JP3718568B2 - Polymer emulsion and method for producing the same - Google Patents

Description

（ただし、式中のＲ₁はＨまたはＣＨ₃を、Ｒ₂は炭素数２〜５のアルキレン基を、Ｒ₃及びＲ₄は独立にＨまたは炭素数１〜５のアルキル基を、Ａは
【０００９】
【化６】

を示し、Ｒ₁、Ｒ₃、Ｒ₄は単量体が水に対し難溶性または不溶液性である範囲で選ばれる。）
【００１０】
【発明の実施の形態】
以下、さらに本発明を詳しく説明する。
本発明に種ラテックスとして用いられる合成ゴム系ラテックスまたは合成樹脂系エマルションとしては公知のものをいずれも使用することができる。これらの具体例としては、合成ゴムラテックスでは、スチレン・ブタジエンゴム（ＳＢＲ）、メチルメタアクリレート・ブタジエンゴム（ＭＢＲ）、アクリロニトリル・ブタジエン（ＮＢＲ）、またはこれらに他の単量体成分を含有させたゴム、クロロブレンゴム（ＣＲ）、イソブレンゴム（ＩＲ）などをカルボキシル変性したラテックスが挙げられ、合成樹脂エマルションではアクリル酸エステル系、酢酸ビニル系、塩化ビニル系、スチレン系の重合体又は共重合体、エチレン・酢酸ビニル共重合体、エチレン・塩化ビニル共重合体などをカルボキシル変性したエマルションが挙げられる。カルボキシル変性は、例えば（メタ）アクリル酸、ケイヒ酸、クロトン酸、マレイン酸等のカルボキシル基を有する重合性単量体を共重合したりあるいは高分子反応により重合体に導入する等公知の方法で行うことができる。
【００１１】
本発明に用いられる一般式（１）で表わされる単量体の具体例としては、例えばジエチルアミノエチルアクリレート、ジエチルアミノエチルメタクリレート、ジプロピルアミノエチルアクリレート、ジプロピルアミノエチルメタアクリレート、ジブチルアミノエチルメタアクリレート、ｔ−ブチルアミノエチル（メタ）アクリレート、ジエチルアミノプロピルメタクリルアミド、ジプロピルアミノプロピルメタクリルアミド、ジプロピルアミノプロピルアクリルアミド、ジブチルアミノプロピルメタクリルアミド、ジブチルアミノプロピルアクリルアミドなどが挙げられる。
【００１２】
本発明においては、上記一般式（１）で表わされる単量体とともに、これらと共重合可能な他のエチレン性不飽和単量体を併用してもよい。このようなエチレン性不飽和単量体としては、例えば（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブチルのようなメタクリル酸エステル、アクリロニトリル、スチレン、酢酸ビニル等の疎水性単量体、又はＮ，Ｎ’−メチレンビスアクリルアミド、ジアリルフタレート、ジビニルベンゼン、（ポリ）エチレングリコールジ（メタ）アクリレート等の架橋性単量体が好ましく例示できる。
【００１３】
上記原料の使用量は次のとおりである。
種ラテックスに対する一般式（１）で示される単量体の割合は種ラテックスの固形分に対して５〜５０重量％、好ましくは１０〜３０重量％程度である。一般的なカルボキシル変性ラテックスのコロイド当量値は−０．２〜−０．１ｍｅｑ／ｇであるため、一般式（１）で示される単量体の割合が５重量％未満の場合、カチオン性基が少な過ぎて安定なカチオン性ラテックスは得られない。５０重量％超では、カチオン性基が過剰となり、また経済的にも不利となる。
【００１４】
なおコロイド当量値とは、次の方法で得られる値である。
ビーカーに蒸留水９５ｍｌをとり、試料の１０００ｐｐｍ溶液（固形分ベース）を５ｍｌ加え、１％ＨＣｌでｐＨ＝４．０とし、約１分間撹拌する。次に、トルイジンブルー指示薬溶液を２〜３滴加え、１／４００Ｎポリビニルスルフォン酸カリウム（ＰＶＳＫ）で測定する。測定速度は２ｍｌ毎分とし、検水が青から赤に変色、１０秒間以上保持する時点を終点とする。
【００１５】
【数１】
コロイド当量値（ｍｅｑ／ｇ）
＝（サンプル滴定量−ブランク滴定量）×Ｆ／２
（ただしＦはファクターである。）
【００１６】
