Anti-aging composite material and multi-stage synergistic anti-aging treatment method of PA6 fiber

Abstract

The application relates to the technical field of high-molecular compounds, and provides an anti-aging composite material and a PA6 fiber multi-stage synergistic anti-aging treatment method, which comprises the following components according to mass percentage: 94-97% of PA6 resin; 1.5-3% of a composite antioxidant; 0.8-2% of modified cerium oxide; and 0.5-1% of a lubricant. The preparation steps of the modified cerium oxide include weighing a predetermined amount of nano cerium oxide and a silane coupling agent; the silane coupling agent is configured into a 10% concentration solution, heated to generate a hydrolysis reaction, and hydrolyzed silane coupling agent is prepared; and then the nano cerium oxide is added, heated to generate a coupling reaction, and modified cerium oxide is prepared. Therefore, the composite antioxidant and the modified cerium oxide have unique anti-oxidation effects in each oxidation stage of fiber production. The anti-aging ability of the fiber is significantly improved. The smoothness of the fiber surface is good, the spinning breakage rate is low, and the quality of the textile finished product is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer compounds, and in particular relates to an anti-aging composite material and a multi-stage coordinated anti-oxidation and aging treatment method for PA6 fibers. Background Art

[0002] PA6 (polycaprolactam) fiber is widely used in automotive, textile and other fields due to its high strength, wear resistance and chemical resistance. However, the amide bonds in its molecular chain are susceptible to thermal oxidative aging and ultraviolet rays, resulting in a decrease in mechanical properties.

[0003] Existing public anti-aging methods, such as Chinese patent application CN117844242A, disclose a highly wear-resistant glass fiber-reinforced nylon material and its preparation method, which involves "weighing nylon resin, antioxidant, lubricant, anti-wear agent, nano-cerium oxide, titanium dioxide, and coupling agent according to parts by weight, uniformly mixing these raw materials, and then adding them through the main feed port of a twin-screw extruder." This application adds the antioxidant, nano-cerium oxide, coupling agent, and other anti-aging components together during the mixing process, resulting in the overall anti-aging effect of the product being a mechanical superposition of the effects of each component, leading to a bottleneck in improving the product's anti-aging performance. Summary of the Invention

[0004] In view of the above-mentioned defects, the present invention mainly provides an anti-aging composite material to solve the technical problem of the bottleneck in improving the anti-aging performance of PA6 products.

[0005] In order to solve the above problems, the present invention provides an anti-aging composite material, which comprises the following components by mass percentage:

[0006] PA6 resin: 94-97%;

[0007] Compound antioxidant: 1.5-3%;

[0008] Modified cerium oxide: 0.8-2%;

[0009] Lubricant: 0.5-1%.

[0010] According to the anti-aging composite material of the present invention, the composite antioxidant is a compound of antioxidant 1010 and AT-626, and the weight ratio of the two is 2:1.

[0011] According to the anti-aging composite material of the present invention, the preparation steps of the composite antioxidant are: respectively weighing antioxidant 1010 and AT-626 according to the weight ratio, and then mixing the two at a rotation speed of 20-30 rpm for 30-40 minutes.

[0012] According to the anti-aging composite material of the present invention, the antioxidant 1010 and AT-626 of the composite antioxidant are dried before mixing;

[0013] The drying treatment step is: both are placed in a vacuum drying oven, temperature 60±5℃, vacuum degree ≤100Pa, drying 4-6 hours.

[0014] The preparation step of the modified cerium oxide according to the anti-aging composite material of the application comprises:

[0015] A predetermined amount of nano cerium oxide and silane coupling agent are weighed, and the mass ratio of the two is 1:0.05-0.2;

[0016] The silane coupling agent is configured into a solution with a concentration of 10%, and a hydrolysis reaction occurs under heating to prepare a hydrolyzed silane coupling agent;

[0017] Nano cerium oxide is further added, and a coupling reaction occurs under heating to prepare modified cerium oxide; the heating temperature is 120℃, and the reaction time is 30-100min.

