JPH0753728A - Blocking-resistant synthetic resin emulsion powder - Google Patents
Blocking-resistant synthetic resin emulsion powderInfo
- Publication number
- JPH0753728A JPH0753728A JP23596993A JP23596993A JPH0753728A JP H0753728 A JPH0753728 A JP H0753728A JP 23596993 A JP23596993 A JP 23596993A JP 23596993 A JP23596993 A JP 23596993A JP H0753728 A JPH0753728 A JP H0753728A
- Authority
- JP
- Japan
- Prior art keywords
- emulsion
- particles
- synthetic resin
- powder
- dispersion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は粉末状のエマルジョンに
関する。該粉末状エマルジョンは耐ブロッキング性が優
れており、再乳化性も良好でセメント等の混和剤として
非常に有用である。
【０００２】
【従来の技術】合成樹脂エマルジョン粉末は、合成樹脂
水性エマルジョンに比べ、現場における調合が容易で取
扱性や作業性に優れていること、正確な調合が可能であ
ること、他の粉末と混合しやすいことなどの理由で、セ
メント系や石膏系組成物の混和剤、塗料あるいは、各種
接着剤の成分などとして用いられている。合成樹脂エマ
ルジョン粉末は、再乳化させ室温で使用するため合成樹
脂のガラス転移点が２０℃以下でなければならないが、
このような合成樹脂は軟らかいためエマルジョン粉末が
互いに粘結しやすい性質を有する。そのため合成樹脂エ
マルジョン粉末の製造時あるいは、貯蔵保管中に粉末粒
子同士が粘結しブロッキングしてしまうという問題があ
った。従来ブロッキングを防止する手段として、シリ
カ、炭酸カルシウム、珪酸アルミニウムなどの平均粒子
径０．０１〜０．５μｍの無機微粉末を合成樹脂エマル
ジョン粉末の製造時に添加することにより形成された合
成樹脂粉末粒子を無機微粉末で被覆する方法が知られて
いる。（特公昭５５−５０９７１、特公昭４６−１２９
０７）ところが、ブロッキング防止剤として無機微粉末
は、合成樹脂に対して３〜３０重量％もの多量を使用し
なければ充分な効果を得られず、多量の混入はセメント
系混和剤において、無機微粉末の吸水に起因する水／セ
メント比が増加し、最終強度がもとの合成樹脂水性エマ
ルジョンに比べ劣るという欠点があった。また、製造
時、具体的には、噴霧乾燥前後に無機微粒子で被覆する
場合、エマルジョン粒子を一次粒子の状態で被覆してい
ないため、特に粘結の著しい、ガラス転移点が−４０℃
以下の合成樹脂水性エマルジョンの粉末化は、ブロッキ
ングの問題により困難であった。（特開平４−２５５７
６０）
本発明者は、特開昭６２−２１３８３９号発明を完成
し、液状でエマルジョン粒子を無機粉末で被覆し無機粉
末とエマルジョンの均一な混合物を得、これにより、均
一な高分子物の分散液を提供した。
【０００３】
【発明が解決しようとする課題】本発明は必要最少量の
無機粉末で表面を被覆し、ブロッキングを防止するとと
もに再乳化したエマルジョンの性能を元のエマルジョン
とほぼ同様とすることの出来るエマルジョン粉末を提供
するものである。
【０００４】
【課題を解決した手段】本発明は、
「１． （Ａ）粒子表面に正または負の電荷を持たせた
合成樹脂水性エマルジョン粒子と（Ｂ）エマルジョン粒
子と反対の電荷を持たせたエマルジョン粒子の平均半径
の１／２以下の平均半径を有する、無機微粒子の分散液
を、次の式
（但し、ａはエマルジョン粒子の平均半径、ｂは無機粒
子の平均半径、Ｒは無機粉末の粒子数／エマルジョン粒
子数である。）を満足する比率で混合し、（Ｃ）該混合
物を噴霧乾燥して得た、エマルジョン粉末表面を無機粉
末で被った、耐ブロッキング性合成樹脂エマルジョン粉
末。
２． （Ａ）の電荷を持った合成樹脂エマルジョンが、
カチオン性またはアニオン性単量体、正または負の末端
を与える重合開始剤およびカチオン性またはアニオン性
の重合性乳化剤のいずれかから選んだ１または２以上を
用いて乳化重合して得た、エマルジョンである、１項に
記載された耐ブロッキング性合成樹脂エマルジョン粉
末。
３． カチオン性単量体またはアニオン性単量体を非イ
オン性単量体１００重量部に対し０．０１重量部以上使
用して乳化重合した、１項に記載された耐ブロッキング
性合成樹脂エマルジョン粉末。
４． 正または負の末端を与える重合開始剤を、重合性
単量体１００重量部に対して０．０１〜２０重量部用い
て乳化重合した、１項に記載された耐ブロッキング性合
成樹脂エマルジョン粉末。
５． （Ｂ）の電荷を持った無機粉微粒子が、水性分散
液に酸またはアルカリを加えｐＨを調整することにより
電荷を調整した無機粉末である、１項ないし４項のいず
れか１項に記載された耐ブロッキング性合成樹脂エマル
ジョン粉末。
６． 合成樹脂エマルジョンがガラス転移点２０℃以下
の合成樹脂エマルジョンである、１項ないし５項のいず
れか１項に記載された耐ブロッキング性合成樹脂エマル
ジョン粉末。」に関する。
【０００５】
【作用】本発明は、粉末粒子表面に均一に無機微粉末を
被覆した合成樹脂エマルジョン粉末に関するが、このよ
うなエマルジョン粉末に関する本発明にはいくつかの特
徴がある。
【０００６】本発明の第１の特徴は、粒子表面に電荷を
持たせた合成樹脂水性エマルジョンと、反対の電荷を持
った無機微粉末の水性分散液を混合して、エマルジョン
粒子表面に無機微粉末を電気的に吸着させて被覆するこ
とである。電気的に吸着させるので、無機粒子の付着し
ていない面に他の無機粒子が付着しエマルジョン粒子表
面に均一に無機粒子が被覆される。
【０００７】本発明の第２の特徴は、無機微粉末の粒子
の平均半径はエマルジョン粒子の平均半径の１／２以下
であることである。被覆されるエマルジョン粒子の半径
ａが被覆する無機粒子の半径ｂの２倍より大きいことが
必要である。両粒子の粒子径比ａ／ｂが２以内では、個
々のエマルジョン粒子が無機粒子で均一に被覆した複合
体は得られず、大きな凝集体を形成するためである。
【０００８】本発明の第３の特徴は、混合するエマルジ
ョン粒子と無機粒子の数の比率を特別の範囲としたこと
である。均一に被覆するための最も大切な要件は、無機
粒子とエマルジョン粒子の粒子数の比、すなわちシェル
形成用粒子の数をコア粒子の数で割った粒子数比（Ｒ）
が次式を満足することである。
（Ｒ）＞Ｎ×０．５
Ｎ：合成樹脂エマルジョン粒子１ケの表面を最密に被覆
するに要する無機粒子の数
【０００９】Ｐ：合成樹脂エマルジョン粒子１ケの表面
に、無機粒子が被覆したときの表面積＝半径（ａ＋ｂ）
の球面＝４π（ａ＋ｂ）２
このＰは、エマルジョン粒子の半径と被覆した無機粒子
の半径を加えた長さを半径とした球面表面積、つまりエ
マルジョン粒子表面に最密充填状態で被覆した無機粒子
の互いの接点を結んだ球面の表面積を表わす。
【００１０】Ｑ：無機粒子が合成樹脂エマルジョン粒子
の表面を最密に被覆したときの無機粒
（ａ＝合成樹脂エマルジョン粒子の平均半径、ｂ＝無機
