JPH0370714B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyfluoroalkyl phosphates, and more specifically, to a method for producing polyfluoroalkyl phosphates using polyfluoroalcohol and pyrophosphoryl halide. The polyfluoroalkyl phosphates obtained by the present invention can be prepared by the general formula (However, Rf in the formula is a polyfluoroalkyl group having 5 to 14 carbon atoms, R is a divalent alkylene group having 1 to 4 carbon atoms, R ¹ , R ² , and R ³ are each a hydrogen atom,
_{−CH2CH2OH , −CH2CH2CH2OH} , _{−CH ( CH3} )
CH ₂ OH, or

[Formula], where m is an average value and represents a number satisfying 1≦m≦2. ) can be produced.
Such fluorine-containing phosphate esters are useful as water-soluble surfactants or oil repellents for treating textile fibers, paper, and other similar materials, and
The manufacturing method is described in Publication No. 4770, Japanese Patent Publication No. 56-29875, etc. When used as an oil repellent, if m in the general formula (1) is close to 3, oil repellency will be impaired, so it is desirable that no triester is formed. However, in the conventionally known methods for producing fluorine-containing phosphate esters, they are obtained as a mixture of monoesters, diesters, or triesters, and therefore measures are currently taken to suppress the production of triesters. be. However, through research conducted by the present inventors, a simple method that does not require such control means, that is, an innovative method in which hardly any triester is produced from the beginning, has been discovered. That is, it was found that by using the polyfluoroalkyl phosphates obtained according to the present invention, the alkanolamine salts thereof are less likely to become triesters. The present invention relates to a method for producing such polyfluoroalkyl phosphates, which have the general formula
2 to 4 moles of polyfluoroalcohol represented by RfROH (in the formula, Rf is a polyfluoroalkyl group having 5 to 14 carbon atoms and R is a divalent alkylene group having 1 to 4 carbon atoms) and pyrofluoroalcohol. The present invention relates to a method for producing polyfluoroalkyl phosphates, which comprises reacting with 1 mole of phosphoryl halide and then hydrolyzing. In the present invention, as the polyfluoroalcohol with the general formula RfROH, a wide range of conventionally known and well-known polyfluoroalcohols are employed, and Rf has 5 carbon atoms.
~14, especially 6 to 12 perfluoroalkyl groups, R is a divalent alkylene group having 1 to 4 carbon atoms, especially 1 to 2 carbon atoms. Rf and R may be linear or branched. Furthermore, a mixture of polyfluoroalcohols having Rf with different carbon numbers may of course be employed in the present invention. Also, general formula

As the pyrophosphoryl halide represented by the formula (X; halogen atom such as Cl, Br, etc.), pyrophosphoryl chloride in which all Xs are Cl is preferred because it is industrially easily available. In the reaction between polyfluoroalcohol and pyrophosphoryl halide (hereinafter referred to as the first stage reaction), the molar ratio of the former/latter is 2 to 4/1, preferably 3 to 4/1.
It can be implemented at 3.8/1. Reaction temperature is 60-120
C, preferably 80 to 100 C, and the reaction time is suitably 15 mm to 10 hr, preferably 1 hr to 5 hr. The polyfluoroalkylphosphohalide thus obtained has the general formula (However, Rf, R, and m are the same as above. s represents a number satisfying 0<s≦1 as an average value, and X represents a halogen atom.) Although the number m increases by increasing the reaction molar ratio of polyfluoroalcohol to pyrophosphoryl halide, m is rarely greater than 2. Therefore, the main formation of undesirable compounds with m close to 3 can be automatically controlled from the beginning. Next, the polyfluoroalkylphosphohalogen compound is hydrolyzed to form a polyfluoroalkylphosphate.

