Epoxide Adhesive Composition with Insoluble Imidazole Accelerator
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Solution Overview
Problem
Single-component adhesives used in electronics manufacturing face challenges with premature aging and high hardening temperatures, limiting their shelf life and adhesive properties, especially when used with materials requiring low creepage current resistance values.
Innovation Solution
A composition comprising a mixture of bifunctional or polyfunctional epoxide resins with an imidazole derivative hardening accelerator, which is not soluble at temperatures below 50°C, allowing for a single-component adhesive that hardens at 100°C and meets class I insulating material standards with improved adhesion and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If single-component adhesives use hardening accelerators soluble at room temperature, then shelf life is extended, but hardening temperature increases to above 150°C
Solution Approach 1:
The patent changes the solubility parameter of the hardening accelerator by selecting an imidazole derivative that is specifically insoluble in the epoxide resin mixture at temperatures below 50°C. This parameter change allows the accelerator to remain dormant during storage (extending shelf life) and become active only when heated to the required hardening temperature of 100°C or higher, thus resolving the contradiction between shelf life and hardening temperature.
2Temperature
If hardening temperature is reduced to below 150°C, then electronic component properties are preserved, but creepage current resistance decreases to class II or IIIa
Solution Approach 1:
The patent employs a composite formulation combining a specific epoxide resin mixture (containing both aliphatic/cycloaliphatic/aromatic epoxides and polyfunctional epoxides) with an imidazole derivative hardening accelerator. This composite material system achieves a synergistic effect where the low hardening temperature (100°C) is maintained while the cross-linking structure provides sufficient creepage current resistance (>600V, class I), resolving the contradiction between temperature and reliability.
3Productivity
If imidazole derivatives soluble below 50°C are used, then hardening is accelerated, but shelf life is reduced to a few days
Solution Approach 1:
The patent applies dynamics by making the hardening accelerator's solubility and activity temperature-dependent. The imidazole derivative is selected to be insoluble at storage temperatures (below 50°C), keeping the system stable during storage. When heated to the hardening temperature (100°C), the accelerator becomes soluble and chemically active, providing rapid hardening. This dynamic behavior resolves the contradiction between hardening speed and shelf life.
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 composition achieves a shelf life of at least three months at room temperature and provides creepage current resistance values greater than 600V, with excellent adhesion and thermal stability, suitable for electronic components.
Implementation Method 1
the hardening accelerator is an imidazole derivative, which is not soluble in the epoxide resin mixture at temperatures of below 50° C.
Implementation Method 2
a composition for an adhesive material is provided, which comprises at least one epoxide resin mixture and a hardening accelerator
Data Source
AI summary
A composition for an adhesive material, comprising at least one epoxide resin mixture and a hardening accelerator, in which the epoxide resin mixture has 25 to 80% by weight of a first epoxide resin—whereby the first epoxide resin is a bifunctional aliphatic, cycloaliphatic or aromatic epoxide resin—and 12.5 to 40% by weight of a second epoxide resin—whereby the second epoxide resin is a polyfunctional aliphatic or aromatic epoxide resin—and in which the hardening accelerator is an imidazole derivative, which is not soluble in the epoxide resin mixture at temperatures of below 50° C.