WO2005107917A1

WO2005107917A1 - Method of purifying object to be treated

Info

Publication number: WO2005107917A1
Application number: PCT/JP2005/008435
Authority: WO
Inventors: Hideki Nakaya; Yuji Imahori; Hirokazu Aoyama
Original assignee: Daikin Industries, Ltd.
Priority date: 2004-05-10
Filing date: 2005-05-09
Publication date: 2005-11-17
Also published as: JPWO2005107917A1; JP4492612B2

Abstract

A purification method by which a fluorochemical surfactant is efficiently removed from an object to be treated which contains the fluorochemical surfactant. The method for the purification of an object to be treated comprises bringing a substance [A] into contact, in the presence of a nonionic surfactant, with the object to be treated which contains a fluorochemical surfactant and water to remove the fluorochemical surfactant, and is characterized in that the substance [A] has a relative permittivity exceeding 4 at the temperature and pressure at which the removal treatment is to be conducted and is liquid at the temperature and pressure, and that the substance [A] and the water separate into two phases at the temperature and pressure.

Description

Specification

Processing object purification method

Technical field

The present invention relates to a method for purifying an object to be treated.

Background art

[0002] Fluorine-containing surfactants have been used as emulsifiers and coagulation stabilizers in emulsion polymerization of fluoropolymers and the like. Recently, there has been active research and development on reducing the content of fluorine-containing surfactants in fluoropolymer products.For example, the reverse osmosis membrane method (e.g., , Patent Document 1.), an ion-exchange membrane method (for example, see Patent Document 2), and the like.

[0003] However, in the method using these membranes, when a fluorine-containing surfactant solution containing a polymer is treated, the membrane is contaminated by clogging, and the membrane needs to be replaced as soon as the treatment is performed. was there. In addition, the supernatant, etc., generated when concentrating the polymer aqueous dispersion after the polymerization or collecting the polymer does not substantially contain the polymer, but removes the fluorine-containing surfactant for wastewater treatment. It is desirable to do.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-58966

Patent Document 2: JP-A-2002-59160

Disclosure of the invention

Problems to be solved by the invention

[0004] In view of the above situation, an object of the present invention is to provide a purification method for efficiently removing a fluorine-containing surfactant from a treatment target containing a fluorine-containing surfactant. Means to solve a problem

[0005] The present invention provides a method for removing a fluorine-containing surfactant by contacting a substance containing a fluorine-containing surfactant and water with a substance [A] in the presence of a non-ionic surfactant. A method for purifying an object to be treated, comprising performing a treatment, wherein the substance [A] has a relative dielectric constant of more than 4 at the temperature and pressure at which the above-mentioned removal treatment is performed, and flows at the above temperature and pressure. A purification method of the object to be treated, wherein the substance [A] and the water are separated into two phases at the above temperature and pressure.

Hereinafter, the present invention will be described in detail.

[0006] The treatment object purification method of the present invention comprises contacting the treatment object with the substance [A] to remove the fluorine-containing surfactant.

[0007] The object to be treated contains a fluorine-containing surfactant.

The fluorine-containing surfactant has a fluorine atom in its molecular structure, has micelle-forming ability, and further has a hydrophilic group and a hydrophobic group.

The above-mentioned fluorine-containing surfactant is preferably made of a fluorine-containing compound having 38 or less carbon atoms per molecule. If the number of carbon atoms per molecule exceeds 38, the surface activity may decrease. The more preferable upper limit of the number of carbon atoms per molecule is 14, the more preferable upper limit is 10, the preferable lower limit is 4, and the more preferable lower limit is 6. The number of carbon atoms per molecule is preferably eight. The fluorine-containing compound may contain a hetero atom. In the present specification, the “hetero atom” is an atom that is neither carbon nor hydrogen, and examples of the atom include oxygen, nitrogen, chlorine, bromine, and iodine. The oxygen atom may form an ether bond.

[0008] The fluorine-containing compound has the following general formula (1)

Y— (CF) — (CH) —A ¹ (1)

2 xl 2 yl

(Wherein, Y represents H or F. xl represents an integer of 4 to 13, yl represents an integer of 0 to 3. A ¹ represents -SOM or -COOM, and M represents H, NH, Li, Na or K.)

3 4

An anionie conjugate having no ether oxygen represented, or the following general formula (2)

F (CF) O (CFXCF O) — CFX— A ¹ (2)

2 x2 2 y2

(Wherein, x2 represents an integer of 1 to 5, y2 represents an integer of 0 to 10. X represents F or CF.

Three

. A ¹ is, as described above. It is preferable that the compound is an Aone conjugate containing ether oxygen represented by the formula (1).

[0009] The above-mentioned A-one ligated product having no ether oxygen includes the following general formula (la)

Y— (CF) — (CH) —A ¹ (la) (In the formula, x3 represents an integer of 6 to 10, y3 represents an integer of 0 to 2. Y and A ¹ are as described above.) A compound represented by the following general formula (Lb)

Y— (CF) —A ¹ (lb)

2 x4

(In the formula, x4 represents an integer of 6 to 10. Y and A ¹ are as described above.)

[0010] The above-mentioned anionie conjugate having ether oxygen is represented by the following general formula (2a)

F (CF) O (CFXCF O) — CFX— COOM (2a)

2 x5 2 y4

(In the formula, x5 represents an integer of 1 to 5, y4 represents an integer of 0 to 3. X and M are as described above.

The compound represented by the following general formula (2b) is more preferable

F (CF) 0 (CF (CF) CF O) — CF (CF) — COOM (2b)

2 x6 3 2 y5 3

(Wherein x6 represents an integer of 1 to 3, y5 represents an integer of 0 to 3. M is as described above.).

