JP2016074830A - Hydrophilic oil repellent solution, surface coating material, coating film, resin composition, oil and water separation filter medium and porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel hydrophilic oil repellent solution having excellent hydrophilic oil repellency.SOLUTION: Selected is a hydrophilic oil repellent solution that is a perfluoropolyether group-containing compound, comprising an oil repellency imparting group and a hydrophilic imparting group in a molecule.SELECTED DRAWING: None

Description

  The present invention relates to a hydrophilic oil repellent, a surface coating material, a coating film, a resin composition, an oil / water separation filter medium, and a porous body.

  In general, as an antifouling technique, it is desirable to impart oil repellency for making it difficult to adhere dirt and hydrophilicity that allows the attached dirt to be easily removed by washing with water. As a technique for imparting hydrophilicity to the surface of a substrate, a method is known in which titanium oxide or the like is fixed, and dirt adhered by superhydrophilization by the action of a photocatalyst is washed away (Patent Document 1).

  However, when a photocatalyst film is used, there is a problem that the function of preventing the adhesion of dirt is not sufficient, although the function of easily removing dirt is obtained. In particular, in an environment where sufficient light required for the expression of the photocatalytic function cannot be obtained, sufficient antifouling properties may not be obtained.

  On the other hand, as a technique for imparting oil repellency to the substrate surface, a fluorine-based compound is mainly used. As a fluorine-based compound, a method using a fluorine resin such as polytetrafluoroethylene (PTFE) or a compound having a perfluoroalkyl group in a molecule as a surface treating agent is known. As with a general hydrophobic coating film, water repellency is high, and there is a problem that oil stains adhering to the surface are difficult to remove by wiping or washing with water. In particular, when used in an environment where water is applied, there is a problem that oil stains are easily attached.

  In order to make the surface of the fluororesin hydrophilic, a fluororesin that has been subjected to plasma surface treatment, flame treatment, ozone treatment, etc. on the outer surface has been proposed (Patent Document 2). However, when hydrophilicity is imparted, an oil repellent function cannot be obtained, and the fluororesin has a problem that it is difficult to apply and process the substrate surface.

  From the above, in order to impart a sufficient antifouling function to an object to be processed such as a substrate, a hydrophilic oil repellent that simultaneously exhibits excellent hydrophilicity and oil repellency has been desired. An excellent hydrophilic oil repellent is useful in a wide range of applications such as quick-drying of water with improved wettability, anti-fogging properties, and oil-water separation properties in addition to antifouling function, but especially for oil-water separation properties. Useful in.

  However, there is no compound that exhibits both excellent hydrophilicity and oil repellency at the same time in conventional compounds, and it has been difficult to impart sufficient antifouling function and oil / water separation function.

JP 09-227160 A Japanese Patent Laid-Open No. 05-177766

  The present invention has been made in view of the above circumstances, and provides a novel hydrophilic oil repellant having excellent hydrophilic oil repellency, and a surface coating material, a coating film, and a resin composition containing the hydrophilic oil repellant. It is an object to provide a product, an oil / water separation filter medium, and a porous body.

  By the way, when a fluorine compound is used as a surface treating agent, the treated surface usually exhibits water and oil repellency, and the water repellency generally increases as the carbon number of the fluorine structure increases. However, as a result of intensive studies by the inventors of the present application, in a compound in which a hydrophilicity-imparting group is added to a specific perfluoropolyether group-containing compound, a unique characteristic that cannot be realized by a conventional fluorine compound called hydrophilic oil repellency The present invention has been completed by finding that a compound having a large number of carbon atoms in a fluorine structure exhibits both excellent hydrophilicity and oil repellency at the same time.

That is, the present invention has the following configuration.
[1] A hydrophilic oil repellent which is a perfluoropolyether group-containing compound represented by the following general formula (1).
Rf ¹ -Rfo-Rf ² -X (1)
In the general formula (1), Rf ¹ is a C 1-6 perfluoroalkoxy group or a fluorine atom. Rfo is a divalent perfluoropolyether group. Further, Rf ² is a 1 to 20 carbon atoms, a linear or branched perfluoroalkyl group.
X is any one hydrophilicity-imparting group selected from the group consisting of anionic, cationic and amphoteric types.

[2] A hydrophilic oil repellent which is a perfluoropolyether group-containing compound represented by the following formula (2).
^{Rf 1 -Rfo-Rf 2 -R-} X ··· (2)
In the general formula (2), Rf ¹ is a C 1-6 perfluoroalkoxy group or a fluorine atom. Rfo is a divalent perfluoropolyether group. Further, Rf ² is a 1 to 20 carbon atoms, a linear or branched perfluoroalkyl group.
R is a divalent organic group and is a linear or branched linking group.
X is any one hydrophilicity-imparting group selected from the group consisting of anionic, cationic and amphoteric types.

[3] The hydrophilic oil repellent according to item 2 above, wherein R includes one or more bonds selected from an ether bond, an ester bond, an amide bond and a urethane bond in the molecular chain.

[4] Any one of items 1 to 3, including two or more perfluoropolyether group-containing compounds selected from the group consisting of the perfluoropolyether group-containing compounds represented by the above formula (1) and the above formula (2). The hydrophilic oil repellent agent described in 1.

[5] X in the above formula (1) or the above formula (2) has “—CO ₂ M ¹ ” or “—SO ₃ M ¹ ”, “—OSO ₂ M ¹ ”, “—OP (OH) at the terminal. ) O ₂ M ¹ ”,“ —OPO ₃ M ¹ ₂ ”or“ ═O ₂ PO ₂ M ¹ ”(M ¹ is an alkali metal, alkaline earth metal, Mg, Al, R ¹ R ² R ³ R ⁴ Any one of the preceding items 1 to 4, which is an anionic hydrophilic imparting group having N ⁺ ; R ^{1 to} R ⁴ each having a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms. The hydrophilic oil repellent according to one item.
[6] X in the above formula (1) or the above formula (2) is “-N ⁺ R ⁵ R ⁶ R ⁷ .Cl ⁻ ” or “—N ⁺ R ⁵ R ⁶ R ⁷ .Br ⁻ ” at the terminal. ^{"- N + R 5 R 6 R} 7 · I - " ^{"- N + R 5 R 6 R} 7 · CH 3 SO 3 - ," ^{"- N + R 5 R 6 R} 7 · NO 3 - ", ^{"(-N + R 5 R 6 R} 7) 2 CO 3 2- " or ^{"(-N + R 5 R 6 R} 7) 2 SO 4 2- " ^(R 5 to R ⁷ is independently hydrogen atom or each The hydrophilic oil-repellent agent according to any one of the preceding items 1 to 4, which is a cationic hydrophilic imparting group having a linear or branched alkyl group having 1 to 20 carbon atoms.
[7] X in the above formula (1) or the above formula (2) is terminally represented by carboxybetaine type “—N ⁺ R ⁸ R ⁹ (CH ₂ ) _n CO ₂ ⁻ ”, sulfobetaine type “— N ⁺ R ⁸ R ⁹ (CH ₂ ) _n SO ₃ ⁻ ”or amine oxide type“ —N ⁺ R ⁸ R ⁹ O ⁻ ”(n is an integer of 1 to 5, R ⁸ and R ⁹ are hydrogen atom or carbon 5. The hydrophilic oil repellent according to any one of 1 to 4 above, which is an amphoteric hydrophilic imparting group having an alkyl group of formula 1 to 10.

