Preparation method and application of nylon 66
Through in-situ polymerization technology, the antibacterial agent is evenly dispersed during the preparation of nylon 66, which solves the problem of uneven dispersion of antibacterial agents and the easy weakening of antibacterial properties in antibacterial nylon 66, and achieves better heat resistance and mechanical properties.
Patent Information
- Application Number
- CN202510313286.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-06-27
AI Technical Summary
The antibacterial nylon 66 with inorganic antibacterial agent added to the prior art has problems such as uneven dispersion of antibacterial agents, easy to weaken antibacterial properties over time, poor heat resistance and a great impact on the performance of nylon 66.
In-situ polymerization technology is used to prepare nylon 66 through salt formation reaction, pH adjustment, antibacterial agent mixing and polymerization reaction, ensuring that the antibacterial agent is dispersed more evenly during the polymerization process, thereby improving antibacterial and heat resistance.
The uniform dispersion of antibacterial agents was achieved, the heat resistance and durability of antibacterial nylon 66 were improved, and the mechanical properties of nylon 66 were improved compared with the control group.
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Figure CN120209294A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of polymer synthesis, and particularly relates to a preparation method and application of nylon 66. Background Art
[0002] Nylon is the variety with the largest output, the most varieties, and the widest uses among the five major engineering plastics. There are many types of nylon products. Common nylon 66 performs more excellently in terms of wear resistance and softness, and has received more and more attention. There are often a large number of pathogenic bacteria on the surface of nylon 66 products, and they can become the sources of bacterial pollution and disease transmission. In recent years, consumers have paid more and more attention to public health and health. Developing nylon 66 materials with antibacterial properties is of great significance.
[0003] By adding a certain amount of antibacterial agent to the nylon 66 matrix material, an antibacterial material with bactericidal and bacteriostatic effects can be obtained. There are three common types of antibacterial agents, namely natural antibacterial agents, organic antibacterial agents, and inorganic antibacterial agents. Inorganic antibacterial agents generally have the advantages of heat resistance, persistence, continuity, and environmental friendliness. Antibacterial nylon 66 added with inorganic antibacterial agents has gradually become a research hotspot. In the prior art, the preparation technologies of antibacterial nylon 66 added with inorganic antibacterial agents are mainly blending and grafting modification. These two preparation technologies have technical defects such as uneven dispersion of antibacterial agents, easy gradual weakening of antibacterial properties over time, poor heat resistance, and great influence on the properties of nylon 66 itself, which limit the development of antibacterial nylon 66.
[0004] Therefore, developing a preparation method and application of nylon 66 to solve the technical defects in the prior art that antibacterial nylon 66 added with inorganic antibacterial agents has uneven dispersion of antibacterial agents, easy gradual weakening of antibacterial properties over time, poor heat resistance, and great influence on the properties of nylon 66 itself has become an urgent problem to be solved by those skilled in the art. Summary of the Invention
[0005] Based on this, in view of the technical defects in the prior art that antibacterial nylon 66 added with inorganic antibacterial agents has uneven dispersion of antibacterial agents, easy gradual weakening of antibacterial properties over time, poor heat resistance, and great influence on the properties of nylon 66 itself, it is necessary to develop a preparation method and application of nylon 66.
[0006] This application provides a preparation method of nylon 66, and the preparation method includes:
[0007] Step 1: 1,6-hexanediamine, adipic acid and water undergo a salt-forming reaction to obtain a first product;
[0008] Step 2: Adjust the pH of the first product to obtain a second product;
[0009] Step 3: Mix the second product with an antibacterial agent to obtain a third product;
[0010] Step 4: Subject the third product to a polymerization reaction to obtain a fourth product;
[0011] Step 5: After the fourth product is discharged molten and then cooled, it is drawn into filaments and cut into pellets to obtain a nylon 66 product.
[0012] In one embodiment, in Step 4, the method of the polymerization reaction includes:
[0013] S1: Under a protective atmosphere, perform segmented pressurized heating and stirring to obtain a fourth intermediate product;
[0014] S2: After reducing the pressure to atmospheric pressure, evacuate, stir and heat to obtain a fourth product.
