Antibacterial nylon 6 elastomer and preparation method thereof

Abstract

The invention relates to the technical field of antibacterial nylon, and discloses an antibacterial nylon 6 elastomer and a preparation method thereof, the elastomer comprises the following raw materials: 10-100 parts of caprolactam, 0.1-0.5 part of a catalyst, 5-10 parts of an antibacterial agent, 10-100 parts of polyether amine, 10-100 parts of binary acid and the balance of water, and the antibacterial agent comprises a surface hydroxyl modified inorganic antibacterial agent; according to the elastomer, the elastic property and the softness of the nylon elastomer are remarkably improved by adjusting the ratio of the soft segment polyether amine to the nylon hard segment; a hydroxyl inorganic antibacterial agent dispersion liquid is further added into the elastomer, the antibacterial agent cannot agglomerate when participating in nylon copolymerization, and in addition, agglomeration of the antibacterial agent in the nylon elastomer is further avoided by adjusting the adding opportunity of the antibacterial agent in the copolymerization stage.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial nylon, and in particular to an antibacterial nylon 6 elastomer and a preparation method thereof. Background Art

[0002] Nylon materials have excellent wear resistance and mechanical properties and are widely used in fields such as clothing, decoration, and medical devices. In these application fields, nylon elastomers have received more attention due to their better elasticity, softness, and other properties. Moreover, the properties of nylon elastomers can be accurately regulated by adjusting the ratio of hard and soft segments, and more abundant functions can be imparted by introducing other functional monomers or active substances. For example, in the patent with publication number CN117603449A, nylon is used as the hard segment to prepare nylon elastomer materials with polyetheramine. In this scheme, the raw materials mostly use long carbon chain monomers, which are expensive, and the polymerization preparation process is complex, requiring processes such as salt formation and dehydration condensation. The polymerization takes a long time and has a high cost. Another example is the patent with publication number CN114196193B, which uses lactam and hydroxyl polyether / polyester polyols to prepare nylon through anionic polymerization. However, this method has high requirements for the water content of the raw materials, a relatively low relative viscosity, and limited production.

[0003] In daily life, when nylon elastomer materials are used in fields such as sports clothing, shoe soles, and medical catheters, they are extremely prone to contamination by various bacteria and microorganisms, which poses a hazard to human health. With the improvement of living standards, people increasingly attach importance to the development of functional materials such as health and antibacterial protection. Currently, common antibacterial nylon elastomer materials are prepared by blending antibacterial components during the processing, but the blending method has problems such as poor compatibility and easy precipitation during long-term use. In addition, in the patent with publication number CN116574251A, an organic antibacterial agent is selected as a copolymerization component for modification, but it requires steps such as prior reaction preparation, salt formation, and polycondensation, and the process is relatively complex. Moreover, the organic antibacterial agent has poor heat resistance and is extremely prone to thermal decomposition during the polymerization process, thus losing its function. Inorganic antibacterial agents also have excellent antibacterial properties, but due to their poor dispersibility during copolymerization, there are still significant application obstacles in applying inorganic antibacterial agents to copolymer synthesis. Summary of the Invention

[0004] Aiming at the problem of poor dispersibility of inorganic antibacterial agents in copolymer synthesis in the prior art, the present invention provides an antibacterial nylon 6 elastomer and a preparation method thereof. By adding a polyetheramine soft segment to nylon, the nylon elastomer has excellent elastic properties and softness. In addition, the present invention also uses an antibacterial agent dispersion liquid prepared by modifying an inorganic antibacterial agent with surface hydroxyl groups. Using the inorganic antibacterial agent modified with surface hydroxyl groups can significantly reduce the agglomeration effect of the inorganic antibacterial agent during copolymerization and improve the dispersibility of the inorganic antibacterial agent in the copolyester.

[0005] The specific technical solution of the present invention is as follows: An antibacterial nylon 6 elastomer, the raw materials of which include 10-100 parts of caprolactam, 0.1-0.5 parts of catalyst, 5-10 parts of antibacterial agent, 10-100 parts of polyetheramine, 10-100 parts of dibasic acid and the balance of water, and the antibacterial agent includes an inorganic antibacterial agent modified with surface hydroxyl groups.