他のエチレン性不飽和単量体単量体は目的とするラテックスのガラス転移点や物性に応じて定めればよいが、通常一般式（１）で表される単量体に対して４０重量％以下、好ましくは０．００１〜２５重量％使用する。
【００１７】
重合方法は種ラテックスを水で希釈するかまたは希釈せずに系のｐＨを６以上とし、次いで前記単量体を添加し、好ましくはラジカル重合開始剤存在下、温度２０〜８０℃で撹拌しながらシード重合する。系のｐＨが６未満の場合、単量体添加時あるいは重合時にゲル化して安定なエマルションが得られない。また重合温度は、特に限定されないが、実用上常圧下にて２０〜８０℃、好ましくは３０〜６０℃である。この場合界面活性剤は特に添加する必要はないが、その含有量が不十分なときは、常法に従って添加することもできる。
【００１８】
また本発明で好ましく使用されるラジカル重合開始剤としては、通常の乳化重合に用いられるものが使用される。例えば過硫酸アンモニウム、過硫酸カリウム、過酸化水素等の無機過酸化物、アゾビスイソブチロニトリル、２，２’−アゾビス（２，４−ジメチルバレロニトリル）、２，２’−アゾビス（２−アミジノプロパン）塩酸塩、アゾビス（Ｎ，Ｎ’−ジメチレンイソブチルアミジン）塩酸塩等の脂肪族アゾ化合物類、ベンゾイルパーオキサイド、ｔ−ブチルハイドロパーオキサイド、ジイソプロピルベンゼンハイドロパーオキサイド、クメンハイドロパーオキサイド等のハイドロパーオキサイド類、前記のパーオキサイド類とアスコルビン酸、多価金属塩、酸性亜硫酸ナトリウム、ソジウムホルムアルデヒドスルホキシレート等の還元剤を組合わせたレドックス系等が挙げられる。これらの重合開始剤の使用量としては、単量体に対して１．０〜５．０重量％程度である。
重合方法の態様は回分式、連続式等のいずれの方式であってもよい。
この様にしてシード重合体エマルションを得る。
【００１９】
次いでノニオン型界面活性剤を添加する。本発明で使用されるノニオン型界面活性剤としては、例えばポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンソルビタン脂肪酸エステル、テトラオレイル酸ポリオキシエチレンソルビット等が使用でき、好ましくはＨＬＢで１０から１９程度、さらに好ましくは１２〜１８程度のものである。具体的には、ポリオキシエチレンオクチルフェニルエーテル ＨＬＢ １７．９（商品名 花王エマルゲン８４０Ｓ）、ポリオキシエチレノニルフェニルエーテル ＨＬＢ １２．４（商品名 花王エマルゲン９０９）、同 ＨＬＢ １７．５（商品名 花王エマルゲン９３５）、ポリオキシエチレンラウリルエーテル ＨＬＢ １２．１（商品名 花王エマルゲン１４７）等が挙げられる。これらノニオン型界面活性剤の量はシード重合体エマルションの固形分に対して通常０．１〜４重量％である。添加量が０．１％より少なすぎると凝固物防止効果が少なく、４％を越えると効果はあるが発泡等のトラブルを生じ易い。添加方法はエマルション重合体に所定量を撹拌しながら添加して均一になるまで撹拌する。
【００２０】
次いで得られたポリマーをカチオン化することにより、カチオン性基がラテックス粒子表面に高密度に分布したカチオン性重合体エマルションが得られる。カチオン化の方法としては、得られたシード重合体を室温で撹拌しながら酸又は塩で中和するか、又は一般の４級化剤で４級アンモニウム塩化する方法が挙げられる。酸としては、例えば塩酸、硫酸などの無機酸、アジピン酸、クエン酸、ギ酸などの有機酸等、塩としては硫酸水素ナトリウム、リン酸二水素ナトリウム等の酸性塩等、４級化剤としては塩化メチル、塩化エチル、臭化メチル、ヨウ化メチル等のハロゲン化アルキル、ベンジルクロリド、硫酸ジメチル、硫酸ジエチル等の一般的なアルキル化剤が使用できる。通常使用される一般的な４級化剤の中ではパラトルエンスルホン酸メチルが最も好ましい。一般的な４級化剤として使われる塩化メチル、ベンジルクロリド、硫酸ジエチルは反応性があまり良くなく、得られる重合体ラテックスのカチオン性（コロイド当量値）も低い。それに比べパラトルエンスルホン酸メチルは反応時間も短く、凝固物も少ない。又抄紙やモルタル混和に於けるバインダー効果も非常に良好である。
