A water-proof and easy-to-clean fluorine-free acrylate emulsion, a preparation method and application thereof

Abstract

The application belongs to the technical field of polyacrylate emulsion, and more particularly relates to a fluorine-free polyacrylate emulsion with waterproof and easy-to-clean properties, a preparation method and application thereof. The polyacrylate emulsion is prepared by first synthesizing an amphiphilic polyurethane prepolymer emulsion, then emulsifying acrylate monomers with the polyurethane emulsion and a composite emulsifier as emulsifiers to obtain a pre-emulsion, and finally adding an initiator to initiate polymerization of the acrylate monomers, so as to obtain polyacrylate latex particles with a polyurethane protective colloid shell and a hydrophobic functional component, a crosslinking component and a large steric component as the core. The layered arrangement of the polymers in the emulsion on the substrate endows the substrate with good waterproof and easy-to-clean properties. The preparation method of the polyacrylate emulsion is simple, avoids the use of fluorine-containing monomers, is suitable for industrial production, has both waterproof and easy-to-clean properties, and is suitable for waterproof and easy-to-clean finishing of various fabrics such as chemical fibers, nylon and polyester-cotton.

Description

Technical Field

[0001] This application belongs to the field of polyacrylate emulsion technology, and more specifically, relates to a waterproof and easy-to-clean non-fluorinated acrylate emulsion, its preparation method and application. Background Technology

[0002] With the continuous improvement of people's living standards and the expansion of textile applications, the performance of traditional textiles can no longer meet the higher requirements of people for textile performance and the special performance requirements of various industries and fields. Functional finishing involves treating textiles with special finishing agents to give them properties they did not originally possess. Furthermore, due to increased awareness of environmental protection and personal safety, and the public's strong pursuit of a healthy environment, the advantages of fluorine-free products are gradually becoming more apparent. In daily life, clothing gets stained and dirty; how to efficiently and quickly remove these stains from fabrics, reduce washing water consumption, and improve the cleanliness of clothing is a major market demand. Therefore, combining and recombining multiple functions to construct a safe, environmentally friendly, fluorine-free, waterproof, and easy-to-clean functional finishing system, and developing and designing green and efficient fluorine-free, waterproof, and easy-to-clean finishing agent products, is particularly important and is an inevitable trend in the industry.

[0003] Patent CN116377721A grafts low-surface-energy, fluorine-free water-repellent groups and hydrophilic polyether groups onto the fiber surface via a polyurethane condensation reaction. In a dry state, the water-repellent groups occupy the fiber surface; in water, the hydrophilic polyether segments migrate and flip to the fiber surface, achieving easy stain removal. However, the self-made diol used in this patent is complex to prepare and carries certain risks, making it unsuitable for industrial production. Patent CN116284554A provides a self-dispersing, waterproof, oil-repellent, and easy-to-clean treatment agent for textiles, possessing both water and oil repellency and easy stain removal. However, this additive contains perfluorohexyl ethyl methacrylate polymer, still raising the possibility of environmental pollution from fluorine-containing substances. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a waterproof and easy-to-clean non-fluorinated acrylate emulsion, its preparation method and application, aiming to solve the technical problems of the complex preparation method or fluorine pollution in the prior art.

[0005] To achieve the above objectives, in a first aspect, this application provides a method for preparing a waterproof and easily stain-resistant fluorine-free acrylate emulsion, comprising the following steps: (1) Under a protective atmosphere, the polyurethane prepolymer is diluted with a solvent and mixed with a neutralizing agent, stirred and reacted, then water is added for emulsification, and after removing the solvent, a polyurethane dispersion emulsion is obtained. (2) Dissolve the composite emulsifier in water, mix it with the acrylate monomer and the polyurethane dispersion emulsion described in step (1), heat and stir to emulsify it, and obtain a pre-emulsion; (3) Under heating conditions, the initiator is introduced into the pre-emulsion described in step (2), and the temperature is maintained to allow the acrylate monomers to undergo a polymerization reaction. After the reaction is completed, the temperature is lowered to obtain a waterproof and easy-to-clean fluorine-free acrylate emulsion.