粒子の平均半径）｝Ｑは、エマルジョン粒子の表面を最
密充填状態で被覆した無機粒子１ケ当りの粒子間のすき
間を含んで占める表面を表わしている。つまり、エマル
ジョン粒子表面を最密充填状態で被覆した無機粒子の互
いに接触している任意の３ケＡ、Ｂ、Ｃをとり、夫々の
粒子の中心を通る面で切断した切断面の隣り合う２ケの
粒子Ａ、Ｂの中心を結ぶ線と、切断面においてこの２ケ
の粒子に接触する他の粒子Ｃとの接点から、前述の２ケ
の粒子の中心を結ぶ線と、Ｃ粒子の中心を通る直線によ
り囲まれる面積のことである。この面積は、Ａ、Ｂ粒子
の中心を結ぶ距離ｂ＋ｂ＝２ｂと、Ｃ粒子と他の粒子
なおＣ粒子と他の粒子の接点とＡまたはＢ粒子の距離
は、Ｃ粒子とＡ粒子の中心距離が２ｂでありＣ粒子の中
心を通る直線との角度が６０°であるから２ｂｓｉｎ６
０゜となる。
【００１１】Ｎは、無機粒子が最密被覆の際、１ヶ当た
りの方形の面積が、その方形が位置する球面（半径ａ＋
ｂ）の表面にいくつあるかである。本発明に於て、均一
に被覆するということは最密に被覆する必要はなく、偏
りなく、平均的に被覆していることが大切である。その
ためには（Ｒ）はＮの５０％以上、好ましくは７０％以
上でなければならない。（Ｒ）がＮの５０％未満では、
露出部分が多くなりそのため大きい凝集体を形成するこ
とになる。すなわち、露出している合成樹脂エマルジョ
ン粒子の負のイオン性により疎らに被覆した正の粒子を
介して他の合成樹脂エマルジョン粒子が密着し、凝集し
て大きい凝集体となる。（Ｒ）の上限はとくに制限はな
いが、余分の無機粒子はいたずらに浮游しているだけで
あるから、実用的には１５０％程度が適当である。
【００１２】本発明の第４の特徴は、このように特定の
エマルジョンと無機微粉末の水性分散液の混合物を噴霧
乾燥することである。前述の通り、液状で電荷を有する
合成樹脂エマルジョンと反対電荷を有する無機微粉末分
散液を混合してエマルジョン粒子を被覆することは本発
明が行ったが、単に電荷で結合した粉末は通常乾燥工程
で電荷が失われ、両者が分離するので、噴霧乾燥時にブ
ロッキングが発生すると考えられていたが、本発明者の
研究により特定の粒径の粒子を特定の数比で結合させか
つ乾燥中の熱により噴霧乾燥しても粒子の分離が発生し
ないことが解明され、本発明が完成された。
【００１３】本発明で用いるエマルジョン粒子として
は、ポリ酢酸ビニル、ポリアクリル酸エステル、ポリエ
チレン、ポリプロピレン、ポリスチレン、酢酸ビニルー
エチレンコポリマー、酢酸ビニル−（メタ）アクリル酸
エステルコポリマー、スチレン−（メタ）アクリル酸エ
ステルコポリマー、酢酸ビニル−ベオバ（シェル化学株
式会社製のビニルエステル）コポリマーなどの熱可塑性
樹脂粒子がある。これ等の合成樹脂粒子は、平均粒径
０．０１〜５０μｍのものが適当である。合成樹脂エマ
ルジョンは再乳化させ室温で使用する点から、ガラス転
移点２０℃以下のものが好ましい。
【００１４】樹脂粒子の分散液は、乳化重合法や懸濁重
合法によって作ることができる。又、ポリマーを後乳化
することによっても作ることができる。このようにして
平均粒子径０．０１〜５０μｍの範囲の樹脂粒子の分散
液が得られる。
【００１５】得られる分散液は、組成や製法によって正
または負に荷電させることが出来る。荷電させる方法と
しては、カチオン性又はアニオン性単量体、および正又
は負のポリマー末端を与える重合開始剤、およびカチオ
ン性又はアニオン性の重合性乳化剤のいずれかを選択的
に単独又は併用して、必要により非イオン性単量体や他
の乳化剤とともにラジカル重合する方法が用いられる。
【００１６】カチオン性単量体としては、例えばジエチ
ルアミノエチルメタクリレート、ジメチルアミノエチル
メタクリレートなどがあげられ、アニオン性単量体とし
ては、例えばアクリル酸、メタクリル酸等があげられ
る。これ等のイオン性単量体はそれぞれ単独で重合して
もよく、又他の非イオン性単量体と組合せて用いてもよ
い。イオン性単量体だけで荷電させるためには、非イオ
ン性単量体１００重量部に対して、イオン性単量体０．
０１重量部以上、ことに０．２重量部以上の使用が好ま
しい。０．０１重量部未満では得られた粒子の帯電量が
不足し、本発明の目的に使用出来ない。
【００１７】正のポリマー末端を与える重合開始剤とし
ては、２，２′−アゾビス（２−アミジノプロパン）塩
酸塩等があげられる。負のポリマー末端を与える重合開
始剤としては、例えば過硫酸ナトリウム、過硫酸カリウ
ム、過硫酸アンモニウム等があげられる。これ等の重合
開始剤は、ラジカル重合性単量体１００重量部に対して
０．０１〜２０重量部、ことに０．２〜１０重量部の使
用が好ましい。また、正又は負のポリマー末端を与えな
い重合開始剤、例えば過酸化ベンゾイル、過酸化ラウロ
イル等を併用してもよい。
【００１８】カチオン性の重合性乳化剤としては、アル
キルジメチルアンモニウムクロライドとアリルエーテル
化合物との合成化合物があり、アニオン性の重合性乳化
剤としては、アルキルアリルスルホサクシネートのアル
カリ塩や、ビニルスルホン酸のアルカリ塩等がある。勿
論他の乳化剤と併用してもよい。しかしながら、重合性
乳化剤を使用するか又は全く乳化剤を使用せずに重合し
た、所謂ソープフリー重合法で得られた乳化重合体は、
とくに均一に被覆された複合体粒子を作るために好適で
ある。
【００１９】本発明で用いる無機質粒子としては、シリ
カ、アルミナ、酸化鉄、酸化チタン、酸化亜鉛などの金
属酸化物、炭酸カルシウム、蓚酸カルシウム、硫酸バリ
ウムなどの塩、水酸化マグネシウム等の水酸化物等が適
当である。しかして、これらの無機質粒子は、平均粒径
０．００５〜２５μｍのものが適当である。無機質粒子
の分散液を作るには、前述の無機質物質を粉砕し、三本
ロール、ペブルミル、超音波分液などの公知の方法で水
又は含水した非水溶剤に分散させるか、又はコロイドゾ
ル合成法により合成すればよい。このようにして、粒子
径０．００５〜２５μｍの範囲の無機質粒子の分散液が
得られる。
【００２０】得られた分散液は無機物質の種類によって
正又は負に荷電しているが、ｐＨを変えることによって
ζ電位が変わり、負又は正に変え調整することが出来
る。このような荷電は、水素イオン、水酸イオン、電位
決定イオン、又は高原子価を有する対イオンによっても
たらされる。
【００２１】エマルジョン粒子と無機粉末の電荷の強さ
は、ζ電位として測定することができる。具体例とし
て、水酸化マグネシウムの分散液はｐＨ０からｐＨ約１
２で正に帯電しており、コロイドゾル合成法により合成
したコロイダルシリカは、ｐＨが約３以下で正電荷、ｐ
Ｈが約３以上で負電荷を示す。
【００２２】本発明のエマルジョン粉末を製造する例を
示すと、例えば水に分散させた、平均粒子径０．０２μ
ｍのコロイド状シリカ粒子のごとき無機質粒子を被覆す
る粒子として選び、酸を加え撹拌混合してｐＨを調整
し、負に帯電させる。次に、同一ｐＨで正に帯電してい
る、例えば乳化重合した平均粒子径０．１μｍのアクリ
ル系エマルジョンを被覆される粒子として選び、この場
合Ｎは１３０なので、この粒子数をエマルジョン粒子に
対して１３０×０．５＝６５以上になるように両方の分
散液を調整して混合し、緩やかに１０分〜２時間撹拌す
れば合成樹脂エマルジョン粒子に無機粒子が極めて均一
に、かつ強固に付着し、合成樹脂エマルジョン粒子を無
機粒子で均一に被覆した分散液が得られる。両分散液を
