A method of preparing an ultra-high molecular weight polyethylene composition

Abstract

The application discloses a preparation method of an ultrahigh molecular weight polyethylene composition, which comprises the following steps: 1) uniformly mixing ultrahigh molecular weight polyethylene resin, hindered amine stabilizer and part of an antioxidant to obtain a premixed composition; and 2) adding the rest of the antioxidant and peroxide to the premixed composition after irradiation of the premixed composition by high-energy electron beams or a cobalt source at a dose of 15-50 Kgy to obtain the ultrahigh molecular weight polyethylene composition. Compared with the prior art, the application reduces the peroxide addition amount in the ultrahigh molecular weight polyethylene composition by irradiation modification, improves crosslinking efficiency, avoids the adverse effects caused by excessively high peroxide addition amount, and improves the wear resistance and heat resistance of the ultrahigh molecular weight polyethylene composition. The ultrahigh molecular weight polyethylene composition can be used to manufacture wear-resistant and pressure-resistant pipes and wear-resistant plates with high heat resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymers, and particularly relates to a preparation method of an ultra-high molecular weight polyethylene composition. BACKGROUND

[0002] Ultra high molecular weight polyethylene (UHMWPE) is a linear structure thermoplastic engineering plastic, which has good impact resistance, strong wear resistance, good corrosion resistance and self-lubricating property, and is widely used in the fields of transportation, agriculture, chemical industry, petroleum, machinery, construction, papermaking, packaging, textile, food, electricity, medical treatment and sports. At present, the largest consumption field of UHMWPE in China is to produce plates, profiles and pipes. However, poor creep resistance and low heat distortion temperature greatly limit the application of UHMWPE. Since the product based on UHMWPE is prone to deformation, especially under high temperature or stress conditions, the creep resistance is poorer. Therefore, in order to broaden the application range of UHMWPE, it is very important to improve the thermal stability and creep resistance of UHMWPE.

[0003] The slow migration of molecular chains is an intrinsic factor of poor creep resistance of UHMWPE, and reducing the movement of molecular chains can bring changes in other properties, such as improving the thermal stability of UHMWPE. The traditional method is to enhance the intermolecular force through particle filling and blending modification, and then to improve the creep resistance of UHMWPE, but the effect is not good. Moreover, because the viscosity of UHMWPE itself is very large, the particle filling and blending modification increase the difficulty of the processing technology of UHMWPE. At present, radiation crosslinking modification and chemical crosslinking modification (mainly peroxide crosslinking modification) are two main means of modifying UHMWPE through crosslinking. However, the chemical crosslinking method has the problems of high content of crosslinking agent peroxide, and then produces volatile substances and odors and other adverse effects. Radiation crosslinking is considered to be a simple and effective method to improve the performance of various polymers. Under normal conditions, radiation can cause crosslinking of polyethylene resin and degradation of polypropylene resin. However, using high radiation dose of gamma rays or electron beam radiation on the surface of PE-UHMW will cause oxidation, aging and a large number of free radicals, which seriously affect the mechanical properties, stability and wear resistance of the product. Using low-dose radiation will cause the crosslinking density to decrease synchronously, and the expected modification effect cannot be achieved.

[0004] As disclosed in Chinese patent document CN111135343A, a high-crosslinking high-antioxidant-doped artificial joint prosthesis material and a preparation method thereof are disclosed. An organic peroxide is used as a chemical crosslinking agent, and the content of the organic peroxide crosslinking agent in the total mass of the polyphenol antioxidant, the ultra-high molecular weight polyethylene, and the organic peroxide crosslinking agent is 0.5% to 3%. The crosslinking density of the high-content polyphenol antioxidant stable ultra-high molecular weight polyethylene material is improved, and the higher polyphenol content makes the material have better oxidation stability.

[0005] Chinese patent document CN115746344A discloses an ultra-high molecular weight polyethylene product and a preparation method and application thereof. The ultra-high molecular weight polyethylene and the functional masterbatch are mixed to obtain a mixture, and the mixture is hot-pressed under oscillation to obtain the ultra-high molecular weight polyethylene product. The functional masterbatch contains 100 parts by weight of polyethylene, 0.3 to 5 parts by weight of a crosslinking agent, and 2 to 30 parts by weight of a crosslinking aid.

[0006] In order to improve the crosslinking efficiency, Chinese patent document CN1749303A uses infrared radiation special equipment to irradiate and crosslink a polyethylene resin composition added with a peroxide crosslinking agent, an auxiliary crosslinking agent, an antioxidant, and a lubricant to form a crosslinked polyethylene pipe and cable product.

[0007] Chinese patent document CN101848968A discloses introducing a hindered amine light stabilizer (HALS) into an (U)HMWPE resin, and crosslinking the (U)HMWPE during or after molding of the (U)HMWPE resin. The HALS is introduced into the (U)HMWPE resin by mixing the HALS with the (U)HMWPE resin or (U)HMWPE melt, or by immersing the (U)HMWPE resin with a HALS solution, or by spraying a HALS solution onto the (U)HMWPE resin, or by adding the HALS to the (U)HMWPE melt. An initiator such as a peroxide can also be added, and an activity aid can be added optionally. Then the (U)HMWPE resin containing the HALS is molded to obtain a product. Finally, the product is crosslinked and sterilized by gamma radiation or electron beam radiation to obtain an artificial medical implant. The disclosed technology prepares an artificial medical implant by irradiation crosslinking, which is not suitable for large pipe and plate products, and there is still a need for an ultra-high molecular weight polyethylene composition that can be directly processed and molded on existing equipment.