[0006] Preferably, the polyurethane prepolymer in step (1) is obtained by urethane esterification reaction of polyol and isocyanate under the condition of sequential addition of catalyst, chain extender and end capping agent.

[0007] Preferably, the molecular weight of the polyol is 500-1500 g / mol, more preferably 500-1000 g / mol; the polyol is one or more of polyethylene glycol and polypropylene glycol.

[0008] Preferably, the mass ratio of the polyol to the isocyanate is (1~5):1; the neutralizing agent in step (1) is acetic acid and / or hydrochloric acid.

[0009] Preferably, the composite emulsifier in step (2) is a mixture of cationic and nonionic emulsifiers, wherein the cationic emulsifier is one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and dodecyldimethylbenzylammonium chloride; the nonionic emulsifier is one or more of isomeric alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and isomeric secondary alcohol polyoxyethylene ether; the mass ratio of the cationic emulsifier to the nonionic emulsifier is 1:1 to 3:1, and the amount of the composite emulsifier is 5 to 10% of the total mass of the acrylate monomers.

[0010] Preferably, the acrylate monomer in step (2) is a mixture of a hydrophobic acrylate monomer, a crosslinking acrylate monomer, and a sterically hindered acrylate monomer, wherein, The hydrophobic component acrylate monomer is one or more of octadecyl acrylate, octadecyl methacrylate, heptadecanyl acrylate, and hexadecyl acrylate; The crosslinking component acrylate monomer is one or more of glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate; The sterically hindered component acrylate monomer is one or more of isoborneol acrylate and isoborneol methacrylate; The mass ratio of the hydrophobic component acrylate monomer, the crosslinking component acrylate monomer, and the sterically hindered component acrylate monomer is 20:1:1~5.

[0011] Preferably, the mass ratio of the polyurethane dispersion emulsion to the acrylate monomer in step (2) is (0.8~1.2):1, and the solid content of the polyurethane dispersion emulsion is 15-25%.

[0012] According to another aspect of the present invention, a waterproof and easy-to-clean non-fluorinated polyacrylate emulsion prepared by the preparation method described above is provided.

[0013] According to another aspect of the invention, the use of the aforementioned waterproof and stain-resistant non-fluorinated polyacrylate emulsion in the application or preparation of a fabric finishing agent is provided.

[0014] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) The method for preparing the waterproof and easy-to-clean fluorine-free acrylate emulsion provided by the present invention firstly synthesizes an amphiphilic polyurethane prepolymer emulsion, then uses the polyurethane emulsion and a composite emulsifier as emulsifiers to emulsify the acrylate monomers to obtain a preemulsion, and finally adds an initiator to initiate the polymerization of the acrylate monomers to obtain polyacrylate latex particles with polyurethane as a protective colloidal shell and hydrophobic functional components, crosslinking components, and sterically hindered components as the core. The layered arrangement of polymers in the emulsion on the substrate gives the substrate good waterproof and easy-to-clean properties. The polyacrylate emulsion preparation method of the present invention is simple, avoids the use of fluorine-containing monomers, is suitable for industrial production, and has both waterproof and easy-to-clean functions, making it suitable for waterproof and easy-to-clean finishing of various fabrics such as chemical fibers, nylon, and polyester-cotton blends.

[0015] (2) The polyacrylate emulsion of the present invention uses polyurethane as a protective colloidal shell and polyacrylate latex particles with hydrophobic functional components, crosslinking components, and sterically hindered components as the core, thereby achieving the directional migration of functional monomers and the directional arrangement of hydrophilic / hydrophobic microregions. In the film-forming stage of polymer latex particles, the polyurethane structure plays the role of emulsifying hydrophobic monomers, fixing hydrophobic microregions, and promoting chain segment inversion, while the polyacrylate structure plays the role of fixing the qualitative arrangement of chain segments, increasing adhesion to the substrate, and enhancing the crystallization of hydrophobic functional microregions. The layered arrangement of polymers on the substrate gives the substrate better waterproof and easy-to-clean properties.

