Special POY (pre-oriented yarn) oiling agent for spinning and preparation method thereof

Abstract

The invention provides a special POY (pre-oriented yarn) oil agent for spinning and a preparation method thereof, and the preparation method comprises the following steps: preparing a water phase from raw materials including a shear thickening agent and polyethylene glycol; preparing an oil phase from raw materials including a smoothing agent, an emulsifier, an antistatic agent and a bundling agent; dropwise adding the oil phase into the water phase, and uniformly emulsifying to obtain a POY oiling agent; wherein the shear thickening agent is modified silicon dioxide nanoparticles modified by an acrylic copolymer. The POY oil agent can maintain the viscosity temperature under the conditions of high temperature and high shear force, can be stably stored under the condition of low temperature, and is not easy to layer and precipitate after being stored for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical materials, and in particular to a POY oil agent special for spinning and a preparation method thereof. Background Art

[0002] Polyester is made from purified terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (MEG) through esterification or transesterification reaction and then polycondensation reaction to produce polyethylene terephthalate (PET). PET is then spun and post-processed to produce fibers.

[0003] Polyester products primarily include POY (pre-oriented yarn), FDY (fully drawn yarn), and DTY (draw textured yarn). Polyester POY pre-oriented yarn is a partially oriented wound yarn produced through a high-speed spinning process (spinning speeds of 3000 to 3600 m / min). Polyester POY enjoys a high market share due to its high degree of orientation, high elongation at break, low crystallinity, structural stability, and excellent post-processing properties.

[0004] Since synthetic fibers do not have the natural gum and oil film that natural fibers have, they have poor hygroscopicity and are non-conductive. Therefore, static electricity is easily generated due to constant friction during the spinning process. Additives must be used to prevent or eliminate static electricity accumulation, and at the same time give the fibers softness, smoothness and other properties to enable them to pass through the subsequent processes smoothly. Such additives are collectively called fiber spinning oils.

[0005] POY finish is an essential chemical additive in the production of polyester pre-oriented yarns. It is primarily used to improve the fiber's spinnability, antistatic properties, smoothness, and subsequent processing performance. POY finishes are typically formulated from a combination of functional components, primarily including the following: a smoothing agent, a core component whose properties directly influence the finish's effectiveness. Common smoothing agents include mineral oils, fatty acid esters, polyol esters, and polyethers; antistatic agents, primarily anionic, cationic, or nonionic surfactants such as alkyl phosphates and sodium alkyl sulfonate derivatives, which are used to reduce static electricity accumulation during fiber processing; emulsifiers such as stearates, sorbitan fatty acid esters, and polyoxyethylene ethers, which ensure a stable emulsion of the finish in water; and sizing agents such as lauryl polyoxyethylene ether or sulfated castor oil, which enhance interfiber cohesion and reduce linting and breakage. POY finishes may also be supplemented with other functional components to improve heat resistance, dispersibility, stability, and other properties.

[0006] Currently, most existing POY finishes are oil-in-water emulsions. One drawback is that, under high-temperature and high-shear processing conditions, the viscosity of the POY finish decreases significantly, making it difficult to form a uniform oil film on the fiber surface. This increases friction between the fiber and the equipment, leading to linting and end breakage. This viscosity reduction is due to two factors: first, the enhanced thermal motion of molecules at high temperatures weakens intermolecular forces (such as van der Waals forces and hydrogen bonds), resulting in increased fluidity and decreased viscosity. Second, high shear can break up emulsion droplets, disrupting the emulsification process, leading to oil-water separation and a sudden drop in viscosity. Therefore, if the viscosity of emulsion-based polyester POY finishes could be controlled to maintain stability under high-temperature and high-shear processing conditions, it would help improve the spinning performance of POY polyester fibers and prevent or reduce linting and end breakage. Summary of the Invention

[0007] One of the problems solved by the present invention is how to provide a POY oil agent for spinning that can maintain stable viscosity under high temperature and high shear process conditions.

[0008] In order to solve at least one of the above problems, the present invention provides a method for preparing a POY oil agent for spinning, the preparation method comprising: S100, preparing an aqueous phase using raw materials including a shear thickener and polyethylene glycol; S200, preparing an oil phase using raw materials including a smoothing agent, an emulsifier, an antistatic agent, and a sizing agent; S300, adding the oil phase dropwise into the water phase and emulsifying uniformly to obtain a POY oil solution; The shear thickener is modified silica nanoparticles modified with acrylic acid copolymer.

