Electrophotographic Image Varnishing With Active-Ray Roll Coating
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Solution Overview
Problem
Existing image forming methods using electrophotographic techniques face issues with varnish coatability and adhesiveness to fixed images due to the varnish repelling effect, despite enhancements in toner adhesiveness and primer layers, as they do not adequately control surface energies.
Innovation Solution
Applying an active ray-curable liquid substance with specific viscosity and contact angle within a defined coordinate region, using a roll coating method, to improve coatability and adhesiveness by adjusting surface tension and viscosity of the liquid substance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a varnish coating is applied to a fixed image obtained through electrophotographic image forming, then the image quality and durability are improved, but the coatability is lower and varnish repelling occurs
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface energy parameters of the varnish liquid. Specifically, it sets the contact angle between the varnish and image to 0° and the surface tension of the varnish liquid to 20-35 mN/m, ensuring optimal wetting and coating properties on the electrophotographic image surface.
2Strength
If the varnish coatability is enhanced by using a toner with high adhesiveness, then the adhesiveness between the fixed image and varnish layer is improved, but the surface energy control is insufficient
Solution Approach 1:
The patent transitions from qualitative toner selection to quantitative surface energy control. By defining specific ranges for contact angle (0°) and surface tension (20-35 mN/m), it provides precise manufacturing parameters that ensure consistent adhesiveness and coating quality.
3Ease of manufacture
If a primer layer is provided on the toner image before applying varnish, then the coatability of varnish is enhanced, but the process complexity increases
Solution Approach 1:
The patent extracts and eliminates the intermediate primer layer step from the coating process. By directly controlling the surface energy parameters of the varnish liquid itself (contact angle 0°, surface tension 20-35 mN/m), it achieves good coatability without requiring additional primer layers, thereby simplifying the overall process.
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
Enhances the coatability and adhesiveness of the varnish to the image by optimizing the surface energy balance through specific viscosity and contact angle adjustments, improving post-press processing properties.
Implementation Method 1
the coatability and the adhesiveness to an image of an active ray-curable liquid substance as a varnish... are further improved... by appropriately controlling the surface energies of the varnish and the image
Implementation Method 2
when a contact angle A (°) with an image is taken on a horizontal axis and a viscosity V (mPa·s) is taken on a vertical axis in a coordinate system for the active ray-curable liquid substance
Implementation Method 3
an active ray-curable liquid substance... contains a reactive monomer and an acrylic resin polymer
Data Source
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AI summary
Provided is an image forming method, wherein after image formation with a printing material containing a release agent, a specific active ray-curable liquid substance is applied with a roll coating method, and when a coordinate (A, V) of a point indicating a contact angle A (°) and a viscosity V (mPa·s) corresponding to the contact angle Av(°) is plotted in a coordinate system having a contact angle A (°) on a horizontal axis and a viscosity V (mPa·s) on a vertical axis, the coordinate is included in a coordinate region R (A, V) on an upper side of a contact angle-viscosity curve represented by a formula on a right side of a specific expression.