酸、塩又は４級化剤は、通常は使用した一般式（１）の単量体に対して当量添加する。中和は添加とほぼ同時に完了し、また４級化は通常５分〜３０分間程度で完了する。
【００２１】
この様にして、本発明の表面に高密度にカチオン性が付与された重合体エマルションが得られる。なお、得られた重合体ラテックスに発泡が見られるときは少量の消泡剤等を添加してもとよい。
【００２２】
本発明の重合体エマルションは、粒子表面が高密度にカチオン化されており、帯電防止性、親水性、極性親和性を有するので、凝結剤、製紙用紙力増強バインダー、定着剤、歩留向上剤、その他各種繊維のバインダー、繊維の風合加工、帯電防止加工、防水加工、塗料、接着剤原料、モルタル混和、セメント混和、コンクリート混和、アスファルト混和等の用途に用いられる。
また、特にカチオンをノニオン型界面活性剤存在下で行うことにより、凝固物の生成を非常に低レベルに抑制出来ることができる。
【００２３】
【実施例】
以下実施例を挙げて説明する。なお、％は重量％を意味する。
実験例１ 撹拌機付きフラスコにカルボキシル変性ＳＢＲラテックス７０１．３ｇ（ｐＨ８．３、固形分４８％、アニオンコロイド当量値：−０．１８ｍｅｑ／ｇ）、Ｎ，Ｎ’−メチレンビスアクリルアミド０．４ｇ、および水１５９．７ｇを入れ良く撹拌しながら、ジエチルアミノエチルメタアクリレート３７．５ｇ（硫酸ジメチル４級化物としてカチオンコロイド当量値：０．５１ｍｅｑ／ｇ）を滴下ロートを使用して滴下した後、Ｎ²ガスを吹き込みながら、１時間放置した。放置後、１％過硫酸カリウム水溶液８０ｇを添加し、５０℃に加温して重合させた。約２時間後に重合は完結した。
【００２４】
この重合体エマルションに市販のノニオン型界面活性剤エマルゲン８４０Ｓ（花王（株））製；ポリオキシエチレンオクチルフェニルエーテルを重合体エマルション固形分に対し、０．５％添加した後、重合体エマルションを撹拌しながら、室温にて上記ジエチルアミノエチルメタアクリレートに対して当量の硫酸ジメチル（ＤＭＳ）を添加して３０分間放置し、４級化を行った。
【００２５】
比較例１ 実験例１においてノニオン型界面活性剤を添加しない以外は、同様の操作によって重合体エマルションを得た。
【００２６】
実施例１ 実験例１と同様な操作で重合体エマルションを得、この重合体エマルションにノニオン型界面活性剤エマルゲン８４０Ｓを０．５％添加した後、重合体エマルションを撹拌しながら５０℃にてジエチルアミノエチルメタクリレート対して当量のパラトルエンスルホン酸メチル（ＰＴＳＭ）を添加して２０分間放置して４級化を行い、安定した重合体エマルションを得た。
【００２７】
比較例２ 実施例１においてノニオン型界面活性剤を添加しない以外は同様の操作によって重合体エマルションを得た。
【００２８】
実施例２ 実施例１においてノニオン型界面活性剤エマルゲン９０９を１．０％添加する以外は同様の操作で重合体エマルションを得た。
【００２９】
実験例２ 実験例１において硫酸ジメチルを塩酸に変更する以外は同様の操作で重合体エマルションを得た。
【００３０】
実験例３ 実験例２においてノニオン型界面活性剤をエマルゲン１４７を１．０％添加する以外は同様の操作で重合体エマルションを得た。
【００３１】
比較例３ 実験例２においてノニオン型界面活性剤を除く以外は同様の操作で重合体エマルションを得た。以上の実施例１〜２、実験例１〜３、および比較例１〜３のエマルションについてコロイド当量値と凝固物の量を測定した結果を表１に示した。凝固物の測定は次のようにして行った。得られた最終重合体ラテックスを３００メッシュの金網で濾過した後、１２５℃にて乾燥し、金網に残存した凝固物の重合体固形分に対する割合を測定した。ノニオン型界面活性剤無添加の比較例に比べて、ノニオン型界面活性剤を添加した実施例及び実験例においては凝固物が少なく、さらに４級化剤としてＰＴＳＭを使用した場合は１／１０以下で顕著な相乗効果を生じる。
【００３２】
【表１】