[0009] In the above technical solution, the acrylic copolymer modification treatment is carried out by mixing silica nanoparticles with organic matter including acrylic acid monomers and / or acrylate monomers, and obtaining modified silica nanoparticles through polymerization reaction under the action of an initiator.

[0010] In the above technical solution, the shear thickener includes a first shear thickener and a second shear thickener, the first shear thickener is a first modified silica nanoparticle modified by a first acrylic copolymer, and the second shear thickener is a second modified silica nanoparticle modified by a second acrylic copolymer; wherein, when the first acrylic copolymer and the second acrylic copolymer are prepared separately, the raw material components and / or raw material ratios used are different.

[0011] In the above technical solution, the weight average molecular weight of the first acrylic copolymer is less than the weight average molecular weight of the second acrylic copolymer; and / or the thermal decomposition temperature of the first acrylic copolymer is less than the thermal decomposition temperature of the second acrylic copolymer; and / or in the shear thickener, the mass ratio of the first shear thickener to the second shear thickener is (150-200):100.

[0012] In the above technical solution, the preparation method of the first shear thickener includes: S410, mixing Tween 60 and silica nanoparticles in water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a first suspension; S420. In an ice-water bath, azobisisobutyronitrile, methacrylic acid, methyl methacrylate, and butyl acrylate are mixed in ethyl acetate at a mass ratio of azobisisobutyronitrile:methacrylic acid:methyl methacrylate:butyl acrylate:ethyl acetate = (0.2-0.4):(6-8):(4-6):(16-20):100 to obtain a first mixed monomer; S430, while the first mixed monomer is in an ice-water bath, the first suspension is added dropwise to the first mixed monomer at a mass ratio of the first suspension: the first mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S440: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain a first shear thickener.

[0013] In the above technical solution, the preparation method of the second shear thickener includes: S510, mixing Tween 60 and silica nanoparticles in water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a second suspension; S520. In an ice-water bath, azobisisobutyronitrile, pentamethyldiethylenetriamine, polyethersulfone, methyl methacrylate, and butyl acrylate are mixed in dichloromethane at a mass ratio of azobisisobutyronitrile: pentamethyldiethylenetriamine: polyethersulfone: methyl methacrylate: butyl acrylate: dichloromethane = (0.2-0.4): (0.04-0.08): (4-6): (16-20): (4-8): 100 to obtain a second mixed monomer; S530, while the second mixed monomer is in an ice-water bath, the second suspension is added dropwise to the second mixed monomer at a mass ratio of the second suspension: the second mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S540: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain a second shear thickener.

[0014] In the above technical solution, S100 specifically includes: uniformly mixing the shear thickener and polyethylene glycol in water according to a mass ratio of shear thickener: polyethylene glycol: water = (2-4): (6-8): (20-22) to prepare an aqueous phase.

[0015] In the above technical solution, S200 specifically includes: mixing the smoothing agent, emulsifier, antistatic agent and agglomerating agent in a mass ratio of smoothing agent: emulsifier: antistatic agent: agglomerating agent = (38-44): (16-20): (4-6): (4-6) to obtain an oil phase.

[0016] In the above technical solution, S300 specifically includes: adding the oil phase heated to 65°C to 75°C dropwise into the water phase heated to 65°C to 75°C at a mass ratio of oil phase: water phase = (90-110):100, adjusting the pH value to neutral, and ultrasonically emulsifying the mixture to obtain a POY oil solution.

[0017] The present invention also provides a POY oil agent special for spinning, which is obtained by adopting the preparation method of any of the above technical solutions.

[0018] Beneficial effects The polyester POY oil agent of the present invention includes a shear thickener. Under the high shear conditions of POY spinning, the shear thickener can form a temporary "cluster structure" in the dispersion medium, hindering the flow of fluid, thereby increasing the viscosity of the POY oil agent. The shear thickener is a silica nanoparticle that has been modified with an acrylic copolymer. Under low temperature conditions, the acrylic copolymer can absorb shear energy through deformation and hinder the mutual friction of silica, thereby delaying the triggering of the thickening phenomenon. After the temperature exceeds 160°C, the acrylic copolymer accelerates dissolution and thermal decomposition, which increases the mutual friction, van der Waals force and hydrogen bonding of the silica nanoparticles, thereby causing the shear thickener to gradually trigger the shear thickening effect above 160°C, thereby regulating the viscosity of the POY oil agent under high temperature and high shear conditions, and balancing the sudden drop in viscosity of the POY oil agent caused by thermal decomposition of the oil phase and intensified molecular motion. Furthermore, the modified acrylic copolymer treatment reduces the surface energy of the silica nanoparticles, improving their dispersion stability. Even if the hydrophilic-lipophilic balance of the emulsifier shifts at low temperatures, the silica nanoparticles in the present invention remain relatively stable and are less likely to aggregate or settle. Therefore, the POY oil of the present invention can be stored stably at low temperatures and is less likely to delaminate or settle during long-term storage. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description of the specific embodiments of the present invention.

