JP4080105B2 - Surfactant composition for emulsion polymerization - Google Patents

Description

【０００８】
R²及びR³はそれぞれ１価の脂肪族炭化水素基、A¹, A², A³及びA⁴はそれぞれ炭素数２〜４のアルキレン基、p, q及びr はそれぞれアルキレンオキサイドの平均付加モル数を示す１〜50の数、s はアルキレンオキサイドの平均付加モル数を示す０〜50の数、M¹, M²及びM³はそれぞれ１価のカチオンを示し、p 個のA¹、q 個のA²、r 個のA³、s 個のA⁴は同一でも異なっていてもよい。）
【０００９】
【発明の実施の形態】
本発明の(a) 成分は、一般式（Ｉ）で表され、ＣＭＣが 0.005〜0.1molＬ^-1、好ましくは 0.008〜0.06 molＬ^-1の範囲にある化合物であり、単独でも２種以上を併用してもよい。また(b) 成分は、一般式(II)で表され、ＣＭＣが１×10^-5〜0.02 molＬ^-1、好ましくは 0.001〜0.01 molＬ^-1の範囲にある化合物であり、単独でも２種以上を併用してもよい。
なお本発明において、ＣＭＣは電気伝導度滴定法によって測定される値である。
【００１０】
一般式（Ｉ）及び(II)において、R¹は -O-(A⁴O)_s - が好ましく、特にA⁴が炭素数３〜４のアルキレン基であるものが好ましい。R²は炭素数10〜24、特に12〜16の直鎖又は分岐鎖のアルキル基が好ましい。R³は炭素数10〜24、特に11〜18の直鎖又は分岐鎖のアルキル基が好ましい。A¹, A²及びA³はエチレン基又はプロピレン基が好ましい。また２種以上のアルキレンオキサイドが付加する場合は、ランダム付加、ブロック付加のいずれでも良い。また両者の付加方法を組み合わせても良い。p, q, r 及びs は３〜30の数が好ましい。M¹, M²及びM³はナトリウム、カリウム等のアルカリ金属；アンモニウム；アルカノールアミン等のアミンが好ましい。
【００１１】
一般式（Ｉ）で表される化合物の中で特に好ましいものは、一般式(III) で表される化合物である。
【００１２】
M¹SO₃-O-(EO)_p-(A⁵O)_s-(EO)_q-SO₃M² (III)
（式中、M¹, M², p, q及びs は前記の意味を示し、EOはオキシエチレン基、A⁵はプロピレン基又はブチレン基を示す。）
一般式（Ｉ）で表される化合物は、例えば、ポリアルキレングリコール、長鎖アルキル基を有する１級アミン又は高級脂肪酸アミドにエチレンオキサイド、プロピレンオキサイド等のアルキレンオキサイドを付加した後、SO₃ ガス等のスルホン化剤で硫酸化し、NaOH等で中和することにより製造することができる。
【００１３】
一般式(II)で表される化合物は、例えば、脂肪族１価アルコールにエチレンオキサイド、プロピレンオキサイド等のアルキレンオキサイドを付加した後、SO₃ ガス等のスルホン化剤で硫酸化し、NaOH等で中和することにより製造することができる。
【００１４】
本発明の組成物中の(a) 成分と(b) 成分の配合割合は、モル比で (a)／(b) ＝５／95〜75／25、好ましくは10／90〜50／50である。 (a)／(b) が５／95未満であるとエマルジョンの粘度が高くなり、また機械的安定性も十分ではない。75／25を超えると粒径が大きくなりすぎ、また重合安定性、機械的安定性も十分ではない。
【００１５】
本発明の界面活性剤組成物を用いて乳化重合を行い得る単量体の具体例を挙げれば、スチレン、αーメチルスチレン、クロロスチレン等の芳香族ビニル単量体：アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル等のアクリル酸エステル類：メタクリル酸メチル、メタクリル酸エチル等のメタクリル酸エステル類：塩化ビニル、臭化ビニル、塩化ビニリデン等のハロゲン化ビニル及びハロゲン化ビニリデン類：酢酸ビニル、プロピオン酸ビニル等のビニルエステル類：アクリロニトリル、メタクリロニトリル等のニトリル類：ブタジエン、イソプレン等の共役ジエン類等である。これらの単量体は単独でも、２種以上を併用してもよい。
本発明の界面活性剤組成物は単量体100 重量部に対して0.1 〜20重量部、特に 0.5〜５重量部の範囲で用いるのが好ましい。
【００１６】
本発明の界面活性剤組成物は、ポリオキシエチレン（エチレンオキサイド付加モル数０〜100)アルキル又はアルケニル（アルキル又はアルケニル基の炭素数12〜24）エーテル等の非イオン界面活性剤と併用することもできる。更に水溶性保護コロイド等を併用することもできる。
【００１７】
本発明の界面活性剤組成物を用いる乳化重合条件には特に制限がなく、モノマーの量は全系に対して20〜70重量％、特に40〜50重量％が好ましい。またモノマー滴下法、モノマー一括仕込み法、プレエマルジョン法等のいずれの乳化重合法にも用いることができる。
【００１８】
【実施例】
実施例１〜11、比較例１〜８
(a) 成分として下記(a-1) 〜(a-9) 、(b) 成分として下記(b-1) 〜(b-4) を用い、表１に示す配合割合で本発明の界面活性剤組成物、及び比較の界面活性剤組成物を製造した。
【００１９】
【化３】