[0015] In one embodiment, in Step 4, S1 includes: maintaining the stirring speed at 60 - 100 rpm, heating and concentrating under a nitrogen protective atmosphere and at a pressure of 0.2 - 1 MPa, exhausting when the salt concentration in the reaction system reaches 70% - 90%, maintaining the pressure of the reaction system at 1.5 - 2.5 MPa, and heating at 240 - 270 °C to obtain a fourth intermediate product.
[0016] In one embodiment, in Step 4, S1 includes: maintaining the stirring speed at 80 - 100 rpm, heating and concentrating under a nitrogen protective atmosphere and at a pressure of 0.2 - 0.5 MPa, exhausting when the salt concentration in the reaction system reaches 80% - 90%, maintaining the pressure of the reaction system at 1.5 - 2 MPa, and heating at 250 - 260 °C to obtain a fourth intermediate product.
[0017] In one embodiment, S2 includes: maintaining the stirring speed at 50 - 80 rpm and the heating temperature at 260 - 290 °C, evacuating after reducing the pressure to atmospheric pressure, and maintaining the pressure of the reaction system at -0.8 - -0.2 MPa.
[0018] In one embodiment, S2 includes: maintaining the stirring speed at 65 - 80 rpm and the heating temperature at 270 - 280 °C, evacuating after reducing the pressure to atmospheric pressure, and maintaining the pressure of the reaction system at -0.6 - -0.4 MPa.
[0019] In one embodiment, in Step 1, in terms of mole parts, the molar ratio of 1,6 - hexanediamine to adipic acid is (1 - 1.1):1.
[0020] In one embodiment, in Step 1, in terms of mole parts, the molar ratio of 1,6 - hexanediamine to adipic acid is (1 - 1.05):1.
[0021] In one embodiment, in step two, the pH of the second product is 7.5 to 8.5;
[0022] and / or,
[0023] In step two, 1,6 - hexanediamine and / or adipic acid is used to adjust the pH.
[0024] In one embodiment, in step two, the pH of the second product is 8 to 8.5.
[0025] In one embodiment, in step three, the antibacterial agent is selected from any one or more of copper acetate, silver nitrate, and zinc acetate;
[0026] and / or,
[0027] In step three, the addition amount of the antibacterial agent is 300 - 1000 ppm of the total amount of 1,6 - hexanediamine and adipic acid.
[0028] In step three, the addition amount of the antibacterial agent is 400 - 800 ppm of the total amount of 1,6 - hexanediamine and adipic acid.
[0029] In one embodiment, in step five, the melt discharging is carried out in a nitrogen - protected atmosphere, and the reaction system pressure of the melt discharging is 0 to 0.1 MPa.
[0030] In one embodiment, in step five, the melt discharging is carried out in a nitrogen - protected atmosphere, and the reaction system pressure of the melt discharging is 0.01 to 0.1 MPa.
[0031] In one embodiment, in step five, the cooling temperature is 20 to 30 °C.
[0032] In one embodiment, in step five, the cooling temperature is 20 to 25 °C.
[0033] This application also provides an application of the preparation method described in any one of the above in the preparation of antibacterial nylon products.
[0034] In summary, the present application provides a method for preparing nylon 66, including a salt formation reaction, pH adjustment, antibacterial agent mixing, polymerization reaction, and melt discharging. The present application also provides an application of the above preparation method in the preparation of antibacterial nylon products. In the technical solution provided by the embodiments of the present application, the method for preparing nylon 66 uses an in-situ polymerization technique, which can make the antibacterial agent more uniformly dispersed and have better heat resistance. The obtained nylon 66 still has good antibacterial properties after 16 hours of water washing treatment. Compared with the control group, the mechanical properties of nylon 66, such as tensile strength, flexural strength, impact strength, etc., are all better than those of the control group; it solves the technical defects in the prior art that the antibacterial nylon 66 added with an inorganic antibacterial agent has uneven dispersion of the antibacterial agent, the antibacterial performance is prone to gradually weaken over time, poor heat resistance, and a greater impact on the performance of nylon 66 itself. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.
