A sizing composition applied to polyamide ultrafine denier yarns and a method for preparing the same

Abstract

The application relates to the technical field of textile sizing, and discloses a sizing composition applied to nylon ultrafine denier yarn and a preparation method thereof.The sizing composition applied to the nylon ultrafine denier yarn comprises soft monomers, hard monomers and functional monomers, the soft monomers comprise ester group-containing acrylic compounds, and the functional monomers comprise carbonyl group-containing acrylic compounds.The ester group-containing acrylic compounds and the carbonyl group-containing acrylic compounds are adopted to build a microstructure of "harmony of rigidity and flexibility" in the sizing, to improve the intermolecular and intramolecular interaction force, to form a sizing film with strong toughness, low tack, strong adhesion and good permeability, to prevent weaving interruption, to reduce the hygroscopicity of the sizing film, and to improve the permeability of the sizing film to fiber bundles.

Description

Technical Field

[0001] This application relates to the field of textile sizing technology, specifically to a sizing composition for use in nylon ultrafine denier filaments and its preparation method. Background Technology

[0002] Nylon microfiber, with its extremely low fineness, endows fabrics with a silky softness, gentle luster, and excellent drape, thus occupying a pivotal position in the high-end textile industry. However, this type of fiber faces stringent challenges in the weaving preparation process—especially the sizing process. First, the fiber's extremely high specific surface area places more stringent requirements on the adsorption performance and film-forming quality of the sizing film. Second, its relatively low monofilament strength makes it highly susceptible to damage under the high tension and friction conditions during processing. Third, the inherent hygroscopic properties of nylon materials easily lead to the sizing film becoming damp and sticky. These inherent characteristics collectively constitute the technical barriers to the sizing process of nylon microfiber.

[0003] Currently, there is a lack of specialized sizing agents for the characteristics of ultra-fine denier nylon in the market. The industry generally uses a simple formulation based on conventional spinning oils or general textile sizing agents (such as acrylates, PVA, starch, etc.). However, this stopgap measure cannot meet the stringent sizing requirements of ultra-fine denier nylon. Its limitations are mainly reflected in the following three aspects: First, toughness defects: the sizing film formed by existing compounded sizing agents is often hard and brittle, lacking sufficient flexibility and fatigue resistance; Second, under the high-frequency alternating stress of the weaving process... First, the sizing film is prone to brittleness and shedding, leading to fuzz regeneration and directly reducing weaving efficiency and yield. Second, it suffers from moisture absorption and re-adhesion. Due to insufficient adaptation to the moisture absorption characteristics of nylon, the sizing film easily absorbs moisture and becomes sticky again in the high-temperature and high-humidity environment of the weaving workshop, causing adjacent yarns to stick together and unclear openings, which seriously affects the smoothness of the fabric surface and the quality of the fabric. Third, it has poor permeability. Due to the lack of interfacial compatibility and molecular structure design, the sizing agent cannot effectively penetrate into the interior of the ultra-fine denier fiber bundles, resulting in insufficient cohesion between fibers and poor yarn bundle cohesion. Therefore, the existing technical solutions, due to the lack of systematic molecular design and performance regulation, cannot fundamentally solve the problems of "high toughness" and "low re-adhesion" in sizing of ultra-fine denier nylon. Summary of the Invention

[0004] This application provides a sizing composition for use in nylon microfiber yarn and a method for preparing the same, in order to solve the above-mentioned problems.

[0005] In a first aspect, this application provides a sizing composition for use in nylon microfiber yarn, comprising: a chain transfer agent, a soft monomer, a hard monomer, and a functional monomer, wherein the soft monomer comprises an acrylic compound containing an ester group, and the functional monomer comprises an acrylic compound containing a carbonyl group.

[0006] In one optional embodiment, the soft monomer includes at least one of ethyl acrylate (EA), butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA, EHA), and isooctyl acrylate (IOA), preferably butyl acrylate and 2-ethylhexyl acrylate.

[0007] In one optional embodiment, the functional monomer includes at least one of acrylic acid (AA), methacrylic acid (MAA), hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), acrylamide (AM), N-hydroxymethylacrylamide (NMA), glycidyl methacrylate (GMA), allyl methacrylate (ALMA), and trimethylolpropane triacrylate (TMPTA), preferably methacrylic acid and N-hydroxymethylacrylamide.

[0008] In one alternative embodiment, the hard monomer includes at least one of methyl acrylate (MA), methyl methacrylate (MMA), styrene (St), and acrylonitrile (AN).

[0009] In one alternative embodiment, the slurry composition further includes water, chain transfer agent, emulsifier, initiator, toughening agent, and additives.

