Emulsion and method for producing the same

Abstract

This invention provides an emulsion of perfluoropolyether carboxylic acid that can be prepared by a simple method. [Solution] 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 formulas (I) and (II), 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.) JPEG2026059377000022.jpg9169 JPEG2026059377000023.jpg8169

Description

[Technical Field]

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

[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. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 1995 / 18194 [Patent Document 2] Japanese Patent Publication No. 2020-158600 [Overview of the Initiative] [Problems that the invention aims to solve]

[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. [Means for solving the problem]

[0006] In order to solve the above problems, the inventors conducted extensive research and found that a perfluoropolyether oil emulsion can be easily prepared by using perfluoropolyether oil, a perfluoropolyether carboxylate, an aqueous organic solvent with a specific range of mass average values ​​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] [Section 1] (A) A perfluoropolyether oil represented by the following formula (I), (B) A perfluoropolyether carboxylate represented by the following formula (II), (C) A water-soluble organic solvent, (D)Water An emulsion containing, An emulsion in which the mass-average value of the water / octanol partition coefficient (logP) of the aforementioned water-soluble organic solvent (C) is in the range of -0.33 to 0. [ka] (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 greater, and p+q+r=3 to 120. The C3F6O group, C2F4O group, and CF2O group may be bonded in any order.) [ka] (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.) [Section 2] The emulsion according to item 1, wherein the weight-average molecular weight of the perfluoropolyether oil (A) is in the range of 1,000 to 20,000. [Section 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. [Claim 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 with respect to 100 parts by mass of the perfluoropolyether oil (A). [Claim 5] The emulsion according to any one of claims 1 to 4, wherein the content of the water-soluble organic solvent (C) is 5 to 100 parts by mass with respect to 100 parts by mass of the perfluoropolyether oil (A). [Claim 6] A lubricant containing the emulsion according to any one of claims 1 to 5. [Claim 7] A step of preparing a dispersion containing the perfluoropolyether oil (A), the perfluoropolyether carboxylate (B), and the water-soluble organic solvent (C), and A step of mixing the dispersion and the water (D) The method for producing an emulsion according to any one of claims 1 to 5, comprising: [Claim 8] The production method according to claim 7, wherein the mixing amount of the water (D) with respect to 100 parts by mass of the dispersion is 100 to 10,000 parts by mass.

Effect of the Invention

[0009] According to the present invention, an emulsion of perfluoropolyether carboxylic oil that can be prepared by a simple method can be provided.

Mode for Carrying Out the Invention

[0010] <Emulsion> The emulsion according to the present invention contains the following (A) to (D). (A) A perfluoropolyether oil represented by the following formula (I). [Chemical formula] (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 greater, and p+q+r=3 to 120. The C3F6O group, C2F4O group, and CF2O group may be bonded in any order.) (B) A perfluoropolyether carboxylate represented by the following formula (II). [ka] (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 whose mass-average water / octanol partition coefficient (logP) is in the range of -0.33 to 0. (D) Water. The following provides a detailed explanation of each component.

[0011] (A) Perfluoropolyether oil represented by formula (I). [ka]

[0012] Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. Examples of perfluoroalkyl groups having 1 to 3 carbon atoms include trifluoromethyl, perfluoroethyl, perfluoro-n-propyl, and perfluoroisopropyl groups.

[0013] p, q, and r are each independent non-negative integers such that p+q+r=3 to 120. It is preferable that p+q+r be between 5 and 100, and more preferably between 10 and 80.

[0014] The C3F6O group, C2F4O group, and CF2O group may be bonded in any order. Here, "the C3F6O group, C2F4O group, and CF2O group are bonded in any order" means that the main chain of perfluoropolyether oil (A) has a configuration in which one or more repeating units of the C3F6O group, one or more repeating units of the C2F4O group, and one or more repeating units of the CF2O group are randomly arranged, and there is no regularity in the arrangement of the number of repeating units of the C3F6O group, the number of repeating units of the C2F4O group, and the number of repeating units of the CF2O group in the direction of the main chain. Also, the C3F6 group in formula (I) may be a CF2CF2CF2 group, a CF(CF3)CF2 group, or a CF2CF(CF3) group. The C2F4 group in formula (I) may be a CF2CF2 group or a CF(CF3) group.

[0015] Examples of such perfluoropolyether oils include those having structures represented by the following general formulas (Ia) to (Id). [ka] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p is between 3 and 120.) [ka] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p+r = 3 to 120. The CF(CF3)CF2O group and the CF2O group may be bonded in any order.) [ka] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. q+r = 3 to 120. The CF2CF2O group and the CF2O group may be bonded in any order.) [ka] (In the formula, Rf and Rf' are the same or different perfluoroalkyl groups having 1 to 3 carbon atoms. p is between 3 and 120.)

[0016] In formula (Ia), p is between 3 and 120, preferably between 5 and 100, more preferably between 10 and 80, and particularly preferably between 15 and 50.

[0017] 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.

