Energy savings plus mechanical reinforcement and rheology control

General Purpose Epoxy-Mercaptan Adhesives

Adhesives Formulation

Applicable Type

Reactive Adhesives , Epoxy Adhesives

Applicable Base Polymer

Epoxies (EP)

Applicable Industrial Sectors

Electrical & Electronic Bonding

Applicable Base Polymer Properties

The polymercaptans can be used to cure epoxy resin systems quickly. The primary advantages of epoxy adhesives cured with mercaptan curing agents are the following: - Rapid Cure of Epoxies - Low-Temperature Cure - Thin-Film Cure - Low Toxicity - Light Color - Excellent Adhesion - 1:1 mix ratio – not critical - Acceleration ability with other curatives, e.g. amines, polyamides, anhydrides, etc.

Typical Formulation Ingredients

Ingredient

Parts by weight

Part A:

Epoxy resin (Epon 828, Momentive Specialty Chemicals)

xxx

Part B:

Mercaptan (GPM-800, Gabriel Performance Products)

xxx

Accelerator (GPM-30, Gabriel Performance Products)

(Source: Gabriel Performance Products)

Typical Properties

Properties

Mix ratio by weight, Part A : Part B

xxxxxxxx

Gel time, mins

• 50 gm mass

xxx

• 0.015” film

xxx

Hardness, Shore D after:

• 5 mins

• 20 mins

• 1 hr

• 24 hrs

Lap shear strength, psi:

• Aluminum, etched

xxxx

• Mild steel, sandblasted

xxxx

• TPE polyester, abraded

xxx

• Thermoplastic olefin, abraded

xxx

Processing

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Resulting Properties

These adhesives are rapid curing epoxy adhesives processing variable viscosity depending on the filler concentration. The bond will set to a handling strength in approximately 5 mins at room temperature and will develop greater than 1,000 psi tensile shear strength in approximately several hours. Practical cure rates can be achieved at temperatures as low as 4°C. The major disadvantages of mercaptan curing agents are their odor, skinning, and low heat deflection temperature.