An anti-aging high-color-absorbing hyperbranched nylon 6 resin and its preparation method

Abstract

The present invention discloses an anti-aging and highly color-absorbing hyperbranched nylon 6 resin and a preparation method thereof. The anti-aging and highly color-absorbing hyperbranched nylon 6 resin involved in the present invention has a structural feature as shown in Formula I. The preparation method includes: 1) using caprolactam as a polymerization monomer and a polybasic acid with an eight-arm structure as a branching agent; 2) using 4-amino-2,2,6,6-tetramethylpiperidine as a capping agent, and adding an ultraviolet absorber and a light shielding agent; 3) obtaining the anti-aging and highly color-absorbing hyperbranched nylon 6 resin through melt polycondensation. The anti-aging and highly color-absorbing hyperbranched nylon 6 resin involved in the present invention has the characteristics of simple synthesis route, environmentally friendly process, high melt fluidity, excellent anti-aging performance and physical and mechanical properties, etc.

Description

Technical Field

[0001] The present invention relates to a polymer and a preparation method thereof, and particularly to an anti-aging and high color-absorbing hyperbranched nylon 6 resin with a simple synthesis route, an environmentally friendly process, high melt fluidity, anti-aging property, high color-absorbing property and excellent physical and mechanical properties, and a preparation method thereof. Background Art

[0002] Nylon is a general term for resins containing repeating amide groups -[NHCO]- in the molecular chain. It is a thermoplastic resin with the largest output, the most varieties, the widest uses and excellent comprehensive properties among the five general engineering plastics. Common nylon resins (such as nylon 6, nylon 66, nylon 1010, etc.) are basically linear structures, while hyperbranched nylon is a new type of special nylon resin. Compared with linear nylon with the same molecular weight, it has characteristics such as a higher functionality on the molecular surface, a lower crystallinity, a small hydrodynamic volume, a low melt viscosity, and high melt fluidity. The most prominent characteristic is that the melt viscosity has nothing to do with the total molecular weight and only depends on the molecular weight of each arm. The properties of hyperbranched nylon are different from those of linear nylon because it has a smaller atomic spatial arrangement size, a spherical symmetric structure, a smaller intermolecular interaction, and no entanglement inside and outside the molecule. The solution and melt viscosities of hyperbranched nylon are much lower than those of linear nylon with the same molecular weight, and it has good wettability, which is particularly suitable for preparing highly filled composite materials. Its excellent fluidity broadens the application field of nylon materials, shortens the processing cycle, and reduces the system cost.

[0003] Chinese Patent CN200710036035.0 discloses a synthesis method of hyperbranched nylon 6. Dendritic polyamide-amine (PAMAM) is selected as a branching agent, and caprolactam and nylon 66 salt are used as polymerization monomers. Hyperbranched nylon 6 is obtained by hydrolysis ring-opening polymerization. Its melt fluidity is 2 to 3 times that of ordinary nylon with similar mechanical properties, and it has great improvements in aspects such as extrusion, spraying process and formability during the production process of nylon devices. However, the PAMAM branching agent selected in this patent has the defect of poor heat resistance, and it has a multi-terminal amino structure, which may cause partial crosslinking with nylon 66 salt during the polymerization process, resulting in uncontrollability of the production process.

[0004] Chinese Patent CN201110233490.6 discloses a method for preparing branched nylon resin, which includes the following steps: Mixing lactam monomer, catalyst and initiator to obtain a first mixture, wherein the initiator is polyether initiator and polyethyleneimine, and the polyether initiator is amino-terminated polyether and carboxyl-terminated polyether; Heating the first mixture to 200-300 °C, after the ring-opening reaction of the lactam monomer, a second mixture is obtained; Performing condensation polymerization on the second mixture to obtain branched nylon resin. Compared with the prior art, the melt index of the prepared branched nylon resin reaches about 30 g / 10 min, and at the same time, due to the presence of polyether or polyethyleneimine structure with good flexibility and low glass transition temperature, it exhibits good toughness. However, due to the relatively low degree of branching of the polyether initiator involved, the improvement of the melt fluidity of the branched nylon resin is relatively limited. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies existing in the prior art, and develop an anti-aging and highly color-absorbing hyperbranched nylon 6 resin with a simple synthesis route, environmentally friendly process, high melt fluidity, anti-aging property, easy color absorption property and excellent physical and mechanical properties.

