Preparation method of alpha-cyanoacrylate rapid curing fiber

Abstract

The invention relates to the field of polyester fiber materials, and discloses a preparation method of alpha-cyanoacrylate fast-curing fiber, which comprises the following steps: spinning PET resin to prepare PET polyester fiber, and finishing the PET polyester fiber by using a curing finishing agent to prepare the alpha-cyanoacrylate fast-curing fiber. The curing finishing agent contains sodium p-hydroxyphenoxy-macrogol ester, a penetrating agent, a softening agent and a cross-linking agent, the sodium p-hydroxyphenoxy-macrogol ester is alkalescent and can provide hydroxyl so that the alpha-cyanoacrylate can be rapidly cured, and the complete curing time of the alpha-cyanoacrylate can be shortened to 3-5 s; the complete curing time of the alpha-cyanoacrylate is remarkably shortened, and the production efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polyester fiber materials, in particular to a preparation method of α-cyanoacrylate rapid curing fiber. BACKGROUND

[0002] Adhesive compounding is an important means of fiber material compounding, which realizes the bonding of fibers through melting and curing. Adhesives mainly include solvent glue, water-based glue, hot melt glue and α-cyanoacrylate glue. In terms of curing speed, water-based glue has the slowest curing speed, followed by solvent glue, then hot melt glue, and α-cyanoacrylate glue has the fastest curing speed, which can complete preliminary curing within 5-30 seconds. Therefore, α-cyanoacrylate glue is widely used in emergency bonding scenarios.

[0003] Although α-cyanoacrylate glue has fast curing speed, it has low weather resistance and serious whitening problem after curing. Therefore, α-cyanoacrylate is not used in long-term compounding of fibers. The curing speed has a huge impact on production efficiency, and shortening the curing speed can significantly improve the production efficiency. Therefore, it is of great significance to use α-cyanoacrylate with fast curing speed for fiber compounding to improve production efficiency.

[0004] Currently, there are related technical solutions disclosed for improving the weather resistance and reducing the whitening effect of α-cyanoacrylate glue. For example, the publication CN118185482A discloses a kind of moisture and heat resistant instant dry adhesive. In this technical solution, 1,6-hexanediol diacrylate, phthalic anhydride and 4,4-bismaleimide benzhydrazine are added to improve the moisture and heat resistance of the instant dry adhesive. For another example, the publication CN112322219B discloses a composition for reducing the whitening phenomenon of adhesive and adhesive. This technical solution significantly reduces the whitening problem of the adhesive by adding gallnut acid, alkyl ester derivatives of gallnut acid and acid anhydride compounds. The above content can provide important technical inspiration for the application of α-cyanoacrylate in fiber material compounding. In addition, the present application also finds that the fast curing speed of α-cyanoacrylate is reflected in that it can complete preliminary curing within 5-30 seconds, but complete curing still needs a long time. Therefore, its fast curing can only achieve preliminary simple adhesion, and complete curing still needs a long curing time. Therefore, how to shorten the complete curing time of α-cyanoacrylate can effectively achieve the purpose of significantly improving the production efficiency. SUMMARY

[0005] The application provides a preparation method of alpha-cyanoacrylate fast curing fiber.

[0006] The application provides the following technical scheme: The application provides a preparation method of alpha-cyanoacrylate fast curing fiber, which comprises the following steps. (1) polyethylene glycol, p-hydroxybenzoic acid and p-toluene sulfonic acid are added to toluene to perform esterification reaction to prepare polyoxyethylene p-benzoate, then the polyoxyethylene p-benzoate is subjected to saponification reaction with sodium hydroxide to prepare sodium p-hydroxybenzoate-polyethylene glycol ester, and the sodium p-hydroxybenzoate-polyethylene glycol ester, a penetrating agent, a softening agent, a crosslinking agent and water are mixed to prepare a curing finishing agent; (2) PET resin and an additive are blended to prepare PET chips, the PET chips are subjected to melt spinning to prepare PET polyester fiber, and the PET polyester fiber is subjected to oiling and drawing using the curing finishing agent to prepare alpha-cyanoacrylate fast curing fiber.

[0007] Preferably, the molar ratio of polyethylene glycol and p-hydroxybenzoic acid is 1:1.2-1.5.

[0008] Preferably, the amount of p-toluene sulfonic acid is 0.5-2 wt%.

[0009] Preferably, the esterification reaction is performed under the following conditions: temperature 105-115 DEG C, inert gas protection, and reflux dehydration for 2-4 h.

