JP4108985B2 - Fluorine-containing sulfate surfactant - Google Patents

Description

［式中、Ｘ_１およびＸ_２は水素原子または−ＳＯ_３Ｍ（式中、Ｍは水素原子またはアルカリ金属原子を示す）を示し（但し、Ｘ_１およびＸ_２の少なくとも一方は−ＳＯ_３Ｍを示す）、Ｒｆはパーフルオロヘキセニル基またはパーフルオロノネニル基を示す］
で表される含フッ素硫酸エステル系界面活性剤に関する。
【０００５】
【発明の実施の形態】
本発明による含フッ素硫酸エステル系界面活性剤の製造法は特に限定的ではないが、好適な製造法を以下に説明する。
先ず、ヘキサフルオロプロペンのダイマーまたはトリマーを、非水極性溶媒中において、塩基性触媒の存在下でソルケタールと反応させることによって、一般式（II）：
【化３】

（式中、Ｒｆは前記と同意義である）
で表されるエーテル化合物を調製する。
【０００６】
上記反応で使用する非水極性溶媒としては、テトラヒドロフラン、ジメチルホルムアミド、ジオキサン、ジエチレングリコールジメチルエーテル、ジエチルエーテルおよびアセトニトリル等が例示されるが、特にアセトニトリルが好ましい。
【０００７】
また、上記反応で使用する塩基性触媒としては、苛性ソーダ、苛性カリ、炭酸ソーダ、炭酸カリおよびトリアルキルアミン等が例示されるが、特にトリエチルアミンおよび炭酸カリが好ましい。
【０００８】
さらに、上記反応におけるヘキサフルオロプロペンのダイマーまたはトリマーとソルケタールとの反応モル比は、通常、２：１〜１：１、好ましくは、１.２：１〜１.０５：１である。
なお、反応温度および反応時間は、通常、それぞれ２５〜４０℃および６〜２４時間である。
【０００９】
次いで、一般式（II）で表されるエーテル化合物を鉱酸、例えば、塩酸、硫酸、リン酸または硝酸（好ましくは、塩酸）の水溶液中で加水分解させることによって、一般式（III）：
【化４】

（Ｒｆは前記と同意義である）
で表されるアルコール化合物を調製する。
なお、加水分解温度は、通常、５０〜１００℃である。
【００１０】
上記の加水分解によって得られるアルコール化合物（III）を発煙硫酸または無水硫酸等を用いる硫酸エステル化処理に付し、さらに所望により該硫酸エステル化物を適宜のアルカリ金属含有アルカリで中和することによって、一般式（Ｉ）で表される含フッ素硫酸エステル系界面活性剤が得られる。
【００１１】
なお、上記の硫酸エステル化処理温度は、通常、−５〜２０℃であり、また、該硫酸エステル化物のアルカリ中和温度は、通常、５〜２５℃である。
【００１２】
本発明による含フッ素硫酸エステル系界面活性剤（Ｉ）の上記製造法において用いるヘキサフルオロプロペンのダイマーおよびトリマーの代表的な化合物としては、次式（IV）および（Ｖ）で表される化合物が例示される。
【化５】

【化６】

【００１３】
このようなヘキサフルオロプロペンオリゴマーは、ソルケタール等のヒドロキシル化合物のヒドロキシル基と反応してエーテル結合を形成する（特開昭５２−４１１８２号公報参照）。
【００１４】
以下、本発明を実施例によって説明する。
実施例１
攪拌機、温度計、冷却管および滴下漏斗を備えた四つ口フラスコ（１０００ｍｌ）内にソルケタール１０２．９６ｇ（０．７８モル）、トリエチルアミン８６．６６ｇ（０．８５８モル）およびアセトニトリル３５０ｍｌを入れ、該フラスコ内を３０℃に保ちながら、該混合物中へヘキサフルオロプロペントリマー（Ｖ）３８６．１ｇ（０．８５８モル）を約３０分間かけて攪拌下で徐々に滴下した。滴下終了後、３０℃で攪拌をさらに８時間続行した。
反応混合物を分液漏斗に移した後、水４００ｍｌを用いる洗浄処理に３回付し、次いで０．１Ｎ塩酸２００ｍｌを用いる洗浄処理に２回付すことによって、粗製エーテル化合物（IIａ）を４２３.７ｇ得た。
【化７】

