WO2021203240A1

WO2021203240A1 - Anti-static and anti-microbial nylon 6 and preparation method therefor

Info

Publication number: WO2021203240A1
Application number: PCT/CN2020/083534
Authority: WO
Inventors: 刘国; 钱阳; 李龙
Original assignee: 江苏弘盛新材料股份有限公司
Priority date: 2020-04-07
Filing date: 2020-04-07
Publication date: 2021-10-14

Abstract

The present invention provides a preparation method for anti-static and anti-microbial nylon 6, comprising the following steps: step I, adding caprolactam, nano-silver and deionized water into a high-pressure reaction kettle, filling the reaction kettle with protective gas to replace air, and carrying out a hydrolysis reaction of caprolactam to obtain a solution A; step II, putting the solution A prepared from step I and ethylene glycol into a polymerization reactor, filling the polymerization reactor with protective gas to replace air, adding concentrated sulfuric acid, raising the temperature up to 90-130°C, carrying out a normal-pressure reaction for 2-4 hours, then decreasing the pressure and removing water, maintaining the temperature at 90-130°C to continue the reaction for 1-3 hours, and lowering the temperature to obtain a solution B; and step III, adding caprolactam and a molecular weight regulating agent into the polymerization reactor in step II, under a protective atmosphere, heating to 260-280°C, carrying out a pressurized reaction for 2-4 hours, then lowering the temperature and decreasing the pressure, continuing the reaction for 1-2 hours, discharging the material, and carrying out extraction and drying, so as to obtain the anti-static and anti-microbial nylon 6. The present application enables nylon 6 to have a good anti-static property and anti-microbial property by means of modification on the nylon 6.

Description

Antistatic and antibacterial nylon 6 and preparation method thereof

Technical field

The invention relates to the technical field of antistatic and antibacterial nylon materials, in particular to an antistatic and antibacterial nylon 6 and a preparation method thereof.

Background technique

There are various kinds of microbes in nature. In daily life, microbes are inextricably linked with people. However, some bacteria, fungi, viruses, etc., as pathogens, seriously endanger human health and even endanger lives. According to statistics, the number of deaths caused by bacterial infections in the world is close to 20 million each year, accounting for about 30% of the total deaths. Statistics from the US "WHO" magazine in 1996 show that there were approximately 52 million deaths worldwide in 1995. Approximately 17 million people died due to bacterial infections. These diseases include cholera, pneumonia, disease, tuberculosis and hepatitis. As we all know, the outbreak of "mad cow disease" in the United Kingdom in the past ten years, the "foot-and-mouth disease" in South Korea and Japan, the "anthracnose" in the United States, the severe respiratory infection (SARS) that appeared in China in 2003, and the poultry that appeared in 2004 and continue to this day The flu has caused the entire world to panic, and the repeated disasters brought by bacteria have increased people's attention to disease control and prevention to an unprecedented level. In hospitals, the cross-infection rate exceeds 10%. It can be seen that pathogenic bacteria have indeed brought a huge threat to human health.

With the improvement of living standards, people have higher and higher requirements for the living environment. As a result, the production of antibacterial materials has become an emerging industry, and countries around the world have paid more attention to the research of antibacterial agents. From a microbiological point of view, the concept of antibacterial is different from disinfection in the control of germs. It does not require immediate killing of microorganisms harmful to human health or life and production environment, but focuses on long-term use In the process, inhibit the growth and reproduction of wounds and keep the environment clean and hygienic. What we usually call antibacterial often includes sterilization, mildew removal, disinfection and so on. Generally speaking, the requirements for antibacterial agents are: (l) antibacterial ability and broad-spectrum antibacterial properties; (2) persistence, that is, resistance to washing, abrasion, and long life; (3) weather resistance, that is, heat resistance, Resistant to sunlight, not easy to decompose and fail; (4) Compatibility or processability with the substrate, that is, it is easy to add to the substrate without discoloring and does not reduce product performance; (5) Safety, harmless to health, and does not cause Pollution to the environment; (6) Bacteria are not easy to develop drug resistance.

