Abstract: A heat curable epoxy adhesive composition has been developed which is substantially insoluble in cold hydraulic fluid before it is cured and resistant to degradation in hot hydraulic fluid after it is heat cured. The adhesive comprises a diglycidyl ether of bisphenol-A, a lesser amount of an epoxy novolac resin and a catalytic amount of 2-ethyl-4-methyl imidazole curing agent. The adhesive is particularly adapted to automatically and permanently calibrate the relief pressure of check valves in hydraulic systems.

Abstract: A heat curable epoxy adhesive composition has been developed which is substantially insoluble in cold hydraulic fluid before it is cured and resistant to degradation in hot hydraulic fluid after it is heat cured. The adhesive comprises a diglycidyl ether of bisphenol-A, a lesser amount of an epoxy novolac resin and a catalytic amount of 2-ethyl-4-methyl imidazole curing agent. The adhesive is particularly adapted to automatically and permanently calibrate the relief pressure of check valves in hydraulic systems.

Abstract: Novel epoxy compositions and a method of using them to make bonded rare earth-iron alloy magnets have been developed. The epoxy resins are polyglycidyl ethers of polyphenol alkanes that have high glass transition temperatures. The epoxy resin is provided in the form of a powder containing a suitable amount of a latent imidazole curing agent. The powder is mixed with rare earth-iron alloy particles, the mixture is compacted, and the resultant compact is heated to melt the powder and activate the curing agent. The alloy particles in the resultant magnet body are exceptionally resistant to flux loss upon aging.

Abstract: A method has been developed to use a structural epoxy adhesive to bond together surfaces of phosphated steel electrodeposited with an organic primer. The specially formulated epoxy adhesive contains a cross-linkable epoxy novolac resin, an epoxy reactive diluent, and an imidazole curing agent substituted in at least one position with an alkyl or a hydroxyalkyl group. The amount of the curing agent used in the formulation is much lower than that in a conventional two-part epoxy adhesive such that the adhesive will not attack or degrade the primer layer to weaken the bond strength. The reactive diluent used reduces the viscosity of the mixed adhesive system to facilitate dispersion and wetting of the adhesive on the coated steel surface. Bond strength achieved by this method is adequate for automotive structural applications and is capable of withstanding extended exposure to humidity, salt spray, and other hostile automotive environments without appreciable loss.

Abstract: A method and composition have been developed for providing wear resistant surfaces on tools used to stamp sheet metal. The composition is based on liquid epoxy novolac resin having a functionality greater than two filled with an inorganic powder having very high hardness. The epoxy constituent is cross linked and cured in two stages: it is first cured at room temperature with an aliphatic amine curing agent until it is hardened and is then toughened by an elevated temperature cure initiated by an imidazole curing agent. The composition may be used to cast an entire tool or as a surface coating layer for a less durable base.

Abstract: A novel adhesive has been developed that is particularly adapted for use in bonding automotive components made of sheet molding compound. It is comprