Fluorine-free waterproof oil-proof barrier material, fluoride-free waterproof oil-proof paper and preparation method of fluoride-free waterproof oil-proof barrier material

Abstract

The invention provides a fluoride-free waterproof and oil-proof barrier material, fluoride-free waterproof and oil-proof paper and a preparation method thereof, and relates to the technical field of waterproof and oil-proof packaging paper. The fluoride-free waterproof and oil-proof barrier material comprises a component A and a solution B in a mass ratio of (5-8): (2-5), wherein the solution B is a chitosan solution with the mass fraction of 1-3wt%; the component A is shown in the specification. Two silane coupling agent modified epoxy silicone oil and a chitosan solution are compounded to obtain the fluoride-free waterproof and oil-proof barrier material, in a component A, the reaction activity and function adjustability of an organosilicon polymer are greatly enhanced through introduction of amino groups, grafted 3-methacryloyloxypropyltrimethoxysilane can form a cross-linked network, and the barrier property is improved; the cohesive strength and the interface bonding force are obviously enhanced, and the waterproof and oil-proof performance is excellent. By adding chitosan, the film-forming property can be improved, a film with low surface energy is obtained on the surface of paper, and the film has excellent water-proof, oil-proof, green and environment-friendly barrier properties. The structural formula of the component A is shown in the specification.

Description

Technical Field

[0001] This invention relates to the field of waterproof and oil-proof packaging paper technology, and in particular to a fluorine-free waterproof and oil-proof barrier material, a fluorine-free waterproof and oil-proof paper, and a method for preparing the same. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Paper is a bio-based, recyclable, and biodegradable cellulose material that can serve as an alternative to single-use plastic packaging. However, the hydroxyl groups in the fiber structure and the porosity of the fibers make paper hydrophilic, resulting in poor barrier properties against media such as water and oil, thus limiting its applications. Improving the barrier properties of paper-based materials has become a key factor in the application of paper-based packaging materials.

[0004] Fluorinated compounds and petroleum-based polymers can give paper excellent water and oil repellency, but their use is restricted due to the pollution risks they pose to human health and ecosystems. Conventional polysiloxanes (such as polydimethylsiloxane) have some hydrophobicity, but cannot effectively block greases with low surface tension. Among existing fluorine-free waterproofing agents, organosilicon-based agents typically only provide waterproofing and cannot simultaneously achieve oil repellency, limiting their application in food packaging, greaseproof paper, and other fields. Furthermore, most polysiloxanes have inactive or monofunctional structures, lacking active groups that can chemically bond with the hydroxyl groups on the paper fiber surface. The coating mainly relies on physical adsorption or weak hydrogen bonding, resulting in poor interfacial adhesion and a rapid decline in barrier performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a fluorine-free waterproof and oil-resistant barrier material, a fluorine-free waterproof and oil-resistant paper, and a method for preparing the same. The invention comprises epoxy silicone oil modified with two silane coupling agents and chitosan. The fluorine-free waterproof and oil-resistant barrier material obtained by combining the two can improve the mechanical strength and liquid resistance of paper-based materials.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: Firstly, a fluorine-free waterproof and oil-resistant barrier material comprises component A and liquid B in a mass ratio of (5~8):(2~5); wherein liquid B is a chitosan solution with a mass fraction of 1~3wt%; component A is... , 1≤m≤15, 5≤n≤100.

[0007] Secondly, the preparation method of the above-mentioned fluorine-free waterproof and oil-proof barrier material includes the following steps: A silane coupling agent KH-550 with a mass ratio of (10~25):20 and epoxy silicone oil were added to a solvent, and an epoxy ring-opening reaction was carried out at 30~40℃. Then, a silane coupling agent KH-570 with a mass ratio of (5~7):20 to epoxy silicone oil was added, along with water and a catalyst. A hydrolysis-condensation reaction was carried out at 35~60℃ to obtain component A. Prepare a chitosan solution with a mass fraction of 1-3 wt%, designated as solution B; Component A and liquid B are mechanically mixed in a set ratio to obtain the fluorine-free waterproof and oil-proof barrier material.

[0008] Thirdly, a method for preparing fluorine-free waterproof and oil-proof paper includes the following steps: The above-mentioned fluorine-free waterproof and oil-proof barrier material is coated on the surface of the paper-based material and cured by heating at 50~70℃ for 0.3~0.7h.

[0009] Fourthly, the fluorine-free waterproof and oil-proof paper prepared by the above-mentioned method is a fluorine-free waterproof and oil-proof paper.

[0010] The beneficial effects of this invention are as follows: This invention utilizes two silane coupling agents to modify epoxy silicone oil, which is then compounded with chitosan solution to obtain a fluorine-free, waterproof, and oil-repellent barrier material. In component A, the introduction of amino groups significantly enhances the reactivity and functional tunability of the organosilicon polymer. The grafted 3-methacryloyloxypropyltrimethoxysilane can form a cross-linked network, significantly enhancing cohesive strength and interfacial bonding, resulting in excellent waterproof and oil-repellent properties. The addition of chitosan improves its film-forming properties, obtaining a low surface energy film on paper surfaces, exhibiting excellent waterproof, oil-repellent, and environmentally friendly barrier properties. Attached Figure Description

[0011] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0012] Figure 1 A comparison of the FTIR curves of the novel fluorine-free modified organosilicon waterproofing agent and the epoxy silicone oil raw material used in Example 1.

[0013] Figure 2 This is a comparison chart of the FTIR curves of paper-based waterproof and oil-resistant materials and paper-based raw materials in an example. Figure 3 The images are XPS spectra of the paper-based material raw materials, where (a) is the C1s element spectrum and (b) is the O1s element spectrum.

[0014] Figure 4The XPS spectra of the paper-based waterproof and oil-resistant material in the example are shown, where (a) is the C1s element spectrum, (b) is the N1s element spectrum, (c) is the O1s element spectrum, and (d) is the Si2p element spectrum. Detailed Implementation

[0015] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] The chemical substances involved in the following specific embodiments include: γ-aminopropyltriethoxysilane, also known as 3-aminopropyltriethoxysilane or silane coupling agent KH-550; CAS number 919-30-2.

[0018] 3-Methacryloyloxypropyltrimethoxysilane, also known as silane coupling agent KH-570, has the CAS number 2530-85-0.

[0019] Dibutyltin dilaurate, CAS number 77-58-7.

[0020] Epoxy silicone oil, also known as epoxy-modified silicone oil, is a novel organosilicon material grafted from polymethylsiloxane and epoxy-based alkanes. It was purchased from Shandong Dayi Chemical Co., Ltd., product number DY-E701, and its molecular structure is as follows: , 1≤m≤15, 5≤n≤100.

[0021] One or more embodiments of the present invention provide a fluorine-free waterproof and oil-resistant barrier material, comprising component A and liquid B in a mass ratio of (5~8):(2~5); wherein liquid B is a chitosan solution with a mass fraction of 1~3wt%; component A is: , 1≤m≤15, 5≤n≤100.

[0022] The siloxane backbone endows it with excellent waterproofing ability, the introduction of amino groups greatly enhances the reactivity and functional tunability of the organosilicon polymer, strengthens its adhesion to the paper surface, and the Si-O-Si cross-linking network provides the structural basis for building a complete and dense barrier.

[0023] Liquid B is used to enhance the film-forming properties of component A, resisting the penetration of moisture and oil. The entire fluorine-free waterproof and oil-resistant barrier material uses easily degradable substances as its main raw materials and is fluorine-free, making it environmentally friendly.

[0024] According to one or more embodiments of the present invention, the preparation method of the above-mentioned fluorine-free waterproof and oil-resistant barrier material includes the following steps: A silane coupling agent KH-550 with a mass ratio of (10~25):20 and epoxy silicone oil were added to a solvent, and an epoxy ring-opening reaction was carried out at 30~40℃. Then, a silane coupling agent KH-570 with a mass ratio of (5~7):20 to epoxy silicone oil was added, along with water and a catalyst. A hydrolysis-condensation reaction was carried out at 35~60℃ to obtain component A. Prepare a chitosan solution with a mass fraction of 1-3 wt%, designated as solution B; Component A and liquid B are mechanically mixed in a set ratio to obtain the fluorine-free waterproof and oil-proof barrier material.

[0025] In the above preparation methods, the modified silica sol waterproofing agent prepared by the sol-gel method improves the material compatibility of polysiloxanes. When combined with chitosan solution, it constructs a waterproof and oil-resistant barrier coating. The two work synergistically to enhance the barrier properties of paper. When coated on paper, it forms a protective layer with good film-forming properties, resisting the penetration of moisture and oil. The preparation process of component A is simple, with mild reaction conditions, making it suitable for large-scale applications. Component A and solution B employ a simple physical mixing process; the preparation method is simple, efficient, practical, and easy to promote.

[0026] Optionally, the epoxy silicone oil has the following structural formula: , 1≤m≤15, 5≤n≤100.

[0027] Optionally, the solvent is anhydrous ethanol or isopropanol; the mass-volume ratio of epoxy silicone oil to solvent is 0.25~0.5g / mL; it has good solubility and high volatility, and is easy to evaporate and remove during the process, reducing residues.

[0028] Optionally, water is added to the hydrolysis-condensation reaction, wherein the amount of water added is 5-6 wt% of the epoxy silicone oil, so that the system has the conditions for hydrolysis and provides hydrolysis reactants.

[0029] Optionally, the catalyst for the hydrolysis-condensation reaction is dibutyltin dilaurate; the ratio of the catalyst volume to the mass of the epoxy silicone oil is (15~20) μL: 20g, which accelerates the hydrolysis and condensation.

[0030] Optionally, after the hydrolysis-condensation reaction is completed, the solvent and impurities are removed by vacuum distillation. The parameters of the vacuum distillation are: vacuum degree: -0.10~-0.08MPa; temperature: 35~40℃; distillation rate: 1~2 drops / second.

[0031] Optionally, in the preparation method of solution B, the solvent is an aqueous solution of acetic acid with a mass fraction of 0.5~1.5wt%, which is used to promote the dissolution of chitosan.

[0032] One or more embodiments of the present invention disclose a method for preparing fluorine-free waterproof and oil-resistant paper, comprising the following steps: The above-mentioned fluorine-free waterproof and oil-proof barrier material is coated on the surface of the paper-based material and cured by heating at 50~70℃ for 0.3~0.7h.

[0033] Component A and liquid B work synergistically to enhance the barrier properties of paper. When coated on paper, they form a protective film with good film-forming properties that can resist the penetration of moisture and oil.

[0034] Optionally, the coating amount of the fluorine-free waterproof and oil-resistant barrier material on the paper-based material surface is 9%. 10g / m 2 Because liquid B improves its film-forming properties, it can greatly reduce its consumption on the surface of paper-based materials, and a single layer coating can achieve effective waterproof and oil-proof effects.

[0035] According to one or more embodiments of the present invention, the fluorine-free waterproof and oil-proof paper prepared by the above-described method for preparing fluorine-free waterproof and oil-proof paper is a fluorine-free waterproof and oil-proof paper.

[0036] The present invention will be further described below with reference to specific embodiments.

[0037] Preparation Example 1 Using a three-necked flask as the reaction vessel, 60 mL of anhydrous ethanol was added, followed by 11.8 g of silane coupling agent KH-550, and the mixture was stirred until homogeneous. The mixture was heated to 35°C in a water bath, and 20 g of epoxy silicone oil was added dropwise. The reaction system was then stirred continuously at 35°C for 30 min. Acetic acid was added to adjust the pH to 6.5, and the mixture was stirred and kept at this temperature for 1 h. Then, 1.2 g of deionized water was added while stirring to prepare the system for hydrolysis. Subsequently, 5 g of silane coupling agent KH-570 was slowly added dropwise, along with 20 µL of dibutyltin dilaurate as a catalyst. The mixture was stirred continuously at 35°C for 7 h. Finally, the reaction product was purified in a distillation flask using a rotary vacuum distillation apparatus at a vacuum level of -0.09 MPa, a temperature of 35-40°C, and a distillation rate of 1-2 drops / second to remove the solvent and insoluble impurities, yielding component A of the novel waterproofing agent.

[0038] The epoxy silicone oil structure in this embodiment is shown below: , 1≤m≤15, 5≤n≤100.

[0039] Component A was obtained by modifying epoxy silicone oil with silane coupling agents KH-550 and KH-570 sequentially. KH-550 reacted with epoxy silicone oil in a solvent to undergo an epoxy ring-opening reaction, yielding a branched-chain modified organosilicon precursor containing β-hydroxy secondary amine groups (-CH(OH)-CH2-NH-) in its side chains. The introduction of amino groups significantly enhanced the reactivity and functional tunability of the organosilicon polymer. The structure of the obtained intermediate product is shown below: , 1≤m≤15, 5≤n≤100.

[0040] Then, 3-methacryloyloxypropyltrimethoxysilane was grafted onto the precursor side chains via a hydrolysis-condensation reaction to form a Si-O-Si structure, creating a cross-linked network that significantly enhanced cohesive strength and interfacial bonding. The resulting structure is shown below: , 1≤m≤15, 5≤n≤100.

[0041] Comparing the FTIR curves of the epoxy silicone oil raw material and the finally obtained fluorine-free modified organosilicon waterproofing agent, such as... Figure 1 As shown, the product in this embodiment is 2964 cm. -1 The asymmetric stretching vibration peak of the methyl group weakens or even disappears, while the peak at 915 cm⁻¹ is also reduced. -1The weakening of the COC symmetric stretching vibration peak indicates that the amino group of γ-aminopropyltriethoxysilane underwent a ring-opening reaction with the epoxy group of epoxy silicone oil. Under weakly acidic conditions, the silanol groups generated from the hydrolysis of 3-methacryloyloxypropyltrimethoxysilane will undergo a condensation reaction with the Si-H bond to form a Si-O-Si bond, hence the peak at 2156 cm⁻¹. -1 and 1264 cm -1 The stretching vibrations of the Si-H bonds and the symmetric deformation vibrations of Si-CH3 at 1720 cm⁻¹ are weakened, and at 1720 cm⁻¹... -1 The new C=O peak at 1092 cm⁻¹ further confirms that 3-methacryloyloxypropyltrimethoxysilane was successfully grafted onto the branched chain of organosilicon; and the peak at 1092 cm⁻¹ further confirms that 3-methacryloyloxypropyltrimethoxysilane was successfully grafted onto the branched chain of organosilicon. -1 and 1026cm -1 The asymmetric stretching vibration peak of Si-O-Si shown at the position is significantly shifted and strengthened compared to the peak of epoxy silicone oil raw material in this segment, indicating that the novel modified organosilicon has formed a network structure.

[0042] Example 1 A fluorine-free waterproof and oil-proof barrier material comprises component A and liquid B in a mass ratio of 8:2. Component A is prepared by preparation example 1, and liquid B is a chitosan solution with a mass fraction of 2 wt%.

[0043] Preparation methods include: 2g of chitosan powder was dispersed in a beaker containing 1wt% acetic acid aqueous solution. The beaker was then placed in a constant temperature water bath magnetic stirrer and stirred and dissolved for 3h under water bath heating at 70℃ to prepare a homogeneous B solution (100g) with a mass fraction of 2% w / w. Component A and liquid B are mixed evenly by physical means to obtain a fluorine-free waterproof and oil-proof barrier material.

[0044] A fluorine-free waterproof and oil-proof paper, the preparation method of which includes: The base paper used has a basis weight of 225 g / m³. 2 The white, thick paper was tested for oil resistance using the surface repulsion method according to GB / T22805.2-2008 standard, and the oil resistance rating was 0. Water absorption was measured using a Cobb absorbency tester according to GB / T1540-2002 standard, and the Cobb 600 rating was 85.83 g / m³. 2 According to GB / T1037-2021 standard, the water vapor transmission rate is 1805.25 g / m³. 2• 24h; measured according to ISO / TS 14778:2021 standard, the water contact angle is 84.2° and the oil contact angle is 29.4°; the tensile strength is 1.53KN / m and the elongation at break is 1.92% according to GB / T12914-2018 standard; the longitudinal and transverse tear strengths are 224.35 mN and 225.81 mN respectively according to GB / T455-2002 standard; the longitudinal and transverse flexural endurance are 14 times and 11 times respectively according to GB / T457-2008 standard.

