Wear-resistant antistatic water-based polyurethane film-forming agent, preparation method and application

Abstract

This invention relates to the field of chopped glass fiber modification technology, and particularly to a wear-resistant and antistatic waterborne polyurethane film-forming agent, its preparation method, and its application. This invention uses low molecular weight polycarbonate diol and diisocyanate as main raw materials, constructing a waterborne polyurethane molecular structure with high hard segment content through prepolymerization and chain extension reactions. Aniline monomers are introduced into the polyurethane prepolymer, and under acidic conditions, a free radical-initiated reaction is used to chemically graft polyaniline segments onto the polyurethane molecules, resulting in a polyaniline-grafted modified waterborne polyurethane dispersion. This allows the final film-forming agent to form a film on the glass fiber surface with high structural stability and wear resistance. Simultaneously, polyaniline forms a continuous conductive pathway in the acidic doping state, exhibiting antistatic properties, thus solving the problems of poor wear resistance and antistatic performance in existing waterborne polyurethane film-forming agents.

Description

Technical Field

[0001] This invention relates to the field of chopped glass fiber modification technology, specifically to a wear-resistant and antistatic waterborne polyurethane film-forming agent, its preparation method, and its application. Background Technology

[0002] Chopped glass fiber (CFB) is a reinforcing material made primarily from raw materials such as quartz sand. It is produced by high-temperature melting and drawing into continuous filaments, with a sizing agent applied during the drawing process to form a surface treatment layer. The resulting bundled and cut fiber is widely used in the automotive, construction, aerospace, and electronics industries. With the development of new energy vehicles and the increasing demand for lightweight vehicles, higher requirements are being placed on the processing stability and overall performance of CFB and its reinforced composites. In the preparation and application of CFB, film-forming sizing agents, as a key functional layer on the fiber surface, can form a continuous polymer film on the glass fiber surface. Their main functions are to protect the fiber surface structure, improve the bundle state between fibers, and promote the dispersion and compatibility of CFB in the resin matrix during subsequent processing.

[0003] Waterborne polyurethane film-forming agents have become a commonly used organic film-forming component in chopped glass fiber impregnation systems due to their good flexibility and strong structural designability. However, in the actual production and processing of chopped glass fibers, multiple processes such as high-speed traction, mechanical cutting, and pipeline transportation are required, placing extremely high demands on the wear resistance and antistatic properties of the film-forming agent. Currently, the crosslinking structure of waterborne polyurethane is mainly formed through hydrogen bonds between hard segments or by adding a small amount of crosslinking agent. However, due to the dispersion requirements of the waterborne system, the amount of crosslinking agent added is usually <2%, resulting in insufficient film cohesion and easy crack propagation under frictional stress. Simultaneously, existing antistatic agents often rely on conductive fillers (such as carbon black and carbon nanotubes) or ionic antistatic agents (such as quaternary ammonium salts) in the film-forming agent to form a conductive network. Similarly, limited by the dispersion requirements of the waterborne system, the amount added is often too small, making it difficult to form a continuous pathway and resulting in weak antistatic performance. This leads to fuzzing, wear, and static electricity accumulation in the fibers during traction, cutting, and transportation, further causing phenomena such as chopped glass fiber agglomeration and uneven dispersion. These problems not only affect the processing of modified plastics, but also have an adverse impact on the appearance quality and mechanical properties of the products, thus restricting the application performance and production efficiency of chopped glass fibers and their composites.

[0004] In summary, the shortcomings of existing waterborne polyurethane film-forming agents in terms of anti-friction damage and antistatic properties have become a core bottleneck restricting the high-end development of chopped glass fibers. Developing a waterborne polyurethane film-forming agent that combines high wear resistance, durable antistatic properties, and excellent bundle bonding has become crucial to meeting the needs of new energy vehicle development and automotive lightweighting. Summary of the Invention

[0005] To address the problems of poor wear resistance and antistatic properties of existing waterborne polyurethane film-forming agents, this invention provides a wear-resistant and antistatic waterborne polyurethane film-forming agent, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a wear-resistant and antistatic waterborne polyurethane film-forming agent, comprising the following raw material components by weight: 30-40 parts of polycarbonate diol, 10-40 parts of isocyanate, 5-7 parts of hydrophilic chain extender, 0.5-1 part of small molecule chain extender, 15-22 parts of aniline, and 36-50 parts of free radical initiator; wherein the molecular weight of the polycarbonate diol is 500-2000.