[8] The hydrophilic oil repellent and the solvent according to any one of 1 to 4 above,
The surface coating material whose mass composition ratio of the said hydrophilic oil repellent and the said solvent is the range of 0.2: 99.8-50: 50.
[9] The surface covering material according to item 8, wherein the solvent is water, alcohol, or a mixture of water and alcohol.
[10] Furthermore, a binder is included,
10. The surface covering material according to item 8 or 9, wherein the mass composition ratio of the hydrophilic oil repellent and the binder is in the range of 10:90 to 99.9: 0.1.
[11] The surface covering material according to any one of items 8 to 10, wherein the binder is a resin.
[12] The surface covering material according to any one of items 8 to 10, wherein the binder is a water-soluble resin.
[13] The surface covering material according to any one of items 8 to 10, wherein the binder is water glass.

[14] A coating film comprising the hydrophilic oil repellent according to any one of items 1 to 4 above.
[15] Furthermore, a binder is included,
15. The coating film according to item 14, wherein the mass composition ratio of the hydrophilic oil repellent and the binder is in the range of 10:90 to 99.9: 0.1.

[16] The hydrophilic oil-repellent agent according to any one of items 1 to 4 and a resin,
The resin composition whose mass composition ratio of the said hydrophilic oil repellent and the said resin is the range of 10: 90-99.9: 0.1.

[17] An oil-water separation filter medium comprising the coating film according to the above item 14 or 15, or the resin composition according to the above item 16.

[18] A porous body comprising the hydrophilic oil repellent according to any one of 1 to 4 above.
[19] A porous body in which the hydrophilic oil repellent according to any one of 1 to 4 above is bonded with a resin.
[20] A porous body in which the hydrophilic oil-repellent agent according to any one of 1 to 4 above is bonded with vitreous.

  The hydrophilic oil repellent of the present invention has an excellent structure because it has an oil repellency-imparting group containing a perfluoropolyether group and any one of anionic, cationic and amphoteric hydrophilic imparting groups in the molecule. It is a material having hydrophilic oil repellency and has applicability to a wide variety of uses. In particular, it is a material suitable for oil / water separation.

  Hereinafter, a hydrophilic oil repellent which is an embodiment to which the present invention is applied will be described in detail together with a surface coating material, a coating film, a resin composition, an oil / water separation filter medium and a porous body containing the same.

<Hydrophilic oil repellent>
First, the structure of the hydrophilic oil repellent which is one embodiment to which the present invention is applied will be described.
Specifically, the hydrophilic oil repellent of the present embodiment is represented by the perfluoropolyether group-containing compound represented by the following formula (1) or the following formula (2), or the above formula (1) and the above formula (2). It is a mixture containing two or more perfluoropolyether group-containing compounds selected from the group consisting of perfluoropolyether group-containing compounds.

Rf ¹ -Rfo-Rf ² -X (1)

^{Rf 1 -Rfo-Rf 2 -R-} X ··· (2)

In the general formula (1) or the general formula (2), Rf ¹ is a C 1-6 perfluoroalkoxy group or a fluorine atom. Further, Rf ² is a perfluoroalkylene group having 1 to 20 carbon atoms, may be linear or branched.

  In the general formula (1) or the general formula (2), Rfo is a divalent perfluoropolyether group. Here, the perfluoropolyether group is a poly (oxyperfluoroalkylene) group having an oxyperfluoroalkylene unit. The poly (oxyperfluoroalkylene) group may be composed of only one oxyperfluoroalkylene unit or may be composed of two or more oxyperfluoroalkylene units having different carbon numbers.

The oxyperfluoroalkylene unit is an oxyperfluoroalkylene unit having 1 to 10 carbon atoms. Specifically, for example, [CF ₂ O] _e , [CF ₂ CF ₂ O] _g , and [CF ₂ CF ₂ CF _{2]. O] h, [CF (CF} 3) CF 2 O] j, include _{[CF 2 CF 2 CF 2 CF} 2 O] k and the like. Here, e, g, h, j, and k in the oxyperfluoroalkylene unit are each independently an integer of 0 or more. The total number of oxyperfluoroalkylene groups (for example, e + g + h + j + k in the above specific example) is an integer of 1 to 50 when Rf ¹ is a perfluoroalkoxy group, and more preferably an integer in the range of 1 to 15. More preferably, it is an integer in the range of 1-6. When Rf ¹ is a fluorine atom, it is preferably an integer of 2 to 50, more preferably an integer in the range of 2 to 15, and still more preferably an integer in the range of 2 to 6. Moreover, the coupling | bonding order of each unit is not limited.

In the hydrophilic oil repellent of this embodiment, in the formula (1) or the formula (2), a perfluoroalkoxy group or fluorine atom represented by Rf ¹ , a divalent perfluoropolyether group represented by Rfo, and Rf ² The represented perfluoroalkylene group constitutes an oil repellency-imparting group.

  Moreover, in said formula (2), R is a coupling group which connects an oil-repellent imparting group and a hydrophilic imparting group in a molecular chain. The structure of the linking group R is not particularly limited as long as it is a linear or branched divalent organic group. The linking group R may or may not contain one or more types of bonds selected from ether bonds, ester bonds, amide bonds and urethane bonds in the molecular chain.

  Specifically, for example, the linking group R may be a hydrocarbon group having 1 to 20 carbon atoms, or may contain one or more selected from a polyoxyalkylene group and an epoxy group.

  Further, the linking group R may have a polymer of a binary copolymer or a terpolymer in the molecular chain.

  Here, in the above formula (2), an example in the case of having a terpolymer in the molecular chain of the linking group R is shown in the following general formula (3).

In the general formula (3), R ¹⁰ is a hydrogen atom or a methyl group. Further, o, p, and q are independent integers of 1 or more. X ₁ and X ₂ are different hydrophilic imparting groups. R ¹¹ is a divalent organic group that connects the main chain of the copolymer and the oil repellency-imparting group, and includes one or more bonds selected from an ether bond, an ester bond, an amide bond, and a urethane bond. . Furthermore, there may be R ¹² or R ¹³ which is a divalent organic group that connects the main chain of the copolymer and the hydrophilic imparting group, and it is selected from an ether bond, an ester bond, an amide bond, and a urethane bond. One or more types of bonds may or may not be included.

