Oil-Based Inkjet Ink Set for Discharge Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oil-based inkjet inks face challenges with pigment aggregation and discharge stability when used in multi-color printing, leading to nozzle blockages and image quality issues due to the interaction of different inks and liquids, especially after a long idle period.
Innovation Solution
An oil-based inkjet ink set with two or more liquid compositions, where at least one is an oil-based ink, having an initial boiling point of 280°C or higher and a specific gravity difference of 0.005 to 0.012 between compositions, which reduces aggregate accumulation and improves discharge stability and image quality by minimizing satellite contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If two or more different oil-based inks are discharged from a single inkjet head, then the printing system size is reduced and multi-color printing is enabled, but pigment aggregation occurs and discharge stability deteriorates
Solution Approach 1:
The patent changes the physical parameters of the ink compositions, specifically controlling the initial boiling point (280°C or higher) and specific gravity difference (0.005 to 0.012) between different ink compositions. These parameter adjustments prevent pigment aggregation and maintain discharge stability when multiple inks are used in a single inkjet head, resolving the contradiction between system simplification and reliable operation.
2Reliability
If cleaning operations are performed to remove air bubbles and dirt from nozzles, then normal discharge is restored, but aggregates accumulate on the inkjet head surface causing discharge faults
Solution Approach 1:
The patent converts the potentially harmful mixing of different inks on the nozzle plate into a beneficial outcome by carefully controlling the specific gravity difference between ink compositions. This control ensures that even when inks mix during cleaning operations, pigment aggregation is prevented, and the cleaning process can be performed repeatedly without causing discharge faults.
3Productivity
If the inkjet head is left idle for a long period, then the printing system can operate at high speed when needed, but discharge stability deteriorates and abnormal discharge problems occur
Solution Approach 1:
The patent implements preliminary action by formulating inks with specific physical properties (initial boiling point of 280°C or higher and controlled specific gravity) that prevent pigment aggregation and maintain discharge stability during extended idle periods. This preliminary formulation ensures that when the printing system is needed, the inkjet head is already in a stable state ready for high-speed operation.
4Object-generated harmful factors
If the specific gravity difference between ink compositions is too small, then mixing is reduced, but satellite contamination increases due to improper droplet formation
Solution Approach 1:
The patent optimizes the specific gravity difference parameter within a precise range (0.005 to 0.012) to balance two opposing requirements: preventing pigment aggregation by limiting excessive mixing, and reducing satellite contamination by ensuring proper droplet formation. This careful parameter control resolves the contradiction between minimizing aggregation and preventing satellite defects.
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 ink set ensures stable inkjet head performance even after a long idle period and reduces satellite contamination, resulting in improved image quality and reduced show-through and discharge defects.
Implementation Method 1
oil-based inks mainly dry as a result of penetration into the recording medium
Implementation Method 2
because the solvent is difficult to volatilize, nozzle blockages are unlikely to occur
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An oil-based inkjet ink set including two or more liquid compositions, for use with an inkjet head having two or more discharge port arrays, wherein at least one of the two or more liquid compositions is an oil-based inkjet ink, the initial boiling point of each of the two or more liquid compositions is, independently, 280°C or higher, and the difference in the specific gravities of any pair of liquid compositions in the two or more liquid compositions is at least 0.005 but not more than 0.012, is disclosed. A method for producing a printed item is also disclosed.