[0020] Unless otherwise specified, the reagents and raw materials used in the present invention can be purchased from commercial sources. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0021] POY oil is primarily used in the spinning process of POY polyester. It is an essential additive in the spinning process, ensuring that POY fibers possess excellent smoothness, bundling, and antistatic properties. Because POY polyester spins at high speeds and temperatures, POY oils must be able to maintain stable performance under high temperatures and shear forces.

[0022] The viscosity of the oil-in-water emulsion-based polyester POY lubricant commonly used in existing technologies decreases under high-temperature and high-shear process conditions. This decrease in viscosity makes it difficult for the lubricant to form a uniform film on the fiber surface, increasing friction between the fiber and the equipment, and causing lint or breakage.

[0023] In order to control the viscosity of the oil-in-water emulsion polyester POY oil to maintain stability under high temperature and high shear process conditions, the present invention adds a shear thickener to the POY oil. The preparation method of the POY oil for spinning provided by the present invention includes: S100, preparing an aqueous phase using raw materials including a shear thickener and polyethylene glycol; S200, preparing an oil phase using raw materials including a smoothing agent, an emulsifier, an antistatic agent, and a sizing agent; S300, adding the oil phase dropwise into the water phase and emulsifying uniformly to obtain a POY oil solution; The shear thickener is modified silica nanoparticles that have been modified with an acrylic copolymer. The acrylic copolymer modification process involves mixing silica nanoparticles with an organic substance comprising an acrylic acid monomer and / or an acrylate monomer, and then subjecting the mixture to a polymerization reaction under the action of an initiator to obtain the modified silica nanoparticles.

[0024] It is understood that the polyester POY oil agent of the present invention includes a shear thickener and polyethylene glycol. The polyethylene glycol serves as a dispersion medium for the shear thickener to improve the dispersion stability of the shear thickener. Preferably, a polyethylene glycol with a higher molecular weight can be used. Polyethylene glycol with a higher molecular weight has relatively good thermal stability due to its longer molecular chain. Its thermal decomposition temperature is usually higher than 300°C and can even reach about 400°C. The polyethylene glycol used in the embodiment of the present invention is PEG-20000. It is understood that High molecular weight polyethylene glycol still has good water solubility, but its dissolution rate is relatively slow. Therefore, a higher speed stirring condition and a longer stirring time can be used in the process of preparing the aqueous phase to ensure sufficient dissolution.

[0025] Shear thickening is a non-Newtonian fluid behavior that refers to the phenomenon in which the viscosity of a material increases when subjected to high shear stress or shear rate. Its mechanism is related to the interaction between particles in the dispersed system. Shear thickening particles are generally silica particles. At low shear rates, shear thickening particles are dispersed in polar or non-polar liquid media and flow freely, and the system exhibits low viscosity. When the shear rate exceeds a critical value, the friction or collision frequency between particles increases, causing the particles to form temporary "cluster structures", hindering the flow of the fluid, thereby increasing the viscosity. In addition, at high shear rates, the hydrodynamic forces between shear thickening particles dominate and cause the particles to be closely arranged. This phenomenon also increases the flow resistance.

[0026] In the textile industry, liquids or colloids containing shear-thickening particles are often used to impregnate textiles, creating protective gear such as kneepads, elbow pads, helmets, and body armor. Shear-thickening materials are also used in the automotive, aerospace, and construction industries to absorb energy during collisions and improve impact resistance and shock absorption.

[0027] The present invention is dedicated to using silica shear thickening particles in combination with other components such as a smoothing agent, an antistatic agent, a sizing agent, and an emulsifier to prepare a stable oil-in-water emulsion as a POY spinning oil. The invention aims to utilize the shear thickening phenomenon to regulate the viscosity of the POY oil under conditions of high temperature and high shear force, thereby avoiding significant viscosity changes of the POY oil during use.