[0008] In summary, the existing chemical crosslinking method has a high content of peroxide crosslinking agent, which produces volatile substances and odors. The irradiation crosslinking method for modifying ultra-high molecular weight polyethylene requires irradiation of the product, which is not suitable for large pipe and plate products. SUMMARY

[0009] In view of the problems existing in the prior art and the direction for improvement, the application provides a preparation method of an ultrahigh molecular weight polyethylene composition, which comprises the following steps: firstly, mixing ultrahigh molecular weight polyethylene resin, part of an antioxidant and a hindered amine stabilizer, then irradiating under a specific irradiation dose to obtain a composition easy to be chemically crosslinked, and finally adding the remaining antioxidant and peroxide to perform chemical crosslinking, so that the amount of peroxide can be significantly reduced, and the problems of high content of crosslinking agent peroxide, easy generation of volatile substances and odor and the like in the existing chemical crosslinking mode are overcome.

[0010] To achieve the above object, the application provides the following technical scheme.

[0011] A preparation method of an ultrahigh molecular weight polyethylene composition, characterized in that the method comprises the following steps:

[0012] 1) mixing ultrahigh molecular weight polyethylene resin, a hindered amine stabilizer and part of an antioxidant uniformly to obtain a premixed composition;

[0013] 2) adding the remaining antioxidant and peroxide to the premixed composition after irradiation by high-energy electron beam or a cobalt source at 15-50 Kgy to obtain the ultrahigh molecular weight polyethylene composition.

[0014] Optionally, in the preparation method of the ultrahigh molecular weight polyethylene composition recommended by the application, the irradiation dose is 20-40 KGy.

[0015] Optionally, in the preparation method of the ultrahigh molecular weight polyethylene composition provided by the application, the mass ratio of the antioxidant in step 1) to the antioxidant in step 2) is 1:0.35-4; preferably 1:1-2.5.

[0016] Optionally, in the preparation method of the ultrahigh molecular weight polyethylene composition provided by the application, the hindered amine stabilizer is 0.01-0.05 parts by weight, the antioxidant is 0.4-0.8 parts by weight and the peroxide is 0.03-0.2 parts by weight, based on 100 parts by weight of the ultrahigh molecular weight polyethylene resin.

[0017] Optionally, in the preparation method of the super high molecular weight polyethylene composition recommended by the present application, the super high molecular weight polyethylene resin can be a commercially available product or can be polymerized from ethylene; the polymerization process is similar to that of common high density polyethylene, and both are polymerized from ethylene under certain conditions using Z-N catalyst. The third generation Z-N catalyst is mainly used in the domestic super high molecular weight polyethylene. The super high molecular weight polyethylene is obtained by adding the catalyst and ethylene into a reaction kettle and then polymerizing. The polymerization process is divided into continuous polymerization process and batch polymerization process according to whether the reaction is continuous. At present, most of the industrial devices for producing super high molecular weight polyethylene adopt slurry polymerization, and the slurry process mainly includes stirred tank process and loop process.

[0018] The method for producing the super high molecular weight polyethylene resin by using the conventional slurry process is as follows: high purity ethylene is subjected to coordination polymerization in an alkane solvent under the initiation of Z-N catalyst and alkyl aluminum cocatalyst at 0.3-0.8 MPa and 65-85°C to obtain the super high molecular weight polyethylene resin.

[0019] Optionally, in the preparation method of the super high molecular weight polyethylene composition recommended by the present application, the super high molecular weight polyethylene resin has a viscosity average molecular weight of 1.5-5 million, an apparent density of 0.35-0.50 g / cm 3 , and an average particle size of 70-300 microns.

[0020] Optionally, in the preparation method of the ultra-high molecular weight polyethylene composition recommended by the present application, the hindered amine stabilizer is selected from any one of bis(2,2,6,6,-tetramethyl-4-piperidyl) sebacate (GW-770), bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate (GW-123), 2,2,6,6-tetramethyl-4-piperidyl stearate (GW-3853), poly{(6-morpholino-5-triazine-2,4-diyl)(2,2,6,6-tetramethylpiperidyl) iminyl hexamethylene [(2,2,6,6-tetramethylpiperidyl)-iminyl]} (GW-3346), poly{[6-[(1,1,3,3-tetramethylbutyl)amino]]-1,3,5-triazine-2,4-[(2,2,6,6,-tetramethyl-piperidyl) imino]-1,6-hexanediy [(2,2,6,6-tetramethyl-4-piperidyl) imino]} (GW-944), poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol) succinate (GW-622), high molecular weight triazine-piperidine condensate (GW-119), polymer of the reaction product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine with 2,4,6-trichloro-1,3,5-triazine, N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, polymer containing polymeric segments of 2,2,6,6-tetramethylpiperidinolyl-4-methacrylate (TMPM) and / or 1,2,2,6,6-pentamethylpiperidinolyl-4-methacrylate (PMPM);

[0021] The polymer containing polymeric segments of 2,2,6,6-tetramethylpiperidinolyl-4-methacrylate (TMPM) and / or 1,2,2,6,6-pentamethylpiperidinolyl-4-methacrylate (PMPM) refers to a polymer containing -(TMPM)m- structural units and / or -(PMPM)m- structural units, m is 4-100, and the specific TMPM and PMPM homo- or co-polymerization method can use conventional methods in the industry, such as mixing initiator, monomer TMPM and / or PMPM, solvent, and then polymerizing under certain conditions to obtain the target product.

[0022] Optionally, in the preparation method of the ultra-high molecular weight polyethylene composition, the antioxidant comprises a primary antioxidant, and the primary antioxidant is a phenolic antioxidant; preferably, the phenolic antioxidant is at least one selected from 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl) benzene (antioxidant 330), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester (antioxidant 1076), 4,4'-thiobis(6-tert-butyl-3-methylphenol) (antioxidant 300), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (antioxidant 1010).

