Emulsion and method for producing same

Abstract

Provided is an emulsion which contains (A) a perfluoropolyether oil represented by formula (I), (B) a perfluoropolyether carboxylate represented by formula (II), (C) a water-soluble organic solvent, and (D) water. This emulsion has a mass average value of water / octanol partition coefficient (log P) within the range of -0.33 to 0. (In formula (I), Rf, Rf', p, q, and r are as defined in the description.) (In formula (II), Rf", X, Y, and n are as defined in the description.)

Description

Emulsion and method for producing the same

[0001] This invention relates to emulsions and methods for producing them.

[0002] High molecular weight perfluoropolyether compounds (e.g., those with a weight-average molecular weight of 2000 or more) generally dissolve in fluorinated solvents but have very low solubility in water and other organic solvents. Therefore, it is customary to use fluorinated solvents when preparing compositions containing perfluoropolyether compounds. However, fluorinated solvents are expensive and have an environmental impact, leading to a demand for aqueous compositions.

[0003] Techniques for preparing emulsions containing perfluoropolyether oil are known, as described in Patent Documents 1 and 2, among others.

[0004] International Publication No. 1995 / 18194, Japanese Patent Publication No. 2020-158600

[0005] However, the methods described in Patent Documents 1 and 2 both require an ultrasonic homogenizer or a high-pressure homogenizer, and are not particularly convenient. The object of the present invention is to provide a perfluoropolyether oil emulsion that can be prepared by a simple method.

[0006] In order to solve the above problems, the inventors conducted extensive research and found that a perfluoropolyether oil emulsion can be easily prepared using perfluoropolyether oil, a perfluoropolyether carboxylate, an aqueous organic solvent with a specific mass average value of the water / octanol partition coefficient, and water.

[0007] This invention was completed based on these findings and includes the following broad embodiments of the invention.

[0008] [Item 1] An emulsion comprising (A) a perfluoropolyether oil represented by the following formula (I), (B) a perfluoropolyether carboxylate salt represented by the following formula (II), (C) a water-soluble organic solvent, and (D) water, wherein the mass average value of the water / octanol partition coefficient (logP) of the water-soluble organic solvent (C) is in the range of -0.33 to 0.

[0009]

[0010] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p, q, and r are each independent integers of 0 or more, and p + q + r = 3 to 120. C) ３ F ６ O group, C ２ F ４ O group, and CF ２ The oxygen groups may be attached in any order.

[0011]

[0012] (In the formula, Rf'' is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a single bond or a divalent group having 1 to 10 carbon atoms. n is 7 to 20. M is an alkali metal, an ammonium base, or an organic amine base.) [Clause 2] The emulsion according to Claim 1, wherein the weight-average molecular weight of the perfluoropolyether oil (A) is in the range of 1,000 to 20,000. [Clause 3] The emulsion according to Claim 1 or 2, wherein the weight-average molecular weight of the perfluoropolyether carboxylate (B) is in the range of 1,800 to 3,000. [Clause 4] The emulsion according to any one of Claims 1 to 3, wherein the content of the perfluoropolyether carboxylate (B) is 1 to 20 parts by mass per 100 parts by mass of the perfluoropolyether oil (A). [Clause 5] [Item 6] An emulsion according to any one of items 1 to 4, wherein the content of the water-soluble organic solvent (C) is 5 to 100 parts by mass per 100 parts by mass of the perfluoropolyether oil (A). [Item 7] A lubricant comprising the emulsion according to any one of items 1 to 5. [Item 8] A method for producing the emulsion according to any one of items 1 to 5, comprising the steps of preparing a dispersion containing the perfluoropolyether oil (A), the perfluoropolyether carboxylate (B), and the water-soluble organic solvent (C), and mixing the dispersion with water (D).

[0013] According to the present invention, an emulsion of perfluoropolyethercarbon oil that can be prepared by a simple method can be provided.

[0014] In this specification, the singular form (a, an, the, etc.) includes both singular and plural forms unless otherwise explicitly stated or the context clearly contradicts it.

[0015] In this specification, "comprise" is a concept that also encompasses "consist essentially of" and "consist of."

[0016] <Emulsion> The emulsion according to the present invention contains the following (A) to (D). (A) A perfluoropolyether oil represented by the following formula (I).