[0007] Optionally, the isocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or hexamethylene diisocyanate.

[0008] Optionally, the hydrophilic chain extender is one or more of sodium 2-(diethanolamine)ethanesulfonate, 2,2-dimethylolbutyric acid, 2,2-dimethylolpropionic acid, and sodium 1,2-propanediol-3-sulfonate.

[0009] Optionally, the small molecule chain extender is one or more of ethylene glycol, propylene glycol, and 1,4-butanediol.

[0010] Optionally, the free radical initiator is potassium persulfate and / or ammonium persulfate.

[0011] This invention also provides a method for preparing the above-described wear-resistant and antistatic waterborne polyurethane film-forming agent, comprising: Polycarbonate diol is subjected to high-temperature dehydration treatment; Polycarbonate diol, after high-temperature dehydration, isocyanate is subjected to a prepolymerization reaction under catalyst conditions to obtain a prepolymer. A hydrophilic chain extender and a small molecule chain extender are added to the prepolymer to carry out a chain extension reaction, thereby obtaining a PU prepolymer; Aniline was added to the PU prepolymer to carry out a polymerization reaction, resulting in An-PU prepolymer; Water is added to the An-PU prepolymer for emulsification to form an An / WPU dispersion; After adjusting the pH of the An / WPU dispersion, a free radical initiator was added, and the reaction yielded a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0012] Optionally, the high-temperature dehydration treatment is carried out at a temperature of 100-120°C for a time of 50-70 minutes.

[0013] Optionally, during the emulsification process of adding water to the An-PU prepolymer, the amount of water added is 140-200 parts.

[0014] Optionally, the catalyst is dibutyltin dilaurate, and the mass ratio of the catalyst to polycarbonate diol is (0.01-0.03):(30-40); the pH value of the An / WPU dispersion is adjusted to 0-4 using hydrochloric acid solution.

[0015] Application of the above-mentioned wear-resistant and antistatic waterborne polyurethane film-forming agent in the preparation of chopped glass fibers and their composites.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a wear-resistant and antistatic waterborne polyurethane film-forming agent. By optimizing the raw material formulation and molecular structure design, the designed waterborne polyurethane film-forming agent possesses high wear resistance, long-lasting antistatic properties, and excellent storage stability. This invention selects low molecular weight polycarbonate diols with a molecular weight of 500-2000 as the soft segment. These soft segments have a higher number of hydroxyl groups per unit mass, and when reacting with diisocyanate, they can form a higher proportion of hard segments, significantly increasing the hydrogen bond density and cohesive energy between molecular chains. The high hard segment content forms a physical cross-linking network through hydrogen bonding, restricting the free movement of molecular chains and making the film layer less prone to plastic deformation or breakage during friction, thus significantly improving wear resistance. Furthermore, chemical graft polymerization is used to form chemical bonds between the polyaniline chains and the waterborne polyurethane backbone, enhancing the interaction between the polyaniline and waterborne polyurethane chains and preventing polyaniline from detaching during friction. The rigid structure of polyaniline further strengthens the film layer hardness, further improving the wear resistance of the film-forming agent. Meanwhile, by leveraging the synergistic effect of anionic and nonionic segments in waterborne polyurethane, segment polarity can be reduced, achieving an antistatic effect. Furthermore, polyaniline, under acidic conditions, undergoes oxidative polymerization via a free radical initiator to form an ES-doped state with a large π-conjugated structure. + As a dopant, it generates polaron conductive sites, enabling polyaniline to construct a continuous conductive path, significantly reducing surface resistivity. Ultimately, the electrostatic charge generated on the material surface can be quickly conducted and dissipated through the highly conductive network of polyaniline, thereby achieving efficient antistatic function and solving the problem of poor antistatic effect of existing waterborne polyurethane film-forming agents.