[0016] (3) In the acrylate emulsion synthesized in this invention, the amphiphilic polyurethane and the hydrophobic polyacrylate polymer are not on the same polymer chain, nor are they a simple physical blend. Instead, they coexist stably with a specific core-shell structure, so they do not affect each other. At the same time, the polyurethane segments and the polyacrylate waterproof functional components enhance the bonding between the waterproof functional components and the fabric through the entanglement of the segments. The physical entanglement does not affect the conformational change of the hydrophilic segments. Thus, excellent waterproof and easy-to-clean functions are achieved in the same acrylate emulsion.

[0017] (4) Small molecule emulsifiers are also hydrophilic, and excessive amounts can significantly reduce the waterproof performance of the emulsion. The polyurethane dispersion emulsion of this invention can act as a co-emulsifier during the polymerization and emulsification of acrylate monomers, thus reducing the amount of small molecule emulsifiers used. The polyurethane dispersion of this invention, acting as a co-emulsifier, also avoids the decrease in waterproof performance caused by excessive use of small molecule emulsifiers to a certain extent, balancing waterproof and easy-to-clean properties. Attached Figure Description

[0018] Figure 1 This is an electron microscope photograph of the final sample obtained in Example 3 of this application; Figure 2 This is a photograph of an easily soiled fabric sample arranged according to Embodiment 3 of this application; Figure 3 These are optical microscope photographs of the wetted and waterproof fabrics represented by Comparative Examples 2 and 3 of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] The present invention provides a method for preparing a waterproof and easy-to-clean non-fluorinated acrylate emulsion, comprising the following steps: (1) Under a protective atmosphere, the polyurethane prepolymer is diluted with a solvent and mixed with a neutralizing agent, stirred and reacted, then water is added for emulsification, and after removing the solvent, a polyurethane dispersion emulsion is obtained. (2) Dissolve the composite emulsifier in water, mix it with the acrylate monomer and the polyurethane dispersion emulsion described in step (1), heat and stir to emulsify it, and obtain a pre-emulsion; (3) Under heating conditions, the initiator is introduced into the pre-emulsion described in step (2), and the reaction is kept at a constant temperature for several hours to allow the acrylate monomers to undergo a polymerization reaction. After the reaction is completed, the temperature is lowered to obtain a waterproof and easy-to-clean fluorine-free acrylate emulsion.

[0021] The polyurethane prepolymer in step (1) is obtained by urethane esterification reaction of polyol and isocyanate under conditions of sequential addition of catalyst, chain extender and end-capping agent. In some embodiments, the preparation method of the polyurethane prepolymer in step (1) includes the following steps: after mixing the dehydrated polyol and isocyanate, reacting at 55~65℃ for 1.5~2.5h, adding catalyst, and continuing the reaction at the temperature for 1.5~2.5h; cooling to 40~55℃, adding chain extender, and reacting at the temperature for 1~1.5h; adding end-capping agent, and reacting at the temperature for 1~1.5h to obtain polyurethane prepolymer.

[0022] In some embodiments, the molecular weight of the polyol is 500-1500 g / mol, more preferably 500-1000 g / mol, and most preferably 500-800 g / mol. The polyol is one or more of polyethylene glycol (PEG) and polypropylene glycol.

[0023] In some embodiments, the isocyanate is one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate; the catalyst is one or more of stannous octoate, dibutyltin dilaurate, and bismuth isooctanoate; the chain extender is one or more of N-methyldiethanolamine, N-ethyldiethanolamine, and N,N-dihydroxyethylpiperazine; the end-capping agent is one or more of 3,5-dimethylpyrazole, butanone oxime, and caprolactam; and the neutralizing agent in step (1) is acetic acid and / or hydrochloric acid.

[0024] In some embodiments, the mass ratio of the polyol to the isocyanate is (1~5):1.

[0025] In some embodiments, the solvent in step (1) is one or more of acetone, butanone, and N,N-dimethylformamide.

[0026] In some embodiments, step (1) specifically involves: cooling the polyurethane prepolymer to 40-50°C, diluting it with acetone solvent, adding a neutralizing agent, stirring and reacting for 0.5-1 h, emulsifying with water for 0.5-1 h, removing the acetone solvent, and obtaining the polyurethane dispersion emulsion.

