Preparation method and application of fluorine-containing polyether carboxylic acid allyl ester

Abstract

The invention discloses a preparation method and application of fluorine-containing polyether carboxylic acid allyl ester, and relates to the technical field of preparation and application of fluorine-containing polyether carboxylic acid allyl ester, the preparation method comprises the following steps: S1, adding an allyl alcohol reagent into a reactor, and introducing nitrogen; s2, adding perfluoropolyether carboxylic acid with the molecular weight of 550-1000 according to the molar ratio of the allyl alcohol reagent to the perfluoropolyether carboxylic acid of (1.0-1.5): 1, stirring and heating to 85-120 DEG C, and reacting for 4-10 hours to obtain a crude product; s3, the crude product is subjected to extraction, liquid separation, drying and suction filtration, purified fluorine-containing polyether carboxylic acid allyl ester is obtained, the obtained fluorine-containing polyether carboxylic acid allyl ester can replace perfluoroalkyl substances to prepare a leather treating agent and a fabric surface treating agent, the leather treating agent and the fabric surface treating agent have the excellent hydrophobic and oleophobic performance of a fluorine surfactant, and meanwhile the environment-friendly requirement is met.

Description

Technical Field

[0001] The invention relates to the technical field of preparation and application of fluorine-containing polyether carboxylic acid allyl ester, and in particular to a preparation method and application of fluorine-containing polyether carboxylic acid allyl ester. Background Art

[0002] As people's quality of life improves, multifunctional finishing of textiles is gaining attention and favor, and the application of functional finishing agents is becoming more and more extensive. Similarly, the call for the development of new and efficient fabric finishing agents is getting louder and louder. Fluorine atoms have high electronegativity and high bond energy of fluorocarbon chains, which makes organic fluorine-based fabric finishing agents have unique performance advantages. With their unique water-repellent, oil-repellent, anti-fouling, washable, weather-resistant and breathable properties, they have become the mainstream product for water-repellent and oil-repellent treatment in the textile industry and other industries.

[0003] The unique properties of fluorine-containing chemicals are related to the properties of fluorine atoms and carbon-fluorine bonds: First, because fluorine is the element with the highest electronegativity, the bond energy of carbon-fluorine (CF) bonds is very high. Second, the atomic radius of covalently bonded fluorine atoms is larger than that of hydrogen atoms, which can effectively protect the fully fluorinated CC bonds. Therefore, the surface energy of fluorocarbon chains is extremely low, and liquids are difficult to spread on their surfaces. When water droplets or oil droplets contact the surface of fabrics treated with fluorine-containing finishing agents, water droplets or oil droplets will form and roll down, and will not penetrate into the fabric. This creates the characteristics of low concentration and high effect of fluorine-containing fabric finishing agents, so that the treated fabrics can maintain their original color, good hand feel, excellent air permeability and moisture permeability, high wearing comfort, corrosion resistance, and washing resistance. Fluorine-containing fabric finishing agents have obvious advantages over traditional silicone, nitrogen benzene, paraffin and other ordinary finishing agents in terms of water and oil repellency, stain resistance, washing resistance, friction resistance, corrosion resistance, etc., and have therefore developed rapidly and become the mainstream of today's water and oil repellent finishing agents.

[0004] In the prior art, perfluorooctyl compounds (PFOS) and perfluorohexyl compounds are widely used in the field of fabric finishing due to their friendly characteristics. However, with the development of technology, studies have shown that PFOS / PFOA fluorosurfactants are one of the most difficult substances to degrade. They are not only persistent and bioaccumulative, but also have the possibility of long-distance environmental migration. Once an organism ingests PFOS / PFOA fluorosurfactants, they will be distributed in the human blood and liver. Due to their inherent stability, it is difficult to decompose through human metabolism. Therefore, the use of perfluorooctanoic acid, its salts and perfluorooctanoic acid-related compounds is restricted.

