Anti-scorching agent, anti-scorching composition, semi-conductive shielding material, and preparation method and application of semi-conductive shielding material

Abstract

The invention relates to the technical field of power cable materials, and discloses an anti-scorching agent, a composition and a semiconductive shielding material as well as a preparation method and application of the semiconductive shielding material, and the anti-scorching agent comprises a structural unit provided by a monomer as shown in a formula (A) and a structural unit provided by a monomer as shown in a formula (B); wherein R < 2 >, R < 3 >, R < 4 > and R < 5 > are respectively at least one of H, OH and C1-C3 alkyl groups; r < 6 >, R < 7 >, R < 8 > and R < 9 > are at least one of H and C1-C3 alkyl groups respectively; the molar ratio of the content of the monomer shown in the formula (A) to the content of the monomer shown in the formula (B) is 1: (0.5-5); # imgabs0 #, formula (A); wherein R1 is at least one of-NH2,-CH3NH2, # imgabs 1 # and # imgabs 2 #, and R1 is at least one of-NH2,-CH3NH2, # imgabs 1 # and # imgabs # imgabs3 #, formula (B).

Description

Technical Field

[0001] The present invention relates to the technical field of power cable materials, and specifically relates to an anti-scorch agent, a composition, a semi-conductive shielding material, a preparation method thereof, and an application thereof. Background Art

[0002] The power cable industry is a basic industrial sector and an important supporting industry for the two major national economic pillar industries of electricity and communication, and has an extremely important position in the national economy. With the successive investment in upgrading and construction of large-scale projects such as power grid renovation and UHV, the power cable industry has developed rapidly. Especially for high-voltage and extra-high-voltage submarine cables, as the only channel for transmitting electrical energy from offshore wind turbines to land, connecting the onshore centralized control center and the offshore booster station, they are called the main arteries of wind power projects and are an important part of offshore facilities. As an important part of the high-voltage cable structure, the semi-conductive shielding layer can not only evenly distribute the electric field in the insulating layer and eliminate the air gap at the interface between the conductor and the insulating layer to reduce the damage to the cable insulating layer caused by electrical stress concentration, but also help to inhibit the injection of space charges in the insulating layer and the growth of electrical trees, and extend the service life of the cable. The continuous improvement of the cable voltage grade puts forward higher technical requirements for the performance of the semi-conductive shielding layer, and it is particularly important to maintain a perfect shielding layer during the cable processing and preparation process.

[0003] Therefore, in the research of shielding materials, it is of great research significance and value to innovate and develop new anti-scorch agents and shielding material formulations to inhibit cross-linking reactions and explore suitable processing technologies. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem of the relatively short scorch time of the existing shielding materials, and to provide an anti-scorch agent, a composition, a semi-conductive shielding material, a preparation method thereof, and an application thereof. This anti-scorch agent can achieve the anti-scorch effect of the semi-conductive shielding material and is beneficial to long-term extrusion.

[0005] To achieve the above purpose, in the first aspect of the present invention, an anti-scorch agent is provided, wherein the anti-scorch agent includes structural units provided by monomers shown in formula (A) and structural units provided by monomers shown in formula (B); , formula (A); , formula (B); Wherein, in formula (A), R1 is at least one of -NH2, -CH3NH2, and ; Wherein, R6, R7, R8, and R9 are the same or different, and each is at least one of H and C1-C3 alkyl; Among them, in formula (B), R2, R3, R4, and R5 are the same or different and are each at least one of H, OH, and C1-C3 alkyl groups; Among them, the molar ratio of the contents of the monomer represented by formula (A) and the monomer represented by formula (B) is 1:(0.5-5).

[0006] The second aspect of the present invention provides a method for preparing the foregoing anti-scorching agent, wherein the preparation method includes: Melting and blending the monomer represented by formula (A) and the monomer represented by formula (B), and pelletizing the obtained blend, and obtaining the anti-scorching agent after cooling treatment; Among them, the molar ratio of the amounts of the monomer represented by formula (A) and the monomer represented by formula (B) is 1:(0.5-5).

[0007] The third aspect of the present invention provides an anti-scorching agent prepared by the foregoing preparation method.

[0008] The fourth aspect of the present invention provides a composition for preparing a semi-conductive shielding material, wherein the composition includes an anti-scorching agent, a copolymer matrix, low-density polyethylene, a processing aid, and a cross-linking agent, wherein the anti-scorching agent is the foregoing anti-scorching agent.

[0009] The fifth aspect of the present invention provides a method for preparing a semi-conductive shielding material using the foregoing composition, wherein the method includes: (S1) Kneading the foregoing anti-scorching agent, copolymer matrix, low-density polyethylene, and processing aid in contact; (S2) Extruding and pelletizing the mixture obtained in step (S1) to obtain a premix; (S3) Mixing the cross-linking agent and the premix in contact and then cooling to obtain a semi-conductive shielding material.