[0017] This invention also provides a method for preparing the aforementioned wear-resistant and antistatic waterborne polyurethane film-forming agent. This method involves high-temperature dehydration of polycarbonate diol to prevent residual moisture from combining with isocyanate, which could lead to prepolymer gelation or increased porosity, affecting the film's density and mechanical properties. Then, the dehydrated polycarbonate diol is prepolymerized with isocyanate to form a prepolymer with a high hard segment ratio. Next, hydrophilic chain extenders and small molecule chain extenders are added to introduce carboxylic acid groups and urethane bonds to form a two-phase micro-separated structure, balancing hardness and flexibility. Finally, in-situ polymerization with aniline allows aniline to oxidatively polymerize on the polyurethane chain to form polyaniline. Simultaneously, urea bonds are generated through the reaction of amino groups and isocyanate groups, achieving chemical grafting of polyaniline. Under the action of a free radical initiator, polymerization forms an ES-doped state with a large π-conjugated structure, enabling polyaniline to construct a continuous conductive path, significantly reducing surface resistivity and improving the antistatic properties of the film-forming agent. Emulsification balances processability and film performance. This method, through simple high-temperature dehydration, stepwise reaction control, in-situ chemical grafting, and post-treatment optimization, systematically solves the problems of insufficient wear resistance, poor antistatic effect, low dispersion stability, and contradictory processing performance in existing technologies. It provides a high-performance film-forming agent preparation solution for the high-end application of chopped glass fibers in new energy vehicles, aerospace, and electronics.

[0018] The aforementioned wear-resistant and antistatic waterborne polyurethane film-forming agent is applied in the preparation of chopped glass fibers and their composites. This film-forming agent can form a tough protective film on the surface of the glass fibers, significantly enhancing the fiber's bundle properties and preventing it from easily scattering during the chopping process, thus maintaining a neat arrangement. Simultaneously, due to the excellent wear resistance and antistatic properties of this film-forming agent, it can significantly improve the bundle properties, choppedness, and wear resistance of the glass fibers. Therefore, when this fiber is used as a reinforcing material in composite materials, it can effectively improve the mechanical properties of the composite materials, such as strength, stiffness, and durability, meeting the high-end application requirements of chopped glass fibers in new energy vehicles, aerospace, and electronics. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation method of a wear-resistant and antistatic waterborne polyurethane film-forming agent according to the present invention. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0027] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0028] This invention discloses a wear-resistant and antistatic waterborne polyurethane film-forming agent, comprising the following raw material components by mass: 30-40 parts of polycarbonate diol, 10-40 parts of isocyanate, 5-7 parts of hydrophilic chain extender, 0.5-1 parts of small molecule chain extender, 15-22 parts of aniline, and 36-50 parts of free radical initiator; wherein the polycarbonate diol has a molecular weight of 500-2000, and the polycarbonate diol is ε-caprolactone-initiated polycarbonate diol and / or polytetramethylene ether diol-initiated polycarbonate diol.

[0029] Preferably, the isocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or hexamethylene diisocyanate; the hydrophilic chain extender is one or more of sodium 2-(diethanolamine)ethanesulfonate, 2,2-dimethylolbutyric acid, 2,2-dimethylolpropionic acid, and sodium 1,2-propanediol-3-sulfonate; the small molecule chain extender is one or more of ethylene glycol, propylene glycol, and 1,4-butanediol; and the free radical initiator is potassium persulfate and / or ammonium persulfate.

[0030] See Figure 1 This invention provides a method for preparing the wear-resistant and antistatic waterborne polyurethane film-forming agent as described above, comprising: S1: Polycarbonate diol undergoes high-temperature dehydration treatment, specifically: Under vacuum conditions, polycarbonate diol is placed at 100-120°C for 50-70 minutes for high-temperature dehydration treatment to complete the high-temperature dehydration treatment.

