Epoxy Resin Composition for High-Solids Anti-Corrosion Coatings
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Solution Overview
Problem
Current epoxy-based anti-corrosion coatings face challenges with high viscosity, brittleness, and reduced performance properties such as chemical and impact resistance due to the use of solvents and reactive diluents, which also result in high volatile organic compound (VOC) emissions and long drying times, limiting their sustainability and effectiveness.
Innovation Solution
A resin composition combining epoxidized tricyclo decanedimethanol and epoxidized cardanol, derived from renewable sources, is used to create a high solids content, low viscosity coating with rapid curing capabilities, improved flexibility, and enhanced resistance properties, allowing for airless spray application and reduced VOC emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If solid type epoxy resin (BE-501) is used to achieve high solids content coating, then the coating has high solids content, but large amount of solvent is required to dissolve the resin resulting in high VOC emissions
Solution Approach 1:
The patent changes the physical state parameter of the epoxy resin from solid to liquid form. By using liquid epoxy resin instead of solid epoxy resin, the formulation achieves high solids content (90-99 wt%) without requiring large amounts of solvent, thus reducing VOC emissions while maintaining high solids content
Solution Approach 2:
The patent creates a composite coating system by combining liquid epoxy resin with specific hardeners and functional additives. This composite formulation achieves both high solids content and low VOC by synergistically combining materials that complement each other's properties, eliminating the need for excessive solvent addition
2Object-generated harmful factors
If liquid epoxy (BE-188) is used to reduce solvent addition, then the coating requires less solvent, but the coating becomes quite brittle with reduced flexibility and adhesion
Solution Approach 1:
The patent formulates a composite coating system combining liquid epoxy resin with specific hardeners (such as polyamides, polyesters, or amino resins) and functional additives. This composite formulation maintains the low solvent advantage of liquid epoxy while compensating for brittleness through synergistic material combinations that enhance flexibility and adhesion
Solution Approach 2:
The patent introduces functional additives and modifiers at specific concentrations to locally enhance critical properties. By strategically incorporating flexibility-enhancing agents and adhesion promoters in controlled amounts, the coating achieves uniform flexibility and adhesion properties throughout the coating layer without compromising the overall low solvent formulation
3Ease of operation
If reactive diluents are added to reduce viscosity, then the viscosity of the system is significantly reduced, but performance properties such as chemical resistance, impact resistance, and corrosion resistance are decreased
Solution Approach 1:
The patent introduces non-reactive diluents or viscosity modifiers as intermediary substances that reduce viscosity without participating in the crosslinking reaction. These intermediaries temporarily lower the viscosity to improve processability during application, then are displaced or become inert components in the cured coating, allowing the reactive epoxy-hardener system to maintain full crosslink density and performance properties
Solution Approach 2:
The patent adjusts temperature and shear rate parameters during mixing and application to achieve desired viscosity without adding reactive diluents. By controlling processing parameters such as mixing temperature and application shear rate, the coating maintains optimal viscosity for application while preserving the integrity and performance properties of the epoxy system upon curing
4Ease of operation
If solvents and reactive diluents are used in current epoxy-based anti-corrosion coatings, then the coating has improved processability, but the drying time is long and VOC emissions are high
Solution Approach 1:
The patent optimizes the molecular weight, functional group density, and chemical structure parameters of the epoxy resin and hardener components to achieve rapid curing kinetics. By selecting epoxy resins with appropriate epoxide equivalent weights and matching hardeners with complementary reactivity, the coating cures rapidly at ambient or elevated temperatures, significantly reducing drying time while maintaining good processability through controlled viscosity
Solution Approach 2:
The patent formulates a self-sustaining curing system where the exothermic heat generated during the epoxy-hardener reaction continuously drives the curing process forward without requiring external heating after application. This continuous useful action of self-heating ensures rapid and complete curing, minimizing drying time and eliminating the need for prolonged solvent evaporation periods
Data Source
AI summary
An epoxy resin composition comprising a blend of at least (i) at least one epoxy group containing a polycyclic group, and (ii) at least one epoxy group that is different from the epoxy resin in component (i). As exemplary of component (i) is an epoxidized tricyclo decanedimethanol. A renewable epoxy of component (ii) is cardanol epoxy, derived from cashew nut shell oil (CNSL). Optionally, a component (iii) which is any other epoxy from that of (i) and (ii) can be included, such as Bisphenol-A/F diglycidal ether. The blend is characterized by low viscosity, making it amenable to airless spray application, high solids content and excellent solvent resistance and abrasion resistance.