  In addition, it is preferable to select and introduce the linking group R as appropriate according to the properties desired to be imparted to the hydrophilic oil repellent. Specifically, for example, if you want to adjust the solubility in water or organic solvent, if you want to improve the durability by improving the adhesion between the surface coating material containing a hydrophilic oil repellent (coating agent) and the substrate, The case where it is desired to improve the compatibility between the hydrophilic oil repellent and the resin component or the coating component. The method includes adjusting the presence or type of polar groups that affect intermolecular interactions, adjusting the chain length of hydrocarbon groups in a linear or branched structure, and including in substrates, resin components, or paint components. For example, a structure similar to a part of the chemical structure is introduced.

Moreover, in said formula (1) or said formula (2), X is any one hydrophilicity imparting group selected from the group which consists of an anionic type, a cationic type, and an amphoteric type.
Hereinafter, the structure of the hydrophilic oil repellent according to the present embodiment will be described by dividing the hydrophilic imparting group X into cases.

(Anion type)
In the case where the hydrophilic imparting group X is an anionic type, the above X is “—CO ₂ M ¹ ” or “—SO ₃ M ¹ ” (M ¹ is an alkali metal, alkaline earth metal, Mg, Al, R ¹ R ² R ³ R ⁴ N ⁺ ; R ^{1 to} R ⁴ each have a hydrogen atom or an independent linear or branched alkyl group having 1 to 20 carbon atoms.

  Examples of the alkali metal include lithium (Li), sodium (Na), potassium (K), and cesium (Cs). Examples of the alkaline earth metal include calcium (Ca), strontium (Sr), and barium (Ba).

As the quaternary ammonium salt ^{(R 1 R 2 R 3 R} 4 N +), a straight-chain or branched alkyl group R 1 to R ⁴ is up to 1 to 20 carbon atoms which independently hydrogen atom or each If there is, it will not be specifically limited. More specifically, examples of the compound in which R ¹ R ² R ³ R ⁴ are all the same include, for example, (CH ₃ ) ₄ N ⁺ , (C ₂ H ₅ ) ₄ N ⁺ , (C ₃ H ₇ ) ₄ N ⁺ , (C ₄ H ₉ ) ₄ N ⁺ , (C ₅ H ₁₁ ) ₄ N ⁺ , (C ₆ H ₁₃ ) ₄ N ⁺ , (C ₇ H ₁₅ ) ₄ N ⁺ , (C ₈ H ₁₇ ) ₄ N ⁺ , (C ₉ H ₁₉ ) ₄ N ⁺ , (C ₁₀ H ₂₁ ) ₄ N ^{+ and the} like. In addition, when R ¹ R ² R ³ is all a methyl group, for example, R ⁴ is (C ₂ H ₅ ), (C ₆ H ₁₃ ), (C ₈ H ₁₇ ), (C ₉ H ₁₉ ), Examples of the compound include (C ₁₀ H ₂₁ ), (C ₁₂ H ₂₅ ), (C ₁₄ H ₂₉ ), (C ₁₆ H ₃₃ ), and (C ₁₈ H ₃₇ ). Further, when all of R ¹ R ² are methyl groups, for example, all of R ³ R ⁴ are (C ₈ H ₁₇ ), (C ₁₀ H ₂₁ ), (C ₁₂ H ₂₅ ), (C ₁₄ H ₂₉ ). , (C ₁₆ H ₃₃ ), (C ₁₈ H ₃₇ ) and the like. Furthermore, examples of the case where R ¹ is a methyl group include compounds in which R ² R ³ R ⁴ are all (C ₄ H ₉ ), (C ₈ H ₁₇ ), and the like.

By the way, in applications such as oil-water separation filter media that are used in contact with water, it is desirable to have durability against water and durability of a hydrophilic oil-repellent effect. From the above viewpoint, the hydrophilic oil repellent of the present embodiment is desirably a hardly soluble compound having low solubility in water. That is, in the hydrophilic oil repellent of the present embodiment, when the hydrophilic imparting group X is an anion type, the M ^{1 as} a counter ion is preferably an alkaline earth metal, Mg, or Al, particularly Ca, Ba. Mg is preferred because of its excellent hydrophilic oil repellency and low solubility in water.

Here, when the hydrophilic imparting group X is an anionic type, specific examples of the structure of the hydrophilic oil repellent represented by the above formula (1) or the above formula (2) (however, the structure of M ¹ which is a counter ion is excluded) ) Include, for example, the structures of the following formulas (4) to (29).

(Cation type)
When the hydrophilic imparting group X is a cation type, the above X has “—N ⁺ R ⁵ R ⁶ R ⁷ • Cl ⁻ ”, “—N ⁺ R ⁵ R ⁶ R ⁷ • Br ⁻ ”, “— ^{N + R 5 R 6 R 7} · I - "" ^{- N + R 5 R 6 R} 7 · CH 3 SO 3 - , "" ^{- N + R 5 R 6 R} 7 · NO 3 - "," (- ^{N + R 5 R 6 R 7} ) 2 CO 3 2- "or" ^{(-N + R 5 R 6 R} 7) 2 SO 4 2- ^"(R 5 to R ⁷ is C 1 -C independent hydrogen atom or each Up to 20 linear or branched alkyl groups).

  Here, when the hydrophilic imparting group X is a cationic type, specific examples of the structure of the hydrophilic oil repellent represented by the above formula (1) or the above formula (2) include, for example, the following formulas (30) to (52): ) Structure.

(Bisexual)
In the case where the hydrophilic imparting group X is an amphoteric type, the above-mentioned X is at the end of the carboxybetaine type “—N ⁺ R ⁸ R ⁹ (CH ₂ ) _n CO ₂ ⁻ ”, and the sulfobetaine type “—N ⁺ R”. ⁸ R ⁹ (CH ₂ ) _n SO ₃ ⁻ ”or“ —N ⁺ R ⁸ R ⁹ O ⁻ ”of the amine oxide type (n is an integer of 1 to 5, R ⁸ and R ⁹ are a hydrogen atom or a carbon number of 1 to 10 alkyl groups).

  Here, when the hydrophilic imparting group X is an amphoteric type, specific examples of the structure of the hydrophilic oil repellent represented by the above formula (1) or the above formula (2) include, for example, the following formulas (53) to (67): ) Structure.

  In addition, the specific example of the structure of the hydrophilic oil repellent of this embodiment mentioned above is an example, Comprising: The technical scope of this invention is not limited to the said specific example. That is, the hydrophilic oil repellent agent of this embodiment has at least one oil repellent imparting group containing a perfluoropolyether group and one or more hydrophilic imparting groups of anionic type, cationic type or amphoteric type in the molecule. If you do.