[0017]

[0018] (In the formula, Rf and Rf' are the same or different and are perfluoroalkyl groups having 1 to 3 carbon atoms. p, q, and r are each independently an integer of 0 or more, and p + q + r = 3 to 120. C ３ F ６ O group, C ２ F ４ O group, and CF ２ O groups may be bonded in any order.) (B) A perfluoropolyether carboxylate represented by the following formula (II).

[0019]

[0020] (In the formula, Rf” is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a single bond or a divalent group having 1 to 10 carbon atoms. n is 7 to 20. M is an alkali metal, an ammonium base or an organic amine base.) (C) A water-soluble organic solvent having a mass average value of the water / octanol partition coefficient (logP) in the range of -0.33 to 0. (D) Water.

[0021] Hereinafter, each component will be described in detail. (A) The perfluoropolyether oil represented by formula (I).

[0022]

[0023] Rf and Rf' are the same or different and are perfluoroalkyl groups having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group having 1 to 3 carbon atoms include a trifluoromethyl group, a perfluoroethyl group, a perfluoro-n-propyl group, a perfluoroisopropyl group, and the like.

[0024] p, q, and r are each independently an integer of 0 or more, and p + q + r = 3 to 120. It is preferable that p + q + r is 5 to 100, and more preferably 10 to 80.

[0025] C ３ F ６ O group, C ２ F ４ O group, and CF ２ The oxygen groups may be attached in any order. Here, "C ３ F ６ O group, C ２ F ４ O group, and CF ２ "O groups are bonded in any order" means that the main chain of perfluoropolyether oil (A) is C ３ F ６ O group one or more repeating units and C ２ F ４ O group one or more repeating units and CF ２ It is a configuration in which one or more repeating units of O are randomly arranged, C ３ F ６ The number of repeating units of O and C ２ F ４ Number of O-group repeating units and CF ２ This means there is no regularity in the arrangement of the number of repeating units of O in the direction of the main chain. Also, C in formula (I) ３ F ６ The base is CF ２ CF ２ CF ２ It may also be a base, CF(CF ３ )CF ２ It may also be a base, CF ２ CF (CF ３ ) It may also be a base. C in equation (I) ２ F ４ The base is CF ２ CF ２ Even if it is the base, CF (CF ３ ) It may also be a base.

[0026] Examples of such perfluoropolyether oils include those having structures represented by the following general formulas (Ia) to (Id).

[0027]

[0028] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p is 3 to 120.)

[0029]

[0030] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p + r = 3 to 120. CF(CF) ３ ) CF ２ O group and CF ２ The oxygen groups may be attached in any order.

[0031]

[0032] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. q + r = 3 to 120. CF) ２ CF ２ O group and CF ２ The oxygen groups may be attached in any order.

[0033]

[0034] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p is 3 to 120.) In formula (Ia), p is 3 to 120, preferably 5 to 100, more preferably 10 to 80, and particularly preferably 15 to 50.

[0035] In formula (Ib), p:r is preferably in the range of 10:90 to 90:10. p+r is 3 to 120, preferably 5 to 100, and more preferably 10 to 80.

[0036] In formula (Ic), q:r is preferably in the range of 10:90 to 90:10. q+r is 3 to 120, preferably 5 to 100, and more preferably 10 to 80.

[0037] In formula (Id), p is 3 to 120, preferably 20 to 100, and more preferably 40 to 80.

[0038] Examples of commercially available perfluoropolyether oils include the Krytox series (manufactured by DuPont), Fomblin Y series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), Fomblin M series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), Fomblin W series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), Fomblin Z series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), Demnam S series (manufactured by Daikin Industries, Ltd.), and RecaloFlosso PT series (manufactured by Nikka Chemical Co., Ltd.).

[0039] The weight-average molecular weight of the perfluoropolyether oil is preferably 1,000 to 20,000, more preferably 1,500 to 15,000, and particularly preferably 2,000 to 10,000. The weight-average molecular weight can be measured by conventionally known methods such as gel filtration chromatography.

[0040] Furthermore, perfluoropolyether oil has a kinematic viscosity of 15 to 600 mm at 40°C. ２ It is preferable to use one in the range of / s, between 20 and 500 mm. ２ It is more preferable that the value be / s. The kinematic viscosity can be measured according to the method of JIS Z8803.