[0023] Optionally, in the preparation method of the ultra-high molecular weight polyethylene composition, the antioxidant further comprises a secondary antioxidant, and the secondary antioxidant is at least one selected from phosphite antioxidants (such as tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), etc.), hydrazide antioxidants (such as N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazide (antioxidant 1024), etc.), and thioester antioxidants (such as thiodipropionic acid ester, etc.); preferably, the mass ratio of the primary antioxidant to the secondary antioxidant is 2-4:1.

[0024] Optionally, in the preparation method of the ultra-high molecular weight polyethylene composition, the peroxide is at least one selected from tert-butyl peroxyisopropyl carbonate, tert-butyl peroxylaurate, 2,5-dimethyl-2,5-di(benzoylperoxy) hexane, tert-butyl peroxyacetate, di-tert-butyl diperoxyphthalate, tert-butyl peroxymaleic acid, cyclohexanone peroxide, tert-butyl peroxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane, tert-butyl cumyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane-3, and α,α'-bis-tert-butylperoxy-1,4-diisopropylbenzene.

[0025] Optionally, in the preparation method of the ultra-high molecular weight polyethylene composition, the peroxide is generally added to the premixed composition after irradiation in a liquid state, for example, the peroxide can be added to the premixed composition after irradiation by spraying, dipping, or splashing; the peroxide and the remaining antioxidant cannot be added together at the same time, but the order of addition is not limited.

[0026] Optionally, the application further provides a use of the ultra-high molecular weight polyethylene composition prepared by the above preparation method in the preparation of pipe or plate materials; that is, the ultra-high molecular weight polyethylene composition is used to process wear-resistant pipe or plate materials, and if necessary, fillers such as carbon black can be added during the preparation of the pipe.

[0027] Specifically, the pipe or pipe material can be prepared by using existing equipment and combining existing process parameters. For example, when preparing wear-resistant plate material, the following method can be used:

[0028] The ultrahigh molecular weight polyethylene composition is added to a mold (an existing grinding tool can be used, for example, the mold cavity has a length, width and height of 200 mm), and then the mold is placed in a flat vulcanizing machine that has been preheated to 210-230°C. The plate material is prepared by pressing at a temperature of 210-230°C and a pressure of 10-20 MPa for 4-7 hours, then maintaining the pressure at 10-20 MPa, cooling the flat vulcanizing machine to below 40°C, demolding and taking out the plate material, to obtain an ultrahigh molecular weight polyethylene wear-resistant plate material of a corresponding thickness. The mass of the ultrahigh molecular weight polyethylene composition can be added according to the required thickness.

[0029] For example, when preparing pipe material, the following pipe extrusion conditions can be used: heating temperature of 220-240°C, die extrusion temperature of 230-250°C, main screw rotation speed of 110-140 r / min, feeding rotation speed of 150-200 r / min, and pulling speed of 0.5-1.0 m / min to obtain pipe material of a corresponding specification. The mass of the ultrahigh molecular weight polyethylene composition can be added according to the actual required specification of the pipe material.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] 1. The preparation method of the ultrahigh molecular weight polyethylene composition provided by the present application can reduce the amount of peroxide used in chemical crosslinking by irradiation modification, improve crosslinking efficiency, avoid the adverse effects of excessive peroxide addition (overcome the problem of high volatile content in crosslinked materials in the existing chemical crosslinking method), and improve the wear resistance and heat resistance of the ultrahigh molecular weight polyethylene composition. The ultrahigh molecular weight polyethylene composition prepared by this method can be processed into pipe material and plate material using existing pipe and plate production equipment, resulting in pipe material and plate material with excellent appearance and performance, without increasing the equipment investment of manufacturers. Moreover, the appearance of the pipe material, plate material and other products will not yellow after long-term storage.

[0032] 2、The preparation method of the ultra-high molecular weight polyethylene composition provided by the application can further improve the wear resistance and heat resistance of the ultra-high molecular weight polyethylene composition by further limiting the proportion of the antioxidant added in steps 1) and 2) and the amount of each component. DETAILED DESCRIPTION

[0033] The application will be specifically described below through examples. It is necessary to point out here that the following examples are only used to further illustrate the application and cannot be understood as limiting the protection scope of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content of the application.

[0034] If the specific experimental steps or conditions are not specified in the examples and comparative examples, the operations or conditions can be performed according to the conventional experimental steps described in the literature in the field. If the reagents or instruments used are not specified by the manufacturer, they are all conventional reagent products that can be obtained by purchase.

[0035] The intrinsic viscosity of the ultra-high molecular weight polyethylene resin is tested according to the provisions of GB / T 1632.3, and then the viscosity average molecular weight is calculated according to formula (1).

[0036] [M]=5.37×10 4 [η] 1.37 …………………………………(1)

[0037] The apparent density of the ultra-high molecular weight polyethylene resin is determined according to GB / T 1636, and the average particle size is obtained by laser particle size instrument D50.

[0038] The yellow index refers to the degree of deviation of a plastic product from white, and a positive value indicates that the sample presents yellow, and a negative value indicates that the sample presents blue. The yellow index can directly reflect the color condition of the product and is used to evaluate its aging performance. The yellow index is determined according to ASTM E313.

[0039] The wear resistance is tested according to the provisions of SH / T 1818-2017, and the load deformation temperature is tested according to GB / T1634.2.

[0040] Example 1

[0041] The embodiment provides a preparation method of an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0042] 1) Preparation of hindered amine stabilizer poly(2,2,6,6-tetramethylpiperidinyl-4- methyl methacrylate): Add azobisisobutyronitrile, 2,2,6,6-tetramethylpiperidinyl-4- methyl methacrylate and acetone into a polymerization tube in turn, mix uniformly, repeat the process of cooling with liquid nitrogen, vacuumizing, passing nitrogen and thawing for 3 times, vacuum seal the tube, and stir at 76°C for 4h. The crude product is precipitated in n-hexane, and dried to obtain poly(2,2,6,6-tetramethylpiperidinyl-4-methyl methacrylate).