[0028] When spinning polyester, the shear rate of the polyester melt passing through the spinneret is usually controlled at 1×10 4 s -1 to 3 × 10 4 s -1 , while polyester spinning temperatures exceed 200°C. The actual temperature of the POY finish during spinning is close to the melt temperature. Higher temperatures require greater shear thickening effect from the shear thickening particles. Therefore, controlling the shear thickening particles in the POY finish to function at higher temperatures is the first key issue addressed by this invention.

[0029] The applicant conducted research on how to control the viscosity of POY oil during the spinning process to maintain stability in its prior application, published with patent number CN117702312B. In this prior application, nanosilica was prepared in a porous form. In addition to its inherent shear-thickening properties, silica also serves as a carrier for cellulose-based viscosity modifiers, loading them with viscosity-modifying cellulose reagents (e.g., carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose). The viscosity regulation mechanism employed in this prior application is the controlled release of the viscosity modifier. When the viscosity modifier is released from the porous structure of the nanosilica, it increases the viscosity of the oil. This release of the viscosity modifier occurs when the ethyl cellulose coated on the surface of the porous nanosilica gradually dissolves due to increasing temperature and friction. Due to the solubility characteristics of ethyl cellulose, this prior application was able to maintain a stable viscosity of the POY oil at temperatures around 100°C. However, as mentioned above, the spinning temperature of POY oil can reach over 200°C, while the thermal stability of cellulose-based viscosity modifiers and coating layers is relatively low. Maintaining the viscosity stability of POY oil at high temperatures remains a difficult problem to solve with existing technologies.

[0030] To this end, the present invention adjusts the coating modification method for nano-silica particles. Compared with the existing technology of using ethyl cellulose to coat nano-silica, the present invention improves the coating layer components and preparation process.

[0031] The present invention uses acrylic acid monomers and / or acrylate monomers as raw materials. Under the action of an initiator, a polymerization reaction occurs to coat the surface of nano-silica particles with an acrylic copolymer film. This invention utilizes the characteristics of acrylic acid copolymers, which remain stable below 160°C and dissolve more rapidly and undergo thermal decomposition above 160°C, to coat and modify silica shear-thickening particles. Acrylic acid copolymers have excellent film-forming properties and can form a uniform, dense film on the surface of silica particles, limiting contact and friction between the silica particles. When the temperature exceeds 160°C, the coating on the silica shear-thickening particles gradually decomposes, causing the nano-silica to become more closely contacted and friction to increase. This shear-thickening effect gradually increases the viscosity of the aqueous phase in the POY oil, thereby balancing the viscosity drop caused by elevated temperature and high shear forces. The present invention can even maintain stable viscosity in POY oils at 200°C.

[0032] It should be noted that this invention focuses on the preparation process of a shear thickener capable of maintaining stable viscosity of POY oil at high temperatures. Those skilled in the art are capable of combining the shear thickener prepared by this invention with other prior art shear thickeners or viscosity-temperature-concentration modifiers (for example, combining this invention with the applicant's prior application CN117702312B) to produce a POY oil that maintains viscosity at temperatures around 100°C and at multiple temperatures above 100°C, as needed.

[0033] It should also be noted that when the silica dispersed phase is subjected to high shear forces in the continuous phase, the particles themselves form temporary "cluster structures" that hinder fluid flow, thereby achieving a shear thickening effect. In this case, if the silica is prepared in a porous form and a viscosity modifier is loaded into its pores, further and relatively more precise viscosity control can be achieved. However, given the very large specific surface area of porous silica, it is also more prone to reduced dispersion stability and low-temperature sedimentation. Therefore, to ensure uniform and stable dispersion of silica and better low-temperature storage stability of POY oil, the present invention does not adopt the technical concept of loading porous silica with a viscosity modifier. Instead, it studies the effect of the silica particles themselves on the viscosity of POY oil under high temperature and high shear conditions. Non-porous silica nanoparticles can be prepared by a vapor phase method. The silica used in this invention is commercially purchased non-porous silica nanoparticles with a D50 particle size of 60nm to 100nm.

[0034] In some embodiments of the present invention, S100 specifically includes: uniformly mixing the shear thickener and polyethylene glycol in water according to a mass ratio of shear thickener: polyethylene glycol: water = (2-4): (6-8): (20-22) to prepare an aqueous phase.

