Core-Shell Fluoropolymer Coatings for Metal Adhesion and Low Dielectric Loss

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current electronic telecommunication articles face challenges in achieving high adhesion to metal substrates and optimal electrical properties due to the limitations of random fluoropolymers, which often have non-fluorinated functional groups that hinder adhesion and electrical performance.

Innovation Solution

The development of core shell fluoropolymers comprising tetrafluoroethylene with a high percentage of polymerized units and a thin shell containing functional groups such as nitrile, halogen, sulfur oxide, or perfluorinated alkyl ether, which enhances adhesion and electrical properties by minimizing non-fluorinated groups and providing cure sites for crosslinking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If random fluoropolymers with functional groups are used, then adhesion to metal substrates is improved, but electrical properties (dielectric constant and loss) deteriorate due to non-fluorinated functional groups

Engineering Contradiction:
Improveadhesion to metal substratesVSAvoidelectrical properties
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The fluoropolymer is segmented into core and shell regions with distinct compositions. The core contains fluorinated comonomers for electrical performance, while the shell contains functional groups for adhesion. This spatial segmentation allows both adhesion and electrical properties to be optimized simultaneously without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the fluoropolymer particle have different functional qualities. The shell region is locally optimized for adhesion to metal substrates through functional groups, while the core region is locally optimized for electrical properties through high fluorine content. This local quality differentiation resolves the contradiction between adhesion and electrical performance.

Inventive Principle:
Principle #3Local quality

2Strength

If functional groups are distributed throughout the fluoropolymer, then adhesion to metal substrates is improved, but the amount of non-fluorinated groups increases and deteriorates electrical properties

Engineering Contradiction:
Improveadhesion to metal substratesVSAvoidamount of non-fluorinated functional groups
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The functional groups are segmented and concentrated specifically in the shell region rather than being distributed throughout the entire polymer. This segmentation allows adhesion functionality to be maintained while minimizing the overall quantity of non-fluorinated groups in the bulk material, thereby preserving electrical properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The functional groups are localized to the shell region where they are needed for adhesion, rather than being distributed throughout the polymer. This localization minimizes the volume of non-fluorinated material, maintaining low dielectric constant and loss while providing sufficient adhesion functionality at the interface with metal substrates.

Inventive Principle:
Principle #3Local quality

3Strength

If high content of functional comonomers is used, then adhesion and crosslinking are improved, but melt processability deteriorates

Engineering Contradiction:
Improveadhesion and crosslinkingVSAvoidmelt processability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The polymer is segmented into core and shell with different comonomer compositions. The core uses fluorinated comonomers that maintain processability, while the shell uses functional comonomers for adhesion and crosslinking. This segmentation allows high functional group content in the shell without compromising overall melt processability of the polymer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The functional comonomers are localized to the shell region where adhesion and crosslinking are needed, rather than being distributed throughout the polymer. This local concentration allows high functional group content (improving adhesion) while the fluorinated core maintains good melt processability, resolving the contradiction between adhesion performance and ease of manufacture.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20240343898A1Core shell fluoropolymers with functional groups suitable for copper and electronic telecommunications articles
Publication Date: 2024.10.17 3M INNOVATIVE PROPERTIES CO

AI summary

Presently described are electronic telecommunication articles comprising core shell fluoropolymers comprising polymerized units of tetrafluoroethylene and no greater than 1 wt. % of polymerized units of comonomer comprising a functional group. The functional groups are typically selected from nitrile, halogen, sulfur oxide, perfluorinated alkyl ether, and carbonyl. The core shell fluoropolymer typically comprises at least 80, 85, 90, 95, 96, 97, 98, 99 wt. % or greater of polymerized units of tetrafluoroethylene. In some embodiments, the core shell fluoropolymer further comprises up to 20 or 25 wt. % of polymerized units of other comonomers, such as hexafluoropropylene (HFP). Also described are methods of making a coated substrate, coated substrates, and core shell fluoropolymers.