Acrylic Decorative Product Plasma Treated Layer Color Tone Control

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Solution Overview

Problem

Decorative products with acrylic resin transparent members experience unexpected changes in color tone when a metal film is sputtered onto them, particularly becoming yellower when viewed from the opposite side due to the formation of a processed layer that affects light transparency.

Innovation Solution

A processed layer of diamond-like carbon with a thickness less than or equal to 260 nm is formed on the transparent member using plasma treatment, followed by sputtering a metal layer, which increases adhesion and limits color tone changes by adjusting the plasma treatment conditions, including exposure to oxygen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a metal film is sputtered onto an acrylic resin transparent member to form a decorative layer, then the decorative product obtains a three-dimensional aesthetic appeal, but the color tone of the decorative layer becomes yellower when viewed from the transparent member

Engineering Contradiction:
Improveaesthetic appealVSAvoidcolor tone control
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

A processed layer is introduced as an intermediary between the transparent member and the decorative layer. This processed layer, formed by plasma treatment, acts as a mediator that prevents direct interaction between the acrylic resin and the metal film, thereby preventing yellowing while maintaining adhesion and aesthetic appeal.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The plasma treatment parameters (gas type, power, time) are optimized to control the thickness and properties of the processed layer. By adjusting these parameters, the processed layer thickness is controlled to be less than or equal to 260 nm, which limits color tone changes while maintaining adhesion.

Inventive Principle:
Principle #35Parameter changes

2Strength

If a plasma treatment is performed on the acrylic resin surface before sputtering to improve adhesion, then the adhesion between the decorative layer and transparent member is enhanced, but the transparency of the transparent member changes affecting the color tone

Engineering Contradiction:
ImproveadhesionVSAvoidtransparency
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The plasma treatment parameters (gas type, power, time) are optimized to control the thickness and properties of the processed layer. By adjusting these parameters, the processed layer thickness is controlled to be less than or equal to 260 nm, which maintains adhesion while minimizing impact on transparency and color tone.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The structure becomes a composite of transparent member + processed layer + decorative layer. The processed layer, with its diamond-like carbon structure, provides adhesion enhancement while its controlled thickness ensures minimal optical interference, achieving both strong adhesion and maintained transparency.

Inventive Principle:
Principle #40Composite materials

3Strength

If the processed layer thickness is increased to improve adhesion, then the adhesion strength increases, but the color tone changes become more pronounced

Engineering Contradiction:
ImproveadhesionVSAvoidcolor tone stability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The plasma treatment parameters are precisely controlled to limit the processed layer thickness to less than or equal to 260 nm. This parameter optimization achieves the optimal balance between adhesion strength and color tone stability, preventing excessive yellowing while ensuring sufficient adhesion.

Inventive Principle:
Principle #35Parameter changes

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 effectively limits color tone changes and enhances long-term adhesion between the transparent member and the decorative layer, maintaining the original aesthetic appeal while ensuring durability.

Implementation Method 1

The processed layer is formed by performing a plasma treatment on the first surface of the transparent member

Methodology Applied
Scientific EffectPlasma treatment: Plasma

Implementation Method 2

The decorative layer is a metal layer formed on the processed layer formed by performing sputtering

Methodology Applied
Scientific EffectSputtering: Sputtering

Implementation Method 3

The processed layer is a layer having a structure of diamond-like carbon

Methodology Applied
Scientific EffectDiamond-like carbon: Diamond-like Carbon

Data Source

PatentEP3278979B1Decorative product and method of manufacturing decorative product
Publication Date: 2020.09.30 TOYODA GOSEI CO LTD
  • EP3278979B1 patent drawingFigure 1A~2

AI summary

A decorative product (10) includes a transparent member (20) formed from an acrylic resin and a decorative layer (30) arranged on a rear surface (20r) of the transparent member (20). A processed layer (21) is located between the transparent member (20) and the decorative layer (30). The processed layer (21) is formed by performing a plasma treatment on the rear surface (20r) of the transparent member (20). The decorative layer (30) is a metal layer formed on the processed layer (21) formed by performing sputtering. The processed layer (21) has the thickness L of less than or equal to 260 nm.