DD239788A1 - METHOD FOR PRODUCING BORDER FLUID ACTIVE PERFLUORO-ACENE SENSORPONATES - Google Patents

Abstract

The invention relates to a process for the preparation of interfacially active perfluoroacylbenzenesulfonates by using aliphatic fluorochemical compounds which are accessible and reaction of perfluoroacyl halides with benzene and subsequent sulfonation. The inventive method is based on the fact that for the first time benzenesulfonates can be produced which carry an aliphatic fluorinated side chain and are stable to hydrolysis. Due to their favorable properties, which include lowering the surface tension of aqueous solutions, they are highly effective additives in fire extinguishing agents and galvanic baths.

Description

As Lewis acid is particularly suitable anhydrous aluminum chloride, which is used in at least a molar amount. The process according to the invention takes place according to the following reaction equation:

RC F- -CO-X ^ CH- - ** RC _- F _9n -CO-CH> η zn 6 ο _e | jw η zn ο

The fluorosurfactants obtainable in this way reduce the surface tension to within the range of 25 to 20 m N / m and are stable in aqueous solution, even when heated to 100 ° C for several days.

embodiments

BeispieM

200g (0,46mol) perfluorooctanoic acid chloride are added dropwise within 90 min with stirring to a suspension of 70g (0.52 mol) of anhydrous aluminum chloride in 400 ml of dry benzene at 5 ⁰ C. The mixture is then stirred at 5 ° C for 1 hour, then at 15 to 20 ⁰ C for 5 hours. The reaction mixture is poured onto 700 ml of ice-water; the organic phase is separated and, after extracting the aqueous phase with diethyl ether, washed together successively with the ether extract with water, aqueous sodium bicarbonate solution and water again until neutral, then dried over potassium carbonate and distilled. There are obtained 127 g (58% yield) of perfluoroheptyl phenyl ketone (boiling point 60 to 62 ⁰ C at 13.33Pa). To 47.4 g (0.1 mol) of this ketone are added dropwise with stirring and cooling in an ice bath 18.5 g 65% oleum (0.15 mol SOs) within 30 min. Thereafter 3 hours, the reaction mixture is in a water bath at 65 to 7O ⁰ C, poured onto ice and neutralized with aqueous Natrontauge. After concentration to dryness of the

Approach in Soxhlet extracted with isopropanol and from the extract the sodium perfluoroctanoylbenzenesulfonate in a Yield of 46.1 g (80% of theory) as white crystals (mp 288 ⁰ C under Zers.) Obtained. The surface tension of aqueous solutions of this salt is:

for a 0.12% solution (2 x 10 ^-3 mol / l) 28,5mN / _m,:;

for each 0.04% solution (7x10 " ⁴ mol / l) 38.0mN / m. /? ""'.

After heating der0,04% solution at 100 ⁰ C for four days was the surface tension still 38.2 mN / m. Example 2

80 g (0.344 mol) of perf luorbuttersäurechlorid are added dropwise within 90 min with stirring to a suspension of 48.7 g (0.365 mol) of anhydrous aluminum chloride in finely powdered form in 200ml of dry benzene at 5 ⁰ C. Thereafter, stirring is continued for three hours at this temperature and then slowly warmed to room temperature. The reaction mixture is poured onto 500 ml of ice-water. The organic phase is separated, the aqueous phase extracted twice with diethyl ether. The combined organic solutions are washed successively with water, aqueous sodium bicarbonate solution and until neutral again with water, dried over magnesium sulfate and distilled. 57,5g (0.21 mol) Perfluorpropylphenylketon (61% yield, boiling point of 174 ⁰ C to 176 ° C) are obtained. 50 g (0.182 mol) of this ketone are dissolved in 80 ml of dry chloroform and treated with stirring and cooling in an ice bath within 30 min with 37 g of 65% oleum (0.3 mol SO ₃ ) and then heated to 50 to 6O ⁰ C for 4 hours. After pouring the reaction mixture onto ice water and separating the organic phase, the aqueous solution is neutralized with Calpiumhydrc cidlösung and concentrated to dryness. By extraction with methanol, 57.5 g (85% of theory) of calcium perfluorobutanoylbenzenesulfonate are obtained

The surface tension of a 0.5% solution of this compound (0.7 × 10 ^-3 mol / l) is 25.8 mN / m.