[0005] In the prior art, for example, the patent application with application number "201810742029.5" published on November 30, 2018 discloses a method for preparing fluorinated acrylates, including the following steps: short-chain perfluoroiodoalkane reacts with ethylene, and perfluoroalkylethyl iodide is obtained after separation and purification; perfluoroalkylethyl iodide is hydrolyzed, and perfluoroalkylethanol is obtained after separation and purification; perfluoroalkylethanol reacts with (meth)acrylic acid, and the product is obtained after separation and purification; this method synthesizes products that do not contain perfluorooctyl (C8), and although there is no potential risk of producing PFOA, perfluorohexyl substances will be produced. On September 20, 2024, the Official Journal of the European Union (OJEU) published (EU) 2024 / 2462, which revised Annex XVI of the REACH Regulation and added Article 79 on the control of perfluorohexanoic acid (PFHXA), its salts and PFHXA-related substances. The restriction will take effect on October 10, 2024. Therefore, the application of fluorinated acrylates is also subject to control requirements.

[0006] For example, the patent application with application number "201610434299.0" published on November 9, 2016 discloses a method for preparing a leather brightener. The method adopts trimethoxysilylpropyl vinyl ether, silicone glycol copolymer wax, perfluoropolyether oil, perfluoroalkyl ethyl acrylate, polyisobutylene, and N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide salt to mix and compound, which solves the shortcomings of silicone brighteners such as poor adhesion and easy hydrolysis. The polyether increases the wettability and emulsification and improves the brightness of the leather. However, with the further update of PFAS regulations, the application of this type of substance is still restricted. Summary of the invention

[0007] The object of the present invention is to provide a method for preparing fluorinated polyether carboxylic acid allyl ester. The obtained fluorinated polyether carboxylic acid allyl ester can replace perfluoroalkyl substances to prepare leather treatment agents and fabric surface treatment agents, so that they have the excellent water-repellent and oil-repellent properties of fluorinated surfactants and also meet environmental protection requirements.

[0008] The present invention is achieved through the following technical solutions: A method for preparing fluorinated polyether carboxylic acid allyl ester comprises the following steps: S1, adding an allyl alcohol reagent into a reactor and introducing nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 at a molar ratio of allyl alcohol reagent to perfluoropolyether carboxylic acid of 1.0-1.5:1, stir and heat to 85-120° C., react for 4-10 hours, and obtain a crude product; S3, extracting, separating, drying and filtering the crude product to obtain purified fluorinated polyether carboxylic acid allyl ester. The structural formula of the fluorinated polyether carboxylic acid allyl ester is as follows: CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COO-CH2-CH=CH2, or CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COO-CH2-CH2-O-COO-CH=CH2, or CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COO-CH2-CH2-OC(=O)-C(CH3)=CH2, or CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COO-CH2-C(=CH2)-COO-CH2-CH3, Wherein, m is 1 to 10, n / m is 0.01 to 0.05, and the fluorinated polyether carboxylic acid allyl ester should satisfy: Surface tension of 0.1% aqueous solution: 15.00~35.00mN / m; Dynamic viscosity at 25°C: 1500~5000mPa•s.

[0009] The perfluoropolyether carboxylic acid is prepared by sequentially subjecting a perfluoroolefin, oxygen and a third monomer to photooxidation, hydrolysis and deoxygenation treatment at -20 to -25°C and normal pressure. The third monomer is an olefin or alkyne containing at least one non-fluorine atom. The general structural formula of the perfluoropolyether carboxylic acid is as follows: CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COOH, Wherein, m is 1 to 10, n / m is 0.01 to 0.05, and the perfluoropolyether carboxylic acid satisfies: Acid value: <150mg / g; Peroxygen value: 0.001~1%; Boiling point: 110-320℃.

[0010] Furthermore, in step S1, the allyl alcohol reagent includes one of allyl alcohol, diethylene glycol monoacrylate, ethylene glycol monomethacrylate, and 2-(hydroxymethyl)ethyl acrylate.

[0011] Furthermore, in step S1, the nitrogen introduction rate is 5-30 L / h. Preferably, the nitrogen introduction time is not less than 30 min.

[0012] Furthermore, in step S2, the rate of adding perfluoropolyether carboxylic acid is 15-40 g / min.

[0013] Further, in step S3, the steps of separating and purifying the crude product are: a1. The crude product obtained in S2 is mixed evenly with a saturated sodium carbonate solution at a mass ratio of 1.0-3.0:1, stirred at room temperature for 0.5-2h, placed in a liquid separator for standing and phase separation, and then the oil phase is taken to obtain product 1; a2. Mix the product 1 obtained in step a1 with ultrapure water in a mass ratio of 1.0-3.0:1, stir for 0.5-2h at 20-50°C, place in a liquid separator, let stand, separate phases, and take the oil phase to obtain product 2; a3. Place the product 2 obtained in step a2 in a vacuum drying oven, dry for 4 to 8 hours at 50 to 85° C. and a vacuum degree of -0.08 to -0.095, and filter to obtain purified fluorinated polyether carboxylic acid allyl ester.