[Formula] is formed (hereinafter referred to as the second stage reaction). General formula ()
When m is close to 2, the appropriate number of moles of water to react with 1 mole of polyfluoroalkylphosphohalide is 2.6 to 5.0 moles, preferably 3 to 4 moles. On the other hand, when m is close to 1, the above value may be 5.2 to 10 mol, preferably 6 to 8 mol. That is, as m becomes larger, the number of reacting moles of water may be smaller. The reaction temperature is
70-100℃, preferably 85-95℃, reaction time 0.5
~4 hours, preferably 1 to 2 hours is appropriate. In the first and second stage reactions, HCl
Hydrogen halides such as are produced as by-products. In the present invention, it is desirable to sufficiently separate and remove such by-product hydrogen halide before the next third stage reaction. If hydrogen halide remains, it will form a salt with ethanolamines in the third stage reaction, which will be detrimental to the smooth and advantageous reaction between polyfluoroalkyl phosphate and ethanolamines, and will also affect the oil repellency and viscosity of the final product. will have a negative impact on Such by-product hydrogen halide can be driven out using an inert gas such as nitrogen gas. For example, by carrying out the first stage reaction and the second stage reaction while introducing an insoluble gas, by-product hydrogen halide can be sufficiently expelled from the reaction system. In the present invention, separation and removal of by-product hydrogen halide may be carried out by using an acid acceptor such as a tertiary amine containing no functional group as described in Japanese Patent Publication No. 48-4770. Preferably, the expulsion method using an inert gas as described above is employed. That is, it is necessary to separate an acid acceptor such as a tertiary amine from the reaction system, and the remaining acid acceptor or hydrogen halide-acid axis acceptor salt can be removed in the third stage reaction in the same manner as described above. This will lead to serious disadvantages. A suitable example of the use of the polyfluoroalkyl phosphates obtained by the present invention is the production of alkanolamine salts of the compounds as described above. In this reaction, the molar ratio of alkanolamines/polyfluoroalkyl phosphate is 1.0 to 5.0/1, preferably 1.2 to 3.0/1, and water is preferably 200% by weight or more based on the polyfluoroalkyl phosphate. is 400~600% by weight
It is carried out using a moderate amount. If the amount of water used is too small, the viscosity of the reaction system becomes excessive, which impedes a uniform, smooth and advantageous reaction, and the desired product cannot be obtained as an advantageous aqueous solution.
Furthermore, if the amount of water used is too small, the oil repellency of the final product will also be insufficient. The reaction temperature range is from room temperature to about 100°C. In order to stabilize the alkanolamine salt produced in a suitable dispersion state in water, it is important that the temperature is at least 80-100°C. It takes
The holding time at a temperature of 80° C. or higher is about 3 to 12 hours, preferably about 5 to 8 hours. Therefore,
Normally, the second half of the reaction is maintained at 80°C or higher. Of course, the entire reaction can be carried out at 80°C or higher, and the first half can also be carried out at a lower temperature. For example, room temperature to 100℃, preferably 30℃
A method may be employed in which the reaction is carried out at ~60°C for 1 to 30 hours, preferably 1 to 2 hours, and then the reaction is carried out at 80 to 100°C for 3 to 12 hours, preferably about 5 to 8 hours. In addition, by treating the final product with a homogenizer or ultrasound, a stable dispersion can be obtained.
The aforementioned holding operation can be omitted. Examples of the alkanolamines used in such a reaction include ethanolamine, propanolamine, isopropanolamine, and t-butanolamine. These alkanolamines include mono, di, and
There are tri-substituted compounds, and these may be used alone or in a mixture of two or more. In this way, the alkanolamine salt of polyfluoroalkyl phosphate represented by the general formula () is obtained as an aqueous solution. The aqueous solution of the alkanolamine salt is preferably formed with a viscosity of about 10 to 250 centipoise. Such specific fluorine-containing phosphate esters are particularly useful for oil repellent purposes. For example, the repellency of various solid materials such as textile fabrics, textile yarns, leather, paper, plastic sheets, wood, ceramics, clay, etc. and articles made therefrom, such as clothing, wallpaper, paper bags, cardboard boxes, porous ceramics, etc. Used for oil treatment. Especially margarine, donuts,
It is effectively used for oil-repellent treatment of wrapping paper for oil-based foods such as tyokolate and medical food, or wrapping paper containers. The specific alkanolamine salt obtained as an aqueous solution is preferably obtained at a concentration of usually 5 to 30% by weight, particularly 15 to 20% by weight, but it is of course possible to dilute this appropriately when used for oil repellent treatment. It is possible. Usually, the specific fluorine-containing phosphate ester concentration