At present, the antibacterial modification method of nylon 6 is to add an antibacterial agent to the nylon 6 matrix. Common antibacterial agents can be divided into inorganic antibacterial agents and organic antibacterial agents. Compared with organic antibacterial agents, inorganic antibacterial agents have the advantages of continuity, durability, broad antibacterial spectrum, resistance to drug resistance, good heat resistance and high safety. In the current prior art, the addition of inorganic antibacterial agents can greatly reduce the mechanical properties of nylon 6 while improving the antibacterial properties of nylon 6.

In addition, nylon 6 molecules are covalently bonded, and there are fewer polar groups in the main chain structure. Therefore, nylon 6 has a larger surface resistance of 10 13 to 10 14 Ω, which is a good insulator. However, when friction occurs, static electricity will accumulate. In the fields of electrical and electronics, coal mines, textiles, etc., due to friction, squeezing and other reasons, static discharges can cause dust absorption, breakdown of electronic devices, and damage to integrated circuits. Discharge will cause dangerous accidents such as fires and explosions, which will have a greater adverse impact on industrial production and daily life. The current antistatic modification method of nylon 6 will also greatly reduce the mechanical properties of nylon 6.

Summary of the invention

In order to overcome the problem of improving the antistatic and antibacterial properties of nylon 6 on the basis of not affecting the performance of nylon 6 in the prior art, the present invention provides an antistatic and antibacterial nylon 6 and a preparation method thereof.

A preparation method of antistatic and antibacterial nylon 6 includes the following steps:

Step 1: Add caprolactam, nano silver and deionized water into the autoclave, fill it with protective gas to replace the air, and perform the hydrolysis reaction of caprolactam to obtain solution A;

Step 2: Put the solution A and ethylene glycol prepared in Step 1 into a polymerization reactor according to a mass ratio of 1:1-1:12. The polymerization reactor is filled with protective gas to replace air, and concentrated sulfuric acid is added. Raise the temperature to 90-130°C, react at normal pressure for 2-4 hours, then reduce the pressure to remove water, keep the temperature at 90-130°C and continue the reaction for 1-3 hours, and lower the temperature to obtain solution B;

Step three, add caprolactam and molecular weight regulator to the polymerization reactor in step two, heat to 260-280°C under a protective atmosphere, react under pressure for 2-4 hours, then lower the temperature and pressure, and continue the reaction for 1 to 2 hours , The material is discharged, extracted, and dried to obtain the antistatic and antibacterial nylon 6.

In a preferred embodiment of the present invention, the mass ratio of caprolactam, nano silver and deionized water in the step one is (1.5-4.5):(0.1-0.3):1.

In a preferred embodiment of the present invention, in the first step, first add caprolactam and deionized water into the autoclave, fill it with protective gas to replace air, heat up to 210-240°C, pressure 0.8-1.2MPa, and react 2-4 hours; then lower the temperature to 110-130°C and reduce the pressure to remove water to obtain solution A.

In a preferred embodiment of the present invention, in the second step, the solution A prepared in step one and polyethylene glycol are first put into a polymerization reactor in a mass ratio of 1:2-1:6, and the polymerization reaction Fill the vessel with protective gas to replace the air. When the temperature rises to 90-98°C, add concentrated sulfuric acid, continue to raise the temperature to 100-130°C, and react at normal pressure for 2-4 hours; then reduce the pressure to -0.02～-0.05MPa, except With water, keep the pressure at -0.02～-0.05MPa, keep the temperature at 100-130°C and continue to react for 1-3 hours, and lower the temperature to obtain solution B.

In a preferred embodiment of the present invention, the molecular weight of the polyethylene glycol in the second step is 400-1000

In a preferred embodiment of the present invention, the added amount of the concentrated sulfuric acid in the second step is 0.5-1% of the total weight of the solution A.

In a preferred embodiment of the present invention, the molecular weight regulator in step three is benzoic acid or acetic acid, and the added amount of the molecular weight regulator accounts for 0.2-0.5% of the total weight of caprolactam added in step three.