[0027] In some embodiments, the composite emulsifier in step (2) is a mixture of cationic and nonionic emulsifiers, wherein the cationic emulsifier is one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and dodecyldimethylbenzylammonium chloride; the nonionic emulsifier is one or more of isomeric alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and isomeric secondary alcohol polyoxyethylene ether; the mass ratio of the cationic emulsifier to the nonionic emulsifier is 1:1 to 3:1, and the amount of the composite emulsifier is 5 to 10% of the total mass of the acrylate monomers.

[0028] In some embodiments, the acrylate monomer in step (2) is a mixture of a hydrophobic acrylate monomer, a crosslinking acrylate monomer, and a sterically hindered acrylate monomer, wherein, The hydrophobic component acrylate monomer is one or more of octadecyl acrylate, octadecyl methacrylate, heptadecanyl acrylate, and hexadecyl acrylate; The crosslinking component acrylate monomer is one or more of glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate; The sterically hindered component acrylate monomer is one or more of isoborneol acrylate and isoborneol methacrylate; The mass ratio of the hydrophobic component acrylate monomer, the crosslinking component acrylate monomer, and the sterically hindered component acrylate monomer is 20:1:1~5.

[0029] In some embodiments, the initiator in step (3) is one or more of azobisisobutyramidine hydrochloride, ammonium persulfate and potassium persulfate, and the amount of the initiator is 1 to 2% of the total mass of the acrylate monomers.

[0030] In some embodiments, the mass ratio of the polyurethane dispersion emulsion to the acrylate monomer in step (2) is (0.8~1.2):1, and the solid content of the polyurethane dispersion emulsion is 15-25%. The heating and stirring are performed at 50~60℃ for 10~20 min and ultrasonication for 20~40 min.

[0031] In some embodiments, step (3) specifically involves: adding the initiator to the pre-emulsion at 60-85°C under a nitrogen atmosphere and maintaining the temperature for 3-5 hours; after the reaction is completed, cooling to below 45°C, filtering and discharging to obtain the waterproof and easy-to-clean fluorine-free polyacrylate emulsion.

[0032] The waterproof and stain-resistant non-fluorinated polyacrylate emulsion prepared by this invention can be used as or used to prepare fabric finishing agents.

[0033] For acrylic emulsions used in fabric finishing, the waterproof function of the emulsion is usually achieved by introducing hydrophobic alkyl long chains. However, to achieve the easy-to-clean function of the emulsion, hydrophilic alkyl segments need to be introduced. Therefore, if the two alkyl segments are simply mixed to prepare the emulsion, the waterproof performance of the emulsion is usually severely affected. Therefore, there is usually a contradiction in simultaneously improving the waterproof and easy-to-clean properties of the emulsion according to the traditional approach. Based on this, the present invention proposes a method for preparing a waterproof and easy-to-clean fluorine-free acrylic emulsion. First, by controlling the appropriate molecular weight of PEG, an amphiphilic polyurethane prepolymer emulsion is synthesized. Then, the polyurethane prepolymer emulsion and a composite emulsifier are used together as emulsifiers to emulsify the acrylic monomers to obtain a preemulsion. The acrylic monomers include hydrophobic acrylic monomers, crosslinking acrylic monomers, and sterically hindered acrylic monomers. Finally, an initiator is added to initiate polymerization to obtain polyacrylate latex particles with polyurethane as a protective colloidal shell and hydrophobic functional components, crosslinking components, and sterically hindered components as the core. The polyurethane prepolymer emulsion synthesized in this invention can act as a co-emulsifier to emulsify the hydrophobic monomers of acrylates. The polyurethane structure provides easy stain removal, while the polyacrylate portion provides waterproofing. The core-shell two-phase design reduces the mutual interference between their respective functions.