[0018] The particle size of the nano cerium oxide in the anti-aging composite material according to the application is not more than 50nm.

[0019] The lubricant in the anti-aging composite material according to the application is calcium stearate.

[0020] A multi-stage synergistic anti-aging treatment method for PA6 fibers comprises the following steps:

[0021] S1, prepare materials of each component according to the mass ratio of the anti-aging composite material;

[0022] S2, divide the composite antioxidant into two parts;

[0023] S3, in the initial stage of PA6 resin melt spinning, the melting temperature is ≤220℃; the first part of the composite antioxidant is added;

[0024] S4, in the final stage of PA6 resin melt spinning, the melting temperature is 240-260℃; the second part of the composite antioxidant and the modified cerium oxide are added;

[0025] S5, in the yarn cooling stage, microwave irradiation treatment is performed on the PA6 fibers; the microwave frequency is 2.45GHz; the irradiation power is 300-500W; and the irradiation time is 10-20s.

[0026] According to the multi-stage synergistic anti-aging treatment method for PA6 fibers according to the application, the PA6 resin in the S1 step is vacuum dried at 100℃ for 4 hours, so that the moisture content is ≤0.02%.

[0027] According to the multi-stage synergistic anti-aging treatment method for PA6 fibers according to the application, the lubricant is added in the S3 step.

[0028] In summary, the anti-aging composite material of the present invention, including its composite antioxidant and modified cerium oxide, produces unique antioxidant effects at each oxidation stage of fiber production. The present invention also provides a multi-stage synergistic anti-oxidative aging treatment method for PA6 fibers, significantly enhancing the fiber's aging resistance. Furthermore, the fiber surface is smoother, the spinning breakage rate is lower, and the quality of the finished textile product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the hydrolysis reaction of the silane coupling agent of the present invention;

[0030] Figure 2 This is a schematic diagram of the coupling reaction of cerium oxide and hydrolyzed KH-550 of the present invention;

[0031] Figure 3 This is a schematic diagram of the grafting reaction between the modified cerium oxide and PA6 of the present invention. DETAILED DESCRIPTION

[0032] See also Figure 1 The present invention provides an anti-aging composite material, comprising the following components by mass percentage:

[0033] PA6 resin: 94-97%;

[0034] Compound antioxidant: 1.5-3%;

[0035] Modified cerium oxide: 0.8-2%;

[0036] Lubricant: 0.5-1%.

[0037] Optionally, the lubricant of the present invention is calcium stearate.

[0038] As an embodiment, the composite antioxidant of the present invention is a compound of antioxidant 1010 and AT-626, and the weight ratio of the two is 2:1;

[0039] Furthermore, the preparation steps of the composite antioxidant are as follows: antioxidant 1010 (chemical name: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, white powder) and AT-626 (chemical name: bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, light yellow powder) are weighed respectively according to the weight ratio; then the two are added to the mixing bin of a high-speed mixer and mixed at a speed of 20-30 rpm for 30-40 minutes.

[0040] To prevent the antioxidant from hydrolyzing or agglomerating due to moisture during the subsequent melting process, the antioxidant 1010 (hindered phenol) and AT-626 (phosphite) of the composite antioxidant of the present invention are preferably dried before mixing.

[0041] The drying process comprises placing the two in a vacuum drying oven at a temperature of 60±5° C. and a vacuum degree of ≤100 Pa, and drying for 4-6 hours.

[0042] As an embodiment, the preparation steps of the modified cerium oxide of the present invention include:

[0043] Weigh the predetermined amount of nano-cerium oxide and silane coupling agent (KH-550), with the mass ratio of the two being 1: 0.05 ~ 0.2;

[0044] See also Figure 1 , preparing a 10% concentration solution of the silane coupling agent, heating it to cause a hydrolysis reaction, and preparing a hydrolyzed silane coupling agent;

[0045] See also Figure 2 Then, nano-cerium oxide is added and heated to produce a coupling reaction to obtain modified cerium oxide; the heating temperature is 120°C and the reaction time is 30-100 minutes.

