Anionic Copolymer Dispersants for Stable Pigment Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current dispersants, such as nonionic novolak dispersants, contain alkylphenols that are environmentally harmful and difficult to replace with equivalent alternatives that can achieve high concentration pigment dispersions with stable color strength and broad compatibility in various media without foaming or shear instability.
Innovation Solution
Aqueous pigment preparations using specific anionic copolymers composed of polyethylene/polypropylene glycol mono(meth)acrylic esters as dispersants, which are synthesized to mimic the performance of nonionic novolak systems, providing high concentration, stable, and shear-resistant dispersions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nonionic novolak dispersants are used, then pigment dispersion performance is achieved, but environmental harm is caused due to alkylphenol residues
Solution Approach 1:
The patent changes the chemical structure parameters of the dispersant by replacing nonionic novolak with anionic copolymers containing carboxylate and sulfonate groups. This structural parameter change maintains dispersion performance while eliminating harmful alkylphenol residues, thus resolving the contradiction between reliability and environmental harm.
Solution Approach 2:
The patent employs readily available anionic polymer dispersants that can be easily synthesized or obtained, replacing the specialized novolak system. These alternative dispersants achieve comparable performance without the environmental persistence issues of alkylphenol ethoxylates.
2Object-affected harmful factors
If dispersants are replaced to eliminate alkylphenols, then environmental friendliness improves, but dispersion performance deteriorates
Solution Approach 1:
The patent adjusts the molecular parameters of the dispersant by selecting anionic copolymers with specific characteristics: molecular weights of 10³-10⁹ g/mol, containing polyethylene/polypropylene glycol chains with carboxylate and sulfonate groups. These parameter adjustments ensure environmental friendliness while maintaining high dispersion performance for organic pigments.
3Quantity of substance
If high concentration pigment dispersions are achieved, then color strength improves, but viscosity increases
Solution Approach 1:
The patent utilizes the specific parameter range of anionic copolymer dispersants (molecular weights 10³-10⁹ g/mol with specific monomer ratios) to achieve optimal steric and electrostatic stabilization. This allows formulation of high concentration pigment dispersions (40-80 wt%) while controlling viscosity through the balanced polymer architecture that prevents excessive thickening.
4Manufacturing precision
If pigment wetting is improved, then dispersion quality improves, but foaming increases
Solution Approach 1:
The patent employs dispersants with localized functional groups (carboxylate and sulfonate) positioned on polyethylene/polypropylene glycol chains. This local quality distribution provides effective pigment surface wetting and stabilization without generating excessive foam, as the amphiphilic structure concentrates surfactant activity at the pigment interface rather than at the air-liquid interface.
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 anionic copolymers achieve stable and reproducible color strength and hue, prevent foaming, and ensure broad compatibility in various application media, overcoming the limitations of traditional dispersants while being environmentally friendly.
Implementation Method 1
specific anionic copolymers, prepared by means of macromonomers composed of polyethylene/polypropylene glycol mono(meth)acrylic esters, achieve the stated object and equal nonionic novolak systems in their performance as dispersants
Implementation Method 2
aqueous pigment preparations comprising (A) at least one organic and/or inorganic pigment, (B) a dispersant of formula (I) or (II)... Q represents SO3, CH2COO, PO3M
Data Source
AI summary
The invention relates to aqueous pigment preparations containing (A) at least one organic and/or inorganic pigment, (B) a dispersant of formula (I) or (II), or mixtures of the dispersants of formula (I) and (II), (C) optionally wetting agents, (D) optionally other surfactants and/or dispersants, (E) optionally one or more organic solvents or one or more hydrotropic substances, (F) optionally other additives used conventionally for the production of aqueous pigment dispersions and (G) water.