A silane crosslinked polyethylene pipe resistant to pre-crosslinking and a method for producing the same
The method for preparing silane crosslinked polyethylene pipes by using a specific compounded polymerization inhibitor, silicone masterbatch and long-induction period catalyst masterbatch solves the pre-crosslinking problem in the production process of silane crosslinked polyethylene pipes, and achieves high-efficiency production and excellent long-term mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- RIFENG ENTERPRISE FOSHAN CO LTD
- Filing Date
- 2026-04-17
- Publication Date
- 2026-06-12
AI Technical Summary
Existing silane cross-linked polyethylene pipes have pre-cross-linking issues during the production process, resulting in internal gel particles, surface roughness, and high equipment maintenance frequency. Furthermore, existing polymerization inhibitors affect the degree of cross-linking and long-term performance.
By using a specific ratio of polymerization inhibitor, silicone masterbatch and long-induction period catalyst masterbatch, combined with a specific base resin composition, a one-step production process is adopted to control the pre-crosslinking reaction and ensure that the silane functional groups are uniformly activated during the crosslinking stage.
Effective control of pre-crosslinking improves the degree of crosslinking and long-term mechanical properties of the pipe, reduces production costs and equipment maintenance frequency, and yields high-quality pipes with smooth surfaces.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of polyethylene pipe technology, and more specifically, to a silane cross-linked polyethylene pipe with anti-pre-crosslinking properties and its preparation method. Background Technology
[0002] Silane cross-linked polyethylene (PE-X) pipes have become a core material for replacing traditional metal pipes due to their excellent temperature resistance (operating temperature up to 95℃), creep resistance, and resistance to environmental stress cracking. They are widely used in heating, water supply, and other fields. The manufacturing process involves grafting silane onto the polyethylene molecular chain using a peroxide initiator, followed by catalytic hydrolysis and condensation to form a Si-O-Si cross-linked structure, thereby improving the pipe's mechanical properties and thermal stability.
[0003] Currently, the mainstream production processes for silane cross-linked polyethylene pipes include one-step and two-step methods. The one-step method involves mixing all raw materials at once and then directly extruding them. However, both methods suffer from serious pre-crosslinking problems. During processing, silane is directly exposed to the processing environment and pre-crosslinks upon contact with even trace amounts of moisture, resulting in the formation of gel particles inside the pipe, a rough surface, and a large number of defective products. The pipe pass rate is typically below 85%.
[0004] The two-step method involves preparing component A (silane grafted material) and component B (catalyst masterbatch) separately before mixing and extruding them. However, even during room temperature storage, component A readily absorbs trace amounts of moisture from the environment, undergoing hydrolysis and condensation reactions, leading to pre-crosslinking. This causes a decrease in melt flow rate (MFI) of over 30%, resulting in defects such as particles and dents on the pipe surface during extrusion. Simultaneously, the equipment cleaning cycle is shortened to less than 4 hours, increasing production costs and maintenance frequency.
[0005] Existing technologies also include the addition of crosslinking inhibitors or polymerization inhibitors (such as long-chain silanes) to suppress pre-crosslinking. However, these polymerization inhibitors often reduce the final degree of crosslinking, affecting the long-term performance of the pipe, and their anti-pre-crosslinking effect is limited. Summary of the Invention
[0006] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a silane cross-linked polyethylene pipe with anti-pre-crosslinking properties and a method for preparing the same, the specific technical solution of which is as follows:
[0007] A type of silane crosslinked polyethylene pipe resistant to pre-crosslinking, comprising the following raw materials in parts by weight: The composition includes 100 parts of base resin, 1.5-3 parts of silane coupling agent, 0.08-0.2 parts of initiator, 1.2-2.5 parts of composite anti-pre-crosslinking system, 0.3-0.6 parts of antioxidant, and 0.2-0.5 parts of lubricant. The composite anti-pre-crosslinking system includes a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of (0.3-0.8):(0.5-1):(0.4-0.7).
