the composition of calcium phosphate, it is better to substitute with an inert gas such as nitrogen gas. The synthesis time is not particularly limited, but is generally 1 to 120 hours including the dropping and aging time.
[0084]
The stirring method is not particularly limited as long as it is a uniformly mixed method, and examples thereof include a rotation method and an ultrasonic method. In the case of using a batch-type reaction vessel using a stirring blade, it is unclear because it is affected by the shape of the stirring blade, the solution viscosity, and the like, but the stirring speed is generally in the range of 30 to 10,000 rpm.
[0085]
Although water is used as the reaction solvent, an organic solvent such as methanol, ethanol, isopropanol, acetone, ethylene glycol, propylene glycol, or glycerin may be used in combination.
[0086]
The concentration at the time of synthesis is not particularly limited, but it is generally in the range of 0.5 to 60% by weight, preferably 1 in terms of the solid content of the water-soluble or water-dispersible polymer compound containing calcium phosphate and carboxyl group. It is in the range of ˜50% by weight. If it exceeds 50% by weight, the viscosity of the dispersion becomes high and handling may be difficult.
[0087]
Since calcium phosphate produces different types of calcium phosphate depending on the pH at the time of reaction, it may be carried out while adjusting the pH when producing a specific species. The pH can be adjusted with ammonia gas, aqueous ammonia, sodium hydroxide, potassium hydroxide or the like. In particular, (1) when the target compound is dissolved by a change in pH, and (2) when the complex is separated by a change in the dissociation state of the carboxyl group, it is necessary to strictly adjust the pH. For example, in the case of hydroxyapatite (calcium phosphate), after the reaction, it is adjusted by adding an appropriate alkali so that the pH does not become 5 or less for the reason (2).
[0088]
The water-soluble or water-dispersible polymer compound / calcium phosphate fine particle-dispersed aqueous solution containing a carboxyl group having excellent stability thus obtained is a uniform emulsion solution, and does not precipitate or separate even after standing for a long time. . The term "excellent in stability" as used herein means that the weight of solid matter that settles or separates after production is 1% by weight or less after one month, excluding precipitated particles mixed immediately after production (sedimentation after standing overnight). Or the one that does not cause sedimentation or separation even after centrifugation at 2000 rpm for 10 minutes.
[0089]
When the poorly water-soluble inorganic fine particles are calcium carbonate, they are produced by the same method as calcium phosphate. In this case, the same raw material as calcium phosphate can be used as the calcium source, and carbon dioxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, ammonium carbonate and the like are appropriately used as the carbonic acid source. As in the case of calcium phosphate, a combination of calcium hydroxide and carbonic acid (gas) is preferable in order not to generate a by-product salt.
[0090]
The water-soluble or water-dispersible polymer compound / calcium phosphate complex containing a carboxyl group having excellent transparency of the present invention is highly water-soluble or water-dispersible containing a carboxyl group having excellent dispersion stability. It is solidified by removing water from the molecular compound / calcium phosphate fine particle dispersion. The composite can be processed into an arbitrary shape such as a film shape, a sheet shape, a powder shape, a foam shape, and a thread shape by a known method and apparatus depending on the application.
It can also be processed into a gel-like composite by a method of physically creating a cross-linked structure by temperature change or a method of creating a cross-linked structure by chemical bonds (ionic bonds, covalent bonds) using a cross-linking agent. It is.
[0091]
For example, in the case of processing into a film, the dispersion aqueous solution is used as it is, or a known plasticizer such as ethylene glycol or glycerin, a crosslinking agent, a thickener, a filler, or a colorant as it is, concentration treatment or pH adjustment. After mixing additives such as antioxidants, UV absorbers, heat stabilizers, etc., the above-mentioned stable dispersion liquid is placed on substrates such as glass, quartz, metal, ceramics, plastics, rubber, rolls, belts, etc. It can be produced by coating and forming a film and evaporating water and / or a water-based solvent by performing treatments such as heating, decompression, air supply, infrared irradiation, and ultra-high frequency irradiation as necessary. The coating method is not particularly limited, and there are a flow coating method, a dipping method, a spray method, etc., and a known coating machine such as a bar coater, spin coater, knife coater, blade coater, curtain coater, gravure coater, spray coater, etc. it can. The coating thickness (thickness before drying) is approximately 1 μm to 10 mm, and the thickness can be arbitrarily set by selecting a coating method. The temperature for evaporating water and / or the aqueous solvent is 0 to 150 ° C., and it is carried out under normal pressure or reduced pressure. At that time, the drying time can be shortened by circulating dry air or dry nitrogen. Furthermore, when the crosslinking reaction is promoted for the purpose of imparting water resistance, heat treatment is performed at 40 to 200 ° C. for several seconds to several tens of minutes. When the film is peeled off from the base material, the release property is good when a plastic base material is used. However, when other base materials are used, a known release may be applied to each material as necessary. A mold may be applied in advance. The film thus produced has a feature of excellent transparency. This indicates that the size of the calcium phosphate fine particles is equal to or smaller than the wavelength region of visible light, and the individual particles are uniformly dispersed in the polymer matrix without causing aggregation. The transparency can be quantitatively evaluated by the visible light transmittance at 400 nm and 700 nm. The term “excellent in transparency” as used herein refers to a film having a light transmittance of 50% or more at a wavelength of 700 nm when the film thickness is 30 to 300 μm. This film becomes cloudy when it absorbs moisture and becomes transparent when dried. The expression that this change is reversible and excellent in transparency is a description of dry conditions (water content of 10% by weight or less).
[0092]
Further, this transparent film is redispersed in water without special treatment such as crosslinking. The redispersibility is particularly remarkable for (meth) acrylamide polymers. The reason why the dispersion stability is extremely excellent, such as re-dispersion of the film once formed in this way, is not clear, but the adsorption action mediated by ionic bonds between the polymer and the particles as described above. It is thought to support the existence of protective colloidal action.
[0093]
The film is very hydrophilic and may cause problems with water resistance. In such cases, (1) a method of physically preventing water and moisture from entering, and (2) water resistance during film production. There is a method to give. For (1), a method of laminating a hydrophobic film is effective. (2) includes a method in which a water-dispersed solution of a water-soluble or water-dispersible polymer compound / inorganic fine particle containing a carboxyl group itself has crosslinking reactivity, and a method in which a water-resistant agent is added. Specifically, the former includes (I) a method of introducing a crosslinkable functional group by copolymerization when producing a water-soluble or water-dispersible polymer compound containing a carboxyl group, and (II) a water solution containing a carboxyl group. There is a method of adding a crosslinking agent capable of reacting with a water-soluble or water-dispersible polymer compound. In (I), a carboxyl group, an amino group, an epoxy group, a hydroxyl group, an oxazoline group or the like is used as a functional group, and water resistance is brought about by a reaction between these functional groups or a crosslinking reaction with a polyvalent metal ion. Examples of (II) include formalin, urea-formalin resin, polyamide-polyamine resin, and modified products thereof. The latter includes a method in which a curable emulsion resin is mixed with a dispersed aqueous solution, and known acrylic, polyester, and polyurethane emulsions can be used.
[0094]
The method of pulverizing a composite from an aqueous dispersion of a water-soluble or water-dispersible polymer compound / inorganic fine particle containing a carboxyl group is the same as that for film processing. , After mixing known plasticizers such as ethylene glycol and glycerin, and additives such as crosslinking agents, thickeners, fillers, colorants, antioxidants, ultraviolet absorbers, heat stabilizers, etc. Use a method of directly evaporating the solvent from the dispersion, such as spray drying or freeze drying, or an organic solvent such as methanol that is miscible with water but does not dissolve the complex, or a compound with a high salting-out effect such as sodium sulfate. A method of performing solid separation treatment and then pulverizing after drying is also possible, but the former is preferred from the gist of the present invention.