[0014] Application of the fluorinated polyether carboxylic acid allyl ester obtained by any of the above-mentioned preparation methods in the preparation of leather treatment agents and fabric surface treatment agents.

[0015] Furthermore, the surface tension of a 0.1% aqueous solution of fluorinated polyether carboxylic acid allyl ester is 15.00-35.00 mN / m; and the dynamic viscosity at 25° C. is 1500-5000 mPa•s.

[0016] Furthermore, the leather treatment agent and fabric surface treatment agent include the following components by weight percentage: Surfactant 0.5~6%; Fluorinated polyether carboxylic acid allyl ester 6~20%; Acrylate monomer 5~15%; Initiator 0.1~1%; Solvent 2~20%; Water 50~70%.

[0017] Further, the surfactant includes one of Span 60, Span 80, Span 20, Tween 80 and Tween 60; The initiator includes one or a combination of azobisisobutyronitrile, azobisisoheptanenitrile, ammonium persulfate and potassium persulfate; The cosolvent is one or a mixture of ethylene glycol, propylene glycol, and isopropanol; The acrylic acid ester monomer is one or more of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate.

[0018] Furthermore, the preparation method of the leather treatment agent and the fabric surface treatment agent is as follows: a surfactant, an initiator, a cosolvent and deionized water are added to a reaction device, and then fluorinated polyether acrylate and acrylate are added to the reaction device, and stirred to prepare a pre-emulsion; the reaction temperature is 55-95°C, and the reaction time is 2-6h to obtain the leather treatment agent and the fabric surface treatment agent.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. In the present invention, the surface tension of a 0.1% aqueous solution of the fluorinated polyether carboxylic acid allyl ester prepared by the method is stable at 15.00-35.00 mN / m, and can be used as an intermediate for preparing an environmentally friendly fluorinated polyether waterproof finishing agent. It has the excellent water-repellent and oil-repellent properties of fluorinated surfactants, and does not contain PFOS / PFOA during the preparation process, which is green and environmentally friendly.

[0020] 2. In the present invention, safe and environmentally friendly perfluoropolyether carboxylic acid is used as the main raw material to prepare the fluorinated polyether carboxylic acid allyl ester, which effectively avoids the environmental problems of perfluoroalkyl substances.

[0021] 3. In the present invention, no solvent, catalyst, etc. are used in the reaction process, the types of reactants are reduced, the product mainly includes fluorinated polyether carboxylic acid allyl ester and water, the product has few by-products, and the complexity of the subsequent impurity removal process is reduced. At the same time, the amount of washing water is reduced, the generation of waste liquid is reduced, it is environmentally friendly, and the production cost is reduced.

[0022] Fourth, in the present invention, the post-treatment of the product is mainly carried out by physical methods such as drying and filtering, which effectively avoids the addition of chemical reagents, simplifies the operation process, and reduces production costs.

[0023] 5. In the present invention, the perfluoropolyether carboxylic acid reactant has a variety of molecular weights to choose from, and the prepared fluorinated polyether carboxylic acid allyl ester system is large and can meet the performance requirements of various fluorinated polyether waterproof finishing agent intermediates.

[0024] 6. The present invention also proposes the use of fluorinated polyether carboxylic acid allyl ester in the preparation of leather treatment agents and fabric surface treatment agents, and provides a formula and preparation method of leather treatment agents and fabric surface treatment agents. The synthesis reaction has no catalytic reaction conditions and utilizes temperature, reaction rate and other methods to promote the forward reaction. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0026] In the following examples, the perfluoropolyether carboxylic acid used was prepared by the following steps: Ⅰ. Take a perfluoroolefin and control its temperature at -20~-25°C, then pass a mixed gas consisting of oxygen and a third monomer of an olefin or alkyne containing at least one non-fluorine atom into the perfluoroolefin, keep the ultraviolet lamp irradiation and ventilation time for 2~12 hours, and then recover the unreacted perfluoroolefin after evaporation at room temperature to obtain a product containing an acyl fluoride terminal group; Ⅱ. After mixing the deionized water and the product containing acyl fluoride end groups, the temperature of the liquid phase fluid in the material prepared in step Ⅰ is controlled to be 30-50°C by stirring, and the product containing acyl fluoride end groups is continuously added to the prepared material at a rate of 10-60 L / h, and the stirring time is controlled to be 1-5 h; III. The crude product obtained in step II is allowed to stand and separated into layers, and the supernatant is removed to obtain a fluorinated oligomer having a carboxyl group at one end; IV. After the fluorinated oligomer is thermally decomposed and stabilized, it is distilled and cut according to the use requirements to obtain fluorinated carboxylic acid components with different molecular weight distributions; Ⅴ. Select perfluoropolyether carboxylic acid with a molecular weight of 550~1000 for use.

