Solvent-Free Wire Enamel Using UV-Crosslinked Polyesterimide

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Solution Overview

Problem

Existing wire enamel compositions lack the necessary heat resistance for modern applications in coil and motor construction, particularly at temperatures above 155°C, and solvent-based processes are energy-intensive and prone to coating issues.

Innovation Solution

A solvent-free wire enamel composition using extrudable polyesterimide-containing binders produced from polyols, polycarboxylic acids, imide-forming components with unsaturated bonds, and crosslinkable structural elements that can be crosslinked via UV or IR radiation, allowing for thermal and photochemical post-crosslinking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solvent-based painting process is used, then good coating coverage is achieved, but energy consumption increases and heat resistance above 155°C is not sufficient

Engineering Contradiction:
Improveheat resistanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention changes the chemical composition parameters of the binder by incorporating crosslinkable structural units (unsaturated bonds) that enable post-crosslinking reactions. This transforms the thermal properties of the coating, raising the glass transition temperature and heat resistance above 155°C while eliminating the need for solvent-based application processes, thereby reducing energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite binder system combining polyesterimide base resin with crosslinkable functional groups (acrylate, methacrylate, vinyl, or epoxy groups). This composite structure integrates the thermal stability of polyesterimide with the crosslinking capability of unsaturated bonds, achieving both high heat resistance and solvent-free processing.

Inventive Principle:
Principle #40Composite materials

2Reliability

If thermoplastic materials are used for extrusion coating, then processing is simplified, but heat resistance is insufficient for temperatures above 155°C

Engineering Contradiction:
Improveheat resistanceVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention incorporates crosslinkable structural units (unsaturated bonds) into the binder composition before extrusion. This preliminary incorporation allows the material to be processed like thermoplastics during extrusion, then subsequently crosslinked through UV or IR radiation to achieve the required heat resistance above 155°C, combining ease of manufacture with high reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention replaces purely mechanical/thermal processing of thermoplastics with a combination of extrusion followed by photochemical or thermal crosslinking. The crosslinkable structural units enable chemical bonding that locks in the coating structure, providing heat resistance that thermoplastic alone cannot achieve while maintaining extrusion processing advantages.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If multiple painting and baking cycles are performed, then pore-free film is obtained, but process time and energy consumption increase

Engineering Contradiction:
Improvecoating qualityVSAvoidprocess time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention enables continuous crosslinking through UV or IR radiation immediately after extrusion, eliminating the need for multiple intermittent heating and cooling cycles. The crosslinkable structural units react continuously under radiation to form a pore-free, crosslinked film in a single pass, reducing process time while maintaining coating quality.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The invention replaces repeated thermal baking cycles with a single UV or IR radiation curing step. The photochemical or rapid thermal crosslinking mechanism achieves pore-free film formation in one continuous action rather than through multiple mechanical heating/cooling cycles, significantly reducing process time and energy consumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 wire enamels with enhanced heat resistance suitable for temperatures above 155°C, meeting current standards for winding wires while reducing energy consumption by eliminating the need for solvent-based processes.

Implementation Method 1

crosslinkable by means of UV or IR radiation after extrusion

Methodology Applied
Scientific EffectUV radiation crosslinking: Photopolymerisation

Implementation Method 2

crosslinkable by means of UV or IR radiation after extrusion

Methodology Applied
Scientific EffectIR radiation heating: Infrared Radiation

Implementation Method 3

thermal and photochemical post-crosslinking

Methodology Applied
Scientific EffectThermal crosslinking: Heating

Data Source

PatentEP2742511B1Solvent-free wire enamel composition
Publication Date: 2020.09.02 ELANTAS

AI summary

The invention relates to a solvent-free wire enamel composition containing extrudable binders containing polyesterimide, produced from polyols, polycarboxylic acids, imide-forming components, and structural elements, which can be cross-linked after the extrusion.