A high-dispersibility FDY oil agent special for dope dyeing fibers and a preparation method thereof

Abstract

The application relates to the technical field of textile auxiliaries, and provides a high-dispersibility FDY oil agent special for stock dyeing fibers and a preparation method thereof.The preparation method comprises the following steps: S100, adding an aqueous phase into an oil phase to obtain an emulsion after stirring; S200, sequentially adding an antistatic agent and a bundling agent into the emulsion, and sequentially performing first stirring treatment, standing treatment and filtration treatment to obtain the high-dispersibility FDY oil agent special for stock dyeing fibers; wherein the oil phase comprises a continuous lubricating film-forming unit and a boundary low-friction sliding unit.The application constructs a main oil film by using the continuous lubricating film-forming unit, strengthens boundary friction reduction by using the boundary low-friction sliding unit, obtains a high-dispersibility basic emulsion through phase inversion temperature emulsification, then introduces boundary sliding, antistatic and bundling functions in a later-added mode, and combines standing and gradient filtration to stabilize the system, so that the FDY oil agent suitable for stock dyeing fibers is prepared and has high dispersibility, low friction, wear resistance and processing stability.

Description

Technical Field

[0001] This application relates to the field of textile auxiliaries technology, and in particular to a highly dispersible FDY oil agent for solution-dyed fibers and its preparation method. Background Technology

[0002] FDY (Fully Drawn Yarn) is one of the important varieties of chemical fiber filaments, characterized by high orientation, high strength, and good dimensional stability. It is widely used in weaving, knitting, and industrial yarn industries. During FDY spinning, drawing, winding, and subsequent processing, spinning oil is typically applied to the fiber surface to impart suitable smoothness, antistatic properties, bundling, and post-processing stability, thereby reducing problems such as fuzz, breakage, flyaways, roller entanglement, and poor package formation.

[0003] With the widespread application of solution-dyed fibers, especially the rapid development of solution-dyed polyester and nylon filament products, the market has placed higher demands on specialized FDY oils suitable for solution-dyed fibers. Compared to unbleached fibers, solution-dyed fibers are colored fibers obtained by adding masterbatch, pigments, or functional fillers to the polymer melt before spinning, allowing the coloring components to be directly dispersed within the polymer and formed during spinning. Although these fibers have advantages such as energy saving and emission reduction, high color fastness, and shorter processing time, the introduction of pigments, masterbatch carriers, dispersants, and other additives often results in significant differences in fiber surface condition, surface energy, micro-roughness, and frictional behavior between fibers and between fibers and metals compared to conventional unbleached FDY.

[0004] In the existing technology, most FDY oil preparation methods adopt conventional compounding methods, which involve mixing and stirring the smoothing agent, emulsifier, antistatic agent, clustering agent and other additives at a certain temperature, and then cooling, settling and filtering to obtain the finished oil. While these methods are simple and easy to implement, their core remains the conventional physical mixing and emulsification process. They typically focus on the basic compatibility and short-term storage stability of the oil. However, for solution-dyed fibers, existing technologies still have the following shortcomings: First, conventional emulsion methods result in a wide particle size distribution, making it difficult to achieve emulsion structures with high interfacial stability and good film uniformity. This leads to insufficient spreading of the oil on the fiber surface and difficulty in forming a continuous oil film. Second, the surface roughness of solution-dyed fibers is high, and ordinary smoothing systems often only provide general lubrication, failing to balance continuous film formation and low-friction slip at the boundaries. This easily leads to local friction peaks between the fiber and metal contact parts, further exacerbating wear and process fluctuations. Third, the addition of antistatic and bundle components in the early stages can easily interfere with the droplet formation process, affecting the uniformity of the emulsion structure and consequently impacting oiling uniformity and fiber bundle stability. Fourth, some components in conventional oil systems are prone to local enrichment, coarse particle residue, or later precipitation, affecting the stability of the finished oil and potentially increasing contamination, deposition, or filtration burden in subsequent processing.

[0005] Therefore, there is an urgent need to develop a highly dispersible FDY oil agent specifically for solution-dyed fibers to meet production requirements. Summary of the Invention

[0006] In view of the above-mentioned shortcomings in the prior art, the purpose of this application is to provide a highly dispersible FDY oil agent for solution-dyed fibers and its preparation method.

[0007] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows: In a first aspect, embodiments of this application provide a method for preparing a highly dispersible FDY oil agent specifically for solution-dyed fibers, comprising: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200. Antistatic agent and bridging agent are added to the emulsion in sequence, and the first stirring treatment, standing treatment and filtration treatment are carried out in sequence to obtain a high dispersibility FDY oil agent for solution-dyed fibers. The oil phase includes a continuous lubrication film-forming unit and a boundary low-friction slip unit; S100 includes: S110. After mixing the continuous lubrication film-forming unit, surfactant and emulsifier, a second stirring treatment is performed to obtain an oil phase premix; S120. After heating the oil phase premix to the phase inversion temperature, add the aqueous phase and perform a third stirring treatment to obtain the base emulsion. S130. The low-friction sliding unit at the boundary is added to the base emulsion for a fourth stirring treatment to obtain the emulsion.

[0008] In one alternative embodiment, in the oil phase, the continuous lubrication film-forming unit comprises at least two of polyol esters, diesters, complex esters, and polyether esters; and / or the boundary low-friction slip unit comprises polyether-modified polysiloxane.

[0009] In an optional implementation, the mass ratio of the continuous lubrication film-forming unit to the boundary low-friction slip unit is 100:(0.2-8).

[0010] In an optional embodiment, in S120, the aqueous phase is deionized water; and / or the phase inversion temperature is 50-80°C; and / or after the third stirring treatment, the temperature is lowered to 10-30°C below the phase inversion temperature within 20-30 minutes; and / or the stirring speed of the third stirring treatment is 300-800 rpm.