[0018] In equation (Ic), q:r is preferably in the range of 10:90 to 90:10. q+r is between 3 and 120, preferably between 5 and 100, and more preferably between 10 and 80.

[0019] In formula (Id), p is between 3 and 120, preferably between 20 and 100, and more preferably between 40 and 80.

[0020] Examples of commercially available perfluoropolyether oils include the Krytox series (manufactured by DuPont), FomblinY series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), FomblinM series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), FomblinW series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), FomblinZ series (manufactured by Solvay Specialty Polymers Japan Co., Ltd.), DemnamS series (manufactured by Daikin Industries, Ltd.), and RecaloFlosso PT series (manufactured by Nikka Chemical Co., Ltd.).

[0021] 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.

[0022] Furthermore, perfluoropolyether oil has a kinematic viscosity of 15-600 mm at 40°C. 2 It is preferable to use one in the range of / s, 20 to 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.

[0023] 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.

[0024] 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.

[0025] (B) A perfluoropolyether carboxylate represented by the following formula (II). [ka]

[0026] 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.

[0027] In formula (II), the C3F6 group may be a CF2CF2CF2 group, a CF(CF3)CF2 group, or a CF2CF(CF3) group, but a CF2CF2CF2 group or a CF(CF3)CF2 group is preferred, and a CF(CF3)CF2 group is more preferred.

[0028] X is a fluoro group or a trifluoromethyl group, with a trifluoromethyl group being preferred.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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-, -SO2-, -(C=O)-, -(C=O)O-, -O(C=O)-, -NH(C=O)-, -(C=O)NH-, -NH(C=O)O-, and -O(C=O)NH-. When such a divalent group is interposed between the carbon-carbon atoms of the hydrocarbon group, the hydrocarbon chain is interrupted by these groups. Also, the presence of such a divalent group between the carbon-carbon atoms of the hydrocarbon group may result in a structure having a heterocycle.

[0033] In one embodiment, examples of a divalent group having 1 to 10 carbon atoms represented by Y include the following groups. -(CH2) N1 - (N1=1~10) -A-(CH2) N2 - (N2=1~5) -B-(CH2) N3 - (N3=1~5) -CH2CH2(OCH2CH2) N4 - (N4=1~4) -BCO(OCH2CH2) N5 - (N5=1~4) (In the formula, A represents -O-CO-, -CO-O-, -CONH- or -NHCO-. B represents a phenylene group which may have 1 to 3 substituents selected from the group consisting of an alkyl group having 1 to 3 carbon atoms (methyl, ethyl, propyl), an alkoxy group having 1 to 4 carbon atoms (methoxy, ethoxy, propoxy, butoxy, etc.), and a halogen atom (F, Cl, Br, I).)

[0034] Y is preferably a single bond or a divalent group having the following structure. -(CH2) N1 - (N1 = 1 to 10) -CONH-(CH2) N2 - (N2 = 1 to 5) -CO-O-(CH2) N2 - (N2 = 1 to 5) n is 7 to 20, preferably 9 to 18.

[0035] M is an alkali metal, an ammonium base or an organic amine base. Examples of the alkali metal include lithium, sodium, potassium, etc. Examples of the amine base include trimethylamine, triethylamine, benzylamine, methylbenzylamine, dimethylbenzylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, pyridine, etc. Regarding the counter cation consisting of an alkali metal, an amine base, or an ammonium base, it may be introduced (salt formation) by performing a neutralization reaction with an acid compound (free acid) in which M is a hydrogen atom.

[0036] In the emulsion of the present invention, the perfluoropolyether carboxylate (B) represented by the above formula (II) may be used alone or in combination of two or more.

[0037] 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.

[0038] 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. [ka] (In the formula, n is between 7 and 20.) [ka] (In the formula, n is between 7 and 20.) [ka] (In the formula, n is between 7 and 20.) [ka] (In the formula, n is between 7 and 20.)

[0039] Perfluoropolyether carboxylate salts (B) can be produced by known methods. For example, they can be obtained by hydrolysis of a perfluoropolyether compound represented by the following formula (III). [ka] (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.)

[0040] In equation (III), Rf'', X, Y, and n are the same as those defined in equation (II).

[0041] 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.

[0042] 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 group is methyl, ethyl, tert-butyl, or benzyl, with the methyl group being particularly preferred.

[0043] In R, if the hydrocarbon group has substituents, any substituents listed above in Y of formula (II) can be used without particular limitation.

[0044] 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.

[0045] 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.

[0046] From the viewpoint of emulsification stability, the content of 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.

[0047] 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).

[0048] (C) Water-soluble organic solvent For water-soluble organic solvent (C), the mass-average value of the water / octanol partition coefficient (logP) is in the range of -0.33 to 0.

[0049] 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.

[0050] 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 preferably between -0.30 and -0.10, with a range of -0.30 to -0.10.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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).

[0055] (D)Water From the viewpoint of emulsification stability, 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.

[0056] (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).

[0057] 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).