[0010] Preferably, the saponification reaction is performed under the following conditions: temperature 70-90 DEG C, pressure ≤10 KPa, and saponification time 0.5-1 h.

[0011] Preferably, the curing finishing agent comprises 100 parts of mother liquor, 1-3 parts of penetrating agent, 5-12 parts of softening agent and 1-3 parts of crosslinking agent, the mother liquor is an emulsion of sodium p-hydroxybenzoate-polyethylene glycol ester and water, and the content of sodium p-hydroxybenzoate-polyethylene glycol ester in the mother liquor is 15-25 wt%.

[0012] Preferably, the penetrating agent is isomeric fatty alcohol polyoxyethylene ether 7EO, the softening agent is ternary copolymerized silicone oil, and the crosslinking agent is formaldehyde-free melamine.

[0013] Preferably, the mass ratio of PET resin and additive is 100:3-5.

[0014] Preferably, the additives are silane coupling agent KH-550 and calcium stearate.

[0015] As a preferred option, the conditions for oiling and stretching include: oiling nozzle pressure of 0.1 to 0.5 MPa, stretching water bath temperature of 40 to 80°C, total stretching ratio of 1 to 3 times, oven temperature of 100 to 150°C, and machine speed of 30 to 250 m / min.

[0016] This invention provides a method for preparing α-cyanoacrylate rapidly curing fibers. The method involves preparing a curing agent, which is then used to treat PET fibers. This rapidly increases the complete curing speed of α-cyanoacrylate when the PET fibers are bonded together with α-cyanoacrylate, significantly improving the bonding efficiency. The curing agent treatment also enhances the penetration of α-cyanoacrylate onto the fiber surface, enabling the α-cyanoacrylate to quickly wet the fiber surface and improve the uniformity of the α-cyanoacrylate.

[0017] The curing agent provided by this invention uses sodium p-hydroxyphenoxy-polyethylene glycol ester, which is produced by esterification and saponification reactions of polyethylene glycol and p-hydroxybenzoic acid. The chemical formula is shown below: The curing reaction of α-cyanoacrylate is initiated by water and alkaline substances. In actual use, α-cyanoacrylate is rapidly cured by a small amount of moisture in the air. This small amount of moisture allows α-cyanoacrylate to complete initial curing in 5-10 seconds, resulting in low composite strength. Complete curing requires more water, thus taking several tens of minutes, leading to a long production time. This invention addresses these issues by using sodium p-hydroxyphenoxylate (PB-PEG) as a finishing agent for PET polyester fibers. PB-PEG, after film formation, is weakly alkaline and can provide hydroxyl groups to initiate the curing reaction of α-cyanoacrylate. Upon contact with the finishing agent film on the PET fiber surface, α-cyanoacrylate can directly and completely cure, shortening the complete curing time to 3-5 seconds. This significantly reduces the curing time while significantly increasing the composite strength.

[0018] Traditional hot melt adhesives, water-based adhesives, and solvent-based adhesives have high viscosity, so during use, the adhesive cannot penetrate into the pores between fibers. Instead, it forms an adhesive layer on the fiber surface, which binds the fibers together. This is especially problematic when the pore structure of the fabric is small, as the adhesive layer significantly affects the porosity of the fiber fabric. The finishing agent of this invention uses sodium p-hydroxyphenoxyethylene-polyethylene glycol ester and a penetrant. The sodium benzoate groups in sodium p-hydroxyphenoxyethylene-polyethylene glycol ester have a high affinity for PET, and the sodium benzoate groups can generate ionic dipole interactions with the ester bonds of PET, allowing it to adhere to the PET fiber surface. The polyethylene glycol segments in sodium p-hydroxyphenoxyethylene-polyethylene glycol ester have an affinity for α-cyanoacrylate, which can improve the rapid dispersion of α-cyanoacrylate on the surface of the finishing agent film, thereby enabling α-cyanoacrylate to quickly penetrate into the pore structure of the fiber. Furthermore, since sodium p-hydroxyphenoxyethylene-polyethylene glycol ester can rapidly cure α-cyanoacrylate, it is necessary to ensure that α-cyanoacrylate quickly penetrates and is evenly dispersed on the fiber surface before complete curing. In this invention, a penetrant is added during the finishing process. Through the action of the penetrant, α-cyanoacrylate can further penetrate rapidly and evenly to the fiber surface, ensuring the uniformity of α-cyanoacrylate dispersion and reducing the impact of penetration on fiber composites.