[0031] S2: Polycarbonate diol, after high-temperature dehydration, isocyanate is reacted with a catalyst under catalytic conditions to obtain a prepolymer, specifically: Under a nitrogen protective atmosphere, polycarbonate diol after warm dehydration treatment is mixed with isocyanate, and a catalyst is added. The mixture is then subjected to a prepolymerization reaction at 75-90℃ for 1-3 hours to obtain a prepolymer. The catalyst is dibutyltin dilaurate, and the mass ratio of the catalyst to polycarbonate diol is (0.01-0.03):(30-40). S3: Add a hydrophilic chain extender and a small molecule chain extender to the prepolymer to carry out a chain extension reaction, thereby obtaining the PU prepolymer, specifically as follows: A hydrophilic chain extender and a small molecule chain extender are added to the prepolymer, and the chain extension reaction is carried out at 75-90℃ for 30-60 min to obtain the PU prepolymer. S4: Add aniline to the PU prepolymer to carry out a polymerization reaction, and obtain An-PU prepolymer, specifically: Aniline was added to the PU prepolymer, and the reaction was carried out at room temperature for 2-3 hours to obtain An-PU prepolymer; S5: Emulsify with water into the An-PU prepolymer to form an An / WPU dispersion, specifically: At room temperature, with a stirring speed of 1200-1500 rpm, 140-200 parts of deionized water are added to the An-PU prepolymer for emulsification, and the An / WPU dispersion is obtained. The An / WPU dispersion is in the form of a white emulsion.

[0032] S6: After adjusting the pH of the An / WPU dispersion, a free radical initiator is added, and the reaction yields a wear-resistant and antistatic waterborne polyurethane film-forming agent, specifically: After adjusting the pH value to 0-4 by adding hydrochloric acid solution to the waterborne polyurethane dispersion, a free radical initiator is added dropwise, and the reaction is carried out at 0-60℃ for 18-30 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0033] This film-forming agent uses polycarbonate diol and diisocyanate as main raw materials. A high-hardness-segment content waterborne polyurethane molecular structure is constructed through prepolymerization and chain extension reactions. Aniline monomers are introduced into the polyurethane prepolymer, and under acidic conditions, a free radical-initiated reaction chemically grafts polyaniline segments onto the polyurethane molecules, yielding a polyaniline-grafted waterborne polyurethane dispersion. The film formed on the glass fiber surface by this film-forming agent exhibits high structural stability and wear resistance. Simultaneously, the polyaniline forms a continuous conductive path in the acidic doping state, giving the film antistatic properties. This makes it suitable for surface treatment of chopped glass fibers, improving their bundle stability, wear resistance, and antistatic properties during processing.

[0034] The application of the aforementioned wear-resistant and antistatic waterborne polyurethane film-forming agent in the preparation of chopped glass fibers and their composites can significantly improve the bundle properties, choppedness, and wear resistance of glass fibers. This allows the fiber to effectively improve the strength, stiffness, and durability of composite materials when used as a reinforcing material, thus meeting the high-end application requirements of chopped glass fibers in new energy vehicles, aerospace, and electronics.

[0035] Example 1 Weigh 40g of polycarbonate diol initiated by ε-caprolactone with a molecular weight of 500 and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 1 hour.

[0036] Subsequently, under a nitrogen atmosphere and at 80°C, 38 g of 4,4'-dicyclohexylmethane diisocyanate and 0.02 g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 80°C for 1.5 h, a prepolymer was obtained. Then, 6.8 g of sodium 2-(diethanolamine)ethanesulfonate and 0.9 g of 1,4-butanediol were added to the prepolymer sequentially, and the reaction was continued at 80°C for 1 h to obtain the PU prepolymer.

[0037] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 21.4 g of aniline was added, and the reaction was continued for 2.5 h to obtain An-PU prepolymer.

[0038] The reaction system (An-PU prepolymer) was cooled to room temperature, and 170g of deionized water was slowly added under a stirring speed of 1300rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 50 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40℃, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0039] Example 2 Weigh 40g of polycarbonate diol initiated by ε-caprolactone with a molecular weight of 1000 and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 1 hour.

[0040] Subsequently, under a nitrogen atmosphere and at 80°C, 24 g of 4,4'-dicyclohexylmethane diisocyanate and 0.02 g of dibutyltin dilaurate were added. After reacting at a constant temperature of 80°C for 1.5 h, the prepolymer was obtained. Continue to add 5.6 g of sodium 2-(diethanolamine)ethanesulfonate and 1 g of 1,4-butanediol to the prepolymer in sequence, and continue to react at 80 °C for 1 h to obtain PU prepolymer.

[0041] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 17.6 g of aniline was added, and the reaction was continued for 2.5 h to obtain An-PU prepolymer.

[0042] The reaction system (An-PU prepolymer) was cooled to room temperature, and 160g of deionized water was slowly added under a stirring speed of 1300rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 42 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40°C, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0043] Example 3 Weigh 40g of polycarbonate diol initiated by ε-caprolactone with a molecular weight of 2000 and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 1 hour.

[0044] Subsequently, under a nitrogen atmosphere and at 80°C, 15 g of 4,4'-dicyclohexylmethane diisocyanate and 0.02 g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 80°C for 1.5 h, the prepolymer was obtained. Continue to add 5 g of sodium 2-(diethanolamine)ethanesulfonate and 0.5 g of 1,4-butanediol to the prepolymer in sequence, and continue to react at 80℃ for 1 h to obtain PU prepolymer.

[0045] After the reaction was complete, the system was cooled to 30°C, 15 g of aniline was added, and the reaction was continued for 2.5 h to obtain An-PU prepolymer.

[0046] The reaction system was cooled to room temperature, and 160g of deionized water was slowly added under vigorous stirring to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1mol / L hydrochloric acid solution. 36g of ammonium persulfate was dissolved in water, and a 0.2mol / L ammonium persulfate solution was added dropwise to the An / WPU dispersion. The reaction temperature was controlled (0-60℃), and the reaction was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0047] Example 4 Weigh 40 g of polytetramethylene ether glycol (molecular weight 500) and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 1 h.

[0048] Subsequently, under a nitrogen atmosphere and at 80 °C, 38 g of 4,4'-dicyclohexylmethane diisocyanate and 0.02 g of dibutyltin dilaurate were added to the four-necked flask. After reacting at a constant temperature of 80 °C for 1.5 h, 6.8 g of sodium 2-(diethanolamine)ethanesulfonate and 0.9 g of 1,4-butanediol were added to the prepolymer sequentially, and the reaction was continued at 80 °C for 1 h.

[0049] After the reaction was complete, the system was cooled to 30°C, 21.4 g of aniline was added, and the reaction was continued for 2.5 h to obtain An-PU prepolymer.

[0050] The reaction system was cooled to room temperature, and 140g of deionized water was slowly added under vigorous stirring to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1mol / L hydrochloric acid solution. 50g of ammonium persulfate was dissolved in water to form a 0.2mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40℃, and the reaction was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0051] Example 5 Weigh 40g of polytetramethylene ether glycol (molecular weight 1000) and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 1 hour.

[0052] Subsequently, under a nitrogen atmosphere and at 80°C, 24 g of 4,4'-dicyclohexylmethane diisocyanate and 0.02 g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 80°C for 1.5 h, the prepolymer was obtained. Continue to add 5.6 g of sodium 2-(diethanolamine)ethanesulfonate and 1 g of 1,4-butanediol to the prepolymer in sequence, and continue to react at 80 °C for 1 h.

[0053] After the reaction was complete, the system was cooled to 30°C, and 17.6 g of aniline was added. The reaction was continued for 2.5 h to obtain the An-PU prepolymer. The reaction system was cooled to room temperature, and 140 g of deionized water was slowly added under vigorous stirring to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 with a 1 mol / L hydrochloric acid solution.

[0054] 42 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the dispersion. The reaction temperature was controlled at 50 °C, and the reaction was continuously stirred for 24 h to obtain the PANI-g-WPU dispersion.