[0058] <Method for manufacturing emulsion> The emulsion of the present invention can be produced by a method comprising the following steps (1) and (2). (Step 1) A step to prepare a dispersion containing perfluoropolyether oil (A), perfluoropolyether carboxylate (B), and water-soluble organic solvent (C). (Step 2) A step in which the dispersion and water (D) are mixed.

[0059] 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 needed. It is preferable to mix these components and stir them thoroughly to ensure that each component is uniformly dispersed.

[0060] 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).

[0061] 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).

[0062] 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, emulsions can be prepared without using an ultrasonic homogenizer or a high-pressure homogenizer.

[0063] 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 dispersion.

[0064] Various additives can be mixed into the emulsion obtained in this way, as needed.

[0065] <Uses of emulsions> 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.

[0066] 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.

[0067] When the emulsion of the present invention is used as a release agent, the molded 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, as well as thermosetting resins such as 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 FRP (glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFRP)), as well as 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 (GFRTP), carbon fiber reinforced thermoplastic (CFRTP), and aramid fiber reinforced thermoplastic (AFRTP)). In particular, they are useful as mold release agents for resins such as polyurethane and epoxy resins.

[0068] 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, SUS, 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.

[0069] When the emulsion of the present invention is used as a fiber treatment agent, the fibers treated using the emulsion of the present invention may be in any form, such as short fibers, linters, rovings, slivers, yarns, woven fabrics, knitted fabrics, nonwoven fabrics, etc. Examples of fiber materials include cotton, flax, jute, hemp, ramie, regenerated cellulose, cellulose fibers such as rayon, and polyvinyl alcohol-based synthetic fibers.

[0070] The emulsion of the present invention can be used by applying it to the part to be treated with the emulsion and drying it. The emulsion may be diluted with water or other solvents as needed during application. The concentration after dilution is appropriately selected depending on the application method and viscosity, and is not particularly limited, but 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 includes, for example, spray application, brush application, roll coater application, and dipping application. Drying methods include air drying or heating to evaporate the solvent and form a film. The dry thickness of the film containing the emulsion of the present invention is usually 0.01 to 15 μm, preferably 0.1 to 5.0 μm. [Examples]

[0071] The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

[0072] (Materials used) • PFPE oil 1: Perfluoropolyether oil (RecaloFlosso PT82, manufactured by Nikka Chemical, weight-average molecular weight 2800) RfO-(CFCF3CF2O) n -Rf' • PFPE oil 2: Perfluoropolyether oil (RecaloFlosso PT05, manufactured by Nikka Chemical, weight-average molecular weight 5000) RfO-(CFCF3CF2O) n -Rf' • PFPE Oil 3: Perfluoropolyether oil (RecaloFlosso PT57, manufactured by Nikka Chemical, weight-average molecular weight 7500) RfO-(CFCF3CF2O) n -Rf' • PFPE oil 4: Perfluoropolyether oil (Fomblin M07, manufactured by Solvay, weight-average molecular weight 5400) 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 (Partition coefficient for water / octanol: -0.77) • EtOH: Ethanol (Partition coefficient of water / octanol: -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)

[0073] <Example 1> PFPE oil 1 (10.0g), PFPE carboxylate 1 (1.0g), and PGM (2.0g) were placed in a 200ml 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 (87.0g) 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.

[0074] (Evaluation of emulsion appearance) The emulsified liquid was visually inspected. ○: Emulsified well and stable. △: It emulsifies, but its stability is poor and it gradually settles. ×: Unable to emulsify, resulting in layering.

[0075] (Measuring median diameter) The particle size distribution was measured using a HORIBA LA-750 particle size distribution analyzer by diluting the sample with water to achieve a measurable transmittance (80-90%).

[0076] <Examples 2-16, Comparative Examples 1-6> Emulsions were prepared in the same manner as in Example 1, except for changes to the composition 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.

[0077] [Table 1]

[0078] [Table 2]

[0079] [Table 3]

[0080] [Table 4]

[0081] 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.

[0082] In Examples 4 and 5 and Comparative Examples 4 and 5, a mixed solvent of MeOH and nPrOH was used for the study. 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 0.05 or -0.36.

[0083] 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.

[0084] In Example 15, studies were conducted using four types of mixed solvents (EtOH, nPrOH, IPA, and DME). In Example 16, studies were conducted using a mixed solvent of EtOH and DME. In all cases, a stable emulsion was obtained.

[0085] 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. (A) A perfluoropolyether oil represented by the following formula (I), (B) A perfluoropolyether carboxylate represented by the following formula (II), (C) Water-soluble organic solvent and (D) Water An emulsion containing, An emulsion in which 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. 【Chemistry 1】 (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. 【Chemistry 2】 (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 step of preparing a dispersion containing the perfluoropolyether oil (A), the perfluoropolyether carboxylate (B), and the water-soluble organic solvent (C), and A step of mixing the dispersion and the water (D). A method for producing the emulsion according to claim 1, including the following:

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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