Treated Titanium Dioxide Particles Resolving Photoactivity and Discoloration
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Solution Overview
Problem
There is a need for a process to improve the properties of titanium dioxide pigments, specifically reducing photoactivity and enhancing anti-microbial properties, for use in coatings, plastics, and laminates, which existing methods do not adequately address.
Innovation Solution
A process involving a silicon compound treatment followed by co-precipitated zinc oxide and alumina treatment is applied to titanium dioxide particles, resulting in reduced photoactivity, lower acid solubility, and improved anti-microbial properties, achieved through an aqueous suspension deposition and subsequent drying and micronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If titanium dioxide particles are used as pigment, then high photoactivity and white strength are achieved, but photochemical discoloration and mildew growth occur
Solution Approach 1:
The patent applies composite materials by combining titanium dioxide core particles with multiple treatment layers including silicon compounds, zinc oxide, and alumina. This composite structure allows the TiO2 to maintain its high photoactivity and white strength while the outer treatment layers provide protective functions against photochemical discoloration and mildew growth, resolving the contradiction between high photoactivity and resistance to harmful effects.
Solution Approach 2:
The patent applies local quality by providing different functional properties to different parts of the particle structure. The inner core maintains high photoactivity for white strength, while the outer treatment layers have localized functions including reduced photoactivity, anti-microbial properties, and protection against discoloration. This spatial differentiation of properties allows simultaneous achievement of high photoactivity and resistance to harmful factors.
2Reliability
If multiple substances are added to improve pigmentary properties, then durability and dispersability are improved, but process complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the treatment process into distinct sequential steps: first treating with silicon compounds, then with zinc oxide and alumina. Each step addresses specific properties (durability, dispersability, anti-microbial), allowing systematic improvement of multiple properties through modular process segments rather than a single complex operation.
Solution Approach 2:
The patent applies preliminary action by performing the silicon compound treatment first as a preparatory step before applying the zinc oxide and alumina treatment. This sequential preliminary actions approach allows each treatment to optimize specific properties building upon the previous step, improving overall reliability while managing process complexity through structured sequencing.
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 treated titanium dioxide particles exhibit improved durability, reduced acid solubility, and enhanced anti-microbial properties, making them suitable for high-gloss coatings and applications requiring resistance to mildew growth and photochemical discoloration.
Implementation Method 1
depositing a first treatment of a silicon compound, such as silica, on the inorganic particles
Implementation Method 2
depositing a second treatment over the first treatment, said second treatment comprising co-precipitated zinc oxide and alumina
Implementation Method 3
recovering the solids, washing free from water soluble species and drying
Data Source
AI summary
The disclosure provides a treated inorganic particle, in particular a titanium dioxide particle, having reduced photoactivity, lower acid solubility and improved anti-microbial properties comprising: an inorganic core particle, in particular a titanium dioxide particle; a first treatment of silica, wherein the silica is added in a single step; and a second treatment comprising co-precipitated zinc oxide and alumina. These particles have reduced photoactivity, lower acid solubility and improved anti-microbial properties.