【００３３】
実施例３ ＪＩＳ Ｐ８１２１により測定した叩解度が３８０ｍｌ（Ｃ．Ｓ．Ｆ）のＬＢＫＰの１％パルプスラリーをｐＨ７．５に調整した。実施例１〜２、実験例１〜３、及び比較例１〜３で得られたラテックスを所定量添加混合し、角型シートマシンで坪量６０ｇ／ｍ²のシートを得、３．８ｋｇ／ｍ²で５分間プレスした後、ドラムドライヤーで１２０℃で２分乾燥した。得られたシートの比破裂強さとステキヒトサイズをそれぞれＪＩＳ Ｐ８１１２およびＪＩＳ Ｐ８１２２に基づき測定して表２の結果を得た。なお、中和塩タイプは中性域では定着せず効果は発揮できない。
【００３４】
【表２】

【００３５】
実施例４ ４２０ｍｌ（Ｃ．Ｓ．Ｆ）に叩解したＬＢＫＰの１％パルプスラリーに硫酸バンドを２．５％添加し、最終的にｐＨを４．５に調整したラテックスを所定量添加し、実施例３と同条件でシートを作成し、比破裂強さを測定して表３の結果を得た。
【００３６】
【表３】

【００３７】
実施例５ 実験例１、実施例１、および比較例１、２で得られた重合体エマルションに消泡剤としてノプコ８０３４（サンノプコ社）を固形分に対して０．７％添加混合した。ＪＩＳ Ａ６２０３「セメント混和用ポリマーディスパージョン」の「７．６接着強さ」に準じて、セメント１００重量部、豊浦標準砂３００重量部および水５０重量部に、得られた重合体エマルションを２５重量部混練し、モルタル板に塗り付け試験体とした。湿度６５±１０％、温度２０±２℃で１４日間養生した後、接着強さを測定して表４の結果を得た。
【００３８】
【表４】

【００３９】
【発明の効果】
本発明は種ラテックスとして既製のポリマーラテックスを用いるので、種ラテックスを調整する手間が省け、又シード重合が安定して行え、得られたエマルションの粒子径も均一で、保存性も良好である。また、特にノニオン型界面活性剤存在下でカチオン化を行うことにより、凝固物の生成を非常に低レベルに抑制出来、さらに表面のカチオン化密度が大である。本発明の重合体エマルションは各種混和剤や紙加工剤などの有用な用途がある。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stable polymer emulsion in which cationic groups are distributed at high density on the surface of latex particles and there is little coagulum, and a method for producing the same. More specifically, by imparting cationicity, pulp, synthetic fibers, paper strength enhancing binders or fixing agents in beater size processing when making inorganic fibers, yield improvers, etc., flocking, non-woven fabric, carpet backing, etc. Stable polymer emulsion with low coagulation, suitable for use as a binder, fiber texture, antistatic waterproofing agent, mortar admixture, cement admixture, asphalt admixture, other adhesives, and coating materials And a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, carboxyl-modified latex has been used for binders such as various fibers, asphalt, mortar, concrete or ceramic. Various cationic polymer emulsions have also been proposed, but few have sufficient effects for their intended purpose, and their production methods are complicated. For example, there is a method in which a cationic monomer is copolymerized with another monomer by seed polymerization without using an emulsifier or using a cationic surfactant. This is a method in which a total amount of cationic monomer and a part of another monomer are used to form a seed latex, and the remaining monomer is added to this, so there are many cationic groups on the particle surface. And stable polymerization cannot be performed (Japanese Patent Laid-Open Nos. 57-121048 and 58-142217).
[0003]
Further, an ethylenically unsaturated monomer containing a cationic group-providing group made of a secondary, tertiary amine, or quaternary ammonium salt, and an ethylenically unsaturated monomer copolymerizable therewith There is a method in which a part is polymerized in the presence of a chain transfer agent in an aqueous medium to form a seed latex, and then the remaining both monomers are added to continue the polymerization (Japanese Patent Laid-Open No. 61-261302). Unlike the former method, this method uses a monomer that contains a cationic group in the monomer added to the seed latex, so that an effect of imparting a cationic group to the particle surface 1 can be expected to some extent. The production process is complicated, such as producing seed latex in the presence of a chain transfer agent.
[0004]
For the purpose of improving these technologies, a seed polymer obtained by adding and polymerizing a poorly water-soluble or insoluble cationic monomer to a carboxyl-modified synthetic rubber latex or synthetic resin emulsion as a seed latex and acidifying a seed polymer is obtained. Alternatively, there has been proposed a polymer emulsion in which cationic properties are imparted to the emulsion particle surface at high density by neutralization with a salt or quaternary ammonium chloride with a quaternizing agent (Japanese Patent Laid-Open No. 1-146907). This technique exhibits superior properties such as a higher surface cation density than the above. Paper, mortar, and cement admixtures that apply this are good in terms of improved performance, but in recent years there has been a demand for improved productivity and so on, so that higher performance, low-solidified products are required. It has become to.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a polymer emulsion having a very small amount of coagulum in which cationic property is imparted to the particle surface at a high density. Another object of the present invention is to provide a polymer emulsion exhibiting extremely excellent performance when applied to paper, mortar admixture, cement admixture and the like. Still another object of the present invention is to provide a method for stably producing such a polymer emulsion.
[0006]
[Means for Solving the Problems]
The inventors have used a known synthetic rubber latex or synthetic resin emulsion as a seed latex, seeded with a specific monomer, and added a nonionic surfactant, and then added an acid. Alternatively, neutralization with a salt or quaternary ammonium salification with a quaternizing agent gives an emulsion in which cationic groups are present at a high density on the surface of the polymer particles, and this emulsion is stable with little coagulum. In addition, the production method is simple and does not require complicated operations, and is found to be economically useful. Further, quaternized with methyl paratoluenesulfonate has better performance in application. The present invention has been found.
[0007]
That is, the present invention provides a nonionic surface active agent to a seed polymer obtained by using a synthetic rubber latex or a synthetic resin emulsion as a seed latex and adding and polymerizing a monomer represented by the following general formula (1). After adding the agent, neutralization with an acid or salt, or quaternary ammonium chloride with a quaternizing agent to impart high density cationicity to the emulsion particle surface, resulting in less coagulum Polymer emulsions and methods for their production.
[0008]
[Chemical formula 5]