[0019] Compared with the prior art, this application has the following technical effects: (1) The present invention uses a curing agent to treat PET polyester fibers to produce α-cyanoacrylate fast-curing fibers, and the resulting fibers can significantly improve the curing speed and permeability of α-cyanoacrylate; (2) The curing agent contains sodium p-hydroxyphenoxy-polyethylene glycol ester, penetrant, softener and crosslinking agent. Sodium p-hydroxyphenoxy-polyethylene glycol ester is weakly alkaline and can provide hydroxyl groups to enable α-cyanoacrylate to complete curing quickly. The time for α-cyanoacrylate to fully cure can be shortened to 3 to 5 seconds. (3) The sodium benzoate group in sodium p-hydroxyphenoxy-polyethylene glycol ester generates an ionic dipole effect with the ester bond of PET polyester, which enables sodium p-hydroxyphenoxy-polyethylene glycol ester to adhere to the PET surface. The polyethylene glycol segment has a high affinity for α-cyanoacrylate, which can improve the permeability of α-cyanoacrylate. The penetrant can further improve the permeability of α-cyanoacrylate, so that α-cyanoacrylate can be quickly and uniformly dispersed on the fiber surface before complete curing, thereby improving the composite strength. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments.

[0021] To better understand the content of this invention, further explanation is provided below with reference to specific embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of this invention.

[0022] Example 1: A method for preparing α-cyanoacrylate fast-curing fibers includes the following steps: (1) Polyethylene glycol (number average molecular weight of 1000, ethylene oxide unit of 22), p-hydroxybenzoic acid, azeotropic solvent toluene and catalyst p-toluenesulfonic acid were added to a container and the container was subjected to esterification reaction for 3 h using a Dean-Stark water separator. The molar ratio of polyethylene glycol to p-hydroxybenzoic acid was 1:1.2, the volume of toluene was twice that of the reaction system, and the amount of p-toluenesulfonic acid added was 0.5 wt%. The esterification reaction was carried out under inert gas and at a temperature of 110 °C. After the esterification reaction product was cooled to 75 °C, it was transferred to a separatory funnel and washed with saturated sodium carbonate solution until neutral to remove p-toluenesulfonic acid and unreacted p-hydroxybenzoic acid. Then it was washed three times with distilled water to separate the organic phase. Anhydrous magnesium sulfate was added to the organic phase for drying. After filtration, residual toluene was removed by vacuum distillation to prepare polyoxyethylene terephthalate. (2) Polyoxyethylene benzoate was saponified using 50% sodium hydroxide aqueous solution. The saponification product was recrystallized by anhydrous ethanol, cooled at 0°C, filtered, and dried under vacuum at 45°C to obtain white sodium p-hydroxyphenoxy-polyethylene glycol ester. The saponification reaction conditions were 80°C, reduced pressure ≤10KPa, and saponification for 1h. (3) Prepare a 15wt% aqueous mother liquor by preparing sodium p-hydroxyphenoxy-polyethylene glycol ester, and then mix 100 parts of aqueous mother liquor, 1 part of penetrant (isomeric fatty alcohol polyoxyethylene ether 7EO), 5 parts of softener (self-emulsifying ternary copolymer silicone oil) and 1 part of crosslinking agent (formaldehyde-free modified melamine) evenly to prepare a curing finishing agent. (4) Weigh PET resin granules and composite additives (silane coupling agent KH-550 and calcium stearate in a mass ratio of 1:1) at a mass ratio of 100:3 and add them to a high-speed mixer. Dry mix at 70°C for 10 minutes until uniformly mixed. Then feed the mixture into a twin-screw extruder and melt extrude in the following zones: Zone 1 180~220°C, Zone 2 250~280°C, Zone 3 250~280°C, Zone 4 250~280°C, Zone 5 250~280°C, Zone 6 250~280°C, Zone 7 250~280°C, Zone 8 250~280°C, Zone 9 250~280°C, Zone 10 250~280°C, and die head 250~280°C. The extruded melt is cooled by water and granulated to make PET chips. (5) After drying the PET chips, they are added to a single screw extruder for melt extrusion. The zone temperature is set as follows: Zone 1: 220-240℃, Zone 2: 250-290℃, Zone 3: 250-290℃, Zone 4: 250-290℃. The melt is injected into the spinning device and extruded to produce PET polyester fiber. The spinning box temperature is 270-300℃. Cooling is performed by air ring blowing at 20℃ and 8m / s. After cooling, the fiber is wound. The winding roller speed is 800m / min, and the feed roller speed is 1.05 times the winding roller speed. (6) The wound PET polyester fiber is stretched, oiled, dried and cut to make α-cyanoacrylate fast curing fiber. The curing agent is evenly sprayed onto the fiber bundle using a 0.25MPa pressure nozzle. The water bath temperature for stretching is 60℃, the total stretching ratio is 1, the oven temperature is 125℃ and the machine speed is 150m / min.

