Complex antioxidant composition and preparation method thereof, complex antioxidant master batch for polyamide 66 and preparation method of complex antioxidant master batch

Abstract

The invention relates to the technical field of antioxidants, and particularly discloses a composite antioxidant composition and a preparation method thereof, a composite antioxidant master batch for polyamide 66 and a preparation method of the composite antioxidant master batch. The composite antioxidant composition is prepared by mixing 25-50% of a phenolic antioxidant, 25-50% of a phosphite antioxidant phosphate compound, 5-15% of a synergist, 2-12% of a filler and 5-15% of a lubricant, the preparation method comprises the following steps: stirring and mixing the phenolic antioxidant, the phosphite antioxidant phosphate compound, the synergist, the filler and the lubricant to obtain the composite antioxidant composition. The composite antioxidant composition provided by the invention can effectively capture free radicals and inhibit oxidation reaction, and the anti-yellowing capability of the antioxidant composition in a high-temperature environment is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of antioxidants, and more specifically, to a composite antioxidant composition and a preparation method thereof. Background Art

[0002] Polyamide 66 (PA66) is an important engineering plastic, which is widely used in the fields of automotive, electronic and electrical, textile, and industry due to its excellent mechanical properties, heat resistance, and chemical resistance. However, polyamide 66 is prone to oxidative degradation and yellowing under high-temperature environments. The yellowing phenomenon not only affects the appearance of polyamide 66 but also reduces its physical properties and service life. Therefore, improving the anti-yellowing performance of polyamide 66 has become an important topic in materials science research.

[0003] Currently, regarding the anti-yellowing performance of polyamide 66, researchers have explored the effects of different phenolic antioxidants on the antioxidant performance of polyamide 66. The results show that the oxidative stability of polyamide 66 has been improved after adding antioxidants.

[0004] However, under high-temperature conditions, the migration rate of antioxidants is too fast. Therefore, after polyamide 66 is used for a period of time under high-temperature conditions, yellowing still occurs. Summary of the Invention

[0005] In order to improve the anti-yellowing performance of antioxidants at high temperatures, this application provides a composite antioxidant composition and a preparation method thereof.

[0006] In the first aspect, this application provides a composite antioxidant composition, adopting the following technical solution: A composite antioxidant composition is composed of the following components by weight percentage: Phenolic antioxidant: 25 - 50%; Phosphate complex of phosphite antioxidant: 25 - 50%; Synergist: 5 - 15%; Filler: 2 - 12%; Lubricant: 5 - 15%; The phenolic antioxidant includes one or more of Irganox 1010, Irganox 1076, Irganox1098, Irganox 1330, Irganox 3125, Irganox 3114, Irganox 245, Lowinox 1790, and Sumilizer GA80; The phosphite antioxidant phosphate complex includes one or more of Ultranox 626, Weston 618F, PEPQ, Doverphos S-9228, ADK STAB PEP-36, and BRUGGOLEN H10.

[0007] Under high-temperature conditions, the molecular chains of the polymer are prone to breakage, generating free radicals, which in turn trigger oxidation reactions. By adopting the above technical solution, since the phenolic antioxidants of the above types have excellent thermal stability, they can effectively inhibit the generation of free radicals at high temperatures; the phosphite antioxidant phosphate complex of the above types has a co-antioxidant that decomposes peroxides, which can decompose peroxide free radicals at high temperatures and protect the color of the material. Therefore, by compounding the phenolic antioxidants and the phosphite antioxidant phosphate complex of the above types in a certain proportion, the obtained antioxidant composition has higher stability, is more resistant to volatilization and migration, is suitable for high-temperature processing, effectively inhibits the initial oxidation of the polymer, blocks the secondary oxidation of the polymer, effectively improves the yellowing phenomenon of the polymer, and extends the lifespan of the polymer.

[0008] Preferably, the phenolic antioxidant includes Irganox1098 and Sumilizer GA80; the phosphite antioxidant phosphate complex includes Doverphos S-9228 and BRUGGOLEN H10.

[0009] Preferably, the phenolic antioxidant is composed of Irganox1098 and Sumilizer GA80 mixed in a weight ratio of 1:(1 - 3.52).