[0041] In the emulsion of the present invention, one type of perfluoropolyether oil (A) represented by the above formula (I) may be used alone, or two or more types may be used in combination.

[0042] From the viewpoint of emulsification stability, the content of perfluoropolyether oil (A) in the emulsion of the present invention is preferably 0.2 to 40% by mass, more preferably 0.4 to 30% by mass, even more preferably 1 to 25% by mass, particularly preferably 2 to 20% by mass, and most preferably 5 to 15% by mass, based on 100% by mass of the total amount of the emulsion.

[0043] (B) A perfluoropolyether carboxylate represented by the following formula (II).

[0044]

[0045] Rf'' is a perfluoroalkyl group having 1 to 4 carbon atoms. Examples of perfluoroalkyl groups having 1 to 4 carbon atoms include trifluoromethyl group, perfluoroethyl group, perfluoro-n-propyl group, perfluoro-isopropyl group, perfluoro-n-butyl group, perfluoro-isobutyl group, perfluoro-sec-butyl group, and perfluoro-tert-butyl group.

[0046] C in equation (II) ３ F ６ The base is CF ２ CF ２ CF ２ It may also be a base, CF(CF ３ )CF ２ It may also be a base, CF ２ CF (CF ３ ) It may be a base, but CF ２ CF ２ CF ２ Base or CF (CF ３ )CF ２ The base is preferred, CF(CF ３ )CF ２ The base is preferable.

[0047] X is a fluoro group or a trifluoromethyl group, with a trifluoromethyl group being preferred.

[0048] Y is a single bond or a divalent group having 1 to 10 carbon atoms. Preferably, the divalent group having 1 to 10 carbon atoms is a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms. Examples of substituted or unsubstituted divalent hydrocarbon groups having 1 to 10 carbon atoms include a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 4 to 10 carbon atoms, a substituted or unsubstituted arylene group having 6 to 10 carbon atoms, or a substituted or unsubstituted aralkylene group having 7 to 10 carbon atoms.

[0049] The divalent groups having 1 to 10 carbon atoms are preferably substituted or unsubstituted alkylene groups having 1 to 8 carbon atoms, substituted or unsubstituted alkenylene groups having 2 to 8 carbon atoms, substituted or unsubstituted cycloalkylene groups having 4 to 8 carbon atoms, substituted or unsubstituted arylene groups having 6 to 8 carbon atoms, or substituted or unsubstituted aralkylene groups having 7 to 8 carbon atoms; more preferably substituted or unsubstituted alkylene groups having 1 to 6 carbon atoms, substituted or unsubstituted alkenylene groups having 2 to 6 carbon atoms, substituted or unsubstituted cycloalkylene groups having 4 to 6 carbon atoms, or substituted or unsubstituted arylene groups having 6 carbon atoms; even more preferably substituted or unsubstituted alkylene groups having 1 to 6 carbon atoms; and particularly preferably (unsubstituted) alkylene groups having 1 to 6 carbon atoms.

[0050] When a hydrocarbon group has substituents, examples of substituents that substitute for hydrogen atoms in the hydrocarbon group include halogen atoms, hydroxyl groups, thiol groups, amide groups, guanidide groups, nitro groups, and cyano groups. When a hydrocarbon group has substituents, the number of substituents is preferably 1 to 5, and more preferably 1 to 3. Furthermore, if there are multiple substituents, the substituents may be the same or different.

[0051] Furthermore, as a substituent hydrocarbon group, a divalent group containing at least one heteroatom such as an oxygen atom, nitrogen atom, or sulfur atom may be interposed between the carbon-carbon atoms of the hydrocarbon group. The number of heteroatoms can preferably be 1 to 10, more preferably 1 to 6. Examples of divalent groups containing at least one heteroatom include -O-, -N<, -S-, and -SO ２ Examples include -, -(C=O)-, -(C=O)O-, -O(C=O)-, -NH(C=O)-, -(C=O)NH-, -NH(C=O)O-, -O(C=O)NH-, etc. When such divalent groups are interposed between the carbon atoms of a hydrocarbon group, the hydrocarbon chain is interrupted by these groups. Furthermore, the presence of such divalent groups between the carbon atoms of a hydrocarbon group may result in a heterocyclic structure.