【００１５】
攪拌機と溶媒留去装置を備えた四つ口フラスコ（５００ｍｌ）内へ上記の粗製エーテル化合物の全量を移し、０．５Ｎ塩酸５０ｍｌとメタノール１２０ｍｌを加えた後、加水分解によって生成するアセトンを留去させながら、加熱攪拌を４時間続行した。
次いで、メタノール１５ｍｌと水１５ｍｌを添加した後、加熱攪拌をさらに３時間続行した。反応混合物を分液漏斗に移した後、水２００ｍｌを用いる洗浄処理に１回付し、次いで１％炭酸水素ナトリウム水溶液２００ｍｌを用いる洗浄処理に１回付し、さらに水１５０ｍｌを用いる洗浄処理に２回付した後、残存する水をロータリーエバポレーターで留去することにより、アルコール化合物（IIIａ）を３７８ｇ得た。
【化８】

【００１６】
上部に塩化カルシウム管を具有する等圧側管付き滴下漏斗および攪拌機を備えた四つ口フラスコ（５００ｍｌ）内にアルコール化合物（IIIａ）４６．８ｇ（０．０８９７モル）とジエチルエーテル１００ｍｌを入れ、この混合物中へ、氷水浴（０〜５℃）で冷却しながら、３０％発煙硫酸５２．６ｇ（ＳＯ_３換算で０．１９７モル）を約３０分間かけて攪拌下で徐々に滴下した。滴下終了後、氷水浴を取り外し、得られた混合物を室温で１時間攪拌して硫酸エステル化をおこなった。
【００１７】
三角フラスコ（１リットル）内に水酸化ナトリウム３８ｇ（０．９７モル）と水３００ｍｌを加えて調製した水溶液中へ、氷水浴（０〜５℃）で冷却しながら、上記硫酸エステル化の反応混合物を約３０分間かけて攪拌下で徐々に滴下した。滴下終了後、得られた反応混合物に食塩を飽和量添加することによって、目的化合物（Ｉａ）を析出させた。
【化９】

【００１８】
該析出物を吸引濾過によって濾取し、これを飽和食塩水２００ｍｌで２回洗浄した後、再び吸引濾過処理に付し、濾取物を減圧乾燥機内で乾燥させた。該乾燥固体をソックスレー抽出器内でのアセトン連続抽出処理に付し、抽出物をロータリーエバポレーターで乾固させることによって、精製化合物（Ｉａ）を３７ｇ得た。
化合物（Ｉａ）の物性を表１に示す。
【００１９】
【表１】

【００２０】
【発明の効果】
本発明による含フッ素硫酸エステル系界面活性剤は、１分子中に含フッ素基と共に、スルホン基を２個まで有することができるので、フッ素に特有の高界面活性を損なうことなく、水に対して改良された溶解性を示すので、乳化剤、分散剤、表面改質剤、帯電防止剤、撥油剤および付着防止剤等として使用できるだけでなく、低重合度のフッ素系高分子の乳化重合用乳化剤、架橋剤および水に対するフッ素系試薬の可溶化剤等としても有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel fluorine-containing sulfate ester surfactant useful as a surface modifier such as fibers, metals and resins, an emulsifier for emulsion polymerization of a fluorine-based polymer, an antistatic agent and a dispersant.
[0002]
[Prior art]
Fluorine-containing anionic surfactants have been conventionally used as emulsifiers for emulsion polymerization of fluoropolymers, ink stain inhibitors, antistatic agents, and the like. As this type of surfactant, for example, those using hexafluoropropene as a raw material are known (see JP-A-57-164199). This surfactant is prepared by sulfonating the product obtained by reacting a dimer or trimer of hexasafluoropropene with phenol in the presence of a tertiary amine and then neutralizing the sulfonated product. However, in the case of this type of fluorine-containing anionic surfactant, the solubility in water is insufficient due to the presence of only one sulfone group in the molecule. There is a problem that there is a limit to the use of such emulsifiers, dispersants, and emulsifiers for emulsion polymerization of fluoropolymers.
[0003]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems of this type of fluorine-containing anionic surfactant, thereby improving the solubility in water without impairing the high surface activity unique to fluorine. It can be used as an emulsifier, a dispersant, a surface modifier, an antistatic agent, an oil repellant, an anti-adhesive agent, etc. The present invention has been made to provide a novel fluorine-containing sulfate ester surfactant that can be used as a solubilizer for a fluorine reagent.
[0004]
[Means for Solving the Problems]
That is, the present invention relates to the general formula (I):
[Chemical formula 2]