[0095]
For other shape processing, as in the film processing, the aqueous dispersion of the complex is used as it is, or a known plasticizer such as ethylene glycol or glycerin, a crosslinking agent, or a thickener as it is, concentration treatment or pH adjustment. In addition, after mixing additives such as a filler, a colorant, an antioxidant, an ultraviolet absorber, and a heat stabilizer, it can be carried out by a known method.
[0096]
The water-soluble or water-dispersible polymer compound / inorganic fine particle composite containing a carboxyl group according to the present invention is known to be a highly safe polymer material particularly with respect to polyvinyl alcohol, polyvinyl pyrrolidone and the like. When the chemical partner is calcium phosphate or calcium carbonate, it is characterized in that it is a “polymer composite material in which particles having high biocompatibility are uniformly mixed and dispersed in a nanometer size” and has various applications. Since these composites can be processed into various shapes as described above, they are particularly useful materials as medical or cosmetic materials. As a medical material, it can be used as an artificial bone material, a bone filler, a dental material, a DDS carrier, a skin disease treatment drug and the like. Furthermore, as described above, these composite films have the characteristic of becoming cloudy when absorbing water and returning to a transparent film when dried. This is due to scattering accompanying particle hydration, and is not limited to a film phenomenon. If this property is used, it can be used for cosmetics with high UV light shielding properties, window materials whose humidity changes reversibly depending on humidity, humidity sensors, and the like.
[0097]
Thus, cosmetics containing the polymer compound / inorganic fine particle dispersion aqueous solution having excellent dispersion stability and the polymer compound / inorganic fine particle composite having excellent transparency are also one aspect of the present invention.
[0098]
The water-soluble or water-dispersible polymer compound / inorganic fine particle composite containing a carboxyl group of the present invention has improved tensile strength, hardness, thermal properties, gas barrier properties, and the like as compared with the polymer alone film before the composite. For example, polyvinyl alcohol is known as a material having a high gas barrier property, but the barrier property is greatly improved by the composite as compared with it. In order to utilize these properties, it can be solved by making a multilayer film with polyvinyl alcohol having poor water resistance as an intermediate layer, but in applications where water resistance is not a problem, water resistance treatment can be applied as necessary. The surface layer may be coated. In addition, there is an advantage that the strength of the film itself is increased, but by applying and impregnating it to various substrates, it can also be used for the purpose of improving the strength of the substrate, and among them, it was applied to paper. The papermaking chemicals are one of the present invention.
[0099]
The papermaking chemical of the present invention is obtained from the polymer compound / inorganic fine particle dispersion aqueous solution having excellent dispersion stability. The papermaking chemical of the present invention is selected from a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, a group 2 element compound of the periodic table, an organic acid, an inorganic acid, and salts thereof. The hardly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less obtained by reacting a compound of at least species with (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio). It is a chemical for papermaking.
[0100]
The paper strength performance of the paper obtained using the papermaking chemical of the present invention is improved. In particular, by applying (externally adding) the papermaking chemical of the present invention to the surface of paper, the paper strength is greatly improved. The concentration of the coating solution for coating on paper is in the range of 0.01 to 20.0% by weight, preferably 0.10 to 10.0% by weight. The coating amount is 0.001 to 20.0 g / m.², Preferably 0.005 to 10.0 g / m²It is in the range. For coating on paper, general methods such as impregnation, size press, gate roll coater, calender, blade coater, and spray are used. The drying temperature after coating may be a temperature at which water evaporates, and is preferably in the range of 100 ° C to 180 ° C. Furthermore, the chemicals for papermaking of the present invention can further improve the surface strength and internal strength by combining with conventionally known chemicals for surface coating such as starch, carboxymethylcellulose, PVA, and PAM. .
[0101]
The paper-making chemicals of the present invention include water-soluble polymers having cationic groups such as aluminum sulfate, aluminum chloride, sodium aluminate, polyethyleneimine, polyacrylamide Mannich modified products, Hoffman modified products, polyalkylene polyamines, and cationized starch. It can be fixed to the pulp by interaction with the above, and can also be used as an internal additive for papermaking. When used as an internal chemical, it is added in an amount of 0.01 to 5.0% by weight, preferably 0.05 to 2.0% by weight, based on the pulp weight. What is necessary is just to add in the place similar to a chemical | medical agent.
The paper-making chemicals of the present invention may be mixed with an antifoaming agent, an antiseptic, a rust-preventing agent, an anti-slip agent, or the like, if necessary.
[0102]
Calcium phosphate and calcium carbonate are known to have high affinity with organic substances as well as living organisms. Unlike the conventional ones, the nanometer-sized calcium phosphate particles in the composite of the present invention are uniformly dispersed in the composite without forming an aggregated structure, so that the specific surface area is greatly improved and contained in water. Since the interaction with the organic substance is increased, it can be suitably used, for example, for an ink jet recording material, and an ink jet recording sheet chemical is also included in the present invention.
[0103]
The chemical | medical agent for inkjet recording sheets of this invention is obtained from the polymer compound / inorganic fine particle dispersion aqueous solution which is excellent in the said dispersion stability. The ink jet recording sheet chemical of the present invention is selected from a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, a periodic table group 2 element compound, an organic acid, an inorganic acid, and salts thereof. (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) obtained by reacting one or more of the above compounds with a slightly water-soluble inorganic fine particle (B) having a particle size of 500 nm or less. Inkjet recording sheet chemicals.
The ink jet recording sheet chemical of the present invention has a very excellent feature with respect to the problem of yellowing that causes the paper to turn yellow with respect to long-term storage of conventionally used inorganic fillers.
[0104]
The chemical | medical agent for inkjet recording sheets of this invention can manufacture the sheet | seat for inkjet recording excellent in yellowing resistance by apply | coating to a sheet | seat base material. The sheet base material is not particularly limited, and pulp, pulp-based paper, recycled paper, synthetic paper, cloth, non-woven fabric, polyolefin, acrylic polymer, polyester-based film, plate, glass plate, etc. can give.
[0105]
The ink jet recording sheet chemicals of the present invention may be used alone, or may use known inorganic fillers, organic fillers, binders, and other various additives as long as they do not impair yellowing resistance. it can. Inorganic fillers include calcium carbonate, kaolin, clay, talc, mica, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, zeolite, smectite, diatomaceous earth, calcium silicate, aluminum silicate Amorphous silica, alumina and the like, and organic fillers include styrene-based and urea resin-based plastic pigments. Examples of the binder include polyvinyl alcohol, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, polyvinylpyrrolidone, water-soluble acrylic resin, casein, soy protein, gelatin, starch, styrene-butadiene latex and acrylic emulsion. Other additives include ink fixing agents, water resistance agents, dot adjusters, wetting agents, pH adjusters, fluorescent brighteners, antioxidants, UV absorbers, preservatives, antifoaming agents, thickeners, pigments Examples thereof include a dispersant and a release agent.
[0106]
There is no restriction | limiting in particular as a means to apply | coat the chemical | medical agent for inkjet recording sheets of this invention on a base material, According to the objective, it can select suitably. Various known methods such as blade coater, roll coater, air knife coater, bar coater, curtain coater, spray coater, size press, impregnation and the like are used. If necessary, smoothing can be performed by a smoothing device such as a super calendar or a soft calendar. The coating layer may have a laminated structure of two or more layers according to the use and purpose. Although there is no restriction | limiting in particular about the application quantity of a coating layer, 3-30 g / m in solid content of a composite_body | complex.²Is preferred. 30g / m²Even if it is applied more, the properties do not improve further, and 3 g / m²If it is less, the ink absorbability may be insufficient.
[0107]
The water-soluble or water-dispersible polymer compound / calcium phosphate complex containing a carboxyl group of the present invention can contain calcium phosphate having a high degree of transparency and a high affinity for an organism / biological body in a wide ratio. Because of its characteristics, in addition to the above, paint, adhesive, pigment binder, ceramic binder, warp agent, emulsifier, chromatography filler, filter material, resin modifier, wastewater treatment agent, antibacterial agent, difficulty It can be used in a wide range of fields such as a fuel, a sensor material such as humidity and carbon dioxide, a cell culture substrate, a separation membrane, and a food additive.
