A cross-linking agent, co-cross-linking agent compound system and a high-voltage submarine cable long-time extruded semi-conductive shielding material using the same

Abstract

The present invention relates to the technical field of power cable materials, and discloses a crosslinking agent, a co-crosslinking agent compound system, and a long-time extruded semi-conductive shielding material for high-voltage submarine cables using the same. The composition comprises a matrix resin, conductive carbon black, a processing aid, an active co-crosslinking agent represented by formula (1), a solid crosslinking agent containing a phenyl group and / or an ester group, and a liquid alkyl peroxide crosslinking agent. The semi-conductive shielding material is applied to a submarine cable to solve the problem of frosting on the surface of the shielding layer of the submarine cable product and to prolong the scorch time of the semi-conductive shielding material. #imgabs0#, formula (1); R1 is selected from at least one of #imgabs1#, #imgabs2#, #imgabs3#, #imgabs4#, and #imgabs5#; R3 is selected from a C1-C5 alkyl group; R2 is selected from at least one of a C1-C5 alkyl group, #imgabs6#, #imgabs7#, and #imgabs8#; wherein R is selected from a C1-C5 alkyl group.

Description

Technical Field

[0001] The present invention relates to the technical field of power cable materials, and in particular to a cross-linking agent and a co-cross-linking agent compound system and a long-time extruded semi-conductive shielding material for high-voltage submarine cables using the same. Background Art

[0002] Submarine cables, also known as submarine cables, are cables laid inside or on the seabed, with the transmission medium encased in dense insulating material. Based on their function, submarine cables can be divided into power cables and communication cables. Power cables are primarily used for power transmission in projects like offshore wind power and have shorter installation distances. Communication cables, on the other hand, connect communications between countries and regions, with a range and length far exceeding that of power cables. The structure of a submarine cable, from the inside out, consists of a water-blocking conductor (usually a copper rod), a conductor shield, an insulating material layer, an insulating shield layer, a buffering water-blocking layer, a sheath, an armor layer, and an outer sheath. The inner and outer semi-conductive shielding layers (i.e., the conductor shield and the insulating shield) are essential components of high-voltage AC / DC submarine cables, eliminating defects at the interface between the cable insulation and the conductor / metal shield and ensuring a uniform electric field. Existing semi-conductive shielding materials are composed of a base resin, conductive fillers, crosslinkers / crosslinking aids, and processing aids. The crosslinker and crosslinking aids have a direct impact on the crosslinking properties of the shielding material, such as scorch time, crosslinking time, and crosslinking degree. For high-voltage submarine cables, the longer they are, the fewer joints they require, making them easier to lay in offshore power generation and transmission projects. Therefore, shielding materials used in high-voltage submarine cables are typically required to exhibit slow scorching, fast cross-linking, and continuous, long-term stable extrusion. Furthermore, cross-linking byproducts are a common problem with shielding materials, both domestically and internationally. This can lead to surface frosting after molding, hindering the long-term, stable operation of submarine cables.

[0003] Therefore, it is of great research significance and value to develop a new cross-linking agent and co-cross-linking agent compound system to regulate the scorching and cross-linking characteristics of shielding materials while solving the problems of precipitation and frosting of cross-linking by-products. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem of frosting on the surface of shielding materials and the relatively short scorching time of shielding materials in the prior art. A cross-linking agent and a co-cross-linking agent compound system and a high-voltage submarine cable long-time extruded semi-conductive shielding material using the same are provided. The semi-conductive shielding material is applied to the submarine cable, which can solve the problem of frosting on the surface of the shielding layer of the submarine cable product and prolong the scorching time of the semi-conductive shielding material.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a composition for preparing a semiconductive shielding material, wherein the composition comprises a base resin, conductive carbon black, a processing aid, an active auxiliary crosslinking agent having a structure represented by formula (1), a solid crosslinking agent containing a phenyl group and / or an ester group, and a liquid alkyl peroxide crosslinking agent;

[0006] , formula (1);

[0007] Wherein, in formula (1), R1 is selected from 、 、 、 、 One or more of; wherein, R3 is selected from C1-C5 alkyl;

[0008] R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl.

[0009] A second aspect of the present invention provides a method for preparing a semiconductive shielding material using the aforementioned composition, wherein the method comprises:

[0010] (S1) contacting a base resin, a conductive filler, a processing aid, and an active co-crosslinking agent represented by formula (1), mixing, extruding, and granulating to obtain semi-finished shielding material particles;

[0011] , formula (1);

[0012] Wherein, in formula (1), R1 is selected from 、 、 、 、 One or more of; wherein, R3 is selected from C1-C5 alkyl;

[0013] R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl;

[0014] (S2) premixing a liquid alkyl peroxide crosslinking agent with a solid peroxide crosslinking agent containing a phenyl group and / or an ester group to obtain a composite crosslinking agent;

[0015] (S3) contacting the composite cross-linking agent with the semi-finished shielding material particles, mixing them, and allowing them to stand to obtain a semi-conductive shielding material.