[0034] The amphiphilic polyurethane dispersion in the acrylate emulsion of this invention has multiple functions. On the one hand, it can act as a co-emulsifier to emulsify acrylate monomers, encapsulate hydrophobic functional monomers, reduce the amount of small molecule composite emulsifiers used, and synergistically improve waterproof performance. On the other hand, the amphiphilic polyurethane prepolymer emulsion contains highly polar urethane groups, which can easily combine with the substrate through physical interaction and have a good anchoring effect with the substrate. After being applied to the fabric, the polyurethane component contacts the substrate, while the hydrophobic component in the core migrates to the fabric surface, so that the hydrophilic polyurethane component does not affect the waterproof performance of the fabric. During the washing process, the chain segments of the polyurethane hydrophilic component in contact with the substrate will flip and extend, thereby removing stains and achieving an easy stain removal effect.

[0035] The waterproof, easy-to-clean, fluorine-free acrylate emulsion prepared by this invention has a hydrophilic segment of amphiphilic polyurethane located on the outer layer of the core-shell structure, while the hydrophobic polyacrylate is located inside the core. When the particles are stacked to form a film, the outermost polyurethane component will be anchored to the fabric structure. However, as the latex particles become unstable in the high-temperature setting environment, the hydrophobic component inside the core flips to the outermost layer, resulting in a directional arrangement of hydrophilic and hydrophobic micro-regions.

[0036] This invention relates to a polyacrylate emulsion with a polyurethane protective colloidal shell and a core of hydrophobic functional components, crosslinking components, and sterically hindered acrylate monomers. It regulates the directional migration of functional monomers and the directional arrangement of hydrophilic / hydrophobic microdomains. During the polymer latex particle film-forming stage, the polyurethane structure emulsifies the hydrophobic monomers, fixes the hydrophobic microdomains, and promotes chain segment inversion, while the polyacrylate structure fixes the qualitative arrangement of chain segments, increases adhesion to the substrate, and enhances the crystallization of the hydrophobic functional microdomains. The layered arrangement of the polymer on the substrate imparts good waterproof and easy-to-clean properties to the substrate. The polyacrylate emulsion preparation method of this invention is simple, avoids the use of fluorinated monomers, is suitable for industrial production, and combines waterproof and easy-to-clean functions, making it suitable for waterproof and easy-to-clean finishing of various fabrics such as chemical fibers, nylon, and polyester-cotton blends.

[0037] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0038] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0039] The process parameters in the following examples, unless otherwise specified, are generally performed under conventional conditions.

[0040] The embodiments of this application are described below with reference to the accompanying drawings.

[0041] Example 1 (1) Preparation reaction of polyurethane dispersion Under a nitrogen atmosphere, 30.0 g of polyethylene glycol 600 and 13.1 g of toluene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted with stirring at 60 °C for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 1.8 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 1.92 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, 20 g of acetone was added for dilution, and 0.9 g of acetic acid was added for neutralization. The reaction was stirred for 0.5 h. 190.9 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove the acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0042] (2) Preparation reaction of polyacrylate emulsion 1.5 g of octadecyltrimethylammonium chloride and 0.5 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl acrylate, 1.0 g of glycidyl methacrylate, 4.0 g of isobornyl methacrylate, and 25.0 g of the polyurethane dispersion emulsion from step (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was complete, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0043] Example 2 (1) Preparation reaction of polyurethane dispersion emulsion Under a nitrogen atmosphere, 50.0 g of polyethylene glycol 600 and 12.6 g of hexamethylene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted with stirring at 60 °C for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 1.8 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 1.92 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, diluted, and neutralized with 0.9 g of acetic acid. The reaction was stirred for 0.5 h. 268.9 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0044] (2) Preparation reaction of polyacrylate emulsion 3.0 g of octadecyltrimethylammonium chloride and 1.0 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 160.0 g of deionized water. 40.0 g of octadecyl acrylate, 2.0 g of glycidyl methacrylate, 8.0 g of isobornyl methacrylate, and 50.0 g of the polyurethane dispersion emulsion from step (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 1.0 g of azobisisobutyramidine hydrochloride was dissolved in 60 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was complete, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0045] Example 3 (1) Preparation reaction of polyurethane dispersion emulsion Under a nitrogen atmosphere, 60.0 g of polyethylene glycol 600 and 26.2 g of toluene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted at 60 °C with stirring for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 3.6 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 3.84 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, 20 g of acetone was added for dilution, and 1.8 g of acetic acid was added for neutralization. The reaction was stirred for 0.5 h. 381.8 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove the acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0046] (2) Preparation reaction of polyacrylate emulsion 1.0 g of hexadecyltrimethylammonium chloride and 1.0 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl methacrylate, 1.0 g of hydroxyethyl acrylate, 4.0 g of isobornyl acrylate, and 25.0 g of the polyurethane dispersion emulsion from reaction (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was completed, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0047] Example 4 (1) Preparation reaction of polyurethane dispersion emulsion Under a nitrogen atmosphere, 50.0 g of polyethylene glycol 800 and 26.2 g of hexamethylene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted at 60 °C with stirring for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 3.6 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 3.84 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, diluted, and neutralized with 0.9 g of acetic acid. The reaction was stirred for 0.5 h. 334.6 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0048] (2) Preparation reaction of polyacrylate emulsion 3.0 g of octadecyltrimethylammonium chloride and 1.0 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 160.0 g of deionized water. 40.0 g of octadecyl acrylate, 2.0 g of glycidyl methacrylate, and 50.0 g of the polyurethane dispersion emulsion from reaction (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 1.0 g of azobisisobutyramidine hydrochloride was dissolved in 60 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was complete, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0049] Example 5 The rest is the same as in Example 1, except that in step (1), the molecular weight of polyethylene glycol is 1000, which can also prepare a polyacrylate emulsion with good waterproof and easy-to-clean properties.