[Wherein, X ₁ and X ₂ represent a hydrogen atom or —SO ₃ M (wherein M represents a hydrogen atom or an alkali metal atom) (provided that at least one of X ₁ and X ₂ represents —SO ₃ M Rf represents a perfluorohexenyl group or a perfluorononenyl group]
It is related with the fluorine-containing sulfate type | system | group surfactant represented by these.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Although the manufacturing method of the fluorine-containing sulfate type | system | group surfactant based on this invention is not specifically limited, A suitable manufacturing method is demonstrated below.
First, a hexafluoropropene dimer or trimer is reacted with a solketal in the presence of a basic catalyst in a non-aqueous polar solvent to give a general formula (II):
[Chemical 3]

(Wherein Rf is as defined above)
An ether compound represented by the formula is prepared.
[0006]
Examples of the non-aqueous solvent used in the above reaction include tetrahydrofuran, dimethylformamide, dioxane, diethylene glycol dimethyl ether, diethyl ether and acetonitrile. Acetonitrile is particularly preferable.
[0007]
Examples of the basic catalyst used in the above reaction include caustic soda, caustic potash, sodium carbonate, potassium carbonate and trialkylamine, and triethylamine and potassium carbonate are particularly preferable.
[0008]
Furthermore, the reaction molar ratio of the hexafluoropropene dimer or trimer to the solketal in the above reaction is usually 2: 1 to 1: 1, preferably 1.2: 1 to 1.05: 1.
In addition, reaction temperature and reaction time are 25-40 degreeC and 6-24 hours normally, respectively.
[0009]
Subsequently, the ether compound represented by the general formula (II) is hydrolyzed in an aqueous solution of a mineral acid such as hydrochloric acid, sulfuric acid, phosphoric acid or nitric acid (preferably hydrochloric acid), thereby obtaining the general formula (III):
[Formula 4]

(Rf is as defined above)
The alcohol compound represented by these is prepared.
In addition, a hydrolysis temperature is 50-100 degreeC normally.
[0010]
By subjecting the alcohol compound (III) obtained by the hydrolysis to a sulfuric esterification treatment using fuming sulfuric acid or anhydrous sulfuric acid, and further neutralizing the sulfated ester with an appropriate alkali metal-containing alkali as desired. A fluorine-containing sulfate ester surfactant represented by the general formula (I) is obtained.
[0011]
In addition, said sulfuric esterification processing temperature is -5-20 degreeC normally, and the alkali neutralization temperature of this sulfated ester is 5-25 degreeC normally.
[0012]
Representative compounds of hexafluoropropene dimers and trimers used in the above production method of the fluorine-containing sulfate surfactant (I) according to the present invention include compounds represented by the following formulas (IV) and (V): Illustrated.
[Chemical formula 5]

[Chemical 6]