[0010] The sixth aspect of the present invention provides a semi-conductive shielding material prepared by the foregoing method.

[0011] The seventh aspect of the present invention provides an application of the foregoing semi-conductive shielding material in submarine cables.

[0012] Through the above technical solutions, the beneficial effects of the present invention are as follows: (1) By using the scorch retardant of the present invention, the vinyl group on the monomer shown in formula (A) serves as a grafting reaction functional group, and the carbonyl group and amino group serve as deep trap groups, which can be introduced as the first functional grafting monomer to introduce hole and electron traps and enhance the antioxidant performance; the monomer shown in formula (B) has three carbonyl groups with deep trapping functions and three vinyl groups for grafting reactions, and is introduced as the second functional grafting monomer to introduce electron traps to assist the monomer shown in formula (A) to graft onto macromolecules. Therefore, some of the vinyl groups in the monomer shown in formula (B) with a certain crosslinking aid function are used to assist the grafting reaction of the monomer shown in formula (A) with macromolecules, which can slow down the crosslinking reaction and increase the scorch resistance.

[0013] (2) Further, the present invention ensures the rationality of the crosslinking reaction kinetics by adding low-density polyethylene to raw materials such as the copolymer matrix and performing co-grafting modification with the specific scorch retardant of the present invention in the co-grafting system, and does not affect the manufacture of cables. At the same time, it enhances the heat and oxygen aging resistance, realizes the scorch resistance effect of the semi-conductive shielding material, and is beneficial to long-term extrusion. Description of the Drawings

[0014] Figure 1 is a schematic diagram of the mechanism of the PrMA / TMPTMA co-grafting showing scorch resistance performance; Figure 2 is a schematic flow chart of the preparation method of the semi-conductive shielding material provided by the present invention; Figure 3 is the pressure-time change curve of the shielding materials with different formulations in Example 5 and Comparative Examples 1-5 during long-term extrusion; Figure 4 is the infrared spectrum of the shielding material prepared in Example 1 with PrMA / TMPTMA as the scorch retardant. Detailed Embodiments

[0015] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0016] As described above, the first aspect of the present invention provides a scorch retardant, wherein the scorch retardant includes a structural unit provided by the monomer shown in formula (A) and a structural unit provided by the monomer shown in formula (B); , formula (A); , formula (B); Among them, in formula (A), R1 is -NH2, -CH3NH2, and at least one of; Among them, R6, R7, R8, and R9 are the same or different, and each is at least one of H and C1-C3 alkyl; Among them, in formula (B), R2, R3, R4, and R5 are the same or different, and each is at least one of H, OH, and C1-C3 alkyl; Among them, the molar ratio of the contents of the monomer represented by formula (A) and the monomer represented by formula (B) is 1:(0.5-5).

[0017] According to the present invention, preferably, in formula (A), R1 is -NH2, -CH3NH2, and at least one of; among them, R6, R7, R8, and R9 are the same or different, and each is at least one of H, methyl, and ethyl; More preferably, R1 is .

[0018] According to the present invention, in formula (B), R2, R3, R4, and R5 are the same or different, and each is at least one of H, OH, methyl, and ethyl.

[0019] According to the present invention, even more preferably, the structural formula of the monomer represented by formula (A) is: .

[0020] According to the present invention, even more preferably, the structural formula of the monomer represented by formula (B) is: .

[0021] That is, even more preferably, the anti-scorching agent includes a structural unit provided by the polar compound 3-[(4-phenylaminophenyl)amino]-2-hydroxypropyl methacrylate (PrMA) and a structural unit provided by the polar compound trimethylolpropane trimethacrylate (TMPTMA).

[0022] According to the present invention, the molar ratio of the contents of the monomer represented by formula (A) and the monomer represented by formula (B) is preferably 1:(2-4).

[0023] The inventors of the present invention have found that: by using the scorch retardant of the present invention, the vinyl group on the monomer shown in formula (A) is used as a grafting reaction functional group, and the carbonyl group and amino group are used as deep trap groups, which can be introduced as the first functional grafting monomer into hole and electron traps and enhance the antioxidant performance; the monomer shown in formula (B) has three carbonyl groups with deep trapping functions and three vinyl groups for grafting reactions, and is introduced as the second functional grafting monomer into electron traps to assist the monomer shown in formula (A) to graft onto macromolecules. Therefore, some of the vinyl groups in the monomer shown in formula (B) with a certain crosslinking aid function are used to assist the grafting reaction of the monomer shown in formula (A) with macromolecules, which can slow down the crosslinking reaction and increase the scorch resistance. The co-grafting system ensures the rationality of the crosslinking reaction kinetics and does not affect the manufacture of cables. At the same time, it enhances the heat and oxygen aging resistance, achieves the scorch resistance effect of the semi-conductive shielding material, and is beneficial to long-time extrusion.