In a preferred embodiment of the present invention, in the step three, first add caprolactam and molecular weight modifier to the polymerization reactor in step two, under a protective atmosphere, increase the temperature at a rate of 8-12°C/10 min, and maintain The pressure is 0.03-0.08MPa, the temperature is raised to 260-280℃, and the temperature is kept for 2-4 hours; then the pressure is reduced to -0.02～-0.05MPa, the temperature is lowered to 240-260℃, and the temperature is kept for 1-2 hours. The antistatic and antibacterial nylon 6 is obtained by extracting and drying materials.

In a preferred embodiment of the present invention, the surface resistance of the antistatic and antibacterial nylon 6 is 10 ¹⁰ -10 ¹² Ω, the elongation at break is 43-55%, and the notched impact strength is 31-39 J/m.

Compared with the prior art, the beneficial effects of the present invention are:

(1) In this application, caprolactam, the main raw material for nylon 6 production, is made into a modified reagent and added to the production system of nylon 6, with a simple preparation process;

(2) In the preparation process of this application, the copolymerization modification effect is obvious, the antistatic property is high, the antibacterial property is good, and the elongation at break and the notched impact strength of the product are improved to different degrees. The quantity is comparable to the unmodified product, and it has excellent comprehensive performance.

Detailed ways

Hereinafter, the present invention will be further described in detail with reference to the embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention.

Example 1:

Step three, add caprolactam and molecular weight regulator to the polymerization reactor in step two, heat to 260-280℃ in a protective atmosphere, react under pressure for 2-4 hours, then lower the temperature and pressure, and continue the reaction for 1-2 hours , Discharging, extracting, and drying to obtain the antistatic and antibacterial nylon 6.

In this embodiment, the mass ratio of caprolactam, nano silver and deionized water in step one is (1.5-4.5):(0.1-0.3):1.

Further, in this embodiment, in step 1, first add caprolactam and deionized water into the autoclave, fill it with protective gas to replace air, heat up to 210-240°C, pressure 0.8-1.2MPa, reaction 2- 4 hours; then lower the temperature to 110-130°C and reduce the pressure to remove water to obtain solution A.

In this embodiment, in step 2, the solution A and polyethylene glycol prepared in step 1 are put into the polymerization reactor according to the mass ratio of 1:2-1:6, and the protection is filled in the polymerization reactor. Replace the air with natural gas. When the temperature rises to 90～98℃, add concentrated sulfuric acid, continue to raise the temperature to 100-130℃, and react at normal pressure for 2～4 hours; then reduce the pressure to -0.02～-0.05MPa, remove water, and keep the pressure at -0.02～-0.05MPa, keep the temperature at 100-130°C and continue to react for 1-3 hours, and lower the temperature to obtain solution B.

Further, in this embodiment, the molecular weight of the polyethylene glycol in step 2 is 400-1000.

Further, in this embodiment, the added amount of the concentrated sulfuric acid in step 2 is 0.5-1% of the total weight of solution A.

In this embodiment, the molecular weight regulator in step three is benzoic acid or acetic acid, and the added amount of the molecular weight regulator accounts for 0.2-0.5% of the total weight of caprolactam added in step three.

Further, in this embodiment, in step three, first add caprolactam and molecular weight modifier to the polymerization reactor in step two, in a protective atmosphere, increase the temperature at a rate of 8-12°C/10 min, and keep the pressure at 0.03-0.08MPa, the temperature is raised to 260-280℃, and the temperature is kept for 2-4 hours; then the pressure is reduced to -0.02～-0.05MPa, the temperature is lowered to 240-260℃, and the temperature is kept for 1-2 hours. After extraction and drying, the antistatic and antibacterial nylon 6 is obtained.

In this embodiment, the surface resistance of the antistatic and antibacterial nylon 6 is 10 ¹⁰ -10 ¹² Ω, the elongation at break is 43-55%, and the notched impact strength is 31-39 J/m.

