JPS62121629A - Aqueous dispersion stabilizer for fine powder - Google Patents

Abstract

PURPOSE:To avoid the formation of a hard cake during preservation, by preparing an aqueous dispersant containing a graft polymer prepared by reacting ligninsulfonic acid, acrylic acid and methacrylic acid in the presence of a polymerization initiator as an effective component. CONSTITUTION:Ligninsulfonic acid is reacted with acrylic acid, methacrylic acid or a mixture thereof in the presence of a polymerization initiator to form a salt of a graft polymer and an aqueous dispersion stabilizer for a fine powder containing said salt of the graft polymer as a useful component is prepared. The amount of ligninsulfonic acid is pref. set to 0.1-50pts.wt. of 1pt. of acrylic acid, methacrylic acid or the mixture thereof. As the polymerization initiator, peroxide is pref. and, especially, hydrogen peroxide and persulfate are pref. As the salt of the graft polymer, and alkali metal salt, an alkaline earth metal salt, and ammonium salt, etc. are pref.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は炭酸カルシウム、酸化チタン、顔料などの微
粉末の水系分散安定剤に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to an aqueous dispersion stabilizer of fine powder of calcium carbonate, titanium oxide, pigment, etc.

〔従来の技術〕[Conventional technology]

各種の産業分野において、上述の如き水難溶性または水
不溶性の微粉末を水中に分散させてなる水中分散体が広
く利用されている。この種の分散体において、分散剤を
加えないときは、一旦分散された微粉末が、これと水と
の比重の大小あるいは水に対する親和性の差により、非
常に短時間のうちに沈降したり浮いたりするといった種
々の現象を呈することとなる。一般には、微粉末の比重
の方が水のそれより大きいので、沈降するのがほとんど
である。BACKGROUND ART In various industrial fields, aqueous dispersions prepared by dispersing the above-mentioned sparingly water-soluble or water-insoluble fine powders in water are widely used. In this type of dispersion, if no dispersant is added, the fine powder once dispersed may settle in a very short time due to the difference in specific gravity between it and water or the affinity for water. This results in various phenomena such as floating. Generally, the specific gravity of fine powder is greater than that of water, so it mostly settles.

そこで、従来より、このような沈降現象を防止するため
に、分散剤として適宜の界面活性剤を加えて微粉末を水
中に安定に懸濁させる試みがなされてきた。この目的で
用いられてきた従来の分散剤は、いずれも微粉末の二次
粒子を一次粒子にはぐす作用と、はぐれた粒子がＩＧび
凝集するのを防ぐ作用とを有し、これら作用によって微
粉末の分散安定化を図るようにしたものである。Therefore, in order to prevent such a sedimentation phenomenon, attempts have been made to stably suspend fine powder in water by adding an appropriate surfactant as a dispersant. Conventional dispersants that have been used for this purpose all have the effect of separating the secondary particles of fine powder into primary particles and the effect of preventing the separated particles from IG and agglomeration. This is intended to stabilize the dispersion of fine powder.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかるに、このように分散安定化が図られた水中分散体
であっても、分散体自月は本来熱力学的に不安定なので
、これを長時間放置しておくと粉末粒子は最終的に沈降
する。このとき、分散剤によって分散安定化が図られた
微粒子はど細密充填に近い沈降物になるので、かたく再
分散しにくい沈澱物、つまりハードケーキをつくりやす
い。However, even with an aqueous dispersion that has been stabilized in this way, the dispersion itself is inherently thermodynamically unstable, so if it is left for a long time, the powder particles will eventually settle. do. At this time, the fine particles whose dispersion has been stabilized by the dispersant become a precipitate that is close to close packing, which tends to create a hard precipitate that is difficult to redisperse, that is, a hard cake.

これを要するに、従来の分散剤を用いて調製された水中
分散体は、その調製後比較的短！ＩＪＩのうちに使用す
るときは特に問題はないが、最終的に沈降してしまうよ
うな長期間の保存後に使用する場合にはハードケーキが
住成し、その再分１）父性が悪いため実用性に却って乏
しいイ）のとなってしまうという問題があった。The bottom line is that dispersions in water prepared using conventional dispersants are relatively short-lived after their preparation. There is no particular problem when using it during IJI, but if it is used after long-term storage where it will eventually settle, a hard cake will form and its redistribution 1) is not practical due to poor paternity. There was a problem that it ended up being (a), which was rather lacking in sex.