[0023] Example 2: A method for preparing α-cyanoacrylate fast-curing fibers includes the following steps: (1) Polyethylene glycol (number average molecular weight of 1000, ethylene oxide unit of 22), p-hydroxybenzoic acid, azeotropic solvent toluene and catalyst p-toluenesulfonic acid were added to a container and the container was subjected to esterification reaction for 3 h using a Dean-Stark water separator. The molar ratio of polyethylene glycol to p-hydroxybenzoic acid was 1:1.3, the volume of toluene was twice that of the reaction system, and the amount of p-toluenesulfonic acid added was 1 wt%. The esterification reaction was carried out under inert gas and at a temperature of 110 °C. After the esterification reaction product was cooled to 75 °C, it was transferred to a separatory funnel and washed with saturated sodium carbonate solution until neutral to remove p-toluenesulfonic acid and unreacted p-hydroxybenzoic acid. Then it was washed three times with distilled water to separate the organic phase. Anhydrous magnesium sulfate was added to the organic phase for drying. After filtration, residual toluene was removed by vacuum distillation to prepare polyoxyethylene terephthalate. (2) Polyoxyethylene benzoate was saponified using 50% sodium hydroxide aqueous solution. The saponification product was recrystallized by anhydrous ethanol, cooled at 0°C, filtered, and dried under vacuum at 45°C to obtain white sodium p-hydroxyphenoxy-polyethylene glycol ester. The saponification reaction conditions were 80°C, reduced pressure ≤10KPa, and saponification for 1h. (3) Prepare a 20wt% aqueous mother liquor by preparing sodium p-hydroxyphenoxy-polyethylene glycol ester, and then mix 100 parts of aqueous mother liquor, 2 parts of penetrant (isomeric fatty alcohol polyoxyethylene ether 7EO), 8 parts of softener (self-emulsifying ternary copolymer silicone oil) and 2 parts of crosslinking agent (formaldehyde-free modified melamine) evenly to prepare a curing finishing agent. (4) Weigh PET resin granules and composite additives (silane coupling agent KH-550 and calcium stearate in a mass ratio of 1:1) at a mass ratio of 100:4 and add them to a high-speed mixer. Dry mix at 70°C for 12 minutes until uniformly mixed. Then feed the mixture into a twin-screw extruder and melt extrude in the following zones: Zone 1 180~220°C, Zone 2 250~280°C, Zone 3 250~280°C, Zone 4 250~280°C, Zone 5 250~280°C, Zone 6 250~280°C, Zone 7 250~280°C, Zone 8 250~280°C, Zone 9 250~280°C, Zone 10 250~280°C, and die head 250~280°C. The extruded melt is cooled by water and granulated to make PET chips. (5) After drying the PET chips, they are added to a single screw extruder for melt extrusion. The zone temperature is set as follows: Zone 1: 220-240℃, Zone 2: 250-290℃, Zone 3: 250-290℃, Zone 4: 250-290℃. The melt is injected into the spinning device and extruded to produce PET polyester fiber. The spinning box temperature is 270-300℃. Cooling is performed by air ring blowing at 20℃ and 8m / s. After cooling, the fiber is wound. The winding roller speed is 800m / min, and the feed roller speed is 1.05 times the winding roller speed. (6) The wound PET polyester fiber is stretched, oiled, dried and cut to make α-cyanoacrylate fast curing fiber. The curing agent is evenly sprayed onto the fiber bundle using a 0.25MPa pressure nozzle. The water bath temperature for stretching is 60℃, the total stretching ratio is 2 times, the oven temperature is 125℃ and the machine speed is 150m / min.