[0006] To achieve the purpose of the present invention, the general inventive concept is: Selecting caprolactam as the polymerization monomer, using a polybasic acid with an eight-arm structure as the branching agent, 4-amino-2,2,6,6-tetramethylpiperidine as the end-capping agent, and adding an ultraviolet absorber and a light shielding agent, and then obtaining the anti-aging and highly color-absorbing hyperbranched nylon 6 resin through melt polycondensation.

[0007] The present invention is achieved through the following technical solutions:

[0008] An anti-aging and highly color-absorbing hyperbranched nylon 6 resin, which has the structural characteristics shown in Formula I.

[0009]

[0010] Formula I

[0011] A method for preparing an anti-aging and highly color-absorbing hyperbranched nylon 6 resin, which includes the following steps:

[0012] 1) Selecting caprolactam as the polymerization monomer, adding a catalyst, an initiator, and using a polybasic acid with an eight-arm structure as the branching agent;

[0013] 2) Using 4-amino-2,2,6,6-tetramethylpiperidine as the end-capping agent, and adding an ultraviolet absorber and a light shielding agent;

[0014] 3) Obtaining the anti-aging and highly color-absorbing hyperbranched nylon 6 resin through melt polycondensation.

[0015] The above catalyst is one of phosphoric acid, phosphorous acid, and sodium hypophosphite, and the addition amount is 0.1-0.5% of the mass of caprolactam.

[0016] The above initiator is water, and the addition amount is 5-10% of the mass of caprolactam.

[0017] One or two of the above polyacids with an eight-arm structure have the structure shown in Formula II, and the addition amount is 0.5-5.0% of the mass of caprolactam, preferably 1.0-3.0%.

[0018]

[0019] Formula II

[0020] The addition amount of the above 4-amino-2,2,6,6-tetramethylpiperidine is 0.2-2.0% of the mass of caprolactam, preferably 0.5-1.5%.

[0021] The above ultraviolet absorber is a high-temperature resistant ultraviolet absorber, and the temperature at which the weight loss is 1% is ≥300°C, and it is selected from DSunsorb TM UV-120, DSunsorb TM UV-360, DSunsorb TM UV-405, DSunsorb TM UV-1164, DSunsorb TM UV-1600, DSunsorb TM One or several of UV-3030, and the addition amount is 0.5-1.0% of the mass of caprolactam.

[0022] The above light shield is one or several of nano carbon black, nano titanium dioxide, nano zinc oxide, and nano lithopone, and the addition amount is 1.0-2.0% of the mass of caprolactam.

[0023] The above light shield is surface organically modified, and the surface organic modification is carried out by one or more surfactants among DISPEBYK-180, DISPEBYK-190, and DISPEBYK-2012. The specific modification method is: add the light shield, deionized water, and surface modifier into a beaker according to a mass ratio of 1:1-2:0.05-0.1, and disperse with a high-speed disperser at a speed of 800-1000 r / min for 0.5-2 hours to obtain the surface organically modified light shield.

[0024] The specific process of the above melt polycondensation is as follows: After feeding, the air in the high-temperature and high-pressure reactor is replaced with high-purity nitrogen 3 to 4 times, the temperature is raised to 205-220 °C, the pressure in the reactor is maintained at 1.8-2.2 MPa, the pressure is maintained for 1.0-2.0 h, the gas is slowly released, and the temperature is further raised to 240-255 °C. After maintaining the pressure in the reactor at 2.2-2.5 MPa and maintaining the pressure for 1.0-2.0 h, the gas is released to atmospheric pressure, the water in the system is discharged, and then the vacuum is gradually pumped to reduce the pressure of the system to -0.05 to -0.09 MPa, and the material is discharged to obtain the anti-aging and high-color-absorbing hyperbranched nylon 6 resin.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) A polybasic acid with an eight-arm structure is introduced as a branching agent, and a hyperbranched nylon 6 resin with a relative viscosity ≥ 2.0 is prepared by melt polycondensation. Its melt index ≥ 40.0 g / 10 min, showing excellent melt fluidity and processing performance, and is particularly suitable for the production of highly filled modified engineering plastic products.