[0108]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Moreover,% used in the following examples indicates a weight basis unless otherwise specified.
The viscosity is a value measured at 25 ° C. with a B-type viscometer [manufactured by Tokimec Co., Ltd.].
Analysis by X-ray diffraction was performed using a RINT X-ray Diffractometer (manufactured by Rigaku Corporation).
FT-IR measurement was performed using a FT / IR-8300 Fourier transform infrared spectrophotometer manufactured by JASCO Corporation.
The light transmittance measurement was performed using a Shimadzu spectrophotometer UV-2200A (manufactured by Shimadzu Corporation).
Transmission electron microscope (TEM) observation was performed using an H-300 type Hitachi electron microscope (manufactured by Hitachi, Ltd.) and a JEM-2010 type transmission electron microscope (manufactured by JEOL Ltd.).
The ultra-micro hardness measurement was performed using a Shimadzu dynamic ultra-micro hardness meter DUH-201 (manufactured by Shimadzu Corporation).
[0109]
[Polymer Production Example 1]
Mix and dissolve 30.00 g of acrylamide, 0.15 g of sodium hypophosphite monohydrate and 266.85 g of distilled water in a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet tube, and adjust the pH to 4.5. It was adjusted. The temperature of the solution was adjusted to 80 ° C. while flowing nitrogen gas from above the liquid surface at a constant flow rate, and then 3.0 g of an aqueous solution in which 0.30 g of ammonium persulfate was dissolved was added, and a polymerization reaction was performed for 3 hours. The reaction was terminated by cooling to 30 ° C. or lower to obtain a (meth) acrylamide polymer (polymer A) aqueous solution (nonvolatile content: 11.12%) having a Brookfield viscosity of 114.4 mPa · s at 25 ° C.
The weight average molecular weight was 337,000.
[0110]
[Polymer Production Examples 2 to 5]
A reaction is carried out in the same manner as in Polymer Production Example 1 using acrylamide, a copolymerization monomer, a polymerization initiator, a chain transfer agent and the like described in Table 1, and a (meth) acrylamide polymer (polymers B to E). An aqueous solution was obtained.
The polymerization results are shown in Table 1.
[0111]
[Polymer Production Example 6]
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen gas inlet tube, 30.00 g of N, N-dimethylacrylamide (DMA), 0.15 g of sodium hypophosphite monohydrate and 266.85 g of distilled water were added. The mixture was dissolved and the pH was adjusted to 4.5. The temperature of the solution was adjusted to 80 ° C. while flowing nitrogen gas from above the liquid surface at a constant flow rate, and then 3.0 g of an aqueous solution in which 0.30 g of ammonium persulfate was dissolved was added, and a polymerization reaction was performed for 3 hours. The reaction was terminated by cooling to 30 ° C. or lower to obtain a (meth) acrylamide polymer (polymer F) aqueous solution (nonvolatile content: 10.58%) having a Brookfield viscosity of 37.5 mPa · s at 25 ° C.
The weight average molecular weight was 232,200.
[0112]
[Polymer Production Examples 7 to 20]
The reaction is carried out in the same manner as in Polymer Production Example 6 using the amounts of DMA, copolymerization monomer, polymerization initiator, chain transfer agent and the like listed in Table 1, and (meth) acrylamide polymers (polymers G to P: Those having the same composition were distinguished by subscripts such as (1).
The polymerization results are shown in Table 1.
[0113]
[Polymer Production Example 21]
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet tube, 22.12 g of N-vinyl-2-pyrrolidone (NVP), 2.88 g of itaconic acid, 0.13 g of sodium hypophosphite monohydrate Then, 218.84 g of distilled water was mixed and dissolved, and the pH was adjusted to 4.5. After adjusting the temperature of the solution to 80 ° C. while flowing nitrogen gas from the upper part of the liquid surface at a constant flow rate, 0.25 g of 4,4′-azobis (2-cyanovaleric acid) (V-501: Wako Pure Chemical Industries, Ltd.) was added. 2.5 g of the dissolved aqueous solution was added and the polymerization reaction was carried out for 3 hours. The reaction was terminated by cooling to 30 ° C. or lower to obtain a vinylpyrrolidone polymer (polymer R) aqueous solution (nonvolatile content: 11.28%) having a Brookfield viscosity of 54.5 mPa · s at 25 ° C.
The weight average molecular weight was 251,000.
[0114]
[Polymer Production Examples 22-24]
NVP, a copolymerization monomer, a polymerization initiator, a chain transfer agent, etc. are reacted in the same manner as in Polymer Production Example 21 using the amounts described in Table 2 to obtain a vinylpyrrolidone polymer (polymers S to U). It was.
The polymerization results are shown in Table 2.
[0115]
[Polymer Production Comparative Example 1]
N-vinyl-2-pyrrolidone (NVP) 30.00 g and distilled water 268.50 g were mixed and dissolved in a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet tube, and the pH was adjusted to 4.5. After adjusting the temperature of the solution to 80 ° C. while flowing nitrogen gas at a constant flow rate from the top of the liquid surface, 2,2′-azobis (2-amidinopropane) dihydrochloride (V-50: manufactured by Wako Pure Chemical Industries) 0.15 1.5 g of an aqueous solution in which g was dissolved was added, and a polymerization reaction was carried out for 3 hours. The reaction was terminated by cooling to 30 ° C. or lower to obtain an aqueous vinylpyrrolidone polymer (polymer V) aqueous solution (nonvolatile content: 10.57%) having a Brookfield viscosity of 36.0 mPa · s at 25 ° C.
The weight average molecular weight was 149,800.
[0116]
[Polymer Production Comparative Examples 2 to 4]
NVP, a copolymerization monomer, a polymerization initiator, a chain transfer agent, etc. are reacted in the same manner as in Polymer Production Comparative Example 1 using the amounts described in Table 2, and a vinylpyrrolidone polymer (polymers W to Y) is obtained. Obtained.
The polymerization results are shown in Table 2.
[0117]
[Composite example]
The complexing of the polymer and calcium phosphate is shown in the complexing examples below.
A method of feeding a mixed solution of a polymer and phosphoric acid to a calcium hydroxide suspension is represented as I, and a method of feeding phosphoric acid to a mixed suspension of calcium hydroxide and a polymer is represented as II. Indicated.
[0118]
The stability of the obtained organic polymer / calcium phosphate fine particle dispersion solution was determined by visually confirming the dispersion state after standing for 1 day after production (stationary dispersibility), and centrifuged at 2,000 rpm for 10 minutes. A method of visually confirming the dispersion state after the treatment (centrifugal dispersibility) was evaluated in 5 stages of 1 to 5, respectively.
1: No separation
2: No separation, with very small initial sediment
3: Separation supernatant <10%
4: Separation supernatant 10-25%
5: Separation supernatant> 25%
In addition, 2 is a very small amount, and precipitates are observed after being left overnight for production. By performing filtration treatment as necessary, the dispersion aqueous solution of the present invention is obtained. 1 and 2 are regions included in the stable dispersion of the present invention.
[0119]
<Composite with (meth) acrylamide polymer (1)>
[Composite Example 1]
A round bottom separable flask equipped with a stirrer and a thermometer was charged with 4.61 g of calcium hydroxide and 145.39 g of distilled water, and stirred vigorously to obtain a suspension. The water-soluble polymer (Polymer A) obtained in Polymer Production Example 1 was prepared by adjusting the temperature of the suspension to 40 ° C. and stirring at a stirring speed of 200 rpm while adjusting 33.01 g of 11.1% phosphoric acid aqueous solution and pH to 10.0. ) An aqueous solution prepared by mixing and dissolving 56.21 g of aqueous solution and 10.78 g of distilled water was continuously added over 2 hours using a microtube pump (Reaction Method I). After the addition, the reaction is further carried out at 40 ° C. for 1 hour, and separation is not caused even if left for one day, and the (meth) acrylamide polymer / calcium phosphate fine particles (50:50) dispersion aqueous solution (a-1 )
The pH of the obtained dispersion aqueous solution was 8.75, and almost no precipitate was observed. Even when left at room temperature for several weeks, it was stable without causing changes such as separation and sedimentation. Furthermore, the obtained fine particle dispersion was centrifuged at 2,000 rpm for 10 minutes, but no changes such as separation and sedimentation were observed.
