EP-4738395-A1 - PREPARATION METHOD FOR HIGH-VOLTAGE CABLE AND HIGH-VOLTAGE CABLE

EP4738395A1EP 4738395 A1EP4738395 A1EP 4738395A1EP-4738395-A1

Abstract

The present invention provides a preparation method of a high-voltage cable and a high-voltage cable. The preparation method includes: preparing modified polyvinyl chloride, where the modified polyvinyl chloride includes polyvinyl chloride and a filler added to the polyvinyl chloride, and using 100 parts by weight of polyvinyl chloride as a base material, the filler includes the following ingredients in parts by weight: 1-2 parts of polyethylene, 2-3 parts of a filling agent, 2-3 parts of a lubricant and 2-5 parts of a toughening agent; extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath, the modified polyvinyl chloride sheath being bonded to the smooth metal sheath layer; where the smooth metal sheath layer is wrapped around an outer surface of a cable core. The preparation method of a high-voltage cable provided by the present invention can greatly improve the flame retardant performance of high-voltage cable.

Inventors

XIA, Yunhai
HOU, Hongjian
LU, WEI
FU, Changqi
ZHANG, JIANMIN
XIE, Shuhong
XUE, Chi

Assignees

Zhongtian Technology Submarine Cable Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240105

Claims (14)

A preparation method of a high-voltage cable, comprising: preparing modified polyvinyl chloride, wherein the modified polyvinyl chloride comprises polyvinyl chloride and a filler added to the polyvinyl chloride, and with 100 parts by weight of polyvinyl chloride as a base material, the filler comprises the following ingredients in parts by weight: 1-2 parts of polyethylene, 2-3 parts of a filling agent, 2-3 parts of a lubricant and 2-5 parts of a toughening agent; extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath, the modified polyvinyl chloride sheath being bonded to the smooth metal sheath layer; wherein the smooth metal sheath layer is wrapped around an outer surface of a cable core.
The preparation method according to claim 1, wherein the preparing modified polyvinyl chloride specifically comprises: with 100 parts by weight of polyvinyl chloride as the base material, adding the filler, wherein a mass ratio of the polyethylene, the filling agent, the lubricant and the toughening agent in the filler is 1:2:2:4, 1:2:3:3 or 2:3:2:2.
The preparation method according to claim 2, wherein the extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath specifically comprises: extruding and wrapping the modified polyvinyl chloride around the outer surface of the smooth metal sheath layer by an extruder to form the modified polyvinyl chloride sheath; wherein during extrusion process, by adjusting a barrel heating temperature and a head heating temperature of the extruder, the extruder is controlled to reach a melting temperature of the modified polyvinyl chloride when extruding the modified polyvinyl chloride.
The preparation method according to claim 3, wherein the melting temperature of the modified polyvinyl chloride is greater than or equal to 175°C and less than or equal to 185°C; the barrel heating temperature of the extruder is greater than or equal to 160°C and less than or equal to 180°C, and the head heating temperature of the extruder is greater than or equal to 180°C or equal to 200°C.
The preparation method according to any one of claims 1 to 4, wherein before the extruding and wrapping the modified polyvinyl chloride around the outer surface of the smooth metal sheath layer to form the modified polyvinyl chloride sheath, the preparation method further comprises: preparing polyester hot melt adhesive; extruding and wrapping the polyester hot melt adhesive around the outer surface of the smooth metal sheath layer to form a hot melt adhesive layer, wherein the modified polyvinyl chloride sheath is bonded to the smooth metal sheath layer via the hot melt adhesive layer.
The preparation method according to claim 5, wherein the preparing polyester hot melt adhesive specifically comprises: subjecting a thermoplastic polyester to an alcoholysis treatment, an acetification treatment, a heating treatment and a cooling treatment in sequence to form the polyester hot melt adhesive.
The preparation method according to claim 6, wherein the alcoholysis treatment is an alcoholysis performed by adding an alcoholysis solution to the thermoplastic polyester; based on 100 parts by weight of the thermoplastic polyester, the alcoholysis solution comprises the following ingredients in parts by weight: 20 parts of the alcohol solution and 2-3 parts of a first catalyst.
The preparation method according to claim 6, wherein the acetification treatment comprises adding an acidolysis solution to a material that has completed the alcoholysis treatment, and heating until the material in the acetification treatment is completely dissolved; based on 100 parts by weight of the thermoplastic polyester, the acidolysis solution comprises the following ingredients in parts by weight: 80 parts of an acid solution, 4-6 parts of a second catalyst and 2-4 parts of a first antioxidant.
The preparation method according to any one of claims 1 to 4, wherein before the extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath, the preparation method further comprises: preparing an elastic buffer material having semi-conductive property; and extruding and wrapping the elastic buffer material around an outer surface of an insulation shielding layer of the cable core to form a semi-conductive elastomer buffer layer, wherein the semi-conductive elastomer buffer layer is wrapped between the insulation shielding layer and the smooth metal sheath layer.
The preparation method according to claim 9, wherein the preparing an elastic buffer material having semi-conductive property specifically comprises: mixing the following raw materials in parts by weight: 100 parts of elastomer rubber, 20 parts of a rubber-plastic foaming material, 35-40 parts of styrene-butadiene rubber, 25-30 parts of a filling and reinforcing agent, and 2-5 parts of a second antioxidant to prepare the elastic buffer material.
The preparation method according to claim 10, wherein the elastomer rubber is a rubber formed by a copolymer of ethylene, propylene and a non-conjugated diene, the rubber-plastic foaming material is a plastic formed by copolymerization of ethylene and acetic acid, and the filling and reinforcing agent is carbon black.
A high-voltage cable, prepared by the preparation method according to any one of claims 1 to 11, wherein the high-voltage cable comprises a cable core, the cable core has an outer surface wrapped with a smooth metal sheath layer and a sheath in sequence along an axial direction of the cable core, the sheath is a modified polyvinyl chloride sheath, the modified polyvinyl chloride sheath is wrapped around an outer surface of the smooth metal sheath layer and bonded to the smooth metal sheath layer; the modified polyvinyl chloride sheath is prepared from modified polyvinyl chloride, and the modified polyvinyl chloride comprises polyvinyl chloride and a filler added to the polyvinyl chloride; using 100 parts by weight of polyvinyl chloride as a base material, the filler comprises the following ingredients in parts by weight: 1-2 parts of polyethylene, 2-3 parts of a filling agent, 2-3 parts of a lubricant and 2-5 parts of a toughening agent.
The high-voltage cable according to claim 12, further comprising a hot melt adhesive layer, wherein the hot melt adhesive layer is located between the smooth metal sheath layer and the modified polyvinyl chloride sheath to bond the modified polyvinyl chloride sheath and the smooth metal sheath layer; the hot melt adhesive layer is an adhesive layer formed by a polyester hot melt adhesive, and the polyester hot melt adhesive is a polyester adhesive formed by subjecting a thermoplastic polyester to an alcoholysis treatment, an acetification treatment, a heating treatment and a cooling treatment in sequence.
The high-voltage cable according to claim 13, wherein the outer surface of the cable core is also wrapped with a semi-conductive elastomer buffer layer along the axial direction of the cable core, the cable core comprises an insulation shielding layer, and the smooth metal sheath layer is in contact with the insulation shielding layer via the semi-conductive elastomer buffer layer.