[0052] In one embodiment, the following groups are examples of divalent groups having 1 to 10 carbon atoms represented by Y: -(CH ２ ) Ｎ１ - (N1=1~10) -A-(CH ２ ) Ｎ２ - (N2=1~5) -B-(CH ２ ) Ｎ３ - (N3=1~5) -CH ２ CH ２ (OCH ２ CH ２ ) Ｎ４ - (N4=1~4) -BCO(OCH ２ CH ２ ) Ｎ５ - (N5 = 1 to 4) (In the formula, A represents -O-CO-, -CO-O-, -CONH-, or -NHCO-. B represents phenylene which may have 1 to 3 substituents selected from the group consisting of C1-C3 alkyl groups (methyl, ethyl, propyl), C1-C4 alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), and halogen atoms (F, Cl, Br, I).)

[0053] Y is preferably a single bond or a divalent group with the following structure: -(CH ２ ) Ｎ１ - (N1=1~10) -CONH-(CH ２ ) Ｎ２ - (N2=1~5) -CO-O-(CH ２ ) Ｎ２ - (N2 = 1 to 5) n is 7 to 20, preferably 9 to 18.

[0054] M is an alkali metal, an ammonium base, or an organic amine base. Examples of alkali metals include lithium, sodium, and potassium. Examples of amine bases include trimethylamine, triethylamine, benzylamine, methylbenzylamine, dimethylbenzylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, and pyridine. Note that a countercation consisting of an alkali metal, an amine base, or an ammonium base may be introduced (salt formation) by a neutralization reaction with an acid compound (free acid) in which M is a hydrogen atom.

[0055] In the emulsion of the present invention, one perfluoropolyether carboxylate (B) represented by the above formula (II) may be used alone, or two or more may be used in combination.

[0056] The perfluoropolyether carboxylate (B) described above preferably has a weight-average molecular weight of 1,700 or more, and more preferably 1,800 or more. Furthermore, it is preferable that the weight-average molecular weight be 3,500 or less, and more preferably 3,000 or less. The weight-average molecular weight can be measured by conventionally known methods such as gel filtration chromatography.

[0057] Specific examples of perfluoropolyether carboxylic acid compounds that are precursors to the above-mentioned perfluoropolyether carboxylic acid compound salt (B) include, but are not limited to, the following.

[0058]

[0059] (In the formula, n is between 7 and 20.)

[0060]

[0061] (In the formula, n is between 7 and 20.)

[0062]

[0063] (In the formula, n is between 7 and 20.)

[0064]

[0065] (wherein n is 7 to 20.) Perfluoropolyether carboxylate salt (B) can be produced by known methods. For example, it can be obtained by hydrolysis of a perfluoropolyether compound represented by the following formula (III).

[0066]

[0067] (In the formula, Rf'' is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a single bond or a divalent group having 1 to 10 carbon atoms. R is a substituted or unsubstituted hydrocarbon group. n is 7 to 25.)

[0068] In equation (III), Rf'', X, Y, and n are the same as those defined in equation (II).

[0069] In formula (III), R is a substituted or unsubstituted hydrocarbon group. Preferably, it is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, more preferably a substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms, and particularly preferably a substituted or unsubstituted hydrocarbon group having 1 to 6 carbon atoms.

[0070] Examples of unsubstituted hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, allyl, benzyl, cyclopentyl, cyclohexyl, adamantyl, and phenyl groups. Preferably, the groups are methyl, ethyl, tert-butyl, and benzyl, with the methyl group being particularly preferred.

[0071] In R, if the hydrocarbon group has a substituent, any substituent listed above in Y of formula (II) can be used without particular limitation.

[0072] The perfluoropolyether compound represented by formula (III) above preferably has a weight-average molecular weight of 1,700 or more, and more preferably 1,800 or more. Furthermore, it is preferable that the weight-average molecular weight be 3,500 or less, and more preferably 3,000 or less. The weight-average molecular weight can be measured by conventionally known methods such as gel filtration chromatography.

[0073] The perfluoropolyether compound represented by formula (III) above can be synthesized using anionic ring-opening polymerization of hexafluoropropylene oxide. This reaction can be carried out by referring to the method disclosed, for example, in Japanese Patent Publication No. 5774470.