[0010] In one alternative embodiment, the chain transfer agent includes at least one of n-dodecyl mercaptan, tert-dodecyl mercaptan, mercaptoethanol, mercaptoacetic acid, and isopropanol, and the chain transfer agent is used to adjust the molecular weight of the polymer.

[0011] In one optional embodiment, the emulsifier comprises anionic and nonionic emulsifiers, wherein the anionic emulsifier comprises at least one of sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), sodium fatty alcohol polyoxyethylene ether sulfate (AES), alkyl diphenyl ether disulfonate, sodium alkenyl sulfonate (AOS), and sodium succinate sulfonate; and the nonionic emulsifier comprises at least one of Pingpingjia O-25, alkylphenol polyoxyethylene ether OP-10, Span 60, polysorbate-20, and nonylphenol polyoxyethylene ether NP-9.

[0012] In one optional embodiment, the toughening agent includes at least one of carboxymethyl starch (CMS), polyacrylamide (PAM), and waterborne polyurethane (WPU), preferably waterborne polyurethane.

[0013] In one alternative embodiment, the initiator includes at least one of a water-soluble thermal decomposition initiator system or a redox initiator system.

[0014] In one optional embodiment, the initiator of the water-soluble thermal decomposition initiator system includes a persulfate, wherein the persulfate includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0015] In one optional embodiment, the oxidant in the redox initiator system includes at least one of persulfate and tert-butyl hydroperoxide, wherein the persulfate includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0016] In one optional embodiment, the reducing agent in the redox initiator system includes at least one of sodium bisulfite, sodium metabisulfite, sodium formaldehyde sulfoxylate, triethanolamine, vitamin C, and ascorbic acid.

[0017] In one alternative embodiment, the additive includes at least one of a neutralizer, a defoamer, a wetting and penetrating agent, and an antistatic agent.

[0018] In one alternative embodiment, the neutralizing agent includes at least one of ammonia or sodium hydroxide.

[0019] In one alternative embodiment, the defoamer includes at least one of mineral oils (SGR1840, RHODOLINE DF691, etc.), silicones (Momentive SAG 638, SAG ENDURE, TEGO Antifoam X206, etc.), or polyether organics (PPG620 10PO, DC-5200).

[0020] In one alternative embodiment, the wetting and penetrating agent includes at least one of sodium dioctyl sulfosuccinate (OT-75) and fatty alcohol polyoxyethylene ether (JFC).

[0021] In one optional embodiment, the antistatic agent includes at least one of nonionic surfactants and anionic surfactants.

[0022] In one alternative embodiment, the nonionic surfactant comprises glyceryl monostearate, and the anionic surfactant comprises at least one of DENON 3342 or DPE.

[0023] In one alternative embodiment, the neutralizing agent is selected from at least one of ammonia water and sodium hydroxide solution, and is used to adjust the pH value of the slurry.

[0024] In one optional embodiment, the soft monomer has a mass fraction of 5-20 parts, the hard monomer has a mass fraction of 5-20 parts, and the functional monomer has a mass fraction of 2-10 parts.

[0025] In one optional embodiment, the chain transfer agent is present in a mass fraction of 0.01-0.1 parts.

[0026] In one alternative embodiment, the water comprises 50-65 parts by mass.

[0027] In one alternative embodiment, the emulsifier is present in parts by weight of 1-6 parts.

[0028] Secondly, this application also provides a method for preparing a sizing composition for use in nylon microfiber filaments, comprising the following steps: in the presence of functional additives, mixing a chain transfer agent, a soft monomer, a hard monomer and a functional monomer to initiate a reaction, thereby forming a sizing composition for use in nylon microfiber filaments.

[0029] In one alternative embodiment, the initiation reaction includes at least one of a redox initiation reaction and a thermal decomposition initiation reaction.

[0030] In one optional embodiment, the specific steps of the redox initiation reaction include initiating a reaction between a chain transfer agent, a soft monomer, a hard monomer, and a functional monomer in the presence of an emulsifier solution, using an oxidant and a reducing agent as initiators, at a reaction temperature of 60-65°C. The oxidant includes at least one of persulfate and tert-butyl hydroperoxide, and the reducing agent includes at least one of sodium bisulfite, sodium metabisulfite, sodium formaldehyde sulfoxylate, triethanolamine, and ascorbic acid.