[0050] Figure 1 The image shows a transmission electron microscope (TEM) image of the polyacrylate emulsion latex particles prepared in Example 3. As can be seen from the image, the latex particles are approximately 120 nm in size, spherical in shape, and relatively uniformly distributed.

[0051] Figure 2 Contents (a) and (b) represent optical photographs of the original fabric after it has been stained and of the fabric sample treated with the polyacrylate emulsion prepared in Example 3, respectively. As can be seen from content (a), the stain is quite obvious, and the stain-removing level is measured to be 2.5. However, in content (b), the stain is not visible after treatment, and the stain-removing level is measured to be 5.

[0052] Comparative Example 1 (1) Preparation reaction of polyurethane dispersion Under a nitrogen atmosphere, 40.0 g of polyethylene glycol 400 and 26.2 g of toluene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted with stirring at 60 °C for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 3.6 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 3.84 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, 20 g of acetone was added for dilution, and 1.8 g of acetic acid was added for neutralization. The reaction was stirred for 0.5 h. 294.6 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove the acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0053] (2) Preparation reaction of polyacrylate emulsion 1.0 g of hexadecyltrimethylammonium chloride and 1.0 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl methacrylate, 1.0 g of hydroxyethyl acrylate, 4.0 g of isobornyl acrylate, and 25.0 g of the polyurethane dispersion emulsion from reaction (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was completed, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0054] The difference between Comparative Example 1 and Example 3 is that in step (1), the molecular weight of polyethylene glycol is 400.

[0055] Comparative Example 2 (1) Preparation reaction of polyurethane dispersion Under a nitrogen atmosphere, 200.0 g of polyethylene glycol 2000 and 26.2 g of toluene diisocyanate, which had been dehydrated under vacuum, were mixed in a four-necked flask and reacted with stirring at 60 °C for 2 h. 1-2 drops of stannous octoate were added, and the reaction was continued at this temperature for another 2 h. 3.6 g of N-methyldiethanolamine was added, and the reaction was continued at this temperature for another 1 h. 3.84 g of 3,5-dimethylpyrazole was added, and the reaction was continued at this temperature for another 1 h. The temperature was lowered to 45 °C, 20 g of acetone was added for dilution, and 1.8 g of acetic acid was added for neutralization. The reaction was stirred for 0.5 h. 766.8 g of deionized water was added for emulsification, and the mixture was stirred for 0.5 h to remove the acetone solvent, yielding a polyurethane dispersion emulsion with a solid content of 20%.

[0056] (2) Preparation reaction of polyacrylate emulsion 1.0 g of hexadecyltrimethylammonium chloride and 1.0 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl methacrylate, 1.0 g of hydroxyethyl acrylate, 4.0 g of isobornyl acrylate, and 25.0 g of the polyurethane dispersion emulsion from reaction (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was completed, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion.