[0035] In some embodiments of the present invention, S200 specifically includes: mixing the smoothing agent, emulsifier, antistatic agent and aggregating agent in a mass ratio of smoothing agent: emulsifier: antistatic agent: aggregating agent = (38-44): (16-20): (4-6): (4-6) to obtain an oil phase.

[0036] In some embodiments of the present invention, S300 specifically includes: adding the oil phase heated to 65°C to 75°C dropwise into the water phase heated to 65°C to 75°C at a mass ratio of oil phase: water phase = (90-110):100, adjusting the pH value to neutral, and ultrasonically emulsifying the mixture to obtain a POY oil solution.

[0037] Those skilled in the art can select and adjust the specific types of components such as smoothing agents, emulsifiers, antistatic agents, and sizing agents based on actual needs. For example, smoothing agents can be selected from one or more of fatty alcohol polyoxyethylene polyoxypropylene random copolymer polyethers, ethylene oxide and propylene oxide random copolymer polyethers, dialkyl-terminated polyethers, and white oils. Emulsifiers can be selected from one or more of saturated fatty alcohol polyoxyethylene ethers, polyoxyethylene cholesterol ethers, fatty acid polyethylene glycol esters, lauryl alcohol polyoxyethylene ethers, polyoxyethylene sorbitan monostearate, sodium oleate, and potassium oleate. Antistatic agents can be selected from one or more of alkyl phosphate potassium salts, alkyl sulfonate salts, alkyl sulfate salts, dodecyl dimethylamine oxide, alkyl quaternary ammonium salts, and fatty alcohol polyoxyethylene ether phosphate salts. Sizing agents can be selected from one or more of fatty acid triethanolamine salts, oleic acid triethanolamine salts, lauryl polyoxyethylene ether, polyoxyethylene polyoxypropylene ether, sulfated castor oil, castor oil polyoxyethylene ether, and coconut oil fatty acid diethanolamide.

[0038] In an embodiment of the present invention, the smoothing agent specifically comprises lauric acid random polyether LPE-1200 and trimethylolpropane oleate, wherein the mass ratio of lauric acid random polyether LPE-1200 to trimethylolpropane oleate is (3-4):1. The emulsifier specifically comprises fatty alcohol polyoxyethylene ether. The antistatic agent specifically comprises lauryl alcohol potassium phosphate polyoxyethylene ether. The sizing agent specifically comprises polyethylene glycol dioleate.

[0039] After solving the technical problem of how to control the shear thickening particles in POY oil to function under higher temperature conditions, the second key problem to be solved by the present invention is how to broaden the operating temperature range in which the shear thickening particles can exert their thickening effect.

[0040] In some embodiments of the present invention, the shear thickener includes a first shear thickener and a second shear thickener, wherein the first shear thickener is a first modified silica nanoparticle modified with a first acrylic copolymer, and the second shear thickener is a second modified silica nanoparticle modified with a second acrylic copolymer; wherein, when the first acrylic copolymer and the second acrylic copolymer are prepared separately, the raw material components and / or raw material ratios used are different.

[0041] Acrylic copolymers having different raw material components and / or raw material ratios have different physical and chemical properties. For example, the weight-average molecular weight of the first acrylic copolymer is lower than the weight-average molecular weight of the second acrylic copolymer; and / or the thermal decomposition temperature of the first acrylic copolymer is lower than the thermal decomposition temperature of the second acrylic copolymer.

[0042] By modifying silica nanoparticles with acrylic copolymers exhibiting different physical and chemical properties (especially different thermal decomposition temperatures), it is possible to obtain silica nanoparticles that exhibit shear thickening properties under different temperature conditions. Mixing these two types of silica nanoparticles broadens the operating temperature range within which the shear thickening particles exert their thickening effect. Preferably, the mass ratio of the first shear thickener to the second shear thickener is (150-200):100.

[0043] In some embodiments of the present invention, the preparation method of the first shear thickener includes: S410, mixing Tween 60 and silica nanoparticles in water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a first suspension; S420. In an ice-water bath, azobisisobutyronitrile, methacrylic acid, methyl methacrylate, and butyl acrylate are mixed in ethyl acetate at a mass ratio of azobisisobutyronitrile:methacrylic acid:methyl methacrylate:butyl acrylate:ethyl acetate = (0.2-0.4):(6-8):(4-6):(16-20):100 to obtain a first mixed monomer; S430, while the first mixed monomer is in an ice-water bath, the first suspension is added dropwise to the first mixed monomer at a mass ratio of the first suspension: the first mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S440: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain a first shear thickener.