混合する場合、硫酸カリウム、塩化マグネシウム、塩化
アルミニウムなどの無機電解質を添加すると、より均一
に、かつ緻密に被覆することが出来る。これは無機電解
質が無機粒子のシャドー効果を減少させるため被覆率の
増加をもたらすものと考えられる。こうして得られた混
合液を熱風中に噴霧して樹脂粉末とする。
【００２３】
【実施例】
製造例１
撹拌器、還流冷却器、滴下漏斗、温度計を備えた容量２
Ｌの四ツ口フラスコ中に、水１５１２ｇ、アクリルアミ
ド１４ｇ、ジメチルホルムアミド１６８ｇ、塩化ナトリ
ウム４ｇ、過硫酸カリウム６ｇを入れ、窒素置換後７０
℃まで昇温し１時間重合反応を行った。ついでアクリル
酸ブチル１６５ｇ、メタクリル酸メチル１１５ｇを添加
し７０℃で４時間重合反応を行い次にジエチルアミノエ
チルメタクリレートを１４ｇ加え、さらに１時間重合反
応を行い平均粒子径１．３μｍの合成樹脂エマルジョン
を得た。
【００２４】製造例２
製造例１で用いた四ツ口フラスコ中に水１４００ｇアク
リルアミド１４ｇをジメチルホルムアミド１６８ｇ、塩
化ナトリウム４ｇ、Ｖ−５０（和光純薬工業株式会社
製、２．２′−アゾビス（２−アミジノプロパン）塩酸
塩）の５％水溶液１２０ｇを入れ、窒素置換後７０℃ま
で昇温し１時間重合反応を行った。ついでアクリル酸ブ
チル１４２ｇ、スチレン１３８ｇを添加し７０℃で４時
間重合反応を行い次にジエチルアミノエチルメタクリレ
ートを１４ｇ加え、さらに１時間重合反応を行い平均粒
子径１．６μｍの合成樹脂エマルジョンを得た。
【００２５】製造例３
製造例１で用いた四ツ口フラスコ中に水１４００ｇアク
リルアミド１４ｇジメチルホルムアミド１６８ｇ、塩化
ナトリウム４ｇ、Ｖ−５０（和光純薬工業株式会社製）
の５％水溶液１２０ｇを入れ、窒素置換後７０℃まで昇
温し１時間重合反応を行った。ついで酢酸ビニル１２４
ｇ、ベオバ１０（シェル化学株式会社製のビニルエステ
ル）１７０ｇを添加し７０℃で４時間重合反応を行い平
均粒子径１．１μｍの合成樹脂エマルジョンを得た。
【００２６】製造例４
製造例１で用いた四ツ口フラスコ中に水１３００ｇアク
リルアミド１４ｇをジメチルホルムアミド１６８ｇ、塩
化ナトリウム４ｇ、ラテムルＫ−１８０（花王石鹸株式
会社製のカチオン性重合性乳化剤）１０ｇ、Ｖ−５０
（和光純薬工業株式会社製）の５％水溶液１２０ｇを入
れ、窒素置換後７０℃まで昇温し１時間重合反応を行っ
た。ついでアクリル酸ブチル１４２ｇ、スチレン１３８
ｇを添加し７０℃で４時間重合反応を行い次にジエチル
アミノエチルメタクリレートを１４ｇ加え、さらに１時
間重合反応を行い平均粒子径０．４μｍの合成樹脂エマ
ルジョンを得た。
【００２７】製造例５
製造例１で用いた四ツ口フラスコ中に水１１００ｇ、過
硫酸カリウム１．７ｇを入れ窒素置換後７５℃まで昇温
した。次いでメタクリル酸７ｇアクリル酸ブチル２８５
ｇ。スチレン１９５ｇを添加し７５℃で４時間重合反応
を行い平均粒子径０．７μｍの合成樹脂エマルジョンを
得た。
【００２８】実施例１
製造例１で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に平均粒子径０．０１５μｍのスノーテ
ックスＯ（日産化学工業株式会社製のシリカゾル）の１
０％分散液をｐＨ５に調整した。このスノーテックス分
散液は負に帯電していた。この分散液１０ｇを前記の希
釈エマルジョン１００ｇに添加し、緩やかに撹拌して、
エマルジョン粒子がシリカゾル粒子で均一に被覆された
分散液を得た。このとき粒子数比ＲはＮの約１００％に
当る。走査型電子顕微鏡で観察するとエマルジョン粒子
表面がシリカ粒子で充分均一に覆われていることが確認
された。この複合化された分散液を、噴霧乾燥雰囲気温
度１００℃、堆積樹脂粒子温度６０℃の条件で噴霧乾燥
して合成樹脂エマルジョン粉末を得た。
【００２９】実施例２
製造例２で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に平均粒子径０．０１５μｍのスノーテ
ックスＯ（日産化学工業株式会社製のシリカゾル）の１
０％分散液をｐＨ５に調整した。このスノーテックス分
散液は負に帯電していた。この分散液４．２ｇを前記の
希釈エマルジョン１００ｇに添加し、緩やかに撹拌し
て、エマルジョン粒子がシリカゾル粒子で均一に被覆さ
れた分散液を得た。このとき粒子数比ＲはＮの約５２％
に当る。走査型電子顕微鏡で観察するとエマルジョン粒
子表面がシリカ粒子で充分均一に覆われていることが確
認された。この複合化された分散液を、噴霧乾燥雰囲気
温度１００℃、堆積樹脂粒子温度６０℃の条件で噴霧乾
燥して合成樹脂エマルジョン粉末を得た。
【００３０】実施例３
製造例３で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に平均粒子径０．０１５μｍのスノーテ
ックスＯ（日産化学工業株式会社製のシリカゾル）の１
０％分散液をｐＨ５に調整した。このスノーテックス分
散液は負に帯電していた。この分散液１ｇを前記の希釈
エマルジョン１００ｇに添加し、緩やかに撹拌して、エ
マルジョン粒子がシリカゾル粒子で均一に被覆された分
散液を得た。このとき粒子数比ＲはＮの約８３％に当
る。走査型電子顕微鏡で観察するとエマルジョン粒子表
面がシリカ粒子で充分均一に覆われていることが確認さ
れた。この複合化された分散液を、噴霧乾燥雰囲気温度
１００℃、堆積樹脂粒子温度６０℃の条件で噴霧乾燥し
て合成樹脂エマルジョン粉末を得た。
【００３１】実施例４
製造例４で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に平均粒子径０．０１５μｍのスノーテ
ックスＯ（日産化学工業株式会社製のシリカゾル）の１
０％分散液をｐＨ５に調整した。このスノーテックス分
散液は負に帯電していた。この分散液５ｇを前記の希釈
エマルジョン１００ｇに添加し、緩やかに撹拌して、エ
マルジョン粒子がシリカゾル粒子で均一に被覆された分
散液を得た。このとき粒子数比ＲはＮの約７２％に当
る。走査型電子顕微鏡で観察するとエマルジョン粒子表
面がシリカ粒子で充分均一に覆われていることが確認さ
れた。この複合化された分散液を、噴霧乾燥雰囲気温度
１００℃、堆積樹脂粒子温度６０℃の条件で噴霧乾燥し
て合成樹脂エマルジョン粉末を得た。
【００３２】実施例５
製造例５で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを４に調整した。この希釈エマルジョンは負に帯
電していた。別に酸化チタンＪＲ（帝国化工株式会社製
の平均粒子径０．３μｍのルチル型酸化チタン）をボー
ルミルで水に分散させて５％の水性分散液をｐＨ４に調
整した。このチタン分散液は正に帯電していた。この分
散液２６６ｇを前記の希釈エマルジョン１００ｇに添加
し、緩やかに撹拌して、エマルジョン粒子がチタン粒子
で均一に被覆された分散液を得た。このとき粒子数比Ｒ
はＮの約１００％に当る。走査型電子顕微鏡で観察する
とエマルジョン粒子表面がシリカ粒子で充分均一に覆わ
れていることが確認された。この複合化された分散液
を、噴霧乾燥雰囲気温度１００℃、堆積樹脂粒子温度６
０℃の条件で噴霧乾燥して合成樹脂エマルジョン粉末を
得た。
【００３３】比較例１
製造例１で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に製造例１で用いた四ツ口フラスコ中に