[0043] 2) Mix 100 parts by weight of the ultra-high molecular weight polyethylene resin (viscosity average molecular weight 2 million, apparent density 0.42 g / cm 3 , average particle size 150 microns), 0.01 parts by weight of the above poly(2,2,6,6-tetramethylpiperidinyl-4-methyl methacrylate) and 0.10 parts by weight of antioxidant 1010 uniformly to form a premix composition;

[0044] 3) The premix composition is irradiated by a cobalt source at a dose of 18 kGy to obtain a pre-irradiated composition; 0.12 parts by weight of di-t-butyl peroxide is added to the pre-irradiated composition by spraying, and then mixed uniformly with 0.30 parts by weight of antioxidant 1010 to obtain an ultra-high molecular weight polyethylene composition.

[0045] 4) The ultra-high molecular weight polyethylene composition is processed into a wear-resistant plate, and the specific method is as follows:

[0046] 2650 g of the ultra-high molecular weight polyethylene composition is added into a mold with a cavity of 200 mm in length, width and height, and the mold is placed in a flat curing press which has been preheated to 210°C. The flat curing press is pressed at a temperature of 210°C and a pressure of 10 MPa for 6h, and then the pressure is maintained at 10 MPa. The flat curing press is cooled to below 40°C, and the plate is removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate with a thickness of 70 mm.

[0047] Example 2

[0048] This example provides a method for preparing an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0049] 1) Hindered amine stabilizer dodecyl poly 1,2,2,6,6-pentamethylpiperidinyl-4- methacrylate is prepared: 2-cyano-2-propyldodecyltrithiocarbonate, dibenzoyl peroxide, 1,2,2,6,6-pentamethylpiperidinyl-4-methacrylate and acetone are added into a polymerization tube in turn, after mixing homogeneously, the mixture is cooled by liquid nitrogen, vacuumed, nitrogen is introduced, and the mixture is thawed, the above process is repeated for 3 times, the tube is sealed under vacuum, and the mixture is stirred at 80°C for 6 hours. The obtained crude product is precipitated in methanol / water (v / v: 1 / 1), and after drying, dodecyl poly 1,2,2,6,6-pentamethylpiperidinyl-4-methacrylate is obtained, wherein the polymerization degree of monomer 1,2,2,6,6-pentamethylpiperidinyl-4-methacrylate is 60.

[0050] 2) 100 parts by weight of the ultra-high molecular weight polyethylene resin (viscosity average molecular weight 1.7 million, apparent density 0.38 g / cm 3 , average particle size 75 microns), 0.03 parts by weight of the above dodecyl poly 1,2,2,6,6-pentamethylpiperidinyl-4-methacrylate and 0.30 parts by weight of antioxidant 1076 are uniformly mixed to form a premixed composition;

[0051] 3) The premixed composition is irradiated by a cobalt source at a dose of 21 kGy to obtain a pre-irradiated composition; the pre-irradiated composition is uniformly mixed with 0.20 parts by weight of antioxidant 1076 to obtain a mixture; then 0.04 parts by weight of t-butyl cumyl peroxide is added to the mixture in an impregnated manner to obtain an ultra-high molecular weight polyethylene composition.

[0052] 4) The ultra-high molecular weight polyethylene composition is processed into a pipe, and the pipe extrusion conditions are as follows: heating temperature is 220°C, die extrusion temperature is 230°C, main screw rotation speed of the extruder is 140 r / min, feeding rotation speed is 190 r / min, and traction speed is 1 m / min to obtain a φ110x10 pipe.

[0053] Example 3

[0054] The present embodiment provides a preparation method of an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0055] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 2.3 million, apparent density 0.48 g / cm 3 , average particle size 89 microns), 0.02 parts by weight of GW-770 and 0.20 parts by weight of antioxidant 300 are uniformly mixed to form a premixed composition;

[0056] 2) The premix composition was irradiated by cobalt source at a dose of 46 kGy to obtain a pre-irradiated composition; the pre-irradiated composition was mixed with 0.40 parts by weight of antioxidant 300 to obtain a mixture, and then 0.19 parts by weight of t-butyl peroxyl laurate was added to the mixture in a spraying manner to obtain an ultra-high molecular weight polyethylene composition.

[0057] 3) The ultra-high molecular weight polyethylene composition was processed into a wear-resistant plate, and the specific method was as follows:

[0058] 2250 g of the ultra-high molecular weight polyethylene composition was added into a mold with a cavity of 200 mm in length, width and height, and the mold was placed in a flat curing press which had been preheated to 220°C; the flat curing press was pressed at a temperature of 220°C and a pressure of 15 MPa for 5 h, and then the pressure was maintained at 15 MPa, and the flat curing press was cooled to below 40°C. The plate was removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate with a thickness of 60 mm.

[0059] Example 4

[0060] The present example provides a preparation method of an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0061] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 2.8 million, apparent density 0.45 g / cm 3 , average particle size 180 microns), 0.03 parts by weight of GW-123 and 0.40 parts by weight of a composite antioxidant (mass ratio of antioxidant 1010 to antioxidant 168 is 2:1) were mixed uniformly to form a premix composition;

[0062] 2) The premix composition was irradiated by high-energy electron beam at a dose of 23 kGy to obtain a pre-irradiated composition; the pre-irradiated composition was mixed with 0.35 parts by weight of antioxidant 300 to obtain a mixture, and then 0.06 parts by weight of α, α'-bis-t-butyl peroxide-1, 4-diisopropylbenzene was added to the mixture in a spraying manner to obtain an ultra-high molecular weight polyethylene composition.

