JP2007002072A - Nonionic surfactant aqueous composition production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a reusable nonionic surfactant aqueous composition at a low cost by reducing the content of a fluorine-containing surfactant or the like.
SOLUTION: (1) A step of adding a specific compound to the water to be treated using water to be treated having an organic acid compound, a nonionic surfactant, an aqueous medium, and a fluorine-containing polymer content of 5% by mass or less. (2) A method comprising a step of performing a contact treatment comprising contact with activated carbon and / or contact with a cation exchange resin on the primary treatment aqueous composition obtained in step (1), wherein the specific compound is It is represented by an inorganic ionic compound composed of a cation that forms a water-insoluble salt with an organic acid compound, or a basic organic compound that forms a water-insoluble salt or a water-insoluble coordination product with the organic acid compound. A nonionic surfactant aqueous composition production method.
[Selection figure] None

Description

The present invention relates to a method for producing a nonionic surfactant aqueous composition.

A fluorine-containing polymer aqueous dispersion is generally obtained by polymerization in an aqueous medium in the presence of a fluorine-containing organic acid compound such as perfluorooctanoic acid [PFOA] or perfluorooctylsulfonic acid [PFOS]. The aqueous dispersion obtained by polymerization is usually concentrated and used because of its low fluoropolymer concentration.

Examples of the concentration method of the aqueous dispersion of the fluorine-containing polymer include, for example, a phase separation concentration method (for example, refer to Patent Document 1), an ultrafiltration method (for example, refer to Patent Document 2), and an electric concentration method (for example, Patent Document). 3, etc.) are known. Such concentration is generally performed by adding a nonionic surfactant for stabilizing the dispersion. The residue obtained by collecting the fluorinated polymer concentrated aqueous dispersion may contain a small amount of fluorinated polymer, but it is an aqueous composition comprising an aqueous medium, and contains a fluorinated organic acid compound and a nonionic surfactant. Despite containing, it has been discarded as waste liquid.

Since nonionic surfactants are generally expensive, concentration of an aqueous dispersion of a fluorine-containing polymer has a problem of increasing costs. In order to solve this problem, it is desirable to recover and reuse the nonionic surfactant from the waste liquid that has been conventionally discarded. However, when reusing the nonionic surfactant, it is necessary to remove the fluorine-containing organic acid compound from the waste liquid.

As a method for removing and recovering the fluorine-containing emulsifier from the waste liquid as the fluorine-containing organic acid compound, an aqueous permeate separated from the fluorine-containing polymer concentrated aqueous dispersion by passing the aqueous dispersion of the fluoropolymer through an ultrafiltration semipermeable membrane A method of capturing and recovering a fluorine-containing emulsifier by passing (waste liquid) through a basic anion exchange resin has been proposed (for example, see Patent Document 2). However, the use of an anion exchange resin requires a complicated operation, and there is a problem that the cost is increased.
US Patent No. 3037953 Japanese Patent Laid-Open No. 55-120630 (Claim 4) British Patent No. 642025

The object of the present invention is to reduce the content of organic acid compounds such as fluorine-containing surfactants and to produce a reusable nonionic surfactant aqueous composition at a low cost in view of the above-mentioned situation. Is in the provision of.

The present invention produces an aqueous nonionic surfactant composition using an aqueous composition to be treated which comprises an organic acid compound, a nonionic surfactant and an aqueous medium, and the content of the fluoropolymer is 5% by mass or less. A nonionic surfactant aqueous composition production method, wherein the nonionic surfactant aqueous composition production method comprises:
(1) adding a specific compound to the aqueous composition to be treated, and
(2) A method comprising a step of performing a contact treatment comprising contact with activated carbon and / or contact with a cation exchange resin on the primary treatment aqueous composition obtained by the step (1), wherein the specific compound is: An inorganic ionic compound comprising a cation that forms a water-insoluble salt with the organic acid compound, or a basic organic compound that forms a water-insoluble salt or a water-insoluble coordination product with the organic acid compound, The following general formula (I)
R ¹ -Z (I)
(In the formula, R ¹ represents a linear or branched hydrocarbon group that may have a hetero atom and H may be substituted with F, F or H, and Z represents —COOM ¹ , — It represents a group derived from SO ₃ M ¹ or phosphoric acid, and M ¹ represents H, NH ₄ , Na or K.) A method for producing a nonionic surfactant aqueous composition.
The present invention is described in detail below.

The method for producing an aqueous nonionic surfactant composition of the present invention uses an aqueous composition to be treated which comprises an organic acid compound, a nonionic surfactant, and an aqueous medium and has a fluorine-containing polymer content of 5% by mass or less. Thus, a nonionic surfactant aqueous composition is produced.

The said to-be-processed aqueous composition consists of an organic acid compound, a nonionic surfactant, and an aqueous medium.
The organic acid compound generally has the following general formula (I)
R ¹ -Z (I)
(In the formula, R ¹ represents a linear or branched hydrocarbon group that may have a hetero atom and H may be substituted with F, F or H, and Z represents —COOM ¹ , — SO ₃ M ¹ or a phosphate-derived group, and M ¹ represents H, NH ₄ , Na or K).

