Epoxy Adhesive Composition for Impact and Low-Temperature Strength

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Epoxy resin-based adhesives used in the automotive industry lack sufficient impact strength and adhesion at low temperatures, such as -40°C, and do not maintain strength uniformly across a wide temperature range.

Innovation Solution

An adhesive composition comprising one or more epoxy resins, a modified epoxy resin with a polyether structure, core-shell rubber in secondary particles, and an epoxy curing agent, which provides excellent adhesion, impact, and shear strength from -40°C to 80°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If epoxy resin-based adhesives are used for metal-metal or metal-plastic joining, then adhesion strength and heat resistance are improved, but impact strength and low-temperature adhesion are insufficient

Engineering Contradiction:
Improveadhesion strengthVSAvoidimpact strength and low-temperature adhesion
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a composite adhesive system combining epoxy resin with polybutadiene-styrene-acrylonitrile (PBSA) copolymer and core-shell rubber particles. This composite formulation integrates the high strength and heat resistance of epoxy with the impact resistance and low-temperature flexibility of rubber modifiers, achieving uniform performance across -40°C to 80°C temperature ranges

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the epoxy resin system by incorporating specific ratios of PBSA copolymer (5-20 parts by weight per 100 parts epoxy resin) and core-shell rubber (3-15 parts by weight per 100 parts epoxy resin), adjusting the chemical composition parameters to achieve optimal balance between adhesion strength, impact resistance, and low-temperature performance

Inventive Principle:
Principle #35Parameter changes

2Strength

If epoxy resin-based adhesives are designed for high strength, then they lack uniform strength across wide temperature ranges (-40°C to 80°C)

Engineering Contradiction:
Improveadhesion strengthVSAvoidtemperature range uniformity
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent adjusts the glass transition temperatures of the adhesive components by selecting PBSA copolymer with Tg of -60°C to -40°C and core-shell rubber with Tg of -80°C to -50°C, ensuring the adhesive maintains flexible chain mobility and strong adhesion across the wide temperature range from -40°C to 80°C

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The multi-component composite system combines epoxy resin (for high-temperature strength), PBSA copolymer (for low-temperature flexibility), and core-shell rubber (for impact resistance across temperatures), creating synergistic effects that maintain uniform strength properties throughout the operating temperature range

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3825378B1Adhesive composition
Publication Date: 2025.07.16 LG CHEM LTD
  • EP3825378B1 patent drawingFigure 1~2
  • EP3825378B1 patent drawing

AI summary

The present application relates to an epoxy-based adhesive composition. The present application can provide excellent adhesion strength, peel strength and impact-resistant strength uniformly over a wide temperature range.