Core-Shell Titanium Oxide Dispersion for Coating Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coating compositions face challenges in achieving high concentrations of titanium oxide without adverse effects on film physical properties, such as cissing and whitening, and require cumbersome adjustments and trial-and-error processes, while also suffering from degradation of film properties due to the use of dispersants in organic solvent dispersions.
Innovation Solution
A method for preparing an organic solvent dispersion of core/shell type tetragonal titanium oxide solid-solution particles with a core of tetragonal titanium oxide and a shell of silicon oxide, where the titanium oxide core has tin and manganese incorporated in solid solution, and a silicon compound or its hydrolytic condensate is added to form a stable dispersion that can be blended in coating compositions without degrading film properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If water dispersion of titanium oxide is used to achieve high concentration blending, then the coating composition can contain high levels of titanium oxide, but cissing and whitening problems arise in the coating
Solution Approach 1:
The patent changes the dispersion medium from water to organic solvent, which fundamentally alters the interaction between the dispersion medium and the coating composition. This parameter change allows high concentration blending of titanium oxide particles without causing cissing and whitening, as the organic solvent is compatible with the coating resin system.
Solution Approach 2:
The patent creates a replica of the water dispersion structure (core-shell particles with silica coating) but transfers it to an organic solvent medium. The core-shell structure is maintained while the dispersion medium is replaced, achieving the benefits of stable dispersion without the harmful effects of water in the final coating.
2Stability of the object's composition
If dispersant is added to achieve uniform dispersion of particles in organic solvent, then the particles disperse uniformly, but the hardness and adhesion of the coating composition are reduced
Solution Approach 1:
The patent extracts and eliminates the dispersant component from the system by pre-coating the titanium oxide particles with silica shell. This surface treatment provides inherent dispersion stability without requiring additional dispersant chemicals, thereby preserving the hardness and adhesion properties of the coating.
Solution Approach 2:
The silica shell is applied to the titanium oxide particles in advance, before incorporation into the coating composition. This preliminary surface treatment creates a stable surface that prevents aggregation and ensures uniform dispersion without needing dispersants during the coating formulation or application.
3Quantity of substance
If cumbersome steps are taken to achieve high concentration of titanium oxide in water dispersion, then the coating composition can contain high levels of titanium oxide, but extraordinary trial-and-error procedure is needed to find optimum composition
Solution Approach 1:
The patent uses a proven core-shell particle structure from water dispersion technology and replicates it in an organic solvent medium. This approach leverages existing knowledge of stable particle structures while avoiding the formulation complexities associated with water-based systems, reducing the need for trial-and-error optimization.
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 dispersion provides improved weather resistance and maintains film physical properties like mar resistance, transparency, and adhesion without the need for extensive trial-and-error, and can be used to create coatings with superior weather resistance compared to water-based dispersions.
Implementation Method 1
a silicon compound or its hydrolytic condensate is added to form a stable dispersion
Implementation Method 2
An organic solvent dispersion of titanium oxide solid-solution particles may be used as a UV absorber
Implementation Method 3
refractive index-providing agent in coating compositions
Data Source
Figure 1~2
Figure 3
AI summary
Core/shell type tetragonal titanium oxide solid-solution particles each consisting of a core of tetragonal titanium oxide having tin and manganese incorporated in solid solution and a shell of silicon oxide are dispersed in an organic solvent. The core/shell type particles have a diameter D50 of 5-50 nm. The amount of tin incorporated in solid solution is to provide a molar ratio Ti/Sn of 10-1,000, and the amount of manganese incorporated in solid solution is to provide a molar ratio Ti/Mn of 10-1,000.