In the general formula (I), when R ¹ is a hydrocarbon group, examples of the hydrocarbon group include H (CF ₂ ) _n — or F (CF ₂ ) _n — (n is Represents an integer of 1 to 12.).
The above-mentioned n has a preferred lower limit of 4 and a preferred upper limit of 8.
In the present specification, the “heteroatom” is at least one selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. When the hydrocarbon group as R ¹ has a hetero atom, the hetero atom is preferably an oxygen atom and / or a nitrogen atom, and more preferably an oxygen atom. The oxygen atom that the hydrocarbon group as R ¹ may have is preferably an oxygen atom constituting an ether bond and / or an ester bond. The nitrogen atom that the hydrocarbon group as R ¹ may have is preferably a nitrogen atom constituting an amino group or a substituted amino group.
The hydrocarbon group as R ¹ in the general formula (I) preferably has no hetero atom, and preferably has a hydrogen atom substituted with fluorine.
The hydrocarbon group as R ¹ preferably has 4 to 20 carbon atoms, and more preferably 5 to 12 carbon atoms.
R ¹ is preferably an alkyl group in which H is substituted with F, and more preferably a perfluoroalkyl group.

In the general formula (I), Z represents —COOM ¹ , —SO ₃ M ^1, or a phosphate-derived group.
In the present specification, the “phosphoric acid-derived group” is a group that can be referred to as a phosphoric acid residue derived from phosphoric acid [H ₃ PO ₄ ], and includes —PO ₃ H ₂ M ² , —PO ₃ HM ² ₂ , It is at least one selected from the group consisting of —PO ₃ M ² ₃ , —OPO (OM ¹ ) ₂ , —O (PO ₂ M ¹ ) _1/2 and —O (PO) _1/3 .
The M ¹ represents H, NH ₄ , Na or K, and the M ² represents NH ₄ , Na or K.
In the phosphoric acid-derived group, when there are two or more M ¹ or M ² in one molecule, the two or more M ¹ or the two or more M ² may be different from each other. , Usually the same thing.
In the general formula (I), when Z is a phosphoric acid-derived group, the following formula [R ^1- (O) _p- ] _x PO (OM ¹ ) _3-x
(P represents an integer of 0 or 1, x represents an integer of ^{1 to} 3. R ¹ and M ¹ are as defined above. (3-x) pieces of M ¹ are mutually identical. May be different or different.).
Z is preferably —COOM ¹ (M ¹ is the same as described above), more preferably —COONa.

As the organic acid compound represented by the general formula (I), those having an average molecular weight of 1000 or less are preferable, and those having an average molecular weight of 500 or less are more preferable in terms of easy removal.
The organic acid compound preferably has 4 to 12 carbon atoms.
As long as the said organic acid compound is represented by the said general formula (I), only 1 type may be contained in an aqueous liquid, and 2 or more types may be contained.
The organic acid compound is preferably a fluorine-containing surfactant, and more preferably perfluorooctanoic acid or a salt thereof. In the present specification, “perfluorooctanoic acid or a salt thereof” may be abbreviated as “PFOA” generically.

In the aqueous composition to be treated, the organic acid compound is preferably 0.001 to 2% by mass of the aqueous medium in total when performing the removal treatment.
In terms of removal efficiency, the organic acid compound is more preferably 0.05% by mass or more, and more preferably 0.1% by mass or less of the aqueous medium.
In this specification, the amount of the organic acid compound is a value determined from ¹⁹ F-NMR (measuring instrument AC300P, manufactured by Bruker Biospin).

As the nonionic surfactant, known nonionic surfactants can be used, for example, ether type nonionic surfactants such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, ethylene, and the like. Ester-type nonionic surfactants such as polyoxyethylene derivatives such as oxide / propylene oxide block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, and polyoxyethylene fatty acid esters And amine nonionic emulsifiers such as polyoxyethylene alkylamine and alkylalkanolamide.
Moreover, the nonionic surfactant which does not have an alkylphenol in a structure can be used preferably.

It is preferable that the said nonionic surfactant is 0.1-30 mass% of the to-be-processed aqueous composition in this invention, a more preferable minimum is 0.5 mass%, and a more preferable upper limit is 25 mass%.
In the present specification, the content (N) of the nonionic surfactant is about 1 g (Xg) of a sample taken in an aluminum cup having a diameter of 5 cm and heated at 100 ° C. for 1 hour, The obtained heating residue (Yg) was calculated from the formula: N = [(Y−Z) / X] × 100 (%) from the heating residue (Zg) heated at 300 ° C. for 1 hour. .

The aqueous medium in the present invention is not particularly limited as long as it is a liquid containing water, and in addition to water, for example, a fluorine-free organic solvent such as alcohol, ether, ketone, paraffin wax, and / or a fluorine-containing organic solvent. It may be included.