[0010] Preferably, the phosphite antioxidant phosphate complex is composed of Doverphos S-9228 and BRUGGOLEN H10 mixed, and the weight ratio of Irganox1098, Doverphos S-9228, and BRUGGOLEN H10 is 1:2:(1 - 2).

[0011] By adopting the above technical solution, since Irganox1098 and Doverphos S-9228 have high molecular weights and are resistant to volatilization, Sumilizer GA-80 can continuously provide antioxidant protection at high temperatures, and BRUGGOLEN H10 is a phosphorus-containing inorganic salt with very strong reducing properties, and the strong reducing properties endow it with very excellent anti-yellowing performance. Therefore, by compounding the above types of antioxidants, the prepared antioxidant composition has excellent anti-yellowing performance at high temperatures.

[0012] Preferably, the synergist is stearate or hydrotalcite or zinc oxide.

[0013] Preferably, the stearate includes zinc stearate, calcium stearate, magnesium stearate or aluminum stearate.

[0014] Preferably, the stearate is calcium stearate or magnesium stearate.

[0015] By adopting the above technical solution, the use of the synergist enables the antioxidant composition to more effectively inhibit the oxidation reaction at high temperatures, which is beneficial to improving the yellowing phenomenon of the polymer and extending the service life of the polymer.

[0016] Preferably, the filler includes nano-silica, nano-silicon nitride, nano-aluminum oxide, nano-calcium carbonate, nano-titanium dioxide or nano-clay.

[0017] Preferably, the filler is nano-silica.

[0018] By adopting the above technical solution, the addition of nano-scale fillers improves the dispersibility of the antioxidant in the polymer, which is beneficial to improving the mechanical properties and anti-yellowing properties of the polymer.

[0019] Preferably, the lubricant includes polyethylene wax, amide wax or paraffin wax.

[0020] Preferably, the lubricant is amide wax.

[0021] Preferably, the amide wax is ethylene bis-stearamide.

[0022] By adopting the above technical solution, adding the above types of lubricants to the antioxidant composition can not only promote the uniform dispersion of the antioxidant in the polymer, but also effectively reduce the melt viscosity of the antioxidant composition and reduce the oxidation risk caused by shear during processing.

[0023] In a second aspect, the present application provides a preparation method of a composite antioxidant composition, adopting the following technical solution: A preparation method of a composite antioxidant composition, comprising the following steps: Stir and mix a phenolic antioxidant, a phosphite antioxidant phosphate complex, a synergist, a filler and a lubricant to obtain a composite antioxidant composition.

[0024] By adopting the above technical solution, the present application only needs to simply mix the raw materials to obtain a composite antioxidant composition. Therefore, the preparation method of the present application has simple operation steps and is suitable for large-scale production.

[0025] In a third aspect, the present application provides a composite antioxidant masterbatch for polyamide 66, adopting the following technical solution: A composite antioxidant masterbatch for polyamide 66, comprising the following components in parts by weight: Polyamide 66 0 - 80 parts; The above composite antioxidant composition is 20 to 100 parts.

[0026] By adopting the above technical solution, for the composite antioxidant masterbatch for polyamide 66 of the present application, the content of the composite antioxidant composition can be adjusted from 20% to 100%, which is much higher than the content of the commercially available antioxidant masterbatch, and has a wider commercial application value.

[0027] Fourthly, the present application provides a preparation method for a composite antioxidant masterbatch for polyamide 66, adopting the following technical solution: A preparation method for a composite antioxidant masterbatch for polyamide 66, comprising the following steps: Mix the composite antioxidant composition and polyamide 66, and then extrude and pelletize to obtain the composite antioxidant masterbatch for polyamide 66; The temperature of the extrusion and pelletization is 50 to 150 °C.

[0028] By adopting the above technical solution, on the one hand, after simply mixing the composite antioxidant composition and polyamide 66 and then extruding and pelletizing, the masterbatch can be obtained. The preparation method is simple and suitable for large-scale production.