It is preferable to use an aqueous solution diluted to about 0.3 to 1.0% by weight as an oil repellent. When used for the purpose of oil repellency on paper, not only the internal addition method, that is, the method of adding during paper making, but also methods such as padding, spraying, brushing, impregnation coating, etc. can be adopted. Next, examples of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanations. In addition, in the following examples, the proportions are weight proportions unless otherwise specified. Example 1 38.5 g of pyrophosphoryl chloride was placed in a 300 ml flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen inlet tube, and the temperature was raised to 85° C. while flowing dry nitrogen gas. 200 g of C ₈ F ₁₇ CH ₂ CH ₂ OH was added dropwise from the dropping funnel over 60 minutes. Stirring was continued for an additional hour at 85°C, and then 5g of water was added dropwise over 15 minutes. The reaction was continued until the generation of hydrogen chloride stopped. This intermediate 80
22g of diethanolamine and water heated to 85℃
It was dropped into 395 g of aqueous solution over 15 minutes. The patient developed a fever and the temperature rose to 90°C. Stirring was continued for 10 hours, and the reaction was stopped when the viscosity decreased to 30 centipoise. Results of analyzing the reaction product using infrared absorption spectrum It was confirmed that The proportion of tris ester in this reaction product was 3.0 wt%. Example 2 50 g of the intermediate synthesized in Example 1 was neutralized with an aqueous solution of monoethanolamine to obtain 20% (C ₈ F ₁₇ CH ₂ CH ₂ O) _1.5 P(O)(OH・NH ₂
280 g of an aqueous solution containing _1.5 CH ₂ CH ₂ OH) was obtained. Example 3 50 g of the intermediate synthesized in Example 1 was neutralized with an aqueous triethanolamine solution to obtain 20% (C ₈ F ₁₇ CH ₂ CH ₂ O) _1.5 P(O) [OH・N(C
320 g of an aqueous solution containing H ₂ CH ₂ OH) ₃ ] _1.5 was obtained. Example 4 100g of C _o F _2o+1 CH ₂ CH ₂ OH (n=6, 8, 10,
(C _o F _2o+1 CH ₂ CH ₂ O) _1.7 P(O)(OH) _1.3 using 14.70 g of pyrophosphoryl chloride containing 20%, 45%, 22%, and 13% of 12, respectively). synthesize,
Neutralize with diethanolamine aqueous solution and stir at 90℃ for 10 hours to form (C _o F _2o+1 CH ₂ CH ₂ O) _1.7 P(O)[OH・NH(C
An aqueous solution of H ₂ CH ₂ OH) ₂ ] _1.3 was obtained. The proportion of triester in the reactant was 3.3 wt%. Comparative Example 1 Phosphorus oxychloride was added to a 300 ml flask equipped with a stirrer, dropping funnel, thermometer and nitrogen inlet tube.
Add 44.5g and heat to 85 while flowing dry nitrogen gas.
The temperature was raised to ℃. 200 g of C ₈ F ₁₇ CH ₂ CH ₂ OH was added dropwise from the dropping funnel over 60 minutes. Stirring was continued for an additional hour at 85°C. The reaction was continued until the evolution of hydrogen chloride stopped. 80 g of this intermediate was dropped over 15 minutes into an aqueous solution of 22 g of diethanolamine and 395 g of water heated to 85°C. The temperature of the fever rose to 90°C.
Stirring was continued for 10 hours, and the reaction was stopped when the viscosity decreased to 30 centipoise. Results of analyzing the reaction product using infrared absorption spectrum It was confirmed that The proportion of tris ester in this reaction product was 15.4 wt%. Comparative Example 2 100g of C _o F _2o+1 CH ₂ CH ₂ OH (n=6, 8, 10,
12 (containing 20%, 45%, 22%, 13%, respectively) and 17 g of phosphorus oxychloride and 3.5 g of water (C _o F _2o+1
CH ₂ CH ₂ O) _1.7 P(O)(OH) _1.3 was synthesized, neutralized with an aqueous solution of diethanolamine, and stirred at 90°C for 10 hours to form (C _o F _2o+1 CH ₂ CH ₂ O) _1.7 P(O) [OH・NH(C
An aqueous solution of H ₂ CH ₂ OH) ₂ ] _1.3 was obtained. The proportion of triester in the reactant was 16.0 wt%. Reference Example The oil repellency of the phosphoric ester aqueous solution synthesized by the method of the present invention and the phosphoric ester aqueous solution synthesized by the methods of Comparative Examples 1 and 2 was compared using the following method. While stirring 200 g of a 1% aqueous dispersion of unbleached kraft pulp, 1 g of a 1% aqueous solution of polyethyleneimine was added in portions. Stirring was continued for 5 minutes, and then 10 g of a 0.1% aqueous solution of phosphoric acid ester was added dropwise and mixed. After stirring for an additional 5 minutes, paper was made using a standard hand-scraper according to JIS-P8209. Wet paper was pressed between sheets of paper to thoroughly absorb water, and then dried in a drum dryer (100°C x 60 seconds) to prepare oil-resistant paper. Comparison of oil repellency was performed as follows. Place one drop of the test oil shown in Table 1 on the treated paper and observe the state of oil penetration after 15 seconds. The highest number that does not penetrate is considered the oil repellency of the treated paper. The higher the number, the better the oil repellency. Table 2 shows the oil repellency of the oil-repellent papers treated with the phosphoric acid esters synthesized by the methods of Examples 1-4 and Comparative Examples 1-2.

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Claims (1)

[Claims] 1 General formula RfROH (however, Rf in the formula has 5 carbon atoms
~14 polyfluoroalkyl groups, R is 1 carbon number
Polyfluoroalkyl phosphates characterized by reacting 2 to 4 moles of polyfluoroalcohol represented by ~4 divalent alkylene groups with 1 mole of pyrophosphoryl halide and then hydrolyzing the mixture. manufacturing method.