Adhesive Coating Composition for Electrical Steel Sheet Laminates

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Solution Overview

Problem

Existing electrical steel sheet laminates require conventional fastening methods like welding, cramping, or interlocking, which can compromise the magnetic properties of the steel sheets.

Innovation Solution

An electrical steel sheet laminate with a fusion layer formed using an adhesive coating composition that enhances adhesive strength between steel sheets without relying on conventional fastening methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional fastening methods (welding, cramping, interlocking) are used to adhere electrical steel sheets, then adhesive strength is achieved, but magnetic properties are compromised

Engineering Contradiction:
Improveadhesive strengthVSAvoidmagnetic properties
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent replaces mechanical fastening methods (welding, cramping, interlocking) with a chemical bonding system using an adhesive coating composition. The coating contains reactive groups that form chemical bonds with the electrical steel sheets, providing adhesion without mechanical intervention that would damage magnetic properties.

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

Solution Approach 2:

The adhesive coating composition acts as an intermediary layer between electrical steel sheets. This intermediate layer provides the bonding function while isolating the steel sheets from direct mechanical or thermal contact that would compromise their magnetic characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If insulating coating film is applied to suppress eddy current, then electrical properties are improved, but adhesion between sheets deteriorates

Engineering Contradiction:
Improveelectrical propertiesVSAvoidadhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The adhesive coating composition is formulated as a composite material containing both insulating components (to maintain electrical properties and suppress eddy currents) and adhesive components (with reactive groups for strong bonding). This composite structure simultaneously provides both required functions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The coating is designed with local quality differentiation: it provides insulating properties at the interface with the steel sheets to suppress eddy currents, while simultaneously providing adhesive properties through reactive groups that bond to the sheet surfaces. Different regions of the coating perform different functions.

Inventive Principle:
Principle #3Local quality

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 improves adhesive strength and maintains the magnetic properties of the electrical steel sheet laminate, offering better magnetism and adhesion at high temperatures.

Implementation Method 1

a fusion layer which is formed by thermal fusion of the adhesive coating layer

Methodology Applied
Scientific EffectThermal fusion: Melting

Data Source

PatentEP4079820B1Electrical steel sheet adhesive coating composition, electrical steel sheet laminate, and method for manufacturing same
Publication Date: 2025.09.10 POHANG IRON & STEEL CO LTD
  • EP4079820B1 patent drawingFigure 1
  • EP4079820B1 patent drawingFigure 2
  • EP4079820B1 patent drawingFigure 3

AI summary

An adhesive coating composition according to one embodiment of the present invention comprises 100 parts by weight of polyethylene acrylate including a repeating unit represented by a following formula (1) and a repeating unit represented by a following formula (2), and 3 to 25 parts by weight of inorganic particles, wherein the polyethylene acrylate contains 75 to 95% by weight of the repeating unit represented by the following formula (1), and 5 to 25% by weight of the repeating unit represented by the following formula (2).