Low-VOC Wetting Agent for Pigment Dispersion
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Solution Overview
Problem
There is a need for low-VOC wetting and dispersing agents that can effectively disperse both inorganic and organic pigments in aqueous systems, ensuring storage stability and rheological properties suitable for further processing in paint systems, as existing agents are not universally applicable and often contain unacceptable zinc ions or other environmental concerns.
Innovation Solution
A mixture comprising 10-80% of a salted copolymer from ethylenically unsaturated phenyl group-containing monomers and α,β-unsaturated monocarboxylic or dicarboxylic acids, 1-30% of a water-soluble linear polyether, 5-80% of an esterification product from aliphatic dicarboxylic acid and water-soluble polyether, and 3-80% of a star polymer obtained by esterifying an aliphatic carboxylic acid with water-soluble polyether, which collectively function as a low-VOC wetting and dispersing agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wetting and dispersing agents are used, then pigment dispersion is achieved, but storage stability and rheological properties are insufficient
Solution Approach 1:
The invention uses a composite wetting and dispersing agent comprising multiple components: a salted copolymer (5-50% by weight) providing anionic charge for pigment interaction, and a nonionic polyether-containing wetting agent (50-95% by weight) providing steric stabilization and surface activity. This composite structure enables simultaneous achievement of storage stability and universal applicability across different pigment types including inorganic and organic pigments.
Solution Approach 2:
The wetting and dispersing agent is designed with dual functionality: the salted copolymer component provides electrostatic stabilization through carboxylate groups, while the nonionic polyether component provides steric stabilization and surfactant properties. This multi-functional design allows the same agent to effectively disperse various pigment types (inorganic like titanium dioxide, organic like phthalocyanines) while ensuring storage stability and proper rheological properties in aqueous low-VOC systems.
2Adaptability or versatility
If zinc-containing wetting and dispersing agents are used, then dispersing performance is improved, but environmental acceptability deteriorates
Solution Approach 1:
The invention extracts and removes zinc ions and other environmentally harmful metal components from the wetting and dispersing agent formulation. The dispersing performance previously attributed to zinc coordination is replaced by a combination of electrostatic stabilization from salted copolymer carboxylate groups and steric stabilization from nonionic polyether chains, eliminating toxic metal content while maintaining effective pigment dispersion.
Solution Approach 2:
The invention replaces persistent zinc-based dispersing agents with biodegradable polyether-containing surfactants and copolymers. These organic-based alternatives provide effective dispersing performance through non-toxic mechanisms (electrostatic and steric stabilization) and are environmentally acceptable, aligning with eco-friendly formulation requirements for low-VOC paint systems.
3Ease of operation
If high-VOC systems are used, then pigment dispersion and processing ease are improved, but VOC content exceeds environmental limits
Solution Approach 1:
The invention changes the formulation parameters by using aqueous-based low-VOC systems instead of organic solvent-heavy formulations. The wetting and dispersing agent is specifically designed to function effectively in aqueous media, with the salted copolymer providing water solubility through ionized carboxylate groups and the polyether component providing hydrophilic-lipophilic balance. This parameter change enables processing ease comparable to high-VOC systems while maintaining VOC content below environmental limits.
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 described mixture provides excellent storage stability and rheological properties for aqueous pigment concentrates, making them suitable for further processing in paint systems, while being environmentally friendly and applicable to a wide range of pigments, thus addressing the limitations of existing agents.
Implementation Method 1
wetting and dispersing agents that are suitable for dispersing a wide variety of pigments
Implementation Method 2
combination of copolymers containing carboxyl groups... and non-ionic or anionic, polyether-containing wetting agents
Implementation Method 3
ensure the necessary rheological properties both in pigment pastes and also ensure in appropriate paint systems
Data Source
AI summary
The present invention relates to low-VOC mixtures of at least partially salted copolymers of at least one ethylenically unsaturated, phenyl group-containing monomer and at least one a,ß-unsaturated monocarboxylic acid and/or at least one a,ß-unsaturated dicarboxylic acid, of at least one water-soluble polyether, esterification products of at least one water-soluble polyether and an aliphatic dicarboxylic acid and a star polymer, obtainable by the esterification of a carboxylic acid comprising at least three carboxyl groups with at least one water-soluble polyether. The invention further relates to the use of a low-VOC mixture according to the invention as a wetting and dispersing agent, preferably for the production of low-VOC pigment pastes or low-VOC paint systems.