M is preferably NH because the fluoropolymer force can be easily removed.

Four

[0011] The object to be treated contains the above-mentioned fluorine-containing surfactant and water.

The object to be treated may also contain other components other than the above-mentioned fluorine-containing surfactant as long as it contains the above-mentioned fluorine-containing surfactant and water! The components are not particularly limited, and include, for example, nonionic surfactants and polymers described below.When the object to be treated is obtained by polymer polymerization, the emulsifier and polymerization stabilizer used in the polymerization are used. It may be a residue polymerization initiator or a chain transfer agent.

[0012] The object to be treated is an object to be brought into contact with the substance [A] in the removal treatment. The processing object is the normal temperature and pressure, such as 20 ° C, 10 ⁵ Pa, or a liquid.

[0013] The object to be treated may contain a fluorine-containing surfactant and water, and may further contain a polymer!

When the object to be treated contains a polymer, it may be an aqueous dispersion or an aqueous non-dispersion comprising a polymer and an aqueous solution of a fluorine-containing surfactant, a wet powder, or the like. Examples of the aqueous dispersion include an aqueous dispersion in which polymer particles are dispersed in an aqueous medium in the presence of the fluorine-containing surfactant.

When the object to be treated is an aqueous dispersion, it contains a polymer, and the removal efficiency of the fluorine-containing surfactant tends to be lower than that of the aqueous solution of the surfactant. This is because the presence of the polymer causes the interaction between the fluorine-containing surfactant and the polymer, or the below-mentioned non-ionic surfactant and the polymer, thereby inhibiting extraction. Conceivable.

The aqueous non-dispersion is, for example, one obtained by precipitating a polymer by subjecting the aqueous dispersion to mechanical shearing by stirring, adding a coagulation aid, or the like, or is composed of a polymer and a surfactant. A liquid material or the like obtained by adding water to a powder so that the state of layer separation between the powder and the water to be added is not collapsed and the water is added to about V ヽ.

The aqueous dispersion and the aqueous non-dispersion are those in which water is 1 part by mass or more based on 100 parts by mass of a non-aqueous substance other than water.

The wet powder is a polymarker powder that is less than 1 part by mass with respect to 100 parts by mass of non-aqueous substances other than hydraulic power.

Examples of the wet powder include a wet powder obtained by adhering the fluorine-containing surfactant to a polymer. The wet powder includes, for example, those obtained by filtering from the aqueous non-dispersion and drying.

When the object to be treated contains a polymer, the polymer is preferably a fluoropolymer.

In the present specification, the above “fluoropolymer” is a polymer having a fluorine atom bonded to a carbon atom. In the present invention, the fluoropolymer is obtained by polymerizing one or more kinds of fluorine-containing monomers, and is obtained by copolymerizing a fluorine-free monomer having no fluorine atom. It may be obtained. The above “fluorine-containing monomer” is a monomer having at least one fluorine atom bonded to a carbon atom.

[0015] As the fluorine-containing monomer, fluorofluorin, preferably fluorofluorin having 2 to 10 carbon atoms; cyclic fluorinated monomer; formula CY = CYOR or CY = ΟΥΟΙ ^ ΟΚ (Υ is Η or F, R is an alkyl group having 1 to 8 carbon atoms in which part or all of a hydrogen atom is substituted with a fluorine atom, and R ¹ is a hydrogen atom A fluorinated alkylbutyl ether represented by the formula (1) is a C1-8 alkylene group partially or wholly substituted with a fluorine atom.

[0016] The fluorofluorin preferably has 2 to 6 carbon atoms. Examples of the fluorinated olefins having 2 to 6 carbon atoms include tetrafluoroethylene [TFE], hexafluoropropylene [HFP], chlorofluoroethylene [CTFE], and fluorinated ethylene [CTFE]. Butyl fluoride, bilidene fluoride [VdF], trifluoroethylene, hexafluoroisobutylene and perfluorobutylethylene. Preferred examples of the cyclic fluorinated monomer include perfluoro-2,2 dimethyl-1,3 dioxol [PDD] and perfluoro-2-methylene-4-methyl-1,3 dioxolan [PMD].

In the fluorinated alkyl vinyl ether, R is preferably one having 1 to 4 carbon atoms, more preferably one in which all of the hydrogen atoms are substituted by fluorine, and R ¹ is preferably Has 2 to 4 carbon atoms, and more preferably has all of the hydrogen atoms replaced by fluorine atoms.

[0017] Examples of the fluorine-free monomer include a hydrocarbon monomer having reactivity with the fluorine-containing monomer. Examples of the hydrocarbon-based monomer include alkenes such as ethylene, propylene, butylene, and isobutylene; ethyl vinyl ether, propyl vinylinoleatenore, butinolevininoleatenole, isobutinolevinineatenoate, Alkyl vinyl ethers such as cyclohexyl vinyl ethers; butyl acetate, butyl propionate, n-butyrate, butyl isobutyrate, valerate, pivalate, caproate, caprylic acid, pudding Acid bur, versatic bur, laurate bur, myristate bur, palmitate bur, stearate bur, benzoate bur, para-t-butyl benzoate bur, cyclohexane carboxylate bur, monochloroacetate bul, adipate bur , Acrylic acid butyl, methacrylic acid butyl , Crotonate, sorbate, cinnamate, pendecylenate, hydroxyacetate, hydroxypropioate, hydroxybutyrate, hydroxyvalerate, hydroxy Buryl esters such as sodium butyrate and hydroxycyclohexanecarboxylate; alkylaryl ethers such as ethylaryl ether, propylaryl ether, butylaryl ether, isobutylaryl ether and cyclohexylaryl ether; Examples thereof include alkylaryl esters such as ethylaryl ester, propylaryl ester, butylaryl ester, isobutylarylester, and cyclohexylaryl ester.