[0074] From the viewpoint of emulsification stability, the content of the perfluoropolyether carboxylate (B) in the emulsion of the present invention is preferably 0.005 to 8% by mass, more preferably 0.01 to 6% by mass, even more preferably 0.02 to 5% by mass, particularly preferably 0.05 to 4% by mass, and most preferably 0.1 to 3% by mass, based on 100% by mass of the total amount of the emulsion.

[0075] Furthermore, from the viewpoint of emulsification stability, the content of the perfluoropolyether carboxylate (B) in the emulsion of the present invention is preferably 1 to 20 parts by mass, more preferably 2 to 17 parts by mass, and particularly preferably 5 to 15 parts by mass, per 100 parts by mass of the perfluoropolyether oil (A).

[0076] (C) Water-soluble organic solvent Water-soluble organic solvent (C) has a mass-average water / octanol partition coefficient (logP) in the range of -0.33 to 0.

[0077] In this specification, the "mass-average value of the water / octanol partition coefficient (logP)" is the value obtained by calculating the water / octanol partition coefficient of each component contained in the water-soluble organic solvent by multiplying it by its respective mass fraction (the mass of each water-soluble organic solvent divided by the sum of the masses of all water-soluble organic solvents), and then summing these values. In other words, if the water-soluble organic solvent consists of only one component, the mass-average value of the water / octanol partition coefficient is the water / octanol partition coefficient of that water-soluble organic solvent itself. If the water-soluble organic solvent is a mixture of two or more components, the mass-average value of the water / octanol partition coefficient is the sum of the results obtained by multiplying the water / octanol partition coefficient of each of those organic solvents by their respective mass fractions.

[0078] From the viewpoint of emulsification stability, the mass-average value of the water / octanol partition coefficient (logP) of the water-soluble organic solvent (C) is -0.33 to 0, and preferably -0.30 to -0.10.

[0079] In this specification, "water-soluble organic solvent" means an organic solvent in which the amount of solvent dissolved in 100 g of water at 25°C is 10 g or more.

[0080] Examples of water-soluble organic solvents include alcoholic solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol, propylene glycol monomethyl ether, or glycerin; ketone solvents such as acetone; nitrile solvents such as acetonitrile; etheric solvents such as tetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, or triethylene glycol dimethyl ether; and dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone. By using one of these solvents alone or in combination of two or more, the mass-average value of the water / octanol partition coefficient (logP) can be set to a range of -0.33 to 0.

[0081] From the viewpoint of emulsification stability, the content of the water-soluble organic solvent (C) in the emulsion of the present invention is preferably 0.05 to 40% by mass, more preferably 0.1 to 20% by mass, and particularly preferably 0.5 to 10% by mass, based on 100% by mass of the total amount of the emulsion.

[0082] Furthermore, from the viewpoint of emulsification stability, the content of the water-soluble organic solvent (C) in the emulsion of the present invention is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass, and particularly preferably 10 to 50 parts by mass, per 100 parts by mass of the perfluoropolyether oil (A).

[0083] (D) Water The water (D) content in the emulsion of the present invention is preferably 50 to 99% by mass, more preferably 55 to 95% by mass, and particularly preferably 60 to 90% by mass, based on 100% by mass of the total amount of the emulsion, from the viewpoint of emulsification stability.

[0084] (Other Additives) The emulsion of the present invention may contain, as appropriate, rust inhibitors, catalysts, antibacterial agents, flame retardants, surfactants, defoaming agents, thickeners, viscosity modifiers, leveling agents, ultraviolet absorbers, preservatives, antifreeze agents, wetting agents, pH adjusters, stabilizers, light-resistant stabilizers, weather-resistant stabilizers, neutralizing agents, matting agents, drying accelerators, foaming agents, non-stick agents, degradation inhibitors, etc., within limits that do not impede the objectives of the present invention. These may be used individually or in combination of two or more. Each of these additives can be used in an amount ranging from 0.01 to 10 parts by mass per 100 parts by mass of the total of perfluoropolyether oil (A), perfluoropolyether carboxylate (B), and water-soluble organic solvent (C).

[0085] In one embodiment, the emulsion of the present invention preferably does not contain a thickening agent. When the emulsion does not contain a thickening agent, it can preferably be used as a lubricant. In particular, in embodiments as a lubricant, the emulsion of the present invention may contain additives (e.g., preservatives, antibacterial agents, rust inhibitors, etc.) as appropriate, as long as they do not hinder the purpose of the present invention, but it is most preferable that it does not contain any components other than perfluoropolyether oil (A), perfluoropolyether carboxylate (B), water-soluble organic solvent (C), and water (D).