[0024] In the present invention, it should be noted that: "scorch" is an accumulation of the effects of heat and time on the shielding material, which is a premature vulcanization phenomenon. It will cause difficulties in cable processing, damage the surface smoothness and shielding performance of the shielding layer, and even lead to uneven "scabbing" of the shielding layer, affecting the long-time extrusion of cable production.

[0025] The second aspect of the present invention provides a preparation method of the aforementioned scorch retardant, wherein the preparation method includes: melt-blending the monomer shown in formula (A) and the monomer shown in formula (B), and pelletizing the obtained blend, and obtaining the scorch retardant after cooling treatment; Among them, the molar ratio of the amounts of the monomer shown in formula (A) and the monomer shown in formula (B) is 1:(0.5 - 5).

[0026] According to the present invention, the preparation method does not require an initiator. The monomer shown in formula (A) and the monomer shown in formula (B) are mixed in a certain dosage ratio, melt-blended, and then the obtained blend is pelletized for standby, and the scorch retardant is obtained after cooling.

[0027] According to the present invention, the molar ratio of the amounts of the monomer shown in formula (A) and the monomer shown in formula (B) is preferably 1:(2 - 4).

[0028] According to the present invention, the conditions for the melt-blending include: the temperature is 100 - 120 °C, the rotation speed is 50 - 70 rpm, and the time is 10 - 15 min; preferably, the conditions for the melt-blending include: the temperature is 105 - 115 °C, the rotation speed is 55 - 65 rpm, and the time is 12 - 13 min.

[0029] The third aspect of the present invention provides a scorch retardant prepared by the aforementioned preparation method.

[0030] A fourth aspect of the present invention provides a composition for preparing a semiconductive shielding material, wherein the composition comprises one or more of an anti-scorching agent, a copolymer matrix, low-density polyethylene, a processing aid, and a crosslinking agent, and wherein the anti-scorching agent is the aforementioned anti-scorching agent.

[0031] In the present invention, preferably, the anti-scorching agent is a mixed auxiliary agent with the synergistic grafting effect of TMPTMA and PrMA; the crosslinking agent is dicumyl peroxide (DCP). Since TMPTMA has the function of a crosslinking auxiliary agent, the amount of DCP needs to be reduced when adding TMPTMA to coordinate the crosslinking reaction kinetics of the material.

[0032] Furthermore, the present invention adds low-density polyethylene to raw materials such as a copolymer matrix and performs synergistic graft modification with a specific anti-scorching agent of the present invention, such as Figure 1 shown, Figure 1 is a schematic diagram of the mechanism of the anti-scorching performance exhibited by the synergistic grafting of PrMA / TMPTMA. Among them, the vinyl group on PrMA is used as a grafting reaction functional group, and the carbonyl group and amino group are used as deep trap groups, which can be introduced as a first functional graft monomer to form hole and electron traps and enhance the antioxidant performance; TMPTMA has three carbonyl groups with deep trapping functions and three vinyl groups for grafting reactions, and is introduced as a second functional graft monomer to introduce electron traps to assist the grafting of PrMA onto macromolecules. Therefore, some vinyl groups in TMPTMA with a certain crosslinking auxiliary agent function are used to assist the grafting reaction of PrMA with macromolecules, which can slow down the crosslinking reaction and increase the anti-scorching performance. The co-grafting system ensures the rationality of the crosslinking reaction kinetics and does not affect the manufacture of cables, while enhancing the heat and oxygen aging resistance ability, achieving the anti-scorching effect of the semiconductive shielding material and being beneficial for long-time extrusion.

[0033] According to the present invention, the vinyl acetate content in the copolymer matrix is 15-45 wt%, and the melt index under the conditions of 190 °C and 2.16 kg is 3-50 g / 10 min.

[0034] According to the present invention, under the conditions of 190 °C and 2.16 kg, the melt index of the low-density polyethylene is 35-50 g / 10 min.

[0035] In the present invention, the melt index is measured according to the ASTM D1238 standard at 190 °C under a test load of 2.16 kg.

[0036] According to the present invention, the copolymer matrix is selected from one or more of ethylene-vinyl acetate copolymer (EVA), ethylene-butyl acrylate copolymer (EBA), ethylene-ethyl acrylate copolymer (EEA), and polypropylene (PP).

[0037] According to the present invention, the processing aid includes one or more of an antioxidant, conductive carbon black, and a lubricating dispersant.