[0011] In one alternative embodiment, the second stirring treatment takes 10-40 min; and / or the third stirring treatment takes 10-30 min; and / or the fourth stirring treatment takes 5-20 min.

[0012] In an optional embodiment, in S110, the surfactant includes a polyoxyethylene nonionic surfactant; and / or the emulsifier includes at least one of a polyoxyethylene nonionic emulsifier, a fatty acid ester emulsifier, a sorbitol ester emulsifier, and a glycerol ester emulsifier.

[0013] In an optional embodiment, in S200, the mass ratio of the continuous lubrication film-forming unit, the antistatic agent, and the slugging agent is 100:(1-20):(0.5-10); and / or the antistatic agent includes at least one of phosphate ester antistatic agents, polyether-type antistatic agents, and quaternary ammonium salt-type antistatic agents; and / or the slugging agent includes at least one of cationic slugging agents, nonionic slugging agents, and amphoteric slugging agents.

[0014] In an optional implementation, in S200, the settling time is 4-24 hours; the filtration process is a gradient filtration process; the gradient filtration process uses filter media with pore sizes of 5 μm and 1 μm in sequence.

[0015] In an optional embodiment, the particle size D50 of the solution-dyed fiber-specific highly dispersible FDY oil is 100-300 nm.

[0016] Secondly, this application provides a highly dispersible FDY oil agent specifically for solution-dyed fibers, which is prepared by any one of the preparation methods described above.

[0017] The beneficial effects of this application include at least the following: (1) This application constructs the main oil film with a continuous lubrication film-forming unit, strengthens the boundary friction reduction with a boundary low friction slip unit, obtains a highly dispersed base emulsion through phase inversion temperature emulsification, and then introduces boundary slip, antistatic and bundle functions in an additional manner, and combines a static and gradient filtration stabilization system to obtain a highly dispersed, low friction, wear-resistant and processing-stable FDY oil agent suitable for dope dyed fibers; (2) The oil phase premix is ​​heated to the phase inversion temperature and then the water phase is added and stirred. This is to take advantage of the fact that the interfacial tension is the lowest and the interfacial structure is the easiest to rearrange near the phase inversion temperature to form finer and more uniform emulsion droplets. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are only for explaining this application, but the implementation of this application is not limited thereto.

[0019] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this application pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; the amounts of experimental reagents used are, unless otherwise specified, the amounts used in conventional experimental operations; and the experimental methods used are, unless otherwise specified, conventional methods.

[0020] Compared to unbleached fibers, solution-dyed fibers have a more complex surface condition. The coloring components alter the surface energy, micro-roughness, and frictional behavior of the fiber surface. Therefore, uneven oiling can easily amplify localized friction and static electricity. FDY itself is a high-speed, continuous system with high stability requirements, making it easier for ordinary oil-based compounding methods to expose problems on solution-dyed fibers.

[0021] This application provides a crude oil-based FDY oiling agent and its preparation method. Addressing the issues of surface roughening and processing friction fluctuations in dope-dyed fibers, the method constructs the main oil film using a continuous lubrication film-forming unit, enhances boundary friction reduction using a low-friction boundary slip unit, obtains a highly dispersed base emulsion through phase inversion temperature emulsification, and then introduces boundary slip, antistatic, and clustering functions as an adjunct. Combined with a static and gradient filtration stabilization system, this results in a highly dispersed, low-friction, wear-resistant, and processing-stable FDY oiling agent suitable for dope-dyed fibers.

[0022] In a first aspect, embodiments of this application provide a method for preparing a highly dispersible FDY oil agent specifically for solution-dyed fibers, comprising: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200. Antistatic agent and bridging agent are added to the emulsion in sequence, and the first stirring treatment, standing treatment and filtration treatment are carried out in sequence to obtain a high dispersibility FDY oil agent for solution-dyed fibers. The oil phase includes a continuous lubrication film-forming unit and a boundary low-friction slip unit; S100 includes: S110. After mixing the continuous lubrication film-forming unit, surfactant and emulsifier, a second stirring treatment is performed to obtain an oil phase premix; S120. After heating the oil phase premix to the phase inversion temperature, add the aqueous phase and perform a third stirring treatment to obtain the base emulsion. S130. The low-friction sliding unit at the boundary is added to the base emulsion for a fourth stirring treatment to obtain the emulsion.

[0023] Specifically, in step S110, the continuous lubrication film-forming unit, surfactant, and emulsifier are mixed and stirred to create a homogeneous oil-phase premix with a stable interfacial precursor structure for subsequent phase-reversal emulsification. The continuous lubrication film-forming unit is typically composed of polyol esters, diesters, complex esters, and polyether esters. These components have different polarities, viscosities, and spreading behaviors. If they are not sufficiently and uniformly dispersed in the early stages, local compositional differences can easily occur during subsequent heating and emulsification, leading to asynchronous phase-reversal behavior in different regions and ultimately forming an emulsion with a wide particle size distribution. For example, the continuous lubrication film-forming unit can be selected from at least two of pentaerythritol ester, trimethylolpropane ester, neopentyl glycol ester, adipate ester, sebacic acid complex ester, and polyether-modified ester. The surfactant and emulsifier are pre-distributed into the oil phase at this stage, which facilitates the synchronous formation of rearrangeable interfaces throughout the system during subsequent heating. Only when the internal composition of the oil phase is sufficiently uniform and the surface-active components are fully pre-organized in the oil phase can the reduction of interfacial tension and interfacial rearrangement occur more consistently throughout the system when the phase inversion temperature is reached. This results in more synchronized droplet formation, smaller particle size and narrower distribution, and better stability of the base emulsion. The preferred mass ratio of the continuous lubrication film-forming unit, surfactant, and emulsifier is 100:(4-8):(1-3). The second stirring time is 10-40 min, which can both initially and uniformly stir the oil phase premix without over-stirring. The emulsifier includes at least one of polyoxyethylene nonionic emulsifier, fatty acid ester emulsifier, sorbitan ester emulsifier, and glyceryl ester emulsifier. This is beneficial for the formation of a base emulsion with smaller particle size and narrower distribution at the front end, and for the smooth introduction of the subsequent low-friction slip unit, antistatic agent, and clustering agent, thereby better achieving the high dispersibility, continuous film formation, and low-friction anti-wear performance pursued in this application.