【００２０】
(b-1) ： C₁₂H₂₅O(CH₂CH₂O)₁₈SO₃Na ＣＭＣ 0.0046molＬ^-1
(b-2) ： C₁₄H₂₉O(CH₂CH₂O)₁₈SO₃Na ＣＭＣ 0.0012molＬ^-1
(b-3) ： C₁₂H₂₅O(CH₂CH₂O)₁₂SO₃Na ＣＭＣ 0.004 molＬ^-1
【００２１】
【化４】

【００２２】
ここでＣＭＣは下記方法により測定した。
【００２３】
＜ＣＭＣの測定法＞
100mLの蒸留水をビーカーにとり、攪拌しながら電気伝導度を測定した(電気伝導度計は東亜電波工業（株）CM-20S型、セルCG-511B)。あらかじめ所定濃度に調整した界面活性剤溶液を0.2mL ずつビーカー内に滴下し、滴下するごとに電気伝導度を読みとった。滴定液の界面活性剤濃度をｘ molＬ^-1、滴下した滴定液の量をｙmLとすると、ビーカー内の溶液中の界面活性剤濃度Ｃは、Ｃ＝ｘ・ｙ／(100＋ｙ）となる。電気伝導度をＣに対してプロットしたときの屈曲点がＣＭＣである（温度25℃）。
【００２４】
得られた界面活性剤組成物を用い、下記に示すモノマー滴下法により乳化重合を行い、得られたポリマーエマルジョンを下記方法で評価した。結果を表１に示す。
【００２５】
(1) 重合安定性（凝集物量）
ポリマーエマルジョンを 200メッシュのステンレス製金網でろ過し、重合後の反応器壁や攪拌羽根等に付着した凝集物も集めて同様にろ過し、水洗後26.6kPa 、105 ℃で２時間乾燥・秤量して、凝集物量を求めた。使用したモノマーの総量に対する凝集物の重量％で、重合安定性を表した。
【００２６】
(2) 機械的安定性
ポリマーエマルジョン50ｇをマロン安定試験機にて10kg、1000r/min の条件で５分間回転させ、生成した凝集物を 200メッシュのステンレス製金網でろ過し、ろ過残渣を水洗後に26.6kPa 、105 ℃で乾燥・秤量して、ポリマーに対する重量％で表示した。
【００２７】
(3) 粘度
Ｂ型粘度計を使用して、ポリマーエマルジョンの粘度を温度25℃、回転数12r/min で測定した。
【００２８】
(4) 平均粒径
コールター社製の動的光散乱法粒径測定装置N-4SD を使用して、ポリマーエマルジョン粒子の平均粒径を測定した。
【００２９】
＜モノマー滴下法＞
セパラブルフラスコにイオン交換水316.25ｇ、界面活性剤組成物8.75ｇ、過硫酸カリウム0.35ｇを仕込み、窒素気流中で30分間攪拌した。
アクリル酸0.9 ｇとアクリル酸ブチル 174.1ｇを混合し、この混合モノマーの8.75ｇを上記フラスコに仕込んだ後、60℃の水浴に入れ昇温した。58℃に達したところで、残りの混合モノマーを２時間かけて滴下した。この間フラスコ内の温度を60±２℃に保った。滴下終了後３時間60℃に保ち熟成した後、室温まで冷却し、ポリマーエマルジョンを得た。
【００３０】
【表１】

