White Ink Coating via Controlled Precipitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic printing inks for non-white substrates face challenges in achieving consistent white appearance and high opacity due to high conductivity and background levels, which are not adequately addressed by increasing pigment loading.
Innovation Solution
A method involving heating a polymer resin in a carrier fluid to dissolve it, suspending white pigment particles, and cooling at a controlled rate to precipitate the resin and form a coating on the particles, resulting in a white liquid electrophotographic ink composition with reduced particle conductivity and increased opacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If pigment loading is increased to improve opacity, then opacity is improved, but conductivity increases and background levels worsen
Solution Approach 1:
A polymer coating shell is formed around each pigment particle through controlled precipitation, creating a flexible protective layer that reduces conductivity and suppresses background levels while maintaining the pigment's opacity-enhancing properties
Solution Approach 2:
The polymer precipitation process uses controlled cooling rates (0.1-5°C per minute) to optimize the coating formation parameters, achieving the right balance between opacity, conductivity, and background level suppression
2Productivity
If polymer resin is dissolved and precipitated rapidly to increase productivity, then productivity is improved, but manufacturing precision deteriorates
Solution Approach 1:
The precipitation process uses dynamic temperature control with a controlled cooling rate range (0.1-5°C per minute), allowing the system to adapt between slow precise coating formation and faster production cycles based on requirements
Solution Approach 2:
By controlling the cooling rate parameter within a specific range, the process optimizes the balance between precipitation speed and coating quality, ensuring uniform polymer distribution on pigment particles while maintaining productive throughput
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 effectively encapsulates white pigment particles, reducing particle conductivity and background levels while enhancing opacity, leading to a more efficient and less energy-intensive production process with improved printing results.
Implementation Method 1
heating a polymer resin in a carrier fluid to dissolve it
Implementation Method 2
cooling the carrier fluid at a rate of 2 °C/hr or less to effect precipitation of the polymer resin from the carrier fluid
Implementation Method 3
cooling the carrier fluid at a rate of 2 °C/hr or less to effect precipitation of the polymer resin from the carrier fluid
Data Source
Figure 1
AI summary
A method for coating pigment particles is provided, the method comprising heating a polymer resin in a carrier fluid to dissolve the polymer resin; suspending in the carrier fluid white pigment particles to be coated; and cooling the carrier fluid at a rate of 2 °C/hr or less to effect precipitation of the polymer resin from the carrier fluid such that a coating of the resin is formed on the pigment particles, thereby producing the white liquid electrophotographic ink composition.