Core-Shell Ink Particles with Tg Differential for Nozzle Clogging
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Solution Overview
Problem
Existing ink jet recording technologies face issues with image fixation and nozzle clogging due to the use of core-shell particles with crosslinked structures, which affect the stability and abrasion resistance of images on recording media.
Innovation Solution
An ink composition featuring a core-shell polymer particle with a glass transition temperature difference of 30°C or more between the core and shell portions, where the core portion has a Tg of 0°C or less and the shell portion has a Tg of 20°C or more, preventing nozzle adhesion and enhancing image stability and abrasion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a core-shell particle with a crosslinked shell structure is used, then image storage stability is improved, but image fixation deteriorates
Solution Approach 1:
The patent changes the chemical structure parameter of the shell resin from a crosslinked structure to a non-crosslinked structure. This parameter change resolves the contradiction by maintaining storage stability while improving image fixation, as the non-crosslinked shell allows better adhesion to the recording medium without compromising the structural integrity needed for storage stability.
Solution Approach 2:
The patent uses a composite resin emulsion containing both the non-crosslinked shell resin and a thermoplastic resin. This composite material approach allows the shell portion to provide fixation improvement while the thermoplastic resin contributes to storage stability, thereby resolving the contradiction between these two properties.
2Strength
If urethane resin is used in the shell portion, then image fastness is improved, but nozzle recovery deteriorates
Solution Approach 1:
The patent changes the resin type parameter from urethane resin to non-crosslinked resin in the shell portion. This parameter change improves nozzle recovery by preventing clogging while maintaining adequate image fastness through the combination of shell resin and thermoplastic resin components.
Solution Approach 2:
The patent employs a shell resin that does not form permanent crosslinked structures, allowing the ink to be more easily discharged and the nozzles to recover. This approach prioritizes operational ease (nozzle recovery) while maintaining sufficient image fastness through the overall emulsion composition.
3Stability of the object's composition
If a tri-block copolymer is used, then discharge stability is improved, but nozzle recovery deteriorates
Solution Approach 1:
The patent changes the molecular structure parameter of the resin from a tri-block copolymer to a non-crosslinked resin composition. This parameter change maintains discharge stability through proper emulsion formulation while improving nozzle recovery by eliminating the clogging issues associated with tri-block copolymers.
4Strength
If crosslinked polymers are used, then image abrasion resistance is improved, but image fixation deteriorates
Solution Approach 1:
The patent changes the chemical structure parameter from crosslinked polymers to non-crosslinked resins in the shell portion. This parameter change improves image fixation while maintaining adequate abrasion resistance through the combined action of the shell resin and thermoplastic resin in the emulsion.
Solution Approach 2:
The patent uses a composite resin emulsion where the non-crosslinked shell resin provides good fixation and the thermoplastic resin contributes to abrasion resistance. This composite approach resolves the contradiction by distributing the functional requirements across different resin components.
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 composition ensures stable discharge from recording head nozzles and improves image abrasion resistance by forming a hydrate layer and dissolving upon heating, preventing nozzle clogging and enhancing image durability.
Implementation Method 1
the shell portion is immune to the temperature changes associated with discharge of the ink and forms a stable hydrate layer around itself
Implementation Method 2
when the recoding medium after the image has been drawn by the ink is heated to a predetermined temperature, not only the shell portion but also the core portion is dissolved, and the surface of the image is coated mainly with the polymer that forms the core portion
Data Source
AI summary
An ink composition for ink jet recording contains a polymer particle that has a core portion and a shell portion on a surface of the core portion. The core portion has a glass transition temperature of 0° C. or less, and the shell portion has a glass transition temperature of 20° C. or more. The difference between the glass transition temperature of the core portion and that of the shell portion is 30° C. or more.