[0008] Furthermore, the polymerization inhibitor is a sulfur-containing silane derivative, such as thiobis[3-(trimethoxysilane)propane] or 3-thiooctanoyl-1-propyltriethoxysilane; The silicone masterbatch is a fluorinated silicone, and the content of the fluorinated silicone is 40%-45%. The long-induction period catalyst masterbatch includes dibutyltin dilaurate and polyethylene support, wherein the content of dibutyltin dilaurate is 30%-40% and the content of polyethylene support is 60%-70%.
[0009] Further, the base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of (65-70):(20-25):(5-15), and the melt flow rate of the mixture is 1.8-2.2 g / 10min.
[0010] Furthermore, the silane coupling agent is an unsaturated silane coupling agent, and the unsaturated silane coupling agent is vinyltrimethoxysilane.
[0011] Furthermore, the initiator is at least one of dicumyl peroxide, benzoyl tert-butyl peroxide, and bis-tert-butyl dicumyl peroxide.
[0012] Furthermore, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of (1-2):(1-3).
[0013] Furthermore, the lubricant is stearamide.
[0014] In addition, the present invention also provides a method for preparing a silane crosslinked polyethylene pipe with anti-pre-crosslinking properties. The preparation method includes the following steps: S1. According to the formula, mix the base resin, unsaturated silane coupling agent, initiator, composite anti-pre-crosslinking system, antioxidant and lubricant evenly to obtain a mixture; S2. The mixture is melt-blended using a twin-screw extruder, then extruded and granulated to obtain a silane crosslinked polyethylene masterbatch; S3. The silane crosslinked polyethylene masterbatch is extruded using a single-screw extruder to obtain a tube blank; S4. The tube blank is subjected to cross-linking treatment in a humid and hot environment to obtain silane cross-linked polyethylene pipe.
[0015] Furthermore, in step S2, the processing temperature of the twin-screw extruder is 160℃-190℃, and the screw speed is 200r / min-300r / min.
[0016] Furthermore, in step S4, the crosslinking treatment temperature is 70℃-90℃, the relative humidity is 80%-90%, and the crosslinking time is 12-48h.
[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention adds a specific ratio of polymerization inhibitor, silicone masterbatch, and long-induction-period catalyst masterbatch to a polyethylene system. Thiobis[3-(trimethoxysilane)propane] or 3-thiooctanoyl-1-propyltriethoxysilane, with its sulfur-containing groups, can capture free radicals and inhibit cross-linking initiation reactions, thereby preventing the silane grafting onto the polyethylene molecular chain from the source. The silicone masterbatch has extremely low surface energy, providing efficient internal and external lubrication in the melt, reducing frictional heat generation between the material and the screw and barrel, and forming a lubricating film between polymer molecular chains, physically blocking contact between active molecules (such as silane and free radicals) and delaying the reaction. The dibutyltin dilaurate / polyethylene carrier, by being formulated as a "long-induction-period" masterbatch and strictly controlling its addition ratio in the composite system, effectively controls the overall cross-linking of the system.
[0018] 2. This invention uses a specific ratio of linear low-density polyethylene, low-density polyethylene and high-density polyethylene as the matrix resin. This not only utilizes the strength and toughness of linear low-density polyethylene, the excellent processability of low-density polyethylene and the pressure resistance of high-density polyethylene, but also effectively controls the melt flow rate by adjusting the specific ratio, which is beneficial to improving the processing fluidity and pipe performance.
[0019] 3. Overall, this invention can effectively control pre-crosslinking, with virtually no pre-crosslinking during the processing stage. The silane functional groups are retained and are uniformly and fully activated during the crosslinking stage, thereby obtaining a higher and more uniform degree of crosslinking. It has excellent processing stability, superior long-term mechanical properties and resistance to environmental stress cracking, and a smooth and flat product appearance, significantly improving production efficiency and yield.
[0020] 4. This invention uses a one-step production process, which is simple in overall process. While ensuring the performance of the pipe, it eliminates the need for complicated premixing or intermediate steps, thereby reducing equipment investment and production costs. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.