[0018] The fluoropolymer may be greasy, elastomeric, or the like.

When the above fluoropolymer is elastomeric, preferably, the combination of monomers is TFEZPAVE copolymer, VdFZHFP copolymer, VdFZTFEZHFP copolymer, VdFZPAVEZTFE copolymer, VdFZ perfluoro (methyl vinyl ether) [PMVE] Copolymers, VdFZHFPZPMVE copolymers, VdFZTFEZPMVE copolymers, VdFZPMVEZHFPZTFE copolymers, copolymers of TFE with propylene [Pr] and other monomers, and the like.

Composition in the TFEZPAVE copolymer, 40～90Z10～60 (mol ^_0/0) Dearuko and force transducer preferred, the composition of the VdFZTFEZHFP copolymer, 30~85ZO~30 Zl5~40 (mol ^_0/0 ) Is preferable, and the composition in VdFZPAVEZTFE is preferably 10 to 90710 to 400 to 80 (mol%). The composition of the VdFZP MVE copolymer is 65 to 90 10 to 35 (mol%), and the composition of the ¥ (1 to 711 to 7 PMVE copolymer is 65 to 9073 to 25 3 to 25 (mol%). ), the ¥ (composition in 1 ZTFEZPMVE copolymer, 40～80Z3～40Z15～35 (mol ^_0/0) composition in said VdFZPMVEZHFPZTFE copolymer, 40~8θΖ3~25Ζ 3~25 3~40 (mol The composition of the copolymer of TFE, Pr and other monomer is preferably 40 to 70Z30 to 60Z0 to 20 (mol%).

The composition of the copolymer can be analyzed by NMR (nuclear magnetic resonance), IR (infrared spectroscopy), or the like.

[0019] When the fluoropolymer is resinous, it may be a polytetrafluoroethylene polymer [PTF polymer]. In this specification, the PTFE polymer is not only a TFE homopolymer, but also a copolymer of TFE and a fluorine-containing monomer other than TFE and a Z- or fluorine-free monomer, and is a non-melt-processed polymer. It is a concept that includes what is sexual.

The object to be treated contains the above-mentioned fluorine-containing surfactant and water and contains substantially no polymer in terms of the efficiency of the removal treatment (hereinafter referred to as “fluorine-containing surfactant aqueous solution”). Is preferred). Examples of the above-mentioned fluorine-containing surfactant aqueous solution include (1) a supernatant liquid after removing a coagulant when coagulation is performed by adding an acid to an aqueous polymer dispersion, and (2) a fluorine-containing surfactant aqueous solution. When a non-ionic surfactant is added to a fluorine-containing surfactant solution obtained by dissolving a surfactant in water, And a supernatant liquid produced together with the concentrated polymer dispargeon. The supernatant liquid of the above (3) contains the non-ionic surfactant added to the aqueous polymer dispersion, and the non-ionic surfactant is used in order to carry out the method for purifying the treatment object of the present invention. It is efficient that it is not always necessary to newly add.

[0021] In the method for purifying an object to be treated of the present invention, the above-mentioned object to be treated is brought into contact with the substance [A] to carry out the above-described treatment for removing the fluorine-containing surfactant.

The substance [A] is a substance that exceeds the relative permittivity at the temperature and pressure at which the above-mentioned removal treatment is performed and is a fluid at the above temperature and pressure.

The temperature and pressure at which the above-mentioned removal treatment is performed are usually 0 to 150, depending on the type of the substance [A] to be used. C, 0.08-30 MPa, and a preferred lower limit of the above temperature is 5. C, a more preferred lower limit is 20 ° C, a preferred upper limit is 90 ° C, a more preferred upper limit is 50 ° C, and a preferred lower limit of the pressure is 0.1MPa, and a more preferred lower limit is 4MPa. The preferred upper limit is 25 MPa, and the more preferred upper limit is 20 MPa.

[0022] The substance [A] in the present invention is a fluid at the above temperature and pressure. Examples of the fluid include a gas, a liquid, and a supercritical fluid that can extract a fluorine-containing surfactant.

The substance [A] is preferably a supercritical fluid at the temperature and pressure at which the removal treatment is performed.

[0023] The substance [A] in the present invention has a relative dielectric constant at a temperature and a pressure at which the above-mentioned removal treatment is performed. It is more than power.

The substance [A] is brought into contact with the object to be treated under the condition that the relative dielectric constant at the temperature and pressure at which the above-mentioned removal treatment of the compound constituting the substance [A] is performed is within the above range.

The substance [A] is composed of one or more compounds. When the above-mentioned substance [A] is composed of a mixture of two or more kinds of the above-mentioned compounds, in the present specification, the above “relative dielectric constant exceeds 4” means that other than substance [A] Assuming that only the substance (A) that is not present as a mixture with the above components is present in the system, it means that the relative permittivity exceeds 4 at the temperature and pressure at which the above-mentioned removal treatment is performed. .

When the substance (A) is composed of a mixture of two or more compounds, if the relative dielectric constant of the mixture as a whole exceeds 4 at the temperature and pressure at which the removal treatment is performed, Good. Therefore, when the substance (A) is composed of a mixture of two or more compounds, if the relative permittivity of the mixture as a whole exceeds 4 at the temperature and pressure at which the removal treatment is performed, The relative permittivity of at least one compound constituting the substance [A] may exceed 4, and the relative permittivity of another compound constituting the substance [A] may be 4 or less.