[0031] In one alternative embodiment, the persulfate includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0032] In one optional embodiment, the specific steps of the thermal decomposition initiation reaction include, in the presence of an emulsifier solution, using a water-soluble thermal decomposition initiator as an initiator, initiating the reaction of the chain transfer agent, soft monomer, hard monomer, and functional monomer at a temperature of 82-86°C, wherein the water-soluble thermal decomposition initiator includes persulfate.

[0033] In one optional embodiment, the thermal decomposition initiation reaction involves first adding a first part by weight of a water-soluble thermal decomposition initiator for a primary reaction, then adding a soft monomer, a hard monomer, a functional monomer, and a second part by weight of a water-soluble thermal decomposition initiator for a secondary reaction. The mass ratio of the first part by weight of the water-soluble thermal decomposition initiator to the second part by weight of the water-soluble thermal decomposition initiator is 1-3:7-9. The reaction time for the primary reaction is 2-4 min, and the reaction time for the secondary reaction is 60-210 min. Preferably, the reaction time for the secondary reaction is 180-210 min.

[0034] In one optional embodiment, the chain transfer agent is 0.01-1 parts by mass, the soft monomer is 5-20 parts by mass, the hard monomer is 5-20 parts by mass, the functional monomer is 2-10 parts by mass, and the emulsifier is 1-6 parts by mass.

[0035] In one optional embodiment, in the redox initiation reaction, the amount of oxidant is 0.1-0.4 wt% and the amount of reductant is 0.1-0.5 wt% based on the total weight of the soft monomer, hard monomer, and functional monomer; In one optional embodiment, in the thermal decomposition initiation reaction, the mass of the water-soluble thermal decomposition initiator is 0.2-0.8% based on the total weight of the soft monomer, hard monomer, and functional monomer; In one alternative embodiment, the functional additive includes an emulsifier and an initiator.

[0036] In one alternative implementation, after initiating the reaction, the steps further include ripening, adding additives, and adjusting the sugar content of the slurry.

[0037] In one alternative implementation, the curing time is 60-100 min.

[0038] In one optional embodiment, after aging, the temperature of the reaction solution is lowered, and additives are added to it. The additives include a neutralizer, an antifoaming agent, a wetting and penetrating agent, a toughening agent, and an antistatic agent. The temperature of the reaction solution is lowered to 40-50°C. Based on the mass of the reaction solution, the mass of the antifoaming agent is 0.1-0.5 wt%, the mass of the wetting and penetrating agent is 0.5-2 wt%, the mass of the toughening agent is 1-5 wt%, the mass of the antistatic agent is 0.5-3 wt%, and the neutralizer adjusts the pH value of the reaction solution to 7-8.

[0039] In one alternative embodiment, the sugar content of the slurry is 20-25.

[0040] In one alternative embodiment, the concentration of the water-soluble thermal decomposition initiator is 3-10 wt%.

[0041] In one alternative embodiment, the concentration of the oxidant is 4-10 wt%.

[0042] In one alternative embodiment, the concentration of the reducing agent is 1-6 wt%.

[0043] The technical solution of this application has the following advantages: 1. This application provides a sizing composition for use in nylon microfiber yarn, comprising: a soft monomer, a hard monomer, and a functional monomer. The soft monomer contains an acrylic compound with ester groups, and the functional monomer contains an acrylic compound with carbonyl groups. This application utilizes acrylic compounds containing ester groups and acrylic compounds containing carbonyl groups. The soft monomer provided in this application has a carbon-carbon single bond main chain, with ester groups in the side chains. The side chains are relatively long or branched, have a low glass transition temperature (Tg), and strong molecular chain mobility, providing flexibility and deformability to the sizing film. The carbonyl groups of the functional monomer provide rigidity, and the dense hydrogen bond network provides strength and adhesion. This application uses copolymerization and microphase separation to form a flexible continuous phase encapsulating rigid physical crosslinking points in a microstructure, constructing a "rigid-flexible" microstructure. This enhances intermolecular and intramolecular interactions, resulting in a sizing film with high toughness, low back tack, strong adhesion, and good permeability. This prevents weaving breakage, reduces hygroscopicity, and improves the film's permeability to fiber bundles.