[0029] On the other hand, the melting point of the lubricant is relatively low. By compounding the synergist and the lubricant, the temperature of the extrusion and pelletization can be reduced to 50 to 145 °C. Compared with the extrusion and pelletization temperature under high-temperature conditions in the related art, the present application reduces the temperature of the extrusion and pelletization, effectively improving the activity of the antioxidant composition during high-temperature extrusion / injection molding and its thermal stability when applied in a high-temperature environment.

[0030] At the same time, in the total raw materials for the preparation of the composite antioxidant masterbatch for polyamide 66, since 15 to 20% of the components in the composite antioxidant composition can be melted, and then compounded with a specific lubricant, excellent processing performance is imparted to the composition. Therefore, when the content of the composite antioxidant composition is 100%, it can also be extruded and pelletized to form a composite antioxidant masterbatch with a smooth surface, having a high application range.

[0031] In summary, the present application has the following beneficial effects: 1. Since this application uses a specific type of phenolic antioxidant and a phosphite antioxidant phosphate complex compounded in a certain weight ratio, it can effectively capture free radicals, inhibit the occurrence of oxidation reactions, and significantly improve the yellowing resistance performance of the antioxidant composition in a high-temperature environment. At the same time, BRUGGOLEN_H10 has a higher phosphorus content and stronger reducibility, and has excellent short-term high-temperature yellowing resistance performance during processes such as extrusion and injection molding and aging at 200°C for half an hour. Compared with Doverphos S-9228, BRUGGOLEN_H10 tends to have short-term high-temperature yellowing resistance. For example, during the processing at 280°C, the long-term high-temperature aging effect of BRUGGOLEN_H10 is not very good. However, Doverphos S-9228 is relatively more balanced, providing better protection against yellowing during the processing at 280°C and also providing relatively good protection against yellowing during long-term thermal aging later. But compounding Doverphos S-9228 and BRUGGOLEN_H10 has a certain synergistic effect, taking into account the color protection during short-term processing and the color protection during long-term thermal aging later. The finally prepared composite antioxidant composition, when used in high-temperature granulation and multiple injection moldings, the sample obtained still has excellent yellowing resistance performance after aging at 90°C for 3 days under medium and low-temperature aging conditions. 2. The composite antioxidant masterbatch for polyamide 66 of this application has an antioxidant content as high as 20 - 100%, and has broad commercial value. 3. The preparation method of the composite antioxidant masterbatch for polyamide 66 of this application, by compounding a synergist, a lubricant, a phenolic antioxidant, and a phosphite antioxidant phosphate complex, reduces the extrusion granulation temperature, reduces the conditions at high temperatures, reduces the heat aging of polyamide 66 in the masterbatch, and improves the yellowing resistance performance of the composite antioxidant masterbatch for polyamide 66 in a high-temperature environment. Detailed implementation manners

[0032] The following further elaborates on this application in conjunction with examples.

[0033] Example 1 A composite antioxidant composition, each component and its corresponding weight (kg) are shown in the following table.

[0034]

[0035] The preparation method of the above composite antioxidant composition includes the following steps: Stir and mix the phenolic antioxidant, the phosphite antioxidant phosphate complex, the synergist, the filler, and the lubricant at 300 r / min for 10 min to obtain the composite antioxidant composition.

[0036] Examples 2 - 7 A composite antioxidant composition, which is different from that of Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0037]

[0038] Examples 8 - 10 A composite antioxidant composition, which is different from that of Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0039]

[0040] Example 11 A composite antioxidant composition, which is different from that of Example 1 in that the synergist is hydrotalcite and the lubricant is polyethylene wax A - C 540A.

[0041] Comparative Examples 1 - 2 A composite antioxidant composition, which is different from that of Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0042]

[0043] Comparative Examples 3 - 4 A composite antioxidant composition masterbatch, the components and their corresponding weights (kg) are shown in the following table.

[0044]

[0045] Application Example 1 A composite antioxidant masterbatch for polyamide 66, the components and their corresponding weights are shown in the following table.