[0024] Furthermore, the surfactant includes polyoxyethylene nonionic surfactants. Polyoxyethylene nonionic surfactants typically consist of lipophilic groups and polyoxyethylene segments. These polyoxyethylene segments exhibit strong hydration capabilities at lower temperatures, forming strong hydrogen bonds with water, thus resulting in significant hydrophilicity overall. As the temperature increases, the hydration layer around the polyoxyethylene segments is gradually disrupted, weakening their hydrophilicity and altering the overall hydrophilic-lipophilic balance of the molecule. It is this change in interfacial properties with temperature that distinguishes it from many common emulsifiers: it not only stabilizes the oil-water interface but also induces a state of significantly reduced interfacial tension and optimal interface rearrangement within a specific temperature range. This property is crucial for this application because the essence of phase inversion temperature emulsification is to utilize this temperature-sensitive behavior to form finer, more uniform droplets.

[0025] Furthermore, the preferred surfactant is a polyoxyethylene-type nonionic surfactant with a cloud point or phase inversion temperature characteristic. The cloud point reflects the temperature characteristic at which the system transitions from a homogeneous or transparent dispersed state to a turbid state after the hydration capacity of the polyoxyethylene-type nonionic surfactant decreases to a certain extent during heating. The phase inversion temperature reflects the ability of the surfactant to undergo a significant change in its hydrophilic-lipophilic balance during heating, leading to a shift in the system's emulsification tendency from one type to another. Surfactants with this property are not fixed-state emulsifiers, but rather temperature-driven interface modulators. When the system is heated to near this temperature range, the interfacial tension at the oil-water interface decreases, the surfactant arrangement at the interface becomes more flexible, and the interfacial film is more prone to curvature adjustment and rearrangement. This is more conducive to refining the oil phase into smaller, narrower-distributed droplets. If ordinary emulsifiers without cloud point or phase inversion temperature characteristics are used, the emulsification of the system relies more on mechanical stirring itself, making it difficult to fully utilize the low interfacial tension to assist in fine emulsification. Therefore, the resulting base emulsion often has a larger particle size and wider distribution, and the subsequent film uniformity is relatively poor. Because solution-dyed fibers are more sensitive to the uniformity of oil film formation, their surfaces are more prone to increased micro-roughness and localized friction peaks due to the influence of coloring components, carriers, and processing. This necessitates that the base emulsion of the oil agent must have as small and uniformly distributed droplets as possible. Only in this way can the continuous lubrication film-forming units spread more evenly on the fiber surface, forming a continuous main oil film and providing a stable bearing layer for the subsequent addition of boundary low-friction slip units. If the upstream emulsion structure is not fine or uniform enough, even with the subsequent addition of boundary low-friction slip units, antistatic agents, and bridging agents, localized enrichment, localized oil deficiency, or friction fluctuations may still occur on the fiber surface.

[0026] Preferably, step S120 is the core step of this application. Heating the oil-phase premix to the phase inversion temperature before adding the aqueous phase and stirring utilizes the fact that the interfacial tension is lowest and the interfacial structure is most easily rearranged near the phase inversion temperature to form finer and more uniform droplets. For polyoxyethylene nonionic surfactants, as the temperature increases, the hydration capacity of the polyoxyethylene segments decreases, the hydrophilicity of the surfactant weakens, and the spontaneous curvature of the system changes accordingly. Around a certain temperature range, a phase inversion phenomenon occurs, where one emulsification tendency changes to another. Within this temperature range, the interfacial tension at the oil-water interface decreases significantly, the energy cost of forming a new interface is reduced, and the droplets are more easily refined. If mechanical emulsification is performed directly at normal temperatures, the system relies more on mechanical shearing to disperse the oil droplets, resulting in coarser droplets, wider distribution, and less uniform interfacial structure. Adding the aqueous phase and emulsifying near the phase inversion temperature is equivalent to using the system's own interfacial rearrangement ability to assist in droplet refinement, thus obtaining a finer, more uniform, and stable base emulsion. The phase inversion temperature is 50-80℃. On the one hand, the temperature is high enough that the hydrophilic-lipophilic balance of the surfactant has changed significantly, allowing it to truly enter phase inversion. On the other hand, it is not high enough to cause significant thermal instability or volatilization risks to the ester-based main oil phase, polyether-modified components, or low-friction units of interest in subsequent processing. If the temperature is below this range, the hydration state of the surfactant does not change sufficiently, phase inversion is not obvious, and the system is still closer to ordinary thermal emulsification, making it difficult to fully utilize the low interfacial tension to refine the droplets. If the temperature is above this range, although phase inversion may still occur, it is more likely to lead to problems such as component thermal degradation, volatilization loss, excessive interfacial disturbance, and instability in subsequent processes. If the aqueous phase is added too early, the system will only undergo conventional emulsification at normal temperatures, making it difficult to fully utilize the low interfacial tension advantage of the phase inversion temperature. However, if the aqueous phase is added after the phase inversion temperature is reached, the interface is in a state where it is most easily reconstructed when the aqueous phase enters the system. A stable and uniform new interface can be formed between the oil droplets and the aqueous phase more quickly. This can make the droplet formation efficiency higher and the system more likely to obtain a highly dispersed emulsion structure, rather than simply relying on high shear to forcibly disperse it.