In the present invention, the aqueous composition to be treated is one having a fluorine-containing polymer content of 5% by mass or less in addition to the organic acid compound, nonionic surfactant and aqueous medium, preferably It is 1 mass% or less, More preferably, it is 0.1 mass% or less.
As the above-mentioned aqueous composition to be treated, when it is a residual waste liquid obtained by separating a fluoropolymer concentrated aqueous dispersion from a fluoropolymer aqueous dispersion obtained by polymerization, a composition containing no fluoropolymer is preferable. If it is in the range, it may be, for example, 0.01% by mass or more of the aqueous composition to be treated.
In this specification, the fluorine-containing polymer concentration (P) is determined by measuring about 1 g (Xg) of a sample in an aluminum cup having a diameter of 5 cm, heating at 100 ° C. for 1 hour, and further heating at 300 ° C. for 1 hour. From the minute (Zg), it is calculated from the formula: P = (Z / X) × 100 (%).

The fluorine-containing polymer is not particularly limited, but is polytetrafluoroethylene [PTFE], tetrafluoroethylene [TFE] / hexafluoropropylene [HFP] copolymer [FEP], TFE / perfluoro (alkyl vinyl ether) [PAVE]. ] Copolymer [PFA], Ethylene / TFE copolymer [ETFE], Polyvinylidene fluoride [PVDF], Polychlorotrifluoroethylene [PCTFE] and the like.
The PTFE may be a tetrafluoroethylene [TFE] homopolymer or a modified polytetrafluoroethylene [modified PTFE]. In the present specification, the modified PTFE means a non-melt processable fluorine-containing polymer obtained by polymerizing TFE and a small amount of monomer. Examples of the trace monomer include fluoroolefins such as HFP and chlorotrifluoroethylene [CTFE], fluoro (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; Fluorodioxole; perfluoroalkylethylene; ω-hydroperfluoroolefin and the like.
As a fluorine-containing polymer in the said to-be-processed aqueous composition, a perfluoropolymer is preferable and especially a TFE homopolymer and modified PTFE are more preferable.

The above-mentioned aqueous composition to be treated may be obtained by any method as long as it contains the above-mentioned organic acid compound, nonionic surfactant and aqueous medium, and optionally a fluorine-containing polymer.
The said to-be-processed aqueous composition can be obtained as a waste liquid produced, for example, when the fluoropolymer aqueous dispersion obtained by polymerization is concentrated.
The aqueous composition to be treated removes, for example, a fluoropolymer concentrated aqueous dispersion obtained by concentrating a fluoropolymer aqueous dispersion obtained by polymerization by a phase separation concentration method, an ultrafiltration method and / or an electric concentration method. Can be obtained. The treated aqueous composition corresponds to the remaining aqueous composition obtained by separating and removing the fluoropolymer concentrated aqueous dispersion from the fluoropolymer aqueous dispersion obtained by polymerization.

In the present invention, the polymerization can be generally performed in an aqueous medium in the presence of an emulsifier, and is preferably performed in the presence of the organic acid compound described above.
It does not specifically limit as a fluorine-containing monomer used in the said superposition | polymerization, For example, TFE, HFP, PAVE, vinylidene fluoride [VDF], CTFE etc. are mentioned. The polymerization may use not only fluorine-containing monomers but also fluorine-free monomers such as ethylene.
In the present invention, in the polymerization, reaction conditions such as temperature, pressure, and emulsifier concentration can be appropriately set according to the type, amount, etc. of the target fluorine-containing polymer.
In the fluoropolymer aqueous dispersion obtained by the polymerization, the fluoropolymer is generally 5 to 40% by mass, and more preferably 15 to 35% by mass.

The phase separation concentration method, the ultrafiltration method and the electric concentration method are not particularly limited, and conventionally known methods can be used.
Examples of the phase separation method include, for example, the method described in US Pat. No. 3,037,953. Examples of the ultrafiltration method include, for example, the method described in Japanese Examined Patent Publication No. 2-34971, as an electric concentration method. Can include, for example, the method described in British Patent No. 642025.

In the present invention, “concentrated by phase separation concentration method, ultrafiltration method and / or electric concentration method” means at least one of phase separation concentration method, ultrafiltration method and electric concentration method. This means that each concentration method may be performed only once, or may be repeated twice or more. In the case of performing a combination of two or more methods, each method may be performed alternately once or twice or after any one method is performed once or twice or more. Other methods may be performed once or twice or more.
As the aqueous composition to be treated, a product obtained by concentrating a fluoropolymer aqueous dispersion obtained by polymerization by increasing the nonionic surfactant concentration may be used.

The above-mentioned fluoropolymer concentrated aqueous dispersion generally has a fluoropolymer content of 20 to 75% by mass.

Nonionic surfactant aqueous composition production method of the present invention,
(1) adding a specific compound to the aqueous composition to be treated, and
(2) A method including a step of performing contact treatment comprising contact with activated carbon and / or contact with a cation exchange resin on the primary treatment aqueous composition obtained by the step (1).