[0006] The present invention provides an antibacterial nylon 6 elastomer. A polyetheramine soft segment is added to the raw materials of the nylon elastomer. By regulating the nylon hard segment and the polyetheramine soft segment, the nylon elastomer can have excellent mechanical properties. In order to endow the nylon elastomer with antibacterial properties, an antibacterial agent dispersion is also added in the present invention. The nylon elastomer of the present invention is prepared by a copolymerization synthesis method. Therefore, in order to ensure that the antibacterial agent is not affected by the high temperature of the copolymerization synthesis, an inorganic antibacterial agent is selected as the antibacterial agent of the present invention. Although the inorganic antibacterial agent is not affected by high temperature, it is prone to agglomeration during copolymerization. Therefore, in order to improve the dispersibility of the inorganic dispersant during copolymerization, the dispersant is surface-modified and then the surface-modified inorganic antibacterial agent and water are made into a dispersion. By adding the dispersion to the nylon copolymerization system, participating in the nylon copolymerization in the form of an inorganic antibacterial agent dispersion can significantly improve the dispersibility of the inorganic antibacterial agent in nylon.

[0007] In addition, the present invention finds that when the inorganic antibacterial agent is surface-modified with functional groups such as carboxyl and amino groups, the modified inorganic antibacterial agent will agglomerate after being added to the copolymerization system, and the dispersibility of the inorganic antibacterial agent will be significantly reduced. Only when hydroxyl groups are grafted on the surface of the inorganic surface antibacterial agent, the inorganic antibacterial agent will not have agglomeration problems.

[0008] Preferably, the inorganic antibacterial agent modified with surface hydroxyl groups is zinc oxide modified with surface hydroxyl groups.

[0009] Preferably, the particle size of the inorganic antibacterial agent modified with surface hydroxyl groups is 20-50 nm.

[0010] The inorganic antibacterial agent modified with surface hydroxyl groups of the present invention uses zinc oxide modified with surface hydroxyl groups, and the zinc oxide modified with surface hydroxyl groups is prepared by the method disclosed in the invention patent CN118812918A. The zinc oxide particles can form strong hydrogen bond interactions with nylon molecules, avoiding precipitation during use. Zinc oxide has good biocompatibility and excellent thermal stability and is not affected by the high temperature during polymerization and processing.

[0011] Preferably, the antibacterial agent further includes water.

[0012] Preferably, the solid content of the antibacterial agent is 20-50%.

[0013] Preferably, the catalyst is one or more of phosphorous acid, zinc phosphite, sodium phosphite, potassium phosphite, boric acid and phosphoric acid.

[0014] Preferably, the dibasic acid is one or more of succinic acid, adipic acid, and sebacic acid.

[0015] Preferably, the molecular weight of the polyetheramine is 700 - 2000.

[0016] A preparation method of the above-mentioned antibacterial nylon 6 elastomer includes the following steps: adding caprolactam, water, and a catalyst into a reaction kettle for prepolymerization reaction. After the prepolymerization reaction ends, an antibacterial agent is added and stirred evenly to form an inorganic prepolymer, and then the polyetheramine and the dibasic acid are added into the inorganic prepolymer for polycondensation reaction to form the antibacterial nylon 6 elastomer.

[0017] The present invention also provides the preparation method of the above-mentioned antibacterial nylon 6 elastomer. In this method, a hydroxy inorganic antibacterial agent dispersion liquid is added after the ring-opening hydrolysis of caprolactam. By adjusting the addition timing of the hydroxy inorganic antibacterial agent dispersion liquid, it is possible to avoid the problem that the hydroxy inorganic antibacterial agent dispersion liquid contacts caprolactam for a long time, resulting in an imbalance in the surface charge of the inorganic antibacterial agent and causing agglomeration of the inorganic antibacterial agent, and ensure the dispersibility of the inorganic antibacterial agent.

[0018] In addition, the dibasic acid and the polyetheramine in this method are added after the antibacterial agent is mixed evenly with the prepolymer. Acidic substances such as dibasic acid can also cause an imbalance in the surface charge of the antibacterial agent, resulting in agglomeration of the antibacterial agent. Therefore, the addition timing of the antibacterial agent to ensure that the antibacterial agent does not agglomerate is extremely important.

[0019] Preferably, according to the preparation method described in claim 5, the conditions of the polycondensation reaction include: the temperature is 240 - 260 °C, the pressure is 300 - 600 kPa, and the reaction time is 1 - 5 h.