[0044] 2. This application provides a sizing composition for use in nylon microfiber yarn, wherein the soft monomer includes at least one of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate, preferably butyl acrylate and 2-ethylhexyl acrylate; the functional monomer includes at least one of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylamide, N-hydroxymethylacrylamide, glycidyl methacrylate, allyl methacrylate, and trimethylolpropane triacrylate (TMPTA), preferably methacrylic acid and N-hydroxymethylacrylamide. This application uses butyl acrylate and 2-ethylhexyl acrylate as soft monomers. The side chain of butyl acrylate is a straight-chain butyl ester group, which has good molecular chain regularity and a glass transition temperature of -54℃, giving the film flexibility. The side chain of 2-ethylhexyl acrylate is a 2-ethylhexyl ester group, which enhances the mobility of the molecular chain. By using butyl acrylate and 2-ethylhexyl acrylate together, a structure of compliant main chain and hydrophobic side chain is formed, which can not only improve the flexibility of the film, but also reduce the hygroscopic and tacky characteristics. Furthermore, methacrylic acid and N-hydroxymethylacrylamide are used as functional monomers. Under the support of the soft and variable skeleton structure formed by butyl acrylate and 2-ethylhexyl acrylate, methacrylic acid is more conducive to exposing its carboxyl groups, while N-hydroxymethylacrylamide is grafted onto the skeleton, which not only limits the excessive hygroscopic migration of the molecular chain, but also prevents the film from becoming hard and brittle. The final film has the characteristics of high toughness and low tackiness.

[0045] 3. This application provides a sizing composition for use in nylon microfiber yarns, the sizing composition further comprising a chain transfer agent, an emulsifier, an initiator, a toughening agent, and auxiliaries. The introduction of chain transfer agents, emulsifiers, initiators, toughening agents, and auxiliaries in this application ensures that the nylon microfiber yarn sizing composition maintains clear opening even in high-temperature and high-humidity weaving workshop environments.

[0046] 4. This application provides a sizing composition for use in nylon microfiber yarns, wherein the toughening agent includes at least one of carboxymethyl starch, polyacrylamide, and waterborne polyurethane, preferably waterborne polyurethane. This application uses carboxymethyl starch, polyacrylamide, and waterborne polyurethane as toughening agents. The soft segments of the waterborne polyurethane have better compatibility with the soft monomers butyl acrylate and 2-ethylhexyl acrylate to form a flexible and variable skeleton structure, forming physical crosslinking points in the sizing film, further improving the toughness, tensile strength, and impact resistance of the sizing film.

[0047] 5. This application provides a sizing composition for use in nylon microfiber filaments, wherein the emulsifier includes both anionic and nonionic emulsifiers. This application selects both anionic and nonionic emulsifiers as emulsifiers, and through the synergistic effect of electrostatic repulsion and steric hindrance, forms an emulsion with uniform particle size and excellent stability. This not only ensures the stability of the polymerization process and the storage stability of the sizing, but also helps to form a continuous and dense sizing film on the surface of the nylon microfiber filaments.

[0048] 6. This application provides a method for preparing a sizing composition for use in nylon microfiber filaments, comprising the following steps: in the presence of an initiator, mixing soft monomers, hard monomers, and functional monomers to initiate a reaction, thereby forming a sizing composition for use in nylon microfiber filaments. The preparation method provided in this application is simple in procedure, and the resulting sizing film is suitable for high-temperature and high-humidity weaving environments.

[0049] 7. This application provides a method for preparing a sizing composition for use in nylon ultrafine denier filaments, wherein the initiation reaction includes at least one of redox initiation and thermal decomposition initiation. This application provides two polymerization processes, thermal initiation and redox initiation, which can be flexibly selected according to production conditions and adapted to production processes at different temperatures. Detailed Implementation

[0050] The following embodiments are provided to better understand this application. However, the following embodiments do not constitute a limitation on the content and scope of protection of this application. Any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining the features of this application with other prior art, falls within the scope of protection of this application.

[0051] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0052] One part of each embodiment and comparative example in this application specification is equal to 2g.

[0053] Example 1 This embodiment provides a method for preparing a sizing composition for use in nylon microfiber yarns. The specific steps and methods are as follows: (1) In a reaction flask equipped with a stirrer, condenser, thermometer and dropping device, add 55 parts of deionized water, 0.8 parts of SDBS and 1.2 parts of OP-10, and stir evenly at 300 rpm. (2) In a monomer tank, add 0.05 parts of n-dodecyl mercaptan, 13 parts of BA, 2 parts of EHA, 13 parts of MMA, 3 parts of St, 0.5 parts of HPA, 2.5 parts of MAA and 0.5 parts of NMA in sequence, stir evenly and set aside to form a mixed monomer; (3) Dissolve 0.07 parts of APS in 1.2 parts of deionized water to prepare an oxidizing agent with an APS aqueous solution of about 5.8% by mass; Dissolve 0.08 parts of sodium bisulfite in 3 parts of deionized water to prepare a freshly prepared reducing agent with a mass fraction of approximately 2.56%, and place it in a light-proof dropping container; (4) After heating the reaction flask of step (1) to 62°C, add the mixed monomer, oxidant and reducing agent dropwise simultaneously. The dropwise addition time is 210 minutes. During the dropwise addition, keep the temperature at 62±2°C. (5) After all materials have been added, continue stirring at 300 rpm for 60 minutes at 62°C to allow the remaining monomers to continue to react completely. (6) Cool down to 45°C, adjust the pH of the emulsion to 7.5 with ammonia water, and then add 0.3 parts of defoamer SAG638, 1.2 parts of wetting and penetrating agent OT-75, 1 part of antistatic agent glyceryl monostearate and 5 parts of waterborne polyurethane WPU. After the addition is complete, continue to stir for 30 minutes to make it evenly mixed to form an emulsion. (7) Add about 2 parts of deionized water to the emulsion to adjust the sugar content of the slurry to 23, filter it in a 250 mesh nylon filter bag, and the slurry composition can be obtained.