[0036] Figure 1 It is a schematic flow chart of a method for preparing nylon 66 in the technical solution provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0037] The embodiments of the present application provide a method for preparing nylon 66 and its application, which are used to solve the technical defects in the prior art that the antibacterial nylon 66 added with an inorganic antibacterial agent has uneven dispersion of the antibacterial agent, the antibacterial performance is prone to gradually weaken over time, poor heat resistance, and a greater impact on the performance of nylon 66 itself.
[0038] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will make a detailed description of the specific embodiments of the present application with reference to the drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.
[0039] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.
[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.
[0041] In the present application, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0042] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0043] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.
[0044] The following will be combined with Figure 1 the schematic process diagram of the preparation method to prepare a nylon 66 product by using a nylon 66 preparation method provided by the present application.
[0045] Example 1
[0046] 6 mol of 1,6-hexanediamine, 6 mol of adipic acid and 1574 ml of water were added to a salting kettle and mixed evenly. They were mixed evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution, wherein the weight of the salt in the salt solution was 0.9 kg. When the concentration of the nylon salt solution was 10 wt.%, 1,6-hexanediamine or adipic acid was used to adjust the pH value of the salt solution to 7.96. An antibacterial agent copper acetate was added to the nylon salt solution, and the addition amount of copper acetate was 300 ppm of the total mass of 1,6-hexanediamine and adipic acid.
[0047] The nylon salt solution was transferred to a polymerization kettle and heated under a nitrogen protection atmosphere. When the pressure in the reaction system rose to 0.3 MPa, exhaust gas was discharged, and it was heated and concentrated under pressure for 0.5 h. When the pressure maintaining ended, the nylon salt solution was concentrated to 80%. Then the temperature was raised to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas was discharged, and the pressure was maintained. The temperature of the reaction system was maintained at 242.0 °C and heated for 1 h. The pressure in the reaction system was reduced uniformly to normal pressure, and then vacuum was pumped to maintain at -0.04 MPa. The vacuum pumping time was 22 min, the temperature of the reaction system was maintained at 279.0 °C, and the rotation speed of the stirring paddle was 75 rpm. At this time, a nylon melt polymerization product was obtained.
[0048] N2 was introduced to make the pressure in the reaction system 0.03 MPa, and it was discharged by melting. After cooling in a water tank, it was drawn into filaments and cut into pellets, wherein the cooling water temperature of the water tank was 25 °C.
[0049] Example 2
[0050] 6 mol of 1,6 - hexanediamine, 6 mol of adipic acid and 1574 ml of water were added to a salting kettle and mixed evenly. They were mixed evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution was 0.9 kg; when the concentration of the nylon salt solution was 10 wt.%, 1,6 - hexanediamine or adipic acid was used to adjust the pH value of the salt solution to 7.96. An antibacterial agent, copper acetate, was added to the nylon salt solution, and the addition amount of copper acetate was 700 ppm of the total mass of 1,6 - hexanediamine and adipic acid.
[0051] The nylon salt solution was transferred to a polymerization kettle and heated under a nitrogen - protected atmosphere. When the pressure in the reaction system rose to 0.3 MPa, exhaust gas was discharged, and it was heated under constant pressure for concentration for 0.7 h. When the constant - pressure ended, the nylon salt solution was concentrated to 80%. Then the temperature was raised to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas was discharged, and it was kept under pressure. The temperature of the reaction system was maintained at 240.7 °C and heated for 2 h. The pressure was reduced uniformly to make the pressure in the reaction system drop to atmospheric pressure, and then vacuum was pumped to maintain at - 0.04 MPa. The vacuum - pumping time was 22 min, the temperature of the reaction system was maintained at 279.3 °C, and the rotation speed of the stirring paddle was 77 rpm. At this time, a nylon melt polymerization product was obtained.
[0052] Nitrogen was introduced to make the pressure of the reaction system 0.02 MPa, and it was discharged in a molten state. After cooling in a water tank, it was drawn into filaments and cut into pellets. Among them, the cooling water temperature of the water tank was 25 °C.