[0020] Preferably, the conditions of the polycondensation reaction include: reacting at 240 - 260 °C under normal pressure for 1 - 2 h, and then evacuating to - 20 - - 50 kPa and continuing the reaction for 2 - 3 h.

[0021] Preferably, after the prepolymerization reaction ends, it is depressurized to normal pressure.

[0022] Compared with the prior art, the present application has the following technical effects: The nylon elastomer of the present invention is synthesized by copolymerization of caprolactam, and polyetheramine is used in the raw materials. By adjusting the ratio of the soft segment polyetheramine to the nylon hard segment, the elastic properties and softness of the nylon elastomer are improved. A hydroxy inorganic antibacterial agent dispersion liquid is also added to the nylon elastomer of the present invention. The reason for choosing the hydroxy inorganic antibacterial agent dispersion liquid is that compared with inorganic antibacterial agents surface-modified with other functional groups, the hydroxy inorganic antibacterial agent will not agglomerate when participating in nylon copolymerization.

[0023] The method of the nylon elastomer provided by the present invention adjusts the addition timing of the hydroxyl inorganic antibacterial agent dispersion liquid. The present invention discovers that when the ring-opening hydrolysis of caprolactam and the addition of dibasic acid occur and the antibacterial agent is added, the antibacterial agent will agglomerate. Therefore, the present invention avoids the coincidence of the addition timing of the antibacterial agent with the ring-opening hydrolysis of caprolactam and the addition of dibasic acid, ensuring that the antibacterial agent does not agglomerate and improving the dispersibility of the antibacterial agent. Detailed implementation manners

[0024] The present invention will be further described below in conjunction with embodiments.

[0025] Embodiment 1: A preparation method of an antibacterial nylon 6 elastomer includes the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid are added into a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle is heated to 250 °C, and a ring-opening prepolymerization reaction is carried out for 2 h under the condition that the pressure is maintained at 600 kPa. After the prepolymerization reaction ends, the polymerization kettle is quickly depressurized to normal pressure, and then 0.2 kg of an antibacterial agent (a dispersion liquid with a solid content of 50% made of zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) is added into the polymerization kettle and rapidly stirred for 15 min; then 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid are added into the polymerization kettle and stirred at 250 °C under normal pressure for 1.5 h, and then the reaction kettle is evacuated to -50 kPa and the reaction continues for 2 h to produce the antibacterial nylon 6 elastomer.

[0026] Embodiment 2: A preparation method of an antibacterial nylon 6 elastomer includes the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid are added into a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle is heated to 250 °C, and a ring-opening prepolymerization reaction is carried out for 2 h under the condition that the pressure is maintained at 600 kPa. After the prepolymerization reaction ends, the polymerization kettle is quickly depressurized to normal pressure, and then 0.2 kg of an antibacterial agent (a dispersion liquid with a solid content of 50% made of zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) is added into the polymerization kettle and rapidly stirred for 15 min; then 5 kg of polyetheramine (with a molecular weight of 700) and 1.04 kg of adipic acid are added into the polymerization kettle and stirred at 250 °C under normal pressure for 1.5 h, and then the reaction kettle is evacuated to -50 kPa and the reaction continues for 2 h to produce the antibacterial nylon 6 elastomer.

[0027] Embodiment 3: A preparation method of an antibacterial nylon 6 elastomer includes the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and a ring-opening prepolymerization reaction was carried out for 2 h under the condition that the pressure was maintained at 600 kPa. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 10 kg of polyetheramine (with a molecular weight of 700) and 2.09 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0028] Example 4: A method for preparing an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and a ring-opening prepolymerization reaction was carried out for 2 h under the condition that the pressure was maintained at 600 kPa. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 10 kg of polyetheramine (with a molecular weight of 900) and 0.49 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0029] Example 5: A method for preparing an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and a ring-opening prepolymerization reaction was carried out for 2 h under the condition that the pressure was maintained at 600 kPa. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 3 kg of polyetheramine (with a molecular weight of 1500) and 0.29 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0030] Example 6: A method for preparing an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa to carry out a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 2000) and 0.22 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0031] Example 7: A method for preparing an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa to carry out a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.2 kg of an antibacterial agent (a dispersion with a solid content of 20% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 700) and 0.49 kg of succinic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0032] Example 8: A method for preparing an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa to carry out a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.2 kg of an antibacterial agent (a dispersion with a solid content of 30% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 700) and 0.87 kg of sebacic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and the reaction continued for 2 h to produce an antibacterial nylon 6 elastomer.