[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0023] An embodiment of the present invention provides an anti-pre-crosslinking silane crosslinked polyethylene pipe, comprising the following raw materials in parts by weight: The composition includes 100 parts of base resin, 1.5-3 parts of silane coupling agent, 0.08-0.2 parts of initiator, 1.2-2.5 parts of composite anti-pre-crosslinking system, 0.3-0.6 parts of antioxidant, and 0.2-0.5 parts of lubricant. The composite anti-pre-crosslinking system includes a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of (0.3-0.8):(0.5-1):(0.4-0.7).
[0024] In one embodiment, the polymerization inhibitor is one of thiobis[3-(trimethoxysilane)propane] or 3-thiooctanoyl-1-propyltriethoxysilane; The silicone masterbatch is a fluorinated silicone, and the content of the fluorinated silicone is 40%-45%. The long-induction-period catalyst masterbatch comprises dibutyltin dilaurate and a polyethylene support, wherein the dibutyltin dilaurate content is 30%-40% and the polyethylene support content is 60%-70%. This invention preferably uses thiobis[3-(trimethoxysilane)propane], whose bissilyl structure can compete with silane for grafting sites, reducing the activity of silanol groups and stably capturing free radicals generated during melt extrusion. The fluorinated groups in the fluorinated silicone further enhance hydrophobicity and chemical inertness, and may also have a certain inhibitory effect on side reactions such as silane hydrolysis and condensation. The long-induction-period catalyst masterbatch uses polyethylene as a support to ensure compatibility with the substrate, and the 30%-40% catalyst content ensures sufficient catalytic efficiency during the crosslinking stage. Overall, the polymerization inhibitor is responsible for "chemically intercepting" free radicals, the silicone masterbatch is responsible for "physical isolation" and improving processing fluidity, and the long-induction-period catalyst is responsible for "delaying the start-up" of the final crosslinking. The three elements intervene at different stages of the reaction chain, forming a three-dimensional, multi-layered anti-pre-crosslinking protective network that can exert a synergistic effect and achieve the ideal anti-pre-crosslinking state.
[0025] In one embodiment, the base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of (65-70):(20-25):(5-15), and the melt flow rate of the mixture is 1.8-2.2 g / 10min.
[0026] In one embodiment, the silane coupling agent is an unsaturated silane coupling agent, and the unsaturated silane coupling agent is vinyltrimethoxysilane.
[0027] In one embodiment, the initiator is at least one of dicumyl peroxide, benzoyl tert-butyl peroxide, and bis-tert-butyl dicumyl peroxide.
[0028] In one embodiment, the antioxidant is prepared by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of (1-2):(1-3). This invention provides a compounded antioxidant where antioxidant 1010 effectively captures free radicals and antioxidant 168 effectively decomposes hydroperoxides, achieving synergistic antioxidant protection and protecting materials from thermo-oxidative aging during processing and service life.
[0029] In one embodiment, the lubricant is stearamide. The lubricant added in this invention provides lubrication, prevents material adhesion to equipment, and complements the internal lubrication of the silicone masterbatch, further ensuring smooth processing.
[0030] In addition, the present invention also provides a method for preparing a silane crosslinked polyethylene pipe with anti-pre-crosslinking properties. The preparation method includes the following steps: S1. According to the formula, mix the base resin, unsaturated silane coupling agent, initiator, composite anti-pre-crosslinking system, antioxidant and lubricant evenly to obtain a mixture; S2. The mixture is melt-blended using a twin-screw extruder, then extruded and granulated to obtain a silane crosslinked polyethylene masterbatch; S3. The silane crosslinked polyethylene masterbatch is extruded using a single-screw extruder to obtain a tube blank; S4. The tube blank is subjected to cross-linking treatment in a humid and hot environment to obtain silane cross-linked polyethylene pipe.
[0031] In one embodiment, in step S2, the processing temperature of the twin-screw extruder is 160°C-190°C, and the screw speed is 200 r / min-300 r / min.
[0032] In one embodiment, in step S3, the processing temperature of the single-screw extruder is 150°C-180°C.
[0033] In one embodiment, in step S4, the crosslinking treatment temperature is 70℃-90℃, the relative humidity is 80%-90%, and the crosslinking time is 12-48h.