[0038] According to the present invention, the antioxidant is selected from a mixture composed of one or more of antioxidant AO-60, antioxidant HP-10, antioxidant 168, antioxidant 300, antioxidant 1010, antioxidant 1024, antioxidant 1035, antioxidant 1076, and antioxidant DSTP.

[0039] According to the present invention, the average particle size of the conductive carbon black is 30 - 60 nm, the BET specific surface area is 200 - 400 m 2 / g, the iodine absorption value is 65 - 75 mg / g, and the oil absorption value is 140 - 200 cc / 100 g.

[0040] According to the present invention, the lubricating dispersant is selected from a mixture composed of one or more of polyethylene wax, polypropylene wax, EVA wax, erucamide, and oleamide.

[0041] According to the present invention, the crosslinking agent is selected from one or more of dicumyl peroxide, di-tert-butylcumyl peroxide, triallyl isocyanurate, vinyltrimethoxysilane, vinyltriethoxysilane, dibutyltin dilaurate, and triallyl cyanurate.

[0042] According to the present invention, the composition includes: 0.1 - 4 parts of the scorch retarder; 60 - 100 parts of the copolymer matrix; 5 - 35 parts of the low-density polyethylene; 0.2 - 1.5 parts of the antioxidant; 45 - 90 parts of the conductive carbon black; 1 - 10 parts of the lubricating dispersant; 0.5 - 3 parts of the crosslinking agent.

[0043] Preferably, the composition includes: 0.5 - 4 parts of the scorch retarder; 70 - 90 parts of the copolymer matrix; 15 - 30 parts of the low-density polyethylene; 0.6 - 1.2 parts of the antioxidant; 50 - 75 parts of the conductive carbon black; 4 - 8 parts of the lubricating dispersant; 1 - 2 parts of the crosslinking agent.

[0044] More preferably, the composition includes: 0.8 part of the scorch retarder; 80 parts of the copolymer matrix; 25 parts of the low-density polyethylene; 1 part of the antioxidant; 60 parts of the conductive carbon black; 6 parts of the lubricating dispersant; 1.2 parts of the crosslinking agent.

[0045] In the present invention, it should be noted that "parts" is equivalent to "parts by weight".

[0046] The fifth aspect of the present invention provides a method for preparing a semi-conductive shielding material using the aforementioned composition, wherein the method includes: (S1) Contacting the aforementioned scorch retardant, copolymer matrix, low-density polyethylene, and processing aid for kneading; (S2) Extruding and pelletizing the kneaded material obtained in step (S1) to obtain a premix; (S3) Contacting the crosslinking agent and the premix for mixing and then cooling to obtain a semi-conductive shielding material.

[0047] According to the present invention, in step (S1), the conditions for the kneading include: kneading at 100 - 120 °C for 10 - 15 min, preferably, kneading at 105 - 115 °C for 11 - 13 min.

[0048] According to the present invention, in step (S3), the conditions for the mixing include: mixing at 50 - 80 °C for 5 - 15 min, preferably, mixing at 70 - 75 °C for 10 - 12 min.

[0049] According to a particularly preferred embodiment of the present invention, as Figure 2 shown, Figure 2 is a schematic flow chart of the method for preparing a semi-conductive shielding material provided by the present invention. A method for preparing a semi-conductive shielding material includes: (S1) Sequentially putting the formulated amounts of copolymer matrix, scorch retardant (for example, PrMA / TMPTMA), low-density polyethylene (LDPE), conductive carbon black, antioxidant, and lubricating dispersant into a mixer for kneading (mixing), the kneading temperature is 100 - 120 °C, and the time is 10 - 15 minutes; (S2) After the kneaded material is discharged, it is put into an extruder for extrusion and pelletizing to obtain a premix; (S3) Mixing the premix with the formulated amount of crosslinking agent (DCP) in a container at 50 - 80 °C for 5 - 15 minutes and then cooling to obtain a semi-conductive shielding (scorch retardant shielding material).

[0050] The present invention simplifies the production process and has a simpler preparation method by directly adding an anti-scorch agent to the raw materials and conducting kneading in an extruder, without pre-making an anti-scorch masterbatch.

[0051] The sixth aspect of the present invention provides a semiconductive shielding material prepared by the method described above.

[0052] According to the present invention, the scorch time of the semiconductive shielding material at 110 °C is 5 - 7 min, preferably 6.5 - 7 min.

[0053] The seventh aspect of the present invention provides an application of the semiconductive shielding material described above in submarine cables.

