Thermal Clear Laminate Donor Element Flash Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal transfer donor elements face the issue of 'flash' where the protective transparent film prematurely separates from the donor ribbon, leading to irregular edges and faults in thermal dye images, and current solutions using colloidal silica are expensive.
Innovation Solution
A thermal transfer donor element with a polymeric support coated with a thermal transferable protective transparent film comprising poly(vinyl acetal), cellulose acetate propionate, and colloidal silica, where the molecular weight of the second polymer is greater than poly(vinyl acetal), and the weight ratios of poly(vinyl acetal) to the second polymer and colloidal silica are optimized to reduce the amount of colloidal silica needed while maintaining film properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If colloidal silica is used to reduce flash, then the flash problem is reduced, but the cost increases
Solution Approach 1:
The patent changes the chemical composition parameters of the protective transparent film by specifying precise weight ratios of poly(vinyl acetal) (50-70 wt%), second polymer (20-40 wt%), and colloidal silica (10-20 wt%). This optimized parameter combination reduces flash while controlling costs through reduced reliance on expensive colloidal silica compared to conventional formulations.
Solution Approach 2:
The patent creates a composite protective transparent film combining multiple materials: poly(vinyl acetal) as the primary binder, second polymer (cellulose acetate propionate or poly(vinyl acetal)) as a co-binder, and colloidal silica as a flash-reducing additive. This composite approach achieves flash reduction through synergistic material interaction while managing cost through balanced composition.
2Reliability
If more colloidal silica is used to prevent flash, then flash is reduced, but the amount of expensive material increases
Solution Approach 1:
The patent optimizes the concentration parameter of colloidal silica to a specific range (10-20 wt% of total film dry weight) rather than using high amounts. This optimized parameter achieves effective flash reduction while minimizing the quantity of expensive colloidal silica required.
Solution Approach 2:
The patent uses poly(vinyl acetal) and second polymer as cost-effective substitute materials that partially replicate the flash-reducing function of colloidal silica, thereby reducing the overall quantity of expensive material needed while maintaining protective performance.
3Reliability
If the protective transparent film is made more stable to prevent premature separation, then flash is reduced, but the film composition becomes more complex
Solution Approach 1:
The patent employs a composite film system with poly(vinyl acetal) as the primary binder and second polymer (cellulose acetate propionate or poly(vinyl acetal)) as a co-binder. This composite approach enhances film stability and prevents premature separation through synergistic bonding, while the structured composition approach manages complexity through defined material roles.
Solution Approach 2:
The patent controls the molecular weight parameter of the second polymer to be greater than that of poly(vinyl acetal), and specifies the weight ratio of poly(vinyl acetal) to second polymer as at least 5:1 and up to 12:1. These parameter specifications optimize film stability while maintaining manageable composition complexity through quantitative control.
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 provides a protective transparent film that reduces 'flash' without increasing costs, using up to 50% less colloidal silica while maintaining image quality and stability, ensuring optimal separation and handling of thermal transfer donor elements and final image prints.
Implementation Method 1
a thermal transfer donor element that can be used to transfer transparent protective films onto thermal receiver elements using thermal transfer means
Implementation Method 2
Heat can be used to drive the colorants deeper into the receiver element
Data Source
AI summary
A thermal transfer donor element has a polymeric support having at least a portion thereof coated with a thermal transferable protective transparent film. This film comprises: (1) a poly(vinyl acetal) in an amount of at least 50-70 weight %, (2) a second polymer, and (3) colloidal silica. In addition, (a) the molecular weight of the second polymer is greater than the molecular weight of the poly(vinyl acetal), (b) the weight ratio of the poly(vinyl acetal) to the second polymer is at least 5:1 and up to and including 12:1, (c) the weight ratio of colloidal silica to the second polymer is at least 1.5:1 and up to and including 3:1, and (d) the amount of colloidal silica is at least 10 weight % and up to and including 20 weight %, based on total thermal transferable protective transparent film dry weight.