[0063] 3) The ultra-high molecular weight polyethylene composition was processed into a pipe, and the pipe extrusion conditions were as follows: heating temperature was 230°C, die extrusion temperature was 240°C, main screw rotation speed of the extruder was 130 r / min, feeding rotation speed was 170 r / min, and traction speed was 0.5 m / min to obtain a pipe with a specification of φ325x15.

[0064] Example 5

[0065] The present example provides a preparation method of an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0066] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 3.5 million, apparent density 0.40 g / cm3, average particle size 260 microns), 0.05 parts by weight of GW-3853 and 0.15 parts by weight of a composite antioxidant (antioxidant 1010:antioxidant 168 mass ratio 2:1) were mixed uniformly to form a premix composition; 3

[0067] 2) The premix composition was irradiated by high-energy electron beam at a dose of 16 kGy to obtain a pre-irradiated composition; the pre-irradiated composition was mixed uniformly with 0.45 parts by weight of a composite antioxidant (antioxidant 1076:antioxidant 1024 mass ratio 4:1), and then 0.15 parts by weight of di-tert-butyl diperoxyphthalate was added in an impregnation manner to obtain an ultra-high molecular weight polyethylene composition.

[0068] 3) The ultra-high molecular weight polyethylene composition was processed into a pipe, and the pipe extrusion conditions were as follows: heating temperature 235°C, die extrusion temperature 245°C, main screw rotation speed of the extruder 110 r / min, feeding rotation speed 150 r / min, and pulling speed 0.6 m / min to obtain a pipe with a specification of φ273 x 19.

[0069] Example 6

[0070] The present example provides a preparation method of an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0071] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 4.6 million, apparent density 0.44 g / cm3, average particle size 230 microns), 0.04 parts by weight of GW-944 and 0.40 parts by weight of a composite antioxidant (antioxidant 330:thiodipropionic acid mass ratio 3:1) were mixed uniformly to form a premix composition; 3

[0072] 2) The premix composition was irradiated by a cobalt source at a dose of 35 kGy to obtain a pre-irradiated composition; 0.10 parts by weight of dicumyl peroxide was added to the pre-irradiated composition in a spraying manner, and then mixed uniformly with 0.15 parts by weight of a composite antioxidant (antioxidant 330:thiodipropionic acid mass ratio 3:1) to obtain an ultra-high molecular weight polyethylene composition.

[0073] 3) The ultra-high molecular weight polyethylene composition was processed into a wear-resistant plate, and the specific method was as follows:

[0074] ​​A 1500 g of the ultra-high molecular weight polyethylene composition was added into a mold with a cavity of 200 mm in length, width and height, and the mold was placed in a flat curing press which had been preheated to 225°C. The flat curing press was pressed at a temperature of 225°C and a pressure of 17 MPa for 4 hours, after which the pressure was maintained at 17 MPa, and the flat curing press was cooled to below 40°C. The plate was removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate having a thickness of 40 mm.

[0075] Example 7

[0076] The present example provides a method for preparing an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0077] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 2600,000, apparent density 0.41 g / cm 3 , average particle size 200 microns), 0.02 parts by weight of GW-622 and 0.33 parts by weight of a composite antioxidant (antioxidant 1010: antioxidant 1076 in a mass ratio of 1:1) were uniformly mixed to form a premixed composition;

[0078] 2) The premixed composition was irradiated with a cobalt source at a dose of 30 kGy to obtain a pre-irradiated composition; 0.08 parts by weight of t-butyl peroxy isopropyl carbonate was added to the pre-irradiated composition by impregnation, and then 0.25 parts by weight of a composite antioxidant (antioxidant 1010: antioxidant 1076 in a mass ratio of 1:1) was uniformly mixed to obtain an ultra-high molecular weight polyethylene composition.

[0079] 3) 6% of carbon black (based on the mass of the ultra-high molecular weight polyethylene composition, i.e. the amount of carbon black added is 6% of the mass of the ultra-high molecular weight polyethylene composition) was added to the ultra-high molecular weight polyethylene composition, and the composition was processed into a pipe. The pipe extrusion conditions were as follows: heating temperature 225°C, die extrusion temperature 235°C, main screw rotation speed of the extruder 120 r / min, feeding rotation speed 160 r / min, and pulling speed 0.8 m / min to obtain a φ168x12 pipe.

[0080] Example 8

[0081] The present example provides a method for preparing an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0082] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 4000,000, apparent density 0.46 g / cm 3 , average particle size 280 microns), 0.01 parts by weight of GW-3346 and 0.28 parts by weight of a composite antioxidant (antioxidant 1076: antioxidant 330 in a mass ratio of 1:2) were uniformly mixed to form a premixed composition;

[0083] 2) The pre-mixed composition is irradiated by a cobalt source at a dose of 48 kGy to obtain a pre-irradiated composition; 0.13 parts by weight of peroxide (mass ratio of dicumyl peroxide: t-butyl peroxy isopropyl carbonate = 1:1) is added to the pre-irradiated composition by spraying, and then mixed uniformly with 0.32 parts by weight of a composite antioxidant (mass ratio of antioxidant 1076: antioxidant 330 = 1:2) to obtain an ultra-high molecular weight polyethylene composition.

[0084] 3) The ultra-high molecular weight polyethylene composition is processed into a wear-resistant plate, and the specific method is as follows:

[0085] 1880 g of the ultra-high molecular weight polyethylene composition is added to a mold with a cavity length, width and height of 200 mm, and the mold is placed in a flat curing press which has been preheated to 215°C. The flat curing press is pressed at a temperature of 215°C and a pressure of 13 MPa for 7 h, and then the pressure is maintained at 13 MPa. The flat curing press is cooled to below 40°C. The plate is removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate with a thickness of 50 mm.