【００３１】
実施例12〜18、比較例９〜16
(a) 成分として上記(a-1), (a-2), (a-4), (a-5), (a-7) 及び(a-8) 、(b) 成分として上記(b-1) 〜(b-4) を用い、表２に示す配合割合で本発明及び比較の界面活性剤組成物を製造した。
得られた界面活性剤組成物を用い、下記に示す一括仕込み法により乳化重合を行い、得られたポリマーエマルジョンを上記方法で評価した。結果を表２に示す。
【００３２】
＜一括仕込み法＞
セパラブルフラスコにイオン交換水316.25ｇ、界面活性剤組成物8.75ｇ、過硫酸カリウム0.35ｇを仕込み、窒素気流中で30分間攪拌した。
スチレンモノマー175 ｇを上記フラスコに仕込んだ後、65℃の水浴に入れ昇温した。フラスコ内の温度が約62℃に達したところで、重合反応が開始した。フラスコ内の温度を65±２℃に５時間保ち、重合反応を完結させ、ポリマーエマルジョンを得た。
【００３３】
【表２】

【００３４】
実施例19〜33、比較例17〜32
(a) 成分として上記(a-1) 〜(a-9) 、(b) 成分として上記(b-1) 〜(b-4) を用い、表３に示す配合割合で本発明及び比較の界面活性剤組成物を製造した。
得られた界面活性剤組成物を用い、下記に示すプレエマルジョン法により乳化重合を行い、得られたポリマーエマルジョンを上記方法で評価した。結果を表３に示す。
【００３５】
＜プレエマルジョン法＞
アクリル酸 2.5ｇ、アクリル酸ブチル123.75ｇ、メタクリル酸メチル123.75ｇを混合し、モノマー混合物を調製した。イオン交換水 107.1ｇに界面活性剤組成物 5.0ｇ、過硫酸カリウム0.50ｇを溶解し、これに上記モノマー混合物を混合し、ホモミキサーにて 5000r/min×10分間乳化し、均一なモノマー乳化物を得た。
セパラブルフラスコにイオン交換水 137.9ｇ及び上記モノマー乳化物36.2ｇを仕込み、窒素気流中で30分間攪拌した。次にフラスコを80℃の水浴に入れ昇温した。30分間初期重合させ、残りのモノマー乳化物を２時間かけて滴下した。この間フラスコ内の温度を80±２℃に保った。滴下終了後３時間80℃に保ち熟成した後、室温まで冷却し、ポリマーエマルジョンを得た。
【００３６】
【表３】

【００３７】
【発明の効果】
本発明の界面活性剤組成物を乳化重合の乳化剤として用いると、重合反応中に発生する凝集物の量が少なく（即ち重合安定性が良く）、得られるエマルジョンの機械的安定性も良く、さらに粒径が小さく、粘度の低いエマルジョンが得られる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surfactant composition for emulsion polymerization.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, non-ionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkyl phenyl ethers, alkylbenzene sulfonates, alkyl sulfate esters, polyoxyethylene alkyl ethers during emulsion polymerization of vinyl monomers, etc. Anionic surfactants such as sulfate ester salts, polyoxyethylene alkylphenyl ether sulfate ester salts and higher fatty acid salts are used.
[0003]
Among them, a surfactant having a low critical micelle concentration (hereinafter referred to as CMC) that is effective in a small amount has been used. On the other hand, a surfactant having a high CMC was not suitable as a surfactant for emulsion polymerization.
[0004]
The performance required for these surfactants for emulsion polymerization is that the stability during polymerization and the mechanical stability of the emulsion are good, the particle size of the emulsion is small, the viscosity is low, and environmental problems occur. No surfactant that satisfies all of these performances has been obtained.
[0005]
The subject of this invention is providing the surfactant composition for emulsion polymerization which satisfies all the said performances.
[0006]
[Means for Solving the Problems]
The present invention relates to (a) a compound represented by the general formula (I) having a critical micelle concentration (CMC) in the range of 0.005 to 0.1 mol L ⁻¹ , and (b) represented by the general formula (II) A compound in the range of 1 × 10 ^{−5 to} 0.02 mol L ⁻¹ is an essential component, and the molar ratio of (a) component to (b) component is (a) / (b) = 5/95 to 75/25 A surfactant composition for emulsion polymerization is provided.
[0007]
[Chemical 2]

