Raspberry-like Titanium Oxide Composite Particles for Stable Aqueous Dispersion
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Solution Overview
Problem
Existing methods for producing aqueous dispersions of titanium oxide particles face challenges in achieving both high whiteness and stability, particularly when printing on non-white recording media, as they often result in pigment precipitation and reduced redispersibility.
Innovation Solution
A method involving the production of raspberry-like titanium oxide composite particles by adding a polymerizable monomer and a polymerization initiator to an aqueous titanium oxide dispersion, where the polymerizable monomer is added at a mass ratio of 1/5 or more relative to the titanium oxide particles, and contains a polymerizable monomer A with low water solubility, resulting in resin particles that cover the titanium oxide particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional aqueous titanium oxide dispersion is used, then the dispersion can be maintained simple, but pigment precipitation occurs and redispersibility is reduced
Solution Approach 1:
The patent creates composite particles by coating titanium oxide particles with polymer resins formed through polymerization of monomers in the aqueous dispersion. This composite structure (titanium oxide core with polymer coating) prevents pigment precipitation while maintaining redispersibility, resolving the contradiction between dispersion stability and redispersibility.
Solution Approach 2:
The patent changes the physical-chemical parameters of the dispersion by introducing polymerizable monomers and polymerization initiators, transforming the simple aqueous titanium oxide dispersion into a complex system where polymer resins are formed in situ. This parameter change enables the formation of stable composite particles that prevent precipitation while maintaining redispersibility.
2Illumination intensity
If titanium oxide particles are used for white ink, then high whiteness can be achieved, but pigment precipitation occurs
Solution Approach 1:
The patent forms composite particles where titanium oxide particles are coated with polymer resins. This composite structure maintains the high whiteness of titanium oxide while the polymer coating prevents aggregation and precipitation, thereby improving dispersion stability.
Solution Approach 2:
The polymer resin acts as an intermediary substance between the titanium oxide particles and the aqueous dispersion medium. This intermediary coating on the titanium oxide particle surfaces prevents direct contact and aggregation, thereby preventing precipitation while preserving the high whiteness property.
3Device complexity
If polymerizable monomer is added at low mass ratio, then the dispersion remains simple, but whiteness and stability are insufficient
Solution Approach 1:
The patent specifies adding polymerizable monomer at a mass ratio of 1/5 or more relative to titanium oxide particles. This parameter change ensures sufficient polymer resin formation to cover titanium oxide particle surfaces, achieving both high whiteness and stability, while the controlled addition rate manages dispersion complexity.
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 method achieves enhanced whiteness and stability of the aqueous dispersion, suppressing pigment precipitation and improving redispersibility, while maintaining the high reflectance of visible light due to the increased surface area of the raspberry-like particles.
Implementation Method 1
adding a polymerizable monomer and a polymerization initiator to the aqueous titanium oxide dispersion to polymerize the polymerizable monomer
Data Source
AI summary
A method for producing an aqueous dispersion is disclosed, the method including: obtaining an aqueous titanium oxide dispersion containing titanium oxide particles, a dispersant, and water; and obtaining titanium oxide composite particles by adding a polymerizable monomer and a polymerization initiator to the aqueous titanium oxide dispersion to polymerize the polymerizable monomer, in which the obtaining of the titanium oxide composite particles includes adding the polymerizable monomer at a mass ratio of 1/5 or more relative to the total amount of the titanium oxide particle at one time, and the polymerizable monomer contains a polymerizable monomer A of which solubility in water is 0.5 g/100 ml or less at 23° C. An aqueous dispersion and an aqueous ink are also disclosed.