[0054] According to the present invention, in the process of applying the semiconductive shielding material described above in submarine cables, due to the synergistic grafting effect of different types of vinyl in PrMA / TMPTMA on the chemical reaction of the crosslinking agent, the application conditions include: melting and blending the semiconductive shielding material in a torque rheometer at 100 - 120 °C and a rotational speed of 50 - 70 rpm; then, pressing and forming the obtained blend in a platen curing machine at a temperature of 100 - 120 °C and a pressure of 10 - 20 MPa; and completing the crosslinking and grafting reaction by pressing the mixture at 160 - 190 °C and 10 - 20 MPa for 20 - 40 minutes.

[0055] In the present invention, the semiconductive shielding material can be applied to high-voltage long-duration submarine cables.

[0056] In the present invention, the semiconductive shielding material is preferably used for direct current.

[0057] The present invention will be described in detail below through examples.

[0058] In the following examples and comparative examples: The specific gravity parameter is measured by the method of GB / T 1033.1 - 2008; The tensile strength parameter is measured by the method of GB / T 1040.2 - 2022; The tensile strength change rate parameter is measured by the method of GB / T 1040.2 - 2022; The elongation at break parameter is measured by the method of GB / T 1040.2 - 2022; The elongation at break change rate parameter is measured by the method of GB / T 1040.2 - 2022; The volume resistivity parameter is measured by the method of GB / T 31838.2 - 2019; The thermal elongation parameter is measured by the method of GB / T 2951.21 - 2008; The permanent deformation parameters after cooling are measured by the method of GB / T 2951.21-2008; The scorch time is measured by the method of the internal mixer system of the Hap torque rheometer at 110 °C and a rotational speed of 60 rpm.

[0059] Example 1 This example is to illustrate the anti-scorch agent and the semi-conductive shielding compound prepared by the present invention.

[0060] Preparation method of the anti-scorch agent: Without the action of an initiator, the monomer a (3-[(4-phenylaminophenyl)amino]-2-hydroxypropyl methacrylate) shown in formula (A) and the monomer b (trimethylolpropane trimethacrylate) shown in formula (B) are mixed in a molar ratio of 1:3, and melt-mixed at 110 °C and a rotational speed of 60 rpm; then, the obtained blend is granulated and reserved, and the anti-scorch agent is obtained after cooling; As a result, the prepared anti-scorch agent (PrMA / TMPTMA) includes the structural units provided by the monomer shown in formula (A) and the structural units provided by the monomer shown in formula (B), and the molar ratio is 1:3; and the weight-average molecular weight of this anti-scorch agent is 200,000.

[0061] , formula (A); , formula (B).

[0062] The composition for preparing the semi-conductive shielding compound includes: 0.1 part of anti-scorch agent (PrMA / TMPTMA), 100 parts of copolymer matrix (EVA) (the vinyl ester content is 20 wt%, and its melt index is about 20 g / 10 min, such as EVA20-20), 35 parts of LDPE (the melt index is about 20 g / 10 min, such as PE-500CA), 45 parts of conductive carbon black (the average particle size is 30-60 nm, the BET specific surface area is 200-400 m 2 / g, the iodine absorption value is 65-75 mg / g, the oil absorption value is 140-200 cc / 100 g, such as BP2000), 0.2 part of antioxidant (1010), 1 part of lubricating and dispersing agent (EVA wax), 3 parts of cross-linking agent (DCP).

[0063] The preparation method of the semi-conductive shielding compound for high-voltage submarine cables using the above composition for preparing the semi-conductive shielding compound includes the following steps: (S1) The formulated amounts of copolymer matrix, anti-scorch agent, low-density polyethylene, conductive carbon black, antioxidant and lubricating and dispersing agent are successively put into an internal mixer for mixing, the mixing temperature is 110 °C, and the time is 12 minutes; (S2) After the mixed material is discharged, it is put into an extruder for extrusion granulation to obtain a premix; (S3) Mix the premix with a formulation amount of a crosslinking agent in a container at 70 °C. After mixing for 10 minutes, cool to obtain a product.

[0064] As a result, a semiconductive shielding material was prepared for standby (for high-voltage submarine cables).

[0065] Figure 4 It is the infrared spectrum of the shielding material with PrMA / TMPTMA as the scorch retardant prepared in Example 1; wherein the PrMA / TMPTMA shielding material enhanced the shoulder peak at the 1650 cm -1 position, representing more C=C stretching vibrations in TMPTMA. At the same time, the characteristic N-H bond stretching vibration in PrMA was shown at the 3400 cm -1 position, successfully confirming that the antioxidant was grafted synergistically onto the polymer chain in the shielding material with PrMA / TMPTMA as the scorch retardant.

[0066] Example 2 This example is to illustrate the scorch retardant and semiconductive shielding material prepared by the present invention.