[0034] In the above scheme, the degree of crosslinking is controllable, the formulation has excellent resistance to pre-crosslinking, and in the subsequent crosslinking treatment, a crosslinking system with high degree of crosslinking and uniformity can be obtained. The resulting pipe has excellent long-term hydrostatic strength, stress cracking resistance and impact resistance, and the pipe surface is smooth and flat with excellent appearance quality.
[0035] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.
[0036] Example 1: A method for preparing a silane crosslinked polyethylene pipe with anti-pre-crosslinking properties, the method comprising the following steps: S1. By weight, 100 parts of base resin, 2.2 parts of vinyltrimethoxysilane, 0.1 parts of dicumyl peroxide, 1.9 parts of composite anti-pre-crosslinking system, 0.45 parts of antioxidant and 0.3 parts of stearamide are mixed evenly to obtain a mixture. The base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of 70:20:10, and the melt flow rate of the mixture is 2.0 g / 10min. The composite anti-pre-crosslinking system comprises a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of 0.5:0.8:0.6. The polymerization inhibitor is thiobis[3-(trimethoxysilane)propane]. The silicone masterbatch is a fluorinated silicone with a fluorinated silicone content of 45% and a polyethylene carrier content of 55%. The long-induction period catalyst masterbatch comprises dibutyltin dilaurate and a polyethylene carrier, wherein the dibutyltin dilaurate content is 35% and the polyethylene carrier content is 65%. The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 2:3; S2. The mixture is melt-blended and extruded into granules using a twin-screw extruder to obtain silane crosslinked polyethylene masterbatch, with zone 1 at 160°C, zone 2 at 175°C, zone 3 at 185°C, and die head at 185°C; screw speed at 250 rpm. S3. The silane cross-linked polyethylene masterbatch is extruded and molded using a single screw extruder at a processing temperature of 150℃-180℃ to obtain a tube blank; S4. The tube blank is placed in a constant temperature and humidity chamber at 85°C and 85% humidity for 24 hours to obtain silane cross-linked polyethylene pipe.
[0037] Example 2: A method for preparing a silane crosslinked polyethylene pipe with anti-pre-crosslinking properties, the method comprising the following steps: S1. By weight, 100 parts of base resin, 2.5 parts of vinyltrimethoxysilane, 0.15 parts of dicumyl peroxide, 2.0 parts of composite anti-pre-crosslinking system, 0.5 parts of antioxidant and 0.4 parts of stearamide are mixed evenly to obtain a mixture. The base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of 70:20:10, and the melt flow rate of the mixture is 2.0 g / 10min. The composite anti-pre-crosslinking system comprises a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of 0.3:1:0.6. The polymerization inhibitor is thiobis[3-(trimethoxysilane)propane]. The silicone masterbatch is a fluorinated silicone with a fluorinated silicone content of 45% and a polyethylene carrier content of 55%. The long-induction period catalyst masterbatch comprises dibutyltin dilaurate and a polyethylene carrier, wherein the dibutyltin dilaurate content is 35% and the polyethylene carrier content is 65%. The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 2:3; S2. The mixture is melt-blended and extruded into granules using a twin-screw extruder to obtain silane crosslinked polyethylene masterbatch, with zone 1 at 160°C, zone 2 at 175°C, zone 3 at 185°C, and die head at 185°C; screw speed at 250 rpm. S3. The silane cross-linked polyethylene masterbatch is extruded and molded using a single screw extruder at a processing temperature of 150℃-180℃ to obtain a tube blank; S4. The tube blank is placed in a constant temperature and humidity chamber at 85°C and 85% humidity for 24 hours to obtain silane cross-linked polyethylene pipe.
