Latex Adducts for Quick-Setting Stability
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Solution Overview
Problem
The coating industry faces challenges in achieving both quick setting and stability in latex products, particularly due to the instability caused by the addition of fast-evaporating solvents like methanol, which can lead to coagulation of anionically-stabilized latex particles, especially when polyfunctional amines with high basicity are present.
Innovation Solution
A latex product composition comprising anionically-stabilized latex, a volatile base compound, and polymers or polymeric adducts with a backbone of amine and hydroxyl functional groups, formed from multifunctional amine compounds reacted with epoxy compounds, providing a balanced molecular weight and nitrogen content to maintain stability and facilitate quick setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If fast-evaporating solvents like methanol are added to latex products to achieve quick setting, then drying time is reduced, but stability of the latex product deteriorates due to coagulation of anionically-stabilized latex particles
Solution Approach 1:
The patent introduces a volatile base compound as an intermediary substance that mediates between the latex particles and the fast-evaporating solvent. The volatile base compound temporarily counteracts the coagulation effect of the solvent during storage, and then evaporates during application, allowing the solvent to achieve its quick-drying function without compromising stability
Solution Approach 2:
The patent changes the pH parameter of the latex product by adding a volatile base compound, which increases the pH to prevent protonation of the polyfunctional amine and thus prevents coagulation during storage. After application, the volatile base evaporates, allowing the pH to decrease and enabling the quick-setting function
2Productivity
If polyfunctional amines with high basicity are added to latex products to achieve quick setting, then setting speed is improved, but stability deteriorates due to increased tendency to coagulate anionically-stabilized latex particles
Solution Approach 1:
The volatile base compound acts as a mediator that protects the polyfunctional amine from causing coagulation during storage by maintaining a high pH environment. During application, the volatile base evaporates, allowing the polyfunctional amine to exert its quick-setting effect without being constrained by stability requirements
Solution Approach 2:
The patent creates a dynamic system where the pH of the latex product changes over time: high pH during storage (due to volatile base) to maintain stability, and low pH after application (after volatile base evaporation) to enable quick setting. This temporal dynamic allows both stability and productivity to be optimized at different stages
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 composition exhibits enhanced storage stability and accelerated drying time, with the latex product becoming tack-free or dry-through at least 25% faster than similar compositions without polyamine additives, while maintaining stability even at lower pH values.
Implementation Method 1
a volatile amine is added to the latex product in order to increase the pH to a level that prevents the protonation of the polyfunctional amine
Implementation Method 2
When the latex product is applied on to a substrate, the volatile amine escapes or evaporates from the applied coating composition. The loss of the volatile amine results in a decrease in the pH of the applied latex coating composition. The decrease in pH triggers the coagulation of the latex particles
Implementation Method 3
protonated polyfunctional amines destabilize the anionically-stabilized latex particles present in the latex products after they are coated onto a substrate
Data Source
AI summary
A latex product composition that includes an anionicaily-stabilized latex; at least one volatile base compound; and one or more water soluble, polymers or polymeric adducts that have a backbone with a plurality of amine functional groups and hydroxyl functional groups. The polymers or polymeric adducts may be an addition product formed from at least one multifunctional amine compound reacted with one or more polyfunctional epoxy compounds, one or more monofunctional epoxy compounds, or a combination thereof. The polymers or polymeric adducts are formed by the addition reaction of the amine compound and the one or more epoxy compounds with 1.3 to 3.8 amine functional group per epoxy functional group. The addition product may be present in about 0.1 to 15.0 wt. % and the at least one volatile base compound is present in about 1.0 wt. % to 10.0 wt. % based on the weight of the particles present in the anionicaily-stabilized latex.