[0057] The difference between Comparative Example 2 and Example 3 is that in step (1), the molecular weight of polyethylene glycol is 2000.

[0058] Comparative Example 3 (1) Same as Example 1; (2) Preparation reaction of polyacrylate emulsion 1.5 g of octadecyltrimethylammonium chloride and 0.5 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl acrylate, 5.0 g of isobornyl methacrylate, and 25.0 g of the polyurethane dispersion emulsion from step (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was complete, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion. Comparative Example 3 is the same as Example 1, except that step (2) does not introduce the crosslinking component acrylate monomer.

[0059] Comparative Example 4 (1) Same as Example 1; (2) Preparation reaction of polyacrylate emulsion 1.5 g of octadecyltrimethylammonium chloride and 0.5 g of isotridecyl alcohol polyoxyethylene ether were dissolved in 80.0 g of deionized water. 20.0 g of octadecyl acrylate, 5.0 g of glycidyl methacrylate, and 25.0 g of the polyurethane dispersion emulsion from step (1) were added to the above aqueous solution. The mixture was stirred at high speed at 60 °C for 15 min, followed by sonication for 40 min to obtain a pre-emulsion. 0.5 g of azobisisobutyramidine hydrochloride was dissolved in 30 g of deionized water and added dropwise to the above pre-emulsion at 65 °C over a period of 0.5 h. The mixture was then kept at this temperature for 4 h. After the reaction was complete, heating was stopped, the temperature was lowered to below 45 °C, and the mixture was filtered to obtain the polyacrylate emulsion. Comparative Example 4 is the same as Example 1, except that step (2) does not introduce the sterically hindered component acrylate monomer.

[0060] Figure 3 These are optical microscope images of the wetted and waterproof fabrics obtained by applying polyacrylic acid emulsion to the fabrics prepared in Comparative Examples 2 and 3 and then wetting them. Content A represents a small amount of water droplets remaining on the fabric surface, with a waterproof score of 80; Content B represents no water droplet residue, with a waterproof score of 100.

[0061] The performance of white cotton twill fabrics treated with the fabric finishing agent prepared from the polyacrylate emulsions of Examples 1-4 and Comparative Examples 1-4 was tested. At the same time, the performance of untreated white cotton twill fabrics was also tested as a blank control group. The results are shown in Table 1.

[0062] Waterproof performance testing standard: Waterproof performance testing shall be conducted in accordance with AATCC 22-2017 "Water repellency: Spray test".

[0063] Easy-to-clean performance test standard: The easy-to-clean performance test shall be conducted in accordance with the AATCC 130-2018 "Easy-to-clean performance test standard".

[0064] Washability test standard: Washability test method - dimensional stability of household washing (AATCC 135-2018) is used. The product is washed 5 times and dried after washing.

[0065] Note: The highest waterproof score in the table is 100 points; the lower the number, the worse the waterproof performance. The highest stain-resistant rating is 5; the lower the number, the worse the stain-resistant performance.

[0066] Table 1

[0067] As shown in Table 1, the untreated fabric sample (blank control) scored 0 points for water resistance, and its stain resistance ratings after initial washing and after 5 washes were 3.0 and 2.5, respectively. In contrast, the fabric samples treated with the polyacrylate emulsions prepared in Examples 1 to 4 exhibited superior water resistance and stain resistance. In particular, the sample from Example 2, after treatment, achieved water resistance scores of 100 and 95 points after initial washing and after 5 washes, respectively, and stain resistance ratings of 5.0 and 4.5, respectively.

[0068] The molecular weight of polyethylene glycol in Comparative Example 1 was only 400, while that in Comparative Example 2 was 2000. It can be seen that when the molecular weight of the polyacrylate emulsion is too low or too high, the fabric sample treated with it has good waterproof performance but poor stain removal performance; when the stain removal performance is good, the waterproof score is low; the two functions cannot be achieved at the same time.