[0033] Example 9: A preparation method of an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water) and 0.02 kg of phosphorous acid are added into a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle is heated to 250 °C, and a ring-opening prepolymerization reaction is carried out for 2 h under the condition that the pressure is maintained at 600 kPa. After the prepolymerization reaction is completed, the polymerization kettle is quickly depressurized to normal pressure, and then 0.1 kg of an antibacterial agent (a dispersion with a solid content of 40% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) is added into the polymerization kettle and stirred rapidly for 15 min; then 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid are added into the polymerization kettle and stirred at 250 °C under normal pressure for 1.5 h, and then the reaction kettle is evacuated to -50 kPa and the reaction continues for 2 h to produce the antibacterial nylon 6 elastomer.

[0034] Example 10: A preparation method of an antibacterial nylon 6 elastomer, comprising the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water) and 0.02 kg of phosphorous acid are added into a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle is heated to 250 °C, and a ring-opening prepolymerization reaction is carried out for 2 h under the condition that the pressure is maintained at 600 kPa. After the prepolymerization reaction is completed, the polymerization kettle is quickly depressurized to normal pressure, and then 0.5 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) is added into the polymerization kettle and stirred rapidly for 15 min; then 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid are added into the polymerization kettle and stirred at 250 °C under normal pressure for 1.5 h, and then the reaction kettle is evacuated to -50 kPa and the reaction continues for 2 h to produce the antibacterial nylon 6 elastomer.

[0035] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that no antibacterial agent is added, and it comprises the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water) and 0.02 kg of phosphorous acid are added into a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle is heated to 250 °C, and a ring-opening prepolymerization reaction is carried out for 2 h under the condition that the pressure is maintained at 600 kPa. After the prepolymerization reaction is completed, the polymerization kettle is quickly depressurized to normal pressure; then 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid are added into the polymerization kettle and stirred at 250 °C under normal pressure for 1.5 h, and then the reaction kettle is evacuated to -50 kPa and the reaction continues for 2 h to produce the antibacterial nylon 6 elastomer.

[0036] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that the molecular weight of the polyetheramine is 400, and it comprises the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle was heated to 250 °C, and a ring-opening prepolymerization reaction was carried out at a pressure maintained at 600 kPa for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 400) and 1.1 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0037] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that the molecular weight of the polyetheramine is 5000, and it includes the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle was heated to 250 °C, and a ring-opening prepolymerization reaction was carried out at a pressure maintained at 600 kPa for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.2 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 5000) and 0.09 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0038] Comparative Example 4: The difference between Comparative Example 3 and Example 1 is that the dosage of the antibacterial agent is too low, and it includes the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle was heated to 250 °C, and a ring-opening prepolymerization reaction was carried out at a pressure maintained at 600 kPa for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure. Then, 0.05 kg of an antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min. Then, 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h. Then, the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0039] Comparative Example 5: The difference between Comparative Example 4 and Example 1 is that the dosage of the antibacterial agent is too high, including the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa for a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.8 kg of the antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 3 kg of polyetheramine (with a molecular weight of 700) and 0.63 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0040] Comparative Example 6: The difference between Comparative Example 6 and Example 1 is that the introduction of the polyetheramine soft segment is too low, including the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa for a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of the antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 0.5 kg of polyetheramine (with a molecular weight of 700) and 0.1 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0041] Comparative Example 7: The difference between Comparative Example 7 and Example 1 is that the introduction of the polyetheramine soft segment is too high, including the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to a polymerization kettle under the protection of an inert atmosphere. The temperature of the polymerization kettle was raised to 250 °C, and the pressure was maintained at 600 kPa for a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction was completed, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of the antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, with a particle size of 20 - 50 nm) was added to the polymerization kettle and rapidly stirred for 15 min; then 1.2 kg of polyetheramine (with a molecular weight of 700) and 2.5 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0042] Comparative Example 8: The difference between Comparative Example 8 and Example 1 is that the antibacterial agent is zinc oxide modified with surface carboxyl groups, and the other conditions are the same as those in Example 1.

[0043] Comparative Example 9: The difference between Comparative Example 9 and Example 1 is that the antibacterial agent is zinc oxide modified with surface amino groups, and the other conditions are the same as those in Example 1.