[0055] Example 6 40 g of polytetramethylene ether glycol (molecular weight 2000) was weighed and added to a four-necked flask, and dehydrated under vacuum at 100 °C for 1 h. Then, under a nitrogen atmosphere at 80 °C, 10 g of hexamethylene diisocyanate and 0.02 g of dibutyltin dilaurate were added. After reacting at 80 °C for 1.5 h, 5 g of sodium 2-(diethanolamine)ethanesulfonate and 0.5 g of 1,4-butanediol were added sequentially, and the reaction was continued at 80 °C for another 1 h. After the reaction was complete, the system was cooled to 40 °C, and 2 g of triethylamine was added for neutralization for 20 min. Then, 15 g of aniline was added, and the reaction was continued for 2.5 h to obtain the An-PU prepolymer. The reaction system was cooled to room temperature, and 150g of deionized water was slowly added under vigorous stirring to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 with a 1mol / L hydrochloric acid solution. 36g of ammonium persulfate was dissolved in water to form a 0.2mol / L ammonium persulfate solution, which was then added dropwise to the dispersion. The reaction temperature was controlled (0-60℃), and the reaction was continuously stirred for 24 h to obtain the PANI-g-WPU dispersion, which is a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0056] Example 7 Weigh 30g of polycarbonate diol initiated by ε-caprolactone with a molecular weight of 1000 and add it to a four-necked flask. Dehydrate under vacuum at 120°C for 50min.

[0057] Subsequently, under a nitrogen atmosphere and at 75°C, 10g of hexamethylene diisocyanate and 0.02g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 75°C for 3 hours, a prepolymer was obtained. Then, 3g of 2,2-dimethylolpropionic acid, 2g of sodium 1,2-propanediol-3-sulfonate, and 0.5g of propylene glycol were added to the prepolymer in sequence, and the reaction was continued at 75°C for 1 hour to obtain the PU prepolymer.

[0058] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 15g of aniline was added, and the reaction was continued for 2.5h to obtain An-PU prepolymer.

[0059] The reaction system (An-PU prepolymer) was cooled to room temperature, and 140g of deionized water was slowly added under a stirring speed of 1300rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 36 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40℃, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0060] Example 8 Weigh 35g of polycarbonate diol with a molecular weight of 1500 and add it to a four-necked flask. Dehydrate under vacuum at 110°C for 60 minutes.

[0061] Subsequently, under a nitrogen atmosphere and at 90°C, 10g of hexamethylene diisocyanate, 20g of 4,4'-dicyclohexylmethane diisocyanate, and 0.03g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 90°C for 1 hour, a prepolymer was obtained. Then, 3g of 2,2-dimethylolpropionic acid, 3g of sodium 2-(diethanolamine)ethanesulfonate, 0.5g of propylene glycol, and 0.5g of ethylene glycol were added to the prepolymer in sequence, and the reaction was continued at 90°C for 1 hour to obtain the PU prepolymer.

[0062] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 18g of aniline was added, and the reaction was continued for 2.5h to obtain An-PU prepolymer.

[0063] The reaction system (An-PU prepolymer) was cooled to room temperature, and 200g of deionized water was slowly added under a stirring speed of 1300rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 45 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40°C, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0064] Example 9 Weigh 333g of polycarbonate diol with a molecular weight of 1000 and add it to a four-necked flask. Dehydrate under vacuum at 100°C for 60 minutes.

[0065] Subsequently, under a nitrogen atmosphere and at 80°C, 15g of hexamethylene diisocyanate, 5g of 4,4'-dicyclohexylmethane diisocyanate, and 0.02g of dibutyltin dilaurate were added to the above four-necked flask. After reacting at a constant temperature of 80°C for 1 hour, a prepolymer was obtained. Then, 7g of 2,2-dimethylolpropionic acid, 0.3g of propylene glycol, and 0.4g of ethylene glycol were added to the prepolymer in sequence, and the reaction was continued at 80°C for 1 hour to obtain the PU prepolymer.

[0066] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 22g of aniline was added, and the reaction was continued for 2.5h to obtain An-PU prepolymer.

[0067] The reaction system (An-PU prepolymer) was cooled to room temperature, and 190g of deionized water was slowly added under a stirring speed of 1500rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 37 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40°C, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0068] Example 10 Weigh 36g of polycarbonate diol with a molecular weight of 2000 and add it to a four-necked flask. Dehydrate under vacuum at 110℃ for 60min.

[0069] Subsequently, under a nitrogen atmosphere and at 80°C, 25g of hexamethylene diisocyanate and 0.02g of dibutyltin dilaurate were added to the four-necked flask. After reacting at a constant temperature of 80°C for 1 hour, a prepolymer was obtained. Then, 5.5g of 2,2-dimethylolpropionic acid, 0.3g of propylene glycol, 0.3g of ethylene glycol, and 0.1g of 1,4-butanediol were added to the prepolymer in sequence, and the reaction was continued at 80°C for 1 hour to obtain a PU prepolymer.

[0070] After the reaction was completed, the system (PU prepolymer) was cooled to 30°C, 21g of aniline was added, and the reaction was continued for 2.5h to obtain An-PU prepolymer.

[0071] The reaction system (An-PU prepolymer) was cooled to room temperature, and 150g of deionized water was slowly added under a stirring speed of 1400rpm to emulsify and form a uniform An / WPU dispersion. The pH of the An / WPU dispersion was adjusted to 0-4 using a 1 mol / L hydrochloric acid solution. 47 g of ammonium persulfate was dissolved in water to form a 0.2 mol / L ammonium persulfate solution, which was then added dropwise to the An / WPU dispersion. The reaction temperature was controlled at 40°C, and the mixture was continuously stirred for 24 hours to obtain a wear-resistant and antistatic waterborne polyurethane film-forming agent.

[0072] Comparative Example 1 Unlike Example 1, aniline was not added, but the remaining steps were the same.

[0073] Comparative Example 2 Unlike Example 1, polycarbonate diol was replaced with polyethylene glycol.

[0074] Comparative Example 3 Unlike Example 1, polycarbonate diol was replaced with polyethylene glycol, and aniline was not added; the remaining steps were the same.

[0075] The aqueous polyurethane film-forming agents prepared in Examples 1-6 and Comparative Examples 1-3 were poured into polytetrafluoroethylene molds, dried in an 80°C oven, and subjected to a series of performance tests. Abrasion resistance was determined according to GB / T 30314-2021, and antistatic properties were determined according to ASTM D257. Abrasion resistance test data are shown in the table below: Mass loss (mg) Example 1 0.5 Example 2 1.9 Example 3 2.7 Example 4 6.5 Example 5 7.2 Example 6 8.5 Comparative Example 1 43 Comparative Example 2 5.2 Comparative Example 3 50 As can be seen from the table above, the abrasion resistance of the waterborne polyurethane film-forming agent prepared by this invention is significantly enhanced. Compared with Comparative Examples 1 and 3, where the soft segments are polyether-type polyols, the mass loss of Examples 1-6 and Comparative Example 2, where the soft segments are polycarbonate-type polyols, is significantly less. Furthermore, as the molecular weight of the polyol decreases, a higher proportion of hard segments can be formed when reacting with diisocyanate, significantly increasing the hydrogen bond density and cohesive energy between molecular chains. This forms a physical cross-linking network through hydrogen bonds, restricting the free movement of molecular chains and thus enhancing the abrasion resistance of the waterborne polyurethane film-forming agent.

[0076] The antistatic performance test results are shown in the table below: Surface resistivity (Ω·cm) Example 1 1.5 Example 2 4.1 Example 3 3.8 Example 4 2.7 Example 5 3.3 Example 6 5.2 Comparative Example 1 4.6 Comparative Example 2 118 Comparative Example 3 127 As can be seen from the table above, the waterborne polyurethane film-forming agent synthesized in this invention exhibits significantly improved antistatic properties. Compared to Comparative Examples 2 and 3 without polyaniline chemical grafting, the surface resistivity of Examples 1-6 and Comparative Example 1 with polyaniline chemical grafting is significantly reduced. This is mainly because polyaniline constructs a continuous conductive path, greatly reducing the surface resistivity. Ultimately, the electrostatic charge generated on the material surface can be rapidly conducted and dissipated through the highly conductive network of polyaniline, thereby achieving high antistatic properties.

[0077] To further verify the beneficial effects of the present invention, the aqueous polyurethane emulsions prepared in Examples 1-6 and Comparative Examples 1-3 were used as film-forming agents and applied to a mature chopped strand impregnating agent formulation to process glass fiber composite materials. The mechanical properties, bundle properties, abrasion resistance, and antistatic properties of these composite materials were then tested. Mechanical properties were determined according to GB / T 7689.5-2013. The filament content was calculated based on the ratio of the total mass of the chopped glass fiber sample to the mass of the sorted filaments. The fiber breakage rate was calculated based on the ratio of the number of broken fibers in the chopped glass fiber sample to the total number of samples.