したがって、この発明は、ｌ：　ｉｔｄ　４ｊｌ来のも
のに較べて同等以上の分散効果を有するとともに、長期
保存の場合にも沈降物がハートケーキを生成しにくいよ
うな微粉末用の水系分散安定剤を提供することを目的と
する。Therefore, the present invention provides an aqueous dispersion stabilizer for fine powders which has a dispersion effect equal to or higher than that of the previous one and which is less likely to form a heart cake as a sediment even during long-term storage. The purpose is to provide

〔問題点を解決するための手段〕[Means for solving problems]

この発明者らは、上記目的を達成するために鋭意検討し
た結果、微粉末用の水系分散安定剤として、リグニンス
ルホン酸を重合開始剤の存在下でアクリル酸、メタクリ
ル酸またはそれらの混合物と反応させて得られるグラフ
ト重合体の塩を使用したときには、微粉末の分散性と分
散安定性との両特性に共に好結果が得られ、しかも長期
保存後の沈降物がハードケーキを生成しにくいものとな
って再分散性にも好結果が得られるものであることを見
い出し、この発明をなすに至った。As a result of extensive studies to achieve the above object, the inventors discovered that ligninsulfonic acid was reacted with acrylic acid, methacrylic acid, or a mixture thereof in the presence of a polymerization initiator as an aqueous dispersion stabilizer for fine powder. When using the graft polymer salt obtained by this method, good results were obtained in both the dispersibility and dispersion stability of the fine powder, and the sediment was less likely to form a hard cake after long-term storage. Therefore, they discovered that good results can be obtained in terms of redispersibility as well, leading to the creation of this invention.

すなわち、この発明は、リグニンスルホン酸を重合開始
剤の存在下でアクリル酸、メタクリル酸またはそれらの
混合物〔以下、（メタ）アクリル酸という〕と反応させ
て得られるグラフト重合体の塩を有効成分とする微粉末
の水系分散安定剤に関するものである。That is, this invention uses as an active ingredient a salt of a graft polymer obtained by reacting ligninsulfonic acid with acrylic acid, methacrylic acid, or a mixture thereof [hereinafter referred to as (meth)acrylic acid] in the presence of a polymerization initiator. This invention relates to a fine powder aqueous dispersion stabilizer.

〔発明の構成・作用〕[Structure and operation of the invention]

この発明の水系分散安定剤は、木材からセルロースを分
離する過程で得られるリグニンスルホン酸を、一般に水
中において、重合開始剤としての過酸化物の存在下で（
メタ）アクリル酸と反応させて得られるグラフト重合体
の塩を有効成分とするものである。The aqueous dispersion stabilizer of the present invention is generally produced by converting lignin sulfonic acid obtained in the process of separating cellulose from wood into water in the presence of peroxide as a polymerization initiator (
The active ingredient is a salt of a graft polymer obtained by reacting with meth)acrylic acid.

リグニンスルホン酸はいかなる木材から得られるもので
もこの発明の水系分散安定剤の原料として有用である。Lignosulfonic acid obtained from any wood is useful as a raw material for the aqueous dispersion stabilizer of the present invention.

このリグニンスルボン酸を（メタ）アクリル酸とグラフ
ト重合させる際の両者の使用割合としては、後者〔（メ
タ）アクリル酸〕　１重量部に対する前者（リグニンス
ルポン酸）の量が０．１〜５０重量部、好ましくは０．
４〜２０重量部となるようにするのがよい。これらの範
囲内に設定したときに、この発明の１−１的を達成する
に特に好適な水系分散安定剤を得ることができる。When graft polymerizing this lignin sulfonic acid with (meth)acrylic acid, the ratio of the former (lignin sulfonic acid) to 1 part by weight of the latter [(meth)acrylic acid] is from 0.1 to 1. 50 parts by weight, preferably 0.
The amount is preferably 4 to 20 parts by weight. When the content is set within these ranges, it is possible to obtain an aqueous dispersion stabilizer particularly suitable for achieving the object 1-1 of the present invention.

重合開始剤としては過酸化物が好ましく、とくに過酸化
水素、過硫酸塩やクメンヒドロペルオキシドなどの有機
過酸化物が好ましい。もちろん、これらの過酸化物にの
み限定されるものではない。As the polymerization initiator, peroxides are preferred, and organic peroxides such as hydrogen peroxide, persulfates, and cumene hydroperoxide are particularly preferred. Of course, it is not limited to these peroxides.

重合開始剤のりゲニンスルホン酸および（メタ）アクリ
ル酸に対する添加量は、通常の重合反応に用いられる量
であればよく、その量によって重合度を適宜変えればよ
い。通常は０．１〜５重量％の範囲で用いられる。The amount added to the polymerization initiators, geninsulfonic acid and (meth)acrylic acid, may be any amount that is used in a normal polymerization reaction, and the degree of polymerization may be changed as appropriate depending on the amount. It is usually used in a range of 0.1 to 5% by weight.