[0054] Example 2 This embodiment provides a method for preparing a sizing composition for use in nylon microfiber yarns. The specific steps and methods are as follows: (1) In a reaction flask equipped with a stirrer, condenser, thermometer and dropping device, add 55 parts water, 1.0 part AES and 1.5 parts Pingping O-25, and stir evenly at 300 rpm. (2) In the monomer tank, add 0.03 parts mercaptoethanol, 10 parts BA, 5 parts IOA, 12 parts MMA, 4 parts St, 1.0 part MAA, 1.5 parts HEMA and 1 part GMA in sequence, stir well and set aside. (3) Prepare a thermal decomposition initiator solution by dissolving 0.3 parts of APS in 5 parts of deionized water to prepare an APS aqueous solution with a mass fraction of 6% as the initiator; (4) After heating the reaction flask in step (1) to 84°C, add 20wt% initiator solution as the initial initiator. After stirring for 3 minutes, add the mixed monomer and the remaining initiator dropwise over a period of 210 minutes. (5) After the addition is complete, continue stirring at 300 rpm at 84℃ and keep warm for 60 minutes to mature; (6) Cool to 40℃, add ammonia to adjust the pH of the emulsion to 7.5, then add 0.25 parts of defoamer DF691, 2.0 parts of wetting and penetrating agent JFC, 1.5 parts of antistatic agent DENON 3342 and 3.0 parts of thickener CMS. After the addition is complete, continue stirring for 30 minutes to mix evenly; (7) Add about 3 parts of deionized water to the emulsion to adjust the sugar content of the slurry to 23, filter it in a 250 mesh nylon filter bag, and you can obtain the high toughness and low back adhesion nylon ultrafine denier slurry composition.

[0055] Example 3 This embodiment provides a method for preparing a sizing composition for use in nylon microfiber yarns. The specific steps and methods are as follows: (1) In a reaction flask equipped with a stirrer, condenser, thermometer and dropping device, add 58 parts water, 1.2 parts AOS and 1.0 parts NP-9 and stir evenly at 280 rpm. (2) In the monomer tank, add 0.08 parts of n-dodecyl mercaptan, 12 parts of BA, 3 parts of EA, 13 parts of MMA, 2.5 parts of AN, 2.8 parts of AA, 0.7 parts of GMA and 0.5 parts of AM in sequence, stir well and set aside for use; (3) Prepare a thermal decomposition initiator solution by dissolving 0.24 parts of KPS in 4.56 parts of water to prepare a 5% KPS aqueous solution as the initiator solution; (4) After heating the reaction flask in step (1) to 84°C, add 25wt% initiator solution as the initial initiator, continue stirring for 3 minutes, and then simultaneously add the mixed monomer and the remaining initiator. The addition time is 210 minutes. (5) After the addition is complete, continue stirring at 84℃ and keep warm for 80 minutes to mature; (6) Cool to 40℃, add ammonia to adjust the pH of the emulsion to 7.5, then add 0.2 parts DC-5200, 1.5 parts OT-75, 2.0 parts PAM solution and 2.0 parts DPE in sequence. After the addition is complete, continue stirring for 30 minutes to mix evenly; (7) Add about 5 parts of deionized water to the emulsion to adjust the sugar content of the slurry to 23, filter it in a 250 mesh nylon filter bag, and you can obtain the high toughness and low back adhesion nylon ultrafine denier slurry composition.

