Ink-Jet Recording Method with Oxygen-Controlled Curing
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Solution Overview
Problem
Ink-jet recording methods using actinic ray curable inks on non-absorptive recording media, such as transparent films or vapor-deposited papers, face issues with image quality due to liquid deviation and color bleeding, particularly when white or clear inks are used for undercoating, resulting in poor adhesion between the upper and lower layers.
Innovation Solution
An ink-jet recording method involving the use of an actinic ray curable ink set with a first ink containing titanium oxide and a gelling agent, and a second ink with a colorant, where both layers are cured simultaneously under controlled oxygen concentrations of 10 volume% or less, ensuring improved adhesion and curing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a white ink or clear ink is used for undercoating on non-absorptive recording media, then the visibility and uniformity of the image is improved, but the adhesion between the upper layer and lower layer deteriorates
Solution Approach 1:
The patent changes the oxygen concentration parameter during curing from atmospheric levels (21% oxygen) to a controlled low oxygen environment (10 volume% or less). This parameter change prevents oxygen inhibition of polymerization, enabling the colored ink to cure properly and adhere to the white or clear undercoating layer, thus resolving the adhesion problem while maintaining image quality
Solution Approach 2:
The patent applies a preliminary undercoating layer of white or clear ink before applying the colored ink. This preliminary action creates a uniform base that improves image visibility, and when both layers are cured together under low oxygen conditions, it ensures proper adhesion between the layers without compromising the image quality benefits
2Shape
If the gelling agent amount in white ink is increased to suppress droplet coalescence, then the droplet texture is improved, but the adhesion to colored ink deteriorates due to excessive surface deposition
Solution Approach 1:
The patent changes the curing environment parameter (oxygen concentration) to prevent oxygen inhibition. This allows the gelling agent to function properly without precipitating excessively on the surface, as the curing proceeds uniformly throughout the ink layer. The result is maintained droplet texture with improved adhesion to the colored ink layer
3Quantity of substance
If titanium oxide is used as white pigment for its high hiding power, then the shielding property is improved, but the interaction with gelling agent is reduced leading to poor adhesion
Solution Approach 1:
The patent changes the oxygen concentration parameter during curing to eliminate oxygen inhibition. This enables the photopolymerization to proceed to completion even in the presence of titanium oxide particles that interfere with gelling agent interaction. The result is that the high hiding power of titanium oxide is maintained while achieving sufficient adhesion through complete curing of both ink layers
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
This approach enhances the adhesion between the upper and lower layers, improving the abrasion resistance and image quality by equalizing the curing shrinkage of both layers, even when white or clear inks are used for undercoating.
Implementation Method 1
after ink droplets are landed on a recording medium, an actinic ray, for example, an ultraviolet ray is irradiated and cured to form an image
Implementation Method 2
it is less susceptible to oxygen inhibition and has good curing properties
Data Source
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AI summary
Provided is an ink-jet recording method using an actinic ray curable ink-jet ink set having a first ink-jet ink containing at least titanium oxide and a gelling agent, and a second ink-jet ink containing a colorant other than titanium oxide, the ink-jet recording method containing the steps of: forming a lower print layer by printing the first ink-jet ink; forming an upper print layer on the lower print layer by printing the second ink-jet ink; and curing the lower print layer and the upper print layer by irradiating the lower print layer and the upper print layer with actinic rays, wherein an oxygen concentration in an atmosphere to which the actinic rays are irradiated is controlled to be 10 volume% or less in the step of curing the lower print layer and the upper print layer.