[0045] The fluorine-free waterproof and oil-resistant barrier material obtained in this embodiment is prepared according to 9.78 g / m³. 2 The coating amount is applied to the base paper, and then heated and cured at 60℃ for 0.5h to obtain fluorine-free waterproof and oil-proof paper.

[0046] The resulting waterproof and oil-resistant paper has a water contact angle of 124.6°, an oil contact angle of 58.3°, and a Cobb 600 content of 6.62 g / m². 2 It has an oil resistance rating of 9 and a water vapor transmission rate of 773.58 g / m². 2 • After 24 hours, the tensile strength was 1.64 KN / m, the elongation at break was 2.01%, the longitudinal and transverse tear strengths were 262.29 mN and 227.27 mN, respectively, and the longitudinal and transverse flexural strengths were 23 and 18 times, respectively.

[0047] Example 2 A fluorine-free waterproof and oil-proof barrier material comprises component A and liquid B in a mass ratio of 7:3. The requirements for each raw material and the preparation method are the same as in Example 1.

[0048] A fluorine-free waterproof and oil-resistant paper, using the same base paper as in Example 1, with a density of 10.1 g / m³. 2 The coating amount was prepared, and other preparation methods were the same as in Example 1.

[0049] The resulting waterproof and oil-resistant paper has a water contact angle of 123.5°, an oil contact angle of 59.2°, and a Cobb 600 content of 8.41 g / m². 2 It has an oil resistance rating of 10 and a water vapor transmission rate of 746.28 g / m². 2 After 24 hours, the tensile strength was 1.67 KN / m, the elongation at break was 1.96%, the longitudinal and transverse tear strengths were 250.62 mN and 227.28 mN, respectively, and the longitudinal and transverse flexural strengths were 19 and 17 times, respectively.

[0050] Example 3 A fluorine-free waterproof and oil-proof barrier material comprises component A and liquid B in a mass ratio of 6:4. The requirements for each raw material and the preparation method are the same as in Example 1.

[0051] A fluorine-free waterproof and oil-resistant paper, using the same base paper as in Example 1, with a density of 9.94 g / m³. 2 The coating amount was prepared, and other preparation methods were the same as in Example 1.

[0052] The resulting waterproof and oil-resistant paper has a water contact angle of 120°, an oil contact angle of 61.7°, and a Cobb 600 content of 9.8 g / m². 2 It has an oil resistance rating of 11 and a water vapor transmission rate of 817.79 g / m³. 2 After 24 hours, the tensile strength was 1.70 kN / m, the elongation at break was 1.94%, the longitudinal and transverse tear strengths were 249.16 mN and 218.51 mN, respectively, and the longitudinal and transverse flexural strengths were 19 and 14 times, respectively.

[0053] Example 4 A fluorine-free waterproof and oil-proof barrier material comprises component A and liquid B in a mass ratio of 5:4. The requirements for each raw material and the preparation method are the same as in Example 1.

[0054] A fluorine-free waterproof and oil-resistant paper, using the same base paper as in Example 1, with a density of 9.98 g / m³. 2 The coating amount was prepared, and other preparation methods were the same as in Example 1.

[0055] The resulting waterproof and oil-resistant paper has a water contact angle of 118°, an oil contact angle of 60.3°, and a Cobb 600 content of 13.6 g / m³. 2 It has an oil resistance rating of 11 and a water vapor transmission rate of 996.39 g / m². 2 After 24 hours, the tensile strength was 1.72 kN / m, the elongation at break was 1.78%, the longitudinal and transverse tear strengths were 224.35 mN and 199.54 mN, respectively, and the longitudinal and transverse flexural strengths were 18 and 13 times, respectively.