[0027] Preferably, the third stirring speed is 300-800 rpm. Near the phase inversion temperature, although the interfacial tension has decreased and the system is more likely to form fine droplets, a certain amount of mechanical energy is still required for the aqueous phase to be uniformly distributed in the oil phase and form a new interface. Within the 300-800 rpm range, there is sufficient mixing and dispersion capacity without turning the system from spontaneous rearrangement and refinement based on phase inversion interfaces into pure shear-driven fragmentation. The third stirring time is 10-30 minutes, which is sufficient for the added aqueous phase to fully undergo the processes of dispersion, interfacial morphology, and structural rearrangement. After the third stirring process, the temperature is lowered to 10-30°C below the phase inversion temperature within 20-30 minutes. This is because if the temperature remains in the phase inversion temperature range for too long, the already formed fine droplets may continue to undergo interfacial rearrangement, droplet coalescence, local coarsening, or particle size drift, causing the refining effect obtained through the phase inversion path to be gradually lost. Therefore, the temperature needs to be lowered to 10-30°C below the phase inversion temperature within 20-30 minutes. This ensures that the cooling is fast enough to preserve the structure of the already formed fine droplets, while preventing excessive local temperature differences, sudden viscosity changes, or uneven shrinkage due to rapid cooling. This is beneficial for improving storage stability, dilution stability, and resistance to disturbances when adding subsequent components.

[0028] Furthermore, the aqueous phase includes deionized water, which provides a less turbulent aqueous environment. In this application, the front-end emulsification relies on the interfacial rearrangement process between surfactants and emulsifiers near the phase inversion temperature. This process is highly sensitive to the electrolyte content, impurity ion concentration, and aqueous phase purity in the system. If ordinary industrial water or hard water is used, common metal ions such as calcium, magnesium, and iron, as well as other inorganic salts, readily coordinate, associate, or shield with surfactants, antistatic agents, or emulsifiers in the system. This alters the hydration state and interfacial adsorption behavior of the surfactants, leading to phase inversion temperature drift, coarser droplet size, wider droplet size distribution, and even localized flocculation, precipitation, or stratification. When antistatic agents and clustering agents are subsequently added, the system is more prone to instability if the base emulsion itself is already affected by ionic impurities. Adding 0.5-5 wt% of an inversion agent to deionized water can improve the inversion emulsification process. Suitable inversion agents include ethylene glycol, propylene glycol, butanediol, polyethylene glycol, glycerin, and sorbitol. These agents not only alter the hydration of the water phase with the polyethylene oxide chain but also change the polarity and viscosity of the aqueous phase itself. This makes the inversion behavior of the surfactant more gradual and controllable, and the inversion temperature easier to adjust. This prevents the system from abruptly entering the inversion state, thus promoting droplet refinement and narrowing of the particle size distribution.

[0029] Preferably, in step S130, the boundary low-friction slip unit is added and stirred after the base emulsion is formed. The boundary low-friction slip unit is preferably a polyether-modified polysiloxane, which provides boundary lubrication and low-friction slip when the metal parts that come into contact with the fiber bundle during fiber processing come into contact with each other. The reason for not adding it together with the continuous lubrication film-forming unit in the early stage is that polyether-modified polysiloxane usually has strong interfacial activity and special spreading behavior. If it is added before the base emulsion is formed, it is easy to disrupt the droplet formation process that originally relies on the phase inversion path, which leads to insufficient droplet refinement, uneven interfacial composition, and widened particle size distribution. Adding it later means that the continuous lubrication film-forming unit first establishes a stable main droplet structure through phase inversion emulsification, and then the polyether-modified polysiloxane is distributed on the droplet surface or subsequent oil film interface on the basis of the already formed emulsion, thereby constructing the boundary low-friction slip layer. A continuous lubrication film-forming unit is responsible for forming the main oil film, while a low-friction boundary slip unit is responsible for improving the boundary contact state. This approach maintains the high dispersibility and film-forming continuity of the base emulsion while fully leveraging the role of polyether-modified polysiloxane in reducing boundary friction, minimizing guide wire wear, and reducing filament breakage. The fourth stirring treatment lasts for 5-20 minutes, ensuring that the low-friction boundary slip unit fully expands and disperses throughout the emulsion without causing localized foaming or interface re-disturbance.

[0030] Furthermore, the oil phase includes a continuous lubrication film-forming unit and a boundary low-friction slip unit. The continuous lubrication film-forming unit is mainly for forming the main oil film on the fiber surface. During high-speed guiding, drawing, and winding of solution-dyed fibers, the fiber surface needs a lubricating layer that can continuously cover, maintain its film, and is not easily pulled away locally. Otherwise, even if some locations are momentarily slippery, uneven overall coverage will lead to increased local friction. The continuous lubrication film-forming unit has good wettability, spreadability, and film-holding properties. It can spread out on the fiber surface to form a continuous liquid film or semi-continuous film, thereby wrapping up the roughness and undulations of the fiber surface, reducing the overall friction level, and providing a stable bearing base for subsequent functional components. However, continuous lubrication film-forming units alone are insufficient. Compared to unbleached fibers, solution-dyed fibers are more prone to surface micro-roughening due to pigments, masterbatches, and their carriers. In actual processing, this can lead to high friction peaks at local contact points, especially at the fiber-metal guides, guide needles, heated rollers, or winding points. These areas experience high local pressure and slip velocity, and even if the main oil film exists, it may be thinned or even fail locally at the micro-contact boundaries. Therefore, low-friction boundary slip units are needed to reduce shear resistance, improve instantaneous slip conditions, and weaken friction peaks at the fiber-metal micro-contact interface, thereby reducing fuzz, breakage, and component wear. In the preparation method, the continuous lubrication film-forming unit first participates in the phase reversal temperature emulsification to form a stable and fine base emulsion, initially creating a uniform droplet structure. The low-friction boundary slip unit is added subsequently to avoid interfering with the formation of the base emulsion and to distribute as much as possible to the subsequent oil film interface and boundary contact layer.

