2. “All Epoxies Are Not The Same”
Presented to
Paint Applicator Division
by
Tony Ring
3.
4. What is Epoxy?
The epoxide group, also termed as, oxirane or ethoxyline group,
is a 3 member ring containing 2 carbons and an oxygen.
Epoxy resin is defined as a molecule containing more than one
epoxide group
5. Bis-A Epoxy
Most common epoxy resins are Diglycidyl Ethers produced from
a reaction between Epichlorohydrin with Bisphenol A
6. Epoxy History
The first commercial attempts to prepare resins from
epichlorohydrin occurred in 1927 in the United States.
Credit for the first synthesis of Bisphenol A based epoxy resins are
shared by Dr. Pierre Castan of Switzerland and Dr. S.O. Greenlee
in the United States in 1936.
Hexion, Dow and Huntsman are the largest producers of Epoxy
Resins in the US with many foreign suppliers as well.
7. Other Epoxy Types
Other important glycidyl epoxies made from various alcohol
containing compounds
Phenolics: Mono-functional diluents, Bis-F and Novalac Resins
Glycols: Poly-functional diluents and Flexibilizers
Alcohols: Mono-functional diluents
Another class of epoxies is cycloaliphatic and aliphatic resins. These
are non glycidyl epoxies that are formed by peroxidation of olefinic
double bonds. They are used in UV cured formulations and outdoor
applications. They are a minor segment of the market
8. Curing Agents
The epoxy group reacts with various molecules commonly
know as curing agents to form highly cross linked thermoset
polymers
Common curing agents are:
Amines
Polyamides
Amidoamines
Anhydrides
Lewis Acids
Organic Acids
Phenols
Thiols
9. Epoxy Reaction
A typical epoxy amine Reaction is outlined below:
The remaining nitrogen protons continue to react to form the final ridge 3-D Network
10. Epoxy Properties
Properties of optimally formulated cured epoxy systems
– Low shrinkage
– High shear and tensile strength
– Will bond to a large verity of substrates
– Low level of creep under sustained load
– Good thermal resistance
– Good electrical insulator
– Chemical and solvent resistance
– Stiffness
– Good gap filling properties
– Low or no VOCs present in formulations
– Wide formulation latitude possible
– Low cost to performance ratio
11. Property Modifications
There are countless ways epoxy compound’s properties can be
modified by adding various materials, such as:
– Mineral fillers (ex. talc, silica, alumina, etc.)
– Flexibilizers
– Diluents (functional and external)
– Pigments
– Thickeners
– Accelerators
– Adhesion promoters
– Impact modifiers
– Tougheners
12. Property Modifications (cont)
Modifications are made to:
– Improve performance
• Less rigid and brittle
• Decrease cure time
• Increased peel strength, etc.
– Improve processing convenience
– Reduce health hazards
– Adjust mix ratios
– Reduced cure times and temperature for one part systems
– Reduce costs
13. Epoxy Applications
Epoxy systems are widely used. Several applications areas are:
Aerospace Electronics (FR-4) Industrial Assembly
Transportation Paint Applicators Composites
Flooring Filament Winding Pultrusion
Countertops Coatings Primers Secondary Containment
Marine Paints Can Coatings Coil Coatings
Carbon And Glass
Composites
Tools, Molds, Dies
Attachment
Motor and Equipment
Mounting
Replace Welds and
Metal Fasteners
Castings Transformers
14. Formulating for Performance
Epoxy adhesives can be formulated to meet the performance
requirements of almost any application
The key factor is to have the right epoxy for the application at hand
The formulator must understand the end use, application method
and performance requirements.
With that knowledge, epoxies can be:
Very rigid or flexible Fast curing or slow curing
Very hard or soft Opaque or clear
Very thick or thin Permanent or temporary
Electrical isolator or conductor One part or two part
Cured at room temperature,
elevated temperature or with U.V.
Light
Cured underwater
And the list goes on ….