[0120]
[Composite Examples 2-33]
Using various (meth) acrylamide polymers BP described in Table 3, the reaction was performed in the same manner as in Example 1 under the conditions shown in Table 3 to obtain fine particle dispersed aqueous solutions b-1 to p-1. .
The compounding ratio, charge amount, reaction conditions, reaction method, and reaction results are shown in Table 3.
In methods I and II, the aqueous polymer solution was previously adjusted to pH 10.0 and then mixed with phosphoric acid or calcium hydroxide. The amount of feed liquid was 40% of the total reaction liquid as a standard.
In addition, the compounding example was based on a reaction concentration (solid content) of 5% and a reaction temperature of 40 ° C. as standard, but the reaction concentration was increased to 10% (combining examples 10 and 11), and the reaction temperature was 20−. Also in the examples set at 80 ° C. (compositing examples 13 to 16), it was shown that the composite can be performed without any problem.
Polymers A, C, D, E, and F are polymers that do not contain a carboxyl group in the copolymerization monomer, but acrylamide or N, N-dimethylacrylamide amide, which is the main polymer component in the complexing reaction process. Since the bond has undergone a hydrolysis reaction with alkali (calcium hydroxide) to generate a carboxyl group (detects ammonia and dimethylamine generated by the hydrolysis reaction), and as a result, the composite is good is there.
[0121]
<Composite with (meth) acrylamide polymer (2)>
[Composite Examples 34 to 38]
Using carboxyl group-containing polyacrylamide (Hopron-3150B, manufactured by Mitsui Chemicals), the reaction was performed in the same manner as in Example 1 under the conditions shown in Table 4 to obtain fine particle dispersed aqueous solutions q-1 to q-5.
The composite ratio, the charged amount, the reaction conditions, the reaction method, and the reaction results are shown in Table 4.
[0122]
<Composite with vinylpyrrolidone polymer>
[Composite Examples 39 to 42]
Using the vinylpyrrolidone polymers R to U shown in Table 2, the reaction was performed in the same manner as in Example 1 under the conditions shown in Table 4 to obtain fine particle dispersed aqueous solutions r-1 to u-1.
The composite ratio, the charged amount, the reaction conditions, the reaction method, and the reaction results are shown in Table 4.
[0123]
[Composite Comparative Examples 1 to 5]
Using a blank to which no polymer was added (Comparative Example 1) and the water-soluble polymers V to Y described in Table 2, the reaction was performed in the same manner as in Example 1 under the conditions shown in Table 4, but both When the stirring was stopped and the mixture was allowed to stand, it immediately settled and separated.
Table 4 shows the composite ratio, the charged amount, the reaction conditions, the reaction method, and the reaction results.
[0124]
As is clear from the comparison between Composite Examples 39 to 42 and Composite Comparative Examples 1 to 5, in the case of vinylpyrrolidone-based polymers, the copolymer component having a carboxyl group makes a stable composite dispersion. It can be seen that it is necessary. N-vinyl-2-pyrrolidone which is the main component of the polymer is not subjected to hydrolysis reaction with alkali under the complexing condition of the present invention, and does not generate a carboxyl group even in the complexing reaction process. In that respect, it is different from the amide-based polymer described above, and therefore, if a copolymer containing no carboxyl group is used as in the comparative example, a stable dispersion solution cannot be obtained.
[0125]
<Example of compounding with carboxyl group-modified PVA>
[Composite Example 43]
Carboxyl group-modified polyvinyl alcohol (PVA KM-118; Kuraray Co., Ltd., saponification degree 97.4 mol%, polymerization degree 1,800 previously dissolved in distilled water in a round bottom separable flask equipped with a stirrer and a thermometer ) 127.01 g of aqueous solution (9.35%) and 20.91 g of distilled water were added, 1.62 g of 10% sodium hydroxide was added, and then 0.461 g of calcium hydroxide was added with stirring to form a suspension. Adjust the temperature of the suspension to 40 ° C and stir at a stirring speed of 200rpm while continuously stirring the aqueous solution in which 3.50g of 10.5% phosphoric acid aqueous solution and 96.50g of distilled water were mixed and dissolved using a microtube pump for 2 hours. Added. After addition, the reaction was further carried out at 40 ° C. for 2 hours to obtain a carboxyl group-modified polyvinyl alcohol / calcium phosphate fine particle (95: 5) dispersion aqueous solution (z-1). The pH of the obtained dispersion aqueous solution was 6.55, and almost no precipitate was observed, and it was stable without causing changes such as separation and sedimentation even after standing for several weeks. Furthermore, the obtained fine particle dispersion was centrifuged at 2,000 rpm for 10 minutes, but no changes such as separation and sedimentation were observed. The solid content concentration of the reaction solution was 5.2%.
[0126]
[Composite Examples 44 to 66]
Using carboxyl group-modified polyvinyl alcohol (Z1 to Z13), the reaction was performed in the same manner as in Composite Example 43 under the conditions shown in Table 5.
Table 5 shows the composite ratio, the charged amount, the reaction conditions, the reaction method, and the reaction results.
The carboxyl group-modified polyvinyl alcohol used for the composite was Z1: KM-118 (saponification degree 97.4 mol%), Z2: KM-618 (saponification degree 93.7 mol%), Z3: KL-118 (saponification degree 97.4). Mol%) (Z3 ′ is previously hydrolyzed with an unsaponified amount of NaOH), Z4: K-5112 (degree of saponification 95.1 mol%), Z5: SK-5102 (degree of saponification 97.6 mol%) (above Kuraray), Z6: UFA170 (degree of saponification> 96.5 mol%), Z7: UFA170M (degree of saponification 92-95 mol%), Z8: UPA170 (degree of saponification 88-92 mol%) (above made by Unitika) ), Z9: T-330H (degree of saponification> 99.0 mol%), Z10: T-330 (degree of saponification 95.0-98.0 mol%), Z11: T-350 (degree of saponification 93.0-95.0 mol%), Z12 : T-230 (degree of saponification 95.0-98.0 mol %), Z13: T-215 (degree of saponification 95.0-98.0 mol%) (manufactured by Nippon Synthetic Chemical Co., Ltd.).
[0127]
[Composite Comparison Example 6]
High purity polyvinyl alcohol (PVA 103C; Kuraray Co., Ltd., saponification degree 98.6 mol%, polymerization degree 300) aqueous solution previously dissolved in distilled water in a round bottom separable flask equipped with a stirrer and a thermometer (10.0%) 62.50 g and distilled water 82.89 g were added, 0.05% of 10% sodium hydroxide was added, and then 4.61 g of calcium hydroxide was added with stirring to form a suspension. Adjust the temperature of the suspension to 40 ° C and stir at a stirring speed of 200 rpm while continuously stirring the aqueous solution in which 34.97 g of 10.5% phosphoric acid aqueous solution and 65.03 g of distilled water are mixed and dissolved using a microtube pump for 2 hours. Added. After the addition, the reaction was further carried out at 40 ° C. for 2 hours to obtain a polyvinyl alcohol / calcium phosphate fine particle (50:50) dispersion aqueous solution (Z14-1).
The pH of the obtained aqueous dispersion was 7.61, and when it was allowed to stand overnight, about 20% of the reaction solution was separated as a transparent supernatant (still dispersibility 4). The solid content concentration of the reaction solution was 5.0%.
[0128]
[Composite Comparative Examples 7 to 11]
Various polyvinyl alcohols Z14-Z16 were used and the reaction was carried out in the same manner as in Comparative Example 6 under the conditions shown in Table 5; Table 5 shows the composite ratio, the charged amount, the reaction conditions, the reaction method, and the reaction results.