このようなグラフト重合にて得られる反応物には、リグ
ニンスルホン酸に（メタ）アクリル酸がグラフト重合し
たグラフト重合体が含まれ、一部未反応のリグニンスル
ホン酸や（メタ）アクリル酸の単独重合物が含まれてく
ることもあるが、この発明においては、これらの未反応
物や単独重合物を分離除去する必要は特にない。The reactants obtained by such graft polymerization include a graft polymer in which (meth)acrylic acid is grafted onto ligninsulfonic acid, and some unreacted ligninsulfonic acid and (meth)acrylic acid alone. Although polymers may be included, in this invention there is no particular need to separate and remove these unreacted products and homopolymers.

この発明の水系分散安定剤においては、このようなグラ
フト重合体を塩のかたちとして使用する。In the aqueous dispersion stabilizer of the present invention, such a graft polymer is used in the form of a salt.

この塩とする手段は任意であり、たとえばグラフト重合
反応を水中で行う場合は所要のアルカリを反応前に加え
るかあるいは反応後または反応前後に加えて中和すれば
よい。塩としては、カリウム塩、ナトリウム塩のような
アルカリ金属塩、マグネシウム塩、カルシウム塩、バリ
ウム塩のようなアルカリ土類金属塩、アンモ三つム塩、
低級アミン塩などがある。低級アミン塩としては、メチ
ルアミン、エチルアミン、ブ１′１ビル“〆ミンなどの
イＩ（級アルキルアミン塩や、モノエタノ−ルアミン、
トリエタノールアミンなどの“？ルカノールアミン塩が
好ましいものとして用いられる。The means for forming this salt may be arbitrary. For example, when the graft polymerization reaction is carried out in water, the necessary alkali may be added before the reaction, or after or before or after the reaction to neutralize it. Salts include alkali metal salts such as potassium salts and sodium salts, alkaline earth metal salts such as magnesium salts, calcium salts, and barium salts, ammonium salts,
These include lower amine salts. Examples of lower amine salts include methylamine, ethylamine, butylamine, etc. (lower alkylamine salts, monoethanolamine,
A ``lukanolamine salt'' such as triethanolamine is preferably used.

この発明の分１）１／安定剤の使用にあたって番ま、分
散安定剤を全系（微粉末子水）に対し０．０１〜１０重
量％の割合で使用すればよく、好ましくは０゜０５〜２
．５重量％の割合で添加するのがよい。添加量が少なけ
れば効果が小さく、多ずぎでも効果が一定で経済的に不
利である。Part 1) of this invention 1/When using the stabilizer, the dispersion stabilizer may be used in a proportion of 0.01 to 10% by weight based on the entire system (fine powdered water), preferably 0.05% by weight. ~2
．． It is preferable to add it in a proportion of 5% by weight. If the amount added is small, the effect is small, and if the amount is added, the effect remains constant, which is economically disadvantageous.

この発明の分散安定剤は無機および有機のいずれの微粉
末に対しても有効である。無機微粉末としては、カオリ
ン、ケイ酸アルミニウム、クレー、タルク、ライ力、゛
アスベスト粉、ケイ酸カルシウム、セリサイト、ヘント
ナイト、炭酸カルシウム、炭酸マグネシウム、炭酸バリ
ウム、ドロマイト、硫酸カルシウム、硫酸バリウム、マ
グネシア、アルミナ、三酸化アンチモン、酸化チタン、
酸化鉄、酸化亜鉛、ホワイトカーボン、カーボンブラッ
ク、けいそう土、水酸化アルミニウム、水酸化マグネシ
ウム、水酸化鉄、炭化ケイ素、窒化ケイ素、窒化ホウ素
、ジルコニア、チタン酸バリウム、サチンホワイト、紺
青、群青などがある。有機微粉末としては、不溶性アゾ
染料、アゾ系分散染料、アントラキノン系分散染料、ス
レン染料、フタルシアニン系顔料、レーキ顔料、ペリレ
ン顔料、ジオキサジン顔料、キナクリドン顔料、ポリ酢
酸ビニル、酢酸ビニル−アクリル樹脂、エチレン−酢酸
ビニル樹脂、アクリル樹脂、スチレン−ブタジェンゴム
などがある。The dispersion stabilizer of this invention is effective for both inorganic and organic fine powders. Inorganic fine powders include kaolin, aluminum silicate, clay, talc, lye, asbestos powder, calcium silicate, sericite, hentonite, calcium carbonate, magnesium carbonate, barium carbonate, dolomite, calcium sulfate, barium sulfate, and magnesia. , alumina, antimony trioxide, titanium oxide,
Iron oxide, zinc oxide, white carbon, carbon black, diatomaceous earth, aluminum hydroxide, magnesium hydroxide, iron hydroxide, silicon carbide, silicon nitride, boron nitride, zirconia, barium titanate, satin white, navy blue, ultramarine, etc. There is. Organic fine powders include insoluble azo dyes, azo disperse dyes, anthraquinone disperse dyes, threne dyes, phthalcyanine pigments, lake pigments, perylene pigments, dioxazine pigments, quinacridone pigments, polyvinyl acetate, vinyl acetate-acrylic resins, Examples include ethylene-vinyl acetate resin, acrylic resin, and styrene-butadiene rubber.

