Carbon Nanostructure Preblends for CNT Dispersion in Elastomers

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Solution Overview

Problem

Dispersion of carbon nanotubes in rubber or elastomeric polymers is challenging due to their high viscosity, which hinders the effective reinforcement of these materials, and existing methods do not simultaneously improve modulus and elongation properties.

Innovation Solution

Forming a preblend of carbon nanostructures with carbon black by suspending or dissolving them in a solvent, mixing, and drying to create a dispersion that can be incorporated into the elastomer matrix, enhancing the dispersion and reinforcement of carbon nanotubes within the rubber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If carbon nanotubes are directly mixed into elastomers, then reinforcement is achieved, but the high viscosity of elastomers prevents effective dispersion

Engineering Contradiction:
ImprovereinforcementVSAvoiddispersion
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses a solvent as an intermediary medium to facilitate the dispersion of carbon nanotubes. The CNTs are first dispersed in a solvent to form a slurry, which is then mixed with the elastomer. The solvent acts as a mediator that enables CNT dispersion without requiring direct mixing into the high-viscosity elastomer, thereby resolving the contradiction between reinforcement and ease of manufacture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical state and viscosity parameters by introducing a solvent system. By forming a CNT slurry in solvent before incorporation into elastomer, the effective viscosity during the critical dispersion stage is reduced, enabling better CNT distribution while maintaining the final elastomer's mechanical reinforcement properties.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional mixing methods are used, then processing is simple, but CNT dispersion in elastomer is insufficient

Engineering Contradiction:
Improveprocessing simplicityVSAvoiddispersion quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-dispersing carbon nanotubes in a solvent to create a stable slurry before incorporating it into the elastomer. This preliminary dispersion step ensures uniform CNT distribution in the liquid phase, which then translates to better dispersion in the final elastomer product without requiring complex mixing equipment or procedures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The solvent slurry serves as an intermediary carrier that simplifies the manufacturing process. Instead of directly mixing CNTs into viscous elastomer, the pre-formed slurry can be easily incorporated using standard mixing equipment, maintaining processing simplicity while achieving superior dispersion quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If heat is applied to reduce elastomer viscosity, then mixing becomes easier, but viscosity reduction is insufficient compared to thermoplastics

Engineering Contradiction:
Improvemixing easeVSAvoidviscosity reduction effectiveness
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent introduces a solvent as an intermediary that addresses the viscosity issue without relying on excessive heat. The solvent reduces the effective viscosity during the CNT dispersion stage, enabling easy mixing at lower temperatures while maintaining elastomer integrity, thus resolving the contradiction between mixing ease and temperature requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the viscosity parameter through solvent addition rather than thermal processing alone. By forming a CNT slurry in solvent, the system achieves low-viscosity conditions favorable for mixing without requiring the high temperatures needed for thermoplastics, thereby achieving mixing ease with minimal temperature increase.

Inventive Principle:
Principle #35Parameter changes

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

This method improves the modulus, elongation, and tear properties of the elastomer compositions, allowing for the creation of rubber articles with enhanced mechanical properties such as tires and belts, while being cost-effective and compatible with existing rubber processes.

Implementation Method 1

suspending or dissolving the CNT, or other carbon nanostructured material, in a solvent

Methodology Applied
Scientific EffectSuspension: Suspension

Implementation Method 2

suspending or dissolving the CNT, or other carbon nanostructured material, in a solvent

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

drying to remove the liquid

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3262105B1Method for making carbon nanostructure preblends
Publication Date: 2023.11.08 THE GATES CORP
  • EP3262105B1 patent drawingFigure 1
  • EP3262105B1 patent drawingFigure 2
  • EP3262105B1 patent drawingFigure 3A~3D

AI summary

A method for preparing a "preblend" of nano-structured carbon, such as nanotubes, fullerenes, or graphene, and a particulate solid, such as carbon black, graphitic particles or glassy carbon involving wet-mixing and followed by optional drying to remove the liquid medium. The preblend may be in the form of a core-shell powder material with the nano-structured carbon as the shell on the particulate solid core. The preblend may provide particularly improved dispersion of single-wall nanotubes in ethylene- -olefin elastomer compositions, resulting in improved reinforcement from the nanotubes. The improved elastomer compositions may show simultaneous improvement in both modulus and in elongation at break. The elastomer compositions may be formed into useful rubber articles.