Epoxy Resin Composition With Safer Anhydride Curing
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Solution Overview
Problem
Existing epoxy resin curing agents, particularly amines and anhydrides, pose health risks and have limitations such as high curing temperatures, long curing periods, and inferior alkali and solvent resistance, with some anhydrides being labeled as respiratory sensitizers and listed as Substances of Very High Concern (SVHC).
Innovation Solution
A method involving mixing specific ratios of epoxy resins, anhydride curing agents, accelerators, and fillers under controlled conditions to produce a composition with reduced weight loss and improved mechanical and electrical properties, using safe, REACH-compliant anhydrides to minimize health risks and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If amine curing agents are used to cure epoxy resins, then the curing process is efficient and widely applicable, but health risks increase due to skin irritation, sensitization, and potential carcinogenicity
Solution Approach 1:
The patent extracts and removes the harmful amine component from the curing system while retaining the essential curing function through alternative chemistry (anhydride-based curing), thereby eliminating health risks associated with amine exposure
Solution Approach 2:
The patent employs safer, short-term curing agents (anhydrides) that can be handled with minimal safety concerns compared to persistent harmful amines, reducing long-term health risks while maintaining curing effectiveness
2Temperature
If anhydride curing agents are used to cure epoxy resins, then thermal resistance and electrical properties improve, but curing temperature increases and curing period extends
Solution Approach 1:
The patent modifies the anhydride curing system by selecting specific anhydride types and optimizing their ratios with epoxy resins to achieve lower curing temperatures and reduced curing times while maintaining the thermal resistance benefits
Solution Approach 2:
The patent creates a composite curing system combining epoxy resin with specifically selected anhydrides (glutaric, dodecenyl succinic, nonenyl succinic) in optimized proportions to achieve balanced performance with reduced curing requirements
3Temperature
If anhydride curing agents are used to cure epoxy resins, then thermal deformation temperature increases, but alkali resistance and solvent resistance deteriorate
Solution Approach 1:
The patent adjusts the chemical composition parameters by selecting specific anhydride types (glutaric, dodecenyl succinic, nonenyl succinic) and optimizing their ratios to achieve a balance between thermal deformation temperature and chemical resistance properties
Solution Approach 2:
The patent develops a composite epoxy-anhydride system where the specific combination of epoxy resin and anhydride creates synergistic effects that maintain both thermal performance and chemical resistance
4Productivity
If certain anhydride compounds are used as curing agents, then curing performance is achieved, but regulatory compliance worsens due to R42 labeling and SVHC listing
Solution Approach 1:
The patent extracts and eliminates the problematic anhydride compounds (hexahydrophthalic anhydride, cyclohexane dicarboxylic anhydride) that carry R42 labels and SVHC listings, replacing them with compliant alternatives that maintain curing performance
Solution Approach 2:
The patent employs safer, regulatory-compliant anhydride alternatives that can be used without the restrictive labeling and regulatory burdens associated with SVHC substances, enabling broader application versatility
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 resulting epoxy resin composition exhibits low weight loss, enhanced mechanical and electrical properties, and compliance with safety regulations, suitable for manufacturing electrical components with improved thermal aging behavior and reduced health hazards.
Implementation Method 1
epoxy resins must be cured or cross-linked by polymerization into hard, infusible solids by the addition of substances that are called curing agents or hardeners
Implementation Method 2
curing the mixture obtained after step (b) at 80°C-140°C for 10 minutes to 10 hours
Data Source
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AI summary
A method for preparing an epoxy resin composition is disclosed. The method comprises mixing an epoxy resin selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac based resin, cycloaliphatic epoxy resin, and a combination thereof in the range of 35-65% w/w, and an anhydride curing agent selected from the group consisting of glutaric anhydride, dodecenyl succinic anhydride, nonenyl succinic anhydride, and a combination thereof, in the range of 35-65% w/w while continuously stirring at a temperature in the range of 15-100°C for 15-120 minutes; adding to the mixture, one or more accelerator selected from the group consisting of amine, a metal halide, a phosphine, an acetylacetonate, an imidazole compound and a combination thereof, in the range of 0.3-1.5% by weight of the mixture and one or more filler selected from the group consisting of silica, wollastonite and a combination thereof, in the range of 190-230 % by weight of the mixture; and curing the mixture obtained after step (b) at 80°C-140°C for 10 minutes to 10 hours to obtain the epoxy resin composition. The weight loss of the composition obtained from the disclosed method is less than 1.8% after aging for 1000 hrs at 180°C based on IEC 60216. Epoxy resin compositions and products comprising said compositions are also disclosed.