これら微粉末の粒子径は、その種類により広範囲にわた
るが、一般には平均粒子径が０．１〜１゜０μｍの範囲
にあるのがこの発明の前記分散安定剤の効果をより良く
発揮させるうえで望ましい。The particle size of these fine powders varies over a wide range depending on the type, but generally the average particle size is in the range of 0.1 to 1.0 μm in order to better exhibit the effect of the dispersion stabilizer of the present invention. desirable.

また、この発明の分散安定剤を用いて安定な水中分散体
を得るための上記微粉末の濃度に関しても、その種類に
よりやはり大きく異なるものであるが、一般には水中で
の濃度が０．５〜８０重量％の範囲が適当である。Furthermore, the concentration of the fine powder used to obtain a stable aqueous dispersion using the dispersion stabilizer of the present invention also varies greatly depending on the type of powder, but generally the concentration in water is 0.5 to 0. A range of 80% by weight is suitable.

この発明の分散安定剤を用い’Ｃ＋−を的とする水中分
散体を調製するにあたっては、ア１ライター、サンドミ
ル、三本ロール、）トールミルなどの各種の分散機器を
用いて、これに所定祉の水、微粉末および前記分散安定
剤を投入し、所定時間粉砕。When preparing an aqueous dispersion targeting 'C+- using the dispersion stabilizer of the present invention, various types of dispersion equipment such as an alliter, a sand mill, a three-roll mill, and a tall mill are used to prepare the dispersion using a predetermined cleaning method. Add water, fine powder, and the dispersion stabilizer, and grind for a predetermined time.

混合すればよい。分散安定剤の投入時点は、これらの機
器で二次粒子を粉砕する工程の前であっても、また上記
工程後であってもよい。Just mix. The dispersion stabilizer may be added before the step of pulverizing the secondary particles with these devices, or after the above step.

なお、上記の調製に際し、この発明の前記分散安定剤と
ともに、他の水系分散剤、たとえばアニオン性、ノニオ
ン性の界面活性剤であるオレフィン−マレイン酸共重合
物の塩、（メタ）アクリル酸重合物の塩、ナフタレンス
ルホン酸ホルムアルデヒド縮金物の塩、縮合リン酸塩、
ポリオキシエチレンオレイルエーテル、ポリオキシエチ
レンソルビタンモノオレー１・などを併用するようにし
てもよい。この併用により、微粉末の分散性９分散安定
性および沈降物の再分散性に一層良好な結果が得られる
こともある。In addition, in the above preparation, in addition to the dispersion stabilizer of the present invention, other aqueous dispersants, such as salts of olefin-maleic acid copolymers that are anionic and nonionic surfactants, (meth)acrylic acid polymerization salts of naphthalene sulfonic acid formaldehyde condensates, condensed phosphates,
Polyoxyethylene oleyl ether, polyoxyethylene sorbitan monoole 1, etc. may be used in combination. By using this combination, better results may be obtained in terms of dispersion stability of fine powder and redispersibility of sediment.

〔発明の効果〕〔Effect of the invention〕

以上のように、この発明の微粉末の水系分散安定剤は、
前記グラフト重合体の塩を有効成分としたことにより、
微粉末の分散性２分散安定性にすぐれるだけでなく、長
期保存後に沈降してもその沈降物がソフトで再分散性の
良い水中分散体の調製を可能とする。As described above, the fine powder aqueous dispersion stabilizer of the present invention is
By using the salt of the graft polymer as an active ingredient,
Dispersibility of fine powder 2 Not only does it have excellent dispersion stability, but even if it settles after long-term storage, the precipitate is soft, making it possible to prepare an aqueous dispersion with good redispersibility.

〔実施例〕〔Example〕

以下に、この発明の実施例を記載してより具体的に説明
する。なお、以下の実施例および比較例で調製した水中
分散体の分散安定性および再分散性は、下記の方法で測
定評価した。EXAMPLES Below, examples of the present invention will be described in more detail. The dispersion stability and redispersibility of the water dispersions prepared in the following Examples and Comparative Examples were measured and evaluated using the following methods.

〈分散安定性〉 水中分散体の調製後、速やかに５０　ｍ　Ｉｔの目盛付
き乳化試験管に入れ、２５℃の恒温室に静置し、２４時
間後の分散状態を観察して、以下の如く評価した。<Dispersion stability> After preparing the dispersion in water, immediately put it into a 50 m It graduated emulsification test tube, leave it in a constant temperature room at 25°C, observe the dispersion state after 24 hours, and evaluate the dispersion as follows. evaluated.