[0069] Comparative Example 3 is otherwise the same as Example 1, except that step (2) does not introduce the crosslinking component acrylate monomer; Comparative Example 4 is otherwise the same as Example 1, except that step (2) does not introduce the sterically hindered component acrylate monomer. It can be seen that the waterproofing scores of the fabric samples treated with polyacrylate emulsions obtained in Comparative Examples 3 and 4 are both low.

[0070] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a waterproof and easy-to-clean fluorine-free acrylate emulsion, characterized in that, Includes the following steps: (1) Under a protective atmosphere, the polyurethane prepolymer is diluted with a solvent and mixed with a neutralizing agent, stirred and reacted, then water is added for emulsification, and after removing the solvent, a polyurethane dispersion emulsion is obtained. (2) Dissolve the composite emulsifier in water, mix it with the acrylate monomer and the polyurethane dispersion emulsion described in step (1), heat and stir to emulsify it, and obtain a pre-emulsion; (3) Under heating conditions, the initiator is introduced into the pre-emulsion described in step (2), and the temperature is maintained to allow the acrylate monomers to undergo a polymerization reaction. After the reaction is completed, the temperature is lowered to obtain a waterproof and easy-to-clean fluorine-free acrylate emulsion. The polyurethane prepolymer in step (1) is obtained by urethane esterification reaction of polyol and isocyanate under the condition of sequential addition of catalyst, chain extender and end capping agent; The molecular weight of the polyol is 500~1500 g / mol; the polyol is one or more of polyethylene glycol and polypropylene glycol; The isocyanate is one or more selected from toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and diphenylmethane diisocyanate; The acrylate monomers in step (2) are a mixture of hydrophobic acrylate monomers, crosslinking acrylate monomers, and sterically hindered acrylate monomers, wherein, The hydrophobic component acrylate monomer is one or more of octadecyl acrylate, octadecyl methacrylate, heptadecanyl acrylate, and hexadecyl acrylate; The crosslinking component acrylate monomer is one or more of glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate; The sterically hindered component acrylate monomer is one or more of isoborneol acrylate and isoborneol methacrylate; The mass ratio of the hydrophobic component acrylate monomer, the crosslinking component acrylate monomer, and the sterically hindered component acrylate monomer is 20:1:(1~5).

2. The preparation method according to claim 1, characterized in that, The catalyst is one or more selected from stannous octanoate, dibutyltin dilaurate, and bismuth isooctanoate; the chain extender is one or more selected from N-methyldiethanolamine, N-ethyldiethanolamine, and N,N-dihydroxyethylpiperazine; the end-capping agent is one or more selected from 3,5-dimethylpyrazole, butanone oxime, and caprolactam; and / or... The mass ratio of the polyol to the isocyanate is (1~5):1; and / or, The neutralizing agent in step (1) is acetic acid and / or hydrochloric acid.

3. The preparation method according to claim 1, characterized in that, The composite emulsifier in step (2) is a mixture of cationic and nonionic emulsifiers, wherein the cationic emulsifier is one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and dodecyldimethylbenzylammonium chloride; the nonionic emulsifier is one or more of isomeric alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and isomeric secondary alcohol polyoxyethylene ether; the mass ratio of the cationic emulsifier to the nonionic emulsifier is 1:1 to 3:1, and the amount of the composite emulsifier is 5 to 10% of the total mass of the acrylate monomers.

4. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of the polyurethane dispersion emulsion to the acrylate monomer is (0.8~1.2):1, and the solid content of the polyurethane dispersion emulsion is 15-25%. The heating and stirring are performed at 50-60℃ for 10-20 minutes, followed by ultrasonication for 20-40 minutes.

5. The preparation method according to claim 1, characterized in that, The initiator in step (3) is one or more of azobisisobutyramidine hydrochloride, ammonium persulfate and potassium persulfate, and the amount of the initiator is 1 to 2% of the total mass of the acrylate monomers.

6. A waterproof and easy-to-clean non-fluorinated polyacrylate emulsion prepared by the preparation method according to any one of claims 1 to 5.

7. The use of the waterproof and stain-resistant non-fluorinated polyacrylate emulsion as described in claim 6 in its use or preparation as a fabric finishing agent.

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