CN116219571A - High resilience and anti-creep copolymerized nylon monofilament and its preparation method and application - Google Patents

Abstract

The application discloses a high-resilience creep-resistant copolymerized nylon monofilament and a preparation method and application thereof, wherein inorganic nano particles are subjected to surface modification through a silane coupling agent, the modified nano particles and copolyamide are uniformly mixed, and then the mixture is added into a double-screw extruder for melt blending and extrusion, and a melt extrusion wire is cooled through cooling liquid to form a primary wire; and (5) stretching the primary yarn twice, and shaping. According to the technical scheme provided by the embodiment of the application, the inorganic nano particles are provided and are subjected to surface modification through the silane coupling agent, so that the surface effect of the nano particles is improved, the dispersibility of the nano particles in a polymer matrix is improved, meanwhile, the terminal epoxy group of the coupling agent is subjected to graft copolymerization with the amine group of the copolyamide, the molecular chain of the polyamide is prolonged, the movement of the molecular chain is greatly limited, and the creep effect of the polymer monofilament is further reduced.

Description

High resilience and creep resistance copolymer nylon monofilament and its preparation method and application

Technical Field

The invention generally relates to the field of monofilaments, and in particular to high-resilience and creep-resistant copolymer nylon monofilaments and a preparation method and application thereof.

Background Art

The use of copolymerized polyamide PA6/66 monofilament as fishing line requires the following indicators: high transparency, good softness, high strength, and good toughness. In order to achieve this goal, there are many related studies, such as: simply using inorganic nano additives and polyamide for melt blending. Since inorganic nano particles are easy to agglomerate in the polymer matrix and agglomerate into larger particles, they do not play a role in improving resilience, but instead become stress concentration points, reducing their original performance. In addition, there are many modified products that use organic nucleating agents, plasticizers, etc. It is difficult to obtain monofilament products with high strength, good softness and smoothness, good resilience, and good transparency at the same time by adding these additives.

Summary of the invention

In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a high-resilience and creep-resistant copolymer nylon monofilament and a preparation method and application thereof.

In a first aspect, a method for preparing a high resilience creep resistant copolymer nylon monofilament is provided, comprising the steps of:

S10: providing inorganic nanoparticles, and performing surface modification on the inorganic nanoparticles by using a silane coupling agent to form modified nanoparticles,

S20: after uniformly mixing the modified nanoparticles and the copolyamide, adding them into a twin-screw extruder for melt blending and extrusion, the mass score of the modified nanoparticles is 1-2, and the mass score of the copolyamide is 98-99.

S30: The molten extruded filament is cooled by a coolant, wherein the temperature of the coolant is less than or equal to 0° C., and then drawn and wound to form a raw filament;

S40: The spun yarn is stretched twice, wherein the first stretching is steam stretching with a stretching ratio of 3-4 times, and the second stretching is hot air stretching with a stretching ratio of 1.1-1.5 times, and then a shaping treatment is performed to form a high resilience and creep resistant copolymer nylon monofilament.

In a second aspect, a method for preparing the above-mentioned high resilience and creep resistant copolymer nylon monofilament is provided to prepare the copolymer nylon monofilament.

In a third aspect, an application of the above-mentioned copolymer nylon monofilament is provided.

According to the technical solution provided in the embodiments of the present application, inorganic nanoparticles are provided and surface modified by a silane coupling agent to improve the surface effect of the nanoparticles and the dispersibility of the nanoparticles in the polymer matrix. At the same time, the terminal epoxy group of the coupling agent also undergoes a graft copolymerization reaction with the amine group of the copolymerized polyamide, thereby extending the molecular chain of the polyamide, greatly restricting the movement of the molecular chain, and further reducing the creep effect of the polymer monofilament, thereby improving the elastic recovery rate of the fiber and obtaining a high-resilience nylon monofilament.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

FIG. 1 is a flow chart of the method for preparing high resilience creep resistant copolymer nylon monofilament in this embodiment.

DETAILED DESCRIPTION

The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant inventions, rather than to limit the inventions. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

Please refer to FIG1 , this embodiment provides a method for preparing high resilience creep resistant copolymer nylon monofilament, comprising the steps of:

S10: providing inorganic nanoparticles, and performing surface modification on the inorganic nanoparticles by using a silane coupling agent to form modified nanoparticles,

S20: after uniformly mixing the modified nanoparticles and the copolyamide, adding them into a twin-screw extruder for melt blending and extrusion, the mass score of the modified nanoparticles is 1-2, and the mass score of the copolyamide is 98-99.

