Preparation method and application of fluoride-free water repellent agent for glass fiber air filter paper

Abstract

The invention discloses a preparation method of an efficient fluoride-free water repellent agent for glass fiber air filter paper. The fluorine-free water repellent agent emulsion is prepared by adopting a core-shell emulsion polymerization mode and a semi-continuous emulsion polymerization method. Butyl acrylate is used as a main core, and hydrophobic monomer vinyl polydimethylsiloxane is used as a main shell. The emulsion synthesized by the method serves as a siloxane group part of a shell part, can protect an inner membrane of an acrylic polymer, is beneficial for silane groups to extend into air and achieves an excellent hydrophobic effect, and meanwhile, the emulsion is consistent with glass fiber paper air filter paper dipping-acrylic acid glue in type, so that the compounding property of a water repellent agent and the acrylic acid glue can be remarkably improved, and the water repellent effect is improved. And the weight-average molecular weight of the polymer is controlled to be less than 100000, so that the permeability is further improved. The glass fiber air filter paper obtained by blending the fluorine-free water repellent agent emulsion prepared by the invention with a glass fiber paper filter paper dipping-acrylic acid adhesive emulsion, dipping and drying has the advantages of good water resistance, low gram weight and high stiffness, and has higher filtering efficiency compared with a common water repellent agent.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorine-free water repellent agents, and specifically relates to a preparation method and application of a fluorine-free water repellent agent for glass fiber air filter paper. Background Art

[0002] Glass fiber paper is prepared by adding corresponding chemical reagents to evenly disperse glass fibers in water to form a suspension, and then filtering and forming on a forming net. Glass fiber paper has a finer diameter and can achieve high filtering accuracy. At the same time, glass fiber paper has a high modulus and is relatively stiff, which makes the fiber diameter very small but not easy to aggregate. The stacking density is relatively low, so the filtering resistance is also low. The high efficiency and low resistance performance are the main reasons why glass fiber paper filter paper dominates the market. Therefore, it is widely used in the filter layer of various filters and is an important part of the filtering function. It can be used to filter dust and various aerosol particles in the atmosphere, and is widely used in industrial production, air compressor compressed air filtration, air conditioning filtration, vacuum cleaners, gas masks, etc.

[0003] Air filter paper with excellent performance should have high filtration accuracy, relatively low filtration resistance, high dirt holding capacity and long service life. Chinese patent CN 107686531 A provides a polyacrylate emulsion for impregnation of glass fiber air filter paper and its preparation method. The problems of powder and hair loss on the back of the glass fiber filter paper impregnated with the polyacrylate emulsion are improved and have good air permeability. The quality of glass fiber filter paper can be improved to a certain extent, but the hydrophobicity is poor. In a relatively humid environment, the air filter paper is easy to absorb water and soften, and the strength deteriorates, resulting in a decrease in filtration efficiency. At the same time, the life of the paper is shortened, and the application requirements of air filter paper cannot be met. Chinese patent CN 109320651A, organic siloxane monomer is directly added to the acrylic emulsion as a modification aid for modification, and a super-hydrophobic polyacrylate composite emulsion for impregnation of glass fiber paper is prepared by compounding with nano zinc oxide and silane coupling agent. The glass fiber filter paper impregnated with the polyacrylate composite emulsion has super-hydrophobic performance, good filtration efficiency, and good air permeability. However, the patent does not test the water resistance of the treated glass fiber filter paper. Chinese patent CN 116635129A provides a filter medium containing a fluorinated water repellent additive and a non-fluorinated water repellent additive, and improves the water resistance of the glass fiber filter paper by adding a waterproofing agent. However, in recent years, due to the increasing concern about the environmental and ecological problems caused by fluorinated compounds and the impact on human health, there is an urgent need to find a fluorine-free alternative that can provide good water resistance. Summary of the invention

[0004] Purpose of the invention: In view of this, the purpose of the present invention is to provide a method for preparing a high-efficiency fluorine-free water-repellent agent for glass fiber air filter paper and its application in preparing high-efficiency waterproof glass fiber air filter paper. It aims to improve the quality of glass fiber air filter paper while providing excellent water resistance and high stiffness, and has higher filtration efficiency than ordinary water-repellent agents.

