Layered Protective Transfer Sheet Resolving Adhesion-Durability Trade-off
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Solution Overview
Problem
Existing protective layer transfer sheets and intermediate transfer media face challenges in balancing durability and foil tearing properties, with low interlayer adhesiveness leading to delamination and reduced abrasion resistance, and insufficient chemical durability such as solvent and plasticizer resistance.
Innovation Solution
The use of a protective layer transfer sheet with a layered structure comprising a first protective layer containing an epoxy-cured resin with a glass transition temperature of at least 60°C and a second protective layer with a specific polyester resin, enhancing interlayer adhesiveness and chemical durability, while maintaining good foil tearing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is formed on the receiving layer to improve durability, then abrasion resistance and chemical durability are improved, but interlayer adhesiveness deteriorates causing delamination
Solution Approach 1:
The patent applies parameter changes by carefully controlling the glass transition temperature (Tg) of the reactive resin in the protective layer to be 60°C or higher, and adjusting the equivalent ratio of epoxy groups to functional groups between 0.5-2.0. These parameter optimizations ensure sufficient interlayer adhesiveness while maintaining the protective layer's durability, preventing delamination issues.
Solution Approach 2:
The patent uses composite materials by combining epoxy-cured resin with specific reactive resins (acrylic polyol resin, polyester polyol resin, or polyether polyol resin) having Tg≥60°C. This composite approach creates a protective layer that simultaneously achieves high interlayer adhesiveness and excellent durability against abrasion, solvents, and plasticizers.
2Reliability
If the protective layer uses cured resin to improve chemical durability, then solvent resistance and plasticizer resistance are improved, but foil tearing property deteriorates
Solution Approach 1:
The patent applies parameter changes by controlling the equivalent ratio of epoxy groups to functional groups within 0.5-2.0 and selecting reactive resins with Tg≥60°C. These parameter optimizations ensure the cured resin maintains sufficient foil tearing property while achieving excellent chemical durability against solvents and plasticizers.
Solution Approach 2:
The patent applies local quality by creating a protective layer with specific local characteristics - using epoxy-cured resin that provides chemical durability in the bulk while maintaining foil tearing capability through controlled crosslinking density and resin selection, allowing different regions of the protective layer to exhibit appropriate properties.
3Strength
If a protective layer transfer sheet with epoxy-cured resin is used to improve interlayer adhesiveness, then delamination is prevented, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-forming the protective layer with the appropriate resin composition and crosslinking characteristics on the transfer sheet before the actual transfer process. This preliminary preparation ensures that when the protective layer is transferred to the receiving layer, the interlayer adhesiveness is already optimized, simplifying the overall manufacturing process.
Solution Approach 2:
The patent applies parameter changes by optimizing the equivalent ratio of epoxy groups to functional groups (0.5-2.0) and selecting reactive resins with specific Tg values (≥60°C). These parameter optimizations ensure that the protective layer achieves high interlayer adhesiveness through controlled chemical reactions, simplifying the curing process and reducing manufacturing complexity.
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 simultaneously improves the foil tearing, physical, and chemical durability of the protective layer, preventing delamination and enhancing the overall performance of the protective layer on transfer receiving articles.
Implementation Method 1
a protective layer transfer sheet with a layered structure comprising a first protective layer containing an epoxy-cured resin
Implementation Method 2
the protective layer is transferred onto the receiving layer by using a thermal head or heating roll or the like
Data Source
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AI summary
The purpose is to provide a protective layer transfer sheet and an intermediate transfer medium, in which the protective layer has excellent foil tearing property during transfer and in which sufficient durability can be imparted to the thermally transferred image. The above problem is solved by a protective layer transfer sheet in which a transferable protective layer (20) is provided on one surface of a substrate (1) so as to be peelable from the substrate (1), wherein the transferable protective layer (20) has a layered structure in which a first protective layer (3A), and a second protective layer (3B) which is in contact directly with the first protective layer (3A), are provided in this order from the substrate (1) ; the first protective layer contains an epoxy-cured resin in which a reactive resin having a functional group capable of reacting with an epoxy group and having a glass transition temperature (Tg) of not less than 60°C is reacted with and cured by an epoxy curing agent; and the second protective layer (3B) contains a polyester resin having a number-average molecular weight (Mn) of not less than 8000 and a glass transition temperature (Tg) of not less than 45°C.