(Where R ₁ is H or CH ₃ , R ₂ is an alkylene group having 2 to 5 carbon atoms, R ₃ and R ₄ are independently H or an alkyl group having 1 to 5 carbon atoms, A is [0009]
[Chemical 6]

R ₁ , R ₃ and R ₄ are selected in the range where the monomer is hardly soluble or insoluble in water. )
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be further described in detail below.
Any known synthetic rubber-based latex or synthetic resin-based emulsion used as a seed latex in the present invention can be used. Specific examples thereof include synthetic rubber latex containing styrene / butadiene rubber (SBR), methyl methacrylate / butadiene rubber (MBR), acrylonitrile / butadiene (NBR), or other monomer components. Examples include latex obtained by carboxyl-modifying rubber, chlorobrene rubber (CR), isobrene rubber (IR), etc. In synthetic resin emulsions, acrylic ester-based, vinyl acetate-based, vinyl chloride-based, styrene-based polymers or copolymers, An emulsion obtained by carboxyl-modifying ethylene / vinyl acetate copolymer, ethylene / vinyl chloride copolymer and the like can be mentioned. Carboxyl modification is performed by a known method such as copolymerization of a polymerizable monomer having a carboxyl group such as (meth) acrylic acid, cinnamic acid, crotonic acid, maleic acid, or introduction into a polymer by a polymer reaction. It can be carried out.
[0011]
Specific examples of the monomer represented by the general formula (1) used in the present invention include, for example, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dipropylaminoethyl acrylate, dipropylaminoethyl methacrylate, dibutylaminoethyl methacrylate, Examples thereof include t-butylaminoethyl (meth) acrylate, diethylaminopropyl methacrylamide, dipropylaminopropyl methacrylamide, dipropylaminopropyl acrylamide, dibutylaminopropyl methacrylamide, dibutylaminopropyl acrylamide and the like.
[0012]
In the present invention, together with the monomer represented by the general formula (1), another ethylenically unsaturated monomer copolymerizable with these may be used in combination. Such ethylenically unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, methacrylate esters such as butyl (meth) acrylate, acrylonitrile, Preferred examples include hydrophobic monomers such as styrene and vinyl acetate, or crosslinkable monomers such as N, N′-methylenebisacrylamide, diallyl phthalate, divinylbenzene, and (poly) ethylene glycol di (meth) acrylate.
[0013]
The amount of the raw material used is as follows.
The ratio of the monomer represented by the general formula (1) to the seed latex is about 5 to 50% by weight, preferably about 10 to 30% by weight, based on the solid content of the seed latex. Since the colloid equivalent value of a general carboxyl-modified latex is -0.2 to -0.1 meq / g, when the proportion of the monomer represented by the general formula (1) is less than 5% by weight, a cationic group Is too small to obtain a stable cationic latex. If it exceeds 50% by weight, the cationic groups will be excessive, and this will be economically disadvantageous.
[0014]
The colloid equivalent value is a value obtained by the following method.
Take 95 ml of distilled water in a beaker, add 5 ml of a 1000 ppm solution (based on solid content) of the sample, adjust the pH to 4.0 with 1% HCl, and stir for about 1 minute. Next, add 2-3 drops of toluidine blue indicator solution and measure with 1 / 400N potassium polyvinyl sulfonate (PVSK). The measurement speed is 2 ml per minute, and the time point at which the test water changes from blue to red and is maintained for 10 seconds or more is the end point.
[0015]
[Expression 1]
Colloid equivalent value (meq / g)
= (Sample titration-blank titration) x F / 2
(However, F is a factor.)
[0016]
The other ethylenically unsaturated monomer may be determined according to the glass transition point and physical properties of the target latex, but is usually 40% by weight based on the monomer represented by the general formula (1). % Or less, preferably 0.001 to 25% by weight.
[0017]