[0053] Example 3
[0054] 6 mol of 1,6 - hexanediamine, 6 mol of adipic acid and 1574 ml of water were added to a salting kettle and mixed evenly. They were mixed evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution was 0.9 kg. When the concentration of the nylon salt solution was 10 wt.%, 1,6 - hexanediamine or adipic acid was used to adjust the pH value of the salt solution to 7.94. An antibacterial agent, copper acetate, was added to the nylon salt solution, and the addition amount of copper acetate was 1000 ppm of the total mass of 1,6 - hexanediamine and adipic acid.
[0055] The nylon salt solution was transferred to a polymerization kettle and heated under a nitrogen - protected atmosphere. When the pressure in the reaction system rose to 0.3 MPa, exhaust gas was discharged, and it was heated under constant pressure for concentration for 1 h. When the constant - pressure ended, the nylon salt solution was concentrated to 80%. Then the temperature was raised to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas was discharged, and it was kept under pressure. The temperature of the reaction system was maintained at 244.2 °C and heated for 0.5 h. The pressure was reduced uniformly to make the pressure in the reaction system drop to atmospheric pressure, and then vacuum was pumped to maintain at - 0.04 MPa. The vacuum - pumping time was 25 min, the temperature of the reaction system was maintained at 279.2 °C, and the rotation speed of the stirring paddle was 76 rpm. At this time, a nylon melt polymerization product was obtained.
[0056] Introduce N2 to make the pressure of the reaction system 0.03 MPa, discharge the melt, cool it by passing through a water tank and then draw it into filaments and cut into pellets. Among them, the water temperature of the water tank is 25 °C.
[0057] Example 4
[0058] Add 6 mol of 1,6-hexanediamine, 6 mol of adipic acid and 1574 ml of water to the salifying kettle and mix evenly. Mix evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution is 0.9 kg. When the concentration of the nylon salt solution is 10 wt.%, use 1,6-hexanediamine or adipic acid to adjust the pH value of the salt solution to 8.00. Add antibacterial agent silver nitrate to the nylon salt solution, and the addition amount of silver nitrate is 300 ppm of the total mass of 1,6-hexanediamine and adipic acid.
[0059] Transfer the nylon salt solution to the polymerization kettle and heat it under a N2 protective atmosphere. When the pressure in the reaction system rises to 0.3 MPa, exhaust gas, maintain the pressure and heat to concentrate for 0.9 h. When the pressure maintaining ends, the nylon salt solution is concentrated to 80%. Then raise the temperature to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas, maintain the pressure and maintain the temperature of the reaction system at 241.2 °C and heat for 2 h. Slowly reduce the pressure to make the pressure in the reaction system drop to atmospheric pressure, and then evacuate to maintain at -0.04 MPa. The evacuation time is 20 min, maintain the temperature of the reaction system at 277.5 °C, and the rotation speed of the stirring paddle is 74 rpm. At this time, a nylon melt polymerization product is obtained.
[0060] Introduce N2 to make the pressure of the reaction system 0.04 MPa, discharge the melt, cool it by passing through a water tank and then draw it into filaments and cut into pellets. Among them, the cooling water temperature of the water tank is 25 °C.
[0061] Example 5
[0062] Add 6 mol of 1,6-hexanediamine, 6 mol of adipic acid and 1574 mol of water to the salifying kettle and mix evenly. Mix evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution is 0.9 kg. When the concentration of the nylon salt solution is 10 wt.%, use 1,6-hexanediamine or adipic acid to adjust the pH value of the salt solution to 7.99. Add antibacterial agent silver nitrate to the nylon salt solution, and the addition amount of silver nitrate is 700 ppm of the total mass of 1,6-hexanediamine and adipic acid.
[0063] Transfer the nylon salt solution to a polymerization kettle, heat it under a nitrogen protection atmosphere. When the pressure in the reaction system rises to 0.3 MPa, exhaust the gas, maintain the pressure and heat to concentrate for 0.6 h. When the pressure maintaining ends, the nylon salt solution is concentrated to 80%. Then raise the temperature to make the pressure in the reaction system rise to 2.0 MPa, exhaust the gas, maintain the pressure, and maintain the temperature of the reaction system at 239.7 °C and heat for 1.3 h. Slowly reduce the pressure to make the pressure in the reaction system drop to atmospheric pressure, then evacuate and maintain at -0.04 MPa. The evacuation time is 17 min, maintain the temperature of the reaction system at 279.2 °C, and the rotation speed of the stirring paddle is 75 rpm. At this time, the nylon melt polymerization product is obtained.
