LOCTITE CAT 21

Harmonization Code : 8529.90 | Parts solely or principally used for TV, radio, and transmission

LOCTITE CAT 21

Main features

  • Low-Viscosity Polyoxyalkylene Amine Curative
  • One-Hour Pot Life
  • Large-Mass Epoxy Castings

Product Description

LOCTITE® CAT 21 is a low-viscosity polyoxyalkylene amine curing agent designed for use with compatible epoxy resin systems. The hardener is particularly suited for large-mass casting applications and provides excellent impact resistance, thermal shock resistance and non-crystallizing storage stability. It can be cured at room temperature or with elevated-temperature post-curing and delivers reliable performance in epoxy systems operating across a broad temperature range.

Key Features & Benefits

  • Polyoxyalkylene amine epoxy curing agent.
  • Low-viscosity formulation for easy processing.
  • Non-crystallizing during storage.
  • Suitable for large-mass epoxy castings.
  • Good impact resistance after cure.
  • Good thermal shock resistance.
  • Supports room-temperature and heat-cure schedules.

Recommended Applications

  • Large-volume epoxy casting systems.
  • Industrial encapsulation and potting.
  • Electrical and electronic resin systems.
  • Applications requiring thermal shock resistance.
  • General-purpose epoxy curing applications.
Product Family

LOCTITE CAT 21

Catalog Product

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TDS, SDS & Technical Documents

Technical Specifications

No specifications available.

Additional Information

Technical Properties

As-Supplied / Before-Processing Properties

Property Value Unit Condition
Technology Polyoxyalkylene Amine Epoxy Curing Agent
Appearance Dark Amber As supplied
Viscosity 65 mPa·s (cP) 25°C
Specific Gravity 1.03 25°C
Pot Life (100 g Mass) 1 hour 25°C
Shelf Life 548 days 25°C storage
Cure Type Room Temperature or Heat Cure Recommended process
Technical Properties

After-Processing / Final-State Properties

Property Value Unit Condition / Method
Recommended Cure Schedule 16 - 24 hours 25°C initial cure
Post Cure 6 hours 65 to 85°C
Continuous Operating Temperature -65 to +120 °C Typical cured epoxy system
Impact Resistance Good Product characteristic
Thermal Shock Resistance Good Product characteristic
Large Mass Casting Capability Yes Designed for large epoxy castings
Crystallization Resistance Non-Crystallizing Storage characteristic

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