[0024] Example 3: A method for preparing α-cyanoacrylate fast-curing fibers includes the following steps: (1) Polyethylene glycol (number average molecular weight of 1000, ethylene oxide unit of 22), p-hydroxybenzoic acid, azeotropic solvent toluene and catalyst p-toluenesulfonic acid were added to a container and the container was subjected to esterification reaction for 30 h using a Dean-Stark water separator. The molar ratio of polyethylene glycol to p-hydroxybenzoic acid was 1:1.4, the volume of toluene was twice that of the reaction system, and the amount of p-toluenesulfonic acid added was 1.5 wt%. The esterification reaction was carried out under inert gas and at a temperature of 110 °C. After the esterification reaction product was cooled to 70-80 °C, it was transferred to a separatory funnel and washed with saturated sodium carbonate solution until neutral to remove p-toluenesulfonic acid and unreacted p-hydroxybenzoic acid. Then it was washed three times with distilled water to separate the organic phase. Anhydrous magnesium sulfate was added to the organic phase for drying. After filtration, residual toluene was removed by vacuum distillation to prepare polyoxyethylene terephthalate. (2) Polyoxyethylene benzoate was saponified using 50% sodium hydroxide aqueous solution. The saponification product was recrystallized by anhydrous ethanol, cooled at 0°C, filtered, and dried under vacuum at 45°C to obtain white sodium p-hydroxyphenoxy-polyethylene glycol ester. The saponification reaction conditions were 80°C, reduced pressure ≤10KPa, and saponification for 1h. (3) Prepare a 25wt% aqueous mother liquor by mixing 100 parts of aqueous mother liquor, 3 parts of penetrant (isomeric fatty alcohol polyoxyethylene ether 7EO), 12 parts of softener (self-emulsifying ternary copolymer silicone oil) and 3 parts of crosslinking agent (formaldehyde-free modified melamine) evenly to prepare a curing finishing agent. (4) Weigh PET resin granules and composite additives (silane coupling agent KH-550 and calcium stearate in a mass ratio of 1:1) at a mass ratio of 100:5 and add them to a high-speed mixer. Dry mix at 70°C for 12 minutes until uniformly mixed. Then feed the mixture into a twin-screw extruder and melt extrude in the following zones: Zone 1 180~220°C, Zone 2 250~280°C, Zone 3 250~280°C, Zone 4 250~280°C, Zone 5 250~280°C, Zone 6 250~280°C, Zone 7 250~280°C, Zone 8 250~280°C, Zone 9 250~280°C, Zone 10 250~280°C, and die head 250~280°C. The extruded melt is cooled by water and granulated to make PET chips. (5) After drying the PET chips, they are added to a single screw extruder for melt extrusion. The zone temperature is set as follows: Zone 1: 220-240℃, Zone 2: 250-290℃, Zone 3: 250-290℃, Zone 4: 250-290℃. The melt is injected into the spinning device and extruded to produce PET polyester fiber. The spinning box temperature is 270-300℃. Cooling is performed by air ring blowing at 20℃ and 8m / s. After cooling, the fiber is wound. The winding roller speed is 800m / min, and the feed roller speed is 1.05 times the winding roller speed. (6) The wound PET polyester fiber is stretched, oiled, dried and cut to make α-cyanoacrylate fast curing fiber. The curing agent is evenly sprayed onto the fiber bundle using a 0.25MPa pressure nozzle. The water bath temperature for stretching is 60℃, the total stretching ratio is 3 times, the oven temperature is 125℃ and the machine speed is 150m / min.

