Liquid Ejection Head Flow Channel Member Swelling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face durability issues when used with inks containing a high proportion of organic solvent, leading to swelling of the flow channel member and variations in ink ejection, resulting in defective printed articles.
Innovation Solution
A liquid ejection head with a flow channel member made from a crosslinked cured product of multifunctional epoxy resin and polyhydric alcohol, where the polyhydric alcohol concentration varies in the thickness direction, providing enhanced strength and adhesion between the substrate and flow channel member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional flow channel member material (photosensitive polyimide, polyamide, or epoxy) is used, then the liquid ejection head can be manufactured with standard materials, but the flow channel member swells when exposed to high proportion organic solvent ink, leading to durability issues and defective printed articles
Solution Approach 1:
The patent uses a composite material consisting of a cured product of a resin composition containing a fluorocarbon compound and a curable epoxy compound. This composite material combines the benefits of fluorocarbon (swelling resistance, chemical inertness) with epoxy resin (adhesion, mechanical strength), resolving the contradiction between durability and swelling resistance by creating a material that exhibits both properties simultaneously.
Solution Approach 2:
The patent changes the chemical composition parameters of the flow channel member material by incorporating fluorocarbon compounds with specific molecular structures (containing CF3 groups or perfluoroalkyl groups) into the epoxy resin system. This parameter change transforms the material's chemical properties to resist organic solvent swelling while maintaining mechanical integrity and adhesion.
2Reliability
If the flow channel member material is made more resistant to organic solvent swelling, then durability improves, but the adhesion strength between the flow channel member and substrate may be compromised
Solution Approach 1:
The cured product of the resin composition containing both fluorocarbon compound and curable epoxy compound creates a composite material that simultaneously provides swelling resistance and strong adhesion. The epoxy component ensures strong bonding to the substrate while the fluorocarbon component provides chemical resistance, resolving the contradiction between durability and adhesion strength.
Solution Approach 2:
The material composition is designed to have different functional characteristics in different aspects: the fluorocarbon segments provide local swelling resistance where they contact the ink, while the epoxy resin segments provide local adhesion where they bond to the substrate. This local differentiation of material properties resolves the contradiction between swelling resistance and adhesion strength.
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 solution ensures stable and long-term ejection of liquid droplets, even with high organic solvent content, by preventing swelling and maintaining consistent ink ejection performance.
Implementation Method 1
forming a layer of a photosensitive resin composition containing a multifunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the molecule thereof for the flow channel member over a substrate; forming a latent image including a flow channel pattern in the layer of the photosensitive resin composition by exposing a pattern
Data Source
AI summary
A liquid ejection head includes a substrate including an energy generating element configured to generate energy used for ejecting a liquid, a flow channel member overlying the substrate and defining a flow channel through which a liquid is supplied, and an ejection opening member overlying the flow channel member and defining an ejection opening through which the liquid supplied through the flow channel is ejected by the energy from the energy generating element. The flow channel member contains a crosslinked cured product of a multifunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the molecular structure, and the concentration of a component derived from the polyhydric alcohol in the flow channel member is lower on the side adjacent to the substrate than on the side adjacent to the ejection opening member.