Compound antioxidant composition and its preparation method, compound antioxidant masterbatch for polyamide 66 and its preparation method

Abstract

This application relates to the field of antioxidant technology and specifically discloses a composite antioxidant composition and its preparation method, as well as a composite antioxidant masterbatch for polyamide 66 and its preparation method. The composite antioxidant composition comprises a mixture of 25-50% phenolic antioxidant, 25-50% phosphite antioxidant phosphate complex, 5-15% synergist, 2-12% filler, and 5-15% lubricant. The preparation method comprises stirring and mixing the phenolic antioxidant, phosphite antioxidant phosphate complex, synergist, filler, and lubricant to obtain the composite antioxidant composition. The composite antioxidant composition of the application can effectively capture free radicals, inhibit the occurrence of oxidation reactions, and significantly improve the antioxidant composition's ability to resist yellowing in high-temperature environments.

Description

Technical Field

[0001] The present 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, widely used in the automotive, electronics, textile, and industrial sectors due to its excellent mechanical properties, heat resistance, and chemical resistance. However, PA66 is susceptible to oxidative degradation and yellowing at high temperatures. This yellowing not only affects the appearance of PA66 but also reduces its physical properties and service life. Therefore, improving the anti-yellowing properties of PA66 has become a key research topic in materials science.

[0003] Currently, researchers have explored the effects of different phenolic antioxidants on the antioxidant properties of polyamide 66. The results show that the addition of antioxidants improves the oxidative stability of polyamide 66.

[0004] However, under high temperature conditions, the migration speed of antioxidants is too fast, so polyamide 66 will still turn yellow after being used under high temperature conditions for a period of time. Summary of the Invention

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

[0006] In a first aspect, the present application provides a composite antioxidant composition, which adopts the following technical solution:

[0007] A composite antioxidant composition, consisting of the following components in percentage by weight:

[0008] Phenolic antioxidants 25-50%;

[0009] Phosphite antioxidant phosphate complex 25-50%;

[0010] Synergist 5-15%;

[0011] Filler 2-12%;

[0012] Lubricant 5-15%;

[0013] The phenolic antioxidant includes one or more of Irganox 1010, Irganox 1076, Irganox 1098, Irganox 1330, Irganox 3125, Irganox 3114, Irganox 245, Lowinox 1790 and Sumilizer GA80;

[0014] 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.

[0015] Under high temperature conditions, the molecular chains of polymers are easily broken, generating free radicals, which in turn trigger oxidation reactions. By adopting the above technical solution, the above-mentioned types of phenolic antioxidants have excellent thermal stability and can effectively inhibit the generation of free radicals at high temperatures; the above-mentioned types of phosphite antioxidant phosphate complexes contain a secondary antioxidant that decomposes peroxides, which can decompose peroxide radicals at high temperatures and protect the color of the material. Therefore, the above-mentioned types of phenolic antioxidants and phosphite antioxidant phosphate complexes are compounded in a certain ratio. The resulting 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 life of the polymer.

[0016] Preferably, the phenolic antioxidant includes Irganox 1098 and Sumilizer GA80; and the phosphite antioxidant phosphate complex includes Doverphos S-9228 and BRUGGOLEN H10.

[0017] Preferably, the phenolic antioxidant is composed of Irganox 1098 and Sumilizer GA80 mixed in a weight ratio of 1: (1-3.52).

[0018] Preferably, the phosphite antioxidant phosphate complex is composed of a mixture of Doverphos S-9228 and BRUGGOLEN H10, and the weight ratio of Irganox 1098, Doverphos S-9228 and BRUGGOLEN H10 is 1:2:(1-2).

[0019] By adopting this technical solution, Irganox 1098 and Doverphos S-9228 have high molecular weights and are resistant to volatilization. Sumilizer GA-80 provides continuous antioxidant protection even at high temperatures. BRUGGOLEN H10, a phosphorus-containing inorganic salt, possesses very strong reducing properties, which impart excellent anti-yellowing properties. Therefore, the antioxidant composition produced by combining these antioxidants exhibits excellent anti-yellowing properties even at high temperatures.

[0020] Preferably, the synergist is stearate, hydrotalcite or zinc oxide.

[0021] Preferably, the stearate includes zinc stearate, calcium stearate, magnesium stearate or aluminum stearate.

[0022] Preferably, the stearate is calcium stearate or magnesium stearate.