水３６．１ｇ、２８％アンモニア水２８０．４ｇ、エタ
ノール７９３ｇを加えて撹拌した後、５８．３ｇのオル
トケイ酸エチルを加え３０分間撹拌した。ついで４６
６．６ｇのオルト珪酸エチルを添加撹拌後、透析して固
形分１９．２％、平均粒子径１．５９μｍのシリカコロ
イド水性分散液を得た。この分散液をｐＨ５に調整した
ところ負の電荷であった。この分散液２５０ｇを前記の
希釈エマルジョン１００ｇに添加し、緩やかに撹拌した
が均一に被覆された分散液は得られず大きな凝集塊が生
成していた。このとき粒子半径比（ａ／ｂ）は約０．８
で２倍以下であった。
【００３４】比較例２
製造例５で得たエマルジョンを水で１０％に希釈しアン
モニア水でｐＨを１０に調整した。この希釈エマルジョ
ンは負に帯電していた。別に平均粒子径０．０１５μｍ
のスノーテックスＯ（日産化学工業株式会社製のシリカ
ゾル）の１０％分散液をｐＨ１０に調整した。このスノ
ーテックス分散液は負に帯電していた。この分散液１８
ｇを前記の希釈エマルジョン１００ｇに添加し、緩やか
に撹拌した。走査型電子顕微鏡で観察するとエマルジョ
ン粒子とシリカ粒子は複合化されず個々に分散している
ことが確認された。この混合分散液を、噴霧乾燥雰囲気
温度１００℃、堆積樹脂粒子温度６０℃の条件で噴霧乾
燥したところ、得られたものはブロック化していた。
【００３５】比較例３
製造例１で得たエマルジョンを水で１０％に希釈し塩酸
でｐＨを５に調整した。この希釈エマルジョンは正に帯
電していた。別に平均粒子径０．０１５μｍのスノーテ
ックスＯ（日産化学工業株式会社製のシリカゾル）の１
０％分散液をｐＨ５に調整した。このスノーテックス分
散液は負に帯電していた。この分散液３０ｇを前記の希
釈エマルジョン１００ｇに添加し、緩やかに撹拌して、
エマルジョン粒子がシリカゾル粒子で均一に被覆された
分散液を得た。このとき粒子数比ＲはＮの約３０％に当
る。走査型電子顕微鏡で観察するとエマルジョン粒子と
シリカ粒子とが凝集して大きい凝集塊が生成していた。
実施例と比較例の組成を表１に示し、その結果も併せて
示す。
【００３６】
【表１】【００３７】〔註〕 ＊１ 粉末の状態： 均一な粉末
が得られるかを観察した。
＊２ 耐ブロッキング性： ２４時間５０℃で２００ｇ
／ｃｍ２負荷で貯蔵した後、容易に解粒するかを確認し
た。
のエマルジョンとなる。
【００３８】
【発明の効果】本発明のエマルジョン粉末は良好な粉末
状態であり、耐ブロッキング性が著しく優れている。Description: FIELD OF THE INVENTION The present invention relates to powdered emulsions. The powdery emulsion has excellent blocking resistance and good re-emulsification property, and is very useful as an admixture for cement and the like. 2. Description of the Related Art Synthetic resin emulsion powders are easier to prepare in the field, have better handleability and workability, can be accurately prepared, and other powders than synthetic resin aqueous emulsions. It is used as an admixture for cement-based or gypsum-based compositions, a paint, or a component of various adhesives because it is easily mixed with. The synthetic resin emulsion powder must be re-emulsified and used at room temperature so that the glass transition point of the synthetic resin must be 20 ° C. or lower.
Since such a synthetic resin is soft, the emulsion powder has a property of easily sticking to each other. Therefore, there has been a problem that powder particles are coagulated and blocked during the production of the synthetic resin emulsion powder or during storage and storage. Conventionally, as a means for preventing blocking, synthetic resin powder particles formed by adding inorganic fine powder having an average particle diameter of 0.01 to 0.5 μm, such as silica, calcium carbonate, and aluminum silicate, at the time of producing a synthetic resin emulsion powder. There is known a method of coating a powder with an inorganic fine powder. (Japanese Patent Publication No. 55-50971, Japanese Patent Publication No. 46-129)
07) However, the inorganic fine powder as an anti-blocking agent cannot obtain a sufficient effect unless a large amount of 3 to 30% by weight based on the synthetic resin is used. The water / cement ratio is increased due to the water absorption of the powder, and the final strength is inferior to the original synthetic resin aqueous emulsion. In addition, during production, specifically, when coating with inorganic fine particles before and after spray drying, the emulsion particles are not coated in the state of primary particles, so that the glass transition point is -40 ° C., in which the caking is particularly remarkable.