[0016] The third aspect of the present invention provides a semiconductive shielding material prepared by the above-mentioned method.

[0017] A fourth aspect of the present invention provides an application of the aforementioned semi-conductive shielding material in a submarine cable.

[0018] Through the above technical solution, the beneficial effects of the present invention are as follows:

[0019] (a) The present invention adopts a compounding method of a liquid alkyl peroxide crosslinking agent, a solid peroxide crosslinking agent containing a phenyl group and / or an ester group, and an active auxiliary crosslinking agent having a structure represented by formula (1). On the one hand, the liquid alkyl peroxide is introduced to reduce the content of the solid peroxide without reducing the crosslinking efficiency, thereby reducing the production of aromatic alcohol or aromatic ketone by-products with poor compatibility with the matrix resin; on the other hand, the active auxiliary crosslinking agent having a structure represented by formula (1) reacts with the matrix resin to enhance the polarity of the matrix resin and improve the solubility of the crosslinking by-products in the matrix resin; the present invention applies the semi-conductive shielding material to submarine cables, which can solve the problem of blooming on the surface of the shielding layer of submarine cable products.

[0020] (b) The present invention uses an active co-crosslinking agent having a structure represented by a specific formula (1) to consume free radicals generated at low temperatures and delay the occurrence of the crosslinking reaction; the present invention applies the semi-conductive shielding material to submarine cables, which can increase the scorch time of the shielding material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic flow chart of the preparation method of the semi-conductive shielding material provided by the present invention. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0023] As mentioned above, the first aspect of the present invention provides a composition for preparing a semiconductive shielding material, wherein the composition comprises a base resin, conductive carbon black, a processing aid, an active co-crosslinking agent having a structure represented by formula (1), a solid crosslinking agent containing a phenyl group and / or an ester group, and a liquid alkyl peroxide crosslinking agent;

[0024] , formula (1);

[0025] Wherein, in formula (1), R1 is selected from 、 、 、 、 One or more of; wherein, R3 is selected from C1-C5 alkyl;

[0026] R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl.

[0027] According to the present invention, preferably, in formula (1):

[0028] R1 is selected from and / or ; Wherein, R3 is selected from C1-C3 alkyl;

[0029] R2 is selected from C1-C3 alkyl and / or .

[0030] According to the present invention, preferably, R is selected from C1-C3 alkyl groups.

[0031] According to the present invention, more preferably, the active co-crosslinking agent can be selected from one or more of propylene and acrylate auxiliary agents. More preferably, the active co-crosslinking agent is selected from:

[0032] Trimethylolpropane trimethacrylate (TMPTA), the structural formula is:

[0033] and / or,

[0034] Triallyl cyanurate (also known as triallyl cyanurate) has the structural formula:

[0035] .

[0036] The inventors of the present invention have found that the problem of frosting on the surface of shielding materials can be solved by compounding a liquid alkyl peroxide crosslinking agent, a solid peroxide crosslinking agent containing phenyl groups and / or ester groups, and an active auxiliary crosslinking agent having a structure represented by formula (1), while also having the effect of extending the scorching time of the shielding materials.

[0037] Furthermore, the cross-linking by-products of solid peroxides containing phenyl and / or ester groups are aromatic alcohols or aromatic ketones, which have poor compatibility with the matrix resin and are easily precipitated to produce white crystals; the cross-linking by-products of liquid alkyl peroxides are small molecular alkanes or alcohols, which have good compatibility with the matrix resin and do not produce precipitates; the introduction of liquid alkyl peroxides can reduce the content of solid peroxide cross-linking agents containing phenyl and / or ester groups without reducing the cross-linking efficiency, thereby reducing cross-linking by-products such as aromatic alcohols or aromatic ketones; in addition, the active auxiliary cross-linking agents of the acrylate type react with free radicals to form polymer side chains, which on the one hand consume free radicals and inhibit the burning of the shielding material, and on the other hand enhance the polarity of the matrix resin, increase the solubility of the cross-linking by-products in the matrix resin, and alleviate the blooming phenomenon.

[0038] In the present invention, it should be noted that: "frosting phenomenon" refers to the phenomenon that white powdery crystals are precipitated on the surface of the product as time goes by during storage, which affects the apparent properties of the cable product and has a certain impact on the long-term operation stability of the cable.

[0039] "Scorch" is the accumulation of heat and time effects on shielding materials. It is a premature vulcanization phenomenon that will cause difficulties in cable processing, damage the surface smoothness and flatness of the shielding layer and the shielding performance, and even cause uneven "scarring" of the shielding layer, affecting the long-term extrusion of cable production.

[0040] According to the present invention, the solid crosslinking agent containing phenyl groups and / or ester groups has a structure shown in formula (2) and / or a structure shown in formula (3);

[0041] , formula (2); , formula (3);

[0042] Among them, in formula (2), R4 is and / or ;

[0043] R5, R6, R7, R8, R9, R 10 Each is independently selected from one or more C1-C4 alkyl groups.