Polyvinyl alcohol used for the composite was Z14: 103C (high purity polyvinyl alcohol, saponification degree 98.6 mol%), Z15: 205C (high purity polyvinyl alcohol, saponification degree 88.1 mol%), Z16: CM-318 (cation) Polyvinyl alcohol, saponification degree 96.4 mol%), Z17: 205S (partially saponified polyvinyl alcohol, saponification degree 88.0 mol%) (Z14 'and 16' are previously hydrolyzed with an unsaponifiable equivalent of NaOH) (Made by Kuraray Co., Ltd.)
[0129]
As is clear from the composite comparative examples 6 to 11, PVA having no carboxyl group in the molecule does not provide a stable fine particle dispersed aqueous solution. In Comparative Comparative Examples 7 and 10, the complete saponification treatment was performed and the influence of the unsaponified portion was eliminated. However, the complexation was still poor, and the effect of the carboxyl group on the complexation is clear.
[0130]
[Stability of composite dispersed aqueous solution]
(1) pH effect
Distilled water was added to the dispersion aqueous solution (h-3) obtained in the composite example 10 and diluted to adjust the concentration to 0.5 wt%. To this dispersion, about 30 ml, an 11.1 wt% aqueous phosphoric acid solution was added little by little with a microsyringe to adjust the pH to 6.51, 5.93, 5.52, 5.01. No change was observed immediately after the addition, but those adjusted to pH 5.01 were completely separated into two layers when left overnight. As for other things, the visual change was not recognized.
Further, when 11.1 wt% phosphoric acid was continuously added to the 0.5 wt% diluted solution, phosphoric acid was consumed around pH 4.5, and the cloudy aqueous dispersion solution became completely transparent. The pH region causing the two-phase separation is the pKa region of the carboxyl group of the polymer, and the carboxylic acid anion loses ionicity partially or entirely as the pH is lowered, which improves the stability of the composite dispersion. It is thought to have an influence. When the pH is further lowered, the complex disappears with the dissolution of the hydroxyapatite, so that it becomes transparent.
[0131]
(2) Inorganic salt addition effect
In the same manner as in (1), the concentration of the aqueous dispersion obtained in Example 10 was adjusted to 0.5 wt%. At this time, NaCl, Na so that the salt concentration is 0.05 to 2.0 mol / l.₂SO_FourWas added to evaluate the stability of the dispersion.
In this concentration range, no change due to the addition of NaCl was observed.₂SO_FourThe added system was completely separated into two layers at a concentration of 0.25 mol / l or more, and there was no change after one month at a concentration of 0.05 mol / l.
The above pH and salt addition effects indicate that an ionic action plays an important role in dispersion stabilization, and it was strongly suggested that this is an action caused by a carboxylate anion.
[0132]
[Electron microscope observation / dispersion]
・ Poly (meth) acrylamide (PAM) complex
FIG. 1 shows a transmission electron micrograph obtained by diluting the (meth) acrylamide polymer / calcium phosphate fine particle dispersion aqueous solution (h-2) obtained in Example 9 and drying on a collodion film-clad copper mesh. Shown in (a).
As is clear from FIG. 1 (a), the calcium phosphate fine particles are elongated and elliptical particles, and these primary particles are uniformly dispersed on the collodion film without agglomeration. The particle size distribution in the major axis direction obtained from FIG. 1 is shown in FIG.
[0133]
・ Carboxyl group-modified PVA composite
A transmission electron micrograph taken by diluting the carboxyl group-modified polyvinyl alcohol / calcium phosphate fine particle-dispersed aqueous solution (z1-8) obtained in Example 50 and drying on a collodion film-clad copper mesh is shown in FIG. )Pointing out toungue.
In FIG. 1 (b), as in FIG. 1 (a), the calcium phosphate fine particles are elongated and elliptical particles, and these primary particles are uniformly dispersed on the collodion film without agglomeration.
[0134]
·blank
Since the blank calcium phosphate dispersion aqueous solution (blank) obtained in the composite comparative example 1 is settled and separated, it is diluted after sampling with sufficient agitation and dried on a collodion film-clad copper mesh. The obtained transmission electron micrograph is shown in FIG.
When FIG. 2 is seen, it has the structure where many elongate acicular crystals aggregated, and it turns out that it is remarkably different from FIG. 1 (a), (b) which is a stable dispersion aqueous solution.
[0135]
[Create film]
[Film creation example 1]
By putting the stable dispersion aqueous solution (a-1 to z13-1) obtained in the composite examples 1 to 66 into a petri dish made of polymethylpentene resin having a diameter of 90 mm and placing it on a horizontal table and flowing dry nitrogen A carboxyl group-containing polymer / calcium phosphate composite film having excellent transparency was produced. All samples became transparent films. Further, no change was observed in the transparency of the film that was dried for 2 hours with a blow dryer at 110 ° C.
Films with various thicknesses were prepared by adjusting the amount of liquid to be placed in the petri dish. In particular, the film prepared from the PVA-based composite dispersion aqueous solution (z1-1 to z13-1) obtained in the composite examples 43 to 66 was a tough and flexible film, and had a cutting processability with scissors. Furthermore, by adding 10%, 20% or 30% glycerin as a plasticizer to these dispersions as a plasticizer, even a film completely dried in a composite containing 50% calcium phosphate is flexible. It is so rich that it won't break even when bent.
Since the dispersed aqueous solutions (v-1 to y-1, z14-1 to z16-2) obtained in the composite comparative examples 2 to 10 are settled and separated, a polymethylpentene resin having a diameter of 90 mm after well stirring I tried to produce a polyvinyl alcohol / calcium phosphate composite film containing no carboxyl groups by putting it in a petri dish and flowing it on a horizontal table, but completely separated into a transparent polymer film and a white solid, It did not result in a uniform composite film.
[0136]
[Example 2 for creating a film]
If necessary, the stable dispersion aqueous solution (a-1 to z13-1) obtained in the composite examples 1 to 66, which was filtered with a filter cloth or a metal mesh, was placed on a polyethylene terephthalate (PET) film. A film having a surface layer of a carboxyl group-containing polymer / calcium phosphate composite having excellent transparency was prepared by coating with a coater, fixing the film and air drying.
[0137]
[Example 3 of film creation]
If necessary, the stable dispersed aqueous solution (a-1 to z13-1) obtained in Composite Examples 1 to 66, which has been filtered with a filter cloth or a metal mesh, is flow-coated on glass, on a horizontal platform. A glass plate having a surface layer of a carboxyl group-containing polymer / calcium phosphate composite film excellent in transparency was produced by flowing dry nitrogen over the surface.
[0138]
[Film tensile strength measurement]
・ Carboxyl group-modified PVA composite
The film having an average film thickness of 64 μm obtained in Film Preparation Example 1 from the dispersion aqueous solution (z1-9) (polymer: calcium phosphate = 50: 50 composite) obtained in Composite Example 51 and used for composite Each sample was conditioned for one week under conditions of 23 ± 2 ° C. and 50 ± 5% RH using a film having an average film thickness of 75 μm formed from the aqueous solution of the raw material PVA (Z1: KM-118) by the same method. Was subjected to a tensile test at a speed of 50.0 mm / min using a test piece of JIS K7113 2 (1/2) type.
Compared to the tensile strength (breaking) of 65.3 MPa in the PVA single system, the composite film had a tensile strength of 116.8 MPa, indicating an improvement in strength of about 80%.
[0139]
(Ultra-micro hardness measurement)
・ Carboxyl group-modified PVA composite
Example 1 of film production from dispersion aqueous solution (z1-9) of composite example 51 (polymer: calcium phosphate = 50: 50 composite) using dynamic ultra-small hardness meter DUH-201 (manufactured by Shimadzu Corporation) And the film of the raw material PVA (Z1: KM-118) used for the composite was measured. Each film thickness is the same as the film used in the tensile test. Tested in No-2 mode for samples conditioned at 23 ± 2 ℃ and 50 ± 5% RH for 1 week. The test was performed under the conditions of a load of 9.8 mN, a holding time of 5 seconds, a load speed of 1.428 mN / sec, and a displacement full scale of 10 μm.