The specific compound in the step (1) is an inorganic ion compound composed of a cation that forms a water-insoluble salt with the organic acid compound, or a basic compound that forms a water-insoluble salt or a water-insoluble coordination product with the organic acid compound. It is an organic compound.
In the step (1), any one of the specific compounds may be added, or two or more may be added.

The inorganic ion compound is not particularly limited as long as it comprises a cation that forms a water-insoluble salt with the organic acid compound, and examples thereof include polyvalent metal salts.
Examples of the polyvalent metal that forms the polyvalent metal salt include Al, Ca, and Mg.
Among the above-mentioned inorganic ionic compounds, Al (OH) ₃ , Al ₂ (SO ₄ ) ₃ , CaCl _{2 and the} like are preferable.

The basic organic compound is not particularly limited as long as it forms a water-insoluble salt or a water-insoluble coordination product with the organic acid compound.
Examples of the basic organic compound in the present invention include organic compounds having —C (—NHR ³ ) ═NH in the molecular structure. The compound having a basic skeleton represented by —C (—NHR ³ ) ═NH may be an acid salt, but the position of the double bond in the basic skeleton can move depending on the liquidity of the existing environment. It may be. In the above formula, R ³ is as defined below, that is, H represents an optionally substituted hydrocarbon group or H.

Examples of the basic organic compound in the present invention include the following general formula (i):
^{Q-C (-NHR 3) =} NH (i)
(In the formula, Q represents R ² S—, R ¹² O—, R ¹³ R ¹⁴ N— or R ² —, R ³ and R ¹² represent H or R ² , and R ¹³ and R ¹⁴ represent , The same or different and each represents H or R ² , and R ² represents a hydrocarbon group optionally substituted with H.) or a salt thereof.
The compound represented by the general formula (i) is an isothiourea compound when Q in the general formula (i) is R ² S—, an isourea compound when Q is R ¹² O—, and Q is R ^When it is ¹³ R ¹⁴ N—, it may be called a guanidine compound, and when Q is R ² —, it may be called an amidine compound.

Examples of the acid forming the acid salt of the compound represented by the general formula (i) include HX (X represents Cl or Br), H ₂ SO _{4 and the} like.
The acid salt of the amidine compound is usually
Q—C (—NHR ³ ) ═NH · HX or [Q—C (—NHR ³ ) ═NH] ₂ .H ₂ SO ₄
(Q, R ³ and X are as defined above).

In the general formula (i), when Q is R ¹² O— or R ² S—, for example, the following general formula (II)
_{^{R 2 -Y-C (-NH 2}} ) = NH · HX (II)
(Wherein R ² represents a hydrocarbon group optionally substituted with H, Y represents O or S, and X represents Cl or Br). It may be a compound.
In the present specification, “iso (thio) urea compound” represents a concept that summarizes “isourea compound or isothiourea compound”, which means that Y in the general formula (II) represents O or S. It is clear from the definition.
In this specification, as the iso (thio) urea compound represented by the general formula (II), for example,

Etc. R ² and X in the above formula are as defined above.

The hydrocarbon group as R ² preferably has 1 to 25 carbon atoms.
The hydrocarbon group as R ² is preferably a hydrocarbon group containing an aryl group or an alkyl group having 1 to 3 carbon atoms, and preferably an arylalkyl group or an ethyl group.
The aryl group that can be contained in R ² may be one in which at least one, usually 1 to 2 H atoms are substituted with a substituent, and examples of the substituent include a nitro group. It is done.
R ² is preferably —CH ₂ —Ar (wherein Ar represents a phenyl group which may have 1 to 2 substituents) or an ethyl group. As the substituent that the phenyl group may have, a nitro group is preferable. R ² is more preferably —CH ₂ —Ph (Ph represents a phenyl group).

Y in the general formula (II) represents O or S, but is preferably S.

Examples of the iso (thio) urea compound represented by the general formula (II) include benzylisothiourea hydrochloride [C ₆ H ₅ CH ₂ SC (NH ₂ ) NH · HCl],

S- (p-nitrobenzyl) isothiourea hydrochloride represented by

S- (2,4-dinitrobenzyl) isothiourea hydrochloride represented by the formula is preferable, and among them, benzylisothiourea hydrochloride is more preferable.

The hydrocarbon group as R ² in the above general formula (i) is preferably a hydrocarbon group having 1 to 25 carbon atoms, like R ² in the above general formula (II), and is a hydrocarbon group or carbon containing an aryl group It is more preferable that it is a C1-C3 alkyl group. The “hydrocarbon group containing an aryl group” may be an aryl group alone or an arylalkyl group (aralkyl group).
In the general formula (i), examples of the substituent in the hydrocarbon group as R ² include a halogen atom such as F, a heteroatom such as oxygen, and the like when the hydrocarbon group is an alkyl group. When the hydrocarbon group is the above “hydrocarbon group containing an aryl group”, for example, a nitro group and the like can be mentioned.

