Low Mass Polymer Grinding Aid for Mineral Suspension Stability

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Solution Overview

Problem

Existing grinding aid agents for mineral materials in the papermaking industry fail to effectively control the rheology and stability of mineral suspensions during grinding, leading to issues with viscosity drift and particle settling, which affects the quality and productivity of paper coating colors.

Innovation Solution

A polymer with a molecular mass of less than 8,000 g/mol and a polymolecularity index of less than 3 is synthesized through radical polymerization in water at temperatures above 50°C, using a specific combination of phosphorus compounds in oxidation states I and III, along with a radical-generating compound, to enhance the performance of grinding aid agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional grinding aid agents are used, then the rheology of mineral suspension can be controlled, but viscosity drift and particle settling occur, reducing suspension stability

Engineering Contradiction:
Improvesuspension stabilityVSAvoidviscosity control reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention changes the chemical parameters of the grinding aid agent by specifying a polymer with molecular mass between 1,000-8,000 g/mol and polymolecularity index between 1.2-3.0, obtained by radical polymerisation at temperatures above 50°C in the presence of phosphorus compounds. These parameter changes resolve the contradiction by providing a polymer structure that maintains stable viscosity and prevents particle settling, thereby improving suspension stability while maintaining reliable viscosity control throughout the grinding process.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If high concentration of mineral material is used in aqueous suspension, then productivity increases, but viscosity increases, making handling difficult

Engineering Contradiction:
Improvegrinding productivityVSAvoidviscosity resistance
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The invention changes the rheological parameters of the suspension by using a specifically designed polymer grinding aid with controlled molecular mass and polymolecularity index. This polymer optimizes the balance between solids content and viscosity, enabling high productivity through high mineral material concentration while maintaining manageable viscosity levels for easy handling and processing.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If grinding time is reduced to improve yield, then productivity increases, but particle size control and granulometry precision may deteriorate

Engineering Contradiction:
Improvegrinding yieldVSAvoidparticle size control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention applies preliminary action by pre-optimizing the polymer structure (molecular mass 1,000-8,000 g/mol, polymolecularity index 1.2-3.0) before the grinding process. This pre-configured polymer structure facilitates rapid particle size reduction and maintains excellent granulometry control, allowing the grinding process to achieve both high productivity and high precision simultaneously without requiring extended grinding times.

Inventive Principle:
Principle #10Preliminary action

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 polymer improves the stability and viscosity control of mineral suspensions, allowing for higher solids content and reduced water usage, thereby increasing productivity and maintaining suspension stability over time, while also serving as an effective detergent or scale-inhibiting agent.

Implementation Method 1

obtained by radical polymerisation in water and at a temperature greater than 50° C. of at least one anionic monomer comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group, in the presence of phosphorus in the oxidation I state, phosphorus in the oxidation III state, and a radical-generating compound

Methodology Applied
Scientific EffectRadical polymerisation: Photopolymerisation

Data Source

PatentUS12139562B2Copolymer and grinding of a mineral matter
Publication Date: 2024.11.12 COATEX SA

AI summary

A polymer may have a molecular mass of less than 8,000 g/mol and a polymolecularity index PI of less than 3, produced by free radical polymerization, in water, and at a temperature higher than 50° C., of at least one anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function, in the presence of phosphorus with a degree of oxidation I, phosphorus with a degree of oxidation III and a radical-generating compound. Such polymers may be produced and use for grinding mineral matter, as a detergent agent, or as an anti-scaling agent.