Example 3

150 g (0.411 mol) of oH-perfluoroheptanoic acid chloride are added dropwise to a suspension of 58 g (0.43 mol) of anhydrous aluminum chloride in 300 ml of dry benzene at 5 ° C. within 30 minutes, then at 5 ° C. for 1 hour and at 20 ° C. for 4 hours After the organic phase has been separated off and the aqueous phase is extracted with diethyl ether, the combined organic solutions are washed again with water, aqueous sodium bicarbonate solution and, until neutral, with water, dried over magnesium sulphate and distilled (0.26 mol; 64% yield) of ωH-perfluorohexylphenyl ketone are obtained, to which 100 g (0.246 mol) of this ketone are added dropwise with stirring and cooling in an ice bath 49 g of 65% oleum (0.4 mol SO ₃ ) within 45 minutes Heated with stirring to 5O ⁰ C and poured the reaction mixture on ice After separating the water-insoluble fractions is the wäßri ge solution neutralized with triethanolamine solution in water and concentrated to dryness. Extraction with isopropanol gives 119 g (0.287 mol) of triethanolammonium ωΗ-perfluoroheptanoylbenzenesulfonate (76% yield).

The surface tension of a 1% solution of this salt in water (1.57 χ 10 ~ ² mol / l) is 20.4mN / m.

Claims (2)

Invention claim: 1. A process for the preparation of perfluoroacylbenzenesulfonate surfactants of the general formula. RC _n F _2n -CO-C ₆ H ₄ -SO ₃ M,
in the R = F or H,
η = Ibis 9 and M = Na, K, V2Ca or NR ¹ R ² R ³ R ⁴ , where R ¹ , R ² , R ³ and R ⁴ independently of one another may be hydrogen, CH ₃ , C ₂ H ₅ or C ₂ H ₄ OH, in that perfluoroacyl halides are reacted with benzene at temperatures of from 0 to 20 ^° C. in the presence of a Lewis acid for from 0 to 5 to 6 hours, the resulting perfluoroacylbenzene with a sulfonating agent, such as oleum or sulfur trioxide, at temperatures of 0 to 60 ° C in the presence or absence of a solvent such as chloroform or dichloromethane, and the reaction product is neutralized and extracted after concentration to dryness with alcohol. 2. The method according to item 1, characterized in that is used as the Lewis acid anhydrous aluminum chloride. Field of application of the invention The invention relates to a process for the preparation of perfluoroacylbenzenesulfonate surfactants which can be used as highly effective additives in fire extinguishing or electroplating baths. Characteristic of the known technical solutions It is known that surfactants whose molecules carry a fluorinated aliphatic carbon chain have more advantageous properties over similar nonfluorinated aliphatic carbon chain materials. Due to their special properties such as high thermal and chemical stability and significant reduction in surface tension, such substances are valuable, often indispensable, additives. GB-PS 1130822 discloses perfluoroalkeneoxybenzenesulfonates. However, these tend due to their C-C double bond contained in the molecule for the elimination of hydrogen fluoride, as soon as they come in contact with traces of moisture. Therefore, they are unsuitable for use in aqueous media. They then quickly lead to acidification of the medium and thus possibly also to corrosion of the materials used. Object of the invention . , The object of the invention is to produce surface-active substances which on the one hand have a fluorinated moiety, but on the other hand are chemically more stable than the previously known perfluoroalkeneoxybenzenesulfonates. Explanation of the essence of the invention The object of the invention is achieved by a process for the preparation of perfluoroacylbenzenesulfonate surfactants of the general formula RC _n F _2n -CO-C ₆ H ₄ -SO ₃ M,
in the R = F or H
η = Ibis 9 and M = Na, K, V2Ca or NR ¹ R ² R ³ R ⁴ , wherein R ¹ , R ² , R ³ and R ^{4 may} independently be hydrogen, CH ₃ , C ₂ H 5 O or C ₂ H ₄ OH, mean by reacting according to the invention perfluoroacyl halides with benzene at temperatures of 0 to 20 ° C in the presence of a Lewis acid for 0.5 to 6 hours, the resulting perfluoroacylbenzene with a sulfonating agent, such as oleum or sulfur trioxide, at temperatures from 0 to 60 ⁰ C in the presence or absence of a solvent such as chloroform or dichloromethane, and the reaction product is neutralized and extracted after concentration to dryness with alcohol.