[0056] Example 4 This embodiment provides a method for preparing a sizing composition for use in nylon microfiber yarns. The specific steps and methods are as follows: (1) In a reaction flask equipped with a stirrer, condenser, thermometer and dropping device, add 55 parts of deionized water, 0.8 parts of SDBS and 1.2 parts of OP-10, stir evenly at 300 rpm and heat. (2) In a monomer tank, add 0.05 parts of n-dodecyl mercaptan, 13 parts of BA, 2 parts of EHA, 13 parts of MMA, 3 parts of St, 0.5 parts of HPA, 2.5 parts of MAA and 0.5 parts of NMA in sequence, stir evenly and set aside to form a mixed monomer; (3) Prepare a thermal decomposition initiator solution by dissolving 0.3 parts of APS in 5 parts of deionized water to prepare an APS aqueous solution with a mass fraction of 6% as the initiator; (4) After the reaction flask is heated to 84°C, add 20wt% initiator solution as the initial initiator. After stirring for 3 minutes, add the mixed monomer and the remaining initiator dropwise over a period of 210 minutes. (5) After all materials have been added, continue stirring at 62°C for 60 minutes to allow the remaining monomers to continue to react completely. (6) Cool down to 45°C, adjust the pH of the emulsion to 7.5 with ammonia water, and then add 0.3 parts of defoamer SAG638, 1.2 parts of wetting and penetrating agent OT-75, 1 part of antistatic agent glyceryl monostearate and 5 parts of waterborne polyurethane WPU. After the addition is complete, continue to stir for 30 minutes to make it evenly mixed to form an emulsion. (7) Add about 2 parts of deionized water to the emulsion to adjust the sugar content of the slurry to 23, filter it in a 250 mesh nylon filter bag, and the slurry composition can be obtained.

[0057] Example 5 This embodiment provides a method for preparing a sizing composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in Example 1, except that in step (2), 0.5 parts of HPA are replaced with 0.5 parts of NMA.

[0058] Example 6 This embodiment provides a method for preparing a slurry composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in Example 1. The difference is that in step (2), the soft monomer is only BA. That is, (2) In the monomer tank, 0.05 parts of n-dodecyl mercaptan, 15 parts of BA, 13 parts of MMA, 3 parts of St, 0.5 parts of HPA, 2.5 parts of MAA and 0.5 parts of NMA are added in sequence and stirred evenly to form a mixed monomer.

[0059] Example 7 This embodiment provides a method for preparing a sizing composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in Example 1, except that in step (2), the hard monomer is only MMA. That is, (2) in a monomer tank, 0.05 parts of n-dodecyl mercaptan, 13 parts of BA, 2 parts of EHA, 15 parts of MMA, 0.5 parts of HPA, 2.5 parts of MAA and 0.5 parts of NMA are added sequentially and stirred evenly to form a mixed monomer. Example 8 Example 8 This embodiment provides a method for preparing a sizing composition for use in nylon microfiber. The specific steps and methods are the same as in Example 1. The difference is that in step (2), there are only 3.5 parts of MAA as the functional monomer. In step (2), 0.05 parts of n-dodecyl mercaptan, 13 parts of BA, 2 parts of EHA, 13 parts of MMA, 3 parts of St, and 3.5 parts of MAA are added sequentially to the monomer tank and stirred evenly to form a mixed monomer.

[0060] Example 9 This embodiment provides a method for preparing a slurry composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in embodiment 2. The difference is that in step (2), the functional monomers are AA, HEMA and AM. That is, in the monomer tank, 0.03 parts mercaptoethanol, 10 parts BA, 5 parts IOA, 12 parts MMA, 4 parts St, 0.8 parts AA, 1.5 parts HEMA and 1.2 parts AM are added in sequence and stirred evenly to form a mixed monomer.

[0061] Example 10 This embodiment provides a method for preparing a slurry composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in embodiment 2. The difference is that in step (4), the amount of initial initiator is reduced. That is, in step (4), after heating the reaction flask in step (1) to 84°C, 10wt% of initiator solution is added as initial initiator. After stirring for 3 minutes, the mixed monomer and the remaining initiator are added dropwise at the same time. The dropwise addition time is 210 minutes.

[0062] Example 11 This embodiment provides a method for preparing a slurry composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in Example 4, except that step (2) increases the amount of n-dodecyl mercaptan, that is, (2) in the monomer tank, 0.08 parts of n-dodecyl mercaptan, 13 parts of BA, 2 parts of EHA, 13 parts of MMA, 3 parts of St, 0.5 parts of HPA, 2.5 parts of MAA and 0.5 parts of NMA are added in sequence and stirred evenly to form a mixed monomer.

[0063] Example 12 This embodiment provides a method for preparing a sizing composition for use in nylon ultrafine denier yarn. The specific steps and methods are the same as in Example 1, except that the WPU content in step (6) is reduced to 2 parts.

