Metal-Doped Epoxy Card Core for Metallic Feel and RFID Compatibility

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Solution Overview

Problem

Existing transaction cards that mimic a metallic look and feel are costly and lack efficient manufacturing processes to incorporate metal components without compromising durability and functionality.

Innovation Solution

A process involving a metal-doped curable epoxy, comprising metal particles in a binder, is used to form a core layer that constitutes a significant portion of the transaction card, which is then cured and optionally coated, with features like booster antennas and payment modules integrated, to achieve a metallic appearance and functionality at a lower cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If full metal cards are used to achieve metallic look and feel, then durability and metallic appearance are improved, but cost increases significantly

Engineering Contradiction:
ImprovedurabilityVSAvoidcost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses a composite material consisting of metal particles dispersed in a plastic matrix to create a core layer that combines the metallic appearance and durability of metal with the cost-effectiveness and manufacturability of plastic. This composite approach allows the card to achieve metallic properties without using solid metal throughout, thereby reducing cost while maintaining the desired aesthetic and functional characteristics.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If metal particles are added to plastic to create metallic appearance, then metallic look and feel are improved, but manufacturing complexity increases

Engineering Contradiction:
Improvemetallic appearanceVSAvoidmanufacturing process
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent controls the manufacturing process by specifying parameters such as particle size (less than 10 microns), particle concentration, and curing conditions for the epoxy resin. These parameter controls ensure consistent metallic appearance and physical properties while maintaining compatibility with standard plastic card manufacturing equipment, thereby managing manufacturing complexity through defined specifications rather than complex processes.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If high density metal particles are used to increase card weight, then metallic feel is improved, but card brittleness increases

Engineering Contradiction:
Improvecard weightVSAvoidbrittleness
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent creates a localized metal-rich core layer that provides the desired weight and metallic appearance only where needed, while the surrounding plastic layers maintain flexibility and prevent brittleness. This local concentration of metal particles in the core layer allows the card to achieve metallic characteristics without the entire structure becoming brittle, as the plastic matrix continues to provide structural flexibility.

Inventive Principle:
Principle #3Local quality

4Strength

If metal components are incorporated into the card, then durability and metallic appearance are improved, but RFID signal transmission may be interfered with

Engineering Contradiction:
ImprovedurabilityVSAvoidRFID communication
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses the plastic matrix as an intermediary material that separates the metal particles from the RFID antenna, preventing direct interference while maintaining the metallic appearance and durability of the core layer. The plastic acts as a non-conductive barrier that allows RFID signals to pass through without being blocked by the metal particles, thus resolving the conflict between metallic properties and RFID functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 transaction cards with a metallic look and feel, enhanced durability, and functional integrity at a reduced cost, while maintaining compatibility with RFID and contactless payment technologies.

Implementation Method 1

curing the metal-doped curable epoxy to form a hardened core of cured metal-doped epoxy

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP3849767B1Metal-doped epoxy resin transaction card and process for manufacture
Publication Date: 2026.04.01 COMPOSECURE LLC
  • EP3849767B1 patent drawingFigure 1
  • EP3849767B1 patent drawingFigure 2A~2C
  • EP3849767B1 patent drawingFigure 3~4

AI summary

A transaction card (200), and processes for the manufacture thereof, having a core layer (250, 300, 500, 630), optionally, one or more layers or coatings (260, 270, 610, 630, 640, 650) over the core layer, and at least one of a magnetic stripe (240), a machine readable code, and a payment module chip (280) disposed in or on the card and suitable for rendering the card operable for conducting a transaction. The core layer (250) comprises a metal-doped cured epoxy comprised of metal particles (255) distributed in a binder consisting essentially of a cured, polymerized epoxy resin (257), the core comprising greater than 50%, preferably greater than 75%, and more preferably greater than 90%, of the weight and/or volume of the card. In some embodiments, the core includes a metal insert (310) enveloped with the metal-doped curable epoxy, wherein the periphery of the epoxy extends beyond the periphery of the metal insert and has material properties more conducive to cutting or punching than the metal insert.