[0086] <Method for producing the emulsion> The emulsion of the present invention can be produced by a method comprising the following steps (Step 1) and (Step 2). (Step 1) A step of preparing a dispersion containing perfluoropolyether oil (A), perfluoropolyether carboxylate (B), and water-soluble organic solvent (C). (Step 2) A step of mixing the dispersion with water (D).

[0087] In step 1, the mixing order in the dispersion is not particularly limited. Perfluoropolyether oil (A) may be mixed with perfluoropolyether carboxylate (B) and water-soluble organic solvent (C), or any other mixing order may be used. In addition, various additives may be mixed as desired. It is preferable to mix these components and stir them thoroughly to ensure that each component is uniformly dispersed.

[0088] The amount of perfluoropolyether carboxylate (B) mixed in the dispersion is preferably 1 to 20 parts by mass, more preferably 2 to 17 parts by mass, and particularly preferably 5 to 15 parts by mass, per 100 parts by mass of perfluoropolyether oil (A).

[0089] The amount of water-soluble organic solvent (C) mixed in the dispersion is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass, and particularly preferably 10 to 50 parts by mass, per 100 parts by mass of perfluoropolyether oil (A).

[0090] In step 2, it is preferable to gradually add water (D) to the dispersion obtained in step 1 while stirring. Gradually mixing water (D) into the dispersion makes it easier to uniformly disperse each component. By this method, an emulsion can be prepared without using an ultrasonic homogenizer or a high-pressure homogenizer.

[0091] The amount of water (D) mixed in step 2 is preferably 100 to 10,000 parts by mass, more preferably 120 to 5,000 parts by mass, even more preferably 150 to 2,000 parts by mass, particularly preferably 170 to 1,000 parts by mass, and most preferably 200 to 600 parts by mass, per 100 parts by mass of the dispersion.

[0092] Various additives can be optionally mixed into the emulsion obtained in this way.

[0093] <Applications of the Emulsion> The emulsion of the present invention can be used in a variety of applications, but is particularly preferred as a lubricant. As a lubricant, it can be used in applications such as home appliances, ships, railways, aircraft, machinery, structures, automobile repair, automobiles, construction, building materials, textiles, leather, stationery, woodworking, furniture, general merchandise, steel plates, cans, electronic circuit boards, electronic components, and printing. Among these, it is particularly useful in applications for automobiles and industrial machinery.

[0094] Furthermore, the emulsion of the present invention can also be used as a mold release agent, a water-repellent and oil-repellent agent, a fiber treatment agent, and the like.

[0095] When the emulsion of the present invention is used as a release agent, the molding material or resin material released using the emulsion of the present invention is not particularly limited, but examples include rubbers such as urethane rubber, H-NBR, NBR, silicone rubber, EPDM, CR, NR, fluororubber, SBR, BR, IIR and IR; urethane foam, epoxy resin, polyimide resin, polyamide resin, melamine resin, urea resin, polyurethane, silicone resin, alkyd resin, phenolic resin, unsaturated polyester resin, vinyl ester resin and thermosetting resins such as FRP (glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFRP)); PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), PS (polystyrene), PA (polyamide), polyester, polycarbonate, ABS resin, poly(meth)acrylic acid, polyacetal, polyvinylidene fluoride, polyphenylene sulfide, polyetherimide, polyetheretherketone, Examples include thermoplastic resins such as FRTP (glass fiber reinforced thermoplastic resin (GFRTP), carbon fiber reinforced thermoplastic resin (CFRTP), and aramid fiber reinforced thermoplastic resin (AFRTP)). In particular, they are useful as mold release agents for resins such as polyurethane and epoxy resins.

[0096] Furthermore, when the emulsion of the present invention is used as a mold release agent or a water- and oil-repellent agent, the material to which the emulsion of the present invention is applied is not particularly limited, but examples include metals such as aluminum, stainless steel, and iron; resins such as PP, PE, and epoxy; rubber; FRP (fiber-reinforced plastic); gypsum substrates; wooden substrates; fibers; glass; and composite materials. The emulsion of the present invention can impart high water-repellency and oil-repellency to these materials.