[0064] Introduce N2 to make the pressure of the reaction system 0.05 MPa, discharge the melt, cool it through a water tank and then draw and pelletize. Among them, the cooling water temperature of the water tank is 25 °C.
[0065] Example 6
[0066] Add 6 mol of 1,6-hexanediamine, 6 mol of adipic acid and 1574 ml of water to a salt-forming kettle and mix evenly. Mix evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution is 0.9 kg. When the concentration of the nylon salt solution is 10 wt.%, use 1,6-hexanediamine or adipic acid to adjust the pH value of the salt solution to 8.03. Add silver nitrate as an antibacterial agent to the nylon salt solution. Among them, the addition amount of silver nitrate is 1000 ppm of the total mass of 1,6-hexanediamine and adipic acid.
[0067] Transfer the nylon salt solution to a polymerization kettle, heat it under a nitrogen protection atmosphere. When the pressure in the reaction system rises to 0.3 MPa, exhaust the gas, maintain the pressure and heat to concentrate for 0.5 h. When the pressure maintaining ends, the nylon salt solution is concentrated to 80%. Then raise the temperature to make the pressure in the reaction system rise to 2.0 MPa, exhaust the gas, maintain the pressure, and maintain the temperature of the reaction system at 244.8 °C and heat for 1.5 h. Slowly reduce the pressure to make the pressure in the reaction system drop to atmospheric pressure, then evacuate and maintain at -0.04 MPa. The evacuation time is 18 min, maintain the temperature of the reaction system at 276.3 °C, and the rotation speed of the stirring paddle is 75 rpm. At this time, the nylon melt polymerization product is obtained.
[0068] Introduce N2 to make the pressure of the reaction system 0.04 MPa, discharge the melt, cool it through a water tank and then draw and pelletize. Among them, the cooling water temperature of the water tank is 25 °C.
[0069] Example 7
[0070] 6 mol of 1,6 - hexanediamine, 6 mol of adipic acid and 1574 ml of water were added to a salifying kettle and mixed evenly. They were mixed evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution was 0.9 kg. When the concentration of the nylon salt solution was 10 wt.%, 1,6 - hexanediamine or adipic acid was used to adjust the pH value of the salt solution to 8.02. Zinc acetate as an antibacterial agent was added to the nylon salt solution, and the addition amount of zinc acetate was 300 ppm of the total mass of 1,6 - hexanediamine and adipic acid.
[0071] The nylon salt solution was transferred to a polymerization kettle and heated under a N₂ - protected atmosphere. When the pressure in the reaction system rose to 0.3 MPa, exhaust gas was discharged, and it was heated and concentrated under pressure for 0.5 h. When the pressure - maintaining ended, the nylon salt solution was concentrated to 80%. Then the temperature was raised to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas was discharged, and pressure was maintained. The temperature of the reaction system was maintained at 246.7 °C and heated for 2 h. The pressure in the reaction system was reduced uniformly to atmospheric pressure, and then vacuum was pumped to maintain at - 0.04 MPa. The vacuum - pumping time was 23 min, the temperature of the reaction system was maintained at 274.9 °C, and the rotation speed of the stirring paddle was 74 rpm. At this time, a nylon melt polymerization product was obtained.
[0072] N₂ was introduced to make the pressure in the reaction system 0.05 MPa, and it was discharged in a molten state. After cooling in a water tank, it was drawn into filaments and cut into pellets. Among them, the cooling water temperature of the water tank was 25 °C.