The substance [A] and the water contained in the object to be treated are separated into two phases at the temperature and pressure at which the removal treatment is performed. When it becomes one phase, it becomes difficult to remove the fluorine-containing surfactant. When the substance [A] and the water contained in the object to be treated are separated into two phases, (1) Select a substance that will separate into water and two phases at the above temperature and pressure, or (2) It can be formed by adding the above substance [A] in an amount not less than the solubility in water.

As a choice of the above (1), for example, as in the case of methanol and Z or acetone alone, a compound having a relative dielectric constant (e.g., It is important that only the relative dielectric constant is selected, and it is higher than the relative dielectric force at the temperature and pressure at which the above-mentioned removal treatment is performed, but not so high that water and two phases are not separated. Select only the compound (low-permittivity compound) or use a mixture of the high-permittivity compound and the low-permittivity compound so that the relative permittivity at the above temperature and pressure is water and two phases as a whole. It is preferable to select one that is within the range of separation and more than 4. [0025] The compound constituting the substance [A] has a relative dielectric constant exceeding 4 at room temperature and normal pressure, and more than the relative dielectric constant force at the temperature and pressure at which the removal treatment is required. Anything should do.

The relative permittivity of the substance [A] preferably exceeds 4.2, more preferably exceeds 4.21, at the temperature and pressure at which the removal treatment is performed.

The relative permittivity ε is the ratio of the capacitance C of the substance [Α] to the capacitance C in a vacuum [C r 0

ZC], and the relative dielectric constant ε in vacuum is 1.

0 r

[0026] The relative permittivity is a value obtained by measuring a capacitance C when a substance [Α] is filled between the electrodes of a battery and measuring the capacitance C in a vacuum.

0

Generally, the capacitance of the above substance [Α] is measured by a method using a capacitance bridge or a resonance circuit.

[0027] As the compound constituting the substance [Α], an organic compound such as a halogen-containing organic compound is preferable because it is nonflammable and industrially preferable.

As the above-mentioned halogen-containing organic compound, a compound having no chlorine atom is preferable in view of the environment, and a fluorine-containing organic compound is more preferable.

[0028] The organic compound constituting the above substance [Α] is CHFOCI (where i is an integer of 1 to 4).

] k 1 m

And (j + k + m) represents an integer of 0 to 10, and 1 represents an integer of 0 to 10. However, j, k, 1 and m never become 0 at the same time. ) Is preferable.

[0029] When the organic compound constituting the substance [A] has an oxygen atom, the oxygen atom may be an estenol bond [1c (= o) o-C-] or 1c (= o ) —C—, -co—C-, —COOH, —COF, —OH, etc. Among them, some have relative permittivity within the above range, and the extraction efficiency is high. An oxygen atom constituting an ester bond is preferred.

[0030] The organic compound constituting the substance [A] is more preferably a halogenated hydrocarbon, preferably a halogenated hydrocarbon, which is preferably an ester compound. The halogenated hydrocarbon is preferably a fluorinated hydrocarbon.

The fluorinated hydrocarbon is at least one selected from the group consisting of trifluoromethane [R-23], difluoromethane [R-32] and 1,1,1-trifluorofluorene [R-143a]. Fluorine-containing surfactants, which are preferred to be used, have excellent removal efficiency for perfluorooctanoic acid and / or its salt (PFOA), and can establish a nonflammable and safe process. And more preferably R-23.

[0031] In the method of purifying a treatment object of the present invention, the above-mentioned treatment for removing a fluorine-containing surfactant is performed by removing a part or all of the fluorine-containing surfactant contained in the treatment object from the treatment object. This is a process for removing. In the present invention, the method of removing the fluorine-containing surfactant by bringing the substance [A] into contact with the object to be treated is not particularly limited.For example, an aqueous dispersion or an aqueous non-dispersion is shown in FIG. This may be performed using a batch-type apparatus as shown in the schematic diagram, or using a semi-flow-type apparatus used to separate the substance (A) contacted to extract the fluorine-containing surfactant and use it again in the removal treatment. You can go! For example, a wet powder of a resin or an elastomer may be processed in an extruder.

[0032] In the present invention, the contact of the substance [A] with the object to be treated is performed in the presence of a non-one surfactant.

It is considered that the non-ionic surfactant plays a role as an entrainer (extraction aid) in the removal treatment of the fluorine-containing surfactant. For example, when perfluorooctanoic acid ammonium [APFO] is used as the fluorine-containing surfactant and R-23 is used as the substance [A], the relative dielectric constant of R-23 is within the above range. It is difficult to dissolve and extract APFO with R-23 alone even under a certain temperature and pressure. APFO is extracted by coexisting a non-ionic surfactant that is easily soluble in R-23. It becomes possible.

The non-ionic surfactant may be one contained in the object to be treated, or at least dissolved in the substance [A] at the temperature and pressure at which the above-mentioned removal treatment is performed. If so, it may be accompanied by substance [A].

Although the nonionic surfactant is not particularly limited, for example, the following general formula (3): CHO—A ² —H (3)

13 27

(In the formula, A ² represents a polyoxyalkylene chain having 5 to 20 oxyethylene groups and 0 to 6 oxypropylene groups.) In addition to the polyoxyalkylene tridecyl ether-based surfactant represented by — Triton ™ X100, etc. disclosed in 532583 Kilaryl polyethoxy alcohol, alkyl polyethoxy alcohol, etc.

Above all, a polyoxyalkylene tridecyl ether surfactant represented by the above general formula (3) can be suitably used.

A ² in the general formula (3) preferably has 8 to 15 oxyethylene groups and 3 to 3 oxypropylene groups, more preferably 8 to 15 oxyethylene groups and 0 oxypropylene groups. Is more preferred,.

[0034] As the non-ionic surfactant, those described in "Nonionic Surfactants", MJ Schick (editor), Marcel Dekker, Inc., New York 1976 can be used. .