[0005] Technical solution: The fluorine-free water repellent for glass fiber air filter paper of the present invention comprises the following components: 5-10 parts of mixed monomer, 20-25 parts of hydrophobic monomer, 0.5-3 parts of functional monomer, 10-20 parts of cosolvent, 40-60 parts of water, 0.5-3 parts of composite emulsifier, 0.1-1 parts of water-soluble initiator and 0.1-0.5 parts of chain transfer agent; the fluorine-free water repellent emulsion with a weight average molecular weight of 20000-60000 prepared from the above components;

[0006] The mixed monomer is selected from one or a combination of two or more of butyl acrylate, methyl methacrylate and ethyl acrylate;

[0007] The hydrophobic monomer is selected from a hydrophobic monomer composition of vinyl polydimethylsiloxane and one or two of octadecyl methacrylate, lauryl methacrylate, isobornyl methacrylate or isodecyl methacrylate; the mass proportion of the vinyl polydimethylsiloxane in the hydrophobic monomer composition is 50-80wt%;

[0008] The functional monomer is selected from one or a combination of two or more of N-methyl acrylamide, N-hydroxyethyl acrylamide, vinyl triethoxysilane, and tetramethyl tetravinyl cyclotetrasiloxane.

[0009] Furthermore, as a preferred embodiment, the co-solvent is selected from one of tripropylene glycol, tripropylene glycol monomethyl ether, dipropylene glycol, and dipropylene glycol monomethyl ether.

[0010] Furthermore, as a preferred embodiment, the composite emulsifier is a combination of sodium dodecylbenzene sulfonate (SDS) and one or two of alkylphenol polyoxyethylene ether (OP) and polyethylene oxide sorbitan monostearate (Tween).

[0011] Furthermore, as a preferred embodiment, the water-soluble initiator is ammonium persulfate or potassium persulfate.

[0012] Furthermore, as a preferred embodiment, the chain transfer agent is n-dodecyl mercaptan.

[0013] The present invention also provides a method for preparing the above-mentioned fluorine-free water repellent, comprising the following two stages:

[0014] 1) The first stage is the copolymerization of mixed monomers to form nuclear seeds: first, a certain amount of water and composite emulsifier are added to the reactor, and then the mixed monomers are emulsified with the composite emulsifier and added to the reactor, and part of the initiator is added dropwise, and the mixture is heated to 70-80°C, and the rotation speed of the electric stirrer is set to 150-200rmin. After the system reacts for about 10-20min, a blue phenomenon will appear. After 20-40min, a co-solvent is added dropwise and the mixture is balanced for 10min.

[0015] 2) The second stage is the dropwise addition reaction of the shell part containing the hydrophobic monomer: the hydrophobic monomer, the functional monomer and the chain transfer agent are mixed and emulsified with a composite emulsifier to obtain the shell part monomer, the emulsified shell part monomer and the remaining initiator are added dropwise respectively, and the continuous dropping is controlled within 2-4 hours; after the dropwise addition is completed, the system is heated to 80-90°C and kept warm for 1-2 hours; finally, the temperature is lowered and the material is discharged to obtain a white and slightly blue fluorine-free water-repellent emulsion.

[0016] Furthermore, as a preferred embodiment, the mass ratio of the initiator added in the first stage to the initiator added in the second stage is 1:3.

[0017] The present invention also provides the use of the above-mentioned fluorine-free water repellent in the preparation of waterproof glass fiber air filter paper, specifically: the fluorine-free water repellent emulsion and the acrylic emulsion are mixed uniformly in proportion at room temperature, wherein the mass proportion of the fluorine-free water repellent emulsion in the mixed liquid is 20wt% to 50wt%; then the mixed liquid is impregnated, coated or sprayed on the glass fiber base paper, and dried in a drying oven at 130-160°C to obtain the waterproof glass fiber air filter paper.

[0018] Beneficial effects:

[0019] 1. The present invention provides a method for preparing a high-efficiency fluorine-free water-repellent emulsion for glass fiber air filter paper. The fluorine-free water-repellent emulsion is prepared by a core-shell emulsion polymerization method and a semi-continuous emulsion polymerization method. The core is mainly composed of butyl acrylate and the shell is mainly composed of a hydrophobic monomer vinyl polydimethylsiloxane. The siloxane group part of the emulsion synthesized by this method as the shell part can protect the inner membrane of the acrylic polymer, which is beneficial for the silane group to extend into the air, thereby achieving an excellent hydrophobic effect.