[0067] The scorch retardant and semiconductive shielding material were prepared in the same manner as in Example 1, except that the components of the composition for preparing the semiconductive shielding material were the same as those in Example 1, but the specific component contents were different (different weight fractions): 4 parts of scorch retardant, 60 parts of EVA, 5 parts of LDPE, 90 parts of conductive carbon black, 1.5 parts of antioxidant, 10 parts of lubricating and dispersing agent, 0.5 part of crosslinking agent; the specific preparation method was the same as that in Example 1; a semiconductive shielding material was prepared for standby (for high-voltage submarine cables).

[0068] Example 3 This example is to illustrate the scorch retardant and semiconductive shielding material prepared by the present invention.

[0069] The scorch retardant and semiconductive shielding material were prepared in the same manner as in Example 1, except that the components of the composition for preparing the semiconductive shielding material were the same as those in Example 1, but the specific component contents were different (different weight fractions): 0.5 part of scorch retardant, 90 parts of EVA, 15 parts of LDPE, 50 parts of conductive carbon black, 0.6 part of antioxidant, 4 parts of lubricating and dispersing agent, 1 part of crosslinking agent; the specific preparation method was the same as that in Example 1; a semiconductive shielding material was prepared for standby (for high-voltage submarine cables).

[0070] Example 4 This example is to illustrate the scorch retardant and semiconductive shielding material prepared by the present invention.

[0071] The anti-scorching agent and the semi-conductive shielding material were prepared in the same manner as in Example 1, except that the components of the composition for preparing the semi-conductive shielding material were the same as those in Example 1, but the specific component contents were different (different weight fractions): 2 parts of anti-scorching agent, 70 parts of EVA, 30 parts of LDPE, 75 parts of conductive carbon black, 1.2 parts of antioxidant, 8 parts of lubricating and dispersing agent, and 2 parts of cross-linking agent; the specific preparation method was the same as that in Example 1; the semi-conductive shielding material was prepared for standby (for high-voltage submarine cables).

[0072] Example 5 This example is to illustrate the anti-scorching agent and the semi-conductive shielding material prepared by the present invention.

[0073] The anti-scorching agent and the semi-conductive shielding material were prepared in the same manner as in Example 1, except that the components of the composition for preparing the semi-conductive shielding material were the same as those in Example 1, but the specific component contents were different (different weight fractions): 0.8 part of anti-scorching agent, 80 parts of EVA, 25 parts of LDPE, 60 parts of conductive carbon black, 1 part of antioxidant, 6 parts of lubricating and dispersing agent, and 1.2 parts of cross-linking agent; the specific preparation method was the same as that in Example 1; the semi-conductive shielding material was prepared for standby (for high-voltage submarine cables).

[0074] Example 6 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that "anti-scorching agent (PrMA / TMPTMA)" in Example 1 was replaced with 2-(dimethylamino)ethyl methacrylate / pentaerythritol triacrylate (MAEMA / PETA) with a molar ratio of 1:3; and the weight-average molecular weight of this anti-scorching agent was 50,000.

[0075] , formula (A); , formula (B).

[0076] Among them, the preparation method of the semi-conductive shielding material for high-voltage submarine cables using the composition for preparing the semi-conductive shielding material was the same as that in Example 1; the semi-conductive shielding material was prepared for standby (for high-voltage submarine cables).

[0077] Example 7 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that "anti-scorching agent (PrMA / TMPTMA)" in Example 1 was replaced with glycerol methacrylate / trihydroxyethylane triacrylate (GMAA / TMEATA) with a molar ratio of 1:3; and the weight-average molecular weight of this anti-scorching agent was 150,000.

[0078] , formula (A); , formula (B).

[0079] Among them, the preparation method of the semi-conductive shielding material for high-voltage submarine cables using the composition for preparing the semi-conductive shielding material is the same as that in Example 1; the semi-conductive shielding material is prepared for standby (for high-voltage submarine cables).

[0080] Example 8 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that: the preparation method of the scorch retarder in Example 1 was modified as follows: without the action of an initiator, PrMA and TMPTMA were mixed at a molar ratio of 1:6, and melt-mixed at 110 °C and a rotation speed of 60 rpm. Then, the obtained blend was granulated for standby, and the scorch retarder was obtained after cooling; As a result, the prepared scorch retarder (PrMA / TMPTMA) included the monomer shown in formula (A) and the monomer shown in formula (B), and the molar ratio was 1:6; and the weight-average molecular weight of this scorch retarder was 250,000.

[0081] , formula (A); , formula (B).

[0082] Among them, the preparation method of the semi-conductive shielding material for high-voltage submarine cables using the composition for preparing the semi-conductive shielding material is the same as that in Example 1; the semi-conductive shielding material is prepared for standby (for high-voltage submarine cables).

[0083] Example 9 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that: the "scorch retarder (PrMA / TMPTMA)" in Example 1 was replaced with "3-[(4-phenylaminophenyl)amino]-2-hydroxypropyl methacrylate and TMPTMA" obtained after alkyl substitution, and the molar ratio was 1:3; and the weight-average molecular weight of this scorch retarder was 250,000.