[0086] Example 9

[0087] The present embodiment provides a method for preparing an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0088] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 4 million, apparent density 0.46 g / cm 3 , average particle size 280 microns), 0.09 parts by weight of GW-3346 and 0.09 parts by weight of a composite antioxidant (mass ratio of antioxidant 1076: antioxidant 330 = 1:2) are mixed uniformly to form a pre-mixed composition;

[0089] 2) The pre-mixed composition is irradiated by a cobalt source at a dose of 48 kGy to obtain a pre-irradiated composition; 0.13 parts by weight of peroxide (mass ratio of dicumyl peroxide: t-butyl peroxy isopropyl carbonate = 1:1) is added to the pre-irradiated composition by spraying, and then mixed uniformly with 0.32 parts by weight of a composite antioxidant (mass ratio of antioxidant 1076: antioxidant 330 = 1:2) to obtain an ultra-high molecular weight polyethylene composition.

[0090] 3) The ultra-high molecular weight polyethylene composition is processed into a wear-resistant plate, and the specific method is as follows:

[0091] The 1880 g of the ultra-high molecular weight polyethylene composition was added into a mold with a cavity of 200 mm in length, width and height, and the mold was placed in a flat vulcanizing machine which had been preheated to 215°C. The ultra-high molecular weight polyethylene composition was pressed at a temperature of 215°C and a pressure of 13 MPa for 7 h, and then the pressure was maintained at 13 MPa. The flat vulcanizing machine was cooled to below 40°C. The plate was removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate with a thickness of 50 mm.

[0092] Example 10

[0093] The present example provides a method for preparing an ultra-high molecular weight polyethylene composition, and the specific steps are as follows:

[0094] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 4 million, apparent density 0.46 g / cm3, average particle size 280 microns), 0.07 parts by weight of GW-3346 and 0.45 parts by weight of a composite antioxidant (mass ratio of antioxidant 1076 to antioxidant 330 is 1:2) were uniformly mixed to form a premixed composition; 3

[0095] 2) The premixed composition was irradiated by a cobalt source at a dose of 48 kGy to obtain a pre-irradiated composition. 0.13 parts by weight of a peroxide (mass ratio of dicumyl peroxide: tert-butyl peroxy isopropyl carbonate is 1:1) was added to the pre-irradiated composition by spraying, and then 0.09 parts by weight of a composite antioxidant (mass ratio of antioxidant 1076: antioxidant 330 is 1:2) was uniformly mixed to obtain an ultra-high molecular weight polyethylene composition.

[0096] 3) The ultra-high molecular weight polyethylene composition was processed into a wear-resistant plate, and the specific method was as follows:

[0097] The 1880 g of the ultra-high molecular weight polyethylene composition was added into a mold with a cavity of 200 mm in length, width and height, and the mold was placed in a flat vulcanizing machine which had been preheated to 215°C. The ultra-high molecular weight polyethylene composition was pressed at a temperature of 215°C and a pressure of 13 MPa for 7 h, and then the pressure was maintained at 13 MPa. The flat vulcanizing machine was cooled to below 40°C. The plate was removed from the mold to obtain an ultra-high molecular weight polyethylene wear-resistant plate with a thickness of 50 mm.

[0098] Comparative Example 1

[0099] The preparation method of the ultra-high molecular weight polyethylene composition provided in the present comparative example is similar to that of Example 1, except that the irradiation step in step 3) is omitted. The specific preparation method of the ultra-high molecular weight polyethylene composition provided in the present comparative example is as follows:

[0100] 1) Hindered amine stabilizer poly 2, 2, 6, 6-tetramethylpiperidyl-4-methacrylate preparation: the same as Example 1.​

[0101] 2) The preparation of the premix composition is the same as in Example 1.

[0102] 3) 0.12 parts by weight of di-t-butyl peroxide is added to the premix composition by spraying, and then mixed uniformly with 0.30 parts by weight of antioxidant 1010 to obtain the ultra-high molecular weight polyethylene composition.

[0103] 4) The ultra-high molecular weight polyethylene composition is processed into wear-resistant plate according to the same method as in Example 1.

[0104] Comparative Example 2

[0105] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that in Example 2, except that the dose of irradiation in step 3) is different. The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0106] 1) Preparation of hindered amine stabilizer dodecyl poly 1,2,2,6,6-, piperidinol-4-methacrylate: the same as in Example 2.

[0107] 2) The preparation of the premix composition is the same as in Example 2.

[0108] 3) The premix composition is irradiated by a cobalt source at a dose of 11 kGy to obtain a pre-irradiated composition; the pre-irradiated composition is mixed uniformly with 0.20 parts by weight of antioxidant 1076 to obtain a mixture; then 0.04 parts by weight of t-butyl cumyl peroxide is added to the mixture by impregnation to obtain the ultra-high molecular weight polyethylene composition.

[0109] 4) The ultra-high molecular weight polyethylene composition is processed into a pipe according to the same method as in Example 2.

[0110] Comparative Example 3-1

[0111] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that in Example 3, except that the dose of irradiation in step 3) is different. The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0112] 1) The preparation of the premix composition is the same as in Example 3.

[0113] 2) The above premix composition is irradiated by a cobalt source at a dose of 60 kGy to obtain a pre-irradiated composition; the pre-irradiated composition is mixed uniformly with 0.40 parts by weight of antioxidant 300 to obtain a mixture, and then 0.19 parts by weight of t-butyl peroxyl laurate is added to the mixture by spraying to obtain the ultra-high molecular weight polyethylene composition.

[0114] 3) The ultra-high molecular weight polyethylene composition was processed into wear plate according to the same method as in Example 3.