[0044] In some embodiments of the present invention, the preparation method of the second shear thickener includes: S510, mixing Tween 60 and silica nanoparticles in water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a second suspension; S520. In an ice-water bath, azobisisobutyronitrile, pentamethyldiethylenetriamine, polyethersulfone, methyl methacrylate, and butyl acrylate are mixed in dichloromethane at a mass ratio of azobisisobutyronitrile: pentamethyldiethylenetriamine: polyethersulfone: methyl methacrylate: butyl acrylate: dichloromethane = (0.2-0.4): (0.04-0.08): (4-6): (16-20): (4-8): 100 to obtain a second mixed monomer; S530, while the second mixed monomer is in an ice-water bath, the second suspension is added dropwise to the second mixed monomer at a mass ratio of the second suspension: the second mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S540: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain a second shear thickener.

[0045] Tween 60 is a polyoxyethylene sorbitan fatty acid ester. As a nonionic emulsifier, it is highly water-soluble and therefore added to the aqueous phase. The silica nanoparticles used in S410 and S510 of the present invention are preferably non-porous silica nanoparticles with a D50 particle size of 60 to 100 nm. The ice-water bath conditions used in S420 and S520 of the present invention are between 0° and 5°. Azobisisobutyronitrile is used as an initiator in S420 and S520 of the present invention. Ethyl acetate and dichloromethane are used as reaction media in S420 and S520 of the present invention. Other acrylic acid or acrylic acid ester raw materials used in S420 and S520 of the present invention are monomer raw materials. Pentamethyldiethylenetriamine (PMDETA) is used as a chelating agent in S520 of the present invention. Polyethersulfone is used in S520 of the present invention to increase the thermal decomposition temperature of the acrylic acid copolymer.

[0046] When preparing the first mixed monomer of the present invention, the proportion of butyl acrylate is higher and the proportion of methyl methacrylate is lower. When preparing the second mixed monomer of the present invention, the proportion of butyl acrylate is lower, the proportion of methyl methacrylate is higher, and polyethersulfone is added. The ester side chain of methyl methacrylate is methyl, the molecular chain is relatively rigid, the glass transition temperature is relatively high, and its thermal decomposition temperature is also relatively high. The ester side chain of butyl acrylate is a long-chain butyl, the molecular chain is flexible, the glass transition temperature is relatively low, and its thermal decomposition temperature is relatively low. In addition, by using polyethersulfone in combination, the present invention can coat the surface of silica nanoparticles with two acrylic copolymers with different thermal decomposition temperatures, and then by regulating the addition ratio of the first shear thickener and the second shear thickener, the POY oil agent can maintain stable viscosity over a wider temperature range.

[0047] Example 1 In this example, a series of shear thickener samples 1 to 4 were prepared. The raw material ratios thereof are shown in Table 1, and the preparation process thereof is as follows.

[0048] S1. Mix Tween 60 and water in a beaker according to the mass ratio in Table 1, add silica nanoparticles, and disperse them ultrasonically at a power of 200 W for 10 minutes to obtain a first suspension; S2. According to the mass ratio in Table 1, ethyl acetate was first placed in a beaker, and the temperature was cooled to below 4° C. in an ice-water bath. Methacrylic acid, methyl methacrylate, and butyl acrylate were then added to the beaker, and the mixture was stirred evenly. Azobisisobutyronitrile was then added, and the mixture was stirred evenly again to obtain a first mixed monomer. S3. While the first mixed monomer is in an ice-water bath and the temperature is below 4° C., the first suspension is added dropwise into the beaker containing the first mixed monomer using a dropper according to the mass ratio in Table 1 and magnetically stirred simultaneously. Each time the first suspension is removed, the first suspension is gently stirred using a dropper to ensure uniform removal. After the addition is complete, the mixture in the beaker is ultrasonically emulsified at a power of 600 W for more than 30 minutes to ensure uniform emulsification. The mixture in the beaker is then transferred to a three-necked flask. After replacing the air with nitrogen, the three-necked flask is heated to 65° C. and kept warm for 35 minutes. S4. After the reaction is completed, the three-necked flask is cooled to room temperature and allowed to stand for about 2 hours. The precipitate is separated by centrifugation, and the precipitate is washed and dried to obtain shear thickener samples 1 to 4.