  In addition, the above-described hydrophilic oil repellent of the present embodiment sufficiently exhibits the hydrophilic oil repellency, but the practical environment includes acids, alkalis, oils, etc. In this case, it is desirable to increase durability against the actual environment by appropriately combining hydrophilic oil repellents.

  In addition, the hydrophilic oil repellent of this invention can add a various change in the range which does not deviate from the meaning of this invention. For example, the hydrophilic oil repellent of the present embodiment may have two or more oil repellent imparting groups that are the same or different in the molecule. Further, when the molecule has two or more oil repellency-imparting groups, it may be provided at the end of the molecular chain or in the molecular chain.

  Moreover, the hydrophilic oil repellent of this embodiment may have 2 or more of the same or different hydrophilicity imparting groups in a molecule | numerator.

  Moreover, the hydrophilic oil repellent of this embodiment may have two or more same or different bonds in the linking group. Furthermore, when the linking group is a polymer type, the number of repeating units and the bonding order are not particularly limited.

  Next, a method for evaluating the hydrophilic oil repellency of the perfluoropolyether group-containing compound represented by the above formula (1) or the above formula (2) will be described. Here, the hydrophilic oil repellency can be specifically evaluated by a filter penetration test.

  In the filter penetration test, first, a perfluoropolyether group-containing compound represented by the above formula (1) or the above formula (2) is dissolved in methanol to obtain a 2.0 mass% methanol solution, and a commercially available PTFE product is used in the solution. A membrane filter (ADVANTEC T100A-: pore size 1 μm, porosity 79%, thickness 75 μm) is immersed, and water and n-hexadecane are dropped into the filter obtained by drying at room temperature. After dropping, the perfluoropolyether group-containing compound has hydrophilic oil repellency when water penetrates into the filter within 5 minutes and n-hexadecane does not penetrate into the filter after 30 minutes by visual judgment (i.e., The perfluoropolyether group-containing compound is a hydrophilic oil repellent). The untreated PTFE membrane filter did not penetrate water after 30 minutes, and n-hexadecane penetrated the filter within 5 minutes (that is, water-repellent and lipophilic).

In the filter penetration test, water and n-hexadecane are dropped using the following conditions.
Drop volume: 40-45 μL / drop (water)
Drop volume: 20-25 μL / drop (n-hexadecane)
Drop height: 5 cm from the surface of the PTFE membrane filter
Dripping jig: Poly dropper

  Moreover, you may use the measurement result of a contact angle for evaluation of hydrophilic oil repellency of the perfluoropolyether group containing compound shown by the said Formula (1) or the said Formula (2).

  In the contact angle measurement, first, the perfluoropolyether group-containing compound represented by the above formula (1) or the above formula (2) was dissolved in methanol to obtain a 2.0 mass% methanol solution. A soda glass plate which has been preliminarily immersed in a 1N aqueous potassium hydroxide solution at room temperature for 2 hours, then washed with pure water and acetone and then dried (dip coating) in the methanol solution, and methanol is removed by drying at room temperature. It removes and forms a coating film on the said glass plate. Next, water and n-hexadecane are dropped on this coating film, and the contact angles between the coating film and the droplets are measured.

In the contact angle measurement, water and n-hexadecane are dropped using the following conditions.
Drop volume: 2 μL / drop (water)
Drop volume: 2 μL / drop (n-hexadecane)

<Method for producing hydrophilic oil repellent>
Next, the manufacturing method of the hydrophilic oil repellent of this embodiment is demonstrated.
The hydrophilic oil repellent of the present embodiment can be produced using a carboxylic acid halide or sulfonic acid halide having a generally available perfluoropolyether group as a raw material.

  In addition, the manufacturing method of the hydrophilic oil repellent of this embodiment turns into a manufacturing method which changes with types of X shown in said Formula (1) and said Formula (2). In the following, description will be made for each case.

(In the case of anion type)
First, the case where the perfluoropolyether group containing compound shown to said Formula (1) is manufactured is demonstrated.
When a carboxylic acid halide having a perfluoropolyether group is used as a raw material, M (OH) _m in an aqueous solution (M is Li, Na, K, Ca, Mg, Al, etc., m is Li, Na, K, etc.) 1 in the case of monovalent cations, 2 in the case of divalent cations such as Ca and Mg, 3) in the case of trivalent cations such as Al, and in the case of using a sulfonic acid halide having a perfluoropolyether group as an aqueous solution M (OH) _m (M is Li, Na, K, R ¹ R ² R ³ R ⁴ N ⁺ , Ca, Mg, Al, etc., m is 1 in the case of a monovalent cation such as Li, Na, K, etc. 2 in the case of a divalent cation such as Ca, Mg, 3 in the case of a trivalent cation such as Al, R ^{1 to} R ⁴ are hydrogen atoms or linear or branched alkyl groups having 1 to 20 carbon atoms, which are independent of each other. ) To each of them to neutralize The target product is extracted from the solid obtained by drying using a solvent in which the target product is soluble and the by-product halide is insoluble, and the extraction solvent is further solidified. The object can be obtained. If necessary, this salt can be converted to carboxylic acid or sulfonic acid using an acid such as sulfuric acid, and after distillation, the salt can be purified again with M (OH) _m to obtain a high purity. is there.

Next, the case where the perfluoropolyether group-containing compound represented by the above formula (2) is produced will be described.
Specifically, for example, when a linking group R having an amide bond is introduced between an oil repellency-imparting group (perfluoroalkylene group represented by Rf ² ) and an anionic hydrophilic imparting group, first, perfluoropolyether Alkali metal of carboxylic acid or sulfonic acid having amide bond by reacting group-containing carbonyl fluoride or sulfonyl fluoride with aminoalkyl carboxylic acid or aminophenyl sulfonic acid and then reacting with alkali hydroxide A salt is obtained.

For example, when a linking group R having an ester bond is introduced between an oil repellency-imparting group (perfluoroalkylene group represented by Rf ² ) and an anionic hydrophilic imparting group, first, a perfluoropolyether group-containing carbonyl An alkali metal salt of a carboxylic acid or sulfonic acid having an ester bond is obtained by reacting fluoride or sulfonyl fluoride with a hydroxyphenyl organic acid and then reacting with an alkali hydroxide.

For example, when a linking group R having an ether bond is introduced between an oil repellency-imparting group (perfluoroalkylene group represented by Rf ² ) and an anionic hydrophilic imparting group, first, a perfluoropolyether group-containing carbonyl Fluoride is reduced with lithium aluminum hydride (LiAlH ₄ ) or sodium borohydride (NaBH ₄ ) to produce an alcohol having a perfluoropolyether group. Next, after converting to potassium alcoholate with t-butoxy potassium or the like and reacting with a metal salt of a halogenated organic acid, an alkali metal salt of a carboxylic acid having an ether bond is obtained.