[0044] In formula (3), R 11 and R 12 Same or different, selected from H and / or ;

[0045] Among them, R 13 an alkyl group selected from C1-C3, 、 One or more of .

[0046] According to the present invention, preferably, the solid crosslinking agent containing phenyl groups and / or ester groups is selected from at least one of the solid crosslinking agents having the following structures:

[0047] Bis(tert-butylperoxyisopropyl)benzene (BIBP), the structural formula is:

[0048] ;

[0049] Dicumyl peroxide (DCP), the structural formula is:

[0050] ;

[0051] 4,4-di(tert-butylperoxy)valerate n-butyl ester (V-40), the structural formula is:

[0052] .

[0053] According to the present invention, the liquid alkyl peroxide cross-linking agent has a structure shown in formula (4) and / or a structure shown in formula (5);

[0054] , formula (4); , formula (5);

[0055] In formula (4), R 14 is a C2-C6 alkylene group, a C2-C6 alkynylene group, 、 One or more of R 15 and R 16 Each independently selected from tert-butyl ( ), benzoate group ( )、2-ethylhexyl carbonate ( ) one or more;

[0056] Among them, in formula (5), R 17 and R 18 Each independently selected from tert-butyl ( ), benzoate group ( )、2-ethylhexyl carbonate ( ) one or more.

[0057] According to the present invention, preferably, the liquid alkyl peroxide crosslinking agent is selected from at least one of the following compounds:

[0058] Di-tert-butyl peroxide, the structural formula is: ;

[0059] 2,5-di-tert-butylperoxy-2,5-dimethylhexane (2,5-di-tert-butylperoxy-2,5-dimethylhexane), the structural formula is:

[0060] ;

[0061] 2,5-Dimethyl-2,5-di-tert-butylperoxy-3-hexyne (hexyne dipentadienyl), the structural formula is:

[0062] .

[0063] According to the present invention, the processing aid includes one or more of a dispersant, an antioxidant and a lubricant.

[0064] According to the present invention, the dispersant is selected from one or more of microcrystalline wax, polyethylene wax, white oil and silicone masterbatch.

[0065] According to the present invention, the antioxidant is selected from one or more of 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMQ), antioxidant 1010 and antioxidant 300.

[0066] According to the present invention, the lubricant is selected from one or more of zinc stearate, ethylene bis stearamide and pentaerythritol.

[0067] According to the present invention, the composition comprises: 55-75 parts of the base resin, 19-40 parts of the conductive carbon black, 0.2-1 parts of the active co-crosslinking agent, 0.5-2 parts of the solid crosslinking agent, 0.3-1 parts of the liquid alkyl crosslinking agent, 0.2-2 parts of the dispersant, 0.2-2 parts of the antioxidant, and 0.2-2 parts of the lubricant; preferably, the composition comprises: 55-64 parts of the base resin, 30-40 parts of the conductive carbon black, 0.5-1 parts of the active co-crosslinking agent, 1-1.5 parts of the solid crosslinking agent, 0.5-1 parts of the liquid alkyl crosslinking agent, 0.5-1 parts of the dispersant, 0.5-1 parts of the antioxidant, and 1-1.5 parts of the lubricant.

[0068] In the present invention, the total weight of the composition for preparing the semiconductive shielding material is 100 parts, that is, the total weight of each component included in the composition is 100 parts. In addition, in the present invention, "parts" is equivalent to "parts by weight".

[0069] According to the present invention, the matrix resin is selected from one or more polyolefin resin copolymers such as ethylene-butyl acrylate (wherein the butyl acrylate content is 10-20wt%), ethylene-ethyl acrylate (wherein the ethyl acrylate content is 10-20wt%), ethylene-vinyl acetate copolymer (wherein the vinyl acetate content is 20-30wt%), and ethylene-acrylic acid copolymer (acrylic acid content is 10-20wt%); preferably, the matrix resin is selected from one or more polyolefin resin copolymers such as ethylene-butyl acrylate, ethylene-ethyl acrylate, and ethylene-vinyl acetate copolymer.

[0070] According to the present invention, the average particle size of the conductive carbon black is 30-60 nm, and the BET specific surface area is 200-400 m 2 / g, iodine absorption value is 65-75mg / g, and oil absorption value is 140-200cc / 100g.

[0071] A second aspect of the present invention provides a method for preparing a semiconductive shielding material using the aforementioned composition, wherein the method comprises:

[0072] (S1) contacting a base resin, a conductive filler, a processing aid, and an active co-crosslinking agent represented by formula (1), mixing, extruding, and granulating to obtain semi-finished shielding material particles;

[0073] , formula (1);

[0074] Wherein, in formula (1), R1 is selected from 、 、 、 、 One or more of; wherein, R3 is selected from C1-C5 alkyl;

[0075] R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl;

[0076] (S2) premixing a liquid alkyl peroxide crosslinking agent with a solid peroxide crosslinking agent containing a phenyl group and / or an ester group to obtain a composite crosslinking agent;

[0077] (S3) contacting the composite cross-linking agent with the semi-finished shielding material particles, mixing them, and allowing them to stand to obtain a semi-conductive shielding material.