The powdering of the following synthetic resin aqueous emulsion was difficult due to the problem of blocking. (JP-A-4-2557
60) The present inventor has completed the invention of JP-A-62-213839, and in a liquid state, coats emulsion particles with an inorganic powder to obtain a uniform mixture of the inorganic powder and the emulsion. Provided the liquid. According to the present invention, the surface of the emulsion is coated with a minimum amount of inorganic powder to prevent blocking, and the performance of the re-emulsified emulsion is almost the same as that of the original emulsion. An emulsion powder is provided. Means for Solving the Problems The present invention is directed to “1. (A) a synthetic resin aqueous emulsion particle having a positive or negative charge on the particle surface and (B) having an opposite charge to the emulsion particle. A dispersion liquid of inorganic fine particles having an average radius of 1/2 or less of the average radius of the emulsion particles is (However, a is the average radius of the emulsion particles, b is the average radius of the inorganic particles, and R is the number of particles of the inorganic powder / the number of the emulsion particles), and the mixture is spray-dried (C). A synthetic resin emulsion powder having blocking resistance, obtained by coating the surface of the emulsion powder with an inorganic powder. 2. The synthetic resin emulsion with the charge of (A)
Emulsion obtained by emulsion polymerization using one or more selected from a cationic or anionic monomer, a polymerization initiator giving a positive or negative terminal and a cationic or anionic polymerizable emulsifier. The blocking resistant synthetic resin emulsion powder according to item 1. 3. The blocking resistant synthetic resin emulsion powder according to item 1, which is obtained by emulsion polymerization using a cationic monomer or an anionic monomer in an amount of 0.01 part by weight or more based on 100 parts by weight of the nonionic monomer. 4. The blocking-resistant synthetic resin emulsion powder according to item 1, which is emulsion-polymerized by using 0.01 to 20 parts by weight of a polymerization initiator that gives a positive or negative terminal to 100 parts by weight of a polymerizable monomer. 5. 5. The charged inorganic fine particles of (B) are inorganic powders whose charge is adjusted by adding an acid or an alkali to an aqueous dispersion to adjust the pH. Anti-blocking synthetic resin emulsion powder. 6. The blocking resistant synthetic resin emulsion powder according to any one of items 1 to 5, wherein the synthetic resin emulsion is a synthetic resin emulsion having a glass transition point of 20 ° C. or lower. Regarding The present invention relates to a synthetic resin emulsion powder in which the surface of powder particles is uniformly coated with an inorganic fine powder, and the present invention relating to such an emulsion powder has several features. The first feature of the present invention is to mix an aqueous emulsion of synthetic resin having an electric charge on the surface of a particle with an aqueous dispersion of an inorganic fine powder having an opposite charge to form an inorganic fine particle on the surface of the emulsion particle. This is to coat the powder by electrically adsorbing it. Since the particles are electrically adsorbed, other inorganic particles adhere to the surface on which the inorganic particles are not adhered and the surface of the emulsion particles is uniformly covered with the inorganic particles. The second feature of the present invention is that the average radius of the particles of the inorganic fine powder is 1/2 or less of the average radius of the emulsion particles. It is necessary that the radius a of the emulsion particles to be coated be greater than twice the radius b of the inorganic particles to be coated. This is because when the particle diameter ratio a / b of both particles is 2 or less, a complex in which individual emulsion particles are uniformly coated with inorganic particles cannot be obtained, and large aggregates are formed. The third feature of the present invention is that the ratio of the numbers of emulsion particles and inorganic particles to be mixed is set to a special range. The most important requirement for uniform coating is the ratio of the number of inorganic particles and emulsion particles, that is, the number of shell-forming particles divided by the number of core particles (R).
Satisfies the following equation. (R)> N × 0.5 N: Number of inorganic particles required to cover the surface of one synthetic resin emulsion particle most closely. P: Surface area when one particle of synthetic resin emulsion particle is coated with the inorganic particle = radius (a + b).
Spherical surface of = 4π (a + b) 2 This P is a spherical surface area whose radius is the length of the emulsion particles and the radius of the coated inorganic particles, that is, of the inorganic particles coated in the closest packed state on the emulsion particle surface. It represents the surface area of the spherical surface connecting the points of contact with each other. Q: Inorganic particles when the inorganic particles cover the surface of the synthetic resin emulsion particles most closely. (A = average radius of synthetic resin emulsion particles, b = average radius of inorganic particles)} Q is the surface of the emulsion particles covered with the closest packing state, including the interparticle gap, Is represented. In other words, the three adjacent particles A, B, and C that are in contact with each other of the inorganic particles that cover the surface of the emulsion particles in the closest packing state are taken, and the adjacent cut surfaces are cut along the plane that passes through the center of each particle. The line connecting the centers of the two particles A and B, and the line connecting the centers of the two particles described above from the contact point of another particle C contacting the two particles on the cut surface, and the center of the C particle The area surrounded by a straight line passing through. This area is the distance b + b = 2b connecting the centers of A and B particles, and C particle and other particles. The distance between the contact point between the C particle and another particle and the A or B particle is 2bsin6 because the center distance between the C particle and the A particle is 2b and the angle with the straight line passing through the center of the C particle is 60 °.
It becomes 0 °. [0011] N is the area of a square per unit when the inorganic particles are closest packed, and the area of the square is the spherical surface (radius a +
How many are on the surface of b). In the present invention, the uniform coating does not need to be the densest coating, and it is important that the coating is uniform without unevenness. For that purpose, (R) must be 50% or more, preferably 70% or more of N. When (R) is less than 50% of N,
There will be more exposed areas and therefore larger aggregates will form. That is, other synthetic resin emulsion particles adhere to each other via the positive particles sparsely covered by the negative ionicity of the exposed synthetic resin emulsion particles, and agglomerate into large aggregates. The upper limit of (R) is not particularly limited, but since the excess inorganic particles are merely floating unnecessarily, about 150% is suitable for practical use. The fourth feature of the present invention is to spray-dry the mixture of the specific emulsion and the aqueous dispersion of the inorganic fine powder as described above. As described above, the present invention was carried out by coating the emulsion particles by mixing a liquid synthetic resin emulsion having an electric charge and an inorganic fine powder dispersion having an opposite electric charge. It was thought that blocking occurs during spray drying because the charge is lost at the time of separation and the two are separated.However, according to the research of the present inventor, particles of a specific particle size are combined at a specific number ratio and heat during drying is reduced. It was clarified that separation of particles did not occur even by spray drying, and the present invention was completed. The emulsion particles used in the present invention include polyvinyl acetate, polyacrylic acid ester, polyethylene, polypropylene, polystyrene, vinyl acetate-ethylene copolymer, vinyl acetate- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic. There are thermoplastic resin particles such as acid ester copolymers, vinyl acetate-Veova (vinyl ester manufactured by Shell Chemical Co.) copolymers and the like. It is suitable that these synthetic resin particles have an average particle diameter of 0.01 to 50 μm. The synthetic resin emulsion having a glass transition point of 20 ° C. or lower is preferable from the viewpoint of re-emulsification and use at room temperature. The dispersion liquid of resin particles can be prepared by an emulsion polymerization method or a suspension polymerization method. It can also be made by post-emulsifying the polymer. In this way, a dispersion liquid of resin particles having an average particle diameter of 0.01 to 50 μm is obtained. The resulting dispersion can be positively or negatively charged depending on the composition and manufacturing method. As a method for charging, either a cationic or anionic monomer, a polymerization initiator which gives a positive or negative polymer terminal, and a cationic or anionic polymerizable emulsifier are selectively used alone or in combination. A radical polymerization method may be used together with a nonionic monomer and other emulsifiers if necessary. Examples of the cationic monomer include diethylaminoethyl methacrylate and dimethylaminoethyl methacrylate, and examples of the anionic monomer include acrylic acid and methacrylic acid. These ionic monomers may be polymerized individually, or may be used in combination with other nonionic monomers. In order to charge only the ionic monomer, 100 parts by weight of the nonionic monomer should be added to the ionic monomer of 0.