[0038] Example 3: A method for preparing a silane crosslinked polyethylene pipe with anti-pre-crosslinking properties, the method comprising the following steps: S1. By weight, 100 parts of base resin, 2.8 parts of vinyltrimethoxysilane, 0.1 parts of dicumyl peroxide, 2.2 parts of composite anti-pre-crosslinking system, 0.5 parts of antioxidant and 0.5 parts of stearamide are mixed evenly to obtain a mixture. The base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of 70:20:10, and the melt flow rate of the mixture is 2.0 g / 10min. The composite anti-pre-crosslinking system comprises a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of 0.8:0.5:0.6. The polymerization inhibitor is thiobis[3-(trimethoxysilane)propane]. The silicone masterbatch is a fluorinated silicone with a content of 45% and a polyethylene carrier content of 55%. The long-induction period catalyst masterbatch comprises dibutyltin dilaurate and a polyethylene carrier, wherein the dibutyltin dilaurate content is 35% and the polyethylene carrier content is 65%. The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 2:3; S2. The mixture is melt-blended and extruded into granules using a twin-screw extruder to obtain silane crosslinked polyethylene masterbatch, with zone 1 at 160°C, zone 2 at 175°C, zone 3 at 185°C, and die head at 185°C; screw speed at 250 rpm. S3. The silane cross-linked polyethylene masterbatch is extruded and molded using a single screw extruder at a processing temperature of 150℃-180℃ to obtain a tube blank; S4. The tube blank is placed in a constant temperature and humidity chamber at 85°C and 85% humidity for 24 hours to obtain silane cross-linked polyethylene pipe.
[0039] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 did not add a composite anti-pre-crosslinking system, but otherwise it was the same as Example 1.
[0040] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that only a single polymerization inhibitor was added to the composite anti-pre-crosslinking system of Comparative Example 2, while the rest was the same as in Example 1.
[0041] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that only a single silicone masterbatch was added to the composite anti-pre-crosslinking system of Comparative Example 3, while the rest was the same as in Example 1.
[0042] Comparative Example 4: Compared with Example 1, Comparative Example 4 differs in that only a long-induction period catalyst masterbatch is added to the composite anti-pre-crosslinking system of Comparative Example 4, while the rest is the same as Example 1.
[0043] Comparative Example 5: The difference between Comparative Example 5 and Example 1 is that no polymerization inhibitor was added to the composite anti-pre-crosslinking system in Comparative Example 5, while the rest is the same as in Example 1.
[0044] Comparative Example 6: The difference between Comparative Example 6 and Example 1 is that no silicone masterbatch was added to the composite anti-pre-crosslinking system of Comparative Example 6, while the rest is the same as Example 1.
[0045] Comparative Example 7: The difference between Comparative Example 7 and Example 1 is that no long-induction period catalyst masterbatch was added to the composite anti-pre-crosslinking system of Comparative Example 7, while the rest is the same as Example 1.
[0046] Comparative Example 8: The difference between Comparative Example 8 and Example 1 is that the component ratio of the composite anti-pre-crosslinking system in Comparative Example 8 is different, while the rest is the same as in Example 1. In Comparative Example 8, the mass ratio of the polymerization inhibitor, silicone masterbatch, and long-induction period catalyst masterbatch was 0.1:1.5:0.3.
[0047] Comparative Example 9: The difference between Comparative Example 9 and Example 1 is that the base resin in Comparative Example 9 is a single linear low-density polyethylene, while the rest is the same as in Example 1.
[0048] Comparative Example 10: The difference between Comparative Example 10 and Example 1 is that the base resin in Comparative Example 10 is a single high-density polyethylene, while the rest is the same as in Example 1.
[0049] The performance of the silane cross-linked polyethylene pipe samples prepared in Examples 1-3 and the silane cross-linked polyethylene pipe samples prepared in Comparative Examples 1-10 were tested, and the results are shown in Table 1 below.
[0050] Table 1: Performance Test Results
[0051] Note: " / " indicates that a qualified sample could not be produced for testing due to processing failure. The national standard requirement for crosslinking degree is usually >65%. The longer the environmental stress cracking (F0) resistance time, the higher the overall pass rate, which means a better long-term service life.