[0078] According to the present invention, in step (S1), the base resin, conductive filler, processing aid, and active co-crosslinking agent can be mixed in an internal mixer (purchased from Guangdong Lina Industrial Co., Ltd., model LN-F-5L), then extruded using a single-screw extruder (purchased from Guangdong Lina Industrial Co., Ltd., model LN-SLT45) at 140°C, and granulated at room temperature using a wind-stretching method; wherein the mixing conditions include: mixing at 150-170°C for 10-30 minutes; preferably, mixing at 155-165°C for 10-20 minutes. In the present invention, in step (S1), the specific active crosslinking agent of the present invention is used, which can react with free radicals to form polymer branches, on the one hand, consuming free radicals and inhibiting resin scorching, and on the other hand, enhancing the polarity of the base resin, increasing the solubility of crosslinking byproducts in the base resin, and alleviating blooming.

[0079] According to the present invention, in step (S2), a liquid alkyl peroxide crosslinking agent is premixed with a solid peroxide crosslinking agent containing a phenyl group and / or an ester group. Since the solid peroxide crosslinking byproduct is an aromatic alcohol or an aromatic ketone, which has poor compatibility with the matrix resin and is easily precipitated to produce white crystals; the liquid alkyl peroxide crosslinking byproduct is a small molecule alkane or alcohol, which has good compatibility with the matrix resin and does not produce precipitates. The introduction of the liquid alkyl peroxide can reduce the content of the solid peroxide crosslinking agent without reducing the crosslinking efficiency, thereby reducing crosslinking byproducts such as aromatic alcohol or aromatic ketone. In addition, in step (S2), the premixing conditions include: premixing at 40-60°C for 20-40 minutes; preferably, premixing at 50-60°C for 20-30 minutes.

[0080] According to the present invention, in step (S3), the composite cross-linking agent and the semi-finished shielding material particles are contacted and mixed and then allowed to stand so that the semi-finished shielding material particles can absorb the composite cross-linking agent; wherein the standing conditions include: standing at 50-80°C for 2-6 hours; preferably, standing at 50-60°C for 4-6 hours.

[0081] According to a particularly preferred embodiment of the present invention, Figure 1 As shown, Figure 1 The figure is a flow chart of a method for preparing a semi-conductive shielding material provided by the present invention. A method for preparing a semi-conductive shielding material comprises:

[0082] (S1) weighing the raw materials in the composition for preparing the semi-conductive shielding material in parts by weight, adding the base resin, the conductive filler, the processing aid and the active co-crosslinking agent having the structure represented by formula (1) into an internal mixer for mixing to obtain a mixture melt, then extruding the mixture using a single screw, and granulating the mixture using a wind-stretching method to obtain semi-finished shielding material particles;

[0083] (S2) weighing a liquid alkyl peroxide crosslinking agent and a solid peroxide crosslinking agent containing a phenyl group and / or an ester group according to weight fraction, premixing the mixture at 40-60° C. for 20-40 minutes to obtain a uniform composite crosslinking agent;

[0084] (S3) Then, the shielding material semi-finished particles obtained in step (S1) are added to the composite cross-linking agent obtained in step (S2), mixed, and allowed to stand so that the shielding material semi-finished particles absorb the composite cross-linking agent to obtain a semi-conductive shielding material.

[0085] The third aspect of the present invention provides a semiconductive shielding material prepared by the above-mentioned method.

[0086] According to the present invention, the scorch time T10 of the semi-conductive shielding material at 160° C. is ≥310 s, preferably, T10 is ≥350 s.

[0087] A fourth aspect of the present invention provides an application of the aforementioned semi-conductive shielding material in a submarine cable.

[0088] According to the present invention, when the aforementioned semiconductive shielding material is used in submarine cables, the active co-crosslinking agent undergoes free radical polymerization during the low-temperature (80-120°C) extrusion process and is grafted onto the base resin, consuming free radicals generated during extrusion and preventing scorching of the shielding material. During the high-temperature (180-270°C) vulcanization process, the base resin undergoes a cross-linking reaction with the liquid and solid crosslinking agents, forming a stable cable product. The application conditions include: extruding the semiconductive shielding material at a rotation speed of 5-12 rpm and a temperature of 80-120°C, followed by a vulcanization treatment at 180-270°C for 2-6 hours.

[0089] In the present invention, the semi-conductive shielding material can be applied to long-term extrusion of high-voltage submarine cables.

[0090] In the present invention, the semiconductive shielding material is preferably used for direct current.

[0091] The present invention will be described in detail below through examples.

[0092] In the following examples and comparative examples:

[0093] The tensile strength parameters are measured by GB / T 1040.2-2022 method;

[0094] The elongation at break parameter is measured by the GB / T 1040.2-2022 method;

[0095] The resistivity parameters were measured using the GB / T 31838.2-2019 method;

[0096] The scorch time is measured by the GB / T 16584-1996 method;

[0097] Blooming requires testing of the product after vulcanization (or cross-linking). After the vulcanized product is left to stand for a period of time, the white crystals of the cross-linking by-product precipitated on the surface are measured by optical camera method.