[0027] The general structural formula of the perfluoropolyether carboxylic acid is as follows: CF3-O-(-CF3CF-CF2-O-) m -(-CF2-O-) n -COOH, Wherein, m is 1 to 10, n / m is 0.01 to 0.05, and the perfluoropolyether carboxylic acid satisfies: Acid value: <150mg / g; Peroxygen value: 0.001~1%; Boiling point: 110-320℃.

[0028] Example 1 A method for preparing fluorinated polyether carboxylic acid allyl ester, which relates to the technical field of preparation and application of fluorinated polyether carboxylic acid allyl ester, comprises the following steps: S1, adding propylene alcohol into the reactor and introducing nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 in a certain proportion, stir and heat to a preset temperature, and react for 4-10 hours; S3. After adding reagents, extraction, liquid separation, drying and suction filtration, the purified fluorinated polyether carboxylic acid allyl ester is obtained. The process conditions of each experimental group in this embodiment are shown in Table 1.

[0029] Table 1 The properties of the prepared fluorinated polyether carboxylic acid allyl ester were tested again. The test results are shown in Table 2.

[0030] Table 2 As shown in Tables 1 and 2, the molecular weight of the selected perfluoropolyether carboxylic acid has a great influence on the viscosity of the final fluorinated polyether carboxylic acid allyl ester product. By selecting the specific molecular weight of the perfluoropolyether carboxylic acid and controlling the feed ratio of the specific molecular weight perfluoropolyether carboxylic acid and propylene alcohol, fluorinated polyether carboxylic acid allyl ester products with different acid values, different critical micelle concentrations, different specific gravities and different viscosities can be obtained, which can be used as intermediates of waterproof finishing agents. In addition, by appropriately increasing the carboxylic acid feed ratio, increasing the reaction temperature, and extending the reaction time, the conversion rate of the reactants can be improved.

[0031] Example 2 A method for preparing fluorinated polyether carboxylic acid allyl ester, which relates to the technical field of preparation and application of fluorinated polyether carboxylic acid allyl ester, comprises the following steps: S1, add 2-hydroxyethyl acrylic acid (molecular weight 116.12) into the reactor and introduce nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 in a certain proportion, stir and heat to a preset temperature, and react for 4-10 hours; S3. After adding reagents, extraction, liquid separation, drying and suction filtration, the purified fluorinated polyether carboxylic acid allyl ester is obtained. The process conditions of each experimental group in this embodiment are shown in Table 3.

[0032] Table 3 The properties of the prepared fluorinated polyether carboxylic acid allyl ester were tested again. The test results are shown in Table 4.

[0033] In this embodiment, the detection method and reference standard involved are the same as those in Example 1.

[0034] Table 4 As shown in Tables 3 and 4, the molecular weight of the selected perfluoropolyether carboxylic acid has a great influence on the viscosity of the final fluorinated polyether carboxylic acid allyl ester product. Similarly, by selecting the specific molecular weight of perfluoropolyether carboxylic acid and controlling the feed ratio of perfluoropolyether carboxylic acid of specific molecular weight to acrylic acid-2-hydroxyethyl, fluorinated polyether carboxylic acid allyl ester products with different acid values, different critical micelle concentrations, different specific gravities and different viscosities can be obtained, which can be used as intermediates of waterproof finishing agents. In addition, by appropriately increasing the carboxylic acid feed ratio, increasing the reaction temperature, and extending the reaction time, the conversion rate of the reactants can be improved, and the highest conversion rate can reach 94.11%.