It is preferred to use at least 01 parts by weight, especially at least 0.2 parts by weight. If the amount is less than 0.01 parts by weight, the amount of charge of the obtained particles is insufficient and the particles cannot be used for the purpose of the present invention. Examples of the polymerization initiator which gives a positive polymer terminal include 2,2'-azobis (2-amidinopropane) hydrochloride. Examples of the polymerization initiator which gives a negative polymer terminal include sodium persulfate, potassium persulfate, ammonium persulfate and the like. These polymerization initiators are preferably used in an amount of 0.01 to 20 parts by weight, especially 0.2 to 10 parts by weight, based on 100 parts by weight of the radically polymerizable monomer. Further, a polymerization initiator which does not give a positive or negative polymer terminal such as benzoyl peroxide or lauroyl peroxide may be used in combination. Cationic polymerizable emulsifiers include synthetic compounds of alkyldimethylammonium chloride and an allyl ether compound, and anionic polymerizable emulsifiers include alkali salts of alkylallyl sulfosuccinate and vinyl sulfonic acid. There are alkali salts and the like. Of course, you may use together with another emulsifier. However, the emulsion polymer obtained by the so-called soap-free polymerization method polymerized using a polymerizable emulsifier or using no emulsifier at all,
It is particularly suitable for producing uniformly coated composite particles. The inorganic particles used in the present invention include metal oxides such as silica, alumina, iron oxide, titanium oxide and zinc oxide, salts such as calcium carbonate, calcium oxalate and barium sulfate, and hydroxides such as magnesium hydroxide. Etc. are suitable. Therefore, it is suitable that these inorganic particles have an average particle size of 0.005 to 25 μm. In order to prepare a dispersion liquid of inorganic particles, the above-mentioned inorganic substance is pulverized and dispersed in water or a non-aqueous solvent containing water by a known method such as three rolls, pebble mill, ultrasonic separation, or a colloid sol synthesis method. It may be synthesized by. In this way, a dispersion liquid of inorganic particles having a particle diameter in the range of 0.005 to 25 μm is obtained. The obtained dispersion liquid is positively or negatively charged depending on the type of the inorganic substance, but the ζ potential is changed by changing the pH and can be adjusted to be negative or positive. Such charges are provided by hydrogen ions, hydroxide ions, potential determining ions, or counterions having a high valence. The electric charge strength of the emulsion particles and the inorganic powder can be measured as ζ potential. As a specific example, a dispersion of magnesium hydroxide has a pH of 0 to a pH of about 1
2 is positively charged, and colloidal silica synthesized by the colloid sol synthesis method has a positive charge at pH of about 3 or less, p
When H is about 3 or more, it shows a negative charge. As an example of producing the emulsion powder of the present invention, for example, an average particle size of 0.02 μ dispersed in water is obtained.
The particles are selected as particles that cover inorganic particles such as m colloidal silica particles, and an acid is added and mixed by stirring to adjust the pH and negatively charge the particles. Next, for example, emulsion-polymerized acrylic emulsion having an average particle size of 0.1 μm, which is positively charged at the same pH, is selected as a particle to be coated. In this case, N is 130, and this number of particles is compared with the emulsion particles. Adjust both dispersions so that 130 × 0.5 = 65 or more and mix them gently and stir gently for 10 minutes to 2 hours to attach the inorganic particles to the synthetic resin emulsion particles extremely uniformly and firmly. Then, a dispersion liquid in which the synthetic resin emulsion particles are uniformly coated with the inorganic particles is obtained. When both dispersions are mixed, if an inorganic electrolyte such as potassium sulfate, magnesium chloride or aluminum chloride is added, more uniform and dense coating can be achieved. It is considered that this is because the inorganic electrolyte reduces the shadow effect of the inorganic particles, resulting in an increase in coverage. The mixed liquid thus obtained is sprayed in hot air to obtain a resin powder. EXAMPLES Production Example 1 Volume 2 equipped with stirrer, reflux condenser, dropping funnel, thermometer
In an L four-necked flask, 1512 g of water, 14 g of acrylamide, 168 g of dimethylformamide, 4 g of sodium chloride and 6 g of potassium persulfate were put, and after nitrogen substitution, 70
The temperature was raised to ° C and the polymerization reaction was performed for 1 hour. Then, 165 g of butyl acrylate and 115 g of methyl methacrylate are added, a polymerization reaction is performed at 70 ° C. for 4 hours, 14 g of diethylaminoethyl methacrylate is added, and a polymerization reaction is further performed for 1 hour to obtain a synthetic resin emulsion having an average particle diameter of 1.3 μm. It was Production Example 2 In the four-necked flask used in Production Example 1, 1400 g of water, 14 g of acrylamide, 168 g of dimethylformamide, 4 g of sodium chloride, V-50 (manufactured by Wako Pure Chemical Industries, Ltd., 2.2'-azobis ( 120 g of a 5% aqueous solution of 2-amidinopropane) hydrochloride) was added, and after nitrogen substitution, the temperature was raised to 70 ° C. and a polymerization reaction was carried out for 1 hour. Then, 142 g of butyl acrylate and 138 g of styrene were added, a polymerization reaction was carried out at 70 ° C. for 4 hours, 14 g of diethylaminoethyl methacrylate was added, and a polymerization reaction was carried out for another 1 hour to obtain a synthetic resin emulsion having an average particle diameter of 1.6 μm. Production Example 3 In the four-necked flask used in Production Example 1, water 1400 g acrylamide 14 g dimethylformamide 168 g, sodium chloride 4 g, V-50 (manufactured by Wako Pure Chemical Industries, Ltd.)