[0027] (2) Using 4-amino-2,2,6,6-tetramethylpiperidine as a capping agent, combined with the characteristics of high surface functionality of hyperbranched nylon 6 molecules, the photo-stability performance of hyperbranched nylon 6 resin can be improved at the molecular level, and the high content of terminal amino groups also improves the color-absorbing performance of the resin.

[0028] (3) Combining the compounding technology, by compounding with functional additives such as ultraviolet absorbers and light shielding agents, the anti-aging performance of hyperbranched nylon 6 resin is further optimized, and there is almost no precipitation phenomenon of functional additives, and the service life of the product is significantly extended. Description of the Drawings

[0029] Figure 1 It is the infrared curve of the anti-aging and high-color-absorbing hyperbranched nylon 6 resin prepared in Example 1. Detailed Embodiments

[0030] The present invention will be further described below in conjunction with specific embodiments.

[0031] Example 1: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.20 kg of polybasic acid with an eight-arm structure, 0.10 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant ultraviolet absorber DSunsorb in sequence TM0.20 kg of surface organically modified nano-titanium dioxide (UV-120) was put into a 50 L high-temperature and high-pressure reactor, and the gas in the reactor was replaced with high-purity nitrogen 3 to 4 times. The temperature was raised to 210 °C, the pressure in the reactor was maintained at 1.9 MPa, and the pressure was kept for 1.5 h. Then, the gas was slowly released, and the temperature was further raised to 250 °C. The pressure in the reactor was maintained at 2.2 MPa, and after keeping the pressure for 1.0 h, the gas was released to atmospheric pressure, and the water in the system was discharged. Then, the system was gradually evacuated to reduce the pressure to -0.07 MPa, and the material was discharged to obtain the anti-aging and high-color-absorbing hyperbranched nylon 6 resin (its infrared curve is as shown in Figure 1 ).

[0032] Example 2: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.30 kg of polybasic acid with an eight-arm structure, 0.10 kg of end-capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant ultraviolet absorber DSunsorb TM 0.20 kg of surface organically modified nano-titanium dioxide (UV-120) was put into a 50 L high-temperature and high-pressure reactor, and the gas in the reactor was replaced with high-purity nitrogen 3 to 4 times. The temperature was raised to 210 °C, the pressure in the reactor was maintained at 1.9 MPa, and the pressure was kept for 1.5 h. Then, the gas was slowly released, and the temperature was further raised to 250 °C. The pressure in the reactor was maintained at 2.2 MPa, and after keeping the pressure for 1.0 h, the gas was released to atmospheric pressure, and the water in the system was discharged. Then, the system was gradually evacuated to reduce the pressure to -0.07 MPa, and the material was discharged to obtain the anti-aging and high-color-absorbing hyperbranched nylon 6 resin.

[0033] Example 3: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.40 kg of polybasic acid with an eight-arm structure, 0.10 kg of end-capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant ultraviolet absorber DSunsorb TM 0.20 kg of surface organically modified nano-titanium dioxide (UV-120) was put into a 50 L high-temperature and high-pressure reactor, and the gas in the reactor was replaced with high-purity nitrogen 3 to 4 times. The temperature was raised to 210 °C, the pressure in the reactor was maintained at 1.9 MPa, and the pressure was kept for 1.5 h. Then, the gas was slowly released, and the temperature was further raised to 250 °C. The pressure in the reactor was maintained at 2.2 MPa, and after keeping the pressure for 1.0 h, the gas was released to atmospheric pressure, and the water in the system was discharged. Then, the system was gradually evacuated to reduce the pressure to -0.07 MPa, and the material was discharged to obtain the anti-aging and high-color-absorbing hyperbranched nylon 6 resin.

