A high-efficiency emulsification method for fluorocarbon compounds

Abstract

The invention discloses a highly efficient emulsification method for fluorocarbon compounds, belonging to the field of fine chemicals. After dissolving fluorocarbon compounds and polyisocyanates or polyacid chlorides with a fluorine-containing solvent, the mixture is dripped into deionized water containing a fluorocarbon surfactant and a hydrocarbon surfactant (ionic and non-ionic emulsifier) ​​under high-speed stirring, and a fluorine-containing water-in-oil emulsion with water as a continuous phase is formed after high-speed emulsification. The emulsion has low surface tension, uniform dispersion, and good stability, and can be used in the fields of fluorine-containing microcapsules, fluorine-containing soap-free emulsions, fluorine-containing finishing agents, etc.

Description

Technical Field

[0001] The invention relates to the technical field of emulsification and fine chemical industry, and in particular to a high-efficiency emulsification method of fluorocarbon compounds. Background Art

[0002] The fluorine element has the largest electronegativity, a particularly small covalent bond radius, a small polarizability, and a large carbon-fluorine (CF) bond energy. Due to the characteristics of the fluorine element, fluorocarbon polymers have many special properties, which are mainly reflected in: excellent chemical resistance, hydrophobicity and oil repellency, low surface energy, excellent weather resistance, high heat resistance, strong anti-fouling, etc. Therefore, they are widely used in fluororubber, fluororesin, fluorocoatings, surfactants, lubricants, etc.

[0003] Because fluorocarbon compounds are extremely inert, most existing fluorocarbon compounds are in the form of water-dispersible emulsions. At present, there are many studies on fluorine-containing emulsions in China, and the main problem is the selection of emulsifiers. Existing emulsion-type fluorine-containing emulsions are mostly emulsified using ordinary fluorine-free surfactants. The surfactants have low activity and are used in large quantities. The fluorine-containing monomers cannot be completely emulsified and participate in polymerization, resulting in a low fluorine content in the polymer, an unstable polymerization system, and a poor waterproofing effect. The emulsion cannot show good hydrophobic properties, which greatly limits the application scope of the fluorine-containing emulsion.

[0004] Chinese patent CN1927902A uses a nonionic emulsifier, nonylphenol polyoxyethylene ether, and an anionic emulsifier, perfluorooctanoic acid amine, as emulsifiers to prepare a water-based fluorine-containing emulsion through emulsion polymerization. Perfluorooctanoic acid amine has been identified by environmentalists as a persistent environmental pollutant due to its non-volatile and non-degradable characteristics by the ecosystem. Many countries have banned the use of perfluorooctanoic acid derivatives; while nonionic emulsifier nonylphenol polyoxyethylene ether will decompose into nonylphenol in the natural environment. Nonylphenol is a recognized environmental hormone that can simulate estrogen, affect the sexual development of organisms, interfere with the endocrine system of organisms, and is toxic to the reproductive system. EU member states have restricted its use. Chinese patent CN1861653A avoids the use of perfluorooctanoic acid amine as an emulsifier and replaces it with sodium dodecyl sulfate or sodium dodecyl sulfonate and nonylphenol polyoxyethylene ether as an emulsifier to prepare a cross-linkable water-based fluorine resin. Chinese patent CN1362422A uses sodium dodecyl sulfate, styrylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether to prepare water-based fluororesin. However, the role of perfluorooctanoic acid amine in the fluorine-containing emulsion polymerization process is quite obvious, and its emulsion system surface activity and emulsion stability have great advantages. The fluorine content of the resins prepared by the latter two without perfluorooctanoic acid amine as an emulsifier is much lower than that of the former. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide an efficient emulsification method for fluorocarbon compounds, which adopts a method of compounding fluorocarbon surfactants and hydrocarbon surfactants, and slowly drips a fluorocarbon compound solution system into deionized water containing a compound emulsifier of fluorocarbon surfactants and hydrocarbon surfactants (ionic emulsifiers and non-ionic emulsifiers) under high-speed rotation to form an oil-in-water emulsion. The method is simple to operate, saves resources, and is green and environmentally friendly. The fluorocarbon emulsion prepared by the method has low surface tension, is evenly dispersed, and has stable performance.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for emulsifying a fluorocarbon compound, wherein the raw materials are all calculated by weight, specifically comprising the following steps:

[0008] (1) Place 20-50 parts of polyisocyanate or polyacid chloride, 10-30 parts of fluorinated solvent and 100 parts of fluorocarbon in a container and stir appropriately to completely dissolve;

[0009] (2) Add 400-700 parts of deionized water into a reaction kettle, and add 1-5 parts of an ionic emulsifier, 1-10 parts of a nonionic emulsifier and 1-10 parts of a fluorocarbon surfactant into the water;

[0010] (3) At room temperature, slowly drip the mixed solution in (1) into the reaction kettle in (2) and emulsify at a speed of 2000 to 8000 rpm for 3 to 15 minutes to form a stable oil-in-water emulsion.