[0064] Example 13 This embodiment provides a method for preparing a sizing composition for use in nylon ultrafine denier filaments. The specific steps and methods are the same as in Example 2, except that the amount of emulsifier is changed to 1.2 parts of AES and 1.8 parts of Pingpingjia O-25.

[0065] Comparative Example 1 This comparative example provides a method for preparing a sizing composition for use in nylon microfiber yarn. The specific steps and methods are the same as in Example 1, except that step (2) does not contain the soft monomers BA and EHA.

[0066] Comparative Example 2 This comparative example provides a method for preparing a sizing composition for use in nylon microfiber yarn. The specific steps and methods are the same as in Example 1, except that step (2) does not contain the functional monomers MAA and NMA.

[0067] Experimental Example The sugar content, pH value, viscosity, elongation at break, tensile strength, rebound tack, and adhesion to nylon of the slurries prepared in Examples 1-16 and Comparative Examples 1-2 were tested according to standards GB / T 1040.3-2006 and FZ / T 15002-2020. The appearance and stability of the emulsions were also evaluated, and the overall condition of the slurries was evaluated. The results are shown in Table 1.

[0068] Table 1. Properties of the slurry

[0069] According to the data in Table 1, compared with Comparative Example 1 (which does not contain soft monomers) and Comparative Example 2 (which does not contain functional monomers), the slurry formed by chain transfer agent, soft monomer, hard monomer, and functional monomer provided in this application exhibits better adhesion to nylon in terms of viscosity, elongation at break, and tensile strength, and lower tackiness. Among them, compared with Example 1, the slurry formed by Example 6 using only one soft monomer, butyl acrylate, has a higher elongation at break, but slightly lower tensile strength and slightly higher tackiness, and the slurry is prone to stickiness; the slurry formed by Example 7 using only one hard monomer, methyl methacrylate, has a slightly lower tensile strength; the slurry formed by Example 8 using only one functional monomer, methacrylic acid, has increased toughness, decreased strength, and slightly increased tackiness. Therefore, the slurry formed by this application using multiple functional monomers, soft monomers, and hard monomers has better elongation at break, tensile strength, and adhesion to nylon, and also has lower tackiness.

[0070] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A sizing composition for use with nylon microfiber filaments, characterized in that, include: Chain transfer agents, soft monomers, hard monomers, and functional monomers, The soft monomers include acrylic compounds containing ester groups. The functional monomers include acrylic compounds containing carbonyl groups.

2. The sizing composition for use in nylon microfiber yarn according to claim 1, characterized in that, The soft monomer includes at least one of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate, preferably butyl acrylate and 2-ethylhexyl acrylate. And / or, the functional monomer includes at least one of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylamide, N-hydroxymethylacrylamide, glycidyl methacrylate, allyl methacrylate, and trimethylolpropane triacrylate, preferably methacrylic acid and N-hydroxymethylacrylamide. And / or, the hard monomer includes at least one of methyl acrylate, methyl methacrylate, styrene, and acrylonitrile.

3. The sizing composition for use in nylon microfiber yarn according to claim 1, characterized in that, The slurry composition further includes water, emulsifier, initiator, toughening agent and additives; And / or, the chain transfer agent is 0.01-0.1 parts by mass, the soft monomer is 5-20 parts by mass, the hard monomer is 5-20 parts by mass, and the functional monomer is 2-10 parts by mass.

4. The sizing composition for use in nylon microfiber yarn according to claim 3, characterized in that, The water has a mass fraction of 50-65 parts; And / or, the emulsifier is present in parts by weight of 1-6 parts; And / or, the chain transfer agent includes at least one of n-dodecyl mercaptan, tert-dodecyl mercaptan, mercaptoethanol, mercaptoacetic acid, and isopropanol; And / or, the emulsifier includes anionic emulsifiers and nonionic emulsifiers; And / or, the toughening agent includes at least one of carboxymethyl starch, polyacrylamide, and waterborne polyurethane, preferably waterborne polyurethane; And / or, the initiator includes at least one of a water-soluble thermal decomposition initiator system or a redox initiator system; And / or, the additives include at least one of neutralizing agents, defoamers, wetting and penetrating agents, and antistatic agents.