[0098] Example 1

[0099] This embodiment is intended to illustrate the semi-conductive shielding material prepared by the present invention.

[0100] The composition for preparing the semiconductive shielding material comprises:

[0101] Ethylene-butyl acrylate (butyl acrylate content is 15wt%) 55 parts; antioxidant 300 1 part; dispersant microcrystalline wax 0.5 parts; lubricant zinc stearate 0.5 parts, ethylene bis stearamide 0.5 parts; solid crosslinking agent BIBP 1 part; liquid alkyl crosslinking agent di-tert-butyl peroxide 1 part; active co-crosslinking agent TMPTA 0.5 parts; conductive carbon black (average particle size 30nm, BET specific surface area 240m 2 / g; iodine absorption value 75mg / g, oil absorption 200cc / 100g) 40 parts.

[0102] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0103] (S1) 40 parts of conductive carbon black, 55 parts of ethylene-butyl acrylate, 1 part of antioxidant 300, 0.5 parts of microcrystalline wax as a dispersant, 0.5 parts of zinc stearate as a lubricant, 0.5 parts of ethylene bisstearamide, and 0.5 parts of an active co-crosslinking agent TMPTA are added into an internal mixer, mixed at a temperature of 170° C. for 10 minutes, extruded using a single screw at 140° C., and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0104] (S2) mixing 1 part of a solid crosslinking agent BIBP and 1 part of a liquid alkyl crosslinking agent di-tert-butyl peroxide at 60° C. for 20 minutes, and mixing them evenly to obtain a composite crosslinking agent;

[0105] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing the semi-conductive shielding material at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0106] Example 2

[0107] This embodiment is intended to illustrate the semi-conductive shielding material prepared by the present invention.

[0108] The composition for preparing the semiconductive shielding material comprises:

[0109] 60 parts of ethylene-ethyl acrylate (with 20 wt% ethyl acrylate); 0.8 parts of antioxidant TMQ; 0.8 parts of dispersant white oil; 0.7 parts of lubricant zinc stearate, 0.5 parts of ethylene bisstearamide; 1.2 parts of solid crosslinking agent 4,4-di(tert-butylperoxy) valerate n-butyl ester, 0.3 parts of liquid alkyl crosslinking agent 2,5-di-tert-butylperoxy-2,5-dimethylhexane; 0.7 parts of active co-crosslinking agent triallyl cyanurate; conductive carbon black (average particle size 40 nm, BET specific surface area 210 m 2 / g; iodine absorption value 70mg / g, oil absorption value 140cc / 100g) 35 parts.

[0110] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0111] (S1) 35 parts of conductive carbon black, 60 parts of ethylene ethyl acrylate, 0.8 parts of antioxidant TMQ, 0.8 parts of dispersant white oil, 0.7 parts of lubricant zinc stearate, 0.5 parts of ethylene bis stearamide, and 0.7 parts of active co-crosslinking agent triallyl cyanurate are added into an internal mixer, mixed at 160° C. for 20 minutes, extruded at 140° C. using a single screw, and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0112] (S2) mixing 1.2 parts of a solid crosslinking agent, 4,4-di(tert-butylperoxy)valerate, and 0.3 parts of a liquid alkyl crosslinking agent, 2,5-di-tert-butylperoxy-2,5-dimethylhexane, at 60° C. for 30 minutes, and mixing until uniform, to obtain a composite crosslinking agent;

[0113] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing the semi-conductive shielding material at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0114] Example 3

[0115] This embodiment is intended to illustrate the semi-conductive shielding material prepared by the present invention.

[0116] The composition for preparing the semiconductive shielding material comprises:

[0117] 64 parts of ethylene-butyl acrylate (butyl acrylate content is 20wt%); 1 part of antioxidant TMQ; 0.5 parts of dispersant silicone masterbatch; 1 part of lubricant pentaerythritol; 1.5 parts of solid crosslinking agent DCP; 1 part of liquid alkyl crosslinking agent 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne; 1 part of active co-crosslinking agent TMPTA; conductive carbon black (average particle size 30nm, BET specific surface area 240m 2 / g; iodine absorption value 75mg / g, oil absorption value 200cc / 100g) 30 parts.

[0118] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0119] (S1) 30 parts of conductive carbon black, 64 parts of ethylene-butyl acrylate, 1 part of antioxidant TMQ, 0.5 parts of dispersant silicone masterbatch, 1 part of lubricant pentaerythritol, and 1 part of active co-crosslinking agent TMPTA are added to an internal mixer, mixed at a temperature of 170° C. for 10 minutes, extruded using a single screw at 140° C., and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0120] (S2) mixing 1.5 parts of a solid crosslinking agent DCP and 1 part of a liquid alkyl crosslinking agent 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne at 40° C. for 40 minutes until uniformly mixed to obtain a composite crosslinking agent;

[0121] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing them at 50°C for 6 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0122] Example 4

[0123] This embodiment is intended to illustrate the semi-conductive shielding material prepared by the present invention.