[0073] Example 8
[0074] 6 mol of 1,6 - hexanediamine, 6 mol of adipic acid and 1574 ml of water were added to a salifying kettle and mixed evenly. They were mixed evenly under the conditions of 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution was 0.9 kg. When the concentration of the nylon salt solution was 10 wt.%, 1,6 - hexanediamine or adipic acid was used to adjust the pH value of the salt solution to 7.98. Zinc acetate as an antibacterial agent was added to the nylon salt solution, and the addition amount of zinc acetate was 700 ppm of the total mass of 1,6 - hexanediamine and adipic acid.
[0075] The nylon salt solution was transferred to a polymerization kettle and heated under a N₂ - protected atmosphere. When the pressure in the reaction system rose to 0.3 MPa, exhaust gas was discharged, and it was heated and concentrated under pressure for 0.9 h. When the pressure - maintaining ended, the nylon salt solution was concentrated to 80%. Then the temperature was raised to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas was discharged, and pressure was maintained. The temperature of the reaction system was maintained at 247.2 °C and heated for 1.2 h. The pressure in the reaction system was reduced uniformly to atmospheric pressure, and then vacuum was pumped to maintain at - 0.04 MPa. The vacuum - pumping time was 24 min, the temperature of the reaction system was maintained at 280.6 °C, and the rotation speed of the stirring paddle was 76 rpm. At this time, a nylon melt polymerization product was obtained.
[0076] Introduce N2 to make the pressure of the reaction system 0.06 MPa, melt and discharge the material, and draw and pelletize after cooling in a water tank. Among them, the cooling water temperature of the water tank is 25 °C.
[0077] Example 9
[0078] Add 6 mol of 1,6-hexanediamine, 6 mol of adipic acid and 1574 ml of water into the salifying kettle and mix evenly. Mix evenly at 50 °C and 150 rpm to obtain a 30% nylon salt solution. Among them, the weight of the salt in the salt solution is 0.9 kg. When the concentration of the nylon salt solution is 10 wt.%, use 1,6-hexanediamine or adipic acid to adjust the pH value of the salt solution to 8.01. Add zinc acetate as an antibacterial agent to the nylon salt solution. Among them, the addition amount of zinc acetate is 1000 ppm of the total mass of 1,6-hexanediamine and adipic acid.
[0079] Transfer the nylon salt solution to the polymerization kettle and heat it under a N2 protective atmosphere. When the pressure in the reaction system rises to 0.3 MPa, exhaust gas, maintain the pressure and heat and concentrate for 1 h. When the pressure maintaining ends, the nylon salt solution is concentrated to 80%. Then raise the temperature to make the pressure in the reaction system rise to 2.0 MPa, exhaust gas, maintain the pressure, and maintain the temperature of the reaction system at 248.4 °C and heat for 0.5 h. Slowly reduce the pressure to make the pressure in the reaction system drop to atmospheric pressure, and then evacuate and maintain at -0.04 MPa. The evacuation time is 25 min, maintain the temperature of the reaction system at 279.6 °C, and the rotation speed of the stirring paddle is 76 rpm. At this time, a nylon melt polymerization product is obtained.
[0080] Introduce N2 to make the pressure of the reaction system 0.05 MPa, melt and discharge the material, and draw and pelletize after cooling in a water tank. Among them, the cooling water temperature of the water tank is 25 °C.
[0081] Comparative Example 1
[0082] (1) Mix 1,6-hexanediamine, adipic acid and water evenly at 50 °C and 150 rpm to obtain a 30% nylon salt solution. The weight of the salt in the salt solution is 0.9 kg; the molar ratio of 1,6-hexanediamine to adipic acid is (1 - 1.1):1, and the pH value when the concentration of the nylon salt solution is 10 wt.% is 7.99. The percentage is the mass percentage of the nylon salt solution.
[0083] (2) Under the protection of N2, heat the nylon salt solution. When the pressure in the reaction system rises to 0.3 MPa, exhaust the gas, maintain the pressure. When the pressure maintaining ends, the nylon salt solution is concentrated to 80%. Then raise the temperature to make the pressure in the reaction system rise to 2.0 MPa, exhaust the gas, maintain the pressure. When the pressure maintaining ends, the temperature of the reaction system is 240.0 °C. Then gradually reduce the pressure evenly to make the pressure in the reaction system drop to atmospheric pressure. After that, evacuate and maintain at -0.04 MPa. The evacuation time is 20 min. After the evacuation is completed, the temperature of the reaction system is 279.0 °C, and the rotation speed of the stirring paddle is 75 rpm. At this time, nylon melt is obtained.