[0023] By adopting the above technical solution, the use of the synergist enables the antioxidant composition to more effectively inhibit the oxidation reaction at high temperature, which is beneficial to improving the yellowing phenomenon of the polymer and extending the service life of the polymer.

[0024] Preferably, the filler includes nano-silicon dioxide, nano-silicon nitride, nano-aluminum oxide, nano-calcium carbonate, nano-titanium dioxide or nano-clay.

[0025] Preferably, the filler is nano-silicon dioxide.

[0026] By adopting the above technical solution and adding nano-scale fillers, the dispersibility of the antioxidant in the polymer is improved, which is beneficial to improving the mechanical properties and anti-yellowing properties of the polymer.

[0027] Preferably, the lubricant comprises polyethylene wax, amide wax or paraffin wax.

[0028] Preferably, the lubricant is amide wax.

[0029] Preferably, the amide wax is ethylene bisstearamide.

[0030] By adopting the above technical solution, adding the above-mentioned type of lubricant 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, thereby reducing the risk of oxidation caused by shear during processing.

[0031] In a second aspect, the present application provides a method for preparing a composite antioxidant composition, which adopts the following technical solution:

[0032] A method for preparing a composite antioxidant composition comprises the following steps:

[0033] The phenolic antioxidant, the phosphite antioxidant phosphate complex, the synergist, the filler and the lubricant are stirred and mixed to obtain a composite antioxidant composition.

[0034] By adopting the above technical solution, the present application only needs to simply mix the raw materials to obtain the composite antioxidant composition. Therefore, the preparation method of the present application has simple operation steps and is suitable for large-scale production.

[0035] In a third aspect, the present application provides a composite antioxidant masterbatch for polyamide 66, which adopts the following technical solution:

[0036] A composite antioxidant masterbatch for polyamide 66, comprising the following components in parts by weight:

[0037] Polyamide 66 0-80 parts;

[0038] 20 to 100 parts of the above composite antioxidant composition.

[0039] By adopting the above technical solution, the composite antioxidant masterbatch for polyamide 66 of the present application can have a composite antioxidant composition content adjusted between 20% and 100%, which is much higher than the content of commercially available antioxidant masterbatch and has a wider commercial application value.

[0040] In a fourth aspect, the present application provides a method for preparing a composite antioxidant masterbatch for polyamide 66, using the following technical solution:

[0041] A method for preparing a composite antioxidant masterbatch for polyamide 66 comprises the following steps:

[0042] The composite antioxidant composition and polyamide 66 are mixed, and then extruded and granulated to obtain a composite antioxidant masterbatch for polyamide 66;

[0043] The temperature of the extrusion granulation is 50-150°C.

[0044] By adopting the above technical solution, on the one hand, the composite antioxidant composition and polyamide 66 are simply mixed and then extruded and granulated to obtain a masterbatch. The preparation method is simple and suitable for large-scale production.

[0045] On the other hand, the melting point of the lubricant is relatively low. By compounding the synergist and lubricant, the temperature of the extrusion granulation can be reduced to 50-145°C. Compared with the extrusion granulation temperature under high temperature conditions in the related art, the present application reduces the temperature of the extrusion granulation, effectively improving the activity of the antioxidant composition during high-temperature extrusion / injection molding, as well as its thermal stability when used in high-temperature environments.

[0046] Furthermore, in the preparation of composite antioxidant masterbatches for polyamide 66, 15-20% of the components in the composite antioxidant composition can be melted, and then compounded with a specific lubricant, the composition possesses excellent processing properties. Therefore, even when the composite antioxidant composition content is 100%, it can be extruded and granulated to form composite antioxidant masterbatches with smooth surfaces, thus having a wide range of applications.

[0047] In summary, this application has the following beneficial effects:

[0048] 1. Since the present application adopts 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 anti-yellowing performance of the antioxidant composition in a high-temperature environment; at the same time, BRUGGOLEN_H10 has a higher phosphorus content and stronger reducing property. It has excellent short-term high-temperature anti-yellowing performance in the extrusion and injection molding process, aging at 200°C for half an hour, etc.; compared with Doverphos S-9228, BRUGGOLEN_H10 tends to have short-term high-temperature anti-yellowing performance. 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 balanced, and has better protection against yellowing during the processing at 280°C, and also has better protection against yellowing during long-term heat aging in the later period; but using Doverphos The combination of S-9228 and BRUGGOLEN_H10 exhibits a synergistic effect, balancing color protection during short-term processing with long-term thermal aging. The resulting composite antioxidant composition, after high-temperature granulation and multiple injection molding, exhibits excellent anti-yellowing properties even after aging at 90°C for three days under low- to medium-temperature aging conditions.