[0031] Preferably, the mass ratio of continuous lubrication film-forming units to boundary low-friction slip units is 100:(0.2-8). A larger number of continuous lubrication film-forming units can stably form a continuous and uniform main lubrication film, thereby ensuring overall lubrication and film retention capabilities. The amount of boundary low-friction slip units is controlled within the range of 0.2-8, which is sufficient at the fiber-metal interface to effectively influence local slip behavior, reduce local friction peaks and wear tendency, and will not be excessively enriched at the interface, nor will it significantly weaken the subsequent effects of antistatic agents and bundlers. This is beneficial for maintaining fiber bundle stability and overall processing consistency. It can also reduce the risks of migration, deposition, and high-temperature residue caused by excessive low surface energy slip components, thereby improving the stability and cleanliness of the oil under actual industrial processing conditions.

[0032] Preferably, in step S200, the antistatic agent and the clustering agent are added sequentially. This is because these two types of components have different adsorption behaviors, polar characteristics, and modes of action at the interface. Adding them simultaneously can easily lead to excessively high local concentrations, intensified interfacial competition, and even local flocculation or enrichment. Adding them sequentially allows each type of component to gradually redistribute and reach adsorption equilibrium in the system, thereby reducing local instability, resulting in a more uniform distribution of functional components, higher batch consistency, and smaller fluctuations in friction, static electricity, and clustering performance during subsequent use. The settling treatment allows the system to gradually recover from the dynamic disturbance state caused by stirring to a more stable state. After stirring, local concentration gradients, microbubbles, and functional components that have not yet reached adsorption equilibrium may still exist in the system. By settling for 4-24 hours, the antistatic agent, clustering agent, and low-friction boundary slip units have more time to redistribute themselves at the droplet interface and in the oil film precursor structure. Bubbles and local disturbances can be eliminated, allowing the system to transition from a temporarily dispersed state to a quasi-stable structural state. This results in better storage stability of the finished oil, reduced coarse particles and local enrichment, smoother subsequent filtration, and higher oiling uniformity. Although the main emulsion has formed well after settling, a small amount of coarse particles, locally undispersed particles, or functional component enrichments may still remain in the system. These substances can easily form localized oil spots, increase contamination of guide components, and even become friction hotspots and deposit sources during actual oiling and spinning. By employing filtration, preferably gradient filtration using filter media with pore sizes of 5μm and 1μm sequentially, these particles can be removed without significantly damaging the main emulsion structure. This improves the overall homogeneity of the system, reduces the risk of clogging in the oiling system, minimizes coarse particle deposition and equipment contamination during processing, and enhances the cleanliness and stability of the oil.

[0033] Preferably, the mass ratio of the continuous lubrication film-forming unit, antistatic agent, and slugging agent is 100:(1-20):(0.5-10). If the amount of antistatic agent is lower than this range, the amount of antistatic agent is insufficient, making it difficult to form a continuous or sufficiently dense conductive and dissipative interface, resulting in an insignificant static control effect. If it is higher than this range, it is prone to competing for adsorption with the main oil film and the subsequently added boundary low-friction slip components, changing the interface composition, or even weakening the continuity of the oil film, increasing emulsion instability, or making the fiber surface too polarized, affecting the low-friction slip effect. Antistatic agents include at least one of phosphate ester antistatic agents, polyether antistatic agents, and quaternary ammonium salt antistatic agents. Phosphate ester antistatic agents have high polarity and often have good antistatic effects in oil-based systems. They also have good compatibility with many lubrication systems and can form an interface layer on the fiber surface that facilitates charge dissipation. Polyether antistatic agents are generally milder, have good compatibility, and also have certain lubrication synergy. They can improve antistatic properties without significantly damaging the main oil film. Quaternary ammonium salt antistatic agents can reduce surface resistance and improve charge release efficiency. If the amount of bubbling agent is too low, it will not be sufficient to establish the necessary bundle stability between the fibers; if the amount is too high, it will cause the fiber surface to adhere too much, and may even weaken the already established low-friction state, causing the fibers to exhibit problems such as stiffness, binding, or poor slippage. Bubbling agents include at least one of cationic, nonionic, and amphoteric bubbling agents. Cationic bubbling agents usually have a more significant effect on improving fiber cohesion and bundle stability. Nonionic bubbling agents are usually milder, have less disturbance to the main emulsion structure, and have better compatibility. Amphoteric bubbling agents can provide a certain degree of bundle stability without exhibiting excessively strong single electrical properties at the interface.

[0034] Furthermore, after adding the antistatic agent and the chelating agent in step S200, defoamers, preservatives, chelating agents and other additives may also be added as needed, without specific limitations.

[0035] Preferably, the particle size D50 of the high-dispersibility FDY oil agent for solution-dyed fibers is 100-300nm, indicating that the base emulsion has higher dispersibility and better spreading ability. The continuous lubrication film-forming unit is more likely to be evenly distributed on the fiber surface. The low-friction sliding unit at the boundary is also more likely to play a role on the basis of the existing fine droplets after being added. The subsequent introduction of antistatic agents and bundlers is also less likely to be amplified into unstable points by local coarse-grained structures.

[0036] Secondly, this application provides a highly dispersible FDY oiling agent specifically for solution-dyed fibers. This highly dispersible FDY oiling agent for solution-dyed fibers is prepared using any one of the preparation methods described above. Therefore, it possesses all the beneficial effects of the preparation method for the highly dispersible FDY oiling agent for solution-dyed fibers, which will not be elaborated further here. Example 1

[0037] This embodiment provides a highly dispersible FDY oil agent specifically for solution-dyed fibers, and its preparation method includes the following steps: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200, quaternary ammonium salt antistatic agent and cationic bridging agent are added to the emulsion in a continuous lubrication film-forming unit with a mass ratio of antistatic agent to bridging agent of 100:20:10. The mixture is then subjected to a first stirring treatment, a standing treatment for 24 hours, and a gradient filtration treatment using filter media with pore sizes of 5μm and 1μm to obtain a high-dispersibility FDY oil agent for dope dyed fibers. The oil phase comprises a continuous lubrication film-forming unit and a boundary low-friction slip unit, with a mass ratio of 100:8; S100 comprises: S110. The continuous lubrication film-forming unit pentaerythritol ester and trimethylolpropane ester, polyoxyethylene nonionic surfactant and polyoxyethylene nonionic emulsifier are mixed at a mass ratio of 100:8:3 and then subjected to a second stirring treatment for 40 minutes to obtain an oil phase premix. S120. After heating the oil phase premix to the phase inversion temperature, add deionized water and perform a third stirring treatment at 800 rpm for 30 min. After the third stirring treatment, cool down to 30°C below the phase inversion temperature within 30 min to obtain the base emulsion. S130. Add the low-friction sliding unit polyether-modified polysiloxane to the base emulsion and perform a fourth stirring treatment for 20 minutes to obtain the emulsion. Example 2

[0038] This embodiment provides a highly dispersible FDY oil agent specifically for solution-dyed fibers, and its preparation method includes the following steps: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200, polyether-type antistatic agent and nonionic bridging agent are added to the emulsion in sequence according to the continuous lubrication film-forming unit and the mass ratio of antistatic agent to bridging agent is 100:1:0.5. The mixture is then subjected to the first stirring treatment, standing treatment for 4 hours, and gradient filtration treatment using filter media with pore sizes of 5μm and 1μm to obtain a high-dispersibility FDY oil agent for dope dyed fibers. The oil phase comprises a continuous lubrication film-forming unit and a boundary low-friction slip unit, with a mass ratio of 100:0.2; S100 comprises: S110. The continuous lubrication film-forming unit, neopentyl glycol ester, adipate ester, polyoxyethylene nonionic surfactant and fatty acid ester emulsifier are mixed at a mass ratio of 100:4:1 and then subjected to a second stirring treatment for 10 minutes to obtain an oil phase premix. S120. After heating the oil phase premix to the phase inversion temperature, add deionized water and perform a third stirring treatment at 300 rpm for 10 min. After the third stirring treatment, cool down to 10°C below the phase inversion temperature within 20 min to obtain the base emulsion. S130. Add the low-friction sliding unit polyether-modified polysiloxane to the base emulsion and perform a fourth stirring treatment for 5 minutes to obtain the emulsion. Example 3

[0039] This embodiment provides a highly dispersible FDY oil agent specifically for solution-dyed fibers, and its preparation method includes the following steps: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200, phosphate ester antistatic agent and amphoteric bridging agent are added to the emulsion in a continuous lubrication film-forming unit with an antistatic agent to bridging agent mass ratio of 100:10:5. The mixture is then subjected to a first stirring treatment, a standing treatment for 4 hours, and a gradient filtration treatment using filter media with pore sizes of 5μm and 1μm to obtain a high-dispersibility FDY oil agent for solution-dyed fibers. The oil phase comprises a continuous lubrication film-forming unit and a boundary low-friction slip unit, with a mass ratio of 100:4; S100 comprises: S110. Sebacic acid ester, fatty acid complex ester, polyoxyethylene nonionic surfactant with cloud point or phase inversion temperature characteristics, and fatty acid ester emulsifier are mixed at a mass ratio of 100:4:1 and then subjected to a second stirring treatment for 30 minutes to obtain an oil phase premix. S120. After heating the oil phase premix to the phase inversion temperature, add deionized water and perform a third stirring treatment at 500 rpm for 20 min. After the third stirring treatment, cool down to 20°C below the phase inversion temperature within 25 min to obtain the base emulsion. S130. Add the low-friction sliding unit polyether-modified polysiloxane to the base emulsion and perform a fourth stirring treatment for 10 minutes to obtain the emulsion. Example 4

[0040] This embodiment provides a highly dispersible FDY oil agent specifically for solution-dyed fibers, and its preparation method includes the following steps: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200, phosphate ester antistatic agent and amphoteric bridging agent are added to the emulsion in a continuous lubrication film-forming unit with an antistatic agent to bridging agent mass ratio of 100:10:5. The mixture is then subjected to a first stirring treatment, a standing treatment for 4 hours, and a gradient filtration treatment using filter media with pore sizes of 5μm and 1μm to obtain a high-dispersibility FDY oil agent for solution-dyed fibers. The oil phase comprises a continuous lubrication film-forming unit and a boundary low-friction slip unit, with a mass ratio of 100:4; S100 comprises: S110. Sebacic acid ester, fatty acid complex ester, polyoxyethylene nonionic surfactant with cloud point or phase inversion temperature characteristics, and fatty acid ester emulsifier are mixed at a mass ratio of 100:4:1 and then subjected to a second stirring treatment for 30 minutes to obtain an oil phase premix. S120. After heating the oil phase premix to the phase inversion temperature, add deionized water containing 5 wt% glycerol and perform a third stirring treatment at 500 rpm for 20 min. After the third stirring treatment, cool down to 20°C below the phase inversion temperature within 25 min to obtain the base emulsion. S130. Add the low-friction sliding unit polyether-modified polysiloxane to the base emulsion and perform a fourth stirring treatment for 10 minutes to obtain the emulsion.

[0041] Comparative Example 1 This comparative example provides a highly dispersible FDY oil agent specifically for solution-dyed fibers. The preparation method differs from that in Example 1 in that the continuous lubrication film-forming unit, the boundary low-friction slip unit, the antistatic agent, the slugging agent, the surfactant, the emulsifier, and the aqueous phase are mixed and emulsified in one step, instead of being added in stages.

[0042] Comparative Example 2 This comparative example provides a highly dispersible FDY oil agent for solution-dyed fibers. The preparation method differs from that of Example 1 in that deionized water is added at room temperature in step S120.