[0034] Example 4: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.50 kg of polyacid with an octa-arm structure, 0.10 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant UV absorber DSunsorb TM UV-120, and 0.20 kg of surface organically modified nano-titanium dioxide, and put them into a 50 L high-temperature and high-pressure reactor. Then displace the gas in the reactor with high-purity nitrogen for 3 to 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and continue to heat up to 250 °C. Maintain the pressure in the reactor at 2.2 MPa, keep the pressure for 1.0 h, then release the gas to atmospheric pressure, drain the water in the system, and then gradually evacuate to make the system decompress to -0.07 MPa, and discharge the material to obtain the anti-aging high-color-absorbing hyperbranched nylon 6 resin.

[0035] Example 5: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.30 kg of polyacid with an octa-arm structure, 0.20 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant UV absorber DSunsorb TM UV-120, and 0.20 kg of surface organically modified nano-titanium dioxide, and put them into a 50 L high-temperature and high-pressure reactor. Then displace the gas in the reactor with high-purity nitrogen for 3 to 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and continue to heat up to 250 °C. Maintain the pressure in the reactor at 2.2 MPa, keep the pressure for 1.0 h, then release the gas to atmospheric pressure, drain the water in the system, and then gradually evacuate to make the system decompress to -0.07 MPa, and discharge the material to obtain the anti-aging high-color-absorbing hyperbranched nylon 6 resin.

[0036] Example 6: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.30 kg of polyacid with an octa-arm structure, 0.20 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant UV absorber DSunsorb TM UV-405, and 0.20 kg of surface organically modified nano-titanium dioxide, and put them into a 50 L high-temperature and high-pressure reactor. Then displace the gas in the reactor with high-purity nitrogen for 3 to 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and continue to heat up to 250 °C. Maintain the pressure in the reactor at 2.2 MPa, keep the pressure for 1.0 h, then release the gas to atmospheric pressure, drain the water in the system, and then gradually evacuate to make the system decompress to -0.07 MPa, and discharge the material to obtain the anti-aging high-color-absorbing hyperbranched nylon 6 resin.

[0037] Example 7: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.30 kg of polybasic acid with an octa-armed structure, 0.20 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant ultraviolet absorber DSunsorb TM UV-3030, and 0.20 kg of surface organically modified nano-titanium dioxide, put them into a 50 L high-temperature and high-pressure reactor, and displace the gas in the reactor with high-purity nitrogen for 3 - 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and continue to heat up to 250 °C, maintain the pressure in the reactor at 2.2 MPa, after keeping the pressure for 1.0 h, release the gas to atmospheric pressure, drain the water in the system, then gradually evacuate to make the system decompress to -0.07 MPa, and discharge the material to obtain the anti-aging high-color-absorbing hyperbranched nylon 6 resin.

[0038] Example 8: Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, 1.200 kg of deionized water, 0.30 kg of polybasic acid with an octa-armed structure, 0.20 kg of capping agent 4-amino-2,2,6,6-tetramethylpiperidine, and 0.10 kg of high-temperature resistant ultraviolet absorber DSunsorb TM UV-3030, and 0.30 kg of surface organically modified nano-zinc barium, put them into a 50 L high-temperature and high-pressure reactor, and displace the gas in the reactor with high-purity nitrogen for 3 - 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and continue to heat up to 250 °C, maintain the pressure in the reactor at 2.2 MPa, after keeping the pressure for 1.0 h, release the gas to atmospheric pressure, drain the water in the system, then gradually evacuate to make the system decompress to -0.07 MPa, and discharge the material to obtain the anti-aging high-color-absorbing hyperbranched nylon 6 resin.

[0039] Among them, the polybasic acid with an octa-armed structure used in Examples 1 - 4 is while the polybasic acid with an octa-armed structure used in Examples 5 - 8 is . In addition, the surface organically modified nano-titanium dioxide used in Examples 1 - 7 and the surface organically modified nano-zinc barium used in Example 8 are both modified with DISPEBYK-180. The specific modification method is: add the light shielding agent, deionized water, and surface modifier into a beaker according to the mass ratio of 1:2:0.05, and disperse them with a high-speed disperser at a speed of 800 r / min for 1 hour to obtain the surface organically modified light shielding agent.