The indentation depth (D1, D2 (μm)) when holding 9.8mN for 5 seconds and after unloading is the average value measured at 10 points, 1.42 and 1.04 for the PVA single system, and 1.06 and 0.77 for the composite system, respectively. there were. The dynamic hardness (DHT115-1 and DHT115-2) calculated from these values is 19.0 and 35.4 for the PVA single system, respectively, and 33.8 and 65.2 for the composite system. understood.
The dynamic hardness is calculated from the following calculation formula. When a triangular pyramid indenter (115 °) is used, α = 3.8584.
Dynamic hardness = {9.8 (mN) / D2} × α
[0140]
[Gas permeability]
The film obtained in Film Preparation Example 1 from the aqueous dispersion (z1-9) of the composite example 51 (polymer: calcium phosphate = 50: 50 composite) and the raw material PVA used for the composite (Z1: KM-118) ) The film transmittance of helium gas was measured for a single film. The transmittance measurement was performed using a film gas permeability measuring device disclosed in Japanese Patent Application Laid-Open No. 6-241978 using a quadrupole mass spectrometer as a detector. The thickness of PVC single film is 82μm, and the permeation rate of helium gas is 10.7cc / m.²・ Day (Transmission coefficient: 13.3 * 10-¹³cc * cm / cm²・ For sec · cmHg), the composite film thickness is 55μm and the permeation rate is 7.5cc / m.²・ Day (Transmission coefficient: 6.3 * 10-¹³cc * cm / cm²· Sec · cmHg). It was confirmed that the gas permeability was greatly improved by combining with a compound having a permeability coefficient of 50% or less.
[0141]
[FT-IR measurement]
・ PAM complex
FIG. 4A shows an FT-IR spectrum of a sample obtained by casting the dispersion aqueous solution (h-5) produced in Composite Example 12 onto a KRS-5 window plate to form a thin film.
Both a peak derived from a (meth) acrylamide polymer and a peak derived from hydroxyapatite were observed.
Moreover, when this film was heat-treated at 800 ° C. for 3 hours in an electric furnace, a white solid remained, and its weight was 50% before the heat treatment. The IR spectrum of the white solid is shown in FIG. It was confirmed that the polymer component was burned out by the heat treatment, and the hydroxyapatite that had been crystallized remained quantitatively.
[0142]
・ Carboxyl group-modified PVA composite
FIG. 5 (a) shows an FT-IR spectrum of a sample obtained by casting the dispersion aqueous solution (z1-7) produced in Composite Example 49 on a KRS-5 window plate to form a thin film.
Both a peak derived from carboxyl group-modified polyvinyl alcohol and a peak derived from hydroxyapatite were observed.
Moreover, when this film was heat-treated at 800 ° C. for 9 hours in an electric furnace, a white solid remained and its weight was 50% before the heat treatment. FIG. 5B shows an FT-IR spectrum obtained by measuring the white solid by the KBr tablet method. It was confirmed that the polymer component was burned out by the heat treatment, and the hydroxyapatite that had been crystallized remained quantitatively.
[0143]
・ Polyvinylpyrrolidone complex
FIG. 6 shows an FT-IR spectrum of a sample obtained by casting the dispersion aqueous solution (u-1) produced in Composite Example 42 onto a KRS-5 window plate to form a thin film.
Both a peak derived from a vinylpyrrolidone polymer and a peak derived from hydroxyapatite were observed.
[0144]
[X-ray diffraction analysis (XRD)]
・ PAM complex
The XRD spectrum of the sample obtained by lyophilizing the dispersion aqueous solution (h-5) produced in the composite example 12 is shown in FIG. 7 (a), and the same dispersion aqueous solution is prepared by the method shown in film production example 3. An XRD spectrum of a sample cast on a substrate to form a film is shown in FIG. A peak corresponding to the (h, k, 0) plane is marked with *.
Although the spectrum pattern of the powder was consistent with hydroxyapatite, the film spectrum shows a peak on the (h, k, 0) plane, but the other peaks are greatly reduced in intensity or disappeared. The hydroxyapatite particles in the film are presumed to have the c-axis oriented parallel to the glass surface.
[0145]
・ Carboxyl group-modified PVA composite
The spectral pattern of the XRD spectrum of the sample obtained by lyophilizing the dispersion aqueous solution (z1-7) produced in the complex production example 49 substantially coincided with hydroxyapatite (FIG. 8 (a)). Although the peak of (h, k, 0) plane of hydroxyapatite was observed, the intensity of other peaks was greatly reduced or disappeared. FIG. 8 (a) shows an XRD spectrum of a sample obtained by casting the same aqueous dispersion on a glass substrate to form a film. Similar to the complex with the (meth) acrylamide polymer, it was assumed that the hydroxyapatite particles in the film had the c-axis oriented parallel to the glass surface.
[0146]
[Electron microscope observation / film]
・ PAM complex
A composite film (film production example 1) produced by the casting method from the (meth) acrylamide polymer / calcium phosphate fine particle dispersion aqueous solution (h-5) obtained in the composite example 12 was prepared by an ultrathin section method. It observed with the transmission electron microscope (TEM) from the plane direction and the cross-sectional direction. The result in the plane direction is shown in FIG. 9 (a), and the result in the cross-sectional direction is shown in FIG. 9 (b).
In the planar direction (a), elongated elliptical particles having a major axis of about 70 to 200 nm and a minor axis of about 25 to 50 nm were observed. On the other hand, in the cross-sectional direction (b), many images of the elongated particles were observed, and some of them showed a hollow structure. An electron microscopic image showing that the major axis is oriented in the plane direction agrees well with the result of XRD. As a result of local elemental analysis of particles by an ultra thin window (UTW) type EDS detector (Energy Dispersive Spectroscopy), the element ratio of Ca / P showed a value of 1.43 as an average of three points. . Since the Ca / P ratio of hydroxyapatite was 1.67, it was shown from the results of XRD, IR, and TEM that the calcium phosphate particles in the film were calcium-deficient hydroxyapatite.
[0147]
[Film light transmittance measurement]
・ PAM complex
Wavelength dependence of light transmittance of a composite film (average film thickness was in the range of 230 μm to 270 μm) made from the dispersions a-1 to u-1 having excellent stability by the method of Film Preparation Example 1 The properties showed similar patterns, and the transmittance at 700 nm exceeded 50%, indicating high transparency. FIG. 10 shows a comparison between the polymer / calcium phosphate composite film and the polymer single film among them.
As is clear from FIG. 10, the composite film had better transparency than the polymer single film.
Further, the effect of the compounding temperature on the transparency is shown in FIG. 11 [Film prepared from dispersed aqueous solution h-7 (composite temperature: 40 ° C.), film prepared from dispersed aqueous solution h-8 (composite temperature 60 ° C), a film prepared from the dispersed aqueous solution h-9 (composite temperature 80 ° C)]. From FIG. 11, it was found that the transparency of the film changes depending on the compounding temperature.
[0148]
The influence of the amount of water contained in the film is shown in FIG. The composite film prepared from the dispersed aqueous solution h-7 was immersed in water and then air-dried to change the water content. Films having a water content of 3%, 50%, 65%, 85% and 122%, respectively, with respect to the film weight were measured. In addition, what dried the film for 4 hours at 120 degreeC was made into the moisture content 0%. FIG. 12 shows that the transparency changes depending on the amount of water in the film, and this change was reversible. This phenomenon has a large change width especially in the ultraviolet light region, which indicates that it can be used for UV light-shielding cosmetics.