Example 2:

To prepare antistatic and antibacterial nylon 6, the steps are as follows:

1) Add 100g of water to the reactor, turn on the stirring, and add 10g of nano silver and 200g of caprolactam into the reactor. Fill the kettle with high-purity nitrogen to replace the air in the kettle. After the replacement is completed, the temperature is 1.5℃. The temperature was gradually increased at a rate of /min, the temperature was increased to 220°C, the pressure was maintained at 0.8 MPa, and the reaction was kept warm for 2 hours. Gradually reduce the pressure to normal pressure, the temperature to 110°C, keep for 30 minutes, and remove the water through a water separator to obtain solution A.

2) Put the solution A and 600g PEG600 obtained in the first step of the reaction into the reaction kettle, turn on the stirring, use high-purity nitrogen to replace the air in the kettle, start to heat up, wait until the temperature rises to 98°C, add 2.5g concentrated sulfuric acid, and continue to increase the temperature React at 120°C under normal pressure for 2 hours. During the reaction, part of the water is discharged through the condensing water separator. After 2 hours of reaction, the pressure is reduced to -0.03MPa, and the reaction is continued at 120°C for 3 hours, and the temperature is lowered to obtain solution B.

3) Add 200g of solution B to the autoclave, add 1800g of caprolactam and 5g of benzoic acid to the kettle, replace the air in the kettle with high-purity nitrogen, raise the temperature to 270°C at a rate of 10°C/10min, and place the kettle The internal pressure is controlled at 0.03MPa, the heat preservation and pressure retention reaction is 3 hours, the pressure is reduced to -0.03MPa, the temperature is lowered to 250°C, the heat preservation reaction is continued for 1.5 hours, the material is discharged, and the extraction and drying are performed to obtain the antistatic and antibacterial nylon 6.

Example 3:

To prepare antistatic and antibacterial nylon 6, the steps are as follows:

1) Add 100g of water to the reactor, turn on the stirring, and add 15g of nano-silver and 200g of caprolactam into the reactor, fill the kettle with high-purity nitrogen, and replace the air in the kettle. After the replacement is completed, the temperature is 1.5℃. The temperature was gradually increased at a rate of /min, the temperature was increased to 230°C, the pressure was maintained at 1.0 MPa, and the reaction was kept warm for 4 hours. Gradually reduce the pressure to normal pressure, the temperature to 120°C, keep for 30 minutes, and remove the water through a water separator to obtain solution A.

2) Add the solution A and 600g PEG600 obtained in the first step of the reaction into the reaction kettle, turn on the stirring, replace the air in the kettle with high-purity nitrogen, start to heat up, wait for the temperature to rise to 90°C, add 2.5g of concentrated sulfuric acid, and continue to increase the temperature React at normal pressure for 4 hours at 100°C. During the reaction, part of the water is discharged through the condensing water separator. After reacting for 4 hours, the pressure is reduced to -0.02MPa, kept at 100°C and reacted for 2 hours, and the temperature is lowered to obtain solution B.

3) Add 400g of solution B into the autoclave, add 1600g of caprolactam, and 5g of benzoic acid to the kettle, replace the air in the kettle with high-purity nitrogen, raise the temperature to 275°C at a rate of 10°C/10min, and place the kettle The internal pressure is controlled at 0.04 MPa, the temperature is maintained for 3 hours, the pressure is reduced to -0.05 MPa, the temperature is lowered to 240° C, the temperature is continued for 1 hour, the material is discharged, and the extract is dried to obtain the antistatic and antibacterial nylon 6.

Example 4:

To prepare antistatic and antibacterial nylon 6, the steps are as follows:

1) Add 100g of water to the reactor, turn on the stirring, and add 20g of nano silver and 200g of caprolactam into the reactor. Fill the kettle with high-purity nitrogen to replace the air in the kettle. After the replacement is completed, the temperature is 1.5℃. The temperature was gradually increased at a rate of /min, the temperature was increased to 210°C, the pressure was maintained at 1.1 MPa, and the temperature was kept for 2 hours to react. Gradually reduce the pressure to normal pressure, the temperature to 130°C, keep the temperature for 30 minutes, and remove the water through a water separator to obtain solution A.