[0035] When the processing object is a wet powder, the nonionic surfactant is preferably added in an amount of 1 to 20% by mass based on the total mass of the processing object. In the case of an aqueous non-dispersion or a fluorine-containing surfactant aqueous solution, it is preferable to add an amount of 3 to 20% by mass of the total mass of the aqueous dispersion, the aqueous non-dispersion or the fluorine-containing surfactant aqueous solution. .

[0036] As described above, the method for purifying a treatment object of the present invention includes removing the fluorine-containing surfactant by bringing the substance [A] into contact with the treatment object in the presence of a nonionic surfactant. Therefore, the fluorine-containing surfactant contained in the object to be treated can be efficiently removed. In the method for purifying a treatment object of the present invention, for example, when the treatment object contains a polymer, the residual amount of the fluorine-containing surfactant contained in the molded article obtained using the polymer This is advantageous in that it can be reduced compared to the conventional case.

The invention's effect

[0037] Since the method for purifying a treatment object of the present invention has the above-described configuration, the fluorine-containing surfactant can be efficiently removed from the treatment object.

BEST MODE FOR CARRYING OUT THE INVENTION

[0038] Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

In the following Examples and Comparative Examples, perfluorooctane was used as the fluorine-containing surfactant. Ammonium acid [APFO] was used, and octylphenoxypolyethoxyethanol (trade name: Triton ™ X100, manufactured by Union Carbide) was used as a non-ionic surfactant.

Example 1

[0039] Fluorine-containing surfactant solution - the [initial APFO concentration 806Ppm, Roh on surfactant Initial concentration 4.5 mass ^_0/0] 5 g, 1 Furuoro one 1 as an extractant, 1-dichloroethane [Ji FH C1

twenty three

; Into the separatory funnel together with [R-141b]], at 20 ° C, under the condition of IMPa (extractant condition:

2

The relative dielectric constant of the liquid and the extractant = 8.2) The two layers were mixed vigorously and allowed to stand for 24 hours.Then, the R-141b layer was sampled, and the concentration of the fluorine-containing surfactant contained was reduced to ¹⁹ F. — NMR (trade name: JNM—EX270, manufactured by JEOL Datum Co., Ltd., trifluoromethane as a reference substance), and the concentration of nonionic surfactant is determined using an ultraviolet-visible spectrophotometer (UV—Vis) (trade name) : 11-3310, manufactured by Hitachi, Ltd.), and was calculated in advance based on the quantitation line prepared from the absorption at the maximum wavelength of 274 nm.

Example 2

[0040] Ethyl acetate was used as the extractant instead of R-141b, and the mixture was stirred at 20 ° C and under the condition of IMPa (extractant state: liquid, relative permittivity of extractant = 7.4). In the same manner as in Example 1, the surfactant was extracted, and the amount of the extracted surfactant was determined.

Example 3

As an object to be treated, 70 g of an aqueous dispersion that has not been coagulated (ie, an aqueous dispersion without coagulation (initial APFO concentration: 1100 ppm, polymer concentration: about 27% by mass, polymer is a fat-like TFE homopolymer)) Aqueous dispersion) to which 7 g of non-ionic surfactant was added, 100 g of trifluoromethane [R-23] was used as an extractant, and at 17.3 ° C and 3. OMPa (extractant) State: The relative permittivity of the liquid and the extractant = 6.8), the two layers were stirred for 1 hour, then left for 24 hours to sample the R-23 layer, and the interface was the same as in Example 1. The activator was extracted and the amount extracted was determined.

Example 4

[0042] Except that the removal treatment was performed under the conditions of 7.9 ° C and 3.2 MPa (state of the extractant: liquid, relative permittivity of the extractant = 6.8), the same procedure as in Example 3 was performed. The surfactant was extracted and the amount extracted was determined. Example 5

The experimental apparatus was performed using a flow-type apparatus as shown in the schematic diagram of FIG. The R-23 gas supplied from the cylinder 1 was cooled by the cooler 2 and then sent to the container by a pump. The vessel was heated with a heater 16 and controlled to 35 ° C. At the outlet side, the pressure was controlled to 15MPa by an automatic back pressure valve 7 (backplate shear regulator). As a result, a supercritical state was realized in the container (relative permittivity of the extractant = 6.6).

A pre-polymerized aqueous dispersion (initial APFO concentration: 1170 ppm, initial concentration of non-ionic surfactant: 10.7% by mass, polymer concentration: approx. 27% by mass, polymer is a fat-like TFE homopolymer ), And stirring was carried out with a stirrer 5 at a stirring speed of 1 60 ppm from the introduction of R-23 to diffuse the substance and heat, and then flow 25 OOg of R-23 at a pump flow rate of 14. OgZ. Was. After passing through the supercritical fluid containing R-23, the pressure is reduced to 0. IMPa by the back pressure valve, the density is reduced to 3.2 g / approximately, and the fluorine-containing surfactant and nonionic interface are reduced in an ice bath 8. The activator was recovered.

The fluorine-containing surfactant was extracted by R-23 in the supercritical state, and as shown in the graph of Fig. 2, it decreased from 1170ppm before removal to 823ppm when 2500g of R-23 was consumed. .

The non-ionic surfactant was also extracted in the same manner, and as shown in the graph of Fig. 3, 10.7% by mass before removal was reduced to 5.05% by mass when 2500 g of R-23 was consumed. Lowered to! The fluorine-containing surfactant concentration and the non-one surfactant concentration were determined as in Example 1.

Example 6

[0044] A fluorine-containing surfactant was extracted in the same manner as in Example 5 except that the object to be treated was changed to an aqueous APFO solution containing a non-ionic surfactant. The concentration and nonionic surfactant concentration were determined.