S30: The molten extruded filament is cooled by a coolant, wherein the temperature of the coolant is less than or equal to 0° C., and then drawn and wound to form a raw filament;

S40: The spun yarn is stretched twice, wherein the first stretching is steam stretching with a stretching ratio of 3-4 times, and the second stretching is hot air stretching with a stretching ratio of 1.1-1.5 times, and then a shaping treatment is performed to form a high resilience and creep resistant copolymer nylon monofilament.

This embodiment improves the surface effect of the nanoparticles and the dispersibility of the nanoparticles in the polymer matrix by providing inorganic nanoparticles and performing surface modification on the inorganic nanoparticles through a silane coupling agent. At the same time, the terminal epoxy group of the coupling agent also undergoes a graft copolymerization reaction with the amine group of the copolymerized polyamide, thereby extending the molecular chain of the polyamide, greatly restricting the movement of the molecular chain, and further reducing the creep effect of the polymer monofilament, thereby improving the elastic recovery rate of the fiber and obtaining a high-resilience nylon monofilament.

Firstly, an inorganic nanoparticle is provided, and the surface of the inorganic nanoparticle is modified by a silane coupling agent, wherein the selected inorganic nanoparticle is spherical, rod-shaped or layered. The shape of the selected nanoparticle has no necessary connection with the operation steps, and different shapes can be selected.

Optionally, the inorganic nanoparticles are one or more of inorganic nano-TiO2, inorganic nano-SiO2, nano-CaCO3, nano-whiskers, nano-attapulgite, silicate, and vermiculite. In the present embodiment, inorganic nanomaterials are selected for surface modification. There are various inorganic nanomaterials that can be selected. Preferably, one or more of the above-mentioned materials are used to improve the dispersibility of the inorganic nanoparticles in the polymer matrix through a silane coupling agent, so that the modified inorganic nanoparticles can be fully dispersed in the copolyamide, fully mixed with the copolyamide, and react with it.

Specific surface modification of inorganic nanoparticles includes:

S11: fully mixing the inorganic nanoparticles with a 75% by mass ethanol solution, wherein the mass ratio of the inorganic nanoparticles to the ethanol solution is 5-10:100;

S12: adding the silane coupling agent to the mixed solution, adjusting the pH of the mixed solution with sodium hydroxide until the pH value is 7-9, and the amount of the silane coupling agent added is 1-3% of the mass of the inorganic nanoparticles;

S13: heating the mixed solution to 75-85° C., keeping the temperature and stirring for 6-8 hours;

S14: centrifuging the mixed solution after the insulation to obtain modified nanoparticles.

The inorganic nanoparticles are fully mixed with an ethanol solution, the solvent of the ethanol solution is water, and then a silane coupling agent is added, and the pH value is adjusted by adding sodium hydroxide. After the adjustment, the solution is stirred evenly to obtain a first mixed solution, and then the first mixed solution is heated in a slowly increasing temperature manner. After being kept warm and stirred for a period of time, a second mixed solution is obtained. Since the silane coupling agent is easily grafted onto the nanoparticles in an alkaline environment, the grafting rate is the highest, thereby obtaining modified nanoparticles with the highest grafting rate;

The second mixed solution is centrifuged to obtain a solid, that is, a modified nanomaterial. After obtaining the solid product, it needs to be dried and ground to grind the modified nanoparticles to the required particle size so that they are more evenly distributed in the copolymer polyamide.

Further, the silane coupling agent is one of KH550, KH560, and KH570. In this embodiment, there are many types of silane coupling agents, but different silane coupling agents have different surface modification effects on inorganic nanoparticles. For example, KH560 is selected as the coupling agent. The terminal group of the coupling agent is an epoxy group, which can improve the surface effect of the nanoparticles and improve the dispersibility of the nanoparticles in the polymer matrix. At the same time, the terminal epoxy group of KH560 also undergoes graft copolymerization reaction with the amino group of the copolymerized polyamide, extending the surface modification effect of the inorganic nanoparticles. The molecular chain of polyamide is lengthened, which greatly limits the movement of the molecular chain and further reduces the creep effect of the polymer monofilament, thereby improving the elastic recovery rate of the fiber; KH550 is selected as the coupling agent, and the terminal group of the coupling agent is amino, which forms hydrogen bonds with the terminal hydroxyl groups of polyamide, and can also achieve the effect of surface modification, but the hydrogen bond force is not as strong as the covalent bond force. The product produced is slightly worse than the modification effect of the coupling agent KH560. Therefore, KH560 is preferably used as the silane coupling agent for surface modification.