[0046] Optionally, the particle size of nano-cerium oxide does not exceed 50 nm and has good dispersibility.

[0047] The present invention also provides a PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method, comprising the following steps:

[0048] S1, preparing the materials of each component according to the mass ratio of the anti-aging composite material;

[0049] As a preferred solution, the PA6 resin is vacuum dried at 100°C for 4 hours to reduce its moisture content to ≤0.02%.

[0050] S2, the composite antioxidant was divided into two equal parts;

[0051] S3, the initial stage of PA6 resin melt spinning, the melting temperature is ≤220℃; the first batch of composite antioxidant is added;

[0052] In the present invention, a composite antioxidant is added at the initial stage of PA6 melting (temperature ≤ 220°C). The antioxidant 1010 in the composite antioxidant captures free radicals through a hydrogen donation mechanism, thereby removing free radicals in the initial stage of PA6 melt oxidation and inhibiting the oxidation of the PA6 melt at this stage.

[0053] S4, the final stage of PA6 resin melt spinning, the melt temperature is 240~260℃; the second part of the composite antioxidant and modified cerium oxide are added;

[0054] AT-626 in the composite antioxidant of the present invention eliminates peroxides produced during the oxidation process of PA6 melt by decomposing hydroperoxides, forming a "double blocking" mechanism with antioxidant 1010, achieving dynamic complementarity, and inhibiting the oxidation of PA6 melt during the extrusion process.

[0055] At the same time, AT-626 (decomposition temperature ≥ 220°C) and antioxidant 1010 (decomposition temperature ≤ 180°C) have different decomposition temperatures. The two are in different melting temperature ranges, forming a complementary relationship to avoid a gap in inhibiting oxidation.

[0056] See also Figure 3 , modified cerium oxide undergoes grafting reaction with PA6.

[0057] The modified cerium oxide of this invention is added to the PA6 melt at the later stages of extrusion (melting temperature 240-260°C) to reduce its decomposition at high temperatures, retaining sufficient reactants for the subsequent grafting reaction. The shear force of the extruder evenly disperses the modified cerium oxide powder into the PA6 melt, enhancing the grafting reaction.

[0058] At the same time, the modified cerium oxide particles can also fill the micro-cracks on the surface of PA6, reduce the oxygen permeation rate, and improve the antioxidant capacity of PA6 in the high temperature range of melt spinning (240-260°C).

[0059] Preferably, the melt spinning of the present invention is performed in a twin-screw extruder.

[0060] In one embodiment, the first portion of the composite antioxidant in step S3 can be added from the front feed port of the extruder; the second portion of the composite antioxidant and modified cerium oxide in step S4 can be added from the middle feed port or the rear feed port of the extruder. By utilizing the temperature difference of the extruder along the extrusion direction, the feeding operations at different steps are performed separately, achieving continuous production.

[0061] Optionally, the lubricant is added to the twin-screw extruder in step S3.

[0062] See also Figure 3 , S5, spinning cooling stage, the PA6 fiber is subjected to microwave irradiation treatment; microwave frequency: 2.45 GHz; irradiation power: 300-500 W; irradiation time: 10-20 s;

[0063] The local heating effect of microwave irradiation promotes the reaction between the amino group (-NH2) of the modified cerium oxide and the carboxyl group (-COOH) at the end of the PA6 molecular chain to form an amide bond (-NH-CO-), thereby anchoring the modified cerium oxide and preventing it from migrating to the fiber surface. This improves the uniformity of the distribution of the modified cerium oxide in the PA6 fiber, thereby improving the anti-aging performance of the PA6 fiber.

[0064] The present invention sets multiple groups of process parameters and prepares multiple PA6 fiber samples as examples.

[0065] At the same time, a conventional melt spinning process was adopted to prepare a comparative example sample.

[0066] In order to make the test results comparable, the melt spinning production parameters of the embodiment samples of the present invention and the comparative example samples were the same (melting temperature, extrusion time, equipment specifications, etc.).