In general formula (i), when Q is R ¹² O— and R ¹² is R ² , the above general formula (II) (provided that Y is O. R ² and X are As defined, the isourea compound represented by R ² as R ¹² in the general formula (i) is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.
In the above general formula (i), when Q is R ¹³ R ¹⁴ N—, R ² in R ¹³ and R ¹⁴ is preferably an aryl group or an alkyl group having 1 to 3 carbon atoms. A group and a methyl group are more preferable.
In the above general formula (i), when Q is R ² —, R ² is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.
In the general formula (i), Q is preferably R ¹² O—, R ¹³ R ¹⁴ N—, or R ² —, and more preferably R ¹² O— or R ¹³ R ¹⁴ N—. .

Specific compounds used in the present invention include 1,1-dimethylguanidine sulfate [(CH ₃ ) ₂ NC (—NH ₂ ) ═NH] ₂ .H ₂ SO ₄ , guanidine hydrochloride, in addition to the above-mentioned isothiourea compound. Guanidine compounds (R ¹³ R ¹⁴ NC (—NHR ³ ) such as salt (NH═C (NH ₂ ) ₂ .HCl), 1,3-diphenylguanidine (C ₆ H ₅ NHC (—NHC ₆ H ₅ ) ═NH) ) = NH); acetamidine compounds (R ² C (—NH ₂ ) ═NH) such as acetamidine hydrochloride (CH ₃ C (—NH ₂ ) ═NH · HCl); O-methylisourea sulfate ( An isourea compound (R ¹² OC (—NH ₂ ) ═NH) such as CH ₃ OC (—NH ₂ ) ═NH · 1/2 H ₂ SO ₄ ) is preferred.

In the step (1), the specific compound can be appropriately determined according to the amount of the organic acid compound to be removed, but it is preferable to add an excessive amount to the organic acid compound in terms of removal efficiency. The amount of the specific compound added is preferably 1 to 20 mol, more preferably 1 to 10 mol, per mol of the organic acid compound in the aqueous composition to be treated.
When the said specific compound is an inorganic ion compound, it is preferable that the addition amount is the ratio of 1-20 mol with respect to 1 mol of organic acid compounds in a to-be-processed aqueous composition. When the said specific compound is a basic organic compound, it is preferable that the addition amount is the ratio of 1-20 mol with respect to 1 mol of organic acid compounds in a to-be-processed aqueous composition.
The step (1) preferably includes an operation of appropriately stirring after adding the specific compound in terms of improving the removal efficiency of the organic acid compound.

In the step (1), a water-insoluble salt or a water-insoluble coordination product derived from the specific compound and the organic acid compound can generally be formed by adding the specific compound having the above-described properties. Therefore, step (1) makes it possible to reduce the content of the organic acid compound in the aqueous composition to be treated simply and inexpensively.
The step (1) generally includes an operation of removing the water-insoluble salt or water-insoluble coordination product formed by adding the specific compound from the aqueous composition by a technique such as filtration or decantation. Good.

The primary treatment aqueous composition obtained by the step (1) is preferably obtained by adding an excess amount of the specific compound to the organic acid compound as described above, and is derived from the specific compound and the organic acid compound and water. Contains surplus that does not form insoluble matter. Examples of the surplus include a cation derived from an inorganic ion compound, a basic organic compound that does not form a water-insoluble salt or a water-insoluble coordination product with an organic acid compound, and the like. The surplus depends on the content of the organic acid compound in the aqueous composition to be treated, the amount of the specific compound added, etc., but is usually 0.1 to 1.5% by mass of the mass of the primary aqueous treatment composition.
In the present specification, the concentration of the surplus derived from a specific compound is a value measured by inductively coupled plasma emission spectroscopy (ICP-MS) in the case of an inorganic compound, and HPLC measurement in the case of a basic organic compound. Is the value obtained by

The manufacturing method of this invention includes the process (2) which performs the contact process which consists of a contact with activated carbon and / or a contact with a cation exchange resin with respect to the primary process aqueous composition obtained by the said process (1).
By the step (2), the cation and the basic organic compound which are surplus not forming the water-insoluble matter with the organic acid compound can be removed from the primary treatment aqueous composition. A nonionic surfactant aqueous composition having a reduced content of the compound can be obtained.

The contact with activated carbon in the above step (2) does not cause clogging such as clogging that may occur when contacting an ultrafiltration membrane, etc., can be used repeatedly, is efficient and economical, and increases the processing speed. You can also.
The activated carbon used in the above step (2) may be an effective amount, and depends on the properties of the activated carbon used, contact conditions, etc., but is generally 0.1 to 100 parts by mass with respect to 100 parts by mass of the aqueous composition to be treated. Preferably there is. A more preferable lower limit of the effective amount of activated carbon with respect to 100 parts by mass of the aqueous composition to be treated is 1 part by mass, a further preferable lower limit is 2 parts by mass, and a more preferable upper limit is 50 parts by mass.