[0049] Table 1 Example 2 In this example, a series of shear thickener samples 5 to 6 were prepared. The raw material ratios thereof are shown in Table 2, and the preparation process thereof is as follows.

[0050] S1. According to the mass ratio in Table 2, Tween 60 and water were mixed in a beaker, and then silica nanoparticles were added. The mixture was ultrasonically dispersed at a power of 200 W for 10 min to obtain a second suspension. S2. According to the mass ratio in Table 2, dichloromethane was first placed in a beaker, and the temperature was lowered to below 4°C in an ice-water bath. Pentamethyldiethylenetriamine, polyethersulfone, methyl methacrylate, and butyl acrylate were then added to the beaker, and the mixture was stirred evenly. Azobisisobutyronitrile was then added, and the mixture was stirred evenly again to obtain a second mixed monomer. S3. While the second mixed monomer is in an ice-water bath and the temperature is below 4° C., the second suspension is added dropwise into the beaker containing the second mixed monomer using a dropper according to the mass ratio in Table 2 and magnetically stirred simultaneously. Each time the second suspension is removed, the second suspension is gently stirred using a dropper to ensure uniform removal. After the addition is completed, the mixture in the beaker is ultrasonically emulsified at a power of 500 W for more than 30 minutes to ensure uniform emulsification. The mixture in the beaker is then transferred to a three-necked flask. After replacing the air with nitrogen, the three-necked flask is heated to 65° C. and kept warm for 1 hour. S4. After the reaction is completed, the three-necked flask is cooled to room temperature and allowed to stand for about 2 hours. The precipitate is separated by centrifugation, and the precipitate is washed and dried to obtain shear thickener samples 5 to 6.

[0051] Table 2 Example 3 In this example, a series of POY oil samples 1 to 8 were prepared. The raw material ratios were shown in Table 3, and the preparation process was as follows.

[0052] S1. Mix the shear thickener and polyethylene glycol in a beaker according to the mass ratio in Table 3, then add water and ultrasonically disperse at a power of 400 W for 20 minutes to obtain an aqueous phase; S2. According to the mass ratio in Table 3, lauric acid random polyether LPE-1200, trimethylolpropane oleate, fatty alcohol polyoxyethylene ether, lauryl alcohol potassium phosphate polyoxyethylene ether and polyethylene glycol dioleate were mixed and stirred in a beaker to obtain an oil phase; S3. Heat the oil phase and water phase to 70°C respectively at a mass ratio of 1:1, then add the oil phase dropwise into the water phase while stirring. After the addition is complete, adjust the pH value to neutral and emulsify uniformly using ultrasonic emulsification at a power of 600 W to obtain a POY oil solution.

[0053] Table 3 Performance Testing POY oil samples 1 to 8 were heated at a rate of 18°C / min to 20°C / min and stirred at 1500 rpm to simulate shear friction during use. The viscosity of POY oil samples 1 to 8 was measured during the heating and stirring process. The test results are shown in Table 4. Table 4 shows that the initial viscosity of POY oil samples 1 to 8, sampled at 40°C, was approximately 80 cP. As the temperature increased, the viscosity gradually changed. In the temperature range of 140°C to 160°C, the viscosity of POY oil samples 1 to 8 decreased significantly. Around 170°C, the viscosity of the POY oil rebounded and remained relatively stable in the temperature range of 170°C to 180°C. In the temperature range of 190°C to 200°C, the viscosity of the POY oil rebounded again. For POY oil samples 1 to 8, the average viscosity change between the initial viscosity at 40°C and the high-temperature viscosity at 200°C was 1.2 cP. Among them, Samples 1, 6, and 7 showed the smallest viscosity changes. Sample 6 had the lowest rate of viscosity change. Furthermore, POY finish samples 1 through 8 were refrigerated and stored at 5°C for 15 days. Observation of their appearance revealed no delamination or precipitation. After refrigerated storage, spinning using POY finish samples 1 through 8 revealed no noticeable linting or end breakage in the POY fibers.

[0054] Table 4 Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for preparing a POY oil for spinning, characterized in that: The preparation method comprises: S100, preparing an aqueous phase using raw materials including a shear thickener and polyethylene glycol; S200, preparing an oil phase using raw materials including a smoothing agent, an emulsifier, an antistatic agent, and a sizing agent; S300, adding the oil phase dropwise into the water phase and emulsifying uniformly to obtain the POY oil solution; Wherein, the shear thickener is modified silicon dioxide nanoparticles modified by acrylic acid copolymer.

