Polyimide Varnish Composition for Wire Adhesion and Heat Resistance
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Solution Overview
Problem
Existing polyimide resins face challenges in achieving simultaneous improvements in heat resistance, insulation, mechanical properties, and adhesion to conductors, often leading to appearance defects in insulating coatings.
Innovation Solution
A polyimide varnish is formulated with an azine-based diamine monomer, specifically 1,3,5-triazine-2,4-diamine derivatives, to enhance adhesion to wires, incorporating a dianhydride monomer like pyromellitic dianhydride and a first diamine monomer such as 4,4′-diaminodiphenyl ether, with a balanced composition to ensure excellent adhesion and physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If general polyimide resin is used to form insulating coating, then heat resistance and insulation properties are improved, but adhesion to conductors deteriorates causing appearance defects
Solution Approach 1:
The patent uses a composite diamine system combining aromatic diamine (for heat resistance) and cyc aliphatic diamine (for adhesion) to create a polyimide resin that simultaneously achieves both heat resistance and conductor adhesion. This composite approach allows the resin to exhibit properties of both constituent diamines, resolving the contradiction between heat resistance and adhesion.
Solution Approach 2:
The patent modifies the chemical composition parameters of the diamine monomers by specifying a weight ratio range (95:5 to 50:50 of aromatic to cyc aliphatic diamine). By adjusting these compositional parameters, the resin can be optimized to balance heat resistance and adhesion properties according to specific application requirements.
2Use of energy by moving object
If polyimide resin composition is modified to improve adhesion, then adhesion to conductors is improved, but other physical properties may deteriorate
Solution Approach 1:
The patent carefully controls the compositional parameters of the diamine monomers, specifying that aromatic diamine content should be 50-95 wt% and cyc aliphatic diamine content should be 5-50 wt%. This parameter optimization ensures that adhesion improvement does not compromise the thermal and mechanical properties essential for insulating coating performance.
Solution Approach 2:
The patent introduces specific functional groups (hydroxyl or carboxyl groups) at specific positions on the cyc aliphatic diamine structure to enhance adhesion locally at the conductor interface, while the overall polyimide matrix maintains its heat resistance and mechanical strength through the aromatic diamine component.
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 varnish provides improved adhesion to conductors, preventing peeling and enhancing the overall performance of the insulating coating without compromising heat resistance and mechanical strength.
Implementation Method 1
performing solution polymerization on aromatic dianhydride and aromatic diamine or aromatic diisocyanate to prepare a polyamic acid derivative
Implementation Method 2
followed by ring-closure dehydration at high temperature and imidization
Data Source
AI summary
The present invention provides a polyimide varnish comprising a dianhydride monomer and a diamine monomer as polymerization units, wherein the diamine monomer comprises a first diamine monomer and a second diamine monomer, and the second diamine monomer is represented by the following Chemical Formula 1. The polyimide varnish of the present invention has excellent adhesion and adherence to wires such as copper, and thus has excellent usability as an insulating coating material for an electric wire, etc.in Chemical Formula 1 above,A may be unsubstituted or substituted, and is hydrogen, halogen, C1-C6 alkyl, phenyl, (C1-C6 alkylene)-(C3-C5 heteroaryl), (C1-C6 alkylene)-COOH, or —OH, wherein the substitution means substitution with halogen, C1-C3 alkyl, C1-C3 haloalkyl or oxo (═O).