JPH0430942B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to novel perfluorohexylbenzyl sulfonic acid and salts thereof. The new compounds are particularly useful as fluorine-containing surfactants. Prior Art Fluorine-containing surfactants include those with a linear fluorocarbon acid obtained by an electrolytic fluorination method, and those with a linear or side-chain fluorocarbon acid obtained by a perfluoroolefin telomerization method. Some are known that are made from a fluorocarbon having a chain, and others are obtained by oligomerization of tetrafluoroethylene or hexafluoropropene. All of these are aliphatic fluorine-containing surfactants. On the other hand, aromatic fluorosurfactants made from perfluoroalkenyl aryl ethers obtained by reacting oligomers of tetrafluoroethylene and hexafluoropropene with phenols have been developed by ICI and the applicant of the present application, and are commercially available. It has come into widespread practical use. However, conventional aromatic fluorine-containing surfactants still have a double bond in their fluorocarbon acid and an ether bond in the hydrophobic group that contributes to a hydrophilic group. In some cases, a fluorine-containing surfactant with completely saturated fluorocarbon chains is required. However, perfluoroalkyl aromatics, in which a perfluoroalkyl group is directly substituted on an aromatic ring, have unique reactivity, as is well known, and the perfluoroalkyl group decomposes in the presence of a strong acidic reagent. However, it is difficult to introduce a hydrophilic group, such as a carboxylic acid group or a sulfone group, into the aromatic ring, which is essential for surfactants, using conventional synthetic methods [Chemical Society of Japan, Chemistry Review No. 27 (1979), "New Foundations"] "Elementary Chemistry" pp. 183-208]. Therefore, perfluoroalkyl aromatic surfactants have not yet been commercialized. However, when a perfluoroalkyl group is bonded to an aromatic ring, such as a benzene ring, through a methylene group as shown in formula [], the perfluoroalkyl group can be bonded to an aromatic ring, such as a benzene ring, using a synthetic method similar to that used in the industrialization of conventional surfactants. It has been found that hydrophilic groups can be introduced into aromatic rings in high yield without decomposition. In addition, the obtained fluorinated surfactant has properties similar to existing fluorinated surfactants, such as low surface tension (18.9 mN/m (5.9 × 10 ^-3 mol /). Object of the Invention The present invention relates to the provision of a novel compound having a saturated perfluoroalkyl group and its application to a surfactant. Constitution of the Invention The present invention relates to the formula: [In the formula, M is hydrogen, n-valent metal, ammonia,
amine, alkanolamine, n represents 1 to 3] and salts thereof. The novel compound of the present invention has the formula: It can be obtained by sulfonating the compound shown. Compound [] is hexafluoropropene,
For example, a hexafluoropropene dimer (perfluorohexene) obtained by anionic polymerization in the presence of a base or fluoride ion is reacted with a metal fluoride (e.g., CsF) to form a perfluorocarbanion. It can be obtained by reacting this with benzyl halide. Representative reaction examples are shown below. [In the formula, X represents halogen] [HNMAKAROV, et.al., Journal of
Fluorine Chemistry, Vol. 10, 157-158 (1977)] Sulfonation may be carried out using concentrated sulfuric acid, fuming sulfuric acid, or sulfuric anhydride. The obtained sulfonated product may be neutralized using a suitable alkali to form a salt. It can also be obtained by using chlorosulfonic acid instead of concentrated sulfuric acid or fuming sulfuric acid and directly neutralizing the obtained sulfonic acid chloride with an alkali. In addition, the starting material hexafluoropropene 2
The polymer can be easily synthesized by the methods described in Japanese Patent Nos. 1128707 and 1128733. In the present invention, X may be hydrogen, but
When used as a surfactant, it is preferable to neutralize with a suitable alkali, specifically alkali metals such as Na and K, alkaline earth metals such as Ca and Mg,
Examples include other metals such as Al, Zn, and Zr. 3
Monovalent alkali metals are preferred except for special uses such as water and oil repellents. X may further be a nitrogen-containing base such as ammonia, amines, alkanolamines, and the like. Effects of the Invention The compounds obtained in the present invention are useful as surfactants, and in particular, their water-soluble salts exhibit very low surface tension even at low concentrations. In addition, water-insoluble salts are useful as mold release agents and water and oil repellents. Example 1 (1) Compound [](1-phenyl-2,2-bis(trifluoromethyl)-3,3,4,4,5,
Production of 5,5-heptafluoropentane: 10 g (0.033 mol) of hexafluoropropene dimer and 6 g (0.04 mol) of CsF were mixed with 20 g of diglyme.
After stirring at 50°C for 30 minutes, a solution of 6.8gr (0.04ml) of benzylglomide in 20ml of diglyme was gradually added dropwise. After completion of the dropwise addition, the mixture was stirred at 50°C for 12 hours, left to cool, and then poured into water. The oil layer was collected, washed several times with water, and extracted with CH ₂ Cl ₂ . After CH ₂ Cl ₂ was distilled off, 12.8 g of pale yellow liquid was obtained. The physical property values are shown in Table-1.

[Table] (2) Production of perfluorohexylbenzyl sulfonic acid: Compound obtained in (1) [ ] 10.0 g (0.024 mol)
30°C under moisture-proof conditions while keeping at room temperature (20°C).
% fuming sulfuric acid (0.03 mol as SO ₃ ) was slowly added dropwise with stirring. After reacting for 5 hours, the mixture was allowed to stand and the reaction product in the upper layer was separated and collected (crude yield: 90%). The obtained sulfonated product was a brown viscous liquid. (3) Neutralization of sulfonic acid: 0.6g of sodium hydroxide (1st grade reagent) and 30ml of water
The above crude reaction product 5 was dissolved in water and cooled with ice water.
g was gradually added to neutralize the pH to 6.0±0.5. Add 200 ml of isopropyl alcohol to this, remove the precipitated white precipitate (Na ₂ SO ₅ ), distill off water and isopropyl alcohol, add 200 ml of isopropyl alcohol again, and remove the precipitated white precipitate (Na ₂ SO _{5 )} . ) left again. The isopropyl alcohol was distilled off and the residue was dried at 60°C. 10.80 g (87.9% yield) of a pale yellow solid product was obtained.
The analytical values of the obtained product are shown in Table 2. Table 3 shows the surface tension, foaming properties, and penetrating power of the product.

【table】

【table】

[Table] (2) Ross-Miles foam test method
(3) Canvas-disk method

Claims (1)

[Claims] 1 Formula: [In the formula, M is hydrogen, n-valent metal, ammonia,
amine, alkanolamine, n represents 1 to 3] and salts thereof.