[0097] When the emulsion of the present invention is used as a fiber treatment agent, the fibers to be treated with the emulsion of the present invention may be in any form such as short fibers (fibers), lint, roving, sliver, yarn, woven fabric, knitted fabric, non-woven fabric, etc. Examples of the fiber material include cellulose fibers such as cotton, flax, jute, ramie, regenerated fiber cellulose, rayon, and polyvinyl alcohol-based synthetic fibers.

[0098] The emulsion of the present invention can be applied to the portion to be treated with the emulsion and dried for use. When applying, the emulsion may be diluted with water or the like. The concentration after dilution is appropriately selected according to the application method, viscosity, etc., and is not particularly limited. For example, it can be prepared so that the solid content concentration is 0.1 to 5% by mass. The application method is not particularly limited, and examples include spray application, brush application, roll coater application, dipping application, etc. The drying method includes a method of forming a film by evaporating the solvent by air drying or heating. The dry thickness of the film containing the emulsion of the present invention is preferably 0.01 to 15 μm, more preferably 0.1 to 5.0 μm.

[0099] Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.

[0100] (Materials used) ・ PFPE oil 1: Perfluoropolyether oil (RecaloFlosso PT82, manufactured by Nichika Chemical Co., Ltd., weight average molecular weight 2800, 49 mm 2 / s (40 °C)) RfO-(CFCF3CF2O) n -Rf’ ・ PFPE oil 2: Perfluoropolyether oil (RecaloFlosso PT05, manufactured by Nichika Chemical Co., Ltd., weight average molecular weight 5000, 200 mm 2 / s (40 °C)) RfO-(CFCF3CF2O) n -Rf’ ・ PFPE oil 3: Perfluoropolyether oil (RecaloFlosso PT57, manufactured by Nichika Chemical Co., Ltd., weight average molecular weight 7500, 440 mm 2 / s (40 °C)) RfO-(CFCF3CF2O) n-Rf’ · PFPE oil 4: Perfluoropolyether oil (Fomblin M07, manufactured by Solvay, weight average molecular weight 5400, 38 mm 2 / s (40 °C)) CF3O-(CF2CF2O) q -(CF2O) r -CF3 (q≈30, r≈30) · PFPE carboxylic acid 1: Perfluoropolyether carboxylic acid CF3CF2CF2O-[CF(CF3)CF2O] n -CF(CF3)-CONHCH2-COOH·Et3N (weight average molecular weight 2000, n = 10.) · PFPE carboxylic acid 2: Perfluoropolyether carboxylic acid CF3CF2CF2O-[CF(CF3)CF2O] n -CF(CF3)-COOH·Et3N (weight average molecular weight 2000, n = 10.) · PFPE carboxylic acid 3: Perfluoropolyether carboxylic acid CF3CF2CF2O-[CF(CF3)CF2O] n -CF(CF3)-COOH·DBU (weight average molecular weight 2000, n = 10.) · PFPE carboxylic acid 4: Perfluoropolyether carboxylic acid CF3CF2CF2O-[CF(CF3)CF2O] n -CF(CF3)-CONHCH2-COOH·Et3N (weight average molecular weight 1800, n = 9.) · PFPE carboxylic acid 5: Perfluoropolyether carboxylic acid CF3CF2CF2O-[CF(CF3)CF2O] n -CF(CF3)-CONHCH2-COOH·Et3N (weight average molecular weight 3000, n = 16.) · MeOH: Methanol (water / octanol partition coefficient: -0.77) · EtOH: Ethanol (water / octanol partition coefficient: -0.31) · nPrOH: 1-Propanol (water / octanol partition coefficient: 0.25) · IPA: 2-Propanol (water / octanol partition coefficient: 0.05) · PGM: Propylene glycol monomethyl ether (water / octanol partition coefficient: -0.21)· Acetone (water / octanol partition coefficient: -0.21) · DME: Dimethoxyethane (water / octanol partition coefficient: -0.22)

[0101] <Example 1> PFPE oil 1 (10.0 g), PFPE carboxylate 1 (1.0 g), and PGM (2.0 g) were placed in a 200 ml beaker containing a stirring bar. The mixture was stirred with a magnetic stirrer for 10 minutes to prepare a dispersion. While stirring the dispersion, distilled water (87.0 g) was gradually added dropwise to prepare an emulsion with a PFPE oil concentration of 10 wt%. The appearance of the emulsion after emulsification and the median diameter were measured. The results are shown in Table 1.