120 g of a 5% aqueous solution of was added, and after nitrogen substitution, the temperature was raised to 70 ° C. and a polymerization reaction was carried out for 1 hour. Then vinyl acetate 124
g, and 170 g of Veova 10 (vinyl ester manufactured by Shell Chemical Co., Ltd.) were added, and a polymerization reaction was performed at 70 ° C. for 4 hours to obtain a synthetic resin emulsion having an average particle diameter of 1.1 μm. Production Example 4 In the four-necked flask used in Production Example 1, 1300 g of water, 14 g of acrylamide, 168 g of dimethylformamide, 4 g of sodium chloride, 10 g of Latemur K-180 (cationic polymerizable emulsifier manufactured by Kao Soap Co., Ltd.), V-50
120 g of a 5% aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added, the temperature was raised to 70 ° C. after nitrogen substitution, and a polymerization reaction was carried out for 1 hour. Then butyl acrylate 142g, styrene 138
g was added and a polymerization reaction was carried out at 70 ° C. for 4 hours, then 14 g of diethylaminoethyl methacrylate was added, and a polymerization reaction was carried out for another 1 hour to obtain a synthetic resin emulsion having an average particle diameter of 0.4 μm. Production Example 5 1100 g of water and 1.7 g of potassium persulfate were placed in the four-necked flask used in Production Example 1 and the temperature was raised to 75 ° C. after purging with nitrogen. Then methacrylic acid 7g Butyl acrylate 285
g. 195 g of styrene was added and a polymerization reaction was carried out at 75 ° C. for 4 hours to obtain a synthetic resin emulsion having an average particle diameter of 0.7 μm. Example 1 The emulsion obtained in Production Example 1 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 1 of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) having an average particle diameter of 0.015 μm
The 0% dispersion was adjusted to pH 5. This Snowtex dispersion was negatively charged. 10 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred,
A dispersion was obtained in which the emulsion particles were uniformly coated with silica sol particles. At this time, the particle number ratio R corresponds to about 100% of N. Observation with a scanning electron microscope confirmed that the surfaces of the emulsion particles were sufficiently uniformly covered with silica particles. The composite dispersion was spray-dried under conditions of a spray-drying atmosphere temperature of 100 ° C. and a deposited resin particle temperature of 60 ° C. to obtain a synthetic resin emulsion powder. Example 2 The emulsion obtained in Production Example 2 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 1 of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) having an average particle diameter of 0.015 μm
The 0% dispersion was adjusted to pH 5. This Snowtex dispersion was negatively charged. 4.2 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred to obtain a dispersion in which emulsion particles were uniformly coated with silica sol particles. At this time, the particle number ratio R is about 52% of N
Hit Observation with a scanning electron microscope confirmed that the surfaces of the emulsion particles were sufficiently uniformly covered with silica particles. The composite dispersion was spray-dried under conditions of a spray-drying atmosphere temperature of 100 ° C. and a deposited resin particle temperature of 60 ° C. to obtain a synthetic resin emulsion powder. Example 3 The emulsion obtained in Production Example 3 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 1 of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) having an average particle diameter of 0.015 μm
The 0% dispersion was adjusted to pH 5. This Snowtex dispersion was negatively charged. 1 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred to obtain a dispersion in which emulsion particles were uniformly coated with silica sol particles. At this time, the particle number ratio R corresponds to about 83% of N. Observation with a scanning electron microscope confirmed that the surfaces of the emulsion particles were sufficiently uniformly covered with silica particles. The composite dispersion was spray-dried under conditions of a spray-drying atmosphere temperature of 100 ° C. and a deposited resin particle temperature of 60 ° C. to obtain a synthetic resin emulsion powder. Example 4 The emulsion obtained in Production Example 4 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 1 of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) having an average particle diameter of 0.015 μm
The 0% dispersion was adjusted to pH 5. This Snowtex dispersion was negatively charged. 5 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred to obtain a dispersion in which emulsion particles were uniformly coated with silica sol particles. At this time, the particle number ratio R corresponds to about 72% of N. Observation with a scanning electron microscope confirmed that the surfaces of the emulsion particles were sufficiently uniformly covered with silica particles. The composite dispersion was spray-dried under conditions of a spray-drying atmosphere temperature of 100 ° C. and a deposited resin particle temperature of 60 ° C. to obtain a synthetic resin emulsion powder. Example 5 The emulsion obtained in Production Example 5 was diluted to 10% with water and the pH was adjusted to 4 with hydrochloric acid. This diluted emulsion was negatively charged. Separately, titanium oxide JR (manufactured by Teikoku Kako Co., Ltd., rutile-type titanium oxide having an average particle diameter of 0.3 μm) was dispersed in water with a ball mill to adjust a 5% aqueous dispersion to pH 4. This titanium dispersion was positively charged. 266 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred to obtain a dispersion in which emulsion particles were uniformly coated with titanium particles. At this time, the particle number ratio R
Is about 100% of N. Observation with a scanning electron microscope confirmed that the surfaces of the emulsion particles were sufficiently uniformly covered with silica particles. This composite dispersion was spray dried at an ambient temperature of 100 ° C. and a resin particle temperature of 6
Spray drying was performed at 0 ° C. to obtain a synthetic resin emulsion powder. Comparative Example 1 The emulsion obtained in Preparation Example 1 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 36.1 g of water, 280.4 g of 28% ammonia water and 793 g of ethanol were added to the four-necked flask used in Production Example 1 and stirred, and then 58.3 g of ethyl orthosilicate was added and stirred for 30 minutes. Then 46
After adding and stirring 6.6 g of ethyl orthosilicate, the mixture was dialyzed to obtain an aqueous silica colloidal dispersion having a solid content of 19.2% and an average particle diameter of 1.59 μm. When this dispersion was adjusted to pH 5, it had a negative charge. 250 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred, but a uniformly coated dispersion was not obtained and large aggregates were formed. At this time, the particle radius ratio (a / b) is about 0.8.
Was less than double. Comparative Example 2 The emulsion obtained in Production Example 5 was diluted to 10% with water and the pH was adjusted to 10 with aqueous ammonia. This diluted emulsion was negatively charged. Separately average particle diameter 0.015 μm
A 10% dispersion of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) was adjusted to pH 10. This Snowtex dispersion was negatively charged. This dispersion 18
g was added to 100 g of the diluted emulsion and gently stirred. Observation with a scanning electron microscope confirmed that the emulsion particles and the silica particles were not composited but dispersed individually. When this mixed dispersion was spray-dried under the conditions of a spray drying atmosphere temperature of 100 ° C. and a deposited resin particle temperature of 60 ° C., the obtained product was blocked. Comparative Example 3 The emulsion obtained in Production Example 1 was diluted to 10% with water and the pH was adjusted to 5 with hydrochloric acid. The diluted emulsion was positively charged. Separately, 1 of Snowtex O (silica sol manufactured by Nissan Chemical Industries, Ltd.) having an average particle diameter of 0.015 μm
The 0% dispersion was adjusted to pH 5. This Snowtex dispersion was negatively charged. 30 g of this dispersion was added to 100 g of the diluted emulsion and gently stirred,
A dispersion was obtained in which the emulsion particles were uniformly coated with silica sol particles. At this time, the particle number ratio R corresponds to about 30% of N. Observation with a scanning electron microscope revealed that emulsion particles and silica particles were aggregated to form large aggregates.
The compositions of Examples and Comparative Examples are shown in Table 1, and the results are also shown. [Table 1] [Note] * 1 State of powder: It was observed whether a uniform powder was obtained. * 2 Blocking resistance: 200g at 50 ° C for 24 hours
After storing under a load of / cm 2 , it was confirmed that the granules were easily disintegrated. It becomes an emulsion of. The emulsion powder of the present invention is in a good powder state and has extremely excellent blocking resistance.