Preferably, the viscosity of the copolyamide is 2.4-3.2. The viscosity of the copolyamide in this embodiment is conducive to forming a monofilament with high strength and high elastic recovery rate.

The inorganic nanoparticles are preferably _SiO2 particles, and the silane coupling agent is KH560 coupling agent. The following chemical formula shows that the coupling agent KH560 modifies SiO2 so that the end groups of _SiO2 particles are modified into epoxy groups, which undergo graft copolymerization reaction with copolyamide.

Then, the modified nanoparticles are mixed evenly with the copolymerized polyamide and added to a twin-screw extruder for melt blending and extrusion. The outlet of the twin-screw extruder used in this embodiment is conical, and the screw temperature is 235-255° C.;

The melt-extruded filaments need to be cooled by a coolant. The temperature of the coolant is preferably set to be less than or equal to 0°C. The coolant is used for quenching so that the ejected filaments hardly crystallize in the coolant and maintain an unstable crystal structure. This structure is more convenient for the subsequent stretching process and can ultimately obtain a copolymer polyamide monofilament product with high strength, high elastic recovery rate, good transparency, and high softness and smoothness. In this embodiment, an alcohol liquid, such as ethanol, is preferably used as the coolant.

The formed spun yarn is stretched in two stages: the first stage is steam stretching, in which the spun yarn is stretched in a 100°C steam water tank with a stretching ratio of 3-4 times; the second stage is hot air stretching, in which the spun yarn is stretched in a hot air stretching oven with a temperature set at 150-200°C and a stretching ratio of 1.1-1.5 times; and finally, a shaping treatment is performed at a shaping treatment temperature of 150-210°C to obtain a copolymer nylon monofilament product, which is then rolled up and stored.

This embodiment also provides a high resilience and creep resistance copolymer nylon monofilament made by the above method, which has the characteristics of high strength, high elastic recovery rate, good transparency, and high softness and smoothness.

The copolymer nylon monofilament is applied to fishing lines and used as fishing lines, and has the characteristics of good softness, high strength and good toughness.

According to the above method, three embodiments and nine comparative examples are given below, and the single filament breaking strength, single filament elongation, knot ratio and elastic recovery rate of the embodiments and comparative examples are tested:

Embodiment 1:

Step 1: Surface modification of inorganic nano-SiO2

Add nano-SiO2 and 75% ethanol solution (solvent is water) into the reactor, the mass ratio of the two is 5:100, and then add KH560, the amount of which is 1% of the mass fraction of nano-SiO2, adjust the pH value to 7--9, stir well to obtain mixed system A, and then slowly heat to 75-85℃, keep warm and stir for 6 hours to obtain mixed system B. Centrifuge the mixed system B to obtain product C, and then cool, dry, and grind to obtain modified nano-SiO2 with a particle size of 10-20μm.

Step 2: Copolymerization and grafting reaction of modified nano-SiO2 and copolymerized polyamide

The modified nano-SiO2 powder particles obtained in step 1, with a content of 1%, and a copolymerized polyamide PA6/66 with a content of 99% are first mixed at high speed in a high-speed mixer, and then added together into a conical twin-screw extruder for melt blending and extrusion, wherein the screw temperature is 255°C, the spinneret specification is 0.8*32H, and the metering pump speed is 8r/min. Then, the powder particles are quenched by a high-boiling alcohol liquid with a coolant temperature of -10°C, and then passed through a drawing machine and reeled to obtain spun yarn. The spun yarn is then passed through a 100°C steam water tank for one stretching with a stretching ratio of 5 times, and then passed through a hot air stretching oven with a temperature set to 180°C and a second stretching ratio of 1.25 times. Finally, the spun yarn is subjected to a shaping treatment and reeled to obtain a PA6/66 monofilament product with a shaping treatment temperature of 200°C.