The activated carbon is preferably one from which fine particles have been removed before contacting the aqueous composition to be treated. The method for removing the fine particles is not particularly limited, and can usually be easily and sufficiently removed by washing with water.
In the present invention, the activated carbon is reactivated by heat treatment at 100 to 400 ° C. for about 1 to 24 hours, and further immersed in water such as ion-exchanged water for several hours or more after the heat treatment, and bubbles in the pores It is preferable to carry out a normal pretreatment such as removal of.

In the present invention, the contact with the activated carbon is preferably a method based on circulating the aqueous composition to be treated through the activated carbon packed in the column in that the aqueous composition after the treatment can be easily recovered. When contact with activated carbon is carried out using a column, the flow rate of the aqueous composition to be treated to the column can be appropriately adjusted according to the usual method of column use, depending on the type of fluoropolymer, solid content, etc. it can.

Examples of the cation exchange resin used in the step (2) include a strong acid cation exchange resin having a —SO ₃ ^— group as a functional group, a weak acid cation exchange resin having a —COO ^— group as a functional group, and the like. Among them, known ones are mentioned, and among them, a strong acid cation exchange resin is preferable and an H ⁺ type strong acid cation exchange resin is more preferable in terms of good adsorptivity with an amine compound described later.
As the cation exchange resin, it is preferable to use a Na-type resin that has been treated with a 1M HCl aqueous solution to form H ⁺ and washed thoroughly with pure water.
Conditions for the contact with the cation exchange resin can be set as appropriate according to the type and amount of cation exchange resin used, but the space velocity [SV] should be 0.5 to 10. Is preferred.

The nonionic surfactant aqueous composition obtained from the method of the present invention comprises the above-described nonionic surfactant and an aqueous medium, and generally the amount of the nonionic surfactant is 0.1 to 30. It is what is mass%.
In the nonionic surfactant aqueous composition, the preferable lower limit of the amount of the nonionic surfactant is 0.5% by mass, and may be 25% by mass or less within the above range. .
The nonionic surfactant concentration of the nonionic surfactant aqueous composition in the present invention is preferably 0.1 to 30% by mass as described above, but evaporation or membrane concentration, phase separation using a cloud point, etc. It can also be enhanced by a concentration operation using a known method. When the concentration is performed, the nonionic surfactant concentration can be 10 to 100% by mass of the aqueous nonionic surfactant composition, and for example, 30 to 100% by mass is preferable. A nonionic surfactant aqueous composition adjusted to an appropriate concentration can also be used as a dispersant for known purposes such as concentration and stabilization. For example, it can be reused by adding it to a fluoropolymer aqueous dispersion. Can be used.

In the nonionic surfactant aqueous composition obtained from the method of the present invention, the content of the organic acid compound is preferably 100 ppm or less, more preferably 50 ppm or less, more preferably the nonionic surfactant aqueous composition. Is 10 ppm or less.

The nonionic surfactant aqueous composition obtained by the method of the present invention is obtained by removing the excess cation and basic organic compound produced in step (1) in step (2).
The total concentration of the excess cation and basic organic compound can be reduced to 100 ppm or less of the mass of the nonionic surfactant aqueous composition, and the preferred upper limit is 50 ppm, within the above range. If there is, the lower limit may be 10 ppm in terms of removal efficiency.
When the concentration of the excess cation or basic organic compound exceeds 100 ppm of the mass of the aqueous nonionic surfactant composition, the fluorine-containing polymer added when the nonionic surfactant is reused as a stabilizer In some cases, aggregation of the aqueous dispersion may be caused, and in some cases, deterioration of physical properties of a coating obtained by using the fluoropolymer aqueous dispersion for coating, impregnation, or the like may be caused.

As described above, the method for producing an aqueous nonionic surfactant composition of the present invention has a low concentration of organic acid compound, and an excess cation or basic organic compound that does not form a water-insoluble matter with the organic acid compound. Nonionic surfactant aqueous composition having a sufficiently high nonionic surfactant content can be prepared while keeping the concentration of the non-ionic surfactant low, for example, waste liquid generated by concentration, purification, etc. of an aqueous fluoropolymer dispersion It can be used as a method of reusing the nonionic surfactant in the inside. The production method of the present invention removes the organic acid compound by a simple operation at a lower cost than the conventional purification method using an anion exchange resin, and further, an unnecessary residue of the specific compound added for the removal. It is also a method to remove.

Since the nonionic surfactant aqueous composition production method of the present invention has the above-described configuration, the nonionic surfactant has a high nonionic surfactant content and a low concentration of excess cation and basic organic compound. The aqueous surfactant composition can be easily prepared at low cost.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to these examples.

