Polymeric Dye Synthesis Without Heavy Metals
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Solution Overview
Problem
Current inkjet printing dyes are often solvent-soluble and contain heavy metals, making them hazardous for human health and the environment, and are banned from sensitive markets due to migration concerns.
Innovation Solution
A method for synthesizing organic solvent-soluble polymeric dyes without heavy metals, involving the functionalization of dyes with polymerizable functions, copolymerization with other polymerizable monomers, and purification using specific solvents like acetonitrile and di-isopropyl ether.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional solvent-soluble dyes containing heavy metals are used, then good color performance and solubility are achieved, but human health safety and environmental compatibility deteriorate
Solution Approach 1:
The patent removes heavy metal cations (chromium, copper, cobalt, iron) from the dye composition entirely, extracting the harmful metallic component while retaining the organic chromophore structure. This is achieved by using only organic counterions such as alkali metal cations (sodium, potassium), alkaline earth metal cations (calcium, magnesium), or organic cations (tetraalkylammonium), thereby eliminating CMR (carcinogenic, mutagenic, reprotoxic) hazards while maintaining dye functionality
Solution Approach 2:
The patent changes the chemical composition parameters by replacing metallic cations with organic cations. Specifically, it uses alkali metal cations (Na+, K+), alkaline earth metal cations (Ca2+, Mg2+), or organic cations (tetraalkylammonium ions) instead of heavy metals. This parameter change transforms the dye from hazardous to safe for sensitive markets while preserving solubility and color performance
2Object-affected harmful factors
If polymeric dyes are used to prevent migration, then safety for sensitive markets is improved, but solubility in organic solvents deteriorates
Solution Approach 1:
The patent applies local quality by creating an amphiphilic polymer structure where hydrophilic segments (containing chromophores and polar groups) provide solubility in organic solvents, while hydrophobic segments (polymer backbone) provide high molecular weight for migration prevention. The polymer contains both polar groups (carboxyl, hydroxyl, amine) for solvent interaction and non-polar polymer chains for migration resistance
Solution Approach 2:
The patent creates a composite polymeric dye structure combining organic chromophores with polymerizable groups (acrylate, methacrylate, vinyl). This composite structure integrates the color-generating chromophore molecules with polymer chains, achieving both high molecular weight (for migration prevention) and organic solvent solubility (through ester groups and polar functionalities in the polymer structure)
3Productivity
If DMF and diethyl ether are used as solvents, then polymeric dye synthesis is achieved, but toxicity and explosion risk increase
Solution Approach 1:
The patent replaces hazardous solvents with safer alternatives that are less toxic and less flammable. Specifically, it substitutes DMF (carcinogenic) with water or alcohol-water mixtures, and replaces diethyl ether (highly flammable and explosive) with di-isopropyl ether or methyl tert-butyl ether which have lower flammability and explosion risks. These alternative solvents achieve comparable polymerization efficiency without the severe hazards
Solution Approach 2:
The patent converts the limitation of water/alcohol solvents (which were traditionally considered unsuitable for polymerization) into a benefit by demonstrating that they can effectively serve as polymerization media. The use of water or alcohol-water mixtures eliminates CMR chemical concerns while maintaining polymerization efficiency, turning a perceived disadvantage into an advantage for safety compliance
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 polymeric dyes are safe for sensitive markets, exhibit excellent stability, printability, solubility in organic solvents, and adhesion to various substrates, while avoiding the use of hazardous solvents and improving yield.
Implementation Method 1
copolymerizing at least one polymerizable monomer dye with polymerizable monomers
Implementation Method 2
the purification of the resulting polymeric dye is conducted in a solvent chosen from di-isopropyl ether, methyl tert-butyl ether, dimethyl carbonate, ethyl acetate, and water
Data Source
AI summary
The present invention relates to a method for synthetizing a polymeric dye by polymerization of polymerizable monomers bearing a polymerizable function, such as acrylate, methacrylate, acrylamide, or methacrylamide, and a chromophore function, wherein the polymerization is conducted in a solvent chosen from acetonitrile or a mixture of methyl ethyl ketone and ethanol and the purification of the resulting polymeric dye is conducted with a solvent chosen from di-isopropyl ether, methyl tert-butyl ether, dimethyl carbonate, ethyl acetate, and water. The invention also relates to the resulting polymeric dye and to ink compositions comprising it.