Frozen adhesives

First use of electrically conductive epoxies Premixed, frozen adhesives introduced by Ablestik Laboratories, Epoxy Technology, and Amicon Reduced ion content epoxies and polyimides Introduction of epoxy preforms First high-purity RTV silicone adhesives from G.E. and Dow Coming... 

In general, specific processes for formulating adhesives are proprietary with the adhesives manufacturer. However, some basic methods and considerations for formulating paste, film, and frozen adhesives are given here. 

Frozen adhesives are transported in containers with dry ice at 80 °C and must be stored at —40 °C until ready for use, at which time only the amount needed, is thawed and dispensed. The adhesive should be thawed to room temperature in its original closed container since thawing while exposed to air causes moisture condensation and absorption. After dispensing, any unused adhesive should not be refrozen since a portion of its pot life has been expended. Adhesives that are shipped in dry ice or stored at —40 °C may contain a temperature indicator, a cube of red material that melts if the temperature exceeds —40 °C. 

Rocheleau H. Frozen Adhesive Advantages in Electronic Manufacturing. Electronic... 

See the later section in this article on Adhesive Processes for comments about storing premixed and frozen adhesives. Between Tgo and gei g, the liquid resin will react without gelation until its continuously rising glass-transition temperature becomes coincidental with the cure temperature, at which stage vitrification begins and the reaction may become diffusion controlled. Note that gei g is the temperature at which gelation and vitrification occur simultaneously. 

Rocheleau, H., Frozen Adhesive Advantages in Electronic Manufacturing, Electronic Mfg., pp. 18-19 (Jul. 1988)... 

Ablestik Laboratories. Ablestik Solves the Quality Control Problem with Preserved Frozen Adhesives, Company Literature. Gardena, CA Henkel Corp. 2010. 

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