[0149]
・ Carboxyl group-modified PVA composite
The wavelength dependence of the light transmittance of the composite film produced by the method of Film Preparation Example 1 from the fine particle dispersion aqueous solution (z1-1 to z13-1) excellent in stability shows a similar pattern, both at 700 nm. The transmittance of was over 50%, indicating high transparency. The film used for the measurement has an average film thickness in the range of 90 μm to 150 μm, and a film is prepared from the dispersed aqueous solutions z1-3 (90:10 complex) and z1-5 (70:30 complex) shown in FIG. The films produced in Example 1 were about 120 and 140 μm, respectively, and the films similarly produced from the aqueous dispersions z1-6 (60:40 composite) and z1-7 (50:50 composite) were about 90 μm. It was.
[0150]
[Paper coating test]
In the following coating examples and coating comparison examples, medium paper (basis weight: 58 g / m) is used as the base paper to be coated.²) Was used. The surface strength is RI-3 type (manufactured by Meisei Seisakusho Co., Ltd.) and RI pick is used (the surface strength is higher as the score is higher in the 10-point relative evaluation), and the Z-axis strength is the internal bond tester Measured by Kogyo Co., Ltd.).
[0151]
[Coating Examples 1 to 5]
The coated base paper is immersed for 1 second in the fine particle dispersion aqueous solution (q-1 to q-5) obtained in the composite examples 34 to 38, and the amount of liquid absorbed after squeezing with two rolls is weighed. The coating amount was determined. The coating amount is 1.0 and 1.8 g / m for the nonvolatile content of (meth) acrylamide polymer and calcium phosphate.²In advance, the concentration of the coating solution was adjusted (dispersed aqueous solution concentration: 2.0 to 3.5 wt%). The pH of the coating solution was adjusted to 7.8 to 8.2. Immediately after coating, the film was dried for 90 seconds with a drum dryer whose surface temperature was set to 110 ° C., and the paper strength after humidity adjustment for 24 hours was measured in a constant temperature and humidity chamber (20 ° C., 65% RH). The results are shown in Table 6.
[0152]
[Coating comparison example 1]
A coated paper is prepared by performing the same operations as in Coating Examples 1 to 5 except that the coating solution is changed to a single aqueous solution of a (meth) acrylamide polymer (Hopron 3150B; manufactured by Mitsui Chemicals). The force intensity was measured.
The results are shown in Table 6.
[0153]
From the results shown in Table 6, it is clear that the paper strength improving ability of the aqueous dispersion is extremely superior to that of the conventional (meth) acrylamide polymer. In particular, in a dispersion having a (meth) acrylamide polymer / calcium phosphate ratio of 95/5, the Z-axis strength improvement rate from the base paper to be coated, which is a blank, is increased by 20 to 35% relative to the coating comparative example 1. And gives very good results compared to the case of using the polymer alone. These results mean that the limit of the paper strength that can be reached by the polymer alone can be further increased by dispersing calcium phosphate fine particles and compositing with the polymer.
[0154]
[Inkjet (IJ) coating test]
In the following coating examples and coating comparative examples, high-quality paper (OK-Prince, basis weight 104.7 g / m)²: Oji Paper Co., Ltd.).
[0155]
[IJ Coating Example 1]
After adjusting the (meth) acrylamide polymer / calcium phosphate fine particle dispersed aqueous solution (h-4) obtained in Example 11 to 10%, the coating amount was 5.0 g / m on the base paper to be coated.²It coated with the wire bar so that it might become. After coating, it was dried at 120 ° C. for 90 seconds to obtain an ink jet recording sheet.
[0156]
[IJ Coating Comparative Example 1]
10% dispersion obtained by stirring 10 parts of fine powder hydroxyapatite (HCA-3000: manufactured by Mitsui Chemicals, Inc.) and 90 parts of water at 3000 rpm for 3 minutes using a homogenizer (manufactured by Nippon Seiki Seisakusho) The aqueous polymer A solution obtained in the polymer production example adjusted to 10% was mixed at 1: 1 to obtain a coating solution. Dry coating amount of the obtained coating liquid on the base paper to be coated is 5.0 g / m²After coating with a wire bar, it was dried at 120 ° C. for 90 seconds to obtain an ink jet recording sheet.
[0157]
[IJ Coating Comparative Example 2]
A 10% dispersion obtained by stirring 10 parts of fine powdered silica (Mizukasil P-78A: Mizusawa Chemical Co., Ltd.) and 90 parts of water using a homogenizer at 3000 rpm for 3 minutes and polyvinyl alcohol (PVA-117S). : 10% aqueous solution (manufactured by Kuraray Co., Ltd.) was mixed at a ratio of 1: 1 to obtain a coating solution. A coating amount of 5.0 g / m of the obtained coating liquid is applied onto the base paper to be coated²After coating with a wire bar, it was dried at 120 ° C. for 90 seconds to obtain an ink jet recording sheet.
[0158]
[IJ Coating Comparative Example 3]
An inkjet recording sheet was obtained in the same manner as in IJ Coating Comparative Example 2 except that polyvinyl alcohol was changed to polyvinyl pyrrolidone (K-90: manufactured by ISP).
[0159]
[IJ Coating Comparative Example 4]
An ink jet recording sheet was obtained in the same manner as in IJ Coating Comparative Example 2 except that the fine powder silica was changed to fine powder alumina (Cataloid AP-3: manufactured by Catalyst Chemicals Co., Ltd.).
[0160]
[IJ Coating Comparative Example 5]
Similar to IJ Coating Comparative Example 2 except that polyvinyl alcohol was changed to polyvinyl pyrrolidone (K-90: made by ISP) and fine powder silica was changed to fine powder alumina (Cataloid AP-3: made by Catalyst Chemicals Co., Ltd.). Thus, an inkjet recording sheet was obtained.
[0161]
The ink jet recording sheet prepared by the above method was examined for printability and yellowing resistance as follows.
About printability, it printed with the commercially available inkjet printer (PM-2000C: Seiko Epson Co., Ltd. product), and evaluated about printing density and dot shape (roundness).
The print density is measured by using a Macbeth densitometer (RD-918) to measure the black, cyan, magenta, and yellow solid portions. The print density is considerably high and excellent “」 ”, the print density is high“ ◯ ”, and the normal“ “Fair” and “x” having a low printing density were evaluated in four levels.
Dot shape (roundness) is magnified and observed with a magnifying glass, and by visual observation, excellent “◎” with high roundness, “Good” with good roundness, “△” with slight blurring, “X” with no roundness. The four grades were evaluated.
Table 7 shows the evaluation results.
[0162]
The yellowing resistance was evaluated as follows.
An adhesive tape (cello tape: manufactured by Nichiban Co., Ltd.) was affixed to the prepared inkjet recording sheet, and left at 20 ° C. for 4 weeks or at 40 ° C. for 2 weeks. Total color difference ΔE (ΔE = {(ΔL)) by measuring L, a, and b values with a spectral colorimeter (color guide: manufactured by Bic Gardner)²+ (△ a)²+ (△ b)²}^1/2), When the value of △ E is small and hardly yellowed, “◎”, as yellowing progresses and the value of △ E increases
A four-step evaluation was made with “◯”, “Δ”, and “×”.
[0163]
As shown in Table 7, it can be seen that the sheet coated with the (meth) acrylamide polymer / calcium phosphate fine particle dispersed aqueous solution does not turn yellow even when an adhesive tape is applied, and is excellent in yellowing resistance. Furthermore, it can be seen that the printing suitability is excellent because it is excellent in total balance.
[0164]
[Table 1]

[0165]
[Table 2]

[0166]
[Table 3]

[0167]
[Table 4]

[0168]
[Table 5]

[0169]
[Table 6]

[0170]
[Table 7]

[0171]
【The invention's effect】
INDUSTRIAL APPLICABILITY According to the present invention, a water-soluble or water-dispersible synthetic polymer compound / carboxyl group-containing aqueous solution containing a carboxyl group that is excellent in dispersion stability and can be used in various applications, and a water-soluble or water-dispersible synthesis containing a carboxyl group A polymer compound / inorganic fine particle composite can be provided.
