Peelable Semiconductor Layer for High-Temperature Cable Stability

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Solution Overview

Problem

Existing electrical cables with peelable semiconductor layers lack sufficient resistance to deformation by mechanical forces at high temperatures, which can lead to structural deformation and impaired functionality.

Innovation Solution

The development of an electrical cable with a semiconductor layer comprising a non-polar ethylene polymer having a Vicat temperature of at least 100°C, combined with a conductive filler, providing enhanced resistance to mechanical deformation while maintaining good peelability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a copolymer of ethylene and vinyl acetate (EVA) is used in the semiconductor layer, then peelability is improved, but resistance to deformation by mechanical forces at high temperature deteriorates

Engineering Contradiction:

ImprovepeelabilityVSAvoidresistance to deformation by mechanical forces at high temperature

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent changes the chemical composition parameters of the polymer by replacing polar groups (vinyl acetate) with non-polar groups, specifically using ethylene copolymers with non-polar comonomers like hexene, octene, or butene. This parameter change maintains peelability while dramatically improving resistance to deformation at high temperatures, as the non-polar structure provides better thermal stability without sacrificing the necessary peeling characteristics.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite semiconductor layer by combining non-polar ethylene polymer with specific comonomers (hexene, octene, butene) and conductive fillers. This composite approach allows the material to exhibit both the peelability needed for semiconductor layer removal and the enhanced mechanical strength required to resist deformation at operating temperatures up to 90°C or higher.

Inventive Principle:

Principle #40Composite materials

2Strength

If the Vicat temperature of the polymer is increased to improve high temperature resistance, then resistance to deformation is improved, but peelability may deteriorate

Engineering Contradiction:

Improveresistance to deformationVSAvoidpeelability

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The patent carefully selects comonomer content parameters to achieve the optimal balance. By limiting the comonomer content to specific ranges (e.g., 0.1-10 mol% for hexene, 0.1-5 mol% for octene), the patent raises the Vicat temperature sufficiently for high-temperature resistance while maintaining the polymer's ability to peel. The precise control of these compositional parameters ensures both high-temperature stability and operational peelability.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3544025A1Electric cable including an easily peelable polymer layer

Publication Date: 2019.09.25 NEXANS SA

Figure 1

AI summary

The present invention relates to an electrical cable (1) comprising at least one elongated electrical conductor (2), an electrically insulating layer (4) surrounding the elongated electrical conductor (2), and a semiconducting layer (5) surrounding the electrically insulating layer (4), the semiconducting layer (5) comprising at least one conductive charge, characterized in that the semiconducting layer comprises at least one non-polar ethylene polymer having a Vicat temperature, according to ISO 306, of at least 100°C.