[0044] Comparative Example 10: The difference between Comparative Example 10 and Example 1 is that the antibacterial agent is added before the ring-opening prepolymerization of caprolactam, and polyetheramine and adipic acid are added after the ring-opening prepolymerization, including the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), 0.02 kg of phosphorous acid, and 0.2 kg of antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, particle size 20 - 50 nm) were added to a polymerization kettle under the protection of an inert atmosphere. The polymerization kettle was heated to 250 °C, and the pressure was maintained at 600 kPa for a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction ended, the polymerization kettle was quickly depressurized to atmospheric pressure; then 3 kg of polyetheramine (molecular weight 700) and 0.63 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0045] Comparative Example 11: The difference between Comparative Example 11 and Example 1 is that polyetheramine, dibasic acid, and the antibacterial agent are added to the polymerization kettle simultaneously, including the following steps: 10 kg of caprolactam, 0.3 kg of water (deionized water), and 0.02 kg of phosphorous acid were added to the polymerization kettle under the protection of an inert atmosphere. The polymerization kettle was heated to 250 °C, and the pressure was maintained at 600 kPa for a ring-opening prepolymerization reaction for 2 h. After the prepolymerization reaction ended, the polymerization kettle was quickly depressurized to atmospheric pressure, and then 0.2 kg of antibacterial agent (a dispersion with a solid content of 50% made from zinc oxide modified with surface hydroxyl groups and water, particle size 20 - 50 nm), 3 kg of polyetheramine (molecular weight 700), and 0.63 kg of adipic acid were added to the polymerization kettle and stirred at 250 °C under atmospheric pressure for 1.5 h, and then the reaction kettle was evacuated to -50 kPa and continued to react for 2 h to produce an antibacterial nylon 6 elastomer.

[0046] Comparative Example 12: The difference between Comparative Example 12 and Example 1 is still that the antibacterial agent is directly added in solid form without using the dispersion form, and the other conditions are the same as those in Example 1.

[0047] Detection Example: The properties of the nylon 6 elastomers prepared in Examples 1 to 10 and Comparative Examples 1 to 12 were tested. The test items included: relative viscosity, melting point, hardness, tensile strength, elongation at break, notched impact strength, and Escherichia coli bacteriostatic rate. The relative viscosity and melting point were tested according to the methods disclosed in GB / T 38138 "Test Methods for Fiber Grade Polycaprolactam (PA6) Chips". The tensile strength, elongation at break, and notched impact strength were tested according to the methods disclosed in GB / T 1040 "Determination of Tensile Properties of Plastics" and GB / T 1843 "Determination of Izod Impact Strength of Plastics". The Escherichia coli bacteriostatic rate was tested according to the methods disclosed in AATCC100 "Test Methods for Antibacterial Properties of Textiles". The test results are shown in Table 1. As shown in Table 1, the nylon 6 elastomers prepared in Examples 1 to 10 without using the technical solution provided by the present invention had a relative viscosity of 2.67 to 2.86, a melting point of 194 to 216 °C, a hardness of 53 to 69 D, a tensile strength of 33 to 72 MPa, an elongation at break difference rate of 570 to 1200%, and an Escherichia coli bacteriostatic rate of 93 to 99%. These results indicate that the nylon 6 elastomers prepared by the present invention have excellent elastic properties, softness, and antibacterial properties.

[0048] In Comparative Example 1, no antibacterial agent was used, and it was found that the nylon 6 elastomer prepared in Comparative Example 1 did not have a bacteriostatic effect.

[0049] In Comparative Examples 2 and 3, the molecular weight of the polyetheramine was explored. The results showed that the materials of the nylon 6 elastomers prepared in Comparative Example 2 with too low a molecular weight of the polyetheramine and in Comparative Example 3 with too high a molecular weight of the polyetheramine were severely sticky and could not be used subsequently. In addition, the results of Examples 1, 4, 5, and 6 showed that nylon elastomers with excellent material properties could be successfully polymerized when the molecular weight of the polyetheramine was 700 to 2000.

[0050] In Comparative Example 4, the dosage of the antibacterial agent was too low, and it was found that the nylon 6 elastomer prepared in Comparative Example 4 did not have a bacteriostatic effect. In Comparative Example 5, the dosage of the antibacterial agent was too high, and it was found that there were many antibacterial agent agglomeration particles in the melt of the nylon 6 elastomer prepared in Comparative Example 5. These results indicate that the dosage of the antibacterial agent used in the present invention also has an important impact on the properties of the nylon elastomer. If the dosage of the antibacterial agent is too small, the nylon elastomer will not have a bacteriostatic effect; if the dosage of the antibacterial agent is too large, it will cause the antibacterial agent to form agglomeration particles in the melt of the nylon elastomer.