[0049] 2. The composite antioxidant masterbatch for polyamide 66 of the present application has an antioxidant content of up to 20-100%, and has a wide commercial value;

[0050] 3. The preparation method of the composite antioxidant masterbatch for polyamide 66 in the present application reduces the temperature of extrusion granulation and reduces the thermal aging of polyamide 66 in the masterbatch under high temperature conditions by adopting a compound of a synergist, a lubricant, a phenolic antioxidant and a phosphite antioxidant phosphate complex, thereby improving the anti-yellowing performance of the composite antioxidant masterbatch for polyamide 66 under high temperature environment. DETAILED DESCRIPTION

[0051] The present application is further described in detail below with reference to the embodiments.

[0052] Example 1

[0053] A composite antioxidant composition, the components and their corresponding weights (kg) are shown in the following table.

[0054]

[0055] The preparation method of the composite antioxidant composition comprises the following steps:

[0056] The phenolic antioxidant, the phosphite antioxidant phosphate complex, the synergist, the filler and the lubricant were stirred and mixed at 300 r / min for 10 minutes to obtain a composite antioxidant composition.

[0057] Examples 2 to 7

[0058] A composite antioxidant composition, which is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0059]

[0060] Examples 8 to 10

[0061] A composite antioxidant composition, which is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0062]

[0063] Example 11

[0064] A composite antioxidant composition, which is different from Example 1 in that the synergist is hydrotalcite and the lubricant is polyethylene wax AC 540A.

[0065] Comparative Examples 1-2

[0066] A composite antioxidant composition, which is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0067]

[0068] Comparative Examples 3-4

[0069] A composite antioxidant composition masterbatch, the components and their corresponding weight (kg) are shown in the following table.

[0070]

[0071] Application Example 1

[0072] A composite antioxidant masterbatch for polyamide 66, the components and their corresponding weights are shown in the following table.

[0073]

[0074] The preparation method of the composite antioxidant masterbatch for polyamide 66 comprises the following steps:

[0075] After polyamide 66 was dried at 50°C for 6 hours, polyamide 66 was added to a twin-screw extruder as a side feed, and the composite antioxidant composition was added to the twin-screw extruder as a main feed. Then, the mixture was blended, extruded and granulated at a main engine speed of 15 Hz and a feeding rate of 10 Hz to obtain a composite antioxidant masterbatch for polyamide 66.

[0076] In the application example of this application, the twin-screw extruder, model HK-26, was purchased from Nanjing Keya Twin-Screw Extruder;

[0077] During extrusion granulation, the temperature of zone 1 in the twin-screw extruder is 90°C, the temperature of zone 2 is 100°C, the temperatures of zones 3 to 8 are all 120°C, and the head temperature is 120°C.

[0078] Application Examples 2-10

[0079] A composite antioxidant masterbatch for polyamide 66 is different from Application Example 1 in that the components and their corresponding weights are shown in the following table.

[0080]

[0081] Application Example 11

[0082] A composite antioxidant masterbatch for polyamide 66, which is different from Application Example 1 in that the composite antioxidant composition adopts the composite antioxidant composition prepared in Example 11.

[0083] In the above-mentioned preparation method of composite antioxidant masterbatch for polyamide 66, during extrusion granulation, the temperature of zone 1 in the twin-screw extruder is 80°C, the temperature of zone 2 is 100°C, the temperatures of zones 3 to 8 are all 110°C, and the head temperature is 110°C.

[0084] Comparative Application Examples 1 to 4

[0085] A composite antioxidant masterbatch, which is different from Application Example 1 in that the components and their corresponding weights are shown in the following table.

[0086]

[0087] Anti-yellowing performance test:

[0088] The composite antioxidant masterbatch for polyamide 66 prepared in Application Examples 1 to 11 and the composite antioxidant masterbatch prepared in Comparative Application Examples 1 to 4 were mixed with polyamide 66 and granulated, and then injection molded into samples. The samples were then tested for anti-yellowing performance. The specific steps are as follows:

[0089] (1) The formula of the sample and its corresponding dosage are shown in the following table.