[0124] The composition for preparing the semiconductive shielding material comprises:

[0125] 70 parts of ethylene-vinyl acetate copolymer (vinyl acetate content: 20 wt%); 1 part of antioxidant 1010; 0.5 parts of polyethylene wax as dispersant; 1 part of pentaerythritol as lubricant; 1.5 parts of BIBP as solid crosslinker; 0.5 parts of 2,5-di-tert-butylperoxy-2,5-dimethylhexane as liquid alkyl crosslinker; 0.5 parts of TMPTA as active co-crosslinker; conductive carbon black (average particle size: 60 nm, BET specific surface area: 400 m 2 / g; iodine absorption value 65mg / g, oil absorption value 150cc / 100g) 25 parts.

[0126] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0127] (S1) adding 25 parts of conductive carbon black, 70 parts of ethylene-vinyl acetate copolymer, 1 part of antioxidant 1010, 0.5 parts of polyethylene wax as a dispersant, 1 part of pentaerythritol as a lubricant, and 0.5 parts of active co-crosslinking agent TMPTA into an internal mixer, mixing at a temperature of 150° C. for 30 minutes, extruding at 140° C. using a single screw, and granulating at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0128] (S2) mixing 1.5 parts of a solid crosslinking agent BIBP and 0.5 parts of a liquid alkyl crosslinking agent 2,5-di-tert-butylperoxy-2,5-dimethylhexane at 60° C. for 20 minutes, and mixing them evenly to obtain a composite crosslinking agent;

[0129] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing the semi-conductive shielding material at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0130] Example 5

[0131] This embodiment is intended to illustrate the semi-conductive shielding material prepared by the present invention.

[0132] The composition for preparing the semiconductive shielding material comprises:

[0133] 70 parts of ethylene-vinyl acetate copolymer (vinyl acetate content is 30wt%), 5 parts of polyolefin resin; 1.2 parts of antioxidant 1010; 0.7 parts of polyethylene wax as dispersant; 1 part of ethylene bisstearamide as lubricant; 2 parts of solid crosslinker BIBP; 0.3 parts of liquid alkyl crosslinker 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne; 0.8 parts of active co-crosslinker triallyl cyanurate; conductive carbon black (average particle size 60nm, BET specific surface area 400m 2 / g; iodine absorption value 65mg / g, oil absorption value 150cc / 100g) 19 parts.

[0134] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0135] (S1) adding 25 parts of conductive carbon black, 75 parts of ethylene-vinyl acetate copolymer, 1.2 parts of antioxidant 1010, 0.7 parts of polyethylene wax as a dispersant, 1 part of ethylene bisstearamide as a lubricant, and 0.8 parts of triallyl cyanurate as an active co-crosslinking agent into an internal mixer, mixing at a temperature of 150° C. for 30 minutes, extruding at 140° C. using a single screw, and granulating at room temperature using a wind-stretching method; obtaining semi-finished shielding material particles;

[0136] (S2) mixing 2 parts of a solid crosslinking agent BIBP and 0.3 parts of a liquid alkyl crosslinking agent 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne at 60° C. for 30 minutes, and mixing until uniform to obtain a composite crosslinking agent;

[0137] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing them at 70°C for 5 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0138] Example 6

[0139] A semiconductive shielding material was prepared in the same manner as in Example 1, except that the "active co-crosslinking agent TMPTA" in Example 1 was replaced by:

[0140]

[0141] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0142] Example 7

[0143] A semiconductive shielding material was prepared in the same manner as in Example 1, except that the "solid crosslinking agent BIBP" in Example 1 was replaced with "1,3-bis(tert-butylperoxyisopropyl)benzene:

[0144] ”;

[0145] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0146] Example 8

[0147] A semiconductive shielding material was prepared in the same manner as in Example 1, except that:

[0148] The "liquid alkyl crosslinking agent di-tert-butyl peroxide" in Example 1 is replaced by "tert-butyl peroxybenzoate: ”;

[0149] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0150] Comparative Example 1

[0151] A semiconductive shielding material was prepared in the same manner as in Example 1, except that the active co-crosslinking agent TMPTA was not added in this comparative example.

[0152] The composition for preparing the semiconductive shielding material in this comparative example includes, by mass:

[0153] 55 parts of ethylene-butyl acrylate; 1 part of antioxidant 300; 0.5 parts of dispersant microcrystalline wax; 0.5 parts of lubricant zinc stearate and 0.5 parts of ethylene bis stearamide; 1.5 parts of solid crosslinking agent BIBP; 1 part of liquid alkyl crosslinking agent di-tert-butyl peroxide; conductive carbon black (average particle size 30nm, BET specific surface area 240m 2 / g; iodine absorption value 75mg / g, oil absorption 200cc / 100g) 40 parts.