[0043] Comparative Example 3 This comparative example provides a highly dispersible FDY oil agent for solution-dyed fibers. The preparation method is different from that of Example 1 in that step S130 is omitted, and the low-friction sliding unit polyether-modified polysiloxane is added in step S110.

[0044] Comparative Example 4 This comparative example provides a highly dispersible FDY oil agent for solution-dyed fibers. The preparation method differs from that of Example 1 in that step S130 is omitted and no boundary low-friction slip unit polyether-modified polysiloxane is added.

[0045] Comparative Example 5 This comparative example provides a highly dispersible FDY oil agent for solution-dyed fibers. The preparation method differs from that of Example 1 in that step S200 does not include static treatment and filtration.

[0046] Comparative Example 6 This comparative example provides a highly dispersible FDY oil agent for solution-dyed fibers. The preparation method differs from that in Example 1 in that the mass ratio of the continuous lubrication film-forming unit and the boundary low-friction slip unit is 100:20.

[0047] This application has undergone multiple experiments, and some of the test results are presented here for reference to further describe the invention in detail. The following is a detailed description in conjunction with specific embodiments.

[0048] Performance testing Emulsion particle size and distribution test: Take the mother liquor of each sample oil, dilute it to 10wt% according to the concentration used, let it stand at 25℃ for 30min, and then use a dynamic light scattering particle size analyzer to test the median particle size D50 and polydispersity index PDI. Each sample is tested in parallel: 3 times, and the average value is taken. Centrifugation stability test: Take 50 mL of each sample and centrifuge at 3000 rpm for 30 min. Record whether stratification, oil floating or sedimentation occurs, and express the degree of stratification as a percentage of stratification height. Dilution stability test: Dilute each sample to 10 wt%, place at 25℃ for 24 h, observe for stratification, flocculation, and oil floating, and record the status for 24 h. For the hard water stability test, each sample was diluted to 10 wt%, and then hard water was added to make the CaCO3 concentration 200 ppm. The samples were placed at 25°C for 24 h and the presence of flocculation, turbidity or precipitation was observed. The test results are shown in Table 1.

[0049] Table 1 As can be seen from Table 1, the performance of Examples 1-4 is superior to that of Comparative Examples 1-6, especially Example 4, indicating that the phase inversion aid can improve the interfacial rearrangement under the phase inversion window, resulting in more complete droplet refinement. Comparative Example 1 has the worst D50 and PDI, and the most obvious centrifugal stratification, dilution oil removal, and hard water flocculation, indicating that the boundary low-friction slip unit, antistatic agent, and clustering agent participate in interfacial competition too early, destroying the formation of the basic emulsion. The particle size of Comparative Example 2 is significantly larger, indicating that the phase inversion temperature emulsification in this application is not a normal heating step, but an important prerequisite for the formation of fine droplets. The particle size and PDI of Comparative Example 3 are inferior to those of Examples 1, 3, and 4, indicating that the addition of the boundary low-friction slip unit is necessary. The PDI, centrifugal stratification, and stability of Comparative Example 5 are slightly worse, indicating that settling and filtration can effectively remove coarse particles and rich aggregates, improving the stability of the finished product. In Comparative Example 6, the boundary low-friction slip unit is excessive, and the particle size and PDI are worse, indicating that this component cannot be added indefinitely.

[0050] Dynamic friction coefficient test: The fiber-metal pin friction test device was used. After the solution-dyed polyester FDY filament was oiled, it was passed through the stainless steel test pin with a fixed tension and speed to test the fiber-metal dynamic friction coefficient μ. The average value and fluctuation value CV (%) were calculated by recording 10 measurements. Oil film uniformity test: The oiled fiber bundle is divided into 10 segments of equal length, and the surface oil content is measured for each segment. The coefficient of variation (CV) is calculated. The smaller the CV, the more uniform the oil film. Guide wire wear test: After oiling each sample, the wire bundle was continuously rubbed on a standard stainless steel guide wire pin for 4 hours. The wear loss weight (mg) of the guide wire pin was tested and the surface scratches were observed. The test results are shown in Table 2.

[0051] Table 2 As shown in Table 2, the performance of the examples is generally good. The friction coefficient and wear of Comparative Examples 1-2 are significantly increased, indicating that the preparation methods used in Comparative Examples 1-2 lead to uneven film formation, resulting in increased friction peaks and aggravated wear. Although the average friction coefficient of Comparative Example 3 is lower than that of Comparative Example 4, the friction fluctuation is still significantly greater than that of Examples 1 and 3, and the guide wire wear is also greater, indicating that the timing and order of adding the boundary low-friction slip unit are crucial. The oil film uniformity of Comparative Example 4 is acceptable, but the friction coefficient and wear are significantly worse, indicating that the boundary low-friction slip unit is essential for reducing boundary contact wear. Comparative Example 6 has the lowest friction coefficient, but the friction fluctuation CV and wear weight loss are significantly increased. This shows that more boundary low-friction slip units are not necessarily better; excessive units, while reducing average friction, can disrupt the continuity of the main oil film and interface stability, leading to more unstable processing.

[0052] Electrostatic test: The electrostatic voltage (kV) of the oiled fiber bundle was tested under constant temperature and humidity conditions. Each sample was tested 5 times and the average value was taken. Bundle stability test: Pass the filament bundle through a standard tension path and record the filament bundle spread angle and bundle stability score (out of 10, the higher the score, the more stable). The test results are shown in Table 3.