[0056] The FTIR spectra of the paper-based waterproof and oil-resistant material (waterproof paper) prepared by the comparative example and the paper-based material raw material (base paper) are shown below. Figure 2 As shown, the base paper is approximately 3317 cm². -1 The OH stretching vibration peak at 2883 cm⁻¹ -1 and 1022 cm -1 The strong absorption peaks nearby correspond to the CH stretching vibration and the COC glycosidic bond vibration, respectively, reflecting the polysaccharide structure of the substrate. The waterproof and oil-resistant paper exhibits absorption peaks at approximately 1725 cm⁻¹. -1 (ester group C=O) and 1562 cm -1 The (NH bending) peaks coexist, representing the ester groups of the waterproofing agent and the amino groups of chitosan, respectively; 1005 cm⁻¹ -1 The nearby broad and strong absorption band is a superposition of Si-O-Si vibrations and polysaccharide COC vibrations, at 1251 cm⁻¹. -1The Si-CH3 peaks are still prominent, indicating that the organosilicon network and polysaccharide chains coexist in the composite coating, further demonstrating the stability of the coating.

[0057] XPS elemental spectra of the paper-based waterproof and oil-resistant material (waterproof paper) prepared by the comparative example and the paper-based material raw material (base paper) are shown below. Figure 3 and Figure 4 As shown, carbon on the surface of the base paper exists mainly in two chemical states. The CC / CH peak at 284.80 eV is typically attributed to aliphatic or aromatic carbon in paper, which is the main carbon component of plant fiber materials. The CO peak (532.75 eV) mainly corresponds to the abundant hydroxyl groups and oxygen-containing functional groups such as ether bonds in cellulose and hemicellulose, further confirming the characteristic that the paper is mainly composed of carbohydrates. Looking at the intensity of these two peaks, the intensity of the CO peak in the C1s spectrum of uncoated paper is generally significantly higher than that of the CC / CH peak, indicating that the paper surface is rich in oxygen-containing functional groups and has high hydrophilicity and chemical activity. This also provides possible active sites for the adhesion of subsequent coatings. In addition to the inherent CC / CH peak of the substrate, the surface of the waterproof and oil-resistant paper shows a new CN peak at 285.95 eV and a C=O / NC=O peak at 288.61 eV, which correspond to the amino group of chitosan and the nitrogen-containing carbonyl group structure possibly originating from the amidation reaction, respectively. The signal at 399.57 eV in the N1s spectrum further confirms that nitrogen coexists in the form of amino and amide groups. The distinct silicon characteristic peak at 101.78 eV in the Si2p spectrum indicates the successful introduction of the siloxane network. The signals at 531.70 eV and 532.49 eV in the O1s spectrum suggest that Si-OC bonds or strong hydrogen bonds may have formed between the siloxane and cellulose or chitosan. The composite coating forms an inorganic-organic hybrid interface on the paper surface, possessing both CS active groups and a hydrophobic framework. The two components not only retain their respective characteristic functional groups but may also form a more stable coating structure through chemical or physical interactions between amino groups and silane groups or hydroxyl groups.

[0058] Comparative Example 1 Using component A obtained in Preparation Example 1 as the barrier material, and employing the same base paper as in Example 1, at a concentration of 8.64 g / m²... 2 After applying the coating, the paper is cured at 60°C for 0.5 hours to obtain waterproof paper.

[0059] The resulting waterproof paper has a water contact angle of 125°, an oil contact angle of 34.1°, and a Cobb 600 content of 12.4 g / m². 2 It has an oil resistance rating of level 2 and a water vapor transmission rate of 703.81 g / m². 2After 24 hours, the tensile strength was 1.63 KN / m, the elongation at break was 2.03%, the longitudinal and transverse tear strengths were 271.04 mN and 234.56 mN, respectively, and the longitudinal and transverse flexural strengths were 24 and 20 times, respectively.

[0060] It can be seen that without the addition of solution B, when the barrier material is applied to the paper surface, it is difficult to form a dense film on the paper surface, resulting in a decrease in the paper's oil resistance and tensile strength.