Embodiment 2:

Step 1: Surface modification of inorganic nano-SiO2

Add nano-SiO2 and 75% ethanol solution (solvent is water) into the reactor, mix them thoroughly at a mass ratio of 8:100, then add KH550 in an amount of 2% of the mass fraction of nano-SiO2, adjust the pH value to 7--9 and stir thoroughly to obtain mixed system A. Then slowly heat to 75-85°C, keep warm and stir for 7 hours to obtain mixed system B. Centrifuge mixed system B to obtain product C, then cool, dry, and grind to obtain modified nano-SiO2 with a particle size of 10-20μm. Step 2. Copolymerization and grafting reaction of modified nano-SiO2 and copolymerized polyamide

Step 2: Copolymerization and grafting reaction of modified nano-SiO2 and copolymerized polyamide

The modified nano-SiO2 powder particles obtained in step 1, with a content of 1.5%, and a copolymerized polyamide PA6/66 with a content of 98.5% are first mixed at high speed in a high-speed mixer, and then added together into a conical twin-screw extruder for melt blending and extrusion, wherein the screw temperature is 255°C, the spinneret specification is 0.8*32H, and the metering pump speed is 8r/min. Then, the particles are quenched by a high-boiling alcohol liquid with a coolant temperature of -10°C, and then passed through a drawing machine and reeled to obtain spun yarn. The spun yarn is then passed through a 100°C steam water tank and stretched once, with a stretching ratio of 5 times. Then, the spun yarn is passed through a hot air stretching oven, with the temperature set to 180°C and a second stretching ratio of 1.25 times. Finally, the spun yarn is subjected to a shaping treatment and reeled to obtain a PA6/66 monofilament product, and the shaping treatment temperature is 200°C.

Embodiment three:

Step 1: Surface modification of inorganic nano-SiO2

Add nano-SiO2 and 75% ethanol solution (solvent is water) into the reactor, the mass ratio of the two is 10:100, and then add KH570, the amount of which is 3% of the mass fraction of nano-SiO2, adjust the pH value to 7--9 and stir well to obtain mixed system A. Then slowly heat up to 75-85°C, keep warm and stir for 8 hours to obtain mixed system B. Centrifuge mixed system B to obtain product C, then cool, dry, and grind to obtain modified nano-SiO2 with a particle size of 10-20μm. Step 2. Copolymerization and grafting reaction of modified nano-SiO2 and copolymerized polyamide

Step 2: Copolymerization and grafting reaction of modified nano-SiO2 and copolymerized polyamide

The modified nano-SiO2 powder particles obtained in step 1, with a content of 2%, and a copolymerized polyamide PA6/66 with a content of 98% are first mixed at high speed in a high-speed mixer, and then added together into a conical twin-screw extruder for melt blending and extrusion, wherein the screw temperature is 255°C, the spinneret specification is 0.8*32H, and the metering pump speed is 8r/min. Then, the powder particles are quenched by a high-boiling alcohol liquid with a coolant temperature of -10°C, and then passed through a drawing machine and reeled to obtain spun yarn. The spun yarn is then passed through a 100°C steam water tank for one stretching with a stretching ratio of 5 times, and then passed through a hot air stretching oven with a temperature set to 180°C and a second stretching ratio of 1.25 times. Finally, the spun yarn is subjected to a shaping treatment and reeled to obtain a PA6/66 monofilament product with a shaping treatment temperature of 200°C.

Comparative Example 1:

In step 1, the mass ratio of nano-SiO2 to ethanol solution is 3:100, and other process conditions are the same as those in Example 1.

Comparative Example 2:

In step 1, the mass ratio of nano-SiO2 to ethanol solution is 15:100, and other process conditions are the same as those in Example 1.

Comparative Example 3:

The coupling agent added in step 1 is a titanate coupling agent, and other process conditions are the same as those in Example 1.

Comparative Example 4:

The amount of KH550 added in step 1 is 0.5% of the mass fraction of nano-SiO2, and other process conditions are the same as those in embodiment 1.

Comparative Example 5:

The amount of KH550 added in step 1 is 4% of the mass fraction of nano-SiO2, and other process conditions are the same as those in embodiment 1.

Comparative Example 6:

The stirring reaction time in step 1 is 5 hours, and other process conditions are the same as those in Example 1.

Comparative Example 7:

The stirring reaction time in step 1 is 10 hours, and other process conditions are the same as those in Example 1.

Comparative Example 8:

In step 2, the amount of modified nano-SiO2 added is 0.5%, and other process conditions are the same as those in embodiment 1.

Comparative Example 9:

In step 2, the amount of modified nano-SiO2 added is 4%, and other process conditions are the same as those in embodiment 1.