(Cation type)
Specifically, for example, among raw materials, perfluoropolyether group-containing carbonyl fluoride or sulfonyl fluoride and N, N-dialkylaminoalkyleneamine are amide-bonded to form a terminal tertiary amine, followed by iodination. It has a cationic hydrophilic imparting group by quaternization with an alkylating agent such as methyl (CH ₃ I), methyl bromide (CH ₃ Br), or dimethyl sulfate ((CH ₃ ) ₂ SO ₄ ). A perfluoropolyether group-containing compound is obtained.

For example, among the raw materials, perfluoropolyether group-containing carbonyl fluoride or sulfonyl fluoride and N, N-dialkylaminoalkylene alcohol are ether-bonded to form a terminal tertiary amine, and then methyl iodide (CH ₃ I), perfluoropolyether having a cationic hydrophilic imparting group by quaternization with an alkylating agent such as methyl bromide (CH ₃ Br) or dimethyl sulfate ((CH ₃ ) ₂ SO ₄ ) A group-containing compound is obtained.

(In the case of bisexual type)
Specifically, for example, in the case of the carboxybetaine type, first, among the raw materials, a perfluoropolyether group-containing carbonyl fluoride or sulfonyl fluoride and an N, N-dialkylaminoalkyleneamine are amide-bonded, or A perfluoropolyether group-containing compound having an amphoteric hydrophilic imparting group is obtained by ether-bonding with N, N-dialkylaminoalkylene alcohol to form a terminal tertiary amine and then reacting with sodium monochloroacetate. .

  Also, for example, in the case of sulfobetaine type, after forming a terminal tertiary amine as described above, it is reacted with a cyclic sulfonic acid ester compound typified by 1,3-propane sultone, etc. A perfluoropolyether group-containing compound having an imparting group is obtained.

  Further, for example, in the case of an amine oxide type, a perfluoropolyether group-containing compound having an amphoteric hydrophilic imparting group can be obtained by reacting with hydrogen peroxide after being converted to a terminal tertiary amine as described above. .

<Surface coating material>
By incorporating the above-described hydrophilic oil repellent of this embodiment into water or an organic solvent, a surface covering material of the hydrophilic oil repellent can be formed. Here, as an organic solvent, methanol, ethanol, IPA, tetrahydrofuran, hexane, chloroform, toluene, ethyl acetate, DMSO, DMF, acetone, a fluorine-type solvent etc. are mentioned, for example. In particular, water, alcohols such as methanol, ethanol, and IPA, or a mixture of water and alcohol are preferable from the viewpoint of easy drying and use, and environmental impact.

  Here, in the surface coating material, the mass composition ratio of the hydrophilic oil repellent and water or the organic solvent is preferably 0.2 to 99.8 to 50 to 50, and more preferably 1 to 99 to 20 to 80. If the mass composition ratio of the hydrophilic oil repellent in the surface coating material is less than 0.2, the entire substrate may not be sufficiently hydrophilic and oil repellent when processed, which is not preferable. On the other hand, if the mass composition ratio of the hydrophilic oil repellent in the surface coating material exceeds 50, the solution dispersion stability of the surface coating material is likely to be impaired, which is not preferable. In consideration of applicability and durability of the product, 1:99 to 20:80 is preferable.

  In addition to improving adhesion to the base material, the surface coating material has a function of wrapping a hydrophilic oil repellent and reducing the area in contact with the environment of the hydrophilic oil repellent itself. In order to improve this, it is preferable to add a binder as an optional component.

  Specific examples of the binder include resin and inorganic glass. Examples of the resin include a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, a UV curable resin, and more specifically, for example, polyvinyl chloride resin, polyethylene resin, polypropylene resin, polycarbonate resin, polyester resin, polystyrene. Resins, silicone resins, polyvinyl acetal resins, polyvinyl alcohol resins, acrylic polyol resins, polyester polyol resins, urethane resins, fluororesins, thermoplastic acrylic resins and other thermoplastic resins, epoxy resins, phenol resins and thermosetting acrylics Examples thereof include thermosetting resins such as resins.

  Furthermore, in order to maximize the hydrophilic oil repellency, it is preferable to use a hydrophilic polymer as a binder. Moreover, as a hydrophilic polymer, what contains a hydroxyl group is preferable.

  Specific examples of the hydrophilic polymer include polysaccharides such as polyvinyl alcohol, polyvinyl butyral, and cellulose, and derivatives thereof. These may be used alone or in combination of two or more. The hydrophilic polymer may be crosslinked with a crosslinking agent. Such cross-linking improves the durability of the coating film (film).

  The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose. Specific examples include an epoxy compound, an isocyanate compound, an aldehyde compound, an ultraviolet crosslinking compound, a leaving group-containing compound, a carboxylic acid compound, and a urea compound.

Specifically, as the inorganic glass, for example, trialkoxysilane represented by the chemical formula [R ¹⁴ Si (OR ¹⁵ ) ₃ ], chemical formula [Si (OR ¹⁶ ) ₄ ] (R ^{14 to} R ¹⁶ are independent carbons, respectively. And silane compounds such as tetraalkoxysilane, water glass, and the like. Among these, water glass is preferable because the effect of improving durability is high.

  In the surface coating material, the mass composition ratio of the hydrophilic oil repellent and the binder is preferably in the range of 10:90 to 99.9: 0.1. If the mass composition ratio of the hydrophilic oil repellent is less than 10, it is not preferable because hydrophilic oil repellency cannot be obtained sufficiently.

  As a mixing method for forming the surface coating material, a hydrophilic oil repellent such as a ball mill, a roll mill, a sand mill, a paint shaker, a homogenizer, an impeller stirrer, an ultrasonic disperser, a magnetic stirrer or the like is dispersed in water or an organic solvent. The method is not particularly limited as long as it can be dissolved.

  In addition to the hydrophilic oil repellent, the solvent, and the binder, the surface coating material may further contain an additive as an optional component in order to impart functions other than the hydrophilic oil repellent such as a pigment, a conductivity imparting agent, and a leveling agent. Good.

<Coating film>
A coating film can be formed by coating the substrate with the surface coating material described above. In this coating film, there are a case where it consists only of a hydrophilic oil repellent agent and a case where it contains a binder. When a binder is included, the mass composition ratio between the hydrophilic oil repellent and the binder is preferably in the range of 10:90 to 99.9: 0.1. Here, if the mass composition ratio of the hydrophilic oil repellent is less than 10, it is not preferable because sufficient hydrophilic oil repellency cannot be obtained. Considering adhesion to the substrate and durability of the coating film, 10 to 90 to 90 to 10 is particularly preferable.

