Fluororesin Coating Composition for Copper Foil Adhesion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing fluororesin coating compositions face challenges in achieving sufficient adhesive properties between the fluororesin coating film and metal substrates, particularly with smooth copper foils having small surface roughness, while also requiring excellent heat resistance and electrical properties.

Innovation Solution

A coating composition containing 2 or more kinds of fluororesins, where at least one fluororesin (I) has a specific number of functional groups (30 to 1,000 per 10^6 main-chain carbon atoms) to enhance adhesive properties, combined with an inorganic filler, surfactant, and liquid medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional fluororesin coating compositions are used, then electrical properties and heat resistance are maintained, but adhesive properties to metal substrates are insufficient

Engineering Contradiction:
Improveadhesive propertiesVSAvoidelectrical properties and heat resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses composite materials by combining multiple fluororesins with different functional groups (carboxyl, hydroxyl, amine groups) in specific proportions. This composite approach allows the coating to simultaneously achieve strong adhesive properties through functional group interactions with metal substrates while maintaining excellent electrical properties and heat resistance characteristic of fluororesins. The synergistic effect of different fluororesin components resolves the contradiction between adhesion and performance reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes key parameters of the fluororesin composition, specifically controlling the number of functional groups (30-1,000 per 10^6 main-chain carbon atoms) and the proportion of different fluororesin types. By optimizing these parameters, the coating achieves sufficient adhesive strength to metal substrates while preserving the electrical and thermal performance required for high-frequency applications.

Inventive Principle:
Principle #35Parameter changes

2Strength

If fluororesin coating is applied to smooth copper foils, then electrical properties are maintained, but adhesive properties deteriorate due to small surface roughness

Engineering Contradiction:
Improveadhesive propertiesVSAvoidsurface roughness
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent introduces fluororesins containing functional groups (carboxyl, hydroxyl, amine) as intermediary substances between the smooth copper foil surface and the fluororesin coating. These functional groups act as chemical mediators that can form strong bonds with the metal substrate even on smooth surfaces, enabling adequate adhesion without requiring surface roughness modification while maintaining electrical properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If multiple fluororesins are combined to improve adhesion, then adhesive properties are enhanced, but composition complexity increases

Engineering Contradiction:
Improveadhesive propertiesVSAvoidcomposition complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent manages composition complexity by precisely controlling key parameters: the number of functional groups (30-1,000 per 10^6 main-chain carbon atoms) and the proportion of different fluororesin types (5-50% by mass). This parameter-based approach simplifies the formulation process and quality control while achieving the desired adhesive enhancement through multiple fluororesin components.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12240988B2Coating composition and laminate
Publication Date: 2025.03.04 DAIKIN INDUSTRIES LTD

AI summary

Provided is an aqueous coating composition capable of forming a fluororesin coating film layer with excellent electrical properties and surface physical properties, and good adhesive properties. A coating composition containing 2 or more kinds of fluororesins, where at least 1 kind of the fluororesin, a fluororesin (I), has a number of functional groups of 30 to 1,000 per 106 main-chain carbon atoms, and where the coating composition further contains an inorganic filler, a surfactant, and a liquid medium.