[0084] , formula (A); , formula (B).

[0085] Among them, the preparation method of the semi-conductive shielding material for high-voltage submarine cables using the composition for preparing the semi-conductive shielding material is the same as that in Example 1; the semi-conductive shielding material is prepared for standby (for high-voltage submarine cables).

[0086] Comparative Example 1 The scorch retarder and the semi-conductive shielding material were prepared in the same manner as in Example 5, except that the composition for preparing the semi-conductive shielding material "did not contain the scorch retarder PrMA / TMPTMA".

[0087] Comparative Example 2 The anti-scorch agent and semi-conductive shielding compound were prepared in the same manner as in Example 5, except that in the composition for preparing the semi-conductive shielding compound, "the anti-scorch agent does not contain PrMA and only contains a single TMPTMA".

[0088] Comparative Example 3 The anti-scorch agent and semi-conductive shielding compound were prepared in the same manner as in Example 5, except that in the composition for preparing the semi-conductive shielding compound, "the anti-scorch agent does not contain TMPTMA and only contains a single PrMA".

[0089] In addition, a long-term extrusion test was carried out on the shielding compounds in Example 5 and Comparative Examples 1-3, and a long-term extrusion experiment was carried out on insulating compounds with different formulations. The test method for long-term extrusion was to use a single-screw extruder with a pressure sensor in front of the screen, the extrusion temperature was 110 °C, and the rotation speed was 60 rpm; and the change of extrusion pressure with time was studied. The test results are as Figure 3 shown Figure 3 Figure for the pressure-time change curve of shielding compounds with different formulations during long-term extrusion; compared with the long-term extrusion of the shielding compounds in Example 5 (red five-pointed star line) using the best shielding compound formulation with a new anti-scorch agent and other Comparative Examples 1-5, it can be seen from Figure 3 that: when the shielding compounds provided in Comparative Examples 1-5 were extruded, the extrusion pressure fluctuated greatly, and the slope of the corresponding fitting curve increased rapidly, and the long-term extrusion could not be reflected. When the high-voltage submarine cable semi-conductive shielding compound provided in Example 5 was extruded for a long time, the extrusion pressure fluctuated little and had good long-term stability, which was significantly stronger than the semi-conductive shielding compounds without the anti-scorch agent PrMA / TMPTMA and single anti-scorch agents, and had excellent long-term extrusion stability.

[0090] Comparative Example 4 The semi-conductive shielding compound was prepared in the same manner as in Example 1, except that "the anti-scorch agent (PrMA / TMPTMA)" in Example 1 was replaced with "bisphenol A phosphazene / hexa-phenoxy cyclotriphosphazene, N3P3(O−C6H4−C(CH3)2−C6H4−O)6 and N3P3(OPh)6, and the molar ratio was 1:3".

[0091] Among them, the preparation method of the high-voltage submarine cable semi-conductive shielding compound using the composition for preparing the semi-conductive shielding compound was the same as that in Example 1; the semi-conductive shielding compound was prepared for standby (for high-voltage submarine cables).

[0092] Comparative Example 5 The semi-conductive shielding compound was prepared in the same manner as in Example 1, except that "the monomers shown in formula (A) and the monomers shown in formula (B), and the molar ratio was 1:3" in Example 1 was replaced with "the monomers shown in formula (A) and the monomers shown in formula (B), and the molar ratio was 3:1".

[0093] Among them, the preparation method of the semiconductive shielding material for high-voltage submarine cables using the composition for preparing semiconductive shielding material is the same as that in Example 1; the obtained semiconductive shielding material is reserved for use (for high-voltage submarine cables).

[0094] Application Example The semiconductive shielding masterbatches prepared in Examples 1-9 and Comparative Examples 1-5 were melt-mixed in a torque rheometer at a rotational speed of 110 °C and 60 rpm. Then, the obtained blend was compression-molded in a platen curing machine at a temperature of 110 °C and a pressure of 15 MPa. After completing the crosslinking and grafting reactions by pressing the mixture at 175 °C and 15 MPa for 30 minutes, a sheet sample was obtained, and the basic physical and chemical properties were tested. Also, in the internal mixer system of the torque rheometer, the scorch time T10 was tested at a temperature of 110 °C and 60 rpm, and the results are shown in Table 1.

[0095] Table 1

[0096] Table 1 (continued)

[0097] As shown in the performance tables of the anti-scorch semiconductive shielding materials for high-voltage cables obtained in Examples 1-9 and Comparative Examples 1-5 in Table 1 and Table 1 (continued). Under the optimal formulation conditions, the scorch time of the semiconductive shielding material in Example 5 was significantly delayed, showing the best anti-scorch performance.

