CN-121799000-B - Composite layer material for cable intermediate joint and preparation method thereof

CN121799000BCN 121799000 BCN121799000 BCN 121799000BCN-121799000-B

Abstract

The invention belongs to the technical field of power engineering, and particularly relates to a composite layer material for a cable intermediate joint and a preparation method thereof. The composite layer material for the cable intermediate joint comprises an inner semi-conductive layer, an insulating layer and an outer semi-conductive layer, wherein the insulating layer comprises methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, trifluoropropyl methyl vinyl silicone rubber, a vulcanizing agent, a crosslinking aid, an accelerator, diphenyl silicon glycol, an anti-aging agent, trifluoropropyl cage-type silsesquioxane, and a mixture of modified nano hydroxyapatite and nano hectorite. The three layers of the composite layer material for the cable intermediate joint adopt the same siloxane main chain structure and a vulcanization system, ensure the chemical compatibility between layers and realize synchronous co-crosslinking, and ensure the prepared composite layer material for the cable intermediate joint to have excellent mechanical and hydrophobic water blocking properties by adjusting the composition and the proportion of the silicone rubber of each layer.

Inventors

WEI KAI
Sun Guanyue
SUN XIAOWEI
LENG XUEBING
GE WANGQUAN

Assignees

山东七星电气科技发展有限公司

Dates

Publication Date: 20260508
Application Date: 20260310

Claims (10)

