Decorative Sheet Primer Layer Adhesion for Complex Curved Surfaces
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Solution Overview
Problem
Conventional decorative sheets with thin metal film layers struggle with low adhesion to resin layers, leading to delamination and poor moldability when used on complex, three-dimensionally curved surfaces, especially when stretched beyond a certain draw ratio during molding.
Innovation Solution
A decorative sheet with a laminated structure comprising a base material layer, a first primer layer with a cured resin having a glass transition point of -30°C to 40°C, and a thin metal film layer, which enhances adhesion and allows for high three-dimensional moldability by preventing delamination and fading of the metal film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a thin metal film layer is used to create a metallic-tone design, then the aesthetic appearance is improved, but the adhesion to the resin layer deteriorates, causing delamination and floating during molding
Solution Approach 1:
The patent introduces a primer layer as an intermediary between the resin layer and the thin metal film layer. This primer layer serves as a mediator that enhances adhesion between the two layers, preventing delamination and floating during molding while preserving the metallic-tone appearance of the thin metal film.
Solution Approach 2:
The patent creates a composite structure consisting of multiple layers: a resin layer, a primer layer, and a thin metal film layer. This composite material approach combines materials with different properties to achieve both good adhesion (through the primer layer) and aesthetic metallic appearance (through the thin metal film layer).
2Adaptability or versatility
If the decorative sheet is stretched to high draw ratios (150% or more) to follow complicated curved surfaces, then the three-dimensional moldability is improved, but the adhesion between layers deteriorates, causing delamination and floating
Solution Approach 1:
The primer layer acts as a mediator that maintains adhesion between the resin layer and thin metal film layer even when the decorative sheet is stretched to high draw ratios of 150% or more to follow complicated curved surfaces, preventing delamination and floating during high-degree three-dimensional molding.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the primer layer, specifically formulating it with functional groups that enhance adhesion under stress. This parameter change in the primer layer's composition enables it to maintain bonding strength even when the decorative sheet undergoes significant stretching to achieve high three-dimensional moldability.
3Ease of manufacture
If conventional decorative sheets are used on complicated surfaces requiring high stretch, then the manufacturing simplicity is maintained, but the product quality deteriorates due to delamination, floating, and fading of the metal film
Solution Approach 1:
The primer layer serves as an intermediary that prevents delamination, floating, and fading of the metal film during molding of complicated surfaces, thereby improving manufacturing precision without significantly complicating the manufacturing process.
Solution Approach 2:
The patent employs a composite material structure with a specifically formulated primer layer that enhances adhesion and prevents metal film degradation. This composite approach improves product quality (preventing delamination and fading) while maintaining relative manufacturing simplicity through a straightforward lamination 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
The solution provides a decorative sheet that can effectively follow complex surface shapes with high adhesion and resistance to fading, even when stretched significantly, improving the manufacturing process and product quality by preventing delamination and maintaining the metallic tone design.
Implementation Method 1
adhesion between a resin layer (e.g. base material layer, adhesive layer or the like) formed of a resin and a thin metal film layer formed of a metal is low
Implementation Method 2
the first primer layer contains a cured product of a resin having a glass transition point of -30°C to 40°C
Data Source
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AI summary
[Problem] The present invention provides a decorative sheet provided with three-dimensional moldability capable of sufficiently following the shape of a decorative resin molded article having a complicated surface shape. [Solution] A decorative sheet composed of a layered body in which at least a substrate layer, a primer layer, and a thin metal film layer have been layered in sequence, and the primer layer contains a cured material having a resin in which the glass transition point is -30°C to 80°C.