○：微粉末が全く沈降していない △：微粉末がわずかに沈降している ×：微粉末が完全に沈険し゛（いる 〈再分散性〉 水中分散体の調製後、速やかに５０ｍ１の目盛付き乳化
試験管に入れ、２５°Ｃの恒温室に静置し、３０日後の
沈降物の硬さや再分散性を調べ、以下の如く評価した。○: The fine powder has not settled at all △: The fine powder has settled slightly ×: The fine powder has completely settled (Redispersibility) Immediately after preparing the dispersion in water, immediately The mixture was placed in an emulsification test tube and left to stand in a constant temperature room at 25°C, and after 30 days, the hardness and redispersibility of the sediment were examined and evaluated as follows.

Ｏ：水を攪拌すると分散する △：軟らかくてスパーチルでつつくと容易に崩れる ×：硬くてスパーチルでつついても容易に崩れない なおまた、以下の実施例では、この発明の水系分散安定
剤として、下記の合成例１〜６によって合成したものを
用いたが、特許請求の範囲で規定されているものである
限り、この発明の水系分散安定剤がこれらの合成例によ
って得られるものにのみ限定されないことはいうまでも
ない。O: Disperses when water is stirred △: Soft and easily crumbles when poked with a spatula ×: Hard and does not crumble easily when poked with a spatula In addition, in the following examples, as the aqueous dispersion stabilizer of the present invention, Although those synthesized by the following Synthesis Examples 1 to 6 were used, the aqueous dispersion stabilizer of this invention is not limited to those obtained by these synthesis examples as long as it is specified in the claims. Needless to say.

〈合成例１〉 リグニンスルホン酸１（）０車間部を水１５０重量部と
ともに、攪拌機、温度旧およびコンデンサ一つき反応器
に入れ、さらにアクリル酸６０重量部を加え、混合物を
約３０°Ｃに加熱した。次いで１０容量％の過酸化水素
水２重量部を攪拌下に加えたところ、発熱反応が起こっ
て、温度は８０℃に達した。この温度で５分間反応を続
け、さらに加熱して９５℃に１０分間保持して反応を完
了した。反応混合物の中和価を測定し、中和当量の水酸
化ナトリウムを４８重量％の水溶液として加え、中和を
行って、グラフト重合体の塩を含むこの発明の分散安定
剤Ａを得た。<Synthesis Example 1> Lininsulfonic acid 1()0 was placed in a reactor equipped with a stirrer, a temperature regulator and a condenser together with 150 parts by weight of water, 60 parts by weight of acrylic acid was added, and the mixture was heated to approximately 30°C. Heated. Then, when 2 parts by weight of 10% by volume hydrogen peroxide solution was added with stirring, an exothermic reaction occurred and the temperature reached 80°C. The reaction was continued at this temperature for 5 minutes, and then heated and maintained at 95° C. for 10 minutes to complete the reaction. The neutralization value of the reaction mixture was measured, and a neutralization equivalent of sodium hydroxide was added as a 48% by weight aqueous solution to perform neutralization, thereby obtaining the dispersion stabilizer A of the present invention containing the salt of the graft polymer.

〈合成例２〉 リグニンスルホン酸１００重量部と２００重量部の水と
を合成例１と同様の反応器に入れ、さらに１００重量部
のアクリル酸を加えて約３０℃に加熱シ、クメンヒドロ
ペルオキシド２重量部を加えた。発熱反応が起り温度は
８０℃に達した。さらに昇温せしめて９５℃に１０分間
保持して反応を完結した。得られた混合物の中和価を測
定し、中和当量のアンモニア水溶液（２８重量％）で中
和して、グラフト重合体の塩を含むこの発明の分散安定
剤Ｂを得た。<Synthesis Example 2> 100 parts by weight of ligninsulfonic acid and 200 parts by weight of water were placed in the same reactor as in Synthesis Example 1, and further 100 parts by weight of acrylic acid was added and heated to about 30°C to form cumene hydroperoxide. 2 parts by weight were added. An exothermic reaction occurred and the temperature reached 80°C. The temperature was further raised and maintained at 95°C for 10 minutes to complete the reaction. The neutralization value of the resulting mixture was measured, and the mixture was neutralized with an aqueous ammonia solution (28% by weight) in a neutralization equivalent amount to obtain a dispersion stabilizer B of the present invention containing a salt of a graft polymer.

