Urea Urethane Polymer Preparation Without Diisocyanate Distillation
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Solution Overview
Problem
Existing processes for preparing urea urethane polymers require a diisocyanate distillation step, leading to inefficiencies and instability in the final product due to unreacted diisocyanate, which limits their use in paint and coating formulations.
Innovation Solution
A process involving a molar ratio of monohydroxyl compound to toluene diisocyanate between 1:1 and 1.5:1, with reaction in the presence of a polar aprotic solvent and lithium salt, eliminates the need for diisocyanate distillation, resulting in a stable urea urethane polymer that imparts thixotropic properties to formulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If diisocyanate distillation step is used to prepare urea urethane polymer, then purity of the polymer is improved, but process complexity and production time increase
Solution Approach 1:
The invention removes the diisocyanate distillation step from the preparation process by using a molar ratio of monohydroxyl compound to diisocyanate between 1:1 and 1.5:1, ensuring complete reaction without excess diisocyanate that would require distillation removal
Solution Approach 2:
The invention performs preliminary action by carefully controlling the molar ratio of reactants before the reaction occurs, preventing the formation of unreacted diisocyanate in the first place, thereby eliminating the need for subsequent distillation to remove it
2Reliability
If diisocyanate distillation step is used to prepare urea urethane polymer, then stability of the polymer is improved, but production time increases
Solution Approach 1:
The invention extracts the diisocyanate distillation step from the process entirely by using stoichiometric control (molar ratio 1:1 to 1.5:1 of monohydroxyl compound to diisocyanate), achieving both time savings and stability through complete reaction
Solution Approach 2:
The invention changes the key parameter of molar ratio from traditional excess diisocyanate conditions to a controlled 1:1 to 1.5:1 ratio, which fundamentally alters the reaction outcome to eliminate unreacted diisocyanate and the need for distillation while maintaining product stability
3Manufacturing precision
If excess diisocyanate is used in the reaction, then completeness of reaction is improved, but product stability deteriorates due to unreacted diisocyanate
Solution Approach 1:
The invention optimizes the molar ratio parameter to between 1:1 and 1.5:1 (monohydroxyl compound to diisocyanate), which is sufficient for complete reaction while preventing excess diisocyanate from remaining in the final product, thus maintaining both completeness and stability
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 process produces a storage-stable urea urethane polymer that effectively imparts thixotropic effects to paint and coating formulations without the need for diisocyanate distillation, enhancing their thickening and flow properties.
Implementation Method 1
a monohydroxyl compound is reacted in the presence of diisocyanate to synthesize a monoisocyanate adduct
Implementation Method 2
the monoisocyanate adduct is reacted with diamine in the presence of a lithium salt and carrier solvent
Implementation Method 3
the formation of reversible hydrogen bonds. Once the urea-urethane additive is mixed into the coating, the hydrogen bonds form between the additives and the coating forms a gel
Implementation Method 4
Upon the addition of shear (mixing, shaking, etc.) the hydrogen bonds break up and the coating becomes flowable
Implementation Method 5
After the shear force is removed, the hydrogen bonds build up again and the coating forms a gel again
Implementation Method 6
the monoisocyanate adduct is reacted with diamine in the presence of a lithium salt and carrier solvent
Data Source
AI summary
The presently claimed invention relates to a process for preparing urea urethane polymer, liquid compositions comprising the urea urethane polymer and the use of the urea urethane polymer as a thickening and thixotropic agent for water based and solvent based paint and coating formulations, lacquer, varnish, paper coating, wood coating, adhesive, ink, cosmetic formulation, detergent formulation, textile and drilling muds plaster formulations, PVC plastisol and cement formulations.