[0046]

[0047] The preparation method of the above - mentioned composite antioxidant masterbatch for polyamide 66 includes the following steps: After drying polyamide 66 at 50°C for 6 h, add polyamide 66 into a twin - screw extruder in a side - feeding manner, add the composite antioxidant composition into the twin - screw extruder in a main - feeding manner, and then under the conditions of a main - machine speed of 15 HZ and a feeding speed of 10 HZ, carry out co - blending and extrusion granulation to obtain the composite antioxidant masterbatch for polyamide 66.

[0048] In the application example of this application, the twin - screw extruder, model HK - 26, is purchased from Nanjing Keya Twin - Screw Extruder; When carrying out extrusion granulation, the temperature of the first zone in the twin - screw extruder is 90°C, the temperature of the second zone is 100°C, the temperatures of the third to eighth zones are all 120°C, and the head temperature is 120°C.

[0049] Application Examples 2 - 10 A composite antioxidant masterbatch for polyamide 66, which is different from Application Example 1 in that each component and its corresponding weight are as shown in the following table.

[0050]

[0051] Application Example 11 A composite antioxidant masterbatch for polyamide 66, which is different from Application Example 1 in that the composite antioxidant composition used is the one prepared in Example 11.

[0052] In the preparation method of the above - mentioned composite antioxidant masterbatch for polyamide 66, during extrusion granulation, the temperature of the first zone in the twin - screw extruder is 80°C, the temperature of the second zone is 100°C, the temperatures of the third to eighth zones are all 110°C, and the head temperature is 110°C.

[0053] Comparative Application Examples 1 - 4 A composite antioxidant masterbatch, which is different from Application Example 1 in that each component and its corresponding weight are as shown in the following table.

[0054]

[0055] Yellowing resistance detection: After mixing and granulating the composite antioxidant masterbatch for polyamide 66 prepared in Application Examples 1 - 11 and the composite antioxidant masterbatch prepared in Comparative Application Examples 1 - 4 with polyamide 66 respectively, injection - molding them into sample pieces, and then conducting yellowing resistance detection on the sample pieces. The specific steps are as follows: (1) The formula of the sample pieces and their corresponding dosages are as shown in the following table.

[0056]

[0057] The preparation method of the above - mentioned sample pieces is as follows: (1) Preparation of resin particles After drying polyamide 66 at 85°C for 8 h, mix it with masterbatches of different formulas in a screw extruder, conduct extrusion granulation three times, and then use a pelletizer to pelletize, obtaining blank resin particles from the first extrusion granulation, blank resin particles from the third extrusion granulation, antioxidant resin particles from the first extrusion granulation, antioxidant resin particles from the third extrusion granulation, comparative antioxidant resin particles from the first extrusion granulation, and comparative antioxidant resin particles from the third extrusion granulation respectively.

[0058] During the above extrusion granulation, the temperature of the first zone in the twin - screw extruder is 230°C, the temperature of the second zone is 260°C, the temperatures of the third to eighth zones are all 270°C, and the head temperature is 275°C.

[0059] In this application, blank resin particles are prepared first. After each antioxidant resin particle or comparative antioxidant resin particle is extruded, the screw extruder and pelletizer are cleaned with the blank resin particles. For the first and third extrusions of each antioxidant resin particle, approximately 1000 g of particles from the middle section are taken as the raw materials for the antioxidant resin sample pieces.

[0060] (2) Preparation of sample pieces The blank resin particles obtained from the first extrusion granulation and the blank resin particles obtained from the third extrusion granulation are dried at 85 °C for 8 h, and then respectively added to an injection molding machine to be injection molded into antioxidant resin sample pieces with dimensions of 80 mm * 60 mm * 2 mm. Sampling starts after continuous injection molding of 10 molds for each sample piece, and the blank resin sample pieces obtained from the first extrusion and the blank resin sample pieces obtained from the third extrusion are obtained respectively.

[0061] The antioxidant resin particles obtained from the first extrusion granulation and the antioxidant resin particles obtained from the third extrusion granulation are dried at 85 °C for 8 h, and then respectively added to an injection molding machine to be injection molded into antioxidant resin sample pieces with dimensions of 80 mm * 60 mm * 2 mm. Sampling starts after continuous injection molding of 10 molds for each sample piece, and the antioxidant resin sample pieces obtained from the first extrusion and the antioxidant resin sample pieces obtained from the third extrusion are obtained respectively.