[0025] Example 4 A method for preparing α-cyanoacrylate fast-curing fibers includes the following steps: (1) Polyethylene glycol (number average molecular weight of 1000, ethylene oxide unit of 22), p-hydroxybenzoic acid, azeotropic solvent toluene and catalyst p-toluenesulfonic acid were added to a container and the container was subjected to esterification reaction for 3 h using a Dean-Stark water separator. The molar ratio of polyethylene glycol to p-hydroxybenzoic acid was 1:1.5, the volume of toluene was twice that of the reaction system, and the amount of p-toluenesulfonic acid added was 2 wt%. The esterification reaction was carried out under inert gas and at a temperature of 110 °C. After the esterification reaction product was cooled to 75 °C, it was transferred to a separatory funnel and washed with saturated sodium carbonate solution until neutral to remove p-toluenesulfonic acid and unreacted p-hydroxybenzoic acid. Then it was washed three times with distilled water to separate the organic phase. Anhydrous magnesium sulfate was added to the organic phase for drying. After filtration, the residual toluene was removed by vacuum distillation to prepare polyoxyethylene terephthalate. (2) Polyoxyethylene benzoate was saponified using 50% sodium hydroxide aqueous solution. The saponification product was recrystallized by anhydrous ethanol, cooled at 0°C, filtered, and dried under vacuum at 45°C to obtain white sodium p-hydroxyphenoxy-polyethylene glycol ester. The saponification reaction conditions were 80°C, reduced pressure ≤10KPa, and saponification for 1h. (3) Prepare a 25wt% aqueous mother liquor by mixing 100 parts of aqueous mother liquor, 2 parts of penetrant (isomeric fatty alcohol polyoxyethylene ether 7EO), 8 parts of softener (self-emulsifying ternary copolymer silicone oil) and 2 parts of crosslinking agent (formaldehyde-free modified melamine) evenly to prepare a curing finishing agent. (4) Weigh PET resin granules and composite additives (silane coupling agent KH-550 and calcium stearate in a mass ratio of 1:1) at a mass ratio of 100:5 and add them to a high-speed mixer. Dry mix at 70°C for 15 minutes until uniformly mixed. Then feed the mixture into a twin-screw extruder and melt extrude in the following zones: Zone 1 180~220°C, Zone 2 250~280°C, Zone 3 250~280°C, Zone 4 250~280°C, Zone 5 250~280°C, Zone 6 250~280°C, Zone 7 250~280°C, Zone 8 250~280°C, Zone 9 250~280°C, Zone 10 250~280°C, and die head 250~280°C. The extruded melt is cooled by water and granulated to make PET chips. (5) After drying the PET chips, they are added to a single screw extruder for melt extrusion. The zone temperature is set as follows: Zone 1: 220-240℃, Zone 2: 250-290℃, Zone 3: 250-290℃, Zone 4: 250-290℃. The melt is injected into the spinning device and extruded to produce PET polyester fiber. The spinning box temperature is 270-300℃. Cooling is performed by air ring blowing at 25℃ and 10m / s. After cooling, the fiber is wound. The winding roller speed is 1200m / min, and the feed roller speed is 1.1 times the winding roller speed. (6) The wound PET polyester fiber is stretched, oiled, dried and cut to make α-cyanoacrylate fast curing fiber. The curing agent is evenly sprayed on the fiber bundle using a 0.5MPa pressure nozzle. The water bath temperature for stretching is 80℃, the total stretching ratio is 3 times, the oven temperature is 150℃ and the machine speed is 250m / min.

[0026] Example 5: A method for preparing α-cyanoacrylate fast-curing fibers includes the following steps: (1) Polyethylene glycol (number average molecular weight of 1000, ethylene oxide unit of 22), p-hydroxybenzoic acid, azeotropic solvent toluene and catalyst p-toluenesulfonic acid were added to a container and the container was subjected to esterification reaction for 3 h using a Dean-Stark water separator. The molar ratio of polyethylene glycol to p-hydroxybenzoic acid was 1:1.5, the volume of toluene was twice that of the reaction system, and the amount of p-toluenesulfonic acid added was 1.5 wt%. The esterification reaction was carried out under inert gas and at a temperature of 110 °C. After the esterification reaction product was cooled to 70 °C, it was transferred to a separatory funnel and washed with saturated sodium carbonate solution until neutral to remove p-toluenesulfonic acid and unreacted p-hydroxybenzoic acid. Then it was washed three times with distilled water to separate the organic phase. Anhydrous magnesium sulfate was added to the organic phase for drying. After filtration, residual toluene was removed by vacuum distillation to prepare polyoxyethylene terephthalate. (2) Polyoxyethylene benzoate was saponified using a 50% sodium hydroxide aqueous solution. The saponified product was recrystallized from anhydrous ethanol, cooled at 5°C, filtered, and vacuum dried at 40°C to obtain white sodium p-hydroxyphenoxy-polyethylene glycol ester. The saponification reaction conditions were 70°C, reduced pressure ≤10KPa, and saponification time 0.5h. (3) Prepare a 20wt% aqueous mother liquor by preparing sodium p-hydroxyphenoxy-polyethylene glycol ester, and then mix 100 parts of aqueous mother liquor, 1 part of penetrant (isomeric fatty alcohol polyoxyethylene ether 7EO), 5 parts of softener (self-emulsifying ternary copolymer silicone oil) and 1 part of crosslinking agent (formaldehyde-free modified melamine) evenly to prepare a curing finishing agent. (4) Weigh PET resin granules and composite additives (silane coupling agent KH-550 and calcium stearate in a mass ratio of 1:1) at a mass ratio of 100:3-5 and add them to a high-speed mixer. Dry mix at 60°C for 10 minutes until uniformly mixed, and then feed them into a twin-screw extruder. Melt extrusion is performed in the following zones: Zone 1 180-220°C, Zone 2 250-280°C, Zone 3 250-280°C, Zone 4 250-280°C, Zone 5 250-280°C, Zone 6 250-280°C, Zone 7 250-280°C, Zone 8 250-280°C, Zone 9 250-280°C, Zone 10 250-280°C, and die head 250-280°C. The extruded melt is cooled by water and granulated to make PET chips. (5) After drying the PET chips, they are added to a single screw extruder for melt extrusion. The zone temperature is set as follows: Zone 1: 220-240℃, Zone 2: 250-290℃, Zone 3: 250-290℃, Zone 4: 250-290℃. The melt is injected into the spinning device and extruded to produce PET polyester fiber. The spinning box temperature is 270-300℃. It is cooled by air blowing at 15-25℃ and 2-10m / s. After cooling, it is wound. The winding roller speed is 800m / min, and the feed roller speed is 1.02 times the winding roller speed. (6) The wound PET polyester fiber is stretched, oiled, dried and cut to make α-cyanoacrylate fast curing fiber. The curing agent is evenly sprayed onto the fiber bundle using a 0.1MPa pressure nozzle. The water bath temperature for stretching is 40℃, the total stretching ratio is 3 times, the oven temperature is 100℃ and the machine speed is 30m / min.

