Monoisocyanate-Based Urethane Rheology Modifier for Paint Viscosity
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Solution Overview
Problem
Existing rheology-modifying compounds, such as HEUR-type urethanes, fail to achieve a satisfactory balance between Stormer viscosity at low or medium shear rates and ICI viscosity at high or very high shear rates, leading to inadequate viscosity ratios and unsatisfactory paint application properties.
Innovation Solution
A urethane compound is prepared by reacting monoisocyanate compounds with alkylene glycol in the presence of polyisocyanate compounds, without using diisocyanate compounds, utilizing a multi-step process involving specific catalysts to control the reactivity of isocyanate functions, resulting in a hydrophilic compound suitable for aqueous formulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If HEUR-type compounds are used as rheology modifying agents, then paint formulation can be stabilized, but the compromise between Stormer viscosity and ICI viscosity is not satisfactory
Solution Approach 1:
The patent changes the chemical structure parameters of the urethane compound by controlling the ratio of monofunctional to polyfunctional isocyanate compounds and adjusting the molecular weight distribution, resulting in improved rheology modifying properties and better viscosity ratio control between Stormer and ICI measurements
Solution Approach 2:
The patent uses a composite approach by combining monofunctional isocyanate compounds with polyfunctional isocyanate compounds in specific ratios, creating a urethane compound that integrates the advantages of both components to achieve satisfactory rheology modification and viscosity control
2Productivity
If high viscosity is sought at low or medium shear rates, then paint pick-up and stabilization are improved, but splatter and droplet formation increase during application
Solution Approach 1:
The patent creates a dynamic viscosity profile by designing a urethane compound that provides high viscosity at low shear rates for good paint pick-up and stabilization, while maintaining lower viscosity at high shear rates during application to prevent splatter and droplet formation, achieving adaptability across different operational conditions
3Manufacturing precision
If high viscosity is sought at high shear rates, then filling power and uniform film formation are improved, but paint application becomes difficult
Solution Approach 1:
The patent designs a shear-thinning rheological profile where the urethane compound provides high viscosity at rest for film uniformity and filling power, but reduces viscosity under application shear to facilitate easy paint application, balancing formulation performance with operational ease
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 urethane compound effectively controls viscosity across various shear rates, enhancing paint application by improving paint pick-up, reducing splatter, ensuring uniform film formation, and maintaining a high ICI viscosity to Stormer viscosity ratio, thus improving the appearance and stability of paint coatings.
Implementation Method 1
a monoisocyanate compound, in particular a monoisocyanate compound resulting from the separate condensation of an asymmetric diisocyanate compound with a reactive compound, is reacted with an alkylene glycol compound in the presence of a polyisocyanate compound
Implementation Method 2
the condensation of compounds (A), (B) and (C) is carried out in the presence of a catalyst
Data Source
AI summary
The invention relates to a rheology-modifying urethane compound. The compound comprising urethane functions of the invention can be prepared according to a process in several steps which use different compounds comprising isocyanate functions. For the preparation of the urethane compound according to the invention, a monoisocyanate compound, in particular a monoisocyanate compound resulting from the separate condensation of an asymmetric diisocyanate compound with a reactive compound, is reacted with an alkylene glycol compound in the presence of a polyisocyanate compound. The invention also provides coating compositions comprising mineral particles and a urethane compound according to the invention.