Laminated Polyester Film Adhesive Layer Antistatic Design

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Solution Overview

Problem

Conventional laminated polyester films exhibit insufficient adhesiveness between the film and print or hard coating layers, particularly under high temperature and humidity conditions, and lack sufficient antistatic properties, which are essential for applications in electronic devices like cell-phone housings.

Innovation Solution

A laminated polyester film with a continuous phase structure comprising acrylic urethane copolymer resin, isocyanate compound, epoxy compound, polythiophene, and anionic structures, which maintains excellent adhesiveness and antistatic properties even after shaping processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional adhesive layer is used in the laminated polyester film, then the film can be manufactured with basic adhesive properties, but the adhesiveness to print layer or hard coating layer becomes insufficient, especially under high temperature and humidity conditions

Engineering Contradiction:
ImproveadhesivenessVSAvoidhygrothermal environment degradation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive layer by incorporating specific polymers (polyester resin with carboxyl groups, acrylic resin with carboxyl groups, and polyurethane resin) in controlled ratios. This chemical parameter modification enables the adhesive layer to maintain strong bonding to both polyester film and print/hard coating layers even in high temperature and humidity environments, resolving the degradation issue.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite adhesive layer by combining multiple resin types (polyester, acrylic, and polyurethane resins) with complementary properties. This composite structure leverages the strengths of each resin: polyester for thermal stability, acrylic for adhesion, and polyurethane for flexibility and moisture resistance, achieving reliable adhesiveness under hygrothermal conditions.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the adhesive layer is made to improve adhesiveness, then bonding strength increases, but static electricity generation occurs during manufacturing, deteriorating handling performance

Engineering Contradiction:
ImproveadhesivenessVSAvoidstatic electricity
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the electrical properties of the adhesive layer by carefully controlling the resin composition and adding antistatic agents. The specific ratio of polyester, acrylic, and polyurethane resins, combined with antistatic additives, adjusts the surface resistivity to a range that prevents excessive static electricity generation while preserving adhesive performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces antistatic agents as intermediary substances within the adhesive layer. These agents act as mediators that dissipate static electricity buildup during manufacturing processes without interfering with the adhesive bonding function, thus resolving the conflict between adhesiveness and static electricity generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the adhesive layer composition is optimized for adhesiveness, then bonding strength improves, but transparency of the laminated film decreases

Engineering Contradiction:
ImproveadhesivenessVSAvoidtransparency
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent optimizes the refractive index matching between the adhesive layer components and the polyester film substrate by selecting resins with compatible optical properties. The controlled composition of polyester, acrylic, and polyurethane resins, along with precise additive levels, ensures the adhesive layer remains optically transparent while maintaining enhanced adhesiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies the principle of local quality by ensuring the adhesive layer has locally optimized properties: chemically active groups for adhesion at the interfaces, while the bulk composition maintains optical clarity. The carboxyl-containing resins provide localized bonding capability without compromising overall transparency.

Inventive Principle:
Principle #3Local quality

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 film achieves high transparency, strong adhesiveness to print or hard coating layers, and effective antistatic properties, ensuring durability and performance in hygrothermal environments.

Implementation Method 1

layer (X) made from acrylic urethane copolymer resin (A), isocyanate compound (B), epoxy compound (C), compound (d-1) having polythiophene structure and compound (d-2) having anion structure

Methodology Applied
Scientific EffectConduction (electrical): Conduction (electrical)

Implementation Method 2

layer (X) made from acrylic urethane copolymer resin (A), isocyanate compound (B), epoxy compound (C)... excellent adhesiveness to print layer or hard coating layer

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentEP2684694B1Laminated polyester film, molding member, compact, and manufacturing method thereof
Publication Date: 2016.03.02 TORAY INDUSTRIES INC
  • EP2684694B1 patent drawingFigure 1~3
  • EP2684694B1 patent drawingFigure 4~6
  • EP2684694B1 patent drawing

AI summary

Provided are a laminated polyester film, a forming member and a formed body obtained using the laminated polyester film, and a manufacturing method thereof. The film has layer (X) comprising acrylic urethane copolymer resin (A), isocyanate compound (B), epoxy compound (C), compound (d-1) having polythiophene structure, and compound (d-2) having anion structure, the layer (X) being provided on at least one side of polyester film, and the layer (X) having a continuous phase structure. The present invention can provide a laminated polyester film having excellent transparency, adhesiveness to a printed layer or a hard coating layer, antistatic properties, and post-forming adhesiveness or antistatic properties, and can also provide a forming member and a formed body obtained using the laminated polyester film.