[0011] Preferably, the polyisocyanate is one or a mixture of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and diphenylmethane diisocyanate.

[0012] Preferably, the polyacyl chloride is one or a mixture of sebacic acid chloride, trimesic acid chloride, terephthaloyl chloride and terephthaloyl chloride.

[0013] Preferably, the fluorine-containing solvent is one or a mixture of methyl nonafluorobutyl ether, perfluoropolyether (PFPE), hydrofluorocarbon fluorocarbon solvents (HFCs), perfluorobutyl ethyl propyl ether, and 3-perfluorobutyl propanol.

[0014] Preferably, the fluorocarbon compound is hexafluorobutyl acrylate, hexafluorobutyl methacrylate, trifluoroethyl acrylate, trifluoroethyl methacrylate, perfluorobutyl ethylene, perfluorododecyl ethylene, perfluorotetradecyl ethylene, perfluorononyl ethylene, perfluorobutyl ethyl acrylate, perfluorobutyl ethyl methacrylate, perfluorododecyl ethyl acrylate, perfluorododecyl ethyl methacrylate, perfluorotetradecyl ethyl acrylate, perfluorotetradecyl ethyl methacrylate, perfluorononyl ethyl acrylate, perfluorononyl ethyl methacrylate, perfluorohexanone, trifluoroiodomethane, trifluoromonobromomethane, 1,1,2,2-tetrafluorodibromoethane, or a mixture of the foregoing.

[0015] Preferably, the ionic emulsifier is one or a mixture of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, potassium rosinate, potassium oleate, fatty acid potassium, potassium ricinoleate, and fatty alcohol polyoxyethylene ether sulfate.

[0016] Preferably, the nonionic emulsifier is one or a mixture of polyethylene glycol, Tween 80, Tween 20, OP-10, castor oil polyoxyethylene ether, polyoxyethylene ether, and alkyl alcohol amide polyoxyethylene ether.

[0017] Preferably, the fluorocarbon surfactant is one or a mixture of perfluorobutyl polyoxyethylene ether, perfluorohexyl polyoxyethylene ether, perfluorononyl polyoxyethylene ether, perfluorododecyl polyoxyethylene ether, and a water-soluble ethoxylated nonionic non-octacarbon fluorocarbon surfactant.

[0018] Compared with the prior art, the present invention provides an efficient emulsification method for fluorocarbon compounds, and prepares a fluorocarbon water-in-oil emulsion with water as the continuous phase. The emulsion has low surface tension and good stability, and can be used in the fields of fluorocarbon microcapsules, fluorine-containing soap-free emulsions, fluorine-containing finishing agents, etc., and has high practical application significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 The attached drawings are a particle size distribution diagram (a) and a surface tension diagram (b) of the fluorine-containing emulsion prepared in Example 1 of the present invention.

[0021] Figure 2 The attached drawings are a particle size distribution diagram (a) and a surface tension diagram (b) of the fluorine-containing emulsion prepared in Example 2 of the present invention.

[0022] Figure 3 The attached drawings are a particle size distribution diagram (a) and a surface tension diagram (b) of the fluorine-containing emulsion prepared in Example 3 of the present invention.

[0023] Figure 4 The attached drawings are a particle size distribution diagram (a) and a surface tension diagram (b) of the fluorine-containing emulsion prepared in Example 4 of the present invention. DETAILED DESCRIPTION

[0024] The following examples can provide a better understanding of the present invention, but are not intended to limit the present invention in any way.

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The idea of ​​the present invention is that the existing emulsion-type fluorine-containing emulsions are mostly emulsified using ordinary fluorine-free surfactants, the surfactants have low activity and are used in large amounts, the fluorocarbon compounds cannot be completely emulsified, and the emulsion system is unstable, resulting in low fluorine content in fluorine-containing microcapsules, fluorine-containing soap-free emulsions, and fluorine-containing finishing agents, which greatly limits the application scope of the fluorine-containing emulsions.

[0027] Fluorocarbons have a high fluorine content and poor solubility. Fluorocarbons are basically insoluble in polyisocyanates or polyacid chlorides. In order to improve the compatibility between the two, an appropriate amount of fluorine-containing solvent needs to be added. Also because of the high fluorine content of fluorocarbons, small molecule emulsifiers have insufficient affinity for fluorine-containing monomers, so a method of multi-compounding fluorocarbon surfactants and hydrocarbon surfactants is used. The composite emulsifiers have a synergistic effect, which can greatly reduce the surface energy of fluorocarbons and thus significantly reduce the surface tension of the solution, which is helpful for the emulsification of fluorocarbons, and thus can successfully emulsify fluorocarbons with poor solubility.