The relevant parameters of the monofilament in each embodiment and comparative example are given below:

The above data show that: 1. Compared with Example 1, the results of Comparative Example 1 show that the nanoparticle solution is too dilute, the degree of cross-linking is too large, and the elasticity becomes worse;

2. Comparative Example 2 Compared with Example 1, the results show that: the nanoparticle solution is too concentrated, the strength is poor, and the elasticity is poor;

3. Comparative Example 3 Compared with Example 1, the results show that the effect is worse when other coupling agents are used, and the strength and elasticity are poor;

4. Comparative Example 4 is compared with Example 1. The results show that the coupling agent KH550 is too little, and the strength and elasticity are poor;

5. Comparative Example 5 Compared with Example 1, the results show that: the amount of KH550 selected as the coupling agent is too large, the degree of cross-linking is large, and the elasticity is poor;

6. Comparative Example 6 Compared with Example 1, the results show that the reaction is insufficient, the grafting rate is not high, the agglomeration, and the strength and elasticity are poor;

7. Comparative Example 7 is compared with Example 1. The results show that: the reaction time is too long, the reaction has been completed, and the indicators have no obvious changes, which is the same as Example 1;

8. The results of comparative examples eight and nine show that when blended with copolymer polyamide, if the amount of modified nanoparticles added is too small, there will be no significant change in the improvement of mechanical properties, while if the amount added is too large, it will not have the effect of strengthening and toughening the polymer matrix, but will easily agglomerate to become stress concentration points, which will reduce the performance of the single fiber itself.

The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims (9)

1. A preparation method of high-resilience and anti-creep copolymerized nylon monofilament, is characterized in that, comprises steps: S10: providing inorganic nanoparticles, modifying the surface of the inorganic nanoparticles with a silane coupling agent to form modified nanoparticles, S20: After uniformly mixing the modified nanoparticles and the copolyamide, adding them to a twin-screw extruder for melt blending and extruding, the mass of the modified nanoparticles is 1-2, and the copolyamide The quality is divided into 98-99, S30: The melted extruded filaments are cooled by a coolant, the temperature of the coolant is less than or equal to 0°C, and then drawn and wound to form as-spun filaments; S40: Perform two stretches on the as-spun yarn, the first stretch is steam stretching, the stretching ratio is 3-4 times, the second stretching is hot air stretching, the stretching ratio is 1.1-1.5 times , and then carry out shaping treatment to form high resilience and anti-creep copolymerized nylon monofilament. 2. The method for preparing high-resilience and anti-creep copolymerized nylon monofilament according to claim 1, wherein said "surface modification of said inorganic nanoparticles" specifically comprises: S11: Fully mix the inorganic nanoparticles with an ethanol solution with a mass fraction of 75%, and the mass ratio of the inorganic nanoparticles to the ethanol solution is 5-10:100; S12: Add the silane coupling agent to the mixed solution, adjust the pH of the mixed solution with sodium hydroxide until the pH value is 7-9, the amount of the silane coupling agent added is 1-3 of the mass of the inorganic nanoparticles %; S13: heating the mixed solution to 75-85°C, keeping warm and stirring for 6-8 hours; S14: Centrifuge the incubated mixed solution to obtain modified nanoparticles. 3. The method for preparing high resilience and creep-resistance copolymerized nylon monofilament according to claim 2, further comprising drying and grinding the modified nanoparticles, and the particle size after grinding is 10-20 μm. 4. The method for preparing high-resilience and anti-creep copolymerized nylon monofilament according to claim 1, wherein the inorganic nanoparticles are spherical particles or rod-shaped or layered. 5. The method for preparing high resilience and creep-resistant creep copolymerized nylon monofilament according to claim 1, wherein the inorganic nanoparticles are inorganic nano-TiO ₂ , inorganic nano-SiO ₂ , nano-CaCO ₃ , nano-whiskers, One or more of nano-attapulgite, silicate, and vermiculite. 6. The method for preparing high-resilience and anti-creep copolymerized nylon monofilament according to claim 1, wherein the silane coupling agent is one of KH550, KH560, and KH570. 7. The method for preparing high-resilience and anti-creep copolymerized nylon monofilament according to claim 1, characterized in that the viscosity of the copolymerized polyamide is 2.4-3.2. 8. A method for preparing high-resilience and creep-resistant copolymerized nylon monofilaments according to any one of claims 1-7 to obtain copolymerized nylon monofilaments. 9. An application of the copolymerized nylon monofilament as claimed in claim 8.

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