Claims (1)
たせた合成樹脂水性エマルジョン粒子と（Ｂ）エマルジ
ョン粒子と反対の電荷を持たせたエマルジョン粒子の平
均半径の１／２以下の平均半径を有する、無機微粒子の
分散液を、次の式 （但し、ａはエマルジョン粒子の平均半径、ｂは無機粒
子の平均半径、Ｒは無機粉末の粒子数／エマルジョン粒
子数である。）を満足する比率で混合し、（Ｃ）該混合
物を噴霧乾燥して得た、エマルジョン粉末表面を無機粉
末で被った、耐ブロッキング性合成樹脂エマルジョン粉
末。 【請求項２】 （Ａ）の電荷を持った合成樹脂エマルジ
ョンが、カチオン性またはアニオン性単量体、正または
負の末端を与える重合開始剤およびカチオン性またはア
ニオン性の重合性乳化剤のいずれかから選んだ１または
２以上を用いて乳化重合して得た、エマルジョンであ
る、請求項１に記截された耐ブロッキング性合成樹脂エ
マルジョン粉末。 【請求項３】 カチオン性単量体またはアニオン性単量
体を非イオン性単量体１００重量部に対し０．０１重量
部以上使用して乳化重合した、請求項１に記載された耐
ブロッキング性合成樹脂エマルジョン粉末。 【請求項４】 正または負の末端を与える重合開始剤
を、重合性単量体１００重量部に対して０．０１〜２０
重量部用いて乳化重合した、請求項１に記載された耐ブ
ロッキング性合成樹脂エマルジョン粉末。 【請求項５】 （Ｂ）の電荷を持った無機粉微粒子が、
水性分散液に酸またはアルカリを加えｐＨを調整するこ
とにより電荷を調整した無機粉末である、請求項１ない
し４のいずれか１項に記載された耐ブロッキング性合成
樹脂エマルジョン粉末。 【請求項６】 合成樹脂エマルジョンがガラス転移点２
０℃以下の合成樹脂エマルジョンである、請求項１ない
し５のいずれか１項に記載された耐ブロッキング性合成
樹脂エマルジョン粉末。What is claimed is: (A) An average of (A) synthetic resin aqueous emulsion particles having a positive or negative charge on the particle surface and (B) emulsion particles having a charge opposite to that of the emulsion particles. A dispersion liquid of inorganic fine particles having an average radius of 1/2 or less of the radius is expressed by the following formula (However, a is the average radius of the emulsion particles, b is the average radius of the inorganic particles, and R is the number of particles of the inorganic powder / the number of the emulsion particles), and the mixture is spray-dried (C). A synthetic resin emulsion powder having blocking resistance, obtained by coating the surface of the emulsion powder with an inorganic powder. 2. The charged synthetic resin emulsion of (A) is a cationic or anionic monomer, a polymerization initiator giving a positive or negative terminal, and a cationic or anionic polymerizable emulsifier. The blocking resistant synthetic resin emulsion powder according to claim 1, which is an emulsion obtained by emulsion polymerization using one or more selected from the above. 3. The anti-blocking method according to claim 1, wherein the cationic monomer or the anionic monomer is used in an amount of 0.01 part by weight or more based on 100 parts by weight of the nonionic monomer to carry out emulsion polymerization. Synthetic resin emulsion powder. 4. A polymerization initiator which gives a positive or negative terminal is added in an amount of 0.01 to 20 relative to 100 parts by weight of the polymerizable monomer.
The blocking resistant synthetic resin emulsion powder according to claim 1, which is emulsion-polymerized using parts by weight. 5. The inorganic powder fine particles having a charge of (B) are
The blocking resistant synthetic resin emulsion powder according to any one of claims 1 to 4, which is an inorganic powder having an electric charge adjusted by adding an acid or an alkali to an aqueous dispersion to adjust the pH. 6. The synthetic resin emulsion has a glass transition point of 2.
The blocking resistant synthetic resin emulsion powder according to any one of claims 1 to 5, which is a synthetic resin emulsion at 0 ° C or lower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23596993A JP3219914B2 (en) | 1993-08-18 | 1993-08-18 | Anti-blocking synthetic resin emulsion powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23596993A JP3219914B2 (en) | 1993-08-18 | 1993-08-18 | Anti-blocking synthetic resin emulsion powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0753728A true JPH0753728A (en) | 1995-02-28 |
| JP3219914B2 JP3219914B2 (en) | 2001-10-15 |
Family
ID=16993897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23596993A Expired - Fee Related JP3219914B2 (en) | 1993-08-18 | 1993-08-18 | Anti-blocking synthetic resin emulsion powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3219914B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996034036A1 (en) * | 1995-04-25 | 1996-10-31 | Mitsubishi Rayon Co., Ltd. | Composite and moldings produced therefrom |
| EP0770640A2 (en) * | 1995-10-28 | 1997-05-02 | BASF Aktiengesellschaft | Process for preparing polymer powders which are redispersible in aqueous media |
| JP2001323070A (en) * | 2000-03-08 | 2001-11-20 | Catalysts & Chem Ind Co Ltd | Spherical composite particle and cosmetic blended with the same |
| JP2008069370A (en) * | 2007-12-07 | 2008-03-27 | Kaneka Corp | Method for preventing (meth)acrylic block copolymer pellet from blocking |
| JP2010138365A (en) * | 2008-11-11 | 2010-06-24 | Sekisui Plastics Co Ltd | Polymer particle aggregate, method for producing the same, light diffusion agent, and light-diffusible resin composition |
| JP2010539275A (en) * | 2007-09-14 | 2010-12-16 | ラフバラ ユニヴァーシティー | Method |
| JP2011026561A (en) * | 2009-06-23 | 2011-02-10 | Dic Corp | Method for producing silica dispersing element, energy-ray curable resin composition, and film |
| US7972660B2 (en) | 2005-07-11 | 2011-07-05 | Akzo Nobel Coatings International B.V. | Electrostatic fluidised powder bed coating process |
| JP2012522110A (en) * | 2009-03-31 | 2012-09-20 | スリーエム イノベイティブ プロパティズ カンパニー | Coating composition and method for producing and using the same |
-
1993
- 1993-08-18 JP JP23596993A patent/JP3219914B2/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996034036A1 (en) * | 1995-04-25 | 1996-10-31 | Mitsubishi Rayon Co., Ltd. | Composite and moldings produced therefrom |
| EP0770640A2 (en) * | 1995-10-28 | 1997-05-02 | BASF Aktiengesellschaft | Process for preparing polymer powders which are redispersible in aqueous media |
| EP0770640A3 (en) * | 1995-10-28 | 1997-10-29 | Basf Ag | Process for preparing polymer powders which are redispersible in aqueous media |
| SG81903A1 (en) * | 1995-10-28 | 2001-07-24 | Basf Ag | Preparation of polymer powders which are redispersible in an aqueous medium |
| JP2001323070A (en) * | 2000-03-08 | 2001-11-20 | Catalysts & Chem Ind Co Ltd | Spherical composite particle and cosmetic blended with the same |
| US7972660B2 (en) | 2005-07-11 | 2011-07-05 | Akzo Nobel Coatings International B.V. | Electrostatic fluidised powder bed coating process |
| JP2010539275A (en) * | 2007-09-14 | 2010-12-16 | ラフバラ ユニヴァーシティー | Method |
| JP2008069370A (en) * | 2007-12-07 | 2008-03-27 | Kaneka Corp | Method for preventing (meth)acrylic block copolymer pellet from blocking |
| JP2010138365A (en) * | 2008-11-11 | 2010-06-24 | Sekisui Plastics Co Ltd | Polymer particle aggregate, method for producing the same, light diffusion agent, and light-diffusible resin composition |
| JP2012522110A (en) * | 2009-03-31 | 2012-09-20 | スリーエム イノベイティブ プロパティズ カンパニー | Coating composition and method for producing and using the same |
| US8633263B2 (en) | 2009-03-31 | 2014-01-21 | 3M Innovative Properties Company | Coating composition and method of making and using the same |
| JP2011026561A (en) * | 2009-06-23 | 2011-02-10 | Dic Corp | Method for producing silica dispersing element, energy-ray curable resin composition, and film |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3219914B2 (en) | 2001-10-15 |
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