1. The composite layer material for the cable intermediate joint is characterized by comprising, by weight, 64-66 parts of methyl vinyl silicone rubber, 26-28 parts of vinyl hyperbranched polysiloxane, 6-10 parts of trifluoropropyl methyl vinyl silicone rubber, 22-24 parts of modified acetylene black, 1.0 part of vulcanizing agent, 1.8 parts of auxiliary crosslinking agent, 0.4 part of accelerator, 0.8-1.0 part of interface compatilizer and 0.8-1.0 part of anti-aging agent, wherein the inner semiconductive layer comprises an inner semiconductive layer, an insulating layer and an outer semiconductive layer; The insulating layer consists of 86-88 parts of methyl vinyl silicone rubber, 6-8 parts of methyl phenyl vinyl silicone rubber, 4-8 parts of trifluoropropyl methyl vinyl silicone rubber, 1.0 part of vulcanizing agent, 1.8 parts of auxiliary cross-linking agent, 0.4 part of accelerator, 2-4 parts of diphenyl silicon glycol, 0.8-1.0 part of antioxidant, 5-7 parts of trifluoropropyl cage-type silsesquioxane and 14-16 parts of mixture of modified nano hydroxyapatite and nano hectorite; The outer semiconductive layer consists of, by weight, 54-56 parts of methyl vinyl silicone rubber, 9-11 parts of methyl phenyl vinyl silicone rubber, 24-26 parts of vinyl hyperbranched polysiloxane, 9-11 parts of trifluoropropyl methyl vinyl silicone rubber, 29-31 parts of modified acetylene black, 1.0 part of vulcanizing agent, 1.8 parts of auxiliary cross-linking agent, 0.4 part of accelerator, 0.8-1.0 part of interface compatilizer, 0.6-0.8 part of release agent and 0.8-1.0 part of anti-aging agent.
2. The composite layer material for cable intermediate joints according to claim 1, wherein the inner semiconductive layer and the outer semiconductive layer are the same as each other in interfacial compatibilizer which is vinyltris (2-methoxyethoxy) silane; the release agent in the outer semiconductive layer is zinc stearate; The vulcanizing agents in the inner semiconductive layer, the insulating layer and the outer semiconductive layer are the same, and the vulcanizing agent is 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane; The auxiliary cross-linking agent in the inner semi-conductive layer, the insulating layer and the outer semi-conductive layer is the same, and the auxiliary cross-linking agent is triallyl isocyanurate; The accelerators in the inner semi-conductive layer, the insulating layer and the outer semi-conductive layer are the same, and the accelerators are N, N' -m-phenylene bismaleimide; The inner semiconductive layer, the insulating layer and the outer semiconductive layer are the same as one another in terms of an anti-aging agent, which is 4,4' -bis (alpha, alpha-dimethylbenzyl) diphenylamine.
3. The composite layer material for the cable intermediate joint according to claim 1, wherein the inner semiconductive layer and the modified acetylene black in the outer semiconductive layer are the same, and the preparation method of the modified acetylene black comprises the steps of mixing ① absolute ethyl alcohol and deionized water uniformly, adding acetic acid to adjust the pH value of a system to be 4.5, adding KH-570 silane coupling agent, stirring and reacting for 40min at room temperature to obtain hydrolysate, adding ② acetylene black into the hydrolysate, performing ultrasonic dispersion for 20min, then performing mechanical stirring for 20min, heating to 80 ℃ and reflux for 4h, performing suction filtration after ③ reaction is completed, washing 3 times by absolute ethyl alcohol, performing vacuum drying for 12h at 80 ℃, and grinding and sieving by a 300-mesh sieve to obtain the modified acetylene black.
4. The composite layer material for cable intermediate joints according to claim 3, wherein the mass ratio of KH-570 silane coupling agent, absolute ethyl alcohol and deionized water in the preparation method step ① of the modified acetylene black is 5:90:10; In the preparation method of the modified acetylene black, the mass ratio of KH-570 silane coupling agent to the acetylene black in the step ② is 5:100.
5. The composite layer material for the cable intermediate joint according to claim 1, wherein the preparation method of the mixture of the modified nano-hydroxyapatite and the nano-hectorite in the insulating layer comprises the steps of ① uniformly mixing absolute ethyl alcohol and deionized water, adding acetic acid to adjust the pH value of a system to be 4.5, adding hexadecyl trimethoxy silane, stirring at room temperature for reaction for 3.5 hours to prepare hydrolysate, ② simultaneously adding the nano-hydroxyapatite and the nano-hectorite into the hydrolysate, performing ultrasonic dispersion for 20 minutes, mechanically stirring for 30 minutes, heating to 80 ℃ for reflux reaction for 3 hours, performing suction filtration after ③ reaction is finished, washing 3 times by absolute ethyl alcohol, vacuum drying for 12 hours at 100 ℃, and grinding and sieving by a 300-mesh sieve to prepare the mixture of the modified nano-hydroxyapatite and the nano-hectorite.
6. The composite layer material for cable intermediate joints according to claim 5, wherein the mass ratio of the modified nano-hydroxyapatite to the nano-hectorite mixture in the preparation method step ① is 72:8:20; The mass of hexadecyltrimethoxysilane in the step ① of the preparation method of the mixture of the modified nano-hydroxyapatite and the nano-hectorite accounts for 3% of the sum of the mass of the nano-hydroxyapatite and the nano-hectorite in the step ②; In the step ② of the preparation method of the mixture of the modified nano-hydroxyapatite and the nano-hectorite, the mass ratio of the nano-hydroxyapatite to the nano-hectorite is 2:1.
7. A method for preparing a composite layer material for a cable intermediate joint according to claim 1, which is characterized by comprising the following steps: (1) Respectively adding the inner semiconductive layer raw material, the insulating layer raw material and the outer semiconductive layer raw material into an internal mixer for mixing and plasticizing to prepare an inner semiconductive layer sizing material, an insulating layer sizing material and an outer semiconductive layer sizing material; (2) Respectively adding the inner semiconductive layer sizing material, the insulating layer sizing material and the outer semiconductive layer sizing material into three plasticizing charging barrels of a three-layer coinjection machine for plasticizing respectively, then sequentially injecting the sizing materials into the same mold cavity from the three charging barrels according to the sequence of the inner semiconductive layer, the insulating layer and the outer semiconductive layer, and carrying out pressure maintaining vulcanization after all three layers are injected; (3) After vulcanization is completed, performing pressure relief, cooling and demolding to prepare a semi-finished product of the composite material for the cable intermediate joint; (4) And (3) placing the semi-finished product of the composite material for the cable intermediate joint in an oven for two-stage vulcanization to prepare the composite layer material for the cable intermediate joint.
8. The method for preparing the composite layer material for the cable intermediate joint according to claim 7, wherein the mixing temperature of the inner semiconductive layer raw material in the step (1) in an internal mixer is 95-97 ℃, and the mixing time is 15-17min; In the step (1), the mixing temperature of the insulating layer raw materials in an internal mixer is 103-105 ℃ and the mixing time is 21-23min; In the step (1), the mixing temperature of the raw materials of the outer semiconductive layer in an internal mixer is 95-97 ℃ and the mixing time is 15-17min.
9. The method for producing a composite layer material for cable intermediate joints according to claim 7, wherein the mold used in the injection in the step (2) is preheated to 173 ℃ and vacuumized to a pressure of-0.09 MPa; in the step (2), the plasticizing temperature of the three plasticizing cylinders is the same when independent plasticizing is carried out, and the plasticizing temperature is 80 ℃; the injection pressure of the inner semiconductive layer sizing material in the step (2) is 90MPa, the injection time is 7s, and the mold temperature is 173 ℃; the injection pressure of the insulating layer sizing material in the step (2) is 110MPa, the injection time is 13s, and the temperature of the die is 173 ℃; the injection pressure of the outer semiconductive layer sizing material in the step (2) is 90MPa, the injection time is 7s, and the mold temperature is 173 ℃; The pressure of the pressure-maintaining vulcanization in the step (2) is 105MPa, the pressure-maintaining vulcanization time is 20min, and the die temperature is 173 ℃.
10. The method for producing a composite layer material for cable intermediate joints according to claim 7, wherein in the step (3), the mold is opened and released after cooling to 85-88 ℃ at a rate of 8 ℃ per minute; the temperature of the secondary vulcanization in the step (4) is 200 ℃, and the secondary vulcanization time is 5h.