[0008]
R ² and R ³ are each a monovalent aliphatic hydrocarbon group, A ¹ , A ² , A ³ and A ⁴ are each an alkylene group having 2 to 4 carbon atoms, and p, q and r are each an average addition of an alkylene oxide. A number from 1 to 50 representing the number of moles, s is a number from 0 to 50 representing the average number of moles of alkylene oxide added, M ¹ , M ² and M ³ each represent a monovalent cation, p ¹ A ¹ , q A ² , r A ³ , and s A ⁴ may be the same or different. )
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(A) component of the present invention are represented by the general formula (I), CMC is 0.005～0.1MolL ^-1, preferably compound is in the range of 0.008 to 0.06 molL ^-1, used alone or in combination thereof May be. The component (b) is represented by the general formula (II), CMC is 1 × 10 ^-5 ~0.02 molL ^-1, preferably compound is in the range of 0.001-0.01 molL ^-1, 2 or more types may be alone May be used in combination.
In the present invention, CMC is a value measured by an electric conductivity titration method.
[0010]
In the general formulas (I) and (II), R ¹ is preferably —O— (A ⁴ O) _s −, and particularly preferably A ⁴ is an alkylene group having 3 to ⁴ carbon atoms. R ² is preferably a linear or branched alkyl group having 10 to 24 carbon atoms, particularly 12 to 16 carbon atoms. R ³ is preferably a linear or branched alkyl group having 10 to 24 carbon atoms, particularly 11 to 18 carbon atoms. A ¹ , A ² and A ³ are preferably ethylene groups or propylene groups. When two or more alkylene oxides are added, either random addition or block addition may be used. Moreover, you may combine both addition methods. p, q, r and s are preferably numbers from 3 to 30. M ¹ , M ² and M ³ are preferably alkali metals such as sodium and potassium; ammonium; amines such as alkanolamine.
[0011]
Particularly preferred among the compounds represented by the general formula (I) are compounds represented by the general formula (III).
[0012]
M ¹ SO ₃ -O- (EO) _p- (A ⁵ O) _s- (EO) _q -SO ₃ M ² (III)
(In the formula, M ¹ , M ² , p, q and s represent the above meanings, EO represents an oxyethylene group, and A ⁵ represents a propylene group or a butylene group.)
The compound represented by the general formula (I) includes, for example, polyalkylene glycol, primary amine having a long chain alkyl group or higher fatty acid amide with alkylene oxide such as ethylene oxide and propylene oxide, and then SO ₃ gas, etc. It can be produced by sulfating with a sulfonating agent and neutralizing with NaOH or the like.
[0013]
The compound represented by the general formula (II) is, for example, after adding an alkylene oxide such as ethylene oxide or propylene oxide to an aliphatic monohydric alcohol, and then sulfating with a sulfonating agent such as SO ₃ gas, and adding with NaOH or the like. It can be manufactured by adding.
[0014]
The blending ratio of the component (a) and the component (b) in the composition of the present invention is (a) / (b) = 5/95 to 75/25, preferably 10/90 to 50/50 in molar ratio. is there. When (a) / (b) is less than 5/95, the viscosity of the emulsion becomes high and the mechanical stability is not sufficient. If it exceeds 75/25, the particle size becomes too large, and the polymerization stability and mechanical stability are not sufficient.
[0015]
Specific examples of monomers that can be subjected to emulsion polymerization using the surfactant composition of the present invention include aromatic vinyl monomers such as styrene, α-methylstyrene, and chlorostyrene: methyl acrylate, ethyl acrylate, Acrylic esters such as butyl acrylate: Methacrylic esters such as methyl methacrylate and ethyl methacrylate: Vinyl halides and vinylidene halides such as vinyl chloride, vinyl bromide and vinylidene chloride: Vinyl acetate and vinyl propionate Vinyl esters such as: Nitriles such as acrylonitrile and methacrylonitrile: Conjugated dienes such as butadiene and isoprene. These monomers may be used alone or in combination of two or more.
The surfactant composition of the present invention is preferably used in an amount of 0.1 to 20 parts by weight, particularly 0.5 to 5 parts by weight, based on 100 parts by weight of the monomer.
[0016]
The surfactant composition of the present invention is used in combination with a nonionic surfactant such as polyoxyethylene (ethylene oxide addition mole number 0 to 100) alkyl or alkenyl (alkyl or alkenyl group having 12 to 24 carbon atoms) ether. You can also. Further, a water-soluble protective colloid can be used in combination.
[0017]
There are no particular limitations on the conditions for emulsion polymerization using the surfactant composition of the present invention, and the amount of monomer is preferably 20 to 70% by weight, particularly 40 to 50% by weight, based on the total system. Further, it can be used in any emulsion polymerization method such as a monomer dropping method, a monomer batch charging method, and a pre-emulsion method.
[0018]
【Example】
Examples 1-11, Comparative Examples 1-8
The following (a-1) to (a-9) are used as the component (a), and the following (b-1) to (b-4) are used as the component (b). Agent compositions and comparative surfactant compositions were prepared.
[0019]
[Chemical 3]