[0051] Too little polyetheramine soft segment was introduced in Comparative Example 6. As a result, it was found that the elastic properties of the nylon elastomer prepared in Comparative Example 6 were significantly reduced and could not meet the application requirements. Too much polyetheramine soft segment was introduced in Comparative Example 7. As a result, it was found that the material of the nylon elastomer prepared in Comparative Example 7 was severely sticky and could not be processed for use.

[0052] In Comparative Example 8 and Comparative Example 9, zinc oxide modified with surface carboxyl and zinc oxide modified with surface amino were used respectively. As a result, it was found that antibacterial agent aggregates were generated in the melts of the nylon elastomers prepared in Comparative Example 8 and Comparative Example 9.

[0053] In Comparative Example 10, an antibacterial agent was added during the ring-opening prepolymerization of caprolactam. As a result, it was found that antibacterial agent aggregates were generated in the melt of the nylon elastomer prepared in Comparative Example 10.

[0054] In Comparative Example 11, a polyetheramine, a dibasic acid and an antibacterial agent were simultaneously added to a polymerization kettle. As a result, it was found that antibacterial agent aggregates were generated in the melt of the nylon elastomer prepared in Comparative Example 11.

[0055] In Comparative Example 12, the inorganic antibacterial agent was not formulated into a dispersion liquid but the solid inorganic antibacterial agent was directly added. As a result, it was found that a large amount of antibacterial agent aggregates were generated in the melt of the nylon elastomer prepared in Comparative Example 12.

[0056] The above are only the preferred embodiments of the present invention and do not impose any limitation on the present invention. Any simple modification, change and equivalent transformation made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. An antibacterial nylon 6 elastomer, characterized in that, The raw materials include 10 - 100 parts of caprolactam, 0.1 - 0.5 part of catalyst, 5 - 10 parts of antibacterial agent, 10 - 100 parts of polyetheramine, 10 - 100 parts of dibasic acid and the balance of water, and the antibacterial agent includes an inorganic antibacterial agent modified with surface hydroxyl groups.

2. The antibacterial nylon 6 elastomer according to claim 1, wherein The inorganic antibacterial agent modified with surface hydroxyl groups is zinc oxide modified with surface hydroxyl groups, and the particle size of the inorganic antibacterial agent modified with surface hydroxyl groups is 20 - 50 nm.

3. The antibacterial nylon 6 elastomer according to claim 1, characterized in that, The antibacterial agent further includes water.

4. The antibacterial nylon 6 elastomer according to claim 1 or 3, characterized in that, The solid content of the antibacterial agent is 20 - 50%.

5. The antibacterial nylon 6 elastomer according to claim 1, characterized in that, The catalyst is one or more of phosphorous acid, zinc phosphite, sodium phosphite, potassium phosphite, boric acid and phosphoric acid; the dibasic acid is one or more of succinic acid, adipic acid and sebacic acid.

6. The antibacterial nylon 6 elastomer according to claim 1, wherein The molecular weight of the polyetheramine is 700 - 2000.

7. A method for preparing the antibacterial nylon 6 elastomer according to any one of claims 1 to 6, characterized in that It includes the following steps: Add caprolactam, water and catalyst into a reaction kettle for prepolymerization reaction. After the prepolymerization reaction is completed, add the antibacterial agent and stir evenly to prepare an inorganic prepolymer, and then add polyetheramine and dibasic acid into the inorganic prepolymer for polycondensation reaction to prepare an antibacterial nylon 6 elastomer.

8. The preparation method according to claim 7, characterized in that, According to the preparation method described in claim 5, the characteristics are that the conditions of the polycondensation reaction include: the temperature is 240 - 260 °C, the pressure is 300 - 600 kPa, and the reaction time is 1 - 5 h.

9. The preparation method according to claim 7, characterized in that, The conditions of the polycondensation reaction include: reacting at 240 - 260 °C under normal pressure for 1 - 2 h, and then evacuating to - 20 - - 50 kPa and continuing the reaction for 2 - 3 h.

10. The preparation method according to claim 7, characterized in that, After the prepolymerization reaction is completed, release the pressure to normal pressure.

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