Crosslinked Lignin Particles With High Surface Area for Rubber Fillers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing lignin-based materials face challenges such as low yield, high solubility in alkaline and polar media, low glass transition temperature, and instability at high temperatures, limiting their application in material sciences.

Innovation Solution

A method involving the production of cross-linked lignin particles through a process that includes adjusting the pH, adding a cross-linking agent, and hydrothermal treatment of a black liquor solution to form stabilized lignin particles with high specific surface area, thereby enhancing their stability and suitability for material applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If hydrothermal carbonization is used to produce particulate carbon material from lignin, then specific surface area is improved, but yield deteriorates

Engineering Contradiction:
Improvespecific surface areaVSAvoidyield
Core Design Contradiction:
Area of stationary objectVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by precisely controlling pH value (adjusting to alkaline range above 7), ionic strength, and temperature during hydrothermal carbonization to achieve high specific surface area while maintaining acceptable yield. The method systematically varies these parameters to optimize the balance between surface area development and material recovery.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If pH value and ionic strength are adjusted to achieve high specific surface area, then manufacturing precision is improved, but device complexity deteriorates

Engineering Contradiction:
Improvespecific surface area controlVSAvoidprocess parameter adjustment complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent systematically adjusts pH value to alkaline range (above 7) and controls ionic strength as key parameters to achieve high specific surface area. These parameter changes are implemented through controlled addition of bases or removal of ions during hydrothermal treatment, providing precise control over particle morphology and surface area.

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

The method achieves high yield and produces cross-linked lignin particles with improved stability and specific surface area, suitable for use as fillers in rubber articles and tires, enhancing properties like elongation, dynamic stiffness, and electrical isolation.

Implementation Method 1

producing a liquid that contains lignin and at least one cross-linking agent... hydrothermal treatment of the liquid produced in step b) that contains lignin and at least one cross-linking agent... with formation of cross-linked lignin particles

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Implementation Method 2

hydrothermal treatment of the liquid produced in step b) that contains lignin and at least one cross-linking agent... at a temperature in the range from 150° C. to 270° C.

Methodology Applied
Scientific EffectHydrothermal treatment: Heating

Data Source

PatentUS12441849B2Method for producing a crosslinked lignin with a highly specified surface area, crosslinked lignin, and technical rubber articles or tires comprising crosslinked lignin
Publication Date: 2025.10.14 SUNCOAL INDS GMBH

AI summary

The invention relates to a method for producing a crosslinked lignin in particle form using a hydrothermal treatment of a liquid, which is made of black liquor, contains lignin and a crosslinker or a precursor thereof, and has an electrical activity ranging from more than 15 mS/cm, preferably more than 25 mS/cm, to 400 mS/cm, and to the crosslinked lignin produced using the aforementioned method. The invention additionally relates to crosslinked lignin particles which have a glass transition temperature Tg of at least 160° C. or no glass transition temperature and an STSA surface area of at least 10 m2/g and to rubber articles, in particular technical rubber articles or tires, which comprise crosslinked lignin particles as a filler.