The paper-making chemical comprising a water-soluble or water-dispersible synthetic polymer compound / inorganic fine particles containing a carboxyl group according to the present invention is further compared to a (meth) acrylamide polymer conventionally used as a paper strength enhancer. It is possible to provide a papermaking chemical having a high paper strength enhancing ability and a paper obtained using the papermaking chemical.
Furthermore, the ink jet recording chemicals comprising the water-soluble or water-dispersible synthetic polymer compound / inorganic fine particles containing a carboxyl group of the present invention are fine powder silica and fine powder alumina conventionally used as ink jet recording chemicals. Compared with the yellowing resistance of the coating layer, the ink jet recording sheet can be provided.
[Brief description of the drawings]
FIG. 1 (a) Transmission obtained by diluting a (meth) acrylamide polymer / calcium phosphate fine particle dispersion aqueous solution (h-2) obtained in Example 9 and drying on a collodion film-clad copper mesh. Type electron micrograph.
(B) Transmission electron micrograph obtained by diluting the carboxyl group-modified polyvinyl alcohol / calcium phosphate fine particle dispersion aqueous solution (z1-8) produced in Example 50 and drying on a collodion film-clad copper mesh.
FIG. 2 shows a transmission electron micrograph of the calcium phosphate fine particle dispersion prepared in Composite Comparative Example 1, diluted and dried on a collodion film-clad copper mesh.
3 is a particle size distribution diagram in the major axis direction obtained from FIG. 1 (a).
FIG. 4A is a diagram showing an FT-IR spectrum of a sample prepared by casting the PAM-based dispersion aqueous solution (h-5) produced in the composite example 12 onto a KRS-5 window plate to form a thin film.
(b) The figure which shows the FT-IR spectrum by the KBr tablet method of the white solid obtained by heat-treating this film at 800 degreeC for 3 hours in an electric furnace.
FIG. 5A is a diagram showing an FT-IR spectrum of a sample prepared by casting the carboxyl group-modified PVA-based aqueous dispersion (z1-7) produced in Example 49 into a window plate of KRS-5 to form a thin film.
(b) The figure which shows the FT-IR spectrum by the KBr tablet method of the white solid obtained by heat-processing this film for 9 hours at 800 degreeC in an electric furnace.
6 is a graph showing an FT-IR spectrum of a sample obtained by casting the polyvinyl pyrrolidone-based dispersion aqueous solution (u-1) produced in Composite Example 42 to a KRS-5 window plate to form a thin film. FIG.
FIG. 7 is a diagram showing an XRD spectrum of a sample obtained by lyophilizing a PAM-based dispersion aqueous solution (h-5) produced in Example 12 of complexing.
(b) Composite A diagram showing an XRD spectrum of a sample obtained by casting the PAM-based dispersion aqueous solution produced in Example 12 onto a glass substrate to form a film.
[* Is marked on the peak corresponding to the (h, k, 0) plane]
FIG. 8A is a diagram showing an XRD spectrum of a sample prepared by freeze-drying a carboxyl group-modified PVA-based dispersion aqueous solution (z1-7) produced in Example 49.
(b) Figure showing the XRD spectrum of a sample prepared by casting the carboxyl group-modified PVA-based dispersion aqueous solution produced in Example 49 on a glass substrate.
FIG. 9 shows the film direction of the film produced in Example 1 prepared from the (meth) acrylamide polymer / calcium phosphate fine particle dispersion aqueous solution (h-5) obtained in Composite Example 12 by the ultrathin section method. Transmission electron micrograph of (a) and cross-sectional direction (b)
FIG. 10 shows a film prepared in Example 1 from the (meth) acrylamide polymer / calcium phosphate fine particle dispersion aqueous solution (h-7) obtained in Compounding Example 14, and a (meth) acrylamide polymer H. The figure which shows the wavelength dependence of the light transmittance of the single film of (2)
FIG. 11 is a graph showing the wavelength dependence of the light transmittance of (meth) acrylamide polymer / calcium phosphate composite films having different conjugation temperatures.
[Film formed from dispersion aqueous solution h-7 (combination temperature: 40 ° C.), dispersion aqueous solution h-8 (combination temperature: 60 ° C.), dispersion aqueous solution h-9 (combination temperature: 80 ° C.)]
FIG. 12 is a graph showing the wavelength dependence of light transmittance of (meth) acrylamide polymer / calcium phosphate composite film (produced from dispersed aqueous solution h-7) having different water contents.
(Measured with respect to films having a water content of 3%, 50%, 65%, 85%, and 122%, respectively, with respect to the film weight. The film was dried at 120 ° C. for 4 hours to make the water content 0%. )
FIG. 13 shows the wavelength dependence of light transmittance of carboxyl group-modified PVA / calcium phosphate composite films (films obtained from dispersed aqueous solutions z1-3, z1-5, z1-6, z1-7) having different composite ratios. Illustration

Claims (13)

In the presence of a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, (a) one selected from Group 2 element compounds of the periodic table and (b) organic acids, inorganic acids and salts thereof The poorly water-soluble inorganic fine particles (B) having a particle diameter of 500 nm or less synthesized by reacting the above compounds are (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio). An organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability, characterized by containing. (B) The organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability according to claim 1, wherein the organic acid or inorganic acid is at least one acid selected from oxo acids and hydrohalic acids. (A) The organic polymer / inorganic fine particle-dispersed aqueous solution having excellent dispersion stability according to claim 1, wherein the group 2 element compound of the periodic table is a calcium compound. The organic polymer / inorganic fine particle dispersion aqueous solution having excellent dispersion stability according to claim 1, wherein the water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group is a polymer of an ethylenically unsaturated compound. The organic polymer / inorganic having excellent dispersion stability according to claim 4, wherein the polymer of the ethylenically unsaturated compound is any one of a (meth) acrylamide polymer, a carboxyl group-modified polyvinyl alcohol, and a vinylpyrrolidone polymer. A fine particle dispersed aqueous solution. The polymer of the ethylenically unsaturated compound is
(1) (meth) acrylamide polymer which is a polymer of 1 to 100% by weight of ethylenically unsaturated carboxylic acid amide compound and 0 to 99% by weight of copolymerizable ethylenically unsaturated compound,
(2) carboxyl group-modified polyvinyl alcohol produced by saponifying a polymer of ethylenically unsaturated carboxylic acid and vinyl acetate, and (3) N-vinyl-2-pyrrolidone 1-99.9. 5. The organic polymer having excellent dispersion stability according to claim 4, which is a vinylpyrrolidone polymer which is a polymer of 0.1% by weight and 0.1% by weight of a copolymerizable ethylenically unsaturated compound. / Inorganic fine particle dispersed aqueous solution. The organic polymer / inorganic fine particle dispersion aqueous solution excellent in dispersion stability according to any one of claims 4 to 6, wherein the poorly water-soluble inorganic fine particles (B) are calcium phosphate. In the presence of a water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, (a) one selected from Group 2 element compounds of the periodic table and (b) organic acids, inorganic acids and salts thereof A process for producing an organic polymer / inorganic fine particle dispersion aqueous solution excellent in dispersion stability, wherein the above-mentioned compound is reacted to produce poorly water-soluble inorganic fine particles (B) having a particle size of 500 nm or less. A water-soluble or water-dispersible synthetic polymer compound (A) containing a carboxyl group, obtained from the organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability according to any one of claims 1 to 7, and a particle size Organic polymer inorganic fine particle composite excellent in transparency containing 500 nm or less of poorly water-soluble inorganic fine particles (B) at (A) :( B) = 10: 90 to 99.99: 0.01 (weight ratio) . The organic polymer / inorganic fine particle composite having excellent transparency according to claim 9 , wherein the composite is a film having excellent transparency. A papermaking chemical obtained from the organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability according to any one of claims 1 to 7. The chemical | medical agent for inkjet recording sheets obtained from the organic polymer / inorganic fine particle dispersion | distribution aqueous solution excellent in the dispersion stability in any one of Claims 1-7. Cosmetics containing the organic polymer / inorganic fine particle-dispersed aqueous solution excellent in dispersion stability according to any one of claims 1 to 7.

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