[0090]

[0091] The preparation method of the above sample is as follows:

[0092] (1) Preparation of resin particles

[0093] After polyamide 66 was dried at 85°C for 8 hours, it was mixed with masterbatches of different formulations in a screw extruder, extruded and granulated three times, and then pelletized using a pelletizer to obtain blank resin particles of the first extrusion granulation, blank resin particles of the third extrusion granulation, antioxidant resin particles of the first extrusion granulation, antioxidant resin particles of the third extrusion granulation, comparison antioxidant resin particles of the first extrusion granulation, and comparison antioxidant resin particles of the third extrusion granulation, respectively.

[0094] During the extrusion granulation, the temperature of zone 1 in the twin-screw extruder was 230°C, the temperature of zone 2 was 260°C, the temperatures of zones 3 to 8 were all 270°C, and the die head temperature was 275°C.

[0095] In this application, blank resin pellets were first produced. After extrusion of each antioxidant resin pellet or control antioxidant resin pellet, the blank resin pellets were used to clean the screw extruder and pelletizer. Approximately 1000g of pellets were collected from the middle section of the first and third extrusions of each antioxidant resin pellet to serve as the raw material for the antioxidant resin sample pellets.

[0096] (2) Preparation of samples

[0097] The blank resin particles extruded and granulated for the first time and the blank resin particles extruded and granulated for the third time were dried at 85°C for 8 hours, and then added to the injection molding machine respectively for injection molding into 80mm*60mm*2mm antioxidant resin samples. After each sample was continuously injected for 10 molds, sampling was started to obtain the blank resin samples extruded for the first time and the blank resin samples extruded for the third time.

[0098] The antioxidant resin particles extruded and granulated for the first time and the antioxidant resin particles extruded and granulated for the third time were dried at 85°C for 8 hours, and then added to the injection molding machine respectively for injection molding into 80mm*60mm*2mm antioxidant resin samples. After each sample was continuously injected for 10 molds, sampling was started to obtain the antioxidant resin sample extruded for the first time and the antioxidant resin sample extruded for the third time.

[0099] The comparative antioxidant resin particles extruded and granulated for the first time and the comparative antioxidant resin particles extruded and granulated for the third time were dried at 85°C for 8 hours, and then added to the injection molding machine respectively for injection molding into 80mm*60mm*2mm antioxidant resin samples. After each sample was continuously injected for 10 molds, sampling was started to obtain the comparative antioxidant resin sample extruded and granulated for the first time and the comparative antioxidant resin sample extruded and granulated for the third time, respectively.

[0100] Injection molding machine, model MA860 / 280GII, purchased from Haitian;

[0101] During the above injection molding process, the temperature of the first zone of the injection molding machine was 270°C, the temperature of the second zone was 265°C, the temperature of the third zone was 260°C, and the temperature of the fourth zone was 220°C.

[0102] (3) Sample testing

[0103] According to ASTM E313-20, the YI values (yellowness index) of the antioxidant resin sample extruded for the first time, the antioxidant resin sample extruded for the third time, the comparative antioxidant resin sample extruded for the first time, the comparative antioxidant resin sample extruded for the third time, the blank resin sample extruded for the first time, and the blank resin sample extruded for the third time were tested and recorded as the YI value of the first extrusion and the YI value of the third extrusion, respectively.

[0104] According to ASTM E313-20, the first extruded antioxidant resin sample, the first extruded comparative antioxidant resin sample, and the blank resin sample were aged at 90°C for 3 days. The YI values of each day were measured and recorded as the YI value after 90°C aging. Then, ΔYI was calculated using the following formula:

[0105] ΔYI = YI value after aging at 90°C - YI value of the first extrusion.

[0106] (4) Test data

[0107] The test data of the sample three times of extrusion are shown in the following table.

[0108]

[0109] Data analysis of the table above indicates that the YI values of the first and third extrusions of Comparative Samples 1 to 4 are significantly higher than those of Samples 1 to 10. This indicates that the use of the composite antioxidant masterbatch for polyamide 66 prepared in Application Examples 1 to 10 in the total raw materials used to prepare the samples of this application can improve the anti-yellowing performance of the samples after multiple extrusions.