In the polymerization method, the seed latex is diluted with water or the system is brought to a pH of 6 or more without being diluted, and then the monomer is added, and the mixture is preferably stirred at a temperature of 20 to 80 ° C. in the presence of a radical polymerization initiator. While seed polymerization. When the pH of the system is less than 6, gelation occurs at the time of monomer addition or polymerization, and a stable emulsion cannot be obtained. The polymerization temperature is not particularly limited, but is practically 20 to 80 ° C., preferably 30 to 60 ° C. under normal pressure. In this case, it is not necessary to add the surfactant, but when the content is insufficient, it can be added according to a conventional method.
[0018]
Further, as the radical polymerization initiator preferably used in the present invention, those used in usual emulsion polymerization are used. For example, inorganic peroxides such as ammonium persulfate, potassium persulfate, hydrogen peroxide, azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2- Amidinopropane) hydrochloride, aliphatic azo compounds such as azobis (N, N′-dimethyleneisobutylamidine) hydrochloride, benzoyl peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, etc. Hydroperoxides, redox systems in which the above peroxides are combined with a reducing agent such as ascorbic acid, polyvalent metal salt, acidic sodium sulfite, sodium formaldehyde sulfoxylate, and the like. The amount of these polymerization initiators used is about 1.0 to 5.0% by weight with respect to the monomer.
The mode of the polymerization method may be any system such as a batch system or a continuous system.
In this way, a seed polymer emulsion is obtained.
[0019]
Next, a nonionic surfactant is added. As the nonionic surfactant used in the present invention, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, tetraoleic acid polyoxyethylene sorbite and the like can be used, preferably HLB. About 10 to 19, more preferably about 12-18. Specifically, polyoxyethylene octyl phenyl ether HLB 17.9 (trade name Kao Emulgen 840S), polyoxyethylenonyl phenyl ether HLB 12.4 (trade name Kao Emulgen 909), HLB 17.5 (trade name Kao) Emulgen 935), polyoxyethylene lauryl ether HLB 12.1 (trade name Kao Emulgen 147) and the like. The amount of these nonionic surfactants is usually 0.1 to 4% by weight based on the solid content of the seed polymer emulsion. If the amount added is less than 0.1%, the effect of preventing coagulation is low. If it exceeds 4%, there is an effect, but problems such as foaming are likely to occur. In the addition method, a predetermined amount is added to the emulsion polymer while stirring and stirred until uniform.
[0020]
Then, the resulting polymer is cationized to obtain a cationic polymer emulsion in which cationic groups are distributed at high density on the latex particle surface. Examples of the cationization method include a method in which the obtained seed polymer is neutralized with an acid or a salt while stirring at room temperature, or a quaternary ammonium salt with a general quaternizing agent. Examples of acids include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as adipic acid, citric acid, and formic acid, and salts such as acidic salts such as sodium hydrogen sulfate and sodium dihydrogen phosphate. Common alkylating agents such as alkyl halides such as methyl chloride, ethyl chloride, methyl bromide and methyl iodide, benzyl chloride, dimethyl sulfate and diethyl sulfate can be used. Of the commonly used quaternizing agents, methyl paratoluenesulfonate is most preferred. Methyl chloride, benzyl chloride, and diethyl sulfate used as general quaternizing agents are not very reactive, and the resulting polymer latex has a low cationic property (colloid equivalent value). In contrast, methyl paratoluenesulfonate has a short reaction time and less coagulum. The binder effect in papermaking and mortar blending is also very good.
The acid, salt or quaternizing agent is usually added in an equivalent amount to the monomer of the general formula (1) used. Neutralization is completed almost simultaneously with the addition, and quaternization is usually completed in about 5 to 30 minutes.
[0021]