[0040] Comparative Example 1

[0041] Weigh 20.00 kg of caprolactam, 0.03 kg of sodium hypophosphite, and 1.200 kg of deionized water in sequence, put them into a 50 L high-temperature and high-pressure reactor, and displace the gas in the reactor with high-purity nitrogen 3 to 4 times. Heat up to 210 °C, maintain the pressure in the reactor at 1.9 MPa, keep the pressure for 1.5 h, slowly release the gas, and then continue to heat up to 250 °C. Maintain the pressure in the reactor at 2.2 MPa. After keeping the pressure for 1.0 h, release the gas to atmospheric pressure, drain the water in the system, and then gradually evacuate to reduce the pressure of the system to -0.07 MPa. Discharge the material to obtain the conventional nylon 6 resin.

[0042] Table 1 Performance data of the anti-aging and highly color-absorbing hyperbranched nylon 6 resin prepared in each example and the comparative examples

[0043] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Amino group content, mmol / kg 55 59 62 65 72 73 73 73 42 Melt index, g / 10min 42.5 54.8 63.8 69.2 70.4 70.5 70.3 70.7 17.8 Tensile strength, MPa 75.6 74.8 73.4 73.2 70.3 69.6 69.5 70.1 67.2 Elongation at break, % 19.2 18.8 18.7 18.5 17.3 17.5 17.1 17.6 16.4 Flexural strength, MPa 96.2 95.8 95.1 94.2 92.0 91.8 91.6 91.2 89.4 Notched impact strength, MPa 8.2 8.0 7.9 7.6 6.9 6.7 6.8 6.4 6.1 Tensile strength after aging, MPa 70.2 69.6 68.8 68.1 68.8 68.2 67.8 68.4 47.1 Elongation at break after aging, % 18.1 17.9 17.5 17.2 16.8 16.9 16.7 17.0 10.2 Flexural strength after aging, MPa 90.0 89.2 89.0 88.5 87.9 87.5 87.1 87.0 68.5 Notched impact strength after aging, MPa 7.8 7.5 7.3 7.0 6.7 6.4 6.5 6.2 2.8 Color difference, nbs 4.3 4.4 4.5 4.7 3.4 3.6 3.3 3.1 12.5 Yellowness index 5.1 5.2 5.4 5.6 4.3 4.7 4.4 4.9 15.8

[0044] Melt index test conditions: Place the pellets in a constant temperature and humidity chamber for 24 h, and use a melt index instrument for testing. The test standard is GB / T 3682-2018.

[0045] Tensile strength and elongation at break test conditions: Place the tensile specimens in a constant temperature and humidity chamber for 24 h, and use a testing machine for testing. The test standard is GB / T 1040.2-2006.

[0046] Flexural strength test conditions: Place the flexural specimens in a constant temperature and humidity chamber for 24 h, and use a testing machine for testing. The test standard is GB / T 9341-2008.

[0047] Notched impact strength test conditions: Place the impact specimens in a constant temperature and humidity chamber for 24 h, and use a testing machine for testing. The test standard is GB / T 1043.1-2008.

[0048] Color difference test conditions: Mainly use a color difference meter to measure the color change of different samples before and after aging. Measure the straight-line distance between two different samples in the color space. The test standard is ASTM D2244.

[0049] Yellowness index test conditions: Mainly use a color difference meter to measure the degree of yellowing of different samples before and after aging. The test standard is ASTM D6290.

[0050] This patent uses ASTM G154 xenon arc lamp aging, with a lamp tube of 340 nm, simulating outdoor ultraviolet light, to age the nylon 6 and the anti-aging and highly color-absorbing hyperbranched nylon 6 resin.