[0061] Comparative Example 2 Using liquid B from Example 1 as the barrier material, and employing the same base paper as in Example 1, at a concentration of 4.52 g / m²... 2 After coating with the specified amount, the paper is cured at 60℃ for 0.5 hours to obtain greaseproof paper.

[0062] The resulting oil-resistant paper had a water contact angle of 86.7°, an oil contact angle of 34.1°, and a Cobb 600 content of 59 g / m². 2 It has an oil resistance rating of 4 and a water vapor transmission rate of 1672.13 g / m². 2 After 24 hours, the tensile strength was 1.89 kN / m, the elongation at break was 1.87%, the longitudinal and transverse tear strengths were 219.97 mN and 187.16 mN, respectively, and the longitudinal and transverse flexural strengths were 11 and 9 times, respectively.

[0063] It can be seen that without the addition of liquid A, when the barrier material is applied to the paper surface, it is difficult to form a low surface energy coating on the paper surface, resulting in a decrease in the paper's hydrophobic properties and a decrease in the overall waterproof and oil-proof performance of the paper.

[0064] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fluorine-free waterproof and oil-proof barrier material, characterized in that, It includes component A and solution B in a mass ratio of (5~8):(2~5); wherein solution B is a chitosan solution with a mass fraction of 1~3wt%; component A is... ,1≤m≤15,5≤n≤100。 2. A method for preparing a fluorine-free waterproof and oil-resistant barrier material as described in claim 1, characterized in that, Including the following steps: A silane coupling agent KH-550 with a mass ratio of (10~25):20 and epoxy silicone oil were added to a solvent, and an epoxy ring-opening reaction was carried out at 30~40℃. Then, a silane coupling agent KH-570 with a mass ratio of (5~7):20 to epoxy silicone oil was added, along with water and a catalyst. A hydrolysis-condensation reaction was carried out at 35~60℃ to obtain component A. Prepare a chitosan solution with a mass fraction of 1-3 wt%, designated as solution B; Component A and liquid B are mechanically mixed in a set ratio to obtain the fluorine-free waterproof and oil-proof barrier material.

3. The preparation method of the fluorine-free waterproof and oil-proof barrier material as described in claim 2, characterized in that, The molecular structure of the epoxy silicone oil is as follows: ,1≤m≤15,5≤n≤100。 4. The preparation method of the fluorine-free waterproof and oil-proof barrier material as described in claim 2, characterized in that, The solvent is anhydrous ethanol or isopropanol; the mass-to-volume ratio of epoxy silicone oil to solvent is 0.25~0.5 g / mL.

5. The preparation method of the fluorine-free waterproof and oil-proof barrier material as described in claim 2, characterized in that, Water is added during the hydrolysis-condensation reaction, and the amount of water added is 5-6 wt% of the epoxy silicone oil.

6. The method for preparing the fluorine-free waterproof and oil-resistant barrier material as described in claim 2, characterized in that, The catalyst for the hydrolysis-condensation reaction is dibutyltin dilaurate; the ratio of the catalyst volume to the mass of the epoxy silicone oil is (15~20) μL: 20g.

7. The preparation method of the fluorine-free waterproof and oil-proof barrier material as described in claim 2, characterized in that, In the preparation method of solution B, the solvent is an aqueous solution of acetic acid with a mass fraction of 0.5~1.5wt%.

8. A method for preparing fluorine-free waterproof and oil-proof paper, characterized in that, Includes the following steps: The fluorine-free waterproof and oil-proof barrier material described in claim 1 is coated onto the surface of a paper-based material and cured by heating at 50~70℃ for 0.5 h. Component A and liquid B work synergistically to enhance the barrier properties of paper. When coated on paper, they form a protective film with good film-forming properties that can resist the penetration of moisture and oil.

9. The method for preparing fluorine-free waterproof and oil-proof paper as described in claim 8, characterized in that, The coating amount of the fluorine-free waterproof and oil-proof barrier material on the paper-based material surface is 9%. 10g / m 2 .

10. A fluorine-free waterproof and oil-proof paper prepared by a method according to any one of claims 8-9.

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