Description

Composite layer material for cable intermediate joint and preparation method thereof Technical Field The invention belongs to the technical field of power engineering, and particularly relates to a composite layer material for a cable intermediate joint and a preparation method thereof. Background The middle joint of the power cable is a core accessory for realizing connection, insulation recovery and sealing protection of cable conductors in a power grid transmission line and consists of a conductor connecting part, an insulation shielding system and a peripheral sealing part, wherein the conductor connecting part is a core conductive part of the joint and is used for realizing electric connection (usually a crimping terminal structure) of two sections of cable conductors and is a conductive foundation of the whole joint; the insulating shielding system is a functional core layer coated on the outer side of a conductor connecting part, is concentrically coated and distributed from inside to outside by taking the conductor connecting part as a center, and consists of an inner semiconductive layer, an insulating layer and an outer semiconductive layer, wherein the inner semiconductive layer is directly coated on the periphery of the conductor connecting part and is an innermost layer, realizes a semiconductive function by adding conductive carbon black, and has the effect of homogenizing a conductor surface electric field to avoid electric field concentration, the insulating layer is positioned between the inner semiconductive layer and the outer semiconductive layer and is an intermediate layer and is a core layer for bearing high-voltage insulating isolation, the outer semiconductive layer is coated on the periphery of the insulating layer and is an outermost layer, the semiconductive function is realized by adding conductive carbon black, and has the effect of homogenizing an external electric field and realizing grounding shielding, the three layers adopt the same silicone rubber matrix material system, are prepared into a continuous gapless integral structure by a synchronous vulcanization process after integral injection molding, are cores for guaranteeing the insulating performance of a joint, and the outer periphery sealing part is an insulating sleeve sleeved on the outer side of the insulating shielding system and realizes the integral peripheral sealing of the joint by self elasticity, but does not participate in the insulating shielding function. However, due to the limitation of material characteristics, the three-layer structure is also a main channel for water vapor to invade the inside of the joint, and the specific reasons are that the conventional silicon rubber materials of the inner semi-conductive layer, the insulating layer and the outer semi-conductive layer are limited in hydrophobic property, external water vapor can slowly permeate to the periphery of a conductor connecting part through pores of the three-layer material body, and in addition, although the three layers are integrally vulcanized and formed, the conventional silicon rubber materials are insufficient in interfacial compatibility, microscopic interfacial defects are easy to form, and meanwhile, the uneven dispersion of conductive carbon black in the semi-conductive layer can further aggravate the generation of interfacial pores, and the defects become additional channels for rapid permeation of water vapor. Therefore, there is a need to develop new silicone rubber-based composite layer materials with excellent hydrophobic properties and interfacial compatibility. Disclosure of Invention The invention aims to provide a composite layer material for a cable intermediate joint, which has excellent hydrophobicity and interface compatibility, and a preparation method thereof. The composite layer material for the cable intermediate joint comprises, by weight, 64-66 parts of methyl vinyl silicone rubber, 26-28 parts of vinyl hyperbranched polysiloxane, 6-10 parts of trifluoropropyl methyl vinyl silicone rubber, 22-24 parts of modified acetylene carbon black, 1.0 part of vulcanizing agent, 1.8 parts of auxiliary crosslinking agent, 0.4 part of accelerator, 0.8-1.0 part of interface compatilizer and 0.8-1.0 part of anti-aging agent, wherein the inner semiconductive layer comprises an inner semiconductive layer, an insulating layer and an outer semiconductive layer; The insulating layer consists of 86-88 parts of methyl vinyl silicone rubber, 6-8 parts of methyl phenyl vinyl silicone rubber, 4-8 parts of trifluoropropyl methyl vinyl silicone rubber, 1.0 part of vulcanizing agent, 1.8 parts of auxiliary cross-linking agent, 0.4 part of accelerator, 2-4 parts of diphenyl silicon glycol, 0.8-1.0 part of antioxidant, 5-7 parts of trifluoropropyl cage-type silsesquioxane and 14-16 parts of mixture of modified nano hydroxyapatite and nano hectorite; The outer semiconductive layer consists of, by weight, 54-56 parts of methyl vinyl silico