Description

The present invention claims priority to Chinese Patent Application No. 202310021812.3, filed with the China National Intellectual Property Administration on January 06, 2023, and entitled "PREPARATION METHOD OF HIGH-VOLTAGE CABLE AND HIGH-VOLTAGE CABLE", which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present invention relates to the technical field of power cables, and in particular, to a preparation method of high-voltage cable and a high-voltage cable. BACKGROUND With the rapid development of cities, high-voltage cables play an important role in the electric power system. At present, the outer surface of the insulation shielding layer of the cable core in a high-voltage cable is usually wrapped with a cushion layer and a metal sheath layer in sequence. In existing high-voltage cables, a corrugated aluminum sheath is mostly adopted as the metal sheath layer. Studies have shown that the structure of the corrugated aluminum sheath has certain defects, which will lead to gap discharge during the finished product testing. In the research and development process of high-voltage cables, the relevant technologies have proposed using a smooth aluminum sheath to replace the existing corrugated aluminum sheath for covering the outer surface of the cushion layer to form a smooth aluminum sheath cable, so as to increase the contact area between the smooth aluminum sheath and the cushion layer, thereby overcoming the gap discharge phenomenon during the finished product testing. However, the existing smooth aluminum sheath cables are difficult to meet the requirements for improved flame retardant performance of high-voltage cables. SUMMARY The present invention provides a preparation method of a high-voltage cable and a high-voltage cable, which can meet the requirements for improving the flame retardant performance of the high-voltage cable. In a first aspect, the present invention provides a preparation method of a high-voltage cable, and the preparation method includes: preparing modified polyvinyl chloride, where the modified polyvinyl chloride includes polyvinyl chloride and a filler added to the polyvinyl chloride, and using 100 parts by weight of polyvinyl chloride as a base material, the filler includes the following ingredients in parts by weight: 1-2 parts of polyethylene, 2-3 parts of a filling agent, 2-3 parts of a lubricant and 2-5 parts of a toughening agent;extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath, the modified polyvinyl chloride sheath being bonded to the smooth metal sheath layer; where the smooth metal sheath layer is wrapped around an outer surface of a cable core. In some optional implementations, the preparing modified polyvinyl chloride specifically includes: with 100 parts by weight of polyvinyl chloride as the base material, adding the filler, where a mass ratio of the polyethylene, the filling agent, the lubricant and the toughening agent in the filler is 1:2:2:4, 1:2:3:3 or 2:3:2:2. In some optional implementations, the extruding and wrapping the modified polyvinyl chloride around an outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath specifically includes: extruding and wrapping the modified polyvinyl chloride around the outer surface of the smooth metal sheath layer by an extruder to form the modified polyvinyl chloride sheath;where during extrusion process, by adjusting a barrel heating temperature and a head heating temperature of the extruder, the extruder is controlled to reach a melting temperature of the modified polyvinyl chloride when extruding the modified polyvinyl chloride. In some optional implementations, the melting temperature of the modified polyvinyl chloride is greater than or equal to 175°C and less than or equal to 185°C; the barrel heating temperature of the extruder is greater than or equal to 160°C and less than or equal to 180°C, and the head heating temperature of the extruder is greater than or equal to 180°C or equal to 200°C. In some optional implementations, before the extruding and wrapping the modified polyvinyl chloride around the outer surface of the smooth metal sheath layer to form the modified polyvinyl chloride sheath, the preparation method further includes: preparing polyester hot melt adhesive;extruding and wrapping the polyester hot melt adhesive around the outer surface of the smooth metal sheath layer to form a hot melt adhesive layer, where the modified polyvinyl chloride sheath is bonded to the smooth metal sheath layer via the hot melt adhesive layer. In some optional implementations, the preparing polyester hot melt adhesive specifically includes: subjecting thermoplastic polyester to an alcoholysis treatment, an acetification treatment, a heating treatment and a cooling treatment in sequence to form the polyester hot melt adhesive. In some optional implementations