[0078] The test results of the waterborne polyurethane film-forming agent after its application in chopped glass fiber processing are shown in the table below: Tensile strength (MPa) Broken fiber rate (%) Fiber content (g / 45kg) Static electricity Example 1 228 0.83 12.2 none Example 2 223 0.92 13.4 none Example 3 217 0.89 15.6 none Example 4 225 0.94 13.5 none Example 5 208 0.96 14.9 none Example 6 212 0.90 16.6 none Comparative Example 1 201 0.99 13.4 Strong Comparative Example 2 174 4.56 25.5 none Comparative Example 3 166 5.68 28.3 Strong As can be seen from the table above, the chopped glass fibers processed with the waterborne polyurethane film-forming agent synthesized in this invention exhibit good mechanical properties, with a significant decrease in both the broken fiber rate and fuzz content. Examples 1-6 and Comparative Example 2, modified with polyaniline, show no electrostatic phenomena. This indicates that the waterborne polyurethane film-forming agent synthesized in this invention, when used in the processing of chopped glass fibers, effectively improves the wear resistance and antistatic properties of the chopped glass fibers while ensuring good mechanical properties and film-forming properties.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A wear-resistant and antistatic waterborne polyurethane film-forming agent, characterized in that, The product comprises, by weight parts, the following raw material components: 30-40 parts of polycarbonate diol, 15-40 parts of isocyanate, 5-7 parts of hydrophilic chain extender, 0.5-1 part of small molecule chain extender, 15-22 parts of aniline, and 36-50 parts of free radical initiator; wherein the molecular weight of the polycarbonate diol is 500-2000.

2. The wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 1, characterized in that, The isocyanate is 4,4'-dicyclohexylmethane diisocyanate and / or hexamethylene diisocyanate.

3. The wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 1, characterized in that, The hydrophilic chain extender is one or more of sodium 2-(diethanolamine)ethanesulfonate, 2,2-dihydroxymethylbutyric acid, 2,2-dihydroxymethylpropionic acid, and sodium 1,2-propanediol-3-sulfonate.

4. The wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 1, characterized in that, The small molecule chain extender is one or more of ethylene glycol, propylene glycol, and 1,4-butanediol.

5. The wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 1, characterized in that, The free radical initiator is potassium persulfate and / or ammonium persulfate.

6. A method for preparing a wear-resistant and antistatic waterborne polyurethane film-forming agent as described in any one of claims 1-5, characterized in that, include: Polycarbonate diol is subjected to high-temperature dehydration treatment; Polycarbonate diol, after high-temperature dehydration, isocyanate is subjected to a prepolymerization reaction under catalyst conditions to obtain a prepolymer. A hydrophilic chain extender and a small molecule chain extender are added to the prepolymer to carry out a chain extension reaction, thereby obtaining a PU prepolymer; Aniline was added to the PU prepolymer to carry out a polymerization reaction, resulting in An-PU prepolymer; Water is added to the An-PU prepolymer for emulsification to form an An / WPU dispersion; After adjusting the pH of the An / WPU dispersion, a free radical initiator was added, and the reaction yielded a wear-resistant and antistatic waterborne polyurethane film-forming agent.

7. The method for preparing the wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 6, characterized in that, The high-temperature dehydration treatment is carried out at a temperature of 100-120℃ for 50-70 minutes.

8. The method for preparing the wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 6, characterized in that, During the emulsification process of the An-PU prepolymer with water, the amount of water added is 140-200 parts.

9. The preparation method of the wear-resistant and antistatic waterborne polyurethane film-forming agent according to claim 6, characterized in that, The catalyst is dibutyltin dilaurate, and the mass ratio of the catalyst to polycarbonate diol is (0.01-0.03):(30-40); the pH value of the An / WPU dispersion is adjusted to 0-4 using hydrochloric acid solution.

10. The application of the wear-resistant and antistatic waterborne polyurethane film-forming agent according to any one of claims 1-7 in the preparation of chopped glass fibers and their composites.

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