[0028] The present invention provides an efficient emulsification method for fluorocarbon compounds based on the surface tension and stability of the emulsion, and compounded fluorocarbon surfactants and hydrocarbon surfactants (ionic emulsifiers and non-ionic emulsifiers). It is found that the multi-component compounding of surfactants produces excellent synergistic effects. The fluorocarbon compound solution system is slowly dropped into deionized water containing fluorocarbon surfactants and hydrocarbon surfactant compound emulsifiers under high-speed rotation to form an oil-in-water emulsion. The prepared fluorocarbon emulsion has low surface tension, is evenly dispersed, and has stable performance.

[0029] Example 1

[0030] Preparation of protective solution: In a reaction container, methyl nonafluorobutyl ether, isophorone diisocyanate, and perfluorohexanone are added in sequence and mixed evenly to prepare a transparent and stable protective solution, the mass proportions of the three are 2 parts, 1 part, and 1.6 parts, respectively.

[0031] Preparation of emulsifier aqueous solution: In a reaction kettle, deionized water, a compound emulsifier, namely sodium dodecyl sulfate, polyethylene glycol and perfluorohexyl polyoxyethylene ether (FSN), are mixed and dissolved uniformly at room temperature to prepare a stable emulsifier aqueous solution, wherein the amount of the compound emulsifier added is 1% of the total mass of the stable emulsifier aqueous solution mixed system, and the mass proportions of sodium dodecyl sulfate, polyethylene glycol and perfluorohexyl polyoxyethylene ether (FSN) in the compound emulsifier are 1 part, 5 parts and 10 parts respectively.

[0032] Preparation of aqueous fluorocarbon emulsion: At 25°C, under stirring at a speed of 500 rpm, slowly add the protective solution to the emulsifier aqueous solution in the reactor, and the dropping speed is uniform. After the addition is completed, emulsify at a speed of 6000 rpm for 10 minutes to obtain the desired aqueous fluorocarbon emulsion. The protective solution accounts for 25% of the total mass of the mixed solution system, and its particle size distribution is uniform. The emulsion system has low surface tension, such as Figure 1 shown.

[0033] Example 2

[0034] Preparation of protective solution: In a reaction container, perfluoropolyether, isophorone diisocyanate, and trifluoromethane bromobromide are added in sequence and mixed evenly to prepare a transparent and stable protective solution, the mass proportions of the three are 2.5 parts, 1 part, and 2 parts respectively.

[0035] Preparation of emulsifier aqueous solution: In a reaction kettle, deionized water, a compound emulsifier, namely sodium dodecylbenzene sulfonate, OP-10 and perfluorobutyl polyoxyethylene ether, are mixed and dissolved uniformly at room temperature to prepare a stable emulsifier aqueous solution, wherein the amount of the compound emulsifier added is 1% of the total mass of the stable emulsifier aqueous solution mixed system, and the mass fractions of sodium dodecylbenzene sulfonate, OP-10 and perfluorobutyl polyoxyethylene ether in the compound emulsifier are 1 part, 5 parts and 10 parts respectively.

[0036] Preparation of aqueous fluorocarbon emulsion: At 25°C, under stirring at a speed of 300 rpm, slowly add the protective solution to the emulsifier aqueous solution in the reactor, with a uniform dropping speed. After the addition is completed, emulsify at a speed of 5000 rpm for 15 minutes to obtain the desired aqueous fluorocarbon emulsion. The protective solution accounts for 25% of the total mass of the mixed solution system, and its particle size distribution is uniform. The emulsion system has a low surface tension, such as Figure 2 shown.

[0037] Example 3

[0038] Preparation of protective solution: In a reaction container, perfluorobutyl ethyl propyl ether, terephthaloyl chloride, and perfluorododecyl ethyl acrylate are added in sequence and mixed evenly to prepare a transparent and stable protective solution. The mass proportions of the three are 2.5 parts, 1 part, and 2 parts, respectively.

[0039] Preparation of emulsifier aqueous solution: In a reaction kettle, deionized water, a compound emulsifier, namely sodium dodecyl sulfate, polyoxyethylene ether and perfluorohexyl polyoxyethylene ether (FSN), are mixed and dissolved uniformly at room temperature to prepare a stable emulsifier aqueous solution, wherein the amount of the compound emulsifier added is 0.5% of the stable emulsifier aqueous solution mixed system, and the mass proportions of sodium dodecyl sulfate, polyoxyethylene ether and perfluorohexyl polyoxyethylene ether (FSN) in the compound emulsifier are 1 part, 5 parts and 10 parts respectively.