The fluorine-containing surfactant was extracted by R-23 in the supercritical state, and as shown in the graph of Fig. 4, it decreased from 997 ppm before removal to 75 ppm when 1500 g of R-23 was consumed. . Noon surfactant was also extracted, as shown in the graph of Fig. 5, and 4.5% by mass before removal was reduced to 0.05% by mass when 1500 g of R-23 was consumed. Had dropped to

Example 7

[0045] Difluoromethane [R-32] was used in place of R-23 as the extractant, the temperature was 83 ° C, and the pressure was 6. OMPa (state of the extractant: supercritical fluid, relative permittivity of the extractant = 4). Fluorine-containing surfactant was extracted in the same manner as in Example 6 except that the amount was controlled to 22), and the amount of extraction was determined. The results are shown in Table 1.

The fluorine-containing surfactant was extracted by R-32 in the supercritical state, and was reduced from 806 ppm before the removal treatment to 535 ppm when 120 g of R-32 was consumed. Example 8

Using 10 g of a fluorine-containing surfactant aqueous solution (initial APFO concentration: 876 ppm, initial concentration of non-ionic surfactant: 4.5 mass%), hexane Z ethyl acetate was used instead of R-141b as an extractant. Except that the removal treatment was performed using a mixed medium (volume ratio lZD lOg, 20 ° C, 0. IMPa conditions (extractant condition: liquid, relative dielectric constant of extractant = 4.6)). The fluorine-containing surfactant was extracted and the amount extracted was determined in the same manner as in step 1. The results are shown in Table 1. The fluorine-containing surfactant was extracted and removed by a liquid hexane Z ethyl acetate mixed medium. The power decreased from 876 ppm before treatment to 835 ppm.

Example 9

[0047] In place of R-141b, 10 g of a mixed solvent of hexane and acetone (volume ratio 17:83) was used under the conditions of 20 ° C and 0. IMPa (extractant state: relative permittivity of liquid and extractant) = 5.0), except that the fluorine-containing surfactant was extracted in the same manner as in Example 6 except that the removal treatment was performed. The results are shown in Table 1. The fluorine-containing surfactant was extracted by the liquid hexane Z acetone mixed solvent, and the power was reduced from 876 ppm before the removal treatment to 840 ppm.

Comparative Example 1

[0048] Aqueous dispersion after polymerization (initial APFO concentration 1100ppm, initial concentration of nonionic surfactant 10.7% by mass, polymer concentration about 27% by mass, polymer is lipophilic TFE homopolymer) Same as in Example 5 except that 500 g of R-23 was passed through 70 g under the conditions of 35 ° C and 6.OMPa (extractant condition: supercritical fluid, specific dielectric constant of extractant = 4.0). Then, the extraction amount of the fluorine-containing surfactant was determined. Table 1 shows the results. The fluorine-containing surfactant was not extracted by the supercritical R-23, but was concentrated to 1174ppm when 500g of R-23, which was 100 ppm before the removal treatment, was consumed. This is probably because the water evaporated without APFO being extracted.

Comparative Example 2

[0049] Fluorine-containing surfactant solution (initial APFO concentration 806Ppm, Bruno - one surfactant Initial concentration 4.5 mass ^_0/0) 70 g penta full O b ethane [R- 125] 70. C, under the conditions of 12.4 MPa (extractant state: supercritical fluid, relative dielectric constant of the extractant = 3.7), except that 180 g of the fluorinated surfactant was flowed in the same manner as in Example 6, except that The amount of extraction was determined. The results are shown in Table 1.

The fluorine-containing surfactant was not extracted by R-125 in the supercritical state, and was 806 ppm before the removal treatment, but was concentrated to 1029 ppm when 180 g of R-125 was consumed. Comparative Example 3

[0050] Fluorine-containing surfactant aqueous solution (initial APFO concentration: 806 ppm, initial concentration of non-ionic surfactant: 4.5% by mass) 70 g of R-125 at 70 ° C and 9.36 MPa State: Supercritical fluid, relative dielectric constant of extractant = 3.5 g), and the amount of fluorine-containing surfactant extracted was determined in the same manner as in Example 6, except that 180 g of the extractant were passed. The results are shown in Table 1.

The fluorine-containing surfactant was not extracted by the supercritical R-125, and was concentrated to 866 ppm when 180 g of 806 ppm of the R-125 was consumed before the removal treatment. Comparative Example 4

[0051] polymer aqueous dispersion of the uplink (initial APFO concentration 1100 ppm, Bruno - one surfactant initial concentration of 10.7 mass ^_0/0, the polymer concentration of about 27 weight ^_0/0) in 70 g R- 23 35 ° C (95 ° F) 4. Under the conditions of OMPa (extractant state: gas, relative permittivity of the extractant = 1.4), the amount of fluorine-containing surfactant extracted was the same as in Example 5, except that 500 g of the extractant were passed. I asked. Table 1 shows the results.

The fluorine-containing surfactant was not extracted by the R-23 gas and was concentrated to 1294 ppm when 500 g of the R-23 gas had been consumed before the removal treatment. Comparative Example 5

[0052] Fluorine-containing surfactant solution (initial APFO concentration 806Ppm, Bruno - one surfactant Initial concentration 4.5 mass ^_0/0) 70 g par full O Roe Tan a [R-116] 35 ° C, 6 Extraction amount of the fluorine-containing surfactant in the same manner as in Example 6 except that 750 g was flowed under the conditions of OMPa (extractant state: supercritical fluid, relative permittivity of the extractant = 1.4). I asked. Table 1 shows the results. The fluorine-containing surfactant was not extracted by the supercritical R-116, and was concentrated to 850 ppm when 750 g of the R-116 power was consumed 750 g before the removal treatment. Comparative Example 6

[0053] After cooling the CO gas supplied from the cylinder 1 with the cooler 2, the temperature was increased to 35 ° C and the pressure was increased to 9.0.