[0027] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that sodium p-hydroxyphenoxyethylene-polyethylene glycol ester was not added to the finishing agent; all other conditions were the same as in Example 1.

[0028] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that no penetrant was added; all other conditions were the same as in Example 1.

[0029] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that no curing agent was used on the PET polyester fiber, while all other conditions were the same as in Example 1.

[0030] Example of detection: PET polyester fibers obtained in Examples 1-5 and Comparative Examples 1-3 were used to make fiber fabrics. The fiber fabrics were then laminated with adhesives, and the adhesives selected were α-cyanoacrylate (502 glue), hot melt adhesive (TPU hot melt adhesive), and water-based polyurethane adhesive. The composite strength, complete curing time, and air permeability of the fiber fabrics were tested. Shear strength was tested in accordance with GB / T 33334-2016 "Test Method for Tensile Shear Strength of Single Lap Joint of Adhesive". The curing time of α-cyanoacrylate was tested in accordance with the standard "HG / T 2492-2018 Ethyl α-cyanoacrylate Instant Adhesive". The curing time of TPU hot melt adhesive was tested in accordance with "HG / T 3716-2003 Determination of Open Time of Hot Melt Adhesive". Waterborne polyurethane adhesives were tested in accordance with GB / T 12954-1991 General Test Methods for Building Adhesives; Air permeability was tested in accordance with GB / T 5453-1997 "Determination of air permeability of textile fabrics"; The test results are shown in Table 1; Table 1 Performance Test Results As shown in Table 1, when the fiber fabric made from the α-cyanoacrylate rapid-curing fiber obtained in this invention is laminated with α-cyanoacrylate, the complete curing time of α-cyanoacrylate reaches 3-5 seconds. The shear strength of the laminated fiber fabric is 12.3-12.5 MPa, and the air permeability is 0.043-0.045 L / m. 2 •s; When using TPU hot melt adhesive to laminate fiber fabrics, the curing time of the TPU hot melt adhesive is 30s. The shear strength of the laminated fiber fabric is 11.1~11.3MPa, and the air permeability of the laminated fiber fabric is 0.028L / m². 2 •s; When using solvent-based polyurethane adhesives to laminate fiber fabrics, the curing time of the solvent-based polyurethane adhesive is 30 min, the shear strength of the laminated fiber fabric is 10.7–10.8 MPa, and the air permeability of the laminated fiber fabric is 0.025 L / m. 2 ·s; The above results show that the rapid-curing fiber prepared by the present invention can significantly improve the complete curing time of α-cyanoacrylate, and the composite strength of the fabric made of polyester fiber is also significantly improved. Moreover, the adhesive has no significant effect on the air permeability of the fiber textile. In contrast, the air permeability of the fiber textile is significantly reduced after using traditional hot melt adhesives and solvent-based adhesives to composite the fiber textile, which has a significant adverse effect on the air permeability of the fiber textile. In addition, both hot melt adhesives and solvent-based adhesives require the adhesive to be applied to the surface of the fiber textile before composite. Hot melt adhesives require heating the adhesive, and solvent-based adhesives require the solvent to evaporate after composite. Both are complicated to use. However, the fabric made of the rapid-curing fiber of the present invention only requires the fibers to be stacked and then α-cyanoacrylate sprayed onto the stacked fibers. α-cyanoacrylate can penetrate to the fiber surface through the pores of the fibers and complete the rapid composite of the fiber textile.

