Semiconductive Composite Using Ultra-Low-Wettability Carbon Black

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Solution Overview

Problem

High contents of carbon black in semiconductive composite materials for medium- to extra-high voltage electrical power cables lead to unwanted moisture uptake, while low contents result in high volume resistivity and lack of electrical percolation, necessitating a balance that existing technologies fail to achieve without compromising electrical properties.

Innovation Solution

A semiconductive composite material comprising a polar organic copolymer and an electrical conducting effective amount of ultra-low-wettability carbon black, characterized by specific surface area and moisture uptake properties, is developed to maintain desirable electrical properties without resorting to immiscible polar and non-polar polymers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high contents of carbon black are used in semiconductive composite materials, then electrical conductivity is improved, but moisture uptake increases

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmoisture uptake
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the surface energy parameters of carbon black by selecting specific types (Vulcan XC-72, Vulcan XC-50, or Acetylene Black) with controlled surface area and surface energy characteristics. This parameter optimization allows achieving adequate electrical conductivity while reducing moisture uptake compared to conventional carbon blacks.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining carbon black with specific polymer matrices (polyethylene, polypropylene, or their copolymers). The composite structure allows optimizing the distribution and dispersion of carbon black particles, achieving electrical conductivity without excessive moisture uptake by controlling the composite morphology and phase distribution.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If low contents of carbon black are used in semiconductive composite materials, then moisture uptake is reduced, but volume resistivity becomes too high and electrical percolation is lost

Engineering Contradiction:
Improvemoisture uptakeVSAvoidelectrical conductivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent optimizes carbon black parameters including surface area (35-190 m²/g), surface energy, and particle size distribution to maximize conductivity efficiency. This allows achieving adequate electrical percolation at lower carbon black loadings, thereby reducing moisture uptake while maintaining electrical functionality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent ensures uniform dispersion and local concentration of carbon black particles within the polymer matrix, creating conductive pathways efficiently. This local quality optimization allows achieving electrical percolation threshold at lower overall carbon black content, reducing moisture uptake while maintaining conductivity.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves a balanced carbon black content that reduces moisture uptake and maintains low volume resistivity, ensuring effective electrical conductivity and percolation, even at lower carbon black loadings, thereby enhancing the performance of semiconductive layers in power cables.

Implementation Method 1

an ultra-low-wettability carbon black which has a Brunauer-Emmett-Teller (BET) nitrogen surface area of from 35 to 190 square meters per gram (m2/g), measured by the BET Nitrogen Surface Area Test Method; and an oil absorption number (OAN) of from 115 to 180 milliliters of oil per 100 grams (mL/100 g) (115 to 180 cubic centimeters per 100 grams (cc/100 g)), measured by the Oil Absorption Number Test Method

Methodology Applied
Scientific EffectHydrophobicity: Hydrophobe

Data Source

PatentUS11732119B2Composite of polar organic polymer and ultralow-wettability carbon black
Publication Date: 2023.08.22 ROHM & HAAS CO

AI summary

A semiconductive composite material consisting essentially of a polar organic copolymer and an electrical conducting effective amount of an ultra-low-wettability carbon black. Also a method of making the composite material; a crosslinked polyethylene product made by curing the composite material; manufactured articles comprising a shaped form of the inventive composite material or product; and methods of using the inventive composite material, product, or articles.