[0084] (3) Introduce N2 to make the pressure of the reaction system 0.03 MPa, discharge the melt, and draw and pelletize after cooling through a water bath. The water temperature of the water bath is 25 °C.
[0085] Comparative Example 2
[0086] The preparation steps of the antibacterial nylon in this comparative example are as follows:
[0087] 1) Prepare nylon 66 pellets according to the preparation method of Comparative Example 1;
[0088] 2) Spray 0.5% by mass of the organosilicon quaternary ammonium salt antibacterial agent based on the nylon 66 obtained in step 1) and feed it into a screw melt extruder for extrusion. Draw and pelletize after cooling through a water bath. The water temperature of the water bath is 25 °C.
[0089] Comparative Example 3
[0090] The preparation method of the antibacterial nylon in this comparative example is the same as that of Comparative Example 1, except that 0.1 wt% of chitosan is added as an antibacterial agent in step (1).
[0091] Example 10
[0092] This example is a specific example for measuring the performance of the products prepared in Examples 1 - 9 and the products prepared in Comparative Examples 1 - 3.
[0093] 10.1 Relative viscosity
[0094] In this example, the method for measuring the relative viscosity refers to GB 12006.1.
[0095] Please refer to Table 1 for the measured results.
[0096] Table 1
[0097]
[0098]
[0099] Among them, the higher the measurement result of the relative viscosity, the better the mechanical properties of the nylon and the higher the thermal stability. Thus, it can be concluded from Table 1 that the antibacterial nylon prepared by the technical solution provided in the embodiments of the present application has better mechanical properties and thermal stability.
[0100] 10.2 Mechanical Properties
[0101] In this embodiment, the tensile strength, flexural strength, and impact strength of each sample were measured. Among them, the measurement method of the tensile strength refers to GB / T 1040.2-2022, the measurement method of the flexural strength refers to GB / T 9341-2008, and the measurement method of the impact strength refers to GB / T 1843-2008.
[0102] Please refer to Table 2 for the measurement results.
[0103] Table 2
[0104]
[0105]
[0106] It can be concluded from Table 2 that the antibacterial nylon prepared by the technical solution provided in the embodiments of the present application has better mechanical properties.
[0107] 10.3 Antibacterial Properties
[0108] In this embodiment, the antibacterial properties of each sample were measured. Among them, the test strain was Escherichia coli ATCC 8739, and the test method referred to the antibacterial performance test in GB / T 31402-2023.
[0109] Please refer to Table 3 for the measurement results.
[0110] Table 3
[0111]
[0112]
[0113] It can be concluded from Table 3 that the antibacterial nylon prepared by the technical solution provided in the embodiments of the present application has better antibacterial properties.
[0114] 10.4 Antibacterial Wash Durability
[0115] In this embodiment, the antibacterial wash durability of each sample was measured. Among them, the test strain was Escherichia coli AS1.90, and the test method referred to the antibacterial durability test in JC / T 939-2004.
[0116] Please refer to Table 4 for the measurement results.
[0117] Table 4
[0118]
[0119]
[0120] It can be seen from Table 4 that the antibacterial nylon prepared by the technical solution provided in the embodiments of the present application has better antibacterial and washing durability performance.
[0121] It can be concluded from the above embodiments that a method for preparing nylon 66 provided by the present application has the following advantages:
[0122] First, compared with the blending technology used in the preparation of antibacterial nylon 66 with inorganic antibacterial agents in the prior art, the technical solution of the present application uses an in-situ polymerization technology, which makes the dispersion of the inorganic antibacterial agent more uniform, and the antibacterial performance is not easily reduced gradually over time.
[0123] Second, the antibacterial nylon 66 product prepared by the technical solution of the present application using the in-situ polymerization technology has good heat resistance, little influence on the properties of nylon itself, high safety, and low cost.