In this example, “part” represents “part by mass” unless otherwise specified.
-The measurement performed in each Example was performed with the following method.
1. Nonionic surfactant content (N)
About 1 g (X) of a sample was taken in an aluminum cup having a diameter of 5 cm, dried at 100 ° C. for 1 hour, and further dried at 300 ° C. for 1 hour, based on the heating residue (Z), the formula: N = (1-Z / X ) × 100 (%).
2. Content of Al ion and guanidine compound Al ion was measured by inductively coupled plasma optical emission spectrometry (ICP-MS) (measuring instrument SPQ9000, manufactured by Seiko) under the following conditions. The guanidine compound was acetonitrile / 0.6 mass as a developing solution. % Perchloric acid aqueous solution = 1/1 (vol / vol%) was determined by HPLC measurement using ODS-120T (4.6φ × 250 mm, manufactured by Tosoh Corporation).
ICP-MS (Inductively Coupled Plasma Mass Spectrometry)
Equipment: SPQ9000
Introduction: Microflow nebulizer PFA-ICP1000
Ion introduction condition High frequency output 0.9kW
Carrier gas (argon): 0.96 L / min
Plasma gas (argon): 16.0 L / min
Auxiliary gas (argon): 1.0 L / min
Measurement conditions Number of divisions 8
Mass range 27
2. Number of repetitions 3 times Fluorine-containing surfactant concentration
It is a value determined by ¹⁹ F-NMR (measuring instrument AC300P, manufactured by Bruker Biospin).

Example 1
To 40 g of an aqueous composition to be treated having a pH of 7 containing 1% Neugen TDS-80 (polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) and 1500 ppm ammonium perfluorooctanoate [PFOA], aluminum sulfate 0.9 g of 27% aqueous solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained 670 ppm of PFOA and 910 ppm of Al ions.
Pass the primary treated aqueous composition through a column (20 mm in diameter) packed with 25 ml of cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4. Thus, a nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had a Neugen TDS-80 of 1%, a PFOA of 670 ppm, and an Al ion of 15 ppm.

Example 2
Neugen TDS-80 (polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) 1%, PFOA 1500 ppm, pH 4 adjusted to 10 with NH ₃ aqueous solution, 40 g of sulfuric acid 0.9 g of 27% aluminum solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained 500 ppm of PFOA and 900 ppm of Al ions.
By passing the primary treated aqueous composition through a column (diameter 20 mm) packed with 25 ml of a cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4, A nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had Neugen TDS-80 of 1%, PFOA of 500 ppm, and Al ions of 10 ppm.

Example 3
To 40 g of aqueous composition to be treated containing 1% Neugen TDS-80 (polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) and 1500 ppm PFOA, adjusted to pH 3 with aqueous HCl solution, aluminum sulfate 0.9 g of 27% aqueous solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained 560 ppm of PFOA and 900 ppm of Al ions.
By passing the primary treated aqueous composition through a column (diameter 20 mm) filled with 25 ml of a cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4. A nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had Neugen TDS-80 of 1%, PFOA of 560 ppm, and Al ions of 10 ppm.

Example 4
To 40 g of an aqueous composition to be treated having a pH of 7 containing 5% Neugen TDS-80 (polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) and 1500 ppm ammonium perfluorooctanoate [PFOA], 1 g of 1-dimethylguanidine sulfate 1% aqueous solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained PFOA below the detection limit and 1,700 dimethylguanidine sulfate at 5700 ppm.
Pass the primary treated aqueous composition through a column (20 mm in diameter) packed with 25 ml of cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4. Thus, a nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had Neugen TDS-80 of 1%, PFOA was below the detection limit, and 1,1-dimethylguanidine sulfate was 50 ppm.

Example 5
To 40 g of an aqueous composition to be treated having a pH of 3 containing 5% of Neugen TDS-80 (polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) and 1500 ppm of ammonium perfluorooctanoate [PFOA], 1 g of 1-dimethylguanidine sulfate 1% aqueous solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained PFOA below the detection limit and 1,700 dimethylguanidine sulfate at 5700 ppm.
Pass the primary treated aqueous composition through a column (20 mm in diameter) packed with 25 ml of cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4. Thus, a nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had Neugen TDS-80 of 1%, PFOA was below the detection limit, and 1,1-dimethylguanidine sulfate was 50 ppm.

Example 6
To 40 g of an aqueous composition to be treated having a pH of 10 containing 5% Neugen TDS-80 (a polyoxyethylene alkyl ether type nonionic surfactant manufactured by Daiichi Pharmaceutical Co., Ltd.) and 1500 ppm of ammonium perfluorooctanoate [PFOA], 1 g of 1-dimethylguanidine sulfate 1% aqueous solution was added and stirred well. After stirring, the mixture was filtered using 110 nm filter paper. The obtained primary treatment aqueous composition contained PFOA below the detection limit and 1,700 dimethylguanidine sulfate at 5700 ppm.
Pass the primary treated aqueous composition through a column (20 mm in diameter) packed with 25 ml of cation exchange resin (product name: Amberlite IRA120B, manufactured by Rohm and Haas) under the conditions of a temperature of 40 ° C. and SV4. Thus, a nonionic surfactant aqueous composition was obtained. The obtained nonionic surfactant aqueous composition had Neugen TDS-80 of 1%, PFOA was below the detection limit, and 1,1-dimethylguanidine sulfate was 50 ppm.