[0035] Example 3 A method for preparing fluorinated polyether carboxylic acid allyl ester, which relates to the technical field of preparation and application of fluorinated polyether carboxylic acid allyl ester, comprises the following steps: S1, adding 2-hydroxyethyl methacrylate into a reactor, and introducing nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 in a certain proportion, stir and heat to a preset temperature, and react for 4-10 hours; S3. After adding reagents, extraction, liquid separation, drying and suction filtration, the purified fluorinated polyether carboxylic acid allyl ester is obtained. The process conditions of each experimental group in this embodiment are shown in Table 5.

[0036] Table 5 The properties of the prepared fluorinated polyether carboxylic acid allyl ester were tested again. The test results are shown in Table 6.

[0037] In this embodiment, the detection method and reference standard involved are the same as those in Example 1.

[0038] Table 6 As shown in Tables 5 and 6, the molecular weight of the selected perfluoropolyether carboxylic acid has a great influence on the viscosity of the final fluorinated polyether carboxylic acid allyl ester product. Similarly, by selecting the specific molecular weight of perfluoropolyether carboxylic acid and controlling the feed ratio of perfluoropolyether carboxylic acid of specific molecular weight to 2-hydroxyethyl methacrylate, fluorinated polyether carboxylic acid allyl ester products with different acid values, different critical micelle concentrations, different specific gravities and different viscosities can be obtained, which can be used as intermediates for waterproof finishing agents. In addition, by appropriately increasing the carboxylic acid feed ratio, increasing the reaction temperature, and extending the reaction time, the conversion rate of the reactants can be increased, and the highest conversion rate can reach 93.41%.

[0039] Example 4 A method for preparing fluorinated polyether carboxylic acid allyl ester, which relates to the technical field of preparation and application of fluorinated polyether carboxylic acid allyl ester, comprises the following steps: S1, adding ethyl 2-(hydroxymethyl)acrylate into a reactor, and introducing nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 in a certain proportion, stir and heat to a preset temperature, and react for 4-10 hours; S3. After adding reagents, extraction, liquid separation, drying and suction filtration, the purified fluorinated polyether carboxylic acid allyl ester is obtained. The process conditions of each experimental group in this embodiment are shown in Table 7.

[0040] Table 7 The properties of the prepared fluorinated polyether carboxylic acid allyl ester were tested again. The test results are shown in Table 8.

[0041] In this embodiment, the detection method and reference standard involved are the same as those in Example 1.

[0042] Table 8 As shown in Tables 7 and 8, the molecular weight of the selected perfluoropolyether carboxylic acid has a great influence on the viscosity of the final fluorinated polyether carboxylic acid allyl ester product. Similarly, by selecting the specific molecular weight of perfluoropolyether carboxylic acid and controlling the feed ratio of perfluoropolyether carboxylic acid of specific molecular weight and 2-(hydroxymethyl) ethyl acrylate, fluorinated polyether carboxylic acid allyl ester products with different acid values, different critical micelle concentrations, different specific gravities and different viscosities can be obtained, which can be used as intermediates of waterproof finishing agents. In addition, by appropriately increasing the carboxylic acid feed ratio, increasing the reaction temperature, and extending the reaction time, the conversion rate of the reactants can be increased, and the highest conversion rate can reach 93.09%.

[0043] Application Example 1 An environmentally friendly leather and fabric surface treatment agent, comprising the following components by weight percentage: Surfactant 0.5~6%; Fluorinated polyether carboxylic acid allyl ester 6~20%; Acrylates 5~15%; Initiator 0.1~1%; Solvent 2~20%; Deionized water 50~70%.

[0044] In this application example, the surfactant includes one of Span 60, Span 80, Span 20, Tween 80 and Tween 60.

[0045] In this application example, the initiator includes one or a combination of azobisisobutyronitrile, azobisisoheptanitrile, ammonium persulfate and potassium persulfate. In the following application group, azobisisobutyronitrile and ammonium persulfate are used as examples to conduct experiments and examine the performance of the products.

[0046] In this application example, the co-solvent is one or a mixture of ethylene glycol, propylene glycol, and isopropanol.

[0047] In this application example, the acrylic acid ester monomer is one or more of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate. In the following application group, isobornyl methacrylate, ethyl methacrylate, and methyl methacrylate are used as examples for experiments, and the performance of the products is examined.