[0098] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. An anti-scorch agent, characterized in that, The scorch retarder comprises structural units provided by a monomer represented by formula (A) and structural units provided by a monomer represented by formula (B); , formula (A); , formula (B); Among them, in formula (A), R1 is at least one of -NH2, -CH3NH2, and ; wherein R6, R7, R8, and R9 are the same or different and are each at least one of H and C1-C3 alkyl groups; wherein, in formula (B), R2, R3, R4, and R5 are the same or different and are each at least one of H, OH, and C1-C3 alkyl groups; wherein the molar ratio of the content of the monomer represented by formula (A) to the content of the monomer represented by formula (B) is 1:(0.5 - 5).

2. The scorch retarder according to claim 1, wherein In formula (A), R1 is at least one of -NH2, -CH3NH2, and ; wherein, R6, R7, R8, and R9 are the same or different and each is at least one of H, methyl, and ethyl; wherein, in formula (B), R2, R3, R4, and R5 are the same or different and are each at least one of H, OH, methyl, and ethyl; 3. The scorch retarder according to claim 1 or 2, wherein The molar ratio of the content of the monomer represented by formula (A) to the content of the monomer represented by formula (B) is 1:(2 - 4); and / or, the scorch retarder comprises structural units provided by 3-[(4-phenylaminophenyl)amino]-2-hydroxypropyl methacrylate and structural units provided by trimethylolpropane trimethacrylate; and / or, the weight-average molecular weight of the scorch retarder is 100,000 - 400,000.

4. The preparation method of the scorch retarder according to any one of claims 1-3, characterized in that, The preparation method comprises: melt-blending the monomer represented by formula (A) and the monomer represented by formula (B), and pelletizing the obtained blend, and obtaining the scorch retarder after cooling treatment; wherein the molar ratio of the amount of the monomer represented by formula (A) to the amount of the monomer represented by formula (B) is 1:(0.5 - 5).

5. The preparation method according to claim 4, wherein, The molar ratio of the amount of the monomer represented by formula (A) to the amount of the monomer represented by formula (B) is 1:(2 - 4); and / or, the conditions of the melt-blending include: temperature is 100 - 120 °C, rotation speed is 50 - 70 rpm, and time is 10 - 15 min.

6. A scorch retarder prepared by the preparation method according to claim 4 or 5.

7. A composition for preparing a semiconductive shielding material, characterized in that, The composition comprises a scorch retarder, a copolymer matrix, low-density polyethylene, a processing aid, and a crosslinking agent, wherein the scorch retarder is the scorch retarder according to any one of claims 1 - 3 and 6.

8. The composition according to claim 7, wherein Under the conditions of 190 °C and 2.16 kg, the melt index of the low-density polyethylene is 35 - 50 g / 10 min; and / or, the copolymer matrix is selected from one or more of ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and polypropylene; and / or, the processing aid includes one or more of an antioxidant, conductive carbon black, and a lubricating dispersant; and / or, the crosslinking agent is selected from one or more of dicumyl peroxide, di-tert-butylcumyl peroxide, triallyl isocyanurate, vinyltrimethoxysilane, vinyltriethoxysilane, dibutyltin dilaurate, and triallyl cyanurate.

9. The composition according to claim 8, wherein The composition comprises: 0.1 - 4 parts of the scorch retarder; 60 - 100 parts of the copolymer matrix; 5 - 35 parts of the low-density polyethylene; 0.2 - 1.5 parts of the antioxidant; 45 - 90 parts of the conductive carbon black; 1 - 10 parts of the lubricating dispersant; 0.5 - 3 parts of the crosslinking agent.

10. A method for preparing a semi-conductive shielding material using the composition according to any one of claims 7-9, characterized in that, The method described above comprises: (S1) Contact the scorch retardant, copolymer matrix, low density polyethylene and processing aid described in any one of claims 1-3 and 6 and carry out kneading; (S2) Extrude and pelletize the mixture obtained in step (S1) to obtain a premix; (S3) Contact the crosslinking agent and the premix, mix them and then cool to obtain a semi-conductive shielding material.

11. The method according to claim 10, wherein, In step (S1), the conditions for the kneading include: kneading at 100-120 °C for 10-15 min; And / or, in step (S2), the conditions for the mixing include: mixing at 50-80 °C for 5-15 min.

12. A semi-conductive shielding material prepared by the method described in claim 10 or 11.

13. The semiconductive shielding material according to claim 12, wherein, The scorch time of the semi-conductive shielding material under the condition of 110 °C is 5-7 min, preferably 6.5-7 min.

14. An application of the semi-conductive shielding material described in claim 12 or 13 in a submarine cable.

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