[0115] Comparative Example 3-2

[0116] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that in Comparative Example 3-1, except that no tert-butyl peroxyl laurate is added in step 2). The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0117] 1) The preparation of the premix composition is the same as in Comparative Example 3-1;

[0118] 2) The above premix composition was irradiated by a cobalt source at a dose of 60 kGy to obtain a pre-irradiated composition; the pre-irradiated composition was uniformly mixed with 0.40 parts by weight of antioxidant 300 to obtain an ultra-high molecular weight polyethylene composition.

[0119] 3) The ultra-high molecular weight polyethylene composition was processed into wear plate according to the same method as in Comparative Example 3-1.

[0120] Comparative Example 4-1

[0121] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that in Example 4, except that no hindered amine stabilizer GW-123 is added in step 1). The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0122] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 2.8 million, apparent density 0.45 g / cm 3 , average particle size 180 microns), 0.40 parts by weight of a composite antioxidant (mass ratio of antioxidant 1010 to antioxidant 168 is 2:1) were uniformly mixed to form a premix composition;

[0123] 2) The premix composition was irradiated by high-energy electron beam at a dose of 23 kGy to obtain a pre-irradiated composition; the pre-irradiated composition was uniformly mixed with 0.35 parts by weight of antioxidant 300 to obtain a mixture; then 0.06 parts by weight of α,α'-bis-tert-butyl peroxide-1,4-diisopropylbenzene was added to the mixture in a spraying manner to obtain an ultra-high molecular weight polyethylene composition.

[0124] 3) The ultra-high molecular weight polyethylene composition was processed into a pipe according to the same method as in Example 4.

[0125] Comparative Example 4-2

[0126] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that of Comparative Example 4-1, except that no α,α'-bis-tert-butyl peroxy-1,4-diisopropylbenzene is added in step 2). The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0127] 1) The preparation of the premixed composition is the same as that of Comparative Example 4-1;

[0128] 2) The premixed composition is irradiated by high-energy electron beam at a dose of 23 kGy to obtain a pre-irradiated composition; the pre-irradiated composition is uniformly mixed with 0.35 parts by weight of antioxidant 300 to obtain an ultra-high molecular weight polyethylene composition.

[0129] 3) The ultra-high molecular weight polyethylene composition is processed into a pipe according to the same method as in Comparative Example 4-1.

[0130] Comparative Example 5-1

[0131] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that of Example 5, except that no antioxidant is added. The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0132] 1) 100 parts by weight of an ultra-high molecular weight polyethylene resin (viscosity average molecular weight 3.5 million, apparent density 0.40 g / cm 3 , average particle size 260 microns) and 0.05 parts by weight of GW-3853 are uniformly mixed to form a premixed composition;

[0133] 2) The premixed composition is irradiated by high-energy electron beam at a dose of 16 kGy to obtain a pre-irradiated composition; then 0.15 parts by weight of di-tert-butyl diperoxyphthalate is added to the pre-irradiated composition in an impregnation manner to obtain an ultra-high molecular weight polyethylene composition.

[0134] 3) The ultra-high molecular weight polyethylene composition is processed into a pipe according to the same method as in Example 5.

[0135] Comparative Example 5-2

[0136] The preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is similar to that of Comparative Example 5-1, except that no di-tert-butyl diperoxyphthalate is added in step 2). The specific preparation method of the ultra-high molecular weight polyethylene composition provided in this comparative example is as follows:

[0137] 1) The preparation of the premixed composition is the same as that of Comparative Example 5-1;

[0138] 2) The premixed composition is irradiated by high-energy electron beam at a dose of 16 kGy to obtain an ultra-high molecular weight polyethylene composition.

[0139] 3) The UHMWPE composition was processed into pipe according to the same method as in Comparative Example 5-1.

[0140] Comparative Example 6-1

[0141] The preparation method of the UHMWPE composition provided in this comparative example is similar to that in Example 6, except that the composite antioxidant is added in the preparation of the premix composition in step 1. The specific preparation method of the UHMWPE composition provided in this comparative example is as follows:

[0142] 1) 100 parts by weight of UHMWPE resin (viscosity average molecular weight 4.6 million, apparent density 0.44 g / cm3, average particle size 230 microns), 0.04 parts by weight of GW-944 and 0.55 parts by weight of composite antioxidant (mass ratio of antioxidant 330 to thiodipropionic acid ester is 3:1) were uniformly mixed to form a premix composition; 3

[0143] 2) The premix composition was irradiated by a cobalt source at a dose of 35 kGy to obtain a pre-irradiated composition; 0.10 parts by weight of dicumyl peroxide was added to the pre-irradiated composition in a spraying manner to obtain a UHMWPE composition.

[0144] 3) The UHMWPE composition was processed into wear-resistant plate according to the same method as in Example 6.

[0145] Comparative Example 6-2

[0146] The preparation method of the UHMWPE composition provided in this comparative example is similar to that in Comparative Example 6-1, except that no dicumyl peroxide is added in step 2). The specific preparation method of the UHMWPE composition provided in this comparative example is as follows:

[0147] 1) The premix composition was prepared in the same manner as in Comparative Example 6-1.

[0148] 2) The premix composition was irradiated by a cobalt source at a dose of 35 kGy to obtain a UHMWPE composition.

[0149] 3) The UHMWPE composition was processed into wear-resistant plate according to the same method as in Comparative Example 6-1.

[0150] The pipe or plate prepared in each of the above examples and comparative examples was subjected to corresponding tests, and the specific test results are shown in the following table.