[0053] Table 3 As shown in Table 3, Examples 1, 3, and 4 exhibited significantly lower electrostatic voltages, smaller bundle spread angles, and higher bundle stability scores. This indicates that adding antistatic agents and bundle accumulators after the formation of a highly dispersed base emulsion allows for a more uniform distribution of these two functional components on the emulsion and fiber surfaces, thereby achieving both better charge control and bundle stability. While Example 2 still outperformed most comparative examples, its electrostatic and bundle performance was relatively weaker, likely due to less than optimal process parameters and formulation. Comparative Examples 1-2 showed significantly higher electrostatic voltages, indicating that the preparation methods used in Comparative Examples 1-2 impaired the effective distribution of functional components within the system. Although Comparative Example 3 retained the antistatic and bundle system, its electrostatic and bundle performance was inferior to the examples due to the disturbance of the base emulsion structure. Comparative Example 6 exhibited lower friction, but its bundle spread angle increased and bundle stability score decreased, suggesting that excessive low-friction slip units at the boundaries can cause over-slippage, disrupting bundle stability.

[0054] Filament and breakage test: Under simulated winding conditions, run continuously for 8 hours and record the number of filaments and breakages per 100,000 meters of filament bundle; Deposition / cleanliness test: Add an equal amount of sample to a hot metal plate at 180℃, keep for 30 min, and weigh the residual sediment (mg) after cooling; at the same time, observe the coarse particle condition before and after filtration; The results are shown in Table 4.

[0055] Table 4 As shown in Table 4, Examples 1, 3, and 4 exhibited low hot plate deposition, fewer coarse particles, fewer fibrous strands, and fewer broken ends. This indicates that the proposed solution not only resulted in a finer emulsion structure but also effectively reduced coarse particles and localized enrichment through settling and gradient filtration, thereby reducing deposition at high-temperature contact points and abnormal friction points during processing. Example 4, in particular, demonstrates that the phase-inversion agent system with added glycerol not only improved particle size but also further reduced the risk of coarse particles and deposition. Comparative Examples 1-2 showed the worst performance in terms of coarse particle count, deposition amount, fibrous strands, and broken ends, indicating that even with antistatic agents and clustering agents, contamination and instability during processing are difficult to avoid if the basic emulsion structure is poor. Comparative Example 3 showed a significant difference compared to Example 1, indicating that the addition of low-friction boundary slip units leads to localized enrichment and increased coarse particles, thus increasing deposition and fibrous strands. Although the deposition in Comparative Example 4 was acceptable, the number of fibrous strands and broken ends was still significantly higher than in Examples 1-4, indicating insufficient boundary friction control. The significantly increased coarse particle number, deposition, and fibrous material in Comparative Example 5 indicate that settling and gradient filtration are key steps to ensure cleanliness and stability. Although Comparative Example 6 has a low average friction, the significant increase in hot plate deposition and breakage suggests that excessive low-friction boundary slip units are more prone to migration and accumulation, which is detrimental to long-term stable operation. The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for preparing a highly dispersible FDY oil agent specifically for solution-dyed fibers, characterized in that, include: S100. Add the aqueous phase to the oil phase and stir to obtain an emulsion; S200. The antistatic agent and the flocculating agent are added to the emulsion in sequence, and the first stirring treatment, the standing treatment and the filtration treatment are carried out in sequence to obtain the high dispersibility FDY oil agent for solution-dyed fibers. The oil phase includes a continuous lubrication film-forming unit and a boundary low-friction slip unit; S100 includes: S110. The continuous lubrication film-forming unit, surfactant and emulsifier are mixed and then subjected to a second stirring treatment to obtain an oil phase premix; S120. After heating the oil phase premix to the phase inversion temperature, add the aqueous phase and perform a third stirring treatment to obtain the base emulsion. S130. The boundary low-friction sliding unit is added to the base emulsion for a fourth stirring treatment to obtain the emulsion.

2. The preparation method according to claim 1, characterized in that, In the oil phase, The continuous lubrication film-forming unit comprises at least two of polyol esters, diesters, complex esters, and polyether esters; and / or The boundary low-friction slip unit comprises polyether-modified polysiloxane.

3. The preparation method according to claim 2, characterized in that, The mass ratio of the continuous lubrication film-forming unit to the boundary low-friction slip unit is 100:(0.2-8).

4. The preparation method according to claim 1, characterized in that, In S120, The aqueous phase is deionized water; and / or The reverse rotation temperature is 50-80℃; and / or After the third stirring process is completed, the temperature is lowered to 10-30°C below the phase reversal temperature within 20-30 minutes; and / or The rotation speed of the third stirring process is 300-800 rpm.

5. The preparation method according to claim 1, characterized in that, The second stirring treatment time is 10-40 min; and / or The third stirring process takes 10-30 minutes; and / or The fourth stirring process takes 5-20 minutes.

6. The preparation method according to claim 1, characterized in that, In S110, Surfactants include polyoxyethylene nonionic surfactants; and / or The emulsifier includes at least one of polyoxyethylene nonionic emulsifiers, fatty acid ester emulsifiers, sorbitol ester emulsifiers, and glycerol ester emulsifiers.

7. The preparation method according to claim 1, characterized in that, In S200, The continuous lubrication film-forming unit, the antistatic agent, and the slugging agent have a mass ratio of 100:(1-20):(0.5-10); and / or The antistatic agent includes at least one of phosphate ester antistatic agents, polyether antistatic agents, and quaternary ammonium salt antistatic agents; and / or The bundler includes at least one of cationic bundlers, nonionic bundlers, and amphoteric bundlers.

8. The preparation method according to claim 1, characterized in that, In S200, The settling time is 4-24 hours; The filtering process is a gradient filtering process; The gradient filtration process uses filter media with pore sizes of 5μm and 1μm in sequence.

9. The preparation method according to claim 1, characterized in that, In S200, The particle size D50 of the solution-dyed fiber-specific highly dispersible FDY oil is 100-300 nm.

10. A highly dispersible FDY oiling agent specifically for solution-dyed fibers, characterized in that, The solution-dyed fiber-specific highly dispersible FDY oil agent is prepared using the preparation method described in any one of claims 1-9.

Images