Decorative Sheet Primer Layer Hydroxyl Value for Raven Blackness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resin molded articles using transfer-type decorative sheets struggle to achieve a deep, glossy black color with raven blackness due to limitations in the exposure and integration of the decorative layer, leading to insufficient color and gloss in the final product.
Innovation Solution
A decorative sheet comprising a base material with a protective layer, a primer layer formed from a cured acryl-based resin with a hydroxyl value of 44 mg KOH/g or less, and an isocyanate-based curing agent, and a decorative layer containing a black pigment, which allows for the vivid display of deep colors like raven blackness by ensuring a low L* value of 2.5 or less on the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a transfer-type decorative sheet is used with conventional primer layers, then the decorative layer can be transferred to the resin molded article, but the color and gloss display is insufficient to achieve deep raven blackness
Solution Approach 1:
The patent changes the chemical parameters of the primer layer by specifying a hydroxyl value of 44 mg KOH/g or less and using an isocyanate-based curing agent, which optimizes the layer's properties to enhance color and gloss display while achieving deep raven blackness in the decorative layer
Solution Approach 2:
The patent creates a composite structure by combining the primer layer with specific resin compositions (acryl-based resin with controlled hydroxyl value) and curing agents (isocyanate-based), forming a multi-layer composite that achieves superior color and gloss properties that cannot be obtained with single materials
2Illumination intensity
If the decorative layer is covered by surface protective layer and support base material in sheet state, then the decorative sheet has structural integrity, but the decorative layer cannot be exposed to display its color and gloss
Solution Approach 1:
The patent applies the decorative layer to the resin molded article before final assembly, allowing the decorative layer to be properly positioned and integrated into the structure where it can be exposed and display its color and gloss properties effectively
Solution Approach 2:
The patent separates the functions of different layers: the support base material provides structural integrity, the surface protective layer provides protection, and the decorative layer provides color and gloss display, allowing each layer to perform its specific function optimally
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 enables the production of resin molded articles with a black portion having a very low brightness, effectively displaying raven blackness, enhancing the design properties and color appearance of the final product.
Implementation Method 1
a primer layer formed from a cured acryl-based resin with a hydroxyl value of 44 mg KOH/g or less, and an isocyanate-based curing agent
Data Source
Figure 1~2
Figure 3
AI summary
The present invention provides a decorative sheet capable of vividly displaying deep-color designs including raven blackness. The decorative sheet includes a base material, and at least a protective layer, a primer layer, and a decorative layer laminated in this order on the base material, wherein the decorative layer contains a black pigment and the primer layer is formed of a cured product of a resin composition containing a resin A having a hydroxyl value of 44 mgKOH/g or less.