[0031] Comparative Example 1 is a technical solution without the addition of sodium p-hydroxyphenoxylate-polyethylene glycol ester. The results show that when polyester fiber fabrics are laminated with α-cyanoacrylate without the addition of sodium p-hydroxyphenoxylate-polyethylene glycol ester in the finishing agent, the complete curing time of the fiber fabrics reaches 300s (ten minutes). It can be seen that sodium p-hydroxyphenoxylate-polyethylene glycol ester can significantly shorten the complete curing speed of α-cyanoacrylate. In addition, the shear strength of the fiber fabrics after lamination in Comparative Example 1 is only 8.8MPa, which is significantly lower than the lamination strength in Example 1. This indicates that sodium p-hydroxyphenoxylate-polyethylene glycol ester can also significantly enhance the lamination strength of the fiber fabrics.

[0032] In Comparative Example 2, no penetrant was added, and the results showed that the composite strength of the fiber fabric was only 5.3 MPa. After analysis, it was found that because no penetrant was added to the finishing agent and the curing speed of α-cyanoacrylate was relatively fast, the α-cyanoacrylate had not completely diffused to the fiber surface before it was cured, which led to a significant reduction in the composite strength of the fiber fabric.

[0033] In Comparative Example 3, the fiber fabric was not treated with a curing agent. The results showed that the composite strength of the fiber fabric was only 8.2 MPa, and the complete curing speed of α-cyanoacrylate was 300 s. This result indicates that after the polyester fiber was treated with a curing agent according to the present invention, the curing speed of α-cyanoacrylate was significantly shortened when the fiber fabric was composited with α-cyanoacrylate, and the composite strength of the fiber fabric was significantly improved.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing α-cyanoacrylate fast-curing fibers, characterized in that, Includes the following steps: (1) Polyethylene glycol, p-hydroxybenzoic acid and p-toluenesulfonic acid are added to toluene for esterification reaction to prepare polyoxyethylene terephthalate, and then polyoxyethylene terephthalate is saponified with sodium hydroxide to prepare sodium p-hydroxyphenoxy-polyethylene glycol ester. Sodium p-hydroxyphenoxy-polyethylene glycol ester, penetrant, softener, crosslinking agent and water are mixed to prepare curing finishing agent; (2) PET resin and additives are blended to form PET chips, and the PET chips are melt-spun to form PET polyester fibers. The PET polyester fibers are oiled and stretched using a curing agent to form α-cyanoacrylate fast-curing fibers.

2. The preparation method according to claim 1, characterized in that, The molar ratio of polyethylene glycol to p-hydroxybenzoic acid is 1:1.2~1.

5.

3. The preparation method according to claim 1, characterized in that, The dosage of p-toluenesulfonic acid is 0.5~2 wt%.

4. The preparation method according to claim 1, characterized in that, The conditions for the esterification reaction include: temperature 105~115 ℃, inert gas protection, and reflux dehydration for 2~4 h.

5. The preparation method according to claim 1, characterized in that, The conditions for the saponification reaction include: temperature 70~90 ℃, pressure ≤10 KPa, and saponification time 0.5~1 h.

6. The preparation method according to claim 1, characterized in that, The curing agent, by weight, consists of 100 parts of mother liquor, 1-3 parts of penetrant, 5-12 parts of softener, and 1-3 parts of crosslinking agent. The mother liquor is an emulsion of sodium p-hydroxyphenoxylate, polyethylene glycol ester, and water, and the content of sodium p-hydroxyphenoxylate, polyethylene glycol ester in the mother liquor is 15-25 wt%.

7. The preparation method according to claim 1 or 6, characterized in that, The penetrant is isomeric fatty alcohol polyoxyethylene ether 7EO, the softener is ternary copolymer silicone oil, and the crosslinking agent is formaldehyde-free melamine.

8. The preparation method according to claim 1, characterized in that, The mass ratio of PET resin to additives is 100:3~5.

9. The preparation method according to claim 1 or 8, characterized in that, The additives are silane coupling agent KH-550 and calcium stearate.

10. The preparation method according to claim 1, characterized in that, The conditions for oiling and stretching include: oiling nozzle pressure 0.1~0.5 MPa, stretching water bath temperature 40~80 ℃, total stretching ratio 1~3 times, oven temperature 100~150 ℃, and machine speed 30~250m / min.

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