[0052] Analysis of the data in Table 1 shows that, through component optimization, the present invention exhibits a high degree of crosslinking, forming a dense and complete three-dimensional network structure, resulting in pipes with excellent mechanical properties. Compared to Example 1, Comparative Example 1 did not add a composite anti-pre-crosslinking system, while Comparative Example 4's composite anti-pre-crosslinking system only added a long-induction period catalyst masterbatch, making molding difficult and resulting in unqualified products. Comparative Examples 2-8 changed the composition and component ratio of the composite anti-pre-crosslinking system, affecting not only the degree of crosslinking but also the mechanical properties of the pipes. This indicates that the composite anti-pre-crosslinking system composed of a specific ratio of polymerization inhibitor, silicone masterbatch, and long-induction period catalyst masterbatch in the present invention has a synergistic effect, enabling the regulation of material crosslinking, promoting the acquisition of products with superior mechanical properties, better anti-aging ability and long-term stability, and excellent molding effect, resulting in smooth pipe surfaces without obvious defects. Comparative Examples 9 and 10 changed the ratio of the base resin, but the performance was not as good as that of Example 1, indicating that the present invention, by using a composite of linear low-density polyethylene, low-density polyethylene, and high-density polyethylene as the matrix resin, is beneficial for forming a uniform and efficient crosslinking structure.
[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0054] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A silane cross-linked polyethylene pipe resistant to pre-crosslinking, characterized in that, The preparation materials include the following parts by weight: The composition includes 100 parts of base resin, 1.5-3 parts of silane coupling agent, 0.08-0.2 parts of initiator, 1.2-2.5 parts of composite anti-pre-crosslinking system, 0.3-0.6 parts of antioxidant, and 0.2-0.5 parts of lubricant. The composite anti-pre-crosslinking system includes a polymerization inhibitor, a silicone masterbatch, and a long-induction period catalyst masterbatch in a mass ratio of (0.3-0.8):(0.5-1):(0.4-0.7).
2. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The polymerization inhibitor is a sulfur-containing silane derivative, such as thiobis[3-(trimethoxysilane)propane] or 3-thiooctanoyl-1-propyltriethoxysilane; The silicone masterbatch is a fluorinated silicone, and the content of the fluorinated silicone is 40%-45%. The long-induction period catalyst masterbatch includes dibutyltin dilaurate and polyethylene support, wherein the content of dibutyltin dilaurate is 30%-40% and the content of polyethylene support is 60%-70%.
3. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The base resin is a mixture of linear low-density polyethylene, low-density polyethylene and high-density polyethylene in a mass ratio of (65-70):(20-25):(5-15), and the melt flow rate of the mixture is 1.8-2.2 g / 10min.
4. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The silane coupling agent is an unsaturated silane coupling agent, and the unsaturated silane coupling agent is vinyltrimethoxysilane.
5. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The initiator is at least one of dicumyl peroxide, benzoyl tert-butyl peroxide, and bis-tert-butyl dicumyl peroxide.
6. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of (1-2):(1-3).
7. The silane cross-linked polyethylene pipe according to claim 1, characterized in that, The lubricant is stearamide.
8. A method for preparing a silane cross-linked polyethylene pipe with anti-pre-crosslinking properties, characterized in that, The preparation method is used to prepare the silane crosslinked polyethylene pipe with anti-pre-crosslinking as described in any one of claims 1 to 7, and the preparation method includes the following steps: S1. According to the formula, mix the base resin, unsaturated silane coupling agent, initiator, composite anti-pre-crosslinking system, antioxidant and lubricant evenly to obtain a mixture; S2. The mixture is melt-blended using a twin-screw extruder, then extruded and granulated to obtain a silane crosslinked polyethylene masterbatch; S3. The silane crosslinked polyethylene masterbatch is extruded using a single-screw extruder to obtain a tube blank; S4. The tube blank is subjected to cross-linking treatment in a humid and hot environment to obtain silane cross-linked polyethylene pipe.
9. The preparation method according to claim 8, characterized in that, In step S2, the processing temperature of the twin-screw extruder is 160℃-190℃, and the screw speed is 200r / min-300r / min.
10. The preparation method according to claim 8, characterized in that, In step S4, the crosslinking treatment temperature is 70℃-90℃, the relative humidity is 80%-90%, and the crosslinking time is 12-48h.