2) Add the solution A and 600g PEG600 obtained in the first step of the reaction into the reaction kettle, turn on the stirring, and use high-purity nitrogen to replace the air in the kettle, and then start to heat up. When the temperature rises to 96°C, add 2.5g of concentrated sulfuric acid and continue to increase the temperature. React at 110°C under normal pressure for 3 hours. During the reaction, part of the water is discharged through the condensing water separator. After reacting for 3 hours, the pressure is reduced to -0.02MPa, and the reaction is continued at 110°C for 2 hours, and the temperature is lowered to obtain solution B.

3) Add 100g of solution B into the autoclave, add 1900g of caprolactam and 6g of benzoic acid to the kettle, replace the air in the kettle with high-purity nitrogen, raise the temperature to 270°C at a rate of 10°C/10min, and place the kettle The internal pressure is controlled at 0.06MPa, the heat preservation and pressure retention reaction is 3 hours, the pressure is reduced to -0.05MPa, the temperature is lowered to 250°C, the heat preservation reaction is continued for 1.5 hours, the material is discharged, and the extraction and drying are performed to obtain the antistatic and antibacterial nylon 6.

Example 5:

To prepare antistatic and antibacterial nylon 6, the steps are as follows:

1) Add 100g of water to the reactor, turn on the stirring, and add 30g of nano silver and 150g of caprolactam into the reactor, fill the kettle with high-purity nitrogen, and replace the air in the kettle. After the replacement is completed, the temperature is 1.5℃. The temperature is gradually increased at a rate of /min, the temperature is increased to 240°C, the pressure is maintained at 1.2 MPa, and the reaction is kept for 2 hours. Gradually reduce the pressure to normal pressure, the temperature to 110°C, keep for 30 minutes, and remove the water through a water separator to obtain solution A.

2) Add the solution A and 200g PEG400 obtained in the first step of the reaction into the reaction kettle, turn on the stirring, use high-purity nitrogen to replace the air in the kettle, start to heat up, wait until the temperature rises to 98°C, add 2.5g of concentrated sulfuric acid, and continue to increase the temperature React at 130°C under normal pressure for 2 hours. During the reaction, part of the water is discharged through the condensing water separator. After reacting for 2 hours, the pressure is reduced to -0.05MPa, and the reaction is continued at 130°C for 1 hour, and the temperature is lowered to obtain solution B.

3) Put 80g of solution B into the autoclave, add 1920g of caprolactam and 6g of benzoic acid to the kettle, replace the air in the kettle with high-purity nitrogen, raise the temperature to 280°C at a rate of 10°C/10min, and place the kettle The internal pressure is controlled at 0.08 MPa, the heat preservation and pressure retention reaction is 2 hours, the pressure is reduced to -0.05 MPa, the temperature is lowered to 260° C., the heat preservation reaction is continued for 2 hours, the material is discharged, and the extraction and drying are performed to obtain the antistatic and antibacterial nylon 6.

Comparative ratio: 1

Add 1800g of caprolactam and 5g of benzoic acid into the autoclave, replace the air in the autoclave with high-purity nitrogen, raise the temperature to 270℃ at a rate of 10℃/10min, and control the inside pressure of the autoclave to 0.03MPa, keep warm and keep the pressure After reacting for 3 hours, the pressure is reduced to -0.03 MPa, the temperature is lowered to 250° C., the heat preservation reaction is continued for 1.5 hours, the material is discharged, and the extraction and drying are performed to obtain nylon 6.

The performance test of the prepared nylon 6 product showed that the antistatic and antibacterial nylon 6 prepared in Examples 2-5 of the present application has an effect on Escherichia coli and Staphylococcus aureus. The size of the inhibition zone is above 14.8mm and 15.6, respectively. mm or more, the zone of inhibition is much larger than that in Comparative Example 1. The surface resistance of the antistatic and antibacterial nylon 6 prepared in Examples 2-5 of the present application is lower than that of the nylon 6 that has not been copolymerized and modified in Comparative Example 1, that is, antistatic The effect is better. In addition, the other physical properties of the antistatic and antibacterial nylon 6 prepared in Examples 2-5 of this application are improved to different degrees compared with the unmodified product in Comparative Example 1, such as the elongation at break. The products of 2-5 are better than Comparative Example 1, and the products of Examples 2, 4, and 5 are better than Comparative Example 1 in terms of notched impact strength. It is comparable to unmodified products in tensile strength and flexural modulus, and has excellent comprehensive properties.