  Specifically, for example, the coating film is formed on the surface of the base material by applying the surface coating material described above to the surface of the base material and drying to remove the solvent. can do.

  The substrate is not particularly limited, but glass, plastic, metal, ceramics, stainless steel, aluminum, wood, stone, cement, concrete, fiber, fabric, paper, leather, combinations thereof, structures, laminates, and the like. Can be used.

  In the coating step, the coating method on the surface of the substrate is not particularly limited. Specifically, for example, a dipping method in which the substrate is immersed in the surface coating material, a method using an application means such as a spray, a brush, or a roller, or a method using a printing method may be used.

  In the formation process, the conditions for the drying treatment of the coating film vary depending on the type and content of the solvent contained in the surface coating material, but for example, drying at room temperature for 1 to 24 hours or affecting the substrate. Drying by heating to a certain extent is mentioned.

<Resin composition>
The hydrophilic oil repellent of this embodiment mentioned above can be used as an additive for imparting a hydrophilic oil repellent function to various resins.

  Examples of the resin include a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, and a UV curable resin. The resin is not particularly limited as long as it can disperse or dissolve the hydrophilic oil repellent. Specifically, as such a resin, for example, polyvinyl chloride resin, polyethylene resin, polypropylene resin, polycarbonate resin, polyester resin, polystyrene resin, silicone resin, polyvinyl acetal resin, polyvinyl alcohol resin, acrylic polyol resin, Examples thereof include thermoplastic resins such as polyester polyol resin, urethane resin, fluororesin, and thermoplastic acrylic resin, and thermosetting resins such as epoxy resin, phenol resin, and thermosetting acrylic resin.

  Furthermore, in order to maximize the hydrophilic oil repellency, it is preferable to use a hydrophilic polymer as the resin. As the hydrophilic polymer, those containing a hydroxyl group are preferred. Specific examples include polysaccharides such as polyvinyl alcohol, polyvinyl butyral, cellulose, and derivatives thereof. These may be used alone or in combination of two or more. The hydrophilic polymer may be crosslinked with a crosslinking agent. Such cross-linking improves the durability of the coating film (film).

  The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose. Specific examples include an epoxy compound, an isocyanate compound, an aldehyde compound, an ultraviolet crosslinking compound, a leaving group-containing compound, a carboxylic acid compound, and a urea compound.

  In addition to hydrophilic oil repellents and resins, the resin composition contains additives for imparting functions other than hydrophilic oil repellents such as fluidity improvers, surfactants, flame retardants, conductivity-imparting agents and fungicides. It may further be included as an optional component.

  The method for forming the resin composition is not particularly limited as long as it is a method capable of dispersing or dissolving a hydrophilic oil repellent appropriately selected according to the type of resin. Specifically, for example, as a method for mixing the hydrophilic oil repellent with the thermoplastic resin, there is a method of mixing by kneading by an extrusion method or a roll method.

  The resin composition can be further processed into a molded resin molded product. Specific examples include injection molded products such as films, sheets, threads, and housings.

  In the resin composition, the mass composition ratio of the hydrophilic oil repellent and the resin is preferably in the range of 10:90 to 99.9: 0.1. If the mass composition ratio of the hydrophilic oil repellent is less than 10, it is not preferable because the hydrophilic oil repellent function cannot be sufficiently exhibited. On the other hand, if the mass composition ratio of the hydrophilic oil repellent exceeds 99.9, it is not preferable because the physical properties of the resin are impaired and it is difficult to maintain the moldability.

  Applications of the coating film and the resin composition described above include application to a member that is expected to be quick-drying such as water, a member that is expected to have an antifouling effect, a member that is expected to have an antifogging effect, and oil removability. Can be mentioned.

  More specific applications where quick drying of water and the like are expected include building materials, building exteriors such as outer walls and roofs, building interiors, window frames, window glass, automobiles, rail vehicles, aircraft, ships, bicycles, motorcycles Exterior and painting of vehicles such as, machinery and equipment exteriors, dust covers and coatings, signs, traffic signs, various display devices, advertising towers, road noise barriers, railway noise barriers, bridges, guard rail exteriors and coatings , Tunnel interior and painting, insulators, solar cell covers, solar water heater heat collection covers, heat exchanger radiating fins, plastic houses, vehicle lighting cover, housing equipment, toilets, bathtubs, washstands, lighting fixtures, lighting covers , Kitchen utensils, tableware, dishwashers, tableware dryers, sinks, cooking ranges, kitchen hoods, ventilation fans, and films for attaching to the surface of the article.

  More specific applications where antifouling effects are expected include building exteriors such as exterior walls and roofs, building interiors, window frames, window glass, signs, traffic signs, noise barriers, automobiles, rail cars, Exteriors and paintings of vehicles such as aircraft, ships, bicycles and motorcycles, exteriors of machinery and equipment, dustproof covers and coatings, various display devices, advertising towers, soundproof walls for roads, soundproof walls for railways, bridges, guardrails And painting, tunnel interior and painting, insulator, solar battery cover, solar water heater heat collection cover, plastic house, vehicle lighting cover, housing equipment, toilet bowl, bathtub, wash basin, lighting fixture, lighting cover, kitchenware, Tableware, dishwasher, dish dryer, sink, cooking range, kitchen hood, ventilation fan, etc. Examples of the optical member include a cover glass or a cover sheet of a touch panel, an icon sheet, a screen protection film, and an optical disk. In particular, it has excellent characteristics in terms of removability against oil contamination in canteens and kitchenware. Furthermore, the film etc. for making it stick on the surface of these articles | goods are mentioned. It can also be applied to snow country roofing materials, antennas, power transmission lines, etc., and in that case, characteristics excellent in snow accretion prevention can be obtained.

  More specific applications where anti-fogging effects are expected include glass for automobiles and building materials, rear mirrors for vehicles, mirrors for bathrooms, mirrors for toilets, mirrors such as road mirrors, eyeglass lenses, optical lenses, Examples include photographic lenses and films for attaching to the surfaces of these articles.

<Oil-water separation filter media>
When a mixed liquid of water and oil is passed through a filter paper, nonwoven fabric, cartridge filter, inorganic or organic porous material or porous membrane treated with the surface coating material described above, water passes through the filter, etc. On the other hand, since oil cannot pass through, it can be used as a hydrophilic oil-repellent separation membrane or filter that can separate oil and water only by gravity (collectively referred to as “separation filter medium”). This separation membrane and filter can be used, for example, as an oil-water separation membrane or an oil-water separation filter (that is, “oil-water separation filter medium”) for separating water and oil during oil extraction or recovery of spilled oil. is there.