In this way, a polymer emulsion in which cationicity is imparted to the surface of the present invention at a high density can be obtained. When foaming is observed in the obtained polymer latex, a small amount of antifoaming agent or the like may be added.
[0022]
The polymer emulsion of the present invention has a particle surface that is cationized with high density and has antistatic properties, hydrophilicity, and polar affinity, so that it is a coagulant, paper-making paper strength enhancing binder, fixing agent, and yield improver. , Other fiber binders, fiber texture processing, antistatic processing, waterproofing, paints, adhesive raw materials, mortar blending, cement blending, concrete blending, asphalt blending, etc.
In particular, when the cation is used in the presence of a nonionic surfactant, the formation of a coagulum can be suppressed to a very low level.
[0023]
【Example】
Hereinafter, examples will be described. In addition,% means weight%.
Experimental Example 1 In a flask equipped with a stirrer, 701.3 g of carboxyl-modified SBR latex (pH 8.3, solid content 48%, anion colloid equivalent value: -0.18 meq / g), 0.4 g of N, N'-methylenebisacrylamide, Then, 157.5 g of water and 159.7 g of water were added and 37.5 g of diethylaminoethyl methacrylate (cationic colloid equivalent value as dimethyl sulfate quaternized product: 0.51 meq / g) was dropped using a dropping funnel, and then N ² It was left for 1 hour while blowing gas. After standing, 80 g of 1% potassium persulfate aqueous solution was added, and the mixture was heated to 50 ° C. for polymerization. The polymerization was complete after about 2 hours.
[0024]
Commercially available nonionic surfactant Emulgen 840S (Kao Co., Ltd.); 0.5% of polyoxyethylene octylphenyl ether is added to the polymer emulsion solid content to this polymer emulsion, and then the polymer emulsion is stirred. Then, an equivalent amount of dimethyl sulfate (DMS) was added to the diethylaminoethyl methacrylate at room temperature, and the mixture was allowed to stand for 30 minutes for quaternization.
[0025]
Comparative Example 1 A polymer emulsion was obtained in the same manner as in Experimental Example 1 except that the nonionic surfactant was not added.
[0026]
Example 1 A polymer emulsion was obtained in the same manner as in Experimental Example 1. After adding 0.5% of nonionic surfactant Emulgen 840S to this polymer emulsion, diethylamino was stirred at 50 ° C. while stirring the polymer emulsion. An equivalent amount of methyl paratoluenesulfonate (PTSM) was added to ethyl methacrylate and allowed to stand for 20 minutes for quaternization to obtain a stable polymer emulsion.
[0027]
Comparative Example 2 A polymer emulsion was obtained in the same manner as in Example 1 except that the nonionic surfactant was not added.
[0028]
Example 2 A polymer emulsion was obtained in the same manner as in Example 1 except that 1.0% of the nonionic surfactant Emulgen 909 was added.
[0029]
Experimental Example 2 A polymer emulsion was obtained in the same manner as in Experimental Example 1, except that dimethyl sulfate was changed to hydrochloric acid.
[0030]
Experimental Example 3 A polymer emulsion was obtained in the same manner as in Experimental Example 2 , except that 1.0% of Emulgen 147 was added as a nonionic surfactant.
[0031]
Comparative Example 3 A polymer emulsion was obtained in the same manner as in Experimental Example 2 , except that the nonionic surfactant was removed. Table 1 shows the results of measuring the colloidal equivalent value and the amount of coagulum of the emulsions of Examples 1-2, Experimental Examples 1-3 , and Comparative Examples 1-3. The measurement of the coagulum was performed as follows. The obtained final polymer latex was filtered through a 300-mesh wire mesh, dried at 125 ° C., and the ratio of the coagulum remaining on the wire mesh to the polymer solid content was measured. Compared with the comparative example in which the nonionic surfactant was not added, in the examples and experimental examples in which the nonionic surfactant was added, the amount of coagulum was small, and when PTSM was used as the quaternizing agent, 1/10 or less. Produces a significant synergistic effect.
[0032]
[Table 1]