[0124] Third, the technical solution of the present invention uses water as the solvent and does not add any catalysts except the antibacterial agent, which is environmentally friendly and easy to implement.
[0125] A method for preparing nylon 66 provided by the embodiments of the present application has the advantages of simple preparation, no pollution, and excellent antibacterial performance, and can be widely used in the preparation of antibacterial nylon products.
[0126] In summary, the present application provides a method for preparing nylon 66, including: salt formation reaction, pH adjustment, antibacterial agent mixing, polymerization reaction, and melt discharging. The present application also provides an application of the above preparation method in the preparation of antibacterial nylon products. In the technical solution provided by the embodiments of the present application, the method for preparing nylon 66 uses an in-situ polymerization technology, which can make the antibacterial agent disperse more uniformly and have better heat resistance. The nylon 66 prepared still has good antibacterial performance after 16 hours of washing treatment. Compared with the control group, the mechanical properties of nylon 66, such as tensile strength, flexural strength, impact strength, etc., are all better than those of the control group; it solves the technical defects in the prior art that the antibacterial nylon 66 with inorganic antibacterial agents has uneven dispersion of antibacterial agents, easy gradual weakening of antibacterial performance over time, poor heat resistance, and great influence on the properties of nylon 66 itself.
[0127] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification. At the same time, other embodiments can be derived from the above-described embodiments, so that structural and logical substitutions and changes can be made without departing from the scope of the present disclosure.
[0128] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.
Claims
1. A method for preparing nylon 66, characterized in that: The preparation method comprises: Step 1: 1,6-hexanediamine, adipic acid and water react to form a salt to obtain a first product; Step 2: adjusting the pH of the first product to obtain a second product; Step 3, mixing the second product with an antimicrobial agent to obtain a third product; Step 4, the third product undergoes a polymerization reaction to obtain a fourth product; Step 5: After the fourth product is melted and discharged, it is cooled, drawn and pelletized to obtain a nylon 66 product.
2. The preparation method according to claim 1, characterized in that: In step 4, the polymerization method includes: S1, under protective atmosphere, heating under staged pressure, stirring to obtain a fourth intermediate product; S2, reduce the pressure to normal pressure and then evacuate, stir and heat to obtain the fourth product.
3. The preparation method according to claim 2, characterized in that: In step 4, S1 includes: maintaining the stirring speed at 60-100 rpm, heating and concentrating for 0.5-1h under a nitrogen protective atmosphere and a pressure of 0.2-1MPa, exhausting when the salt concentration in the reaction system is 70%-90%, maintaining the pressure of the reaction system at 1.5-2.5MPa, and heating at 240-270°C for 0.5-2h to obtain a fourth intermediate product.
4. The preparation method according to claim 2 or 3, characterized in that: The step S2 includes: maintaining a stirring speed of 65 to 80 rpm and a heating temperature of 260 to 290° C., reducing the pressure to normal pressure and then evacuating for 10 to 40 minutes, and maintaining the pressure of the reaction system at -0.8 to -0.2 MPa.
5. The preparation method according to claim 1, characterized in that: In step 1, the molar ratio of 1,6-hexanediamine to adipic acid is (1-1.1):1 in molar parts.
6. The preparation method according to claim 1, characterized in that: In step 2, the pH of the second product is 7.5 to 8.5; and / or, In step 2, 1,6-hexamethylenediamine and / or adipic acid are used to adjust the pH.
7. The preparation method according to claim 1, characterized in that: In step 3, the antibacterial agent is selected from any one or more of copper acetate, silver nitrate and zinc acetate; and / or, In step three, the amount of the antibacterial agent added is 300 to 1000 ppm of the total amount of 1,6-hexanediamine and adipic acid.
8. The preparation method according to claim 1, characterized in that: In step five, the molten material is discharged in a nitrogen protective atmosphere, and the pressure of the reaction system of the molten material is 0-0.1 MPa.
9. The preparation method according to claim 1 or 8, characterized in that: In step 5, the cooling temperature is 20-30°C.
10. Use of the preparation method according to any one of claims 1 to 9 in the preparation of antibacterial nylon products.