Spherical Calcium Titanate Powder for Toner Fluidity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a lack of calcium titanate fine particles with an average particle size of 100 nm or less suitable as charge adjusting agents, fluidizing agents, or fusion-preventing agents for electrophotographic toners, and existing methods produce coarse or irregularly shaped particles that do not effectively replace titanium dioxide.
Innovation Solution
A high-pressure liquid phase reaction method is used to produce substantially spherical calcium titanate powder by adding sugar to a mixture of a titanium compound, a water-soluble calcium compound, and an alkali, followed by a calcium removal treatment to achieve fine particle sizes and improve fluidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If calcium titanate is produced by conventional methods (wet synthesis or autoclave heating), then calcium titanate particles can be obtained, but the particle size is coarse (1 μm to 3 μm) or irregularly shaped, which is insufficient for effective fluidizing agent performance
Solution Approach 1:
The invention changes the reaction parameters by conducting the synthesis in a high-pressure liquid phase environment (autoclave heating at elevated temperature and pressure), which enables precise control of particle size to 100 nm or less while maintaining perovskite structure formation. This parameter change resolves the contradiction between achieving fine particle size and managing production complexity.
Solution Approach 2:
The invention uses a composite approach by combining calcium compound and titanium compound in specific molar ratios within a controlled reaction system, producing calcium titanate with precise stoichiometry and controlled morphology. This composite material strategy enables simultaneous control of particle size, shape, and crystalline structure.
2Reliability
If calcium titanate particles are produced with cubic or rectangular parallelepiped shapes having pointed angles, then the perovskite structure can be formed, but the fluidizing performance is inferior to spherical titanium dioxide particles
Solution Approach 1:
The invention applies spheroidality by controlling the crystallization process to produce substantially spherical calcium titanate particles instead of cubic or rectangular shapes. The high-pressure liquid phase reaction conditions promote isotropic growth, resulting in spherical morphology with smooth surfaces that eliminates pointed angles, thereby achieving fluidizing performance comparable to spherical titanium dioxide.
3Reliability
If titanium dioxide is used as external additive for toner, then charge adjustment and fluidizing properties are achieved, but carcinogenic risk increases according to IARC classification
Solution Approach 1:
The invention replaces titanium dioxide with calcium titanate, which has similar functional properties for charge adjustment and fluidizing but without the carcinogenic risk. This material substitution principle eliminates the harmful factor while maintaining the required toner performance characteristics.
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 resulting calcium titanate powder with a perovskite-type crystal structure and spherical shape enhances toner fluidity and prevents particle fusion, making it an effective alternative to titanium dioxide in electrophotographic toners.
Implementation Method 1
a mixed solution containing a compound obtained by deflocculating a hydrolysate of a titanium compound
Implementation Method 2
the obtained calcium titanate powder is composed of particles containing calcium titanate having a perovskite-type crystal structure
Implementation Method 3
heating the mixed solution to 100°C or more and 270°C or less
Data Source
Figure 1~2
AI summary
A powder which is composed of particles that are mainly composed of calcium titanate having a perovskite crystal structure, and primary particles of which have a generally spherical shape and an average particle diameter within the range of from 20 nm to 100 nm (inclusive). This powder is produced by a method which comprises: the production of calcium titanate by subjecting a mixed liquid that contains a sugar, an alkali, a water-soluble compound containing calcium, and a compound which is obtained by deflocculating a hydrolysis poroduct of a titanium compound with use of a monobasic acid to a high-pressure liquid-phase reaction that includes heating to a temperature of from 100°C to 270°C (inclusive),; and a subsequent calcium removal treatment.