[0048] In this application example, the fluorinated polyether carboxylic acid allyl ester includes one of the fluorinated polyether propylene alcohol ester, the fluorinated polyether glycol monoacrylate product, the fluorinated polyether glycol monomethacrylate product, and the 2-(hydroxymethyl)acrylate ethyl ester product prepared as in the above-mentioned Examples 1 to 4. In the following application groups, the fluorinated polyether carboxylic acid allyl ester obtained by Group 23 was used as an example for experiments, and the performance of the product was examined.

[0049] The preparation method of the environmentally friendly leather and fabric surface treatment agent comprises the following steps: (1) According to the mass ratio of materials in each application group in Table 9, add surfactant, initiator, cosolvent and deionized water into the reaction device, then add fluorinated polyether carboxylic acid allyl ester and acrylate substances into the reaction device, adjust the instruments and equipment as required, stir at high speed, and prepare the pre-emulsion.

[0050] (2) Dispense 50% of the pre-emulsion obtained in step (1) into a 500 ml flask to complete the construction of the reaction device. The reaction temperature is controlled at 80°C and the reaction time is 3 hours. In the specific implementation, the reaction temperature is controlled at 55-95°C and the reaction time is preferably 2-6 hours.

[0051] (3) Add the remaining pre-emulsion dropwise into the reaction system and continue the heat preservation reaction for 3 hours. In specific implementation, the heat preservation reaction time can be adjusted according to the amount of materials, and is generally controlled to be 2 to 6 hours.

[0052] (4) The final product is obtained through filtration and purification operations.

[0053] Table 9 .

[0054] Application Example 2 An environmentally friendly leather and fabric surface treatment agent, comprising the following components by weight percentage: Surfactant: Span 80 2%; Fluorinated polyether allyl ester: Group 10, 15% fluorinated polyether glycol monoacrylate; Acrylates: methyl methacrylate 12%; Initiator: azobisisobutyronitrile 0.5%; Cosolvent: Ethylene glycol: 15%; Deionized water 55.5%.

[0055] The preparation and method are the same as those in Application Example 1, and finally an environmentally friendly leather and fabric surface treatment agent is obtained.

[0056] The performance of the environmentally friendly leather and fabric surface treatment agents prepared according to Examples 1 and 2 was tested, and the test results are shown in Table 11.

[0057] The test methods and reference standards involved are as follows: The standard method is to use the national standard GB 4745-1997 to examine the waterproof effect and use AATCC-TEST Method118.1-1992 to examine the oil-proof effect.

[0058] (1) National Standard GB 4745-1997 Test Method Cut a sample of 18×18cm, press it with a clamp, and install it on a fixed base at a 45° angle to the horizontal. Quickly and steadily inject 250mL (20±2℃) of distilled water or deionized water into the funnel, and spray evenly and continuously toward the center of the sample through a nozzle at a distance from the center of the sample within 25 to 30 seconds. After spraying, quickly remove the clamp, make the sample face down and level, gently tap it twice, observe the degree of wetting of the sample, and then use text description and compare it with the picture to evaluate its level. Take the average of the two times.

[0059] The rating criteria are: Level 1: The entire surface is wetted.

[0060] Level 2: Half of the exposed surface is wetted, i.e. the sum of the wetted surfaces of the small patches is approximately half of the total area.

[0061] Level 3: Only small, intermittent areas of the exposed surface are wetted.

[0062] Level 4: The surface is not wet, but has small water droplets on it.

[0063] Level 5: The surface is not wet and there are no small water droplets.

[0064] (2) AATCC—TEST Method 118.1-1992 First, carefully drop 0.05 mL of the lowest numbered test liquid on the sample. If no penetration or wetting occurs within 30 seconds, then drop a higher numbered test liquid on the sample. The test continues until the test liquid wets the sample below or around the drop within 30 seconds. The oil repellency rating of the sample is represented by the highest numbered test liquid that cannot wet the sample within 30 seconds, and the rating is shown in Table 10 below.

[0065] Table 10 .

[0066] (3) Mechanical stability Mechanical stability is measured by adding the waterproof and oil-proof agent into a 5 ml centrifuge tube, centrifuging it at 3000 r / min for 30 minutes in a centrifuge, and observing whether the waterproof and oil-proof agent has any unstable phenomena such as floating, stratification and precipitation.