From this example, it was found that the production method of the present invention can provide a nonionic surfactant aqueous composition having a low concentration of Al ions or guanidine compounds.

Since the nonionic surfactant aqueous composition production method of the present invention has the above-described configuration, the nonionic surfactant has a high nonionic surfactant content and a low concentration of excess cation and basic organic compound. Since an aqueous agent composition can be easily prepared at low cost, for example, it can be used as a method for reusing a nonionic surfactant in a waste liquid generated by concentration, purification, etc. of an aqueous fluoropolymer dispersion. it can. In addition, since the above-mentioned nonionic surfactant aqueous composition has a low concentration of excess cation and basic organic compound, a problem of causing interaction with dispersoids when added as a dispersant was added. There is no problem of deteriorating the physical properties of the coating obtained by using the fluoropolymer aqueous dispersion for coating, impregnation and the like.

Claims (13)

A nonionic interface for producing a nonionic surfactant aqueous composition using an aqueous composition to be treated which comprises an organic acid compound, a nonionic surfactant and an aqueous medium and the content of the fluorine-containing polymer is 5% by mass or less A method for producing an aqueous active agent composition comprising:
The nonionic surfactant aqueous composition production method comprises:
(1) adding a specific compound to the aqueous composition to be treated, and
(2) A method comprising a step of performing a contact treatment comprising contact with activated carbon and / or contact with a cation exchange resin on the primary treatment aqueous composition obtained by the step (1),
The specific compound is an inorganic ionic compound composed of a cation that forms a water-insoluble salt with the organic acid compound, or a basic organic compound that forms a water-insoluble salt or a water-insoluble coordination product with the organic acid compound,
The organic acid compound has the following general formula (I)
R ¹ -Z (I)
(In the formula, R ¹ represents a linear or branched hydrocarbon group that may have a hetero atom and H may be substituted with F, F or H, and Z represents —COOM ¹ , — SO ₃ M ¹ or a phosphoric acid-derived group, and M ¹ represents H, NH ₄ , Na, or K.) A method for producing a nonionic surfactant aqueous composition. The basic organic compound has the following general formula (i)
^{Q-C (-NHR 3) =} NH (i)
(In the formula, Q represents R ² S—, R ¹² O—, R ¹³ R ¹⁴ N— or R ² —, R ³ and R ¹² represent H or R ² , and R ¹³ and R ¹⁴ represent Or the same or different and represents H or R ² , wherein R ² represents a hydrocarbon group which may be substituted.) Or a non-ionic salt thereof. A method for producing a surfactant aqueous composition. In the basic organic compound, Q in the general formula (i) is R ¹² O—, R ¹³ R ¹⁴ N— or R ² — (R ¹² , R ¹³ , R ¹⁴ and R ² are as defined above). A compound or its acid salt,
The method for producing an aqueous nonionic surfactant composition according to claim 2, wherein the acid forming the acid salt is HX (X represents Cl or Br) or H ₂ SO ₄ . The method for producing an aqueous nonionic surfactant composition according to claim 1, wherein the inorganic ionic compound is a polyvalent metal salt. The method for producing an aqueous nonionic surfactant composition according to claim 4, wherein the polyvalent metal forming the polyvalent metal salt is Al, Ca, or Mg. 6. The nonionic surfactant aqueous solution according to claim 1, wherein the specific compound is added at a ratio of 1 to 20 moles per mole of the organic acid compound in the aqueous composition to be treated in step (1). Composition manufacturing method. The method for producing an aqueous nonionic surfactant composition according to claim 1, wherein the organic acid compound has an average molecular weight of 1000 or less. The organic acid compound has 4 to 12 carbon atoms, The method for producing a nonionic surfactant aqueous composition according to claim 1, 2, 3, 4, 5, or 6. The method for producing an aqueous nonionic surfactant composition according to claim 1, wherein the organic acid compound is a fluorine-containing surfactant. The method for producing an aqueous nonionic surfactant composition according to claim 9, wherein the aqueous nonionic surfactant composition has a fluorine-containing surfactant content of 100 ppm or less of the aqueous nonionic surfactant composition. The aqueous composition to be treated is obtained by removing the fluoropolymer concentrated aqueous dispersion obtained by concentrating the fluoropolymer aqueous dispersion obtained by polymerization by the phase separation concentration method, ultrafiltration method and / or electric concentration method. The method for producing an aqueous nonionic surfactant composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. The method for producing an aqueous nonionic surfactant composition according to claim 11, wherein the polymerization is performed in the presence of a fluorine-containing surfactant. The method for producing an aqueous nonionic surfactant composition according to claim 9, 10 or 12, wherein the fluorine-containing surfactant is perfluorocarboxylic acid or a salt thereof.