[0154] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0155] (S1) 40 parts of conductive carbon black, 55 parts of ethylene-butyl acrylate, 1 part of antioxidant 300, 0.5 parts of microcrystalline wax as a dispersant, 0.5 parts of zinc stearate as a lubricant, and 0.5 parts of ethylene bis(stearamide) were added into an internal mixer, mixed at 170° C. for 10 minutes, extruded using a single screw at 140° C., and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0156] (S2) mixing 1 part of a solid crosslinking agent BIBP and 1 part of a liquid alkyl crosslinking agent di-tert-butyl peroxide at 60° C. for 20 minutes, and mixing them evenly to obtain a composite crosslinking agent;

[0157] (S3) adding the composite cross-linking agent obtained in step (S2) to the semi-finished shielding material particles obtained in step (S1), and absorbing the semi-conductive shielding material at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0158] Comparative Example 2

[0159] A semiconductive shielding material was prepared in the same manner as in Example 1, except that no solid crosslinking agent BIBP was added in this comparative example.

[0160] The composition for preparing the semiconductive shielding material comprises:

[0161] 55 parts of ethylene-butyl acrylate; 1 part of antioxidant 300; 0.5 parts of dispersant microcrystalline wax; 0.5 parts of lubricant zinc stearate and 0.5 parts of ethylene bis stearamide; 2 parts of liquid alkyl crosslinking agent di-tert-butyl peroxide; 0.5 parts of active co-crosslinking agent TMPTA; conductive carbon black (average particle size 30nm, BET specific surface area 240m 2 / g; iodine absorption value 75mg / g, oil absorption 200cc / 100g) 40 parts.

[0162] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0163] (S1) 40 parts of conductive carbon black, 55 parts of ethylene-butyl acrylate, 1 part of antioxidant 300, 0.5 parts of microcrystalline wax as a dispersant, 0.5 parts of zinc stearate as a lubricant, 0.5 parts of ethylene bisstearamide, and 0.5 parts of active co-crosslinking agent TMPTA are added into an internal mixer, mixed at a temperature of 170° C. for 10 minutes, extruded using a single screw at 140° C., and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0164] (S2) adding 2 parts of a liquid alkyl crosslinking agent, di-tert-butyl peroxide, to the semi-finished shielding material particles obtained in step (S1), and absorbing them at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0165] Comparative Example 3

[0166] A semiconductive shielding material was prepared in the same manner as in Example 1, except that the liquid alkyl crosslinking agent di-tert-butyl peroxide was not added in this comparative example.

[0167] The composition for preparing the semiconductive shielding material comprises:

[0168] 55 parts of ethylene-butyl acrylate; 1 part of antioxidant 300; 0.5 parts of dispersant microcrystalline wax; 0.5 parts of lubricant zinc stearate and 0.5 parts of ethylene bis stearamide; 2 parts of solid crosslinking agent BIBP; 0.5 parts of active co-crosslinking agent TMPTA; conductive carbon black (average particle size 30nm, BET specific surface area 240m 2 / g; iodine absorption value 75mg / g, oil absorption 200cc / 100g) 40 parts.

[0169] The method for preparing a semiconductive shielding material for a high-voltage submarine cable using the above-mentioned composition for preparing a semiconductive shielding material comprises the following steps:

[0170] (S1) 40 parts of conductive carbon black, 55 parts of ethylene-butyl acrylate, 1 part of antioxidant 300, 0.5 parts of microcrystalline wax as a dispersant, 0.5 parts of zinc stearate as a lubricant, 0.5 parts of ethylene bisstearamide, and 0.5 parts of an active co-crosslinking agent TMPTA are added into an internal mixer, mixed at a temperature of 170° C. for 10 minutes, extruded using a single screw at 140° C., and granulated at room temperature using a wind-stretching method to obtain semi-finished shielding material particles;

[0171] (S2) adding 2 parts of a solid crosslinking agent BIBP to the semi-finished shielding material particles obtained in step (S1), and absorbing the semi-conductive shielding material at 60°C for 4 hours to obtain a semi-conductive shielding material for standby use (for high-voltage submarine cables).

[0172] Comparative Example 4

[0173] A semiconductive shielding material was prepared in the same manner as in Example 1, except that:

[0174] The "active co-crosslinking agent TMPTA" in Example 1 was replaced by "trimethylolpropane trimethacrylate:

[0175] ”;

[0176] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0177] Comparative Example 5

[0178] A semiconductive shielding material was prepared in the same manner as in Example 1, except that:

[0179] The "solid crosslinking agent BIBP" in Example 1 was replaced by "2,2-dihydroperoxide propane:

[0180] ”;

[0181] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0182] Comparative Example 6

[0183] A semiconductive shielding material was prepared in the same manner as in Example 1, except that:

[0184] The "liquid alkyl crosslinking agent di-tert-butyl peroxide" in Example 1 was replaced with "bis(3,5,5-trimethylhexanoyl) peroxide"

[0185] ( )";

[0186] The method for preparing the semiconductive shielding material for high-voltage submarine cables using the composition for preparing the semiconductive shielding material is the same as that in Example 1; the semiconductive shielding material is obtained for standby use (for high-voltage submarine cables).