[0151] Table 1

[0152]

[0153] ​

[0154] From the data comparison of each example and comparative example in the above table, it can be seen that the ultrahigh molecular weight polyethylene composition obtained according to the technical solution of the present application can be used to process pipes and plates by using the existing pipe and plate production equipment, and a small amount of crosslinking occurs during the forming process, so that the product has a low wear rate (less than or equal to 0.6%), a high load deformation temperature (greater than 80°C), and no color change after long-term storage. If no irradiation is performed (Comparative Example 1) or the irradiation dose is not within the range of the present application (Comparative Example 2, Comparative Example 3-1), or the composition lacks the necessary components (Comparative Example 4-1, Comparative Example 5-1), or the composition preparation steps are different (Comparative Example 6-1), or no peroxide is added (Comparative Example 3-2, Comparative Example 4-2, Comparative Example 5-2, Comparative Example 6-2), the obtained composition cannot meet the modification needs of ultrahigh molecular weight, and the yellow index of the product increases significantly after storage for a period of time, the wear rate of the product is high, and the load deformation temperature is low.

[0155] Moreover, in each example of the above table, the viscosity average molecular weight of the pre-irradiated composition does not change significantly compared to the viscosity average molecular weight of the ultrahigh molecular weight polyethylene resin used. Therefore, it can be seen that the preparation method of the ultrahigh molecular weight polyethylene composition provided by the present application, by selecting appropriate additives (hindered amine stabilizer, antioxidant, and peroxide) and their addition amounts, under a suitable irradiation dose, the ultrahigh molecular weight polyethylene resin in the pre-irradiated composition obtained by the combined action of the ultrahigh molecular weight polyethylene resin, part of the antioxidant, and the hindered amine stabilizer does not crosslink, but is more prone to micro-crosslinking under the action of the peroxide. If the irradiation dose is too large, or the composition lacks the necessary components (Comparative Example 3-1, Comparative Example 4-1, Comparative Example 5-1), the ultrahigh molecular weight polyethylene resin will crosslink to a certain extent after irradiation: the viscosity average molecular weight of the pre-irradiated composition increases by more than 10% compared to the viscosity average molecular weight of the ultrahigh molecular weight polyethylene resin used.

[0156] Of course, the present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications to the present application without departing from the spirit and essence of the present application. However, these corresponding changes and modifications should all fall within the scope of protection of the claims of the present application.

Claims

1. A method for preparing an ultra-high molecular weight polyethylene composition, characterized in that, Includes the following steps: 1) Mix ultra-high molecular weight polyethylene resin, hindered amine stabilizer, and some antioxidants evenly to obtain a premixed composition; 2) After irradiating the premixed composition with a high-energy electron beam of 15-50 kJ or a cobalt source, the remaining antioxidant and peroxide are added to obtain the ultra-high molecular weight polyethylene composition. Based on 100 parts by weight of the ultra-high molecular weight polyethylene resin, the hindered amine stabilizer is 0.01 to 0.05 parts by weight, the antioxidant is 0.4 to 0.8 parts by weight, and the peroxide is 0.03 to 0.2 parts by weight.

2. The ultra-high molecular weight polyethylene composition according to claim 1, characterized in that, The irradiation dose is 20–40 kGy.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the antioxidant in step 1) to the antioxidant in step 2) is 1:0.35 to 4.

4. The preparation method according to claim 3, characterized in that, The mass ratio of the antioxidant in step 1) to the antioxidant in step 2) is 1:1 to 2.

5.

5. The preparation method according to claim 1, characterized in that, The ultra-high molecular weight polyethylene resin has a viscosity-average molecular weight of 1.5 million to 5 million and an apparent density of 0.35 to 0.50 g / cm³. 3 The average particle size is 70–300 micrometers.

6. The preparation method according to claim 1, characterized in that, The hindered amine stabilizer is selected from bis(2,2,6,6,-tetramethyl-4-piperidinyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,2,6,6-tetramethyl-4-piperidinyl stearate, poly{(6-morpholino-5-triazine-2,4-diyl)(2,2,6,6-tetramethylpiperidinyl)iminohexamethylene[(2,2,6,6-tetramethylpiperidinyl)-imino]}, poly{[6-[(1,1,3,3-tetramethylbutyl)amino]]-1,3,5-triazine-2,4-[(2,2,6,6,-tetramethylpiperidinyl)imino]-1,6-hexamethylene[(2,2,6,6-tetramethyl-piperidinyl)imino]-1,6-hexamethylene[(2,2,6,6-tetramethyl-piperidinyl)imino]} The following are polymeric hindered amine stabilizers: [6-tetramethyl-4-piperidinyl)imino]}, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, high molecular weight triazine-piperidin condensate, polymers of the reaction products of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine with 2,4,6-trichloro-1,3,5-triazine, N-butyl-1-butylamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and polymeric hindered amine stabilizers containing structural units of 2,2,6,6-tetramethylpiperidinol-4-methacrylate and / or 1,2,2,6,6-pentamethylpiperidinol-4-methacrylate.

7. The preparation method according to claim 1, characterized in that, The antioxidant includes a primary antioxidant, which is a phenolic antioxidant.

8. The preparation method according to claim 7, characterized in that, The antioxidant also includes a co-antioxidant, which is selected from any one of phosphite antioxidants, acylhydrazine antioxidants, and thioester antioxidants.

9. The preparation method according to claim 1, characterized in that, The peroxide is selected from at least one of tert-butylperoxyisopropyl carbonate, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butylperoxyacetate, di-tert-butyldisperoxyphthalate, tert-butylperoxymaleic acid, cyclohexanone peroxide, tert-butylperoxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, tert-butyl hydroperoxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne, and α,α'-bis-tert-butylperoxy-1,4-diisopropylbenzene.

10. The preparation method according to claim 1, characterized in that, The peroxide is added by spraying, impregnation or splashing.

11. The preparation method according to claim 7, characterized in that, The phenolic antioxidant is selected from at least one of 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxyphenylmethyl)benzene, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-thiobis(6-tert-butyl-3-methylphenol), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

12. The preparation method according to claim 8, characterized in that, The mass ratio of the primary antioxidant to the secondary antioxidant is 2 to 4:1.

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