  Moreover, since the oil-water separation filter medium described above is imparted with hydrophilic oil repellency, it is difficult for organic molecules and soil mud contaminated with oil to adhere, and excellent fouling resistance is obtained. Further, dirt attached by physical treatment such as back pressure cleaning is easily removed, and easy cleaning is excellent.

<Porous body>
When the hydrophilic oil repellent of this embodiment is used in the form of a porous body, it is preferable because more excellent oil / water separation performance can be obtained.

  As a method for obtaining a porous body, a generally known method can be applied. Specifically, for example, there is a method of drying a solution or dispersion of a hydrophilic oil repellent by a spray drying method. The particles thus obtained are particularly preferable because the particle diameter can be controlled together with the formation of the porous body, and the particles can be applied as they are as a filtering material.

  In addition, when producing porous particles, the physical strength of the porous body is obtained by bonding the porous particles by adding a binder such as resin or glass to the solution or dispersion of the hydrophilic oil repellent. It is possible to increase or to reduce the solubility in water.

  As the resin, the above-described thermoplastic resin or thermosetting resin can be used, and as the vitreous, the above-mentioned silane compound or water glass can be used. It is not limited, and the particles may be added as appropriate within the boundable range. Typically, it is preferable to use a mass composition ratio of the hydrophilic oil repellent and the binder in the range of 10:90 to 99.9: 0.1.

  It is also possible to carry the hydrophilic oil repellent of the present invention on another porous body. As the porous material to be supported, clay minerals such as silica, alumina, zeolite, calcium carbonate, talc and montmorillonite can be used. As a supporting method, a method of adding a porous material to be supported to a solution or dispersion of a hydrophilic oil repellent and removing the solvent by drying can be applied. As the carrying ratio, the mass composition ratio between the hydrophilic oil repellent and the porous body to be carried is selected from the range of 1:99 to 50:50 in terms of hydrophilic oil repellency characteristics.

  The obtained porous particles are more preferable because a superior oil / water separation performance can be obtained by fixing to the surface of a substrate such as a filter paper, a nonwoven fabric, or a cartridge filter. In addition, the above-described resin or glass can be used for fixing to the base material.

  As described above, the hydrophilic oil repellent of the present embodiment is a compound containing an oil repellency-imparting group containing a perfluoropolyether group in the molecule and any one of anionic, cationic and amphoteric hydrophilic imparting groups. Since it is a material having excellent hydrophilic oil repellency, it can be applied to a wide variety of uses.

  Moreover, since the hydrophilic oil repellent of this embodiment uses the carboxylic acid halide or sulfonic acid halide which has a perfluoroalkyl group as a raw material, it can synthesize | combine various derivatives easily.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  Hereinafter, the effects of the present invention will be described in more detail by way of examples. In addition, this invention is not limited at all by the Example.

(Synthesis Example 1)
"Synthesis of perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) potassium"
1. Perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoyl) fluoride in a mixed solution of 2.7 g of 5% aqueous potassium hydroxide and 1.0 g of methanol 5 g (Wako Pure Chemical Industries) was added dropwise to carry out the reaction. After water was distilled off from the reaction solution, it was redispersed in methanol, and insoluble matter was separated by filtration. Methanol was distilled off from the filtrate, and 1.4 g of potassium perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) was obtained as a residue.

(Synthesis Example 2)
"Synthesis of perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) calcium"
0.1 g of calcium hydroxide was added to a mixed solution of 4 g of water and 1.5 g of methanol, and then perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoyl) fluoride. 1.5g was dripped and reaction was performed. After water was distilled off from the reaction solution, it was redispersed in methanol, and insoluble matter was separated by filtration. Methanol was distilled off from the filtrate, and 1.3 g of perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) calcium was obtained as a residue.

(Synthesis Example 3)
“Synthesis of potassium perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoate)”
Perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoyl) fluoride 1.3 g (Wako Pure Chemical Industries, Ltd.) in a mixed solution of 3.7 g of 5% aqueous potassium hydroxide and 1.5 g of methanol ) Was added dropwise to carry out the reaction. After water was distilled off from the reaction solution, it was redispersed in methanol, and insoluble matter was separated by filtration. Methanol was distilled off from the filtrate, and 1.3 g of potassium perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoate) was obtained as a residue.

(Synthesis Example 4)
"Synthesis of perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoic acid) calcium"
To a mixed solution of 3.4 g of water and 1.4 g of methanol, 0.1 g of calcium hydroxide was added, and then 1.2 g of perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoyl) fluoride ( Wako Pure Chemical Industries) was added dropwise to carry out the reaction. After water was distilled off from the reaction solution, it was redispersed in methanol, and insoluble matter was separated by filtration. Methanol was distilled off from the filtrate, and 1.0 g of perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoic acid) calcium was obtained as a residue.

<Production of surface coating material>
Example 1
2% by mass of potassium perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) obtained in Synthesis Example 1 and 98% by mass of methanol as a solvent were added. The dissolved solution was used as the surface coating material of Example 1.

(Example 2)
2% by mass of perfluoro (2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid) calcium obtained in Synthesis Example 2 and 98% by mass of methanol as a solvent were added. The dissolved solution was used as the surface coating material of Example 2.

(Example 3)
Perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoic acid obtained in Synthesis Example 3 was added to a mixed solvent consisting of 40% by mass of hexafluoro-m-xylene and 60% by mass of ethanol. ) A solution containing 1% by mass of a hydrophilic oil repellent agent dissolved in potassium was used as the surface treatment material of Example 3.

Example 4
Perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoic acid obtained in Synthesis Example 4 was added to a mixed solvent composed of 40% by mass of hexafluoro-m-xylene and 60% by mass of ethanol. A solution containing 1% by mass of a hydrophilic oil repellent agent dissolved in calcium was used as the surface treatment material of Example 4.

(Comparative Example 1)
A solution obtained by adding 98% by mass of methanol as a solvent to 2% by mass of commercially available calcium perfluoroheptanoate was used as the surface coating material of Comparative Example 1.

(Comparative Example 2)
A solution obtained by adding 98% by mass of methanol as a solvent to 2% by mass of commercially available potassium perfluorobutanesulfonate was used as the surface coating material of Comparative Example 2.

<Evaluation by filter penetration test>
A filter penetration test was conducted on the coating films obtained from the surface coating materials of the examples and comparative examples.
Specifically, first, a commercially available PTFE membrane filter (ADVANTEC T100A-: pore diameter 1 μm, porosity 79%, thickness 75 μm) was dipped on the surface coating materials of Examples 1-4 and Comparative Examples 1-2. After the filter was sufficiently impregnated with the solution, it was lifted and methanol was removed by natural drying.