[0187] Application Examples

[0188] The semiconductive shielding material prepared in Examples 1-8 and Comparative Examples 1-6 was subjected to hot pressing at 180°C, 15MPa for 30 minutes to prepare cross-linked shielding material samples;

[0189] According to the standards GB / T 1040.2-2022 and GB / T 31838.2-2019, corresponding samples were cut and tested for their mechanical and electrical properties;

[0190] Take the semi-conductive shielding material particles and test their scorch performance according to the standard GB / T 16584-1996;

[0191] The cross-linked shielding material sample prepared by hot pressing was placed at room temperature for 24 hours, and the precipitation of white crystals on the surface was observed.

[0192] The test results are shown in Table 1.

[0193] Table 1

[0194]

[0195] Note: The time when the degree of vulcanization reaches 10% is expressed as T10.

[0196] From the results in Table 1, it can be seen that the present invention adopts a compound of a liquid alkyl peroxide crosslinking agent, a solid peroxide crosslinking agent and an active co-crosslinking agent, which effectively improves the surface blooming phenomenon of shielding material products (such as submarine cables) and increases the scorch time of the shielding material.

[0197] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A composition for preparing a semiconductive shielding material, characterized in that: The composition comprises a base resin, conductive carbon black, a processing aid, an active co-crosslinking agent having a structure represented by formula (1), a solid crosslinking agent containing a phenyl group and / or an ester group, and an alkyl peroxide crosslinking agent; , formula (1); Wherein, in formula (1), R1 is selected from 、 、 、 wherein R3 is selected from a C1-C5 alkyl group; R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl; Wherein, the solid crosslinking agent containing phenyl and / or ester groups is selected from one or more of bis(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, and 4,4-di(tert-butylperoxy)butyl valerate; The alkyl peroxide cross-linking agent is one or more of di-tert-butyl peroxide, 2,5-di-tert-butylperoxy-2,5-dimethylhexane and 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne.

2. The composition according to claim 1, wherein In formula (1), R1 is selected from or ; wherein R3 is selected from a C1-C3 alkyl group; R2 is selected from C1-C3 alkyl and / or .

3. The composition according to claim 2, wherein The active auxiliary cross-linking agent is selected from trimethylolpropane triacrylate and / or triallyl cyanurate.

4. The composition according to any one of claims 1 to 3, wherein The matrix resin is selected from one or more of ethylene-butyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer; And / or, the processing aid includes one or more of a dispersant, an antioxidant and a lubricant: And / or, the average particle size of the conductive carbon black is 30-60 nm.

5. The composition according to claim 4, wherein The dispersant is selected from one or more of microcrystalline wax, polyethylene wax, white oil and silicone masterbatch; and / or, the antioxidant is selected from one or more of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, antioxidant 1010 and antioxidant 300; And / or, the lubricant is selected from one or more of zinc stearate, ethylene bis stearamide and pentaerythritol.

6. The composition according to claim 5, wherein The composition comprises: 55-75 parts of the base resin; 19-40 parts of the conductive carbon black; 0.2-1 part of the active co-crosslinking agent; 0.5-2 parts of the solid crosslinking agent; 0.3-1 part of the alkyl peroxide crosslinking agent; 0.2-2 parts of the dispersant; 0.2-2 parts of the antioxidant; The lubricant is 0.2-2 parts.

7. A method for preparing a semiconductive shielding material using the composition according to any one of claims 1 to 6, characterized in that: The method includes: (S1) contacting a base resin, conductive carbon black, a processing aid, and an active co-crosslinking agent represented by formula (1), mixing, extruding, and granulating to obtain semi-finished shielding material particles; , formula (1); Wherein, in formula (1), R1 is selected from 、 、 、 wherein R3 is selected from a C1-C5 alkyl group; R2 is selected from C1-C5 alkyl, 、 、 One or more of; wherein, R is selected from C1-C5 alkyl; (S2) premixing an alkyl peroxide crosslinking agent with a solid crosslinking agent containing a phenyl group and / or an ester group to obtain a composite crosslinking agent; (S3) contacting the composite cross-linking agent with the semi-finished shielding material particles, mixing them, and allowing them to stand to obtain a semi-conductive shielding material.

8. The method according to claim 7, wherein: In step (S1), the mixing conditions include: mixing at 150-170°C for 10-30 minutes; And / or, in step (S2), the premixing conditions include: premixing at 40-60°C for 20-40 minutes; And / or, in step (S3), the standing condition includes: standing at 50-80°C for 2-6 hours.

9. A semiconductive shielding material prepared by the method according to claim 7 or 8.

10. The semiconductive shielding material according to claim 9, wherein: The scorch time T10 of the semi-conductive shielding material at 160° C. is ≥310s.

11. Use of the semiconductive shielding material according to claim 9 or 10 in a submarine cable.

12. The use according to claim 11, wherein: The application conditions include: extruding the semi-conductive shielding material into a cable at a rotation speed of 5-12 rpm and a temperature of 80-120° C., and vulcanizing the material at 180-270° C. for 2-6 hours.

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