[0067] Table 11 .

[0068] From the above application examples and in combination with Tables 9 and 11, it can be seen that by using the fluorinated polyether carboxylic acid allyl ester prepared by this scheme and adding a specific amount of surfactant, acrylate substance, initiator, cosolvent, etc., an environmentally friendly leather and fabric surface treatment agent with excellent oleophobic performance can be obtained, and the waterproof level can reach level 5 and the oil-proof level can reach up to level 6 or 7. Most groups obtained stable mechanical properties of the final product.

[0069] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing fluorinated polyether carboxylic acid allyl ester, characterized in that: The following steps are involved: S1, adding an allyl alcohol reagent into a reactor and introducing nitrogen; S2, then add perfluoropolyether carboxylic acid with a molecular weight of 550-1000 at a molar ratio of allyl alcohol reagent to perfluoropolyether carboxylic acid of 1.0-1.5:1, stir and heat to 85-120° C., react for 4-10 hours, and obtain a crude product; S3. The crude product is extracted, separated, dried and filtered to obtain purified fluorinated polyether carboxylic acid allyl ester.

2. The method for preparing a fluorinated polyether carboxylic acid allyl ester according to claim 1, characterized in that: In step S1, the allyl alcohol reagent includes one of allyl alcohol, diethylene glycol monoacrylate, ethylene glycol monomethacrylate, and ethyl 2-(hydroxymethyl)acrylate.

3. The method for preparing a fluorinated polyether carboxylic acid allyl ester according to claim 1, characterized in that: In step S1, the nitrogen introduction rate is 5-30 L / h.

4. The method for preparing a fluorinated polyether carboxylic acid allyl ester according to claim 1, characterized in that: In the step S2, the rate of adding perfluoropolyether carboxylic acid is 15-40 g / min.

5. The method for preparing a fluorinated polyether carboxylic acid allyl ester according to claim 1, characterized in that: In step S3, the steps of separating and purifying the crude product are: a1. The crude product obtained in S2 is mixed evenly with a saturated sodium carbonate solution at a mass ratio of 1.0-3.0:1, stirred at room temperature for 0.5-2h, placed in a liquid separator for standing and phase separation, and then the oil phase is taken to obtain product 1; a2. Mix the product 1 obtained in step a1 with ultrapure water in a mass ratio of 1.0-3.0:1, stir for 0.5-2h at 20-50°C, place in a liquid separator, let stand, separate phases, and take the oil phase to obtain product 2; a3. Place the product 2 obtained in step a2 in a vacuum drying oven, dry for 4 to 8 hours at 50 to 85° C. and a vacuum degree of -0.08 to -0.095, and filter to obtain purified fluorinated polyether carboxylic acid allyl ester.

6. Use of the fluorinated polyether carboxylic acid allyl ester obtained by the preparation method according to any one of claims 1 to 5 in the preparation of leather treatment agents and fabric surface treatment agents.

7. The use according to claim 6, characterized in that: Fluorinated polyether carboxylic acid allyl ester: Surface tension of 0.1% aqueous solution: 15.00~35.00mN / m; dynamic viscosity at 25℃: 1500~5000mPa•s.

8. The use according to claim 7, characterized in that: The leather treatment agent and fabric surface treatment agent include the following components by weight percentage: Surfactant 0.5~6%; Fluorinated polyether carboxylic acid allyl ester 6~20%; Acrylate monomer 5~15%; Initiator 0.1~1%; Solvent 2~20%; Water 50~70%.

9. The use according to claim 8, characterized in that: The surfactant includes one of Span 60, Span 80, Span 20, Tween 80 and Tween 60; The initiator includes one or a combination of azobisisobutyronitrile, azobisisoheptylnitrile, ammonium persulfate and potassium persulfate; The cosolvent is one or a mixture of ethylene glycol, propylene glycol, and isopropanol; The acrylic acid ester monomer is one or more of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate.

10. The use according to claim 8, characterized in that: The preparation method of the leather treatment agent and the fabric surface treatment agent comprises: adding a surfactant, an initiator, a cosolvent and deionized water into a reaction device, then adding a fluorinated polyether acrylate and an acrylate into the reaction device, and stirring to prepare a pre-emulsion; The reaction temperature is 55-95°C, the reaction time is 2-6h, and a leather treating agent and a fabric surface treating agent are obtained.

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