[0040] Preparation of aqueous fluorocarbon emulsion: At 25°C, under stirring at a speed of 400 rpm, slowly add the protective solution to the emulsifier aqueous solution in the reactor, with a uniform dropping speed. After the addition is completed, emulsify at a speed of 8000 rpm for 5 minutes to obtain the desired aqueous fluorocarbon emulsion. The protective solution accounts for 25% of the total mass of the mixed solution system, and its particle size distribution is uniform. The emulsion system has a low surface tension, such as Figure 3 shown.

[0041] Example 4

[0042] Preparation of protective solution: In a reaction container, hydrofluorocarbon solvent (HFCs), diphenylmethane diisocyanate, and perfluorobutylene are added in sequence and mixed evenly to prepare a transparent and stable protective solution. The mass proportions of the three are 2.5 parts, 1 part, and 2 parts, respectively.

[0043] Preparation of emulsifier aqueous solution: In a reaction kettle, deionized water, a compound emulsifier, namely potassium oleate, polyoxyethylene ether and perfluorobutyl polyoxyethylene ether, are mixed and dissolved uniformly at room temperature to prepare a stable emulsifier aqueous solution, wherein the amount of the compound emulsifier added is 0.5% of the total mass of the stable emulsifier aqueous solution mixed system, and the mass proportions of potassium oleate, polyoxyethylene ether and perfluorobutyl polyoxyethylene ether in the compound emulsifier are 1 part, 5 parts and 10 parts respectively.

[0044] Preparation of aqueous fluorocarbon emulsion: At 25°C, under stirring at a speed of 300 rpm, slowly add the protective solution to the emulsifier aqueous solution in the reactor, with a uniform dropping speed. After the addition is completed, emulsify at a speed of 6000 rpm for 10 minutes to obtain the desired aqueous fluorocarbon emulsion. The protective solution accounts for 25% of the total mass of the mixed solution system, and its particle size distribution is uniform. The emulsion system has a low surface tension, such as Figure 4 shown.

Claims

1. A method for efficiently emulsifying fluorocarbon compounds, characterized in that: The specific steps include: (1) Place 20 to 50 parts by weight of polyisocyanate or polyacid chloride, 10 to 30 parts by weight of fluorinated solvent and 100 parts by weight of fluorocarbon in a container and stir evenly; (2) Add 400 to 700 parts by mass of deionized water into a reaction kettle, and add 1 to 5 parts by mass of an ionic emulsifier, 1 to 10 parts by mass of a nonionic emulsifier, and 1 to 10 parts by mass of a fluorocarbon surfactant into the water; (3) slowly dripping the mixed solution obtained in step (1) into the reaction kettle in step (2), and maintaining the emulsification at a speed of 2000 to 8000 rpm for 3 to 15 minutes to form a stable oil-in-water emulsion; Wherein, the fluorine-containing solvent is one or a mixture of methyl nonafluorobutyl ether, perfluoropolyether, hydrofluorocarbon fluorocarbon solvent, perfluorobutyl ethyl propyl ether, and 3-perfluorobutyl propanol; The fluorocarbon compound is one or a mixture of hexafluorobutyl (meth)acrylate, trifluoroethyl (meth)acrylate, perfluorobutylethylene, perfluorododecylethylene, perfluorotetradecylethylene, perfluorononylethylene, perfluorobutylethyl (meth)acrylate, perfluorododecylethyl (meth)acrylate, perfluorotetradecylethyl (meth)acrylate, perfluorononylethyl (meth)acrylate, perfluorohexanone, trifluoroiodomethane, trifluoromonobromomethane, and 1,1,2,2-tetrafluorodibromoethane; The fluorocarbon surfactant is one or a mixture of perfluorobutyl polyoxyethylene ether, perfluorohexyl polyoxyethylene ether, perfluorononyl polyoxyethylene ether, perfluorododecyl polyoxyethylene ether, and a water-soluble ethoxylated nonionic non-octacarbon fluorocarbon surfactant.

2. The method according to claim 1, characterized in that The polyisocyanate is one or a mixture of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and diphenylmethane diisocyanate.

3. The method according to claim 1, characterized in that The polyacid chloride is one of sebacoyl chloride, trimesoyl chloride, terephthaloyl chloride and terephthaloyl chloride, or a mixture of several of them.

4. The method according to claim 1, characterized in that: The ionic emulsifier is one or a mixture of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, potassium rosinate, potassium oleate, fatty acid potassium, potassium ricinoleate, and fatty alcohol polyoxyethylene ether sulfate.

5. The method according to claim 1, characterized in that: The nonionic emulsifier is one or a mixture of polyethylene glycol, Tween 80, Tween 20, OP-10, castor oil polyoxyethylene ether, polyoxyethylene ether, and alkyl alcohol amide polyoxyethylene ether.

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