[0033]
Example 3 A 1% pulp slurry of LBKP having a beating degree measured according to JIS P8121 of 380 ml (CSF) was adjusted to pH 7.5. A predetermined amount of the latex obtained in Examples 1 and 2, Experimental Examples 1 to 3 and Comparative Examples 1 to 3 was added and mixed, and a sheet having a basis weight of 60 g / m ² was obtained with a square sheet machine. After pressing at m ² for 5 minutes, it was dried with a drum dryer at 120 ° C. for 2 minutes. The specific burst strength and the steech human size of the obtained sheet were measured based on JIS P8112 and JIS P8122, respectively, and the results shown in Table 2 were obtained. The neutralized salt type is not fixed in the neutral range and cannot exert its effect.
[0034]
[Table 2]

[0035]
Example 4 2.5% sulfuric acid band was added to 1% pulp slurry of LBKP beaten to 420 ml (C.S.F), and finally a predetermined amount of latex adjusted to pH 4.5 was added. A sheet was prepared under the same conditions as in Example 3 , the specific burst strength was measured, and the results shown in Table 3 were obtained.
[0036]
[Table 3]

[0037]
Example 5 Nopco 8034 (San Nopco) was added to and mixed with the polymer emulsions obtained in Experimental Example 1, Example 1, and Comparative Examples 1 and 2 as a defoaming agent with respect to the solid content. In accordance with “7.6 Adhesive Strength” of JIS A6203 “Polymer Dispersion for Cement”, 25 weights of the obtained polymer emulsion is added to 100 parts by weight of cement, 300 parts by weight of Toyoura standard sand and 50 parts by weight of water. Partially kneaded and applied to a mortar plate to obtain a test specimen. After curing for 14 days at a humidity of 65 ± 10% and a temperature of 20 ± 2 ° C., the adhesion strength was measured and the results shown in Table 4 were obtained.
[0038]
[Table 4]

[0039]
【The invention's effect】
In the present invention, since a ready-made polymer latex is used as the seed latex, the labor for adjusting the seed latex can be saved, the seed polymerization can be stably performed, the particle diameter of the obtained emulsion is uniform, and the storage stability is good. In particular, by performing cationization in the presence of a nonionic surfactant, the formation of coagulum can be suppressed to a very low level, and the cationization density on the surface is large. The polymer emulsion of the present invention has useful applications such as various admixtures and paper processing agents.

Claims (6)

After adding a nonionic surfactant to a seed polymer obtained by adding and polymerizing a monomer represented by the following general formula (1) to a synthetic rubber latex or a synthetic resin emulsion as a seed latex, A polymer emulsion with less coagulum, characterized by imparting high density cationicity to the surface of emulsion particles by quaternary ammonium salification with methyl paratoluenesulfonate as a quaternizing agent.

(Where R ₁ is H or CH ₃ , R ₂ is an alkylene group having 2 to 5 carbon atoms, R ₃ and R ₄ are independently H or an alkyl group having 1 to 5 carbon atoms, A is

R ₁ , R ₃ and R ₄ are selected in the range where the monomer is hardly soluble or insoluble in water. )   The polymer emulsion according to claim 1, wherein the seed polymer is obtained by adding and polymerizing an ethylenically unsaturated monomer copolymerizable with the monomer represented by the general formula (1) to the seed latex.   The polymer emulsion according to claim 1 or 2, wherein the synthetic rubber latex or synthetic resin emulsion is carboxy-modified. Formula (1) polymer emulsion of claim 3 addition amount of the monomer or synthetic rubber latex is a synthetic resin colloid equivalent value of the emulsion (absolute value) or more.   The nonionic surfactant is one or a mixture of polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene lauryl ether, its HLB is between 10 and 19, and its addition amount is a polymer emulsion The polymer emulsion according to any one of claims 1 to 4, which is 0.1 to 4% by weight based on the solid content of the polymer. Carboxyl-modified synthetic rubber latex or synthetic resin emulsion is used as a seed latex, and the seed latex is neutralized to pH 6 or higher, and then the monomer represented by the general formula (1) is at least a colloid equivalent value of the seed latex. after addition (absolute value) or more, the seed polymer obtained by radical polymerization and after addition of nonionic surface active agents, methyl p-toluenesulfonate is a quaternizing agent quaternary ammonium and chloride was added A method for producing a polymer emulsion, wherein the emulsion particle surface is imparted with high cationicity at a high density.

(Where R ₁ is H or CH ₃ , R ₂ is an alkylene group having 2 to 5 carbon atoms, R ₃ and R ₄ are independently H or an alkyl group having 1 to 5 carbon atoms, A is

R ₁ , R ₃ and R ₄ are selected in the range where the monomer is hardly soluble or insoluble in water. )