[0020]
(b-1): C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0046 mol L ⁻¹
(b-2): C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0012 mol L ⁻¹
(b-3): C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₁₂ SO ₃ Na CMC 0.004 molL ^-1
[0021]
[Formula 4]

[0022]
Here, CMC was measured by the following method.
[0023]
<Measurement method of CMC>
100 mL of distilled water was placed in a beaker and the electric conductivity was measured while stirring (the electric conductivity meter was CM-20S, Toa Denpa Kogyo Co., Ltd., cell CG-511B). 0.2 mL of a surfactant solution adjusted to a predetermined concentration in advance was dropped into a beaker, and the electric conductivity was read each time the solution was dropped. If the surfactant concentration of the titrant is x mol L ⁻¹ and the amount of titrated titrant is y mL, the surfactant concentration C in the solution in the beaker is C = x · y / (100 + y). The inflection point when the electric conductivity is plotted against C is CMC (temperature 25 ° C.).
[0024]
Using the obtained surfactant composition, emulsion polymerization was performed by the monomer dropping method shown below, and the obtained polymer emulsion was evaluated by the following method. The results are shown in Table 1.
[0025]
(1) Polymerization stability (Aggregate amount)
The polymer emulsion is filtered through a 200-mesh stainless steel wire mesh, and the agglomerates adhering to the reactor wall and stirring blade after polymerization are collected and filtered in the same manner. Thus, the amount of aggregate was determined. Polymerization stability was expressed in terms of the weight percent of aggregates relative to the total amount of monomers used.
[0026]
(2) Mechanical stability 50g of polymer emulsion was rotated with a Maron stability tester under conditions of 10kg and 1000r / min for 5 minutes, and the resulting agglomerates were filtered through a 200 mesh stainless steel wire mesh. The sample was dried and weighed at 26.6 kPa and 105 ° C., and expressed in terms of% by weight based on the polymer.
[0027]
(3) Viscosity Using a B-type viscometer, the viscosity of the polymer emulsion was measured at a temperature of 25 ° C. and a rotational speed of 12 r / min.
[0028]
(4) Average particle diameter The average particle diameter of the polymer emulsion particles was measured using a dynamic light scattering particle diameter measuring apparatus N-4SD manufactured by Coulter.
[0029]
<Monomer dropping method>
A separable flask was charged with 316.25 g of ion-exchanged water, 8.75 g of a surfactant composition, and 0.35 g of potassium persulfate, and stirred for 30 minutes in a nitrogen stream.
0.9 g of acrylic acid and 174.1 g of butyl acrylate were mixed, and 8.75 g of this mixed monomer was charged into the flask, and then heated in a 60 ° C. water bath. When the temperature reached 58 ° C., the remaining mixed monomer was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 60 ± 2 ° C. After completion of dropping, the mixture was aged at 60 ° C. for 3 hours and then cooled to room temperature to obtain a polymer emulsion.
[0030]
[Table 1]