〈合成例３〉 合成例１と同様の手法にて、リグニンスルホン酸にアク
リル酸をグラフト重合させた。ただし、アクリル酸の使
用量を４０重量部に変更し、かつ過酸化水素水の代わり
にクメンヒドロペルオキシド０．３重量部を用いた。そ
の他の反応条件は合成例１と同様であった。重合後、水
酸化ナトリウムの４８重景％水溶液で中和して、グラフ
ト重合体の塩を含むこの発明の分１）に安定剤Ｃを得た
。<Synthesis Example 3> In the same manner as in Synthesis Example 1, acrylic acid was graft-polymerized to ligninsulfonic acid. However, the amount of acrylic acid used was changed to 40 parts by weight, and 0.3 parts by weight of cumene hydroperoxide was used instead of hydrogen peroxide solution. Other reaction conditions were the same as in Synthesis Example 1. After polymerization, it was neutralized with a 48% aqueous solution of sodium hydroxide to obtain stabilizer C in part 1) of this invention containing the salt of the graft polymer.

〈合成例４〉 合成例１の方法を繰り返した。ただし、アクリル酸に代
えてメタクリル酸３０重量部を使用し、これを加えたと
きの加熱温度を４０℃とした。１０容量％の過酸化水素
水２重量部を加えたところ、発熱反応により反応混合物
は６５℃に達した。この温度に５分間保持したのち、さ
らに加熱して９５℃に１０分間保持して反応を完結した
。アンモニアの２８重量％水溶液で中和して、グラフト
重合体の塩を含むこの発明の分散安定剤りを得た。<Synthesis Example 4> The method of Synthesis Example 1 was repeated. However, 30 parts by weight of methacrylic acid was used instead of acrylic acid, and the heating temperature when this was added was 40°C. When 2 parts by weight of 10% by volume hydrogen peroxide solution was added, the reaction mixture reached 65°C due to an exothermic reaction. After maintaining this temperature for 5 minutes, it was further heated and maintained at 95° C. for 10 minutes to complete the reaction. Neutralization was carried out with a 28% by weight aqueous solution of ammonia to obtain a dispersion stabilizer of the present invention containing a salt of the graft polymer.

〈合成例５〉 合成例１の方法を繰り返した。ただし、アクリル酸６０
重量部の代わりにアクリル酸５５重量部とメタクリル酸
５５重量部とを使用し、かつ１０容量％の過酸化水素水
の使用量を４重量部とした。<Synthesis Example 5> The method of Synthesis Example 1 was repeated. However, acrylic acid 60
55 parts by weight of acrylic acid and 55 parts by weight of methacrylic acid were used instead of parts by weight, and the amount of 10% by volume hydrogen peroxide solution used was 4 parts by weight.

過酸化水素水を加えたところで発熱反応により反応混合
物は７０℃に達した。この温度に５分間保持したのち、
９５℃に加熱し１０分間保持して重合を完結した。重合
後、４８重量％水酸化ナトリウム水溶液で中和して、グ
ラフト重合体の塩を含むこの発明の分散安定剤Ｅを得た
。When the hydrogen peroxide solution was added, the reaction mixture reached 70°C due to an exothermic reaction. After maintaining this temperature for 5 minutes,
Polymerization was completed by heating to 95°C and holding for 10 minutes. After the polymerization, the mixture was neutralized with a 48% by weight aqueous sodium hydroxide solution to obtain a dispersion stabilizer E of the present invention containing a salt of the graft polymer.

〈合成例６〉 合成例１の方法を繰り返した。ただし、アクリル酸６０
重量部の代わりにアクリル酸１０重量部とメタクリル酸
１０重量部とを使用し、かつ１０容量％の過酸化水素水
の使用量を３重量部とした。<Synthesis Example 6> The method of Synthesis Example 1 was repeated. However, acrylic acid 60
Instead of parts by weight, 10 parts by weight of acrylic acid and 10 parts by weight of methacrylic acid were used, and the amount of 10% by volume hydrogen peroxide solution used was 3 parts by weight.

過酸化水素水を加えたところで発熱反応により反応混合
物は７５℃に達した。この温度に５分間保持したのち、
９５℃に加熱し１０分間保持して重合を完結した。重合
後、４０重量％水酸化カリウム水溶液で中和して、グラ
フト重合体の塩を含むこの発明の分散安定剤Ｉ？を得た
。When the hydrogen peroxide solution was added, the reaction mixture reached 75° C. due to an exothermic reaction. After maintaining this temperature for 5 minutes,
Polymerization was completed by heating to 95°C and holding for 10 minutes. After the polymerization, it is neutralized with a 40% by weight aqueous potassium hydroxide solution to obtain the dispersion stabilizer I? of the present invention containing the graft polymer salt. I got it.

