Polyamidoamine Dispersants for PEI-Like Pigment Stabilization
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Solution Overview
Problem
Existing dispersants face challenges in achieving high performance without using highly toxic ethylene imine raw materials and in replicating the properties of polyethyleneimine (PEI)-based dispersants, while avoiding the complexities and costs associated with PEI synthesis and other alternatives like PAMAM dendrimers and ester-modified hyperbranched polyamidoamines fail to deliver satisfactory results.
Innovation Solution
A pigment dispersant is produced by reacting amine-rich moieties with a polymer containing amine-reactive groups, formed through repetitive self-reaction or cross-reaction of specific substances, achieving an amine density of 600-1,000 mg KOH/g, using linkers like acrylate or maleate/fumarate esters, and optionally further modified with substances like anhydrides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PEI is used as dispersant, then high amine density and strong pigment anchoring are achieved, but toxic raw materials and complex synthesis are required
Solution Approach 1:
The patent creates a simplified copy of PEI's essential functionality using polyamidoamine dendrimers with controlled amine density (500-1500 mg KOH/g) and specific amine types (primary, secondary, tertiary). Instead of replicating PEI's complex synthesis from toxic ethylene imine, the invention uses safe raw materials (diamines and acrylates) to produce dendrimers that copy the key dispersant properties: high amine density for pigment anchoring and hyperbranched structure for binder interaction.
2Object-affected harmful factors
If PEI structure is modified to reduce amine concentration, then toxicity is reduced, but active amine sites for binder interaction are consumed
Solution Approach 1:
The patent achieves non-toxic dispersants by changing the chemical composition parameters while maintaining functional performance. The polyamidoamine dendrimers are synthesized with controlled amine density (500-1500 mg KOH/g) and specific amine type distribution (primary, secondary, tertiary amines), replacing toxic PEI with safe raw materials. The dendrimer generation (G3-G7) and amine content are optimized to provide sufficient pigment anchoring and binder interaction without requiring toxic substances or excessive amine modification.
3Ease of manufacture
If PAMAM dendrimer structures are used, then synthesis is simplified, but amine density is too low for effective dispersant performance
Solution Approach 1:
The patent creates composite polyamidoamine dendrimer structures that combine the synthetic advantages of PAMAM with enhanced amine functionality. The dendrimers are built from diamine cores and acrylate linkers, maintaining the step-growth polymerization simplicity while incorporating additional amine-reactive groups and controlling the amine-to-linker ratio to achieve high amine density (500-1500 mg KOH/g). This composite approach merges manufacturing ease with dispersant effectiveness.
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 resulting dispersant achieves performance comparable to PEI-based dispersants, despite lower amine content, effectively stabilizing pigment interfaces and improving color strength in coating formulations.
Implementation Method 1
A pigment dispersant is produced by reacting amine-rich moieties with a polymer containing amine-reactive groups
Data Source
AI summary
A pigment dispersant can be obtained by reacting amine-rich moieties C with at least one polymer P having one or more amine reactive groups. The amine-rich moieties C have an amine density of at least 600 mg KOH/g and are obtainable from repetitive self-reaction of at least one type of substance B and/or from cross-reaction of at least one B with at least one substance A. B is an adduct of at least one substance A and at least one linker D. The amine-reactive functionality in B and D are reacted with reactive amines in B and/or A; and if B has only one amine reactive group, then additional D and/or mixture of B and A is reacted to a previously formed C, where such an additional reaction of D and/or mixture of B and A to a formed C is repeated for 1 to 10 times.