The above description shows and describes the preferred embodiments of the present invention. As mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as the exclusion of other embodiments, but can be applied to various other embodiments. Combinations, modifications and environments can be modified through the above teachings or technology or knowledge in related fields within the scope of the inventive concept described herein. The modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present invention, and should fall within the protection scope of the appended claims of the present invention.

Claims

A preparation method of antistatic and antibacterial nylon 6 is characterized in that it comprises the following steps:

Step 1: Add caprolactam, nano silver and deionized water into the autoclave, fill it with protective gas to replace the air, and perform the hydrolysis reaction of caprolactam to obtain solution A;

Step 2: Put the solution A and ethylene glycol prepared in Step 1 into a polymerization reactor according to a mass ratio of 1:1-1:12. The polymerization reactor is filled with protective gas to replace air, and concentrated sulfuric acid is added. Raise the temperature to 90-130°C, react at normal pressure for 2-4 hours, then reduce the pressure to remove water, keep the temperature at 90-130°C and continue the reaction for 1-3 hours, and lower the temperature to obtain solution B;

Step 3: Add caprolactam and molecular weight regulator to the polymerization reactor in Step 2, heat to 260-280°C under a protective atmosphere, and react under pressure for 2-4 hours, then lower the temperature and pressure, and continue the reaction for 1-2 hours , The material is discharged, extracted, and dried to obtain the antistatic and antibacterial nylon 6.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, wherein the mass ratio of caprolactam, nano silver and deionized water in step one is (1.5-4.5):(0.1-0.3):1 .
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, characterized in that: in the first step, caprolactam and deionized water are first added to the autoclave, filled with protective gas to replace the air, and the temperature is raised to 210 -240°C, pressure 0.8-1.2MPa, react for 2-4 hours; then lower the temperature to 110-130°C and reduce the pressure to remove water to obtain solution A.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, characterized in that: in the second step, the solution A and polyethylene glycol prepared in step one are first prepared in a mass ratio of 1:2-1: 6. Put it into the polymerization reactor, fill the polymerization reactor with protective gas to replace the air, when the temperature rises to 90～98℃, add concentrated sulfuric acid, continue to raise the temperature to 100-130℃, and react at normal pressure for 2～4 hours; Decrease the pressure to -0.02～-0.05MPa, remove water, keep the pressure at -0.02～-0.05MPa, keep the temperature at 100-130°C and continue the reaction for 1-3 hours, and lower the temperature to obtain solution B.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, wherein the molecular weight of the polyethylene glycol in the second step is 400-1000.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, characterized in that the added amount of the concentrated sulfuric acid in the second step is 0.5-1% of the total weight of the solution A.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, wherein the molecular weight regulator in step three is benzoic acid or acetic acid, and the added amount of the molecular weight regulator accounts for the addition of caprolactam in step three. 0.2-0.5% of total weight.
The method for preparing antistatic and antibacterial nylon 6 according to claim 1, characterized in that: in the third step, first add caprolactam and molecular weight regulator to the polymerization reactor in step two, and in a protective atmosphere, 8 -12℃/10min speed up the temperature, and keep the pressure 0.03-0.08MPa, the temperature rises to 260-280℃, keep the temperature for 2-4 hours; then reduce the pressure to -0.02～-0.05MPa and the temperature to 240- The temperature is 260° C., the reaction is kept for 1-2 hours, and the material is discharged, extracted, and dried to obtain the antistatic and antibacterial nylon 6.
An antistatic and antibacterial nylon 6 prepared according to the method for preparing an antistatic and antibacterial nylon 6 according to any one of claims 1-8.
The antistatic and antibacterial nylon 6 according to claim 9, wherein the surface resistance of the antistatic and antibacterial nylon 6 is 10 10 -10 12 Ω, the elongation at break is 43-55%, and the notched impact strength is 31. -39J/m.