JP3355233B2 - Fluorinated anionic surfactant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to two sulfone groups useful as surface modifiers for fibers, metals, resins, etc., emulsifiers for emulsion polymerization of fluoropolymers, antistatic agents, emulsifiers, dispersants, etc. A novel fluorinated anionic surfactant having the formula:

[0002]

2. Description of the Related Art Conventionally, fluorine-containing anionic surfactants have been used as emulsifiers for emulsion polymerization of fluorine-based polymers, ink stain inhibitors, antistatic agents and the like. Among them, fluorinated anionic surfactants using hexafluoropropene as a raw material are disclosed in Japanese Patent Application Laid-Open No. 57-164.
No. 199, the fluorine-containing anionic surfactant is:
Hexafluoropropene dimer or trimer can be obtained by reacting with phenol using tertiary amine as a reaction accelerator, sulfonating and then neutralizing.
However, since it has only one sulfone group in the molecule, its solubility in water is poor and its use in aqueous systems is limited, and emulsifiers, dispersants, and emulsifiers for emulsion polymerization of fluorine-based polymers are used. There was a limit to its use.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the conventional fluorine-containing anionic surfactants, maintains a high surface activity utilizing fluorine, has good solubility in water, It can be used as an emulsifier, dispersant, surface modifier, antistatic agent, etc., as well as special emulsifiers for emulsion polymerization of low-polymerized fluoropolymers, crosslinkers, and solubilizers of fluorochemicals in water Provided is a fluorine-containing anionic surfactant which is also used for applications.

[0004]

The present invention provides a compound represented by the following general formula (1):

[0005]

Embedded image (Wherein, X represents an alkali metal). X in the general formula (1)
Represents an alkali metal, such as lithium, sodium, potassium, and cesium, and is preferably sodium or potassium.

The production method of the general formula (1) includes the general formula (2):

[0007]

Embedded image (Where X is as defined above) by dissolving or dispersing the alkali metal salt of hydroxybenzenesulfonic acid in a non-aqueous polar solvent, and gradually dropping a trimer of hexafluoropropene to cause a reaction. can get.

[0008] Here, as the non-aqueous polar solvent, an amide-based solvent having relatively large dissolving power and large polarity is preferable.
N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylimidazoline, N-methylpyrrolidone and the like.

Specific examples of the hexafluoropropene trimer include the following formulas (3) and (4):

[0010]

Embedded image

[0011]

Embedded image Is shown, but a single compound may be used or a mixture may be used.

In the present invention, the compound of the formula (4) reacts with the alkali metal salt of hydroxybenzenesulfonic acid to obtain the desired product of the general formula (1). Since the propene trimer gives an equilibrium mixture with the formula (4) under basic conditions, the reaction may use the formula (3). For example, Equation (3) / Equation (4) =
The 1/1 equilibrium mixture readily isomerizes with each other in dimethylformamide in the presence of a base such as triethylamine to give the equilibrium mixture formula (3) / formula (4) = 2/1 (organic synthetic chemistry). 39, No. 1, P51 (198
1)) In the case of the present invention, hydroxybensulfonic acid 2 alkali metal salt acts as a base.

The reaction molar ratio of the dibasic salt of hydroxybenzenesulfonic acid and the trimer of hexafluoropropene is preferably from 1: 1 to 5: 1, particularly preferably from 2: 1 to 3: 1. Theoretically, hydroxyalkane di-alkali metal salt requires twice equivalent, and in the case of equivalent, the general formula (5):

[0014]

Embedded image Is produced in large quantities. In the case of a large excess of 5 times equivalent or more,
The reaction proceeds but is not economically favorable.

[0015] The reaction temperature is preferably from 40 ° C to 100 ° C, particularly preferably from 60 ° C to 80 ° C. Below 40 ° C,
Since the solubility is low and the reaction rate is low, a large amount of the alkali metal salt of hydroxybenzenesulfonic acid remains in a large amount.
A temperature of 0 ° C. or higher is not preferable because the solvent deteriorates.

The hexafluoropropylene trimer is added gradually since a large amount of by-product perfluorononenyloxybenzenesulfonate (general formula (5)) is formed when added at once. Is preferred. For example, in the production on a 1 liter scale, the addition is preferably performed for 1 hour or more.

[0017]

The present invention will be described below with reference to examples. Example 1 130 g (0.6 mol) of p-hydroxybenzenesulfonic acid disodium salt was placed in a 1-liter four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a dropping funnel.
Disperse in 600 ml of dimethylformamide and stir 8
After warming to 0 ° C., hexafluoropropene trimer (mixture of formula (3) / formula (4) = 38.5 / 61.5)
135 g (0.3 mol) was added dropwise in about 4 hours. After stirring was continued for 1 hour, the reaction was stopped, NaF was filtered off, and 1200 ml of toluene was added to the filtrate to precipitate a solid. After the solid was separated by filtration, the solid was washed three times with 600 ml of hot isopropyl alcohol to obtain 157 g (yield: 65.2%) of compound (1a).

[0018]

Embedded image Table 1 shows the physical properties of the compound (1a).

[0019]

[Table 1]

Example 2 The surface tension of compound (1a) was measured by the Wilhelmy method. The measurement temperature was set at 30 ° C. Table 2 shows the surface tension at each concentration.

Comparative Example 1 A 5-liter 4-neck flask equipped with a cooling pipe, a thermometer, and a stirrer was charged with 3 kg of N, N-dimethylformamide and 1.65 kg of hexafluoropropene trimer (3.67 mol).
l) and 687 g (3.15) of anhydrous p-hydroxybenzenesulfonic acid disodium salt at 60 ° C. while stirring.
mol) was added in 10 equivalents and added in 10 portions every 30 minutes. Thereafter, stirring was continued for 2 hours, and the stirring was stopped.
After heating, the by-produced NaF was separated by filtration while maintaining the temperature, and the filtrate was cooled and recrystallized to 5 ° C. The precipitated crystals are separated by filtration, dried, and sodium perfluorononenyloxybenzenesulfonate Formula (5a):

[0022]

Embedded image 1.68 kg (85.3% by weight). At the end of the reaction, the reaction yield of sodium perfluorononenyloxybenzenesulfonate in the reaction mixture was 94.8%. In this reaction, the formula (1a) was expressed as 1 by-product as a by-product. .2% by weight.

[0023]

The fluorinated anionic surfactant according to the present invention has two hydrophilic sulfone groups together with a perfluoro group having excellent properties such as water and oil repellency and antifouling properties, and therefore has a high affinity for water. Has good solubility and is useful as an emulsifier for emulsion polymerization of a fluorine-based polymer, a crosslinking agent, and a solubilizer of a fluorine-based reagent in water.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C09K 3/00 C09K 3/00 R Z 3/16 108 3/16 108D (72) Inventor Hiroyuki Obama Kosai-cho, Koga-gun, Shiga Prefecture Ikemachi 1-1, Neos Co., Ltd. (56) References JP-A-57-164199 (JP, A) JP-A-50-117727 (JP, A) JP-A-6-263714 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) C07C 303 / 32,309 / 42 C08F 2/26 B01F 17/12

Claims (2)

(57) [Claims] 1. General formula (1): (Wherein, X represents an alkali metal.) A fluorine-containing anionic surfactant represented by the formula: 2. General formula (2): (Wherein X represents an alkali metal) Dissolve or disperse the hydroxybenzenesulfonic acid di-alkali salt in a non-aqueous polar solvent, and then add hexafluoropropene trimer to obtain a general formula ( 1) The method for producing a fluorine-containing anionic surfactant. Embedded image