[0020] 2. The fluorine-free water-repellent emulsion prepared by the present invention is of the same type as the glass fiber paper air filter paper impregnation-acrylic adhesive, which can significantly improve the compatibility of the water-repellent and the acrylic adhesive. The weight-average molecular weight of the polymer in the prepared fluorine-free water-repellent emulsion is less than 100,000, which further improves the permeability.

[0021] 3. The glass fiber air filter paper obtained by blending the fluorine-free water-repellent emulsion prepared by the scheme of the present invention with the glass fiber paper filter paper impregnation-acrylic latex and then impregnating and drying has the advantages of good water resistance, low weight, and high stiffness, and has higher filtration efficiency than ordinary water-repellent agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a particle size distribution diagram of the fluorine-free water repellent emulsion prepared in Example 1 of the present invention;

[0023] Figure 2 This is a molecular weight distribution diagram of the fluorine-free water repellent polymer prepared in Example 1 of the present invention;

[0024] Figure 3 This is the infrared spectrum of the fluorine-free water repellent polymer prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in 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] Unless otherwise specified, the reagents and raw materials used in the examples and comparative examples of the present invention were purchased from the market.

[0027] Example 1

[0028] 1. Preparation of fluorine-free water repellent emulsion

[0029] Preparation of emulsifier: Mix 2g sodium dodecylbenzene sulfonate, 2g alkylphenol polyoxyethylene ether-10, and 40g water and stir evenly for use.

[0030] Preparation of initiator: Mix 0.8g potassium persulfate and 40g water and stir evenly.

[0031] Preparation of acrylate core seed emulsion: Add 15g water and 10g emulsifier to the reactor, then add 12g butyl acrylate, 12g methyl methacrylate, 10g emulsifier, and 20g water, stir and mix evenly, then add to the reactor, add 10.2g initiator dropwise, heat to 75°C, and set the rotation speed of the electric stirrer to 180rmin. After the system reacts for about 15min, a blue color will appear. After 30min, add 20g tripropylene glycol dropwise and balance for 10min.

[0032] 60g vinyl polydimethylsiloxane, 32g octadecyl methacrylate, 4g N-hydroxymethyl acrylamide, 1.2g n-dodecyl mercaptan, 20g emulsifier, 139g water were stirred and emulsified at high speed, and the emulsified shell part and 30.6g initiator were added dropwise respectively, and the dripping was controlled to be completed within 3 hours. After the dropwise addition was completed, the system was heated to 85°C and kept warm for 1 hour. Finally, the temperature was lowered and the material was discharged to obtain a white, slightly light blue, fluorine-free water-repellent emulsion with a solid content of 30.5%.

[0033] like Figure 1 , which is a particle size distribution diagram of the fluorine-free water-repellent product obtained in this example; the particle size distribution test shows that the fluorine-free water-repellent emulsion prepared by the present invention has a narrow particle size distribution, with an average particle size of less than 200 nm, indicating that the emulsion is uniform.

[0034] like Figure 2 As shown, it is the molecular weight distribution diagram of the fluorine-free water repellent product obtained in this example. The molecular weight and distribution test show that the weight average molecular weight (Mw) of the fluorine-free water repellent polymer prepared by the present invention is 47184, and the distribution is relatively narrow.

[0035] like Figure 3 As shown, it is the infrared spectrum of the fluorine-free water-repellent product obtained in this embodiment. The characteristic peaks of the infrared spectrum show that the absorption peak at about 3000 is the characteristic peak of -OH and -NH, the absorption peak at about 1730 is the characteristic peak of aliphatic ester group C=O, the absorption peak at about 1100 is the characteristic peak of Si-O-Si, and the absorption peak at 750-800 is the characteristic peak of Si-C. The polymer was successfully synthesized.

[0036] 2. Preparation of glass fiber air filter materials

[0037] Take 1g of the prepared fluorine-free water-repellent emulsion, 3g of acrylic glue, and 96g of water, mix and stir evenly, spread the formed micro-glass fiber paper flatly, immerse it in the diluent for 30s, take it out, and cure it at 150°C for 10min to obtain the glass fiber air filter material.

