Epoxy Dual Cure Resin for Additive Manufacturing
Solution Overview
Problem
Conventional additive manufacturing techniques are limited by the availability of materials with diverse properties, restricting the potential of three-dimensional fabrication, particularly in terms of material properties such as tensile strength, scratch resistance, and chemical resistance.
Innovation Solution
The development of epoxy dual cure resins comprising a photoinitiator, monomers/prepolymers, epoxy resin, optional hardeners, and fillers, which are solidified by light exposure and further cured through heating or microwave irradiation, enabling the creation of three-dimensional objects with enhanced mechanical and chemical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional photo curable resins are used for additive manufacturing, then layer formation can be achieved through UV or visible light irradiation, but the material properties such as tensile strength, scratch resistance, and chemical resistance are limited
Solution Approach 1:
The patent employs composite resin formulations combining epoxy resins with acrylate monomers and oligomers. The epoxy component provides superior mechanical strength, tensile properties, and chemical resistance, while the acrylate components enable photopolymerization. This composite approach allows the material to achieve enhanced mechanical properties unattainable with conventional single-component photo curable resins.
Solution Approach 2:
The patent modifies the chemical composition parameters of the resin system by incorporating specific ratios of epoxy resins, acrylate monomers, and oligomers. By adjusting these compositional parameters and using dual-cure mechanisms (photocuring followed by thermal or microwave curing), the material achieves transformed mechanical and chemical resistance properties suitable for demanding applications.
2Strength
If conventional photo curable resins are used, then additive manufacturing can be performed with standard UV or visible light irradiation, but the scratch resistance and chemical resistance of the fabricated objects are insufficient
Solution Approach 1:
The resin composition integrates epoxy resins known for their excellent chemical resistance and scratch hardness with photopolymerizable acrylate groups. This composite structure provides both the mechanical durability (scratch resistance) and chemical inertness required for reliable performance in harsh environments, while maintaining compatibility with additive manufacturing processes.
Solution Approach 2:
The patent alters the chemical composition to include epoxy resins with specific molecular structures and crosslink densities that enhance scratch resistance and chemical resistance. The dual-cure mechanism (photocuring plus thermal/microwave curing) further transforms the material parameters to achieve the desired reliability and durability properties.
3Strength
If a dual cure resin system is used comprising both photopolymerizable and epoxy components, then enhanced mechanical properties can be achieved, but the process complexity increases with multiple curing steps
Solution Approach 1:
The photopolymerizable acrylate components undergo preliminary curing during the additive manufacturing process, forming a green part with sufficient structural integrity for handling. This preliminary action allows the object to be fabricated layer-by-layer, after which thermal or microwave curing completes the crosslinking to achieve final mechanical properties, thereby dividing the curing process into manageable stages.
Solution Approach 2:
The resin system is designed to perform multiple functions: it enables photopolymerization for additive manufacturing, provides structural integrity during fabrication, and undergoes subsequent thermal/microwave curing to achieve final mechanical properties. This multi-functionality reduces the need for separate materials for different process stages, simplifying the overall system despite the multi-step curing process.
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 described method and resin compositions enable the production of three-dimensional objects with high tensile strength, scratch resistance, and chemical resistance, suitable for various applications including electronic devices and mechanical components.
Implementation Method 1
monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light
Implementation Method 2
heating and/or microwave irradiating said three-dimensional intermediate sufficiently to further cure said resin
Data Source
AI summary
An epoxy dual cure resin useful for additive manufacturing of three-dimensional objects includes: (i) a photoinitiator; (ii) monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light; (iii) optionally, a light absorbing pigment or dye; (iv) an epoxy resin; (v) optionally, but in some embodiments preferably, an organic hardener co-polymerizable with the epoxy resin; (vi) optionally but preferably a dual reactive compound having substituted thereon a first reactive group reactive with said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, and a second reactive group reactive with said epoxy resin (e.g., an epoxy acrylate); (vii) optionally a diluent; (viii) optionally a filler; and (ix) optionally, a co-monomer and/or a co-prepolymer. Methods of using the same in additive manufacturing are also described.