[0062] The comparative antioxidant resin particles obtained from the first extrusion granulation and the comparative antioxidant resin particles obtained from the third extrusion granulation are dried at 85 °C for 8 h, and then respectively added to an injection molding machine to be injection molded into antioxidant resin sample pieces with dimensions of 80 mm * 60 mm * 2 mm. Sampling starts after continuous injection molding of 10 molds for each sample piece, and the comparative antioxidant resin sample pieces obtained from the first extrusion granulation and the comparative antioxidant resin sample pieces obtained from the third extrusion granulation are obtained respectively.

[0063] The injection molding machine, model MA860 / 280GII, is purchased from Haitian. During the above injection molding process, the temperature of the first zone of the injection molding machine is 270 °C, the temperature of the second zone is 265 °C, the temperature of the third zone is 260 °C, and the temperature of the fourth zone is 220 °C.

[0064] (3) Detection of sample pieces Referring to the ASTM E313-20 standard, the YI values (yellow index) of the antioxidant resin sample pieces obtained from the first extrusion, the antioxidant resin sample pieces obtained from the third extrusion, the comparative antioxidant resin sample pieces obtained from the first extrusion, the comparative antioxidant resin sample pieces obtained from the third extrusion, the blank resin sample pieces obtained from the first extrusion, and the blank resin sample pieces obtained from the third extrusion are detected, and are respectively recorded as the YI value of the first extrusion and the YI value of the third extrusion.

[0065] Referring to the ASTM E313-20 standard, after aging the antioxidant resin sample sheet extruded for the first time, the comparative antioxidant resin sample sheet extruded for the first time, and the blank resin sample sheet at 90 °C for 3 days, the YI value of each day was measured respectively, recorded as the YI value after aging at 90 °C, and then ΔYI was calculated. The calculation formula is: ΔYI = YI value after aging at 90 °C - YI value of the first extrusion.

[0066] (4)Test data The test data of the sample sheet extruded three times are shown in the following table.

[0067]

[0068] By analyzing the data in the above table, it can be seen that compared with sample sheets 1-10, the YI values of the first extrusion and the third extrusion of the comparative sample sheets 1-4 increased significantly. This shows that in the total raw materials for preparing the sample sheets in this application, using the composite antioxidant masterbatch for polyamide 66 prepared by Application Examples 1-10 can improve the anti-yellowing performance of the sample sheets during multiple extrusions.

[0069] Compared with sample sheet 1, the YI values of the first extrusion and the third extrusion of the comparative sample sheets 1-2 increased significantly. This shows that in the total raw materials for preparing the sample sheets in this application, when the composite antioxidant masterbatch for polyamide 66 is prepared by compounding specific types of phenolic antioxidants and phosphite antioxidant phosphate complexes, the anti-yellowing performance of the sample sheets can be improved.

[0070] Compared with sample sheet 1, the YI values of the first extrusion and the third extrusion of the comparative sample sheets 3-4 increased significantly. This shows that in the total raw materials for preparing the sample sheets in this application, by controlling the compounding ratio of phenolic antioxidants and phosphite antioxidant phosphate complexes, the anti-yellowing performance of the sample sheets can be improved.

[0071] Compared with sample sheet 1, the YI values of the first extrusion and the third extrusion of sample sheet 8 decreased significantly. This shows that in the total raw materials for preparing the sample sheets in this application, when the phosphite antioxidant phosphate complex in the composite antioxidant masterbatch for polyamide 66 is composed of a mixture of Doverphos S-9228 and BRUGGOLEN H10, and the phenolic antioxidant is composed of a mixture of Irganox1098 and Sumilizer GA80, the anti-yellowing performance of the sample sheets can be improved.

[0072] Compared with sample 1, the YI values of the first extrusion and the third extrusion of samples 9 and 10 are significantly reduced. This indicates that when the Irganox 1098, Doverphos S-9228, and BRUGGOLEN H10 in the composite antioxidant masterbatch for polyamide 66 are mixed in a weight ratio of 1:2:(1-2) in the total raw materials for preparing the samples of this application, the samples have high anti-yellowing performance.