[0038] Example 2

[0039] 1. Preparation of fluorine-free water repellent emulsion

[0040] Preparation of emulsifier: Mix 2g sodium dodecylbenzene sulfonate, 2g alkylphenol polyoxyethylene ether-10, and 40g water and stir evenly for use.

[0041] Preparation of initiator: Mix 0.8g ammonium persulfate and 40g water and stir evenly.

[0042] Preparation of acrylate core seed emulsion: Add 15g water and 10g emulsifier to the reactor, then add 10g butyl acrylate, 14g methyl methacrylate, 10g emulsifier, and 15g water, stir and mix evenly, then add to the reactor, add 10.2g initiator dropwise, heat to 70°C, and set the rotation speed of the electric stirrer to 150rmin. After the system reacts for about 20min, a blue color will appear. After 30min, add 30g tripropylene glycol methyl ether dropwise and balance for 10min.

[0043] 60g vinyl polydimethylsiloxane, 20g octadecyl methacrylate, 12g isobornyl methacrylate, 4g N-hydroxymethyl acrylamide, 1g n-dodecyl mercaptan, 20g emulsifier, 135g water were stirred and emulsified at high speed, and the emulsified shell part and 30.6g initiator were added dropwise respectively, and the dripping was controlled to be completed within 3 hours. After the dropwise addition was completed, the system was heated to 80°C and kept warm for 1 hour. Finally, the temperature was lowered and the material was discharged to obtain a white, slightly blue, fluorine-free water-repellent emulsion with a solid content of 30.6%.

[0044] 2. Preparation of glass fiber air filter materials

[0045] Take 1g of the prepared fluorine-free water-repellent emulsion, 3g of acrylic glue, and 96g of water, mix and stir evenly, spread the formed micro-glass fiber paper flatly, immerse it in the diluent for 30s, take it out, and cure it at 150°C for 10min to obtain the glass fiber air filter material.

[0046] Example 3

[0047] 1. Preparation of fluorine-free water repellent emulsion

[0048] Preparation of emulsifier: Mix 2g sodium dodecylbenzene sulfonate, 2g polyethylene oxide sorbitan monostearate-80, and 40g water and stir evenly for use.

[0049] Preparation of initiator: Mix 0.8g ammonium persulfate and 40g water and stir evenly.

[0050] Preparation of acrylate core seed emulsion: add 15g water and 10g emulsifier to the reactor, then add 20g butyl acrylate, 10g ethyl acrylate, 10g emulsifier and 15g water, stir and mix evenly, then add to the reactor, add 10.2g initiator, heat to 80°C, and set the rotation speed of the electric stirrer to 180rmin. After the system reacts for about 20min, a blue color will appear. After 30min, add 30g dipropylene glycol methyl ether and balance for 10min.

[0051] 65g vinyl polydimethylsiloxane, 20g octadecyl methacrylate, 5g lauryl methacrylate, 4g vinyl triethoxysilane, 1g n-dodecyl mercaptan, 20g emulsifier, 130g water were stirred and emulsified at high speed, and the emulsified shell part and 30.6g initiator were added dropwise respectively, and the dripping was controlled to be completed within 3 hours. After the dropwise addition was completed, the system was heated to 90°C and kept warm for 1 hour. Finally, the temperature was lowered and the material was discharged to obtain a white, slightly light blue, fluorine-free water-repellent emulsion with a solid content of 30.1%.

[0052] 2. Preparation of glass fiber air filter materials

[0053] Take 1g of the prepared fluorine-free water-repellent emulsion, 3g of acrylic glue, and 96g of water, mix and stir evenly, spread the formed micro-glass fiber paper flatly, immerse it in the diluent for 30s, take it out, and cure it at 150°C for 10min to obtain the glass fiber air filter material.

[0054] Example 4

[0055] 1. Preparation of fluorine-free water repellent emulsion

[0056] Preparation of emulsifier: Mix 2g sodium dodecylbenzene sulfonate, 1g alkylphenol polyoxyethylene ether-10, 1g polyethylene oxide sorbitan monostearate-80, and 40g water and stir evenly for use.

[0057] Preparation of initiator: Mix 0.8g potassium persulfate and 40g water and stir evenly.