2

MPa (extractant state: supercritical fluid, relative dielectric constant of extractant = 1.3), adjust the fluorine-containing surfactant aqueous solution (initial APFO concentration: 1451 ppm, non-ionic surfactant initial concentration) (4.5 mass%) lOOOOg was circulated to 70 g at a flow rate of 12.2 gZ. Supercritical CO after distribution

The pressure of the fluid containing 2 was reduced to 0. IMPa by passing through a pressure relief valve, the density p was reduced to 2.0 gZl, and the fluorine-containing surfactant was recovered in an ice bath. The results are shown in Table 1. Fluorine-containing surfactants are used in supercritical CO

Not extracted by 2 and before the removal process 1

The CO was concentrated to 1463 ppm when 100 g of CO was consumed.

2

Comparative Example 7

[0054] Fluorine-containing surfactant aqueous solution (initial APFO concentration: 963 ppm, initial concentration of non-ionic surfactant: 4.5% by mass) 70 g of CO at 75 ° C and 12. OMPa conditions (state of extractant: Supercritical

2

An attempt was made to recover the fluorine-containing surfactant in the same manner as in Comparative Example 6, except that 2000 g of the fluid and the extractant were distributed at a relative dielectric constant of 1.2). It was not extracted by the CO in the state and consumed 963 ppm before the removal process.

At the time of 22 2, it was concentrated to 1008 ppm.

Comparative Example 8

[0055] Fluorine-containing surfactant solution (initial APFO concentration 876Ppm, Bruno - one surfactant Initial concentration 4.5 mass ^_0/0) with 10g, using hexane 10g to instead of R- 141b as an extractant , 20 ° C, 0. Extraction of surfactant in the same manner as in Example 1 except that removal treatment was performed under the conditions of IMPa (extractant state: liquid, relative dielectric constant of extractant = 1.8) did. Table 1 shows the results. The fluorine-containing surfactant was not extracted by the liquid hexane, and was reduced from 876 ppm before the removal treatment to 882 ppm.

Comparative Example 9

[0056] Using 10 g of acetone instead of hexane as the extractant, the removal treatment was performed at 20 ° C and under the conditions of IMPa (extractant state: liquid, relative dielectric constant of extractant = 20.7). Otherwise, the extraction of the surfactant was attempted in the same manner as in Comparative Example 8, but the extractant was completely dissolved in the aqueous solution of the fluorine-containing surfactant and could not be extracted without separating into two layers.

Comparative Example 10

[0057] Using 10 g of methanol instead of hexane as an extractant, the removal treatment was performed under the conditions of 20 ° C and 0. IMPa (extractant state: liquid, relative dielectric constant of extractant = 32.6). Otherwise, the extraction of the surfactant was attempted in the same manner as in Comparative Example 8, but the extractant was completely dissolved in the aqueous solution of the fluorine-containing surfactant and could not be extracted without separating into two layers.

In the table, the value of the relative dielectric constant was estimated based on the following literature.

1. T. Monyoshi et. Al., Ber. Bunsenges. Pnys. Chem. 97, 589— 596, 1 993

2. Kashiwagi et al., Transactions of the Japan Refrigeration Association, 1, 29-36, 1984

3. Makita et al., Frozen, 52, 543-551, 1977

4. A. P. Abott et al., J. Chem. Eng. Data, 44, 112—115, 1999.

5. Chemical Society of Japan, Basic Handbook of Chemistry II, 4th revised edition, 498-503, 1993

In the table, the concentration of the fluorine-containing surfactant after the purification was also calculated by the extraction capacity with the extractant.

[Table 1]

Fluorine-containing surfactant Treatment target Extractant Nonionic surfactant concentration [ppm] Relative dielectric constant

/ Dish surfactant

(° c) Estimation

Initial density for fe rate Initial type Kinetic star (g) mm Relative dielectric

State Before purification After purification Article

[-] [G] [mass%] Example 1 APF0 aqueous solution 5 20 0.1 R-141b liquid 8.2 5 806 589 5 4.5 Example 2 APF0 aqueous solution 5 20 0.1 I-Ethyl liquid 7.4 5 806 458 5 4.5 Example 3 aqueous Dispersion 70 17.3 3.0 R-23 liquid 6.8 100 1100 1046 3 10.7 Example 4 Aqueous dispersion 70 7.9 3.2 R-23 Liquid 6.8 100 1363 944 3 10.7 Example 5 Aqueous dispersion 70 35 15 R-23 Supercritical fluid 6.6 2500 1170 823 3 10J Example 6 APF0 aqueous solution 70 35 15 R-23 Supercritical fluid 6.6 1500 997 75 3 10.7 Example 7 APF0 aqueous solution 70 83 6.0 R-32 Supercritical fluid 4.22 120 806 535 4 10.7

d lis hexane + acetic acid

Example 8 APF0 aqueous solution 10 20 0.1 ethyl liquid 4.6 10 876 835 5 4.5

(Volume ratio 1: 1)

Hexane + case

Example 9 APF0 aqueous solution 10 20 0.1 ton Liquid 5.0 10 876 840 5 4.5

(17:83 by volume)