なお、以−ヒの合成例１〜６で得られた各分散安定剤水
溶液は、１０５°Ｃで乾燥した乾燥減量から、その有効
分１′農度を求めておき、これをもとに以下の実施例に
おいて水中分散体中の分散安定剤有効分の濃度を所定値
に設定した。In addition, each dispersion stabilizer aqueous solution obtained in Synthesis Examples 1 to 6 below was dried at 105°C, and its effective content 1' degree was determined from the drying loss, and based on this, the following In this example, the concentration of the effective dispersion stabilizer in the water dispersion was set to a predetermined value.

実施例１ 微粉末として平均粒子径が０．３　、Ｉｌｍの酸化チタ
ン（Ｒ−８２（１石原産業（掬〕を用い、かつ分散安定
剤として前記分散安定剤Ａ　−１・”を用いて、分散安
定剤カ用重量％、微粉末が１０重量％の濃度となるよう
に所定量の水、分散安定剤および微粉末を混合し、これ
をサンドミル〔五十嵐機械製造■製〕に投入し、５時間
粉砕混合することにより、この発明に係る水中分散体を
ｆｉｔ！、ｌ製した。Example 1 Using Ilm titanium oxide (R-82 (1) Ishihara Sangyo (Kiki) with an average particle diameter of 0.3 as a fine powder, and using the dispersion stabilizer A-1 as a dispersion stabilizer, A predetermined amount of water, a dispersion stabilizer, and a fine powder were mixed so that the concentration of the fine powder was 10% by weight, and this was put into a sand mill (manufactured by Igarashi Machinery Co., Ltd.). The aqueous dispersion according to the present invention was prepared by time-grinding and mixing.

比較例１ 分散安定剤として、分散安定剤Ｇ（平均分子量５．００
０のポリアクリル酸すトリウム塩）、分散安定剤Ｈ（リ
グニンスルボン酸ナトリウム塩）および分散安定剤Ｉ　
（ヘキサメタリン酸ナトリウム塩）を用いた以外は、実
施例１と全く同様にして比較用の水中分散体を調製した
。Comparative Example 1 As a dispersion stabilizer, dispersion stabilizer G (average molecular weight 5.00
0), dispersion stabilizer H (lignin sulfonic acid sodium salt), and dispersion stabilizer I
A comparative aqueous dispersion was prepared in exactly the same manner as in Example 1, except that (hexametaphosphate sodium salt) was used.

上記の実施例１および比較例１の水中分散体の分散安定
性および再分散性を調べた結果は、つぎの第１表に示さ
れるとおりであった。The results of examining the dispersion stability and redispersibility of the aqueous dispersions of Example 1 and Comparative Example 1 were as shown in Table 1 below.

実施例２ 微粉末として平均粒子径２μｍの重質炭酸カルシウムを
用い、かつ分散安定剤として前記分散安定剤Ａ−Ｆを用
いて、分散安定剤が第２表に記載の濃度、微粉末が１０
重車間の濃度となるように所定量の水、分散安定剤お、
ｈび微粉末を混合し、これをホモミキサーに投入し、２
．ｌｌ１００ｒｐ。Example 2 Heavy calcium carbonate with an average particle diameter of 2 μm was used as the fine powder, and the above-mentioned dispersion stabilizers A-F were used as the dispersion stabilizer, the concentration of the dispersion stabilizer was as shown in Table 2, and the fine powder was
Add a predetermined amount of water, dispersion stabilizer, and
Mix fine powder of hives and put it into a homo mixer, 2
．． ll100rp.

１０分の条件で混合することにより、この発明に係る水
中分散体を調製した。An aqueous dispersion according to the invention was prepared by mixing for 10 minutes.

比較例２ 分散安定剤として、分散安定剤、１　（平均分子量１５
．０００のオクテン−無水マレイン酸共重合物のナトリ
ウム塩）を用い、この分散安定剤が第２表に記載の濃度
となるようにした以外は、実施例２と全く同様にして比
較用の水中分散体を調製した。Comparative Example 2 As a dispersion stabilizer, dispersion stabilizer, 1 (average molecular weight 15
．． An aqueous dispersion for comparison was carried out in exactly the same manner as in Example 2, except that the concentration of the dispersion stabilizer was as shown in Table 2. body was prepared.

上記の実施例２および比較例２の水中分散体の分散安定
性および再分散性を調べた結果は、っぎの第２表に示さ
れるとおりであった。The results of examining the dispersion stability and redispersibility of the aqueous dispersions of Example 2 and Comparative Example 2 were as shown in Table 2 below.