[0031]
Examples 12-18, Comparative Examples 9-16
(a) as component (a-1), (a-2), (a-4), (a-5), (a-7) and (a-8), (b) as component (b -1) to (b-4) were used to produce the surfactant compositions of the present invention and comparative compositions at the blending ratios shown in Table 2.
Using the obtained surfactant composition, emulsion polymerization was performed by the batch charging method shown below, and the obtained polymer emulsion was evaluated by the above method. The results are shown in Table 2.
[0032]
<Batch preparation method>
A separable flask was charged with 316.25 g of ion-exchanged water, 8.75 g of a surfactant composition, and 0.35 g of potassium persulfate, and stirred for 30 minutes in a nitrogen stream.
After 175 g of styrene monomer was charged into the flask, it was heated in a 65 ° C. water bath. When the temperature in the flask reached about 62 ° C., the polymerization reaction started. The temperature in the flask was kept at 65 ± 2 ° C. for 5 hours to complete the polymerization reaction to obtain a polymer emulsion.
[0033]
[Table 2]

[0034]
Examples 19-33, Comparative Examples 17-32
(a) Using the above (a-1) to (a-9) as the component and the above (b-1) to (b-4) as the (b) component, A surfactant composition was prepared.
Using the obtained surfactant composition, emulsion polymerization was performed by the pre-emulsion method shown below, and the obtained polymer emulsion was evaluated by the above method. The results are shown in Table 3.
[0035]
<Pre-emulsion method>
A monomer mixture was prepared by mixing 2.5 g of acrylic acid, 123.75 g of butyl acrylate, and 123.75 g of methyl methacrylate. Dissolve 5.0 g of surfactant composition and 0.50 g of potassium persulfate in 107.1 g of ion-exchanged water, mix the above monomer mixture with this, emulsify with a homomixer for 5000 r / min × 10 minutes, and obtain a uniform monomer emulsion Got.
A separable flask was charged with 137.9 g of ion-exchanged water and 36.2 g of the monomer emulsion, and stirred in a nitrogen stream for 30 minutes. The flask was then placed in an 80 ° C. water bath and the temperature was raised. Initial polymerization was performed for 30 minutes, and the remaining monomer emulsion was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 80 ± 2 ° C. After completion of dropping, the mixture was aged at 80 ° C. for 3 hours and then cooled to room temperature to obtain a polymer emulsion.
[0036]
[Table 3]

[0037]
【The invention's effect】
When the surfactant composition of the present invention is used as an emulsifier for emulsion polymerization, the amount of aggregates generated during the polymerization reaction is small (that is, polymerization stability is good), and the resulting emulsion has good mechanical stability. An emulsion having a small particle size and low viscosity is obtained.

Claims (1)

(a) a compound represented by the general formula (I) and having a critical micelle concentration (CMC) in the range of 0.005 to 0.1 mol L ⁻¹ ; and (b) a compound represented by the general formula (II) and having a CMC of 1 × 10 ^{− For} emulsion polymerization in which the compound in the range of ^{5 to} 0.02 mol L ^-1 is an essential component and the molar ratio of component (a) to component (b) is (a) / (b) = 5/95 to 75/25 Surfactant composition.

R ² and R ³ are each a monovalent aliphatic hydrocarbon group, A ¹ , A ² , A ³ and A ⁴ are each an alkylene group having 2 to 4 carbon atoms, and p, q and r are each an average addition of an alkylene oxide. A number from 1 to 50 representing the number of moles, s is a number from 0 to 50 representing the average number of moles of alkylene oxide added, M ¹ , M ² and M ³ each represent a monovalent cation, p ¹ A ¹ , q A ² , r A ³ , and s A ⁴ may be the same or different. )