Comparative Example 1 Aqueous Dispersion 70 35 6.0 R-23 Supercritical Fluid 4.0 500 1100 1174 3 10.7 Comparative Example 2 APF0 Aqueous Solution 70 70 12.4 R-125 Supercritical Fluid 3.7 180 806 1029 4 4.5 Comparative Example 3 APF0 Aqueous Solution 70 70 9.36 R -125 Supercritical fluid 3.5 180 806 866 4 4.5 Comparative example 4 Aqueous dispersion 70 35 4.0 R- 23 body 1.4 500 1100 1294 3 10J Comparative example 5 APFO aqueous solution 70 35 6.0 R-116 Supercritical fluid 1.4 750 806 850 24.5 Comparative Example 6 APF0 aqueous solution 70 35 9.0 co ₂ Supercritical fluid 1,3 1000 1451 1463 1 4.5 Comparative example A APF0 aqueous solution 70 75 12.0 co ₂ Supercritical fluid 1.2 2000 963 1008 1 4.5 Comparative example 8 APF0 aqueous solution 10 20 0.1 Hexane Liquid 1.8 10 876 882 5 4.5 Comparative example 9 APF0 aqueous solution 10 20 0.1 Acetone liquid 20.7 10 876 1 5 4.5 Comparative example 10 | APFO aqueous solution 10 20 0.1 Methanol liquid 32.6 10 876 ― 5 4.5

[0059] From Table 1, in Examples 1 to 9 using the substance [A] having a large relative dielectric constant at the temperature and pressure at which the removal treatment was performed, the extraction of the fluorine-containing surfactant from the object to be treated proceeded. On the other hand, in Comparative Examples 1 to 8 using the above substances having a small relative dielectric constant, it was evident that the extraction of the fluorine-containing surfactant from the object to be treated did not proceed.

Industrial applicability

[0060] The present invention can be suitably used as a method for efficiently removing a surfactant from various media such as an aqueous dispersion, a polymer wet powder, and a polymer precipitation solution.

Brief Description of Drawings

FIG. 1 is a schematic diagram of an apparatus for experimentally extracting a fluorine-containing surfactant using a supercritical fluid or gas.

[FIG. 2] FIG. 2 is a graph showing the relationship between the amount of CF H consumed and the fluorine-containing boundary in the aqueous dispersion in Example 5.

Three

It is a graph showing surfactant concentration change.

[FIG. 3] FIG. 3 shows nonionic interfaces in an aqueous dispersion with respect to CF H consumption in Example 5.

Three

It is a graph showing activator concentration change.

[FIG. 4] FIG. 4 is a diagram showing a fluorine-containing surfactant aqueous solution with respect to CF H consumption in Example 6.

Three

4 is a graph showing a change in the concentration of a fluorine-containing surfactant in the composition.

[FIG. 5] FIG. 5 is a diagram showing a fluorine-containing surfactant aqueous solution with respect to CF H consumption in Example 6.

Three

5 is a graph showing a change in the concentration of nonionic surfactant in the composition.

Explanation of symbols

[0062] 1 cylinder

2 Cooler

3 Object to be treated (aqueous dispersion, fluorine-containing surfactant aqueous solution, etc.)

4 water bath

5 Stirrer

6 Heater

7 Automatic back pressure valve (back pressure regulator)

8 Ice bath

Claims

The scope of the claims

[1] The removal treatment of the fluorine-containing surfactant by bringing the substance [A] into contact with an object containing the fluorine-containing surfactant and water in the presence of a non-one surfactant. A method for purifying an object to be treated, comprising:

The substance (A) exceeds the relative permittivity at the temperature and pressure at which the removal treatment is performed, and is a fluid at the temperature and pressure.

The substance [A] and the water separate into two phases at the temperature and pressure.

A method for purifying an object to be treated, characterized in that:

[2] The process for purifying an object to be treated according to claim 1, wherein the fluorine-containing surfactant comprises a fluorine-containing compound having 38 or less carbon atoms per molecule.

[3] The fluorine-containing compound has the following general formula (1)

Y— (CF) —

2 xl (CH) — A ¹ (1)

2 yl

(Wherein, Y represents H or F. xl represents an integer of 4 to 13, yl represents an integer of 0 to 3. A ¹ represents -SO M or COOM, and M represents , H, NH, Li, Na or K.)

3 4

Or an ether oxygen-free compound represented by the following formula (2) or F (CF) O (CFXCF O) — CFX—A ¹ (2)

Q x2 2 y2

(In the formula, x2 represents an integer of 1 to 5, y2 represents an integer of 0 to 10. X is F or —CF.

Represents 3. A ¹ represents -SO M or COOM, and M represents H, NH, Li, Na or K

3 4

You. 3. The process for purifying a substance to be treated according to claim 2, which is an anionie conjugate having ether oxygen represented by the formula:

[4] The organic compound constituting the substance [Α] is CHFOC1 (where i represents an integer of 1 to 4,

] k 1 m

j + k + m) represents an integer of 0 to 10, and 1 represents an integer of 0 to 10. However, j, k, 1 and m never become 0 at the same time. 4. The method for purifying an object to be treated according to claim 1, 2 or 3, which is represented by:

[5] The method for purifying an object to be treated according to claim 4, wherein the substance [A] is a supercritical fluid at the temperature and pressure at which the removal treatment is performed.

[6] The organic compounds constituting the substance [A] include trifluoromethane, difluoromethane and 1, 1, 1

6. A process according to claim 5, wherein the at least one member is selected from the group consisting of trifluorene. Object purification method.

[7] The method for purifying an object to be treated according to claim 1, 2, 3, 4, 5, or 6, wherein the object to be treated further contains a polymer.

[8] The method for purifying an object to be treated according to claim 7, wherein the polymer is a fluoropolymer.

[9] The method for purifying an object to be treated according to claim 8, wherein the fluoropolymer is a polytetrafluoroethylene polymer.

[10] The method for purifying a treatment object according to claim 1, 2, 3, 4, 5, or 6, wherein the treatment object does not substantially contain a polymer.