[0051] As can be seen from the data in Table 1, compared with the conventional nylon 6 resin, the physical and mechanical properties of the anti-aging high color-absorbing hyperbranched nylon 6 resin involved in this patent are relatively close to it before aging treatment, but the melt index is increased by 2.4 to 4.0 times, showing excellent melt fluidity and processing performance, and is particularly suitable for the production of highly filled modified engineering plastic products; in addition, after aging treatment, the retention rate of the physical and mechanical properties of the anti-aging high color-absorbing hyperbranched nylon 6 resin involved in this patent is basically about 90%, while the physical and mechanical properties of the conventional nylon 6 resin decrease by more than 30%, and the color difference change and yellowness index of the anti-aging high color-absorbing hyperbranched nylon 6 resin are significantly lower than those of the conventional nylon 6 resin.

Claims

1. A method for preparing an aging-resistant, highly color-absorbing hyperbranched nylon 6 resin, characterized in that: The aging-resistant, highly color-absorbing hyperbranched nylon 6 resin has the structural characteristics shown in Formula I: The method comprises the following steps: 1) Caprolactam is selected as a polymerization monomer, a catalyst and an initiator are added, and a polyacid with an eight-arm structure is used as a branching agent; 2) using 4-amino-2,2,6,6-tetramethylpiperidine as a capping agent, and adding an ultraviolet absorber and a light shielding agent; 3) Melt polycondensation can obtain aging-resistant and highly color-absorbing hyperbranched nylon 6 resin.

2. The method according to claim 1, characterized in that The catalyst is one of phosphoric acid, phosphorous acid and sodium hypophosphite, and the added amount is 0.1-0.5% of the mass of caprolactam.

3. The method according to claim 1, characterized in that: The initiator is water, and the added amount is 5-10% of the mass of caprolactam.

4. The method according to claim 1, characterized in that The structure of the polyacid with eight-arm structure is one or a combination of two of those shown in Formula II, and the added amount is 0.5-5.0% of the mass of caprolactam.

5. The method according to claim 1, characterized in that The added amount of the 4-amino-2,2,6,6-tetramethylpiperidine is 0.2-2.0% of the mass of caprolactam.

6. The method according to claim 1, characterized in that The ultraviolet absorber is a high temperature resistant ultraviolet absorber, the temperature of 1% weight loss is ≥300°C, and is selected from DSunsorb TM UV-120, DSunsorb TM UV-360, DSunsorb TM UV-405, DSunsorb TM UV-1164, DSunsorb TM UV-1600, DSunsorb TM One or more of UV-3030, the addition amount is 0.5-1.0% of the mass of caprolactam.

7. The method according to claim 1, characterized in that The light shielding agent is one or more of nano carbon black, nano titanium dioxide, nano zinc oxide and nano zinc barium, and the added amount is 1.0-2.0% of the mass of caprolactam.

8. The method according to claim 1, characterized in that: The light shielding agent is surface-organically modified, and the surface organic modification is performed by one or more surfactants selected from DISPEBYK-180, DISPEBYK-190, and DISPEBYK-2012. The specific modification method is as follows: adding the light shielding agent, deionized water, and the surface modifier into a beaker in a mass ratio of 1:1-2:0.05-0.1, and dispersing them in a high-speed disperser at a speed of 800-1000 r / min for 0.5-2 hours to obtain the light shielding agent after surface organic modification.

9. The method according to claim 1, characterized in that: The specific process of the melt polycondensation is as follows: after feeding, the air in the high-temperature and high-pressure reactor is replaced with high-purity nitrogen for 3 to 4 times, the temperature is raised to 205 to 220° C., the pressure in the reactor is maintained at 1.8 to 2.2 MPa, the pressure is maintained for 1.0 to 2.0 hours, the gas is slowly released, and the temperature is continued to be raised to 240 to 255° C., the pressure in the reactor is maintained at 2.2 to 2.5 MPa, the pressure is maintained for 1.0 to 2.0 hours, the gas is released to normal pressure, the water in the system is discharged, and then the system is gradually vacuumed to reduce the pressure to -0.05 to -0.09 MPa, and the material is discharged to obtain the aging-resistant and highly color-absorbing hyperbranched nylon 6 resin.

Images