5. The sizing composition for use in nylon microfiber yarn according to claim 4, characterized in that, The anionic emulsifier includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, alkyl diphenyl ether disulfonate, sodium alkenyl sulfonate, and sodium succinate sulfonate. And / or, the nonionic emulsifier includes at least one of the following: Pingpingjia O-25, alkylphenol polyoxyethylene ether OP-10, Span 60, polysorbate-20, and nonylphenol polyoxyethylene ether NP-9; And / or, the initiator of the water-soluble thermal decomposition initiator system includes persulfate; And / or, the oxidant in the redox initiator system includes at least one of persulfate and tert-butyl hydroperoxide; And / or, the reducing agent in the redox initiator system includes at least one of sodium bisulfite, sodium metabisulfite, sodium formaldehyde sulfoxylate, triethanolamine, vitamin C, and ascorbic acid; And / or, the neutralizing agent includes at least one of ammonia or sodium hydroxide; And / or, the defoamer includes at least one of mineral oils, organosilicon compounds, or polyether compounds; And / or, the wetting and penetrating agent includes at least one of sodium dioctyl sulfosuccinate and fatty alcohol polyoxyethylene ether; And / or, the antistatic agent includes at least one of nonionic surfactants and anionic surfactants.

6. A method for preparing a sizing composition for use with nylon microfiber as described in any one of claims 1-5, characterized in that, Includes the following steps, In the presence of functional additives, chain transfer agents, soft monomers, hard monomers and functional monomers are mixed to initiate a reaction, forming a sizing composition for use in nylon microfiber filaments.

7. The preparation method according to claim 6, characterized in that, The initiating reaction includes at least one of redox initiating reaction and thermal decomposition initiating reaction; And / or, the functional additives include emulsifiers and initiators.

8. The preparation method according to claim 7, characterized in that, The specific steps of the redox-initiated reaction include: In the presence of an emulsifier solution, an oxidant and a reducing agent are used as initiators to initiate the reaction of chain transfer agents, soft monomers, hard monomers and functional monomers at a reaction temperature of 60-65°C. The oxidant includes at least one of persulfate and tert-butyl hydroperoxide, and the reducing agent includes at least one of sodium bisulfite, sodium metabisulfite, sodium formaldehyde sulfoxylate, triethanolamine and ascorbic acid. And / or, the specific steps of the thermal decomposition initiation reaction include, in the presence of an emulsifier solution, using a water-soluble thermal decomposition initiator as an initiator, initiating the reaction of chain transfer agents, soft monomers, hard monomers and functional monomers at a temperature of 82-86°C, wherein the water-soluble thermal decomposition initiator includes persulfate.

9. The preparation method according to claim 8, characterized in that, In the initiation reaction, the chain transfer agent is 0.01-1 parts by mass, the soft monomer is 5-20 parts by mass, the hard monomer is 5-20 parts by mass, the functional monomer is 2-10 parts by mass, and the emulsifier is 1-6 parts by mass. And / or, the persulfate includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate; And / or, based on the total weight of soft monomers, hard monomers, and functional monomers, the mass of the water-soluble thermal decomposition initiator is 0.2-0.8%; And / or, in the thermal decomposition initiation reaction, a first part by weight of water-soluble thermal decomposition initiator is first added to carry out a primary reaction, and then soft monomers, hard monomers, functional monomers and a second part by weight of water-soluble thermal decomposition initiator are added to carry out a secondary reaction. The mass ratio of the first part by weight of water-soluble thermal decomposition initiator to the second part by weight of water-soluble thermal decomposition initiator is 1-3:7-9. The reaction time of the primary reaction is 2-4 min, and the reaction time of the secondary reaction is 60-210 min, preferably 180-210 min. And / or, in redox-initiated reactions, the amount of oxidant is 0.1-0.4 wt% and the amount of reductant is 0.1-0.5 wt% based on the total weight of the soft monomer, hard monomer, and functional monomer; And / or, after the reaction is initiated, it also includes steps of ripening, adding additives, and adjusting the sugar content of the slurry.

10. The preparation method according to claim 9, characterized in that, The ripening time is 60-100 minutes; And / or, after aging, the temperature of the reaction solution is lowered, and additives are added to it, including neutralizers, defoamers, wetting and penetrating agents, toughening agents, and antistatic agents. The temperature of the reaction solution is lowered to 40-50°C. Based on the mass of the reaction solution, the mass of the defoamer is 0.1-0.5 wt%, the mass of the wetting and penetrating agent is 0.5-2 wt%, the mass of the toughening agent is 1-5 wt%, the mass of the antistatic agent is 0.5-3 wt%, and the neutralizer adjusts the pH value of the reaction solution to 7-8. And / or, the sugar content of the slurry is 20-25; And / or, the concentration of the water-soluble thermal decomposition initiator is 3-10 wt%; And / or, the concentration of the oxidant is 4-10 wt%; And / or, the concentration of the reducing agent is 1-6 wt%.

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