[0102] (Evaluation of Emulsion Appearance) The emulsified liquid was visually inspected. An A rating is considered a pass, while C and D ratings are considered a fail. A: Emulsified well and stable. C: Emulsifies, but is unstable and settles within a few minutes. D: Fails to emulsify and separates into layers.

[0103] (Median diameter measurement) The sample was diluted with water to achieve a measurable transmittance (80-90%) using a HORIBA LA-750 particle size distribution analyzer.

[0104] <Examples 2-16, Comparative Examples 1-6> Emulsions were prepared in the same manner as in Example 1, except that the composition was changed as shown in Tables 1-4. Subsequently, the appearance of the emulsified liquid and the median diameter were measured in the same manner as in Example 1. The results are shown in Tables 1-4.

[0105]

[0106]

[0107]

[0108]

[0109] In Examples 1-4 and Comparative Examples 1-3, when using a single solvent, stable emulsions of PFPE oil were obtained when using EtOH, PGM, acetone, and DME, which have water-octanol partition coefficients between -0.33 and 0. However, with MeOH (water-octanol partition coefficient of -0.77) and IPA (water-octanol partition coefficient of 0.05), fine-particle emulsions were not obtained, and stable emulsions could not be acquired.

[0110] In Examples 4 and 5 and Comparative Examples 4 and 5, studies were conducted using a mixed solvent of MeOH and nPrOH. The relationship between the mass-average partition coefficient of water-octanol between MeOH and nPrOH and emulsification stability was examined. Stable emulsions were obtained when the mass-average partition coefficient was between -0.33 and 0. On the other hand, stable emulsions were not obtained when the mass-average partition coefficient was outside this range.

[0111] In Examples 7-11, the emulsion stability was investigated by changing the type of PFPE carboxylate. In Examples 12-14, the emulsion stability was investigated by changing the type of PFPE oil. In all cases, a stable emulsion was obtained.

[0112] In Example 15, four types of mixed solvents (EtOH, nPrOH, IPA, and DME) were used for the study. In Example 16, a mixed solvent of EtOH and DME was used for the study. In all cases, a stable emulsion was obtained.

[0113] In Comparative Example 6, an attempt was made to prepare an emulsion without using a water-soluble organic solvent, but it was confirmed that the emulsion did not emulsify and instead separated into layers after stirring was stopped.

Claims

1. An emulsion comprising (A) a perfluoropolyether oil represented by the following formula (I), (B) a perfluoropolyether carboxylate salt represented by the following formula (II), (C) a water-soluble organic solvent, and (D) water, wherein the mass average value of the water / octanol partition coefficient (logP) of the water-soluble organic solvent (C) is in the range of -0.33 to 0. (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p, q, and r are each independent integers of 0 or more, and p + q + r = 3 to 120. C) ３ F ６ O group, C ２ F ４ O group, and CF ２ The oxygen groups may be attached in any order. (In the formula, Rf'' is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a single bond or a divalent group having 1 to 10 carbon atoms. n is 7 to 20. M is an alkali metal, an ammonium base, or an organic amine base.) 2. The emulsion according to claim 1, wherein the weight-average molecular weight of the perfluoropolyether oil (A) is in the range of 1,000 to 20,000.

3. The emulsion according to claim 1, wherein the weight-average molecular weight of the perfluoropolyether carboxylate (B) is in the range of 1,800 to 3,000.

4. The emulsion according to claim 1, wherein the content of the perfluoropolyether carboxylate (B) is 1 to 20 parts by mass per 100 parts by mass of the perfluoropolyether oil (A).

5. The emulsion according to claim 1, wherein the content of the water-soluble organic solvent (C) is 5 to 100 parts by mass per 100 parts by mass of the perfluoropolyether oil (A).

6. A lubricant comprising the emulsion described in claim 1.

7. A method for producing an emulsion according to claim 1, comprising the steps of preparing a dispersion containing the perfluoropolyether oil (A), the perfluoropolyether carboxylate (B), and the water-soluble organic solvent (C), and mixing the dispersion with water (D).

8. The manufacturing method according to claim 7, wherein the amount of water (D) mixed with 100 parts by mass of the dispersion is 100 to 10,000 parts by mass.

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