Amphoteric Polymer Particles for Opacifying Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Opacifying coatings struggle to achieve high opacity and whiteness while minimizing pigment usage, as increased pigment levels lead to particle crowding, reducing light scattering efficiency and hiding power.
Innovation Solution
A stable aqueous dispersion of multiphase amphoteric polymer particles with specific structural units and weight ratios, which adsorb onto inorganic pigment particles, optimizing particle spacing and light scattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If higher levels of opacifying pigment are used to achieve desired hiding and whiteness, then hiding power is improved, but light scattering efficiency is reduced due to particle crowding
Solution Approach 1:
Polymer particles containing select chemical groups (carboxylic acid, sulfur acid, amine, or quaternary ammonium salt groups) are introduced as intermediaries that promote adsorption to the opacifying pigment particles. This mediator approach allows better pigment distribution and spacing without requiring excessive pigment levels, thus maintaining light scattering efficiency while achieving adequate hiding power.
Solution Approach 2:
The invention changes the chemical parameter of the polymer particles by incorporating specific functional groups that can interact with pigment particles. This parameter change enables controlled adsorption and spacing of pigment particles, optimizing the balance between hiding power and light scattering efficiency.
2Productivity
If opacifying coatings are formulated to maximize hiding for a defined level of pigment, then pigment utilization is minimized, but complete covering requires sufficient pigment levels to overcome particle crowding effects
Solution Approach 1:
The polymer particles act as intermediaries that enhance the effectiveness of each pigment particle by optimizing its spatial distribution. This allows the coating to achieve complete covering with reduced pigment levels, thereby improving pigment utilization efficiency while avoiding the crowding effects that would otherwise require excessive pigment amounts.
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 solution enhances hiding efficiency, whiteness, and gloss in dried coatings by minimizing particle crowding and optimizing pigment distribution, achieving improved opacity with reduced pigment usage.
Implementation Method 1
polymer particles containing select chemical groups that promote adsorption to the opacifying pigment particle
Implementation Method 2
the light scattering capability of the opacifying pigment is maximized
Data Source
AI summary
The present invention relates to a stable aqueous dispersion of multiphase amphoteric polymer particles comprising a crosslinked polymer phase comprising structural units of a phosphorus acid monomer, a carboxylic acid monomer, a multiethylenically unsaturated monomer, and an ethylenically unsaturated nonionic monomer; and a second polymer phase comprising a carboxylic acid monomer and an ethylenically unsaturated nonionic monomer. The present invention also relates to composites of the particles and pigment particles such as TiO2. The composition is useful for preparing dried coatings with improved hiding.