Titanium Dioxide Coating Attachment via Steam Micronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for treating titanium dioxide particulate solids with coating materials do not effectively achieve high attachment levels of the coating agent, leading to suboptimal performance in polymer compositions, particularly in terms of melt flow index, dispersability, and volatile evolution.
Innovation Solution
A method involving particulate titanium dioxide coated with aluminium oxide or having aluminium oxide in excess within its crystal structure, treated with an alkylphosphonic acid or ester, and steam micronized at a vapour exit temperature of 150°C or higher to enhance coating agent attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional coating methods are used to treat titanium dioxide particles with organophosphorus compounds, then the coating process can be completed, but the attachment level of the coating agent remains insufficient
Solution Approach 1:
The patent applies parameter changes by controlling the steam micronization temperature (150°C or higher) and the amount of aluminium oxide (0.01-3% by weight) to optimize the attachment of alkylphosphonic acid coating agent to titanium dioxide particles, transforming the coating process from insufficient to effective
Solution Approach 2:
The patent implements preliminary action by pre-coating titanium dioxide particles with aluminium oxide before applying the organophosphorus coating agent. This preparatory step creates optimal surface conditions that enhance subsequent coating agent attachment during steam micronization
2Quantity of substance
If more coating material is added to increase attachment, then coating coverage improves, but process complexity and cost increase
Solution Approach 1:
The patent applies self-service by utilizing the steam micronization process itself to achieve both particle size reduction and coating agent attachment simultaneously. The steam environment and thermal energy inherent to the micronization process directly facilitate coating attachment, eliminating the need for separate coating equipment or complex multi-step processes
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
This method achieves higher levels of coating agent attachment, improving properties such as melt flow index, dispersability, and reducing volatile evolution when incorporated into polymer compositions.
Implementation Method 1
treating the particulate titanium dioxide with a coating agent that is an alkylphosphonic acid or ester thereof... so as to obtain a micronized particulate titanium dioxide that is provided with coating agent at its outer surface
Implementation Method 2
steam micronizing the particulate titanium dioxide, wherein the vapour exit temperature from the steam micronizer is 150°C or higher
Data Source
AI summary
The invention provides a method of treating particulate titanium dioxide. The method comprises: i) providing particulate titanium dioxide, wherein the particulate titanium dioxide is coated with aluminium oxide, and/or includes within its crystal structure aluminium oxide in molar excess of the amount required to compensate any Nb205 in said crystal structure; and then ii) treating the particulate titanium dioxide with a coating agent that is an alkylphosphonic acid or ester thereof, wherein the alkylphosphonic acid has a C6-C22 alkyl group, and steam micronizing the particulate titanium dioxide, wherein the vapour exit temperature from the steam micronizer is 150°C or higher, so as to obtain a micronized particulate titanium dioxide that is provided with coating agent at its outer surface. The treated particulate titanium dioxide as obtained by the method can be incorporated into a polymer composition so as to increase its melt flow index, improve its dispersability, increase its hydrophobicity and/or increase its bulk density.