[0013]
Such a hexafluoropropene oligomer reacts with a hydroxyl group of a hydroxyl compound such as solketal to form an ether bond (see JP-A-52-41182).
[0014]
Hereinafter, the present invention will be described by way of examples.
Example 1
In a four-necked flask (1000 ml) equipped with a stirrer, thermometer, condenser and dropping funnel, 102.96 g (0.78 mol) of solketal, 86.66 g (0.858 mol) of triethylamine and 350 ml of acetonitrile were placed. While maintaining the inside of the flask at 30 ° C., 386.1 g (0.858 mol) of hexafluoropropene trimer (V) was gradually added dropwise to the mixture with stirring over about 30 minutes. After completion of the dropwise addition, stirring was further continued at 30 ° C. for 8 hours.
After the reaction mixture was transferred to a separatory funnel, it was subjected to a washing treatment with 400 ml of water three times and then twice with a washing treatment with 200 ml of 0.1N hydrochloric acid to obtain 423.7 g of a crude ether compound (IIa). Obtained.
[Chemical 7]

[0015]
Transfer the entire amount of the above crude ether compound into a four-necked flask (500 ml) equipped with a stirrer and a solvent distillation apparatus, add 50 ml of 0.5N hydrochloric acid and 120 ml of methanol, and then distill off the acetone produced by hydrolysis. While stirring, heating and stirring were continued for 4 hours.
Subsequently, 15 ml of methanol and 15 ml of water were added, and the stirring with heating was further continued for 3 hours. After the reaction mixture is transferred to a separatory funnel, it is subjected to a washing treatment using 200 ml of water once, then to a washing treatment using 200 ml of a 1% aqueous sodium hydrogen carbonate solution, and further to a washing treatment using 150 ml of water. After circulation, 378 g of alcohol compound (IIIa) was obtained by distilling off the remaining water using a rotary evaporator.
[Chemical 8]

[0016]
46.8 g (0.0897 mol) of alcohol compound (IIIa) and 100 ml of diethyl ether were placed in a four-necked flask (500 ml) equipped with a dropping funnel with an isobaric side tube having a calcium chloride tube at the top and a stirrer. While cooling with an ice water bath (0 to 5 ° C.), 52.6 g of 30% fuming sulfuric acid (0.197 mol in terms of SO ₃ ) was gradually added dropwise to the mixture with stirring over about 30 minutes. After completion of the dropwise addition, the ice-water bath was removed, and the resulting mixture was stirred at room temperature for 1 hour to effect sulfate esterification.
[0017]
The above reaction mixture for sulfate esterification was cooled in an aqueous solution prepared by adding 38 g (0.97 mol) of sodium hydroxide and 300 ml of water in an Erlenmeyer flask (1 liter) while cooling with an ice water bath (0 to 5 ° C.). Was gradually added dropwise with stirring over about 30 minutes. After completion of the dropwise addition, the target compound (Ia) was precipitated by adding a saturated amount of sodium chloride to the resulting reaction mixture.
[Chemical 9]

[0018]
The precipitate was collected by suction filtration, washed twice with 200 ml of saturated brine, then subjected to suction filtration again, and the filtered product was dried in a vacuum dryer. The dried solid was subjected to continuous acetone extraction treatment in a Soxhlet extractor, and the extract was dried to dryness on a rotary evaporator to obtain 37 g of purified compound (Ia).
Table 1 shows the physical properties of Compound (Ia).
[0019]
[Table 1]

[0020]
【The invention's effect】
Since the fluorine-containing sulfate ester surfactant according to the present invention can have up to two sulfone groups together with fluorine-containing groups in one molecule, it does not impair the high surface activity unique to fluorine, Since it exhibits improved solubility, it can be used not only as an emulsifier, dispersant, surface modifier, antistatic agent, oil repellent and anti-adhesive agent, but also as an emulsifier for emulsion polymerization of fluoropolymers having a low degree of polymerization, It is also useful as a solubilizer for a fluorine-based reagent with respect to a crosslinking agent and water.

Claims (1)

Formula (I):

[Wherein, X ₁ and X ₂ represent a hydrogen atom or —SO ₃ M (wherein M represents a hydrogen atom or an alkali metal atom) (provided that at least one of X ₁ and X ₂ represents —SO ₃ M Rf represents a perfluorohexenyl group or a perfluorononenyl group]
A fluorine-containing sulfate ester surfactant represented by: