Solvent-Free Mefenpyr-Diethyl Formulations via Phase Transition
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Solution Overview
Problem
Current formulations for low-melting herbicide safeners, such as mefenpyr-diethyl, require organic solvents for dissolution, leading to unstable and less concentrated aqueous emulsions or suspoemulsions, and result in quality issues like agglomeration and contamination in water-dispersible granules, which are environmentally and economically undesirable.
Innovation Solution
A process involving melting the herbicide active ingredient between 50°C and 80°C, mixing it with water containing ionic and/or non-ionic dispersants, cooling below the melting point, and then grinding with carrier materials to produce solvent-free, highly concentrated aqueous suspension concentrates and water-dispersible granules that are stable and non-agglomerative.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If organic solvents are used to dissolve low-melting herbicide safeners, then the active ingredient can be formulated, but the formulations become unstable emulsions or suspensions with lower concentrations
Solution Approach 1:
The patent changes the physical state parameter of the active ingredient from solid to liquid by heating above melting point (50-80°C), enabling direct mixing with water to form stable suspensions without organic solvents. This parameter change resolves the contradiction by allowing high concentration formulation while maintaining stability through controlled phase transition
Solution Approach 2:
The patent utilizes melting phase transition of the herbicide safener (mefenpyr-diethyl or cloquintocet-mexyl) to convert solid particles into liquid state for homogeneous mixing with water. The subsequent cooling induces crystallization to form stable suspension. This phase transition approach eliminates organic solvents while achieving both high concentration and formulation stability
2Object-generated harmful factors
If low-melting herbicide safeners are directly added to water, then aqueous formulations are produced, but the substances cannot be dissolved due to low melting range and amorphous structure
Solution Approach 1:
The patent applies temperature parameter change to melt the amorphous low-melting herbicide safener, transforming it from a non-dissolvable solid state to a liquid state that can be readily mixed with water. This resolves the formulability issue while maintaining the environmental benefit of solvent-free aqueous formulation
Solution Approach 2:
The patent introduces water as an intermediary medium to receive the melted active ingredient. The dispersants act as intermediaries to stabilize the suspension of crystallized particles in water, enabling direct aqueous formulation without organic solvents while solving the dissolution problem
3Manufacturing precision
If purification through crystallization is performed, then the active ingredient can be purified, but the process becomes complex and expensive, and particles clump together during milling
Solution Approach 1:
The patent performs preliminary melting of the crude herbicide safener before purification. This preliminary action softens the material, enabling effective purification during cooling and crystallization without requiring complex pre-treatment processes. The melted state facilitates impurity separation while preventing particle clumping that would occur with solid handling
Solution Approach 2:
The patent utilizes the phase transition from liquid to solid during cooling to achieve purification. As the melted active ingredient cools, pure crystals form while impurities remain in the melt or separate differently. This phase transition-based purification is simpler and more effective than traditional solid-state crystallization methods
4Productivity
If highly concentrated formulations are produced, then packaging and transport effort are reduced, but the active ingredient must be dissolved or formulated in organic solvents first
Solution Approach 1:
The patent applies temperature parameter change (heating to melting point) to enable direct concentration of the active ingredient in aqueous suspension without organic solvents. This allows production of highly concentrated formulations (up to 50% w/w) that are both environmentally friendly and logistically efficient, resolving the contradiction between productivity and environmental impact
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
This method produces stable, highly concentrated, solvent-free formulations that prevent agglomeration and contamination, enhancing the economic and ecological viability of herbicide application by eliminating the need for organic solvents and improving handling and storage efficiency.
Implementation Method 1
at least one agrochemical active ingredient a) with a melting point range between 50°C and 80°C is melted
Implementation Method 2
the mixture is cooled below the melting point of the active ingredient
Implementation Method 3
the mixture is cooled below the melting point of the active ingredient
Data Source
AI summary
The present invention relates to solvent-free aqueous suspension concentrates and solvent-free solid, water-dispersible formulations, containing one or more low-melting active substances and to processes for their preparation. The formulations according to the invention are suitable for use in the field of plant protection.