[0058] Preparation of acrylate core seed emulsion: Add 10g water and 10g emulsifier to the reactor, then add 10g butyl acrylate, 15g methyl methacrylate, 10g emulsifier, and 30g water, stir and mix evenly, then add to the reactor, add 10.2g initiator dropwise, heat to 75°C, and set the rotation speed of the electric stirrer to 180rmin. After the system reacts for about 15min, a blue color will appear. After 30min, add 20g dipropylene glycol methyl ether dropwise and balance for 10min.

[0059] 65g vinyl polydimethylsiloxane, 20g octadecyl methacrylate, 10g isodecyl methacrylate, 4g vinyl triethoxysilane, 0.8g n-dodecyl mercaptan, 20g emulsifier, 130g water were stirred and emulsified at high speed, and the emulsified shell part and 30.6g initiator were added dropwise respectively, and the dripping was controlled to be completed within 3 hours. After the dropwise addition was completed, the system was heated to 85°C and kept warm for one hour. Finally, the temperature was lowered and the material was discharged to prepare a white, slightly light blue, fluorine-free water-repellent emulsion with a solid content of 30.9%.

[0060] 2. Preparation of glass fiber air filter materials

[0061] Take 1g of the prepared fluorine-free water-repellent emulsion, 3g of acrylic glue, and 96g of water, mix and stir evenly, spread the formed micro-glass fiber paper flatly, immerse it in the diluent for 30s, take it out, and cure it at 150°C for 10min to obtain the glass fiber air filter material.

[0062] Comparative Example 1

[0063] The types and amounts of reagents in Example 1 remain unchanged, the polymerization method is changed to microemulsion polymerization, and one-time feeding is adopted to prepare a fluorine-free waterproofing agent emulsion, which is white and has no blue light.

[0064] Comparative Example 2

[0065] The chain transfer agent in Example 1 was removed, and other amounts and operations remained unchanged.

[0066] Comparative Example 3

[0067] The 60 g of vinyl polydimethylsiloxane and 32 g of octadecyl methacrylate in Example 1 were replaced with 32 g of vinyl polydimethylsiloxane and 60 g of octadecyl methacrylate, and the other amounts and operations remained unchanged.

[0068] Effect verification:

[0069] 1. Emulsion particle size test

[0070] The particle size of the fluorine-free water repellent emulsions prepared in Examples 1-4 of the present invention and Comparative Examples 1-3 was tested by using a Mastersizer 2000 laser particle size analyzer (Malvern, UK) to test the size and distribution of the latex particles.

[0071] 2. Polymer molecular weight test

[0072] The molecular weight was determined by a Waters 150C gel permeation chromatograph (Ultrast Yagel column 100, 1000A) at 30°C using THF as the eluent and a series of monodisperse polystyrene standards for calibration.

[0073] 3. Stability test of compounding with acrylic adhesive

[0074] The fluorine-free water repellent emulsions prepared in Examples 1-4 and Comparative Examples 1-3 of the present invention were compounded with acrylic adhesive at a compounding mass ratio of 1:3, and the static stability was tested to observe the precipitation after 7 days.

[0075] 4. Filtration efficiency and filtration resistance test

[0076] The filtration efficiency and filtration resistance of the glass fiber filter papers prepared in Examples 1-4 and Comparative Examples 1-3 of the present invention were tested using an American TSI-8130 automatic filter material tester.

[0077] 5. Stiffness test

[0078] The stiffness test of the glass fiber filter paper prepared in Examples 1-4 of the present invention and Comparative Examples 1-3 was performed

[0079] 6. Hydrostatic pressure test

[0080] The glass fiber filter papers prepared in Examples 1-4 and Comparative Examples 1-3 of the present invention were subjected to a hydrostatic pressure test according to the national standard GB / T4744-2013.

[0081] The results are shown in the following chart:

[0082] Test data:

[0083]

[0084]

[0085] From the results in the table, it can be seen that the fluorine-free water-repellent emulsion is prepared by the semi-continuous emulsion polymerization method using the core-shell emulsion polymerization method, which can significantly improve the compatibility of the water-repellent and acrylic adhesive, and the obtained emulsion is white with blue light, with a smaller particle size, and the hydrophobic monomer mainly composed of siloxane is used as the shell, which is conducive to the silane group extending into the air, achieving an excellent water-repellent effect. At the same time, the weight-average molecular weight of the polymer is controlled to be less than 50,000 to further improve the permeability and achieve a higher filtration efficiency.