2. The preparation method according to claim 1, characterized in that The acrylic copolymer modification treatment is carried out by mixing the silicon dioxide nanoparticles with an organic substance including an acrylic acid monomer and / or an acrylate monomer, and obtaining the modified silicon dioxide nanoparticles through a polymerization reaction under the action of an initiator.

3. The preparation method according to claim 1, characterized in that The shear thickener includes a first shear thickener and a second shear thickener, wherein the first shear thickener is first modified silica nanoparticles modified with a first acrylic copolymer, and the second shear thickener is second modified silica nanoparticles modified with a second acrylic copolymer; wherein, when the first acrylic copolymer and the second acrylic copolymer are prepared separately, different raw material components and / or raw material ratios are used for the two.

4. The preparation method according to claim 3, characterized in that The weight average molecular weight of the first acrylic copolymer is less than the weight average molecular weight of the second acrylic copolymer; and / or The thermal decomposition temperature of the first acrylic copolymer is lower than the thermal decomposition temperature of the second acrylic copolymer; and / or In the shear thickener, the mass ratio of the first shear thickener to the second shear thickener is (150-200):

100.

5. The preparation method according to claim 3, characterized in that The preparation method of the first shear thickener comprises: S410, mixing the Tween 60 and the silica nanoparticles in the water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a first suspension; S420. In an ice-water bath, the azobisisobutyronitrile, the methacrylic acid, the methyl methacrylate, and the butyl acrylate are mixed in the ethyl acetate at a mass ratio of azobisisobutyronitrile:methacrylic acid:methyl methacrylate:butyl acrylate:ethyl acetate = (0.2-0.4):(6-8):(4-6):(16-20):100 to obtain a first mixed monomer; S430, while the first mixed monomer is in an ice-water bath, the first suspension is added dropwise to the first mixed monomer at a mass ratio of first suspension:first mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S440: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain the first shear thickener.

6. The preparation method according to claim 3, characterized in that The preparation method of the second shear thickener comprises: S510, mixing the Tween 60 and the silica nanoparticles in the water at a mass ratio of Tween 60: silica nanoparticles: water = (2-4): (15-25): 100 to obtain a second suspension; S520. In an ice-water bath, the azobisisobutyronitrile, pentamethyldiethylenetriamine, polyethersulfone, methyl methacrylate, and butyl acrylate are mixed in dichloromethane at a mass ratio of azobisisobutyronitrile: pentamethyldiethylenetriamine: polyethersulfone: methyl methacrylate: butyl acrylate: dichloromethane = (0.2-0.4): (0.04-0.08): (4-6): (16-20): (4-8): 100 to obtain a second mixed monomer; S530, while the second mixed monomer is in an ice-water bath, the second suspension is added dropwise to the second mixed monomer at a mass ratio of second suspension: second mixed monomer = (40-60):100, while stirring simultaneously. After the dropwise addition is complete, ultrasonic emulsification is performed, and the mixture is heated to a temperature of 62° C. to 68° C. under a protective atmosphere, and the reaction is kept warm for 20 minutes to 1 hour; S540: After the reaction is completed, the mixture is cooled to room temperature and allowed to stand, and the precipitate is separated, washed, and dried to obtain the second shear thickener.

7. The preparation method according to any one of claims 1 to 6, characterized in that S100 specifically includes: uniformly mixing the shear thickener and the polyethylene glycol in the water according to a mass ratio of shear thickener: polyethylene glycol: water = (2-4): (6-8): (20-22) to prepare the aqueous phase.

8. The preparation method according to any one of claims 1 to 6, characterized in that S200 specifically includes: uniformly mixing the smoothing agent, the emulsifier, the antistatic agent and the aggregating agent according to a mass ratio of smoothing agent: emulsifier: antistatic agent: aggregating agent = (38-44): (16-20): (4-6): (4-6) to prepare the oil phase.

9. The preparation method according to any one of claims 1 to 6, characterized in that S300 specifically includes: adding the oil phase heated to 65° C. to 75° C. dropwise into the water phase heated to 65° C. to 75° C. at a mass ratio of oil phase to water phase = (90-110):100, adjusting the pH value to neutral, and performing ultrasonic emulsification to obtain the POY oil solution.

10. A POY oil agent for spinning, characterized in that: The POY oil is obtained by the preparation method according to any one of claims 1 to 9.

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