[0073] The test data of the samples after aging at 90°C for 3 days are shown in the following table.

[0074]

[0075] By analyzing the data in the above table, it can be seen that compared with samples 1-11, the ΔYI values after aging for 1 day, the ΔYI values after aging for 2 days, and the ΔYI values after aging for 3 days of comparative samples 1-4 are significantly increased. This indicates that in the total raw materials for preparing the samples of this application, using the composite antioxidant masterbatch for polyamide 66 prepared by Application Examples 1-10 can improve the anti-yellowing performance of the samples after aging at 90°C for 3 days.

[0076] Compared with sample 1, the ΔYI values after aging for 1 day, the ΔYI values after aging for 2 days, and the ΔYI values after aging for 3 days of sample 8 are significantly reduced. This indicates that in the total raw materials for preparing the samples of this application, when the phosphite antioxidant phosphate complex in the composite antioxidant masterbatch for polyamide 66 is composed of a mixture of Doverphos S-9228 and BRUGGOLEN H10, and the phenolic antioxidant is composed of a mixture of Irganox 1098 and Sumilizer GA80, the anti-yellowing performance of the samples under high-temperature conditions can be improved.

[0077] Compared with sample 1, the ΔYI values after aging for 1 day, the ΔYI values after aging for 2 days, and the ΔYI values after aging for 3 days of samples 9 and 10 are significantly reduced. This indicates that when the Irganox 1098, Doverphos S-9228, and BRUGGOLEN H10 in the composite antioxidant masterbatch for polyamide 66 are mixed in a weight ratio of 1:2:(1-2) in the total raw materials for preparing the samples of this application, the samples have high anti-yellowing performance under high-temperature conditions.

[0078] Compared with sample 1, the ΔYI values after aging for 1 day, the ΔYI values after aging for 2 days, and the ΔYI values after aging for 3 days of sample 11 slightly increase. This indicates that in the total raw materials for preparing the samples of this application, when the stearate in the composite antioxidant masterbatch for polyamide 66 is calcium stearate and the amide wax is ethylene bisstearamide, the anti-yellowing performance of the samples under high-temperature conditions can be improved.

[0079] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A composite antioxidant composition, characterized in that, Composed of components in the following weight percentages: Phenolic antioxidant: 25 - 50%; Phosphite antioxidant phosphate complex: 25 - 50%; Synergist: 5 - 15%; Filler: 2 - 12%; Lubricant: 5 - 15%; The phenolic antioxidant includes Irganox1098 and Sumilizer GA80; the phosphite antioxidant phosphate complex is composed of Doverphos S-9228 and BRUGGOLEN H10 mixed in a weight ratio of 2:(1 - 2); The synergist is stearate; The lubricant is amide wax.

2. The composite antioxidant composition according to claim 1, wherein The stearate includes zinc stearate, calcium stearate, magnesium stearate or aluminum stearate.

3. The composite antioxidant composition according to claim 1, characterized in that The filler includes nano-silica, nano-silicon nitride, nano-aluminum oxide, nano-calcium carbonate, nano-titanium dioxide or nano-clay.

4. The preparation method of the composite antioxidant composition according to any one of claims 1 to 3, characterized in that, Including the following steps: Stir and mix the phenolic antioxidant, phosphite antioxidant phosphate complex, synergist, filler and lubricant to obtain a composite antioxidant composition.

5. A composite antioxidant masterbatch for polyamide 66, characterized in that, Including components in the following weight parts: Polyamide 66: 0 - 80 parts; The composite antioxidant composition according to any one of claims 1 - 3: 20 - 100 parts.

6. The preparation method of the composite antioxidant masterbatch for polyamide 66 according to claim 5, characterized in that, Including the following steps: After mixing the composite antioxidant composition and polyamide 66, extrude and pelletize to obtain a composite antioxidant masterbatch for polyamide 66; The temperature of the extrusion pelletization is 50 - 150 °C.

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