[0067] After the preparation of each example sample and comparative example sample, the tensile strength was tested. Then all samples were artificially aged and then the tensile strength was tested again, and the tensile strength retention rate after artificial aging was calculated. Specifically:

[0068] The artificial aging steps of the sample in the embodiment are: thermal oxidative aging at 150° C. for 1000 hours.

[0069] The artificial aging steps of the comparative sample are: thermal oxidation aging at 150°C for 800 hours.

[0070] The samples of the embodiment and the comparative example after artificial aging treatment were selected for textile production, and their spinning breakage rates were tested.

[0071] The parameters and test results for each example and comparative example are shown in Table 1. (Note: Table 1 lists only the modified parameters; identical components and steps can be found in the previous text and are not repeated here.) Compared to untreated PA6 fibers, the PA6 fibers treated with the multi-stage synergistic antioxidant aging treatment method of this application retain high tensile strength after artificial aging, significantly enhancing the fiber's aging resistance. Furthermore, the fiber surface is smoother, and the spinning breakage rate is lower, improving the quality of the finished textile product.

[0072] Table 1 Parameters and test results of various embodiments and comparative examples

[0073]

[0074] In summary, the present invention provides an anti-aging composite material. Its composite antioxidant and modified cerium oxide exhibit unique antioxidant effects at each oxidation stage during fiber production. The present invention also provides a multi-stage synergistic anti-oxidative aging treatment method for PA6 fibers, significantly enhancing the fiber's anti-aging capabilities. Furthermore, the fiber surface is smoother, the spinning breakage rate is lower, and the quality of the finished textile product is improved.

[0075] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A multi-stage synergistic anti-oxidation and aging treatment method for PA6 fibers, characterized in that: The steps include: S1, preparing the materials of each component according to the predetermined mass ratio of the anti-aging composite material; The anti-aging composite material comprises the following components: PA6 resin: 94-97%; composite antioxidant: 1.5-3%; modified cerium oxide: 0.8-2%; Lubricant: 0.5-1%; The composite antioxidant is a compound of antioxidant 1010 and AT-626, and the weight ratio of the two is 2:1; The preparation steps of the modified cerium oxide include: Weigh a predetermined amount of nano-cerium oxide and a silane coupling agent in a mass ratio of 1:0.05-0.2; the silane coupling agent is KH-550; The silane coupling agent is prepared into a 10% concentration solution, and heated to cause a hydrolysis reaction to obtain a hydrolyzed silane coupling agent; Then add nano-cerium oxide and heat to produce a coupling reaction to obtain modified cerium oxide; the heating temperature is 120°C and the reaction time is 30-100 minutes; S2, the composite antioxidant was divided into two equal parts; S3, the initial stage of PA6 resin melt spinning, the melting temperature is ≤220℃; the first batch of composite antioxidant is added; S4, the final stage of PA6 resin melt spinning, the melt temperature is 240~260℃; the second part of the composite antioxidant and modified cerium oxide are added; S5, the spinning cooling stage, the PA6 fiber is subjected to microwave irradiation treatment; microwave frequency: 2.45 GHz; irradiation power: 300-500 W; irradiation time: 10-20 s.

2. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 1, characterized in that: The preparation steps of the composite antioxidant are as follows: antioxidant 1010 and AT-626 are weighed respectively according to a weight ratio, and then the two are mixed at a rotation speed of 20-30 rpm for 30-40 minutes.

3. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 2, characterized in that: The antioxidant 1010 and AT-626 of the composite antioxidant are dried before mixing; The drying process comprises placing the two in a vacuum drying oven at a temperature of 60±5° C. and a vacuum degree of ≤100 Pa for 4-6 hours.

4. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 1, characterized in that: The particle size of the nano-cerium oxide does not exceed 50 nm.

5. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 1, characterized in that: The lubricant is calcium stearate.

6. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 1, characterized in that: The PA6 resin in step S1 is vacuum dried at 100° C. for 4 hours to reduce its moisture content to ≤0.02%.

7. The PA6 fiber multi-stage synergistic anti-oxidation and aging treatment method according to claim 1, characterized in that: The lubricant is added in step S3.

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