第２表 実施例３ 微粉末として平均粒子径０．２μｍの水酸化マグネシウ
ム粉末を用い、かつ分散安定剤として前記分散安定剤Ａ
−Ｆを用いて、分散安定剤が第３表に記載の濃度、微粉
末が１０重量％の濃度となるように所定量の水、分散安
定剤および微粉末を混合し、これをホモミキサーに投入
し、２．００Ｏｒｐｍ、１０分の条件で混合するごとに
より、この発明に係る水中分散体を調製した。Table 2 Example 3 Magnesium hydroxide powder with an average particle size of 0.2 μm was used as the fine powder, and the dispersion stabilizer A was used as the dispersion stabilizer.
-F, mix a predetermined amount of water, a dispersion stabilizer, and a fine powder so that the concentration of the dispersion stabilizer is as shown in Table 3 and the concentration of the fine powder is 10% by weight, and add this to a homomixer. An aqueous dispersion according to the present invention was prepared by adding the following ingredients and mixing each time under the conditions of 2.00 rpm and 10 minutes.

比較例３ 分散安定剤として、比較例１でポした分散安定剤Ｇを用
い、この分散安定剤が第３表に記載の濃度となるように
した以外は、実施例３と全く同様にして比較用の水中分
散体を調製した。　　−上記の実施例３お、Ｌび比較例
３の水中分散体の分散安定性および再分散性を調べた結
果は、つぎの第３表に示されるとおりであった。Comparative Example 3 Comparison was made in exactly the same manner as in Example 3, except that the dispersion stabilizer G used in Comparative Example 1 was used as the dispersion stabilizer, and the concentration of the dispersion stabilizer was as shown in Table 3. A dispersion in water was prepared. - The results of examining the dispersion stability and redispersibility of the aqueous dispersions of Example 3 and Comparative Example 3 above are as shown in Table 3 below.

第３表 実施例４ 微粉末としてカーボンブラック〔ファーネスブラックＭ
Ａ−１００：三菱化成工業■〕およびアゾ系分散染料原
末（分散剤を含まない原末であり、下記の構造式を有す
るもの）を用い、この微粉末の濃度および分散安定剤の
濃度を実施例１と同じにしてかつ実施例１と全く同様の
方法にて水中分散体を得た。Table 3 Example 4 Carbon black as fine powder [Furnace Black M
A-100: Mitsubishi Chemical Industries ■] and azo disperse dye bulk powder (a bulk powder that does not contain a dispersant and has the structural formula below), and the concentration of this fine powder and the concentration of the dispersion stabilizer were determined. An aqueous dispersion was obtained in the same manner as in Example 1 and in exactly the same manner as in Example 1.

〈アゾ系分散染料原末の構造式〉 ＣＨ２ 上記実施例４の水中分散体の分散安定性および再分散性
を調べた結果は、つぎの第４表に示されるとおりであっ
た。<Structural formula of azo disperse dye raw powder> CH2 The results of examining the dispersion stability and redispersibility of the aqueous dispersion of Example 4 were as shown in Table 4 below.

に、この発明の分散安定剤は各種微粉末の水系分散安定
剤として非常にすぐれた効果を発揮するものであること
が判る。Furthermore, it can be seen that the dispersion stabilizer of the present invention exhibits excellent effects as an aqueous dispersion stabilizer for various fine powders.

Claims (4)

【特許請求の範囲】[Claims] （１）リグニンスルホン酸を重合開始剤の存在下でアク
リル酸、メタクリル酸またはそれらの混合物と反応させ
て得られるグラフト重合体の塩を有効成分とする微粉末
の水系分散安定剤。(1) A fine powder aqueous dispersion stabilizer whose active ingredient is a salt of a graft polymer obtained by reacting ligninsulfonic acid with acrylic acid, methacrylic acid, or a mixture thereof in the presence of a polymerization initiator. （２）アクリル酸、メタクリル酸またはそれらの混合物
に対するリグニンスルホン酸の量が、前者１重量部に対
し、後者が０．１〜５０重量部である特許請求の範囲第
（１）項記載の微粉末の水系分散安定剤。(2) The amount of lignin sulfonic acid based on acrylic acid, methacrylic acid, or a mixture thereof is 0.1 to 50 parts by weight per 1 part by weight of the former. Powdered aqueous dispersion stabilizer. （３）重合開始剤が過酸化物である特許請求の範囲第（
１）項または第（２）項記載の微粉末の水系分散安定剤
。(3) The polymerization initiator is a peroxide (
The fine powder aqueous dispersion stabilizer according to item 1) or item (2). （４）グラフト重合体の塩がアルカリ金属塩、アルカリ
土類金属塩、アンモニウム塩または低級アミン塩である
特許請求の範囲第（１）〜（３）項のいずれかに記載の
微粉末の水系分散安定剤。(4) The aqueous fine powder according to any one of claims 1 to 3, wherein the salt of the graft polymer is an alkali metal salt, an alkaline earth metal salt, an ammonium salt, or a lower amine salt. Dispersion stabilizer.