[0086] The above is only an implementation method of the invention, and does not limit the scope of patent protection. Those skilled in the art can make non-substantial changes or substitutions based on the invention, which still fall within the scope of patent protection.

Claims

1. A fluorine-free water repellent for glass fiber air filter paper, characterized in that The invention comprises the following components: 5-10 parts of mixed monomer, 20-25 parts of hydrophobic monomer, 0.5-3 parts of functional monomer, 10-20 parts of cosolvent, 40-60 parts of water, 0.5-3 parts of composite emulsifier, 0.1-1 parts of water-soluble initiator and 0.1-0.5 parts of chain transfer agent; the fluorine-free water-repellent emulsion with a weight average molecular weight of 20000-60000 prepared by the above components; The mixed monomer is selected from one or a combination of two or more of butyl acrylate, methyl methacrylate and ethyl acrylate; The hydrophobic monomer is selected from a hydrophobic monomer composition of vinyl polydimethylsiloxane and one or two of octadecyl methacrylate, lauryl methacrylate, isobornyl methacrylate or isodecyl methacrylate; the mass proportion of the vinyl polydimethylsiloxane in the hydrophobic monomer composition is 50-80wt%; The functional monomer is selected from one or a combination of two or more of N-methyl acrylamide, N-hydroxyethyl acrylamide, vinyl triethoxysilane, and tetramethyl tetravinyl cyclotetrasiloxane.

2. The fluorine-free water repellent for glass fiber air filter paper according to claim 1, characterized in that: The co-solvent is selected from one of tripropylene glycol, tripropylene glycol monomethyl ether, dipropylene glycol and dipropylene glycol monomethyl ether.

3. The fluorine-free water repellent for glass fiber air filter paper according to claim 1, characterized in that: The composite emulsifier is a composition of sodium dodecylbenzene sulfonate and one or two of alkylphenol polyoxyethylene ether and polyethylene oxide sorbitan monostearate.

4. The fluorine-free water repellent for glass fiber air filter paper according to claim 1, characterized in that: The water-soluble initiator is ammonium persulfate or potassium persulfate.

5. The fluorine-free water repellent for glass fiber air filter paper according to claim 1, characterized in that: The chain transfer agent is n-dodecyl mercaptan.

6. A method for preparing the fluorine-free water repellent according to any one of claims 1 to 5, characterized in that It includes the following two stages: 1) The first stage is the copolymerization of mixed monomers to form nuclear seeds: first, a certain amount of water and composite emulsifier are added to the reactor, and then the mixed monomers are emulsified with the composite emulsifier and added to the reactor, and part of the initiator is added dropwise, and the mixture is heated to 70-80°C, and the rotation speed of the electric stirrer is set to 150-200rmin. After the system reacts for 10-20min, a blue phenomenon will appear. After 20-40min, a co-solvent is added dropwise and the mixture is balanced for 10min. 2) The second stage is the dropwise addition reaction of the shell part containing the hydrophobic monomer: the hydrophobic monomer, the functional monomer and the chain transfer agent are mixed and emulsified with a composite emulsifier to obtain the shell part monomer, the emulsified shell part monomer and the remaining initiator are added dropwise respectively, and the continuous dropping is controlled within 2-4 hours; after the dropwise addition is completed, the system is heated to 80-90°C and kept warm for 1-2 hours; finally, the temperature is lowered and the material is discharged to obtain a white and slightly blue fluorine-free water-repellent emulsion.

7. The method for preparing the fluorine-free water repellent according to claim 6, characterized in that: The mass ratio of the initiator added in the first stage to the initiator added in the second stage is 1:

3.

8. Use of the fluorine-free water repellent agent according to any one of claims 1 to 7 in the preparation of waterproof glass fiber air filter paper, characterized in that: The fluorine-free water-repellent emulsion and the acrylic emulsion are mixed uniformly at room temperature in proportion, wherein the mass proportion of the fluorine-free water-repellent emulsion in the mixed liquid is 20wt% to 50wt%; then the mixed liquid is impregnated, coated or sprayed on the glass fiber base paper, and dried in a drying oven at 130-160°C to obtain the waterproof glass fiber air filter paper.

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