Next, water and n-hexadecane were respectively added dropwise to the test PTFE membrane filter prepared, and the permeability was visually determined based on the following definitions to evaluate hydrophilic oil repellency. The results are shown in Table 1 below.
In addition, the following conditions were used as a dripping method of water and n-hexadecane.
Drop volume: (40-45) μL / drop (water)
Drop volume: (20-25) μL / drop (n-hexadecane)
Drop height: 5 cm from the surface of the filter
Dripping jig: Poly dropper

Moreover, in the filter penetration test of the following Table 2, the definition of an evaluation result is as follows.
Immediately permeate: Infiltrate within 30 seconds after dropping a droplet on PTFE membrane filter Gradually permeate: Infiltrate within 30 seconds to less than 5 minutes after dropping a droplet Not permeate: After dropping a droplet, What does not penetrate for 30 minutes

  As shown in Table 1, the results of the filter penetration tests in Examples 1 to 4 indicate that the water penetration result is “immediately penetrated” and the n-hexadecane penetration result is “not penetrated”. It was confirmed that.

  On the other hand, as a result of the filter penetration test in Comparative Examples 1 and 2, the water penetration result is “does not penetrate” and the penetration result of n-hexadecane is “gradual penetration”. It was confirmed that.

  Since the hydrophilic oil-repellent agent, dispersion liquid and solution thereof of the present invention can impart hydrophilic oil repellency, they can be applied to a coating film having an antifouling function, an oil-water separation filter medium, and the like.

Claims (20)

A hydrophilic oil repellent which is a perfluoropolyether group-containing compound represented by the following general formula (1).
Rf ¹ -Rfo-Rf ² -X (1)
In the general formula (1), Rf ¹ is a C 1-6 perfluoroalkoxy group or a fluorine atom. Rfo is a divalent perfluoropolyether group. Further, Rf ² is a 1 to 20 carbon atoms, a linear or branched perfluoroalkyl group.
X is any one hydrophilicity-imparting group selected from the group consisting of anionic, cationic and amphoteric types. A hydrophilic oil repellent which is a perfluoropolyether group-containing compound represented by the following formula (2).
^{Rf 1 -Rfo-Rf 2 -R-} X ··· (2)
In the general formula (2), Rf ¹ is a C 1-6 perfluoroalkoxy group or a fluorine atom. Rfo is a divalent perfluoropolyether group. Further, Rf ² is a 1 to 20 carbon atoms, straight-chain or branched perfluoroalkyl group.
R is a divalent organic group and is a linear or branched linking group.
X is any one hydrophilicity-imparting group selected from the group consisting of anionic, cationic and amphoteric types.   The hydrophilic oil-repellent agent according to claim 2, wherein the R includes one or more bonds selected from an ether bond, an ester bond, an amide bond, and a urethane bond in a molecular chain.   4. The composition according to claim 1, comprising two or more perfluoropolyether group-containing compounds selected from the group consisting of the perfluoropolyether group-containing compounds represented by the formula (1) and the formula (2). 5. Hydrophilic oil repellent. X in the above formula (1) or the above formula (2) has “—CO ₂ M ¹ ” or “—SO ₃ M ¹ ”, “—OSO ₂ M ¹ ”, “—OP (OH) O _{2 at the terminal.} M ¹ ”,“ —OPO ₃ M ¹ ₂ ”or“ ═O ₂ PO ₂ M ¹ ”(M ¹ is an alkali metal, an alkaline earth metal, Mg, Al, R ¹ R ² R ³ R ⁴ N ⁺ ; R ^{1 to} R ⁴ are each an anionic hydrophilic group having a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms, each independently. The hydrophilic oil repellent agent described in 1. X in the above formula (1) or the above formula (2) has “—N ⁺ R ⁵ R ⁶ R ⁷ • Cl ⁻ ”, “—N ⁺ R ⁵ R ⁶ R ⁷ • Br ⁻ ”, “— ^{N + R 5 R 6 R 7} · I - "" ^{- N + R 5 R 6 R} 7 · CH 3 SO 3 - , "" ^{- N + R 5 R 6 R} 7 · NO 3 - "," (- ^{N + R 5 R 6 R 7} ) 2 CO 3 2- "or" ^{(-N + R 5 R 6 R} 7) 2 SO 4 2- ^"(R 5 to R ⁷ is C 1 -C independent hydrogen atom or each The hydrophilic oil-repellent agent according to any one of claims 1 to 4, which is a cationic hydrophilic imparting group having up to -20 linear or branched alkyl groups. X in the formula (1) or the formula (2) has carboxybetaine type “—N ⁺ R ⁸ R ⁹ (CH ₂ ) _n CO ₂ ^— ” or sulfobetaine type “—N ⁺ R” at the terminal. ⁸ R ⁹ (CH ₂ ) _n SO ₃ ⁻ ”or“ —N ⁺ R ⁸ R ⁹ O ⁻ ”of the amine oxide type (n is an integer of 1 to 5, R ⁸ and R ⁹ are a hydrogen atom or a carbon number of 1 to The hydrophilic oil-repellent agent according to any one of claims 1 to 4, which is an amphoteric hydrophilic imparting group having 10 alkyl groups). Including the hydrophilic oil repellent according to any one of claims 1 to 4 and a solvent,
The surface coating material whose mass composition ratio of the said hydrophilic oil repellent and the said solvent is the range of 0.2: 99.8-50: 50.   The surface covering material according to claim 8, wherein the solvent is water, alcohol, or a mixture of water and alcohol. Further including a binder,
The surface covering material according to claim 8 or 9 whose mass composition ratio of said hydrophilic oil repellent and said binder is the range of 10: 90-99.9: 0.1.   The surface covering material according to any one of claims 8 to 10, wherein the binder is a resin.   The surface covering material according to any one of claims 8 to 10, wherein the binder is a water-soluble resin.   The surface covering material according to any one of claims 8 to 10, wherein the binder is water glass.   The coating film containing the hydrophilic oil repellent as described in any one of Claims 1 thru | or 4. Further including a binder,
The coating film of Claim 14 whose mass composition ratio of the said hydrophilic oil repellent and the said binder is the range of 10: 90-99.9: 0.1. A hydrophilic oil repellent agent according to any one of claims 1 to 4 and a resin,
The resin composition whose mass composition ratio of the said hydrophilic oil repellent and the said resin is the range of 10: 90-99.9: 0.1.   An oil-water separation filter medium comprising the coating film according to claim 14 or 15 or the resin composition according to claim 16.   The porous body containing the hydrophilic oil repellent as described in any one of Claims 1 thru | or 4.   A porous body in which the hydrophilic oil repellent according to claim 1 is bound with a resin.   The porous body with which the hydrophilic oil repellent as described in any one of Claims 1 thru | or 4 is couple | bonded by vitreous.