[0110] Compared to Sample 1, the YI values of the first and third extrusions of Comparative Samples 1 and 2 increased significantly. This indicates that, in the total raw materials used to prepare the samples of this application, the composite antioxidant masterbatch for polyamide 66, when prepared by compounding a specific type of phenolic antioxidant and a phosphite antioxidant phosphate complex, can improve the anti-yellowing performance of the samples.

[0111] Compared with sample 1, the YI values of the first extrusion and the third extrusion of comparative samples 3 and 4 increased significantly. This shows that the anti-yellowing performance of the sample can be improved by controlling the compounding ratio of the phenolic antioxidant and the phosphite antioxidant phosphate complex in the total raw materials used to prepare the sample of the present application.

[0112] Compared to Sample 1, the YI values of Sample 8 during the first and third extrusions were significantly lower. This indicates that, in the total raw materials used to prepare the samples of this application, the phosphite antioxidant phosphate complex in the composite antioxidant masterbatch for polyamide 66, which is composed of a mixture of Doverphos S-9228 and BRUGGOLEN H10, and the phenolic antioxidant, which is composed of a mixture of Irganox 1098 and Sumilizer GA80, can improve the anti-yellowing performance of the samples.

[0113] Compared with sample 1, the YI values of the first extrusion and the third extrusion of samples 9 and 10 are significantly lower. This shows that when the total raw materials used to prepare the samples of this application are mixed with Irganox 1098, Doverphos S-9228, and BRUGGOLEN H10 in the composite antioxidant masterbatch for polyamide 66 at a weight ratio of 1:2:(1-2) in the total raw materials used to prepare the samples, the samples have higher anti-yellowing performance.

[0114] The test data of the samples after aging at 90℃ for 3 days are shown in the following table.

[0115]

[0116] By analyzing the data in the table above, it can be seen that the ΔYI values of samples 1 to 4 after aging for one day, two days, and three days are significantly increased compared to samples 1 to 11. This indicates that the use of the composite antioxidant masterbatch for polyamide 66 prepared in Application Examples 1 to 10 in the total raw materials used to prepare the samples of this application can improve the anti-yellowing performance of the samples after aging for three days at 90°C.

[0117] Compared to Sample 1, the ΔYI values of Sample 8 after aging for 1 day, 2 days, and 3 days were significantly lower. This indicates that, among the total raw materials used to prepare the samples of this application, the phosphite antioxidant phosphate complex in the composite antioxidant masterbatch for polyamide 66, which is composed of a mixture of Doverphos S-9228 and BRUGGOLEN H10, and the phenolic antioxidant, which is composed of a mixture of Irganox 1098 and Sumilizer GA80, can improve the anti-yellowing performance of the samples under high temperature conditions.

[0118] Compared to Sample 1, the ΔYI values of Samples 9 and 10 after aging for 1 day, 2 days, and 3 days were significantly lower. This indicates that when the total raw materials used to prepare the samples of this application are mixed with Irganox 1098, Doverphos S-9228, and BRUGGOLEN H10 in the composite antioxidant masterbatch for polyamide 66 at a weight ratio of 1:2:(1-2), the samples have high anti-yellowing performance under high temperature conditions.

[0119] Compared to Sample 1, the ΔYI values of Sample 11 after aging for 1 day, 2 days, and 3 days increased slightly. This indicates that, among the total raw materials used to prepare the samples of this application, the stearate used in the composite antioxidant masterbatch for polyamide 66 is calcium stearate, and the amide wax is ethylene bisstearamide, which can improve the anti-yellowing performance of the samples under high temperature conditions.

[0120] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A composite antioxidant composition, characterized in that It is composed of the following components in percentage by weight: Phenolic antioxidants 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, characterized in that 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 silicon dioxide, nano silicon nitride, nano aluminum oxide, nano calcium carbonate, nano titanium dioxide or nano clay.

4. The method for preparing the composite antioxidant composition according to any one of claims 1 to 3, characterized in that: The following steps are involved: The phenolic antioxidant, the phosphite antioxidant phosphate complex, the synergist, the filler and the lubricant are stirred and mixed to obtain a composite antioxidant composition.

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

6. The method for preparing a composite antioxidant masterbatch for polyamide 66 according to claim 5, characterized in that: The following steps are involved: The composite antioxidant composition and polyamide 66 are mixed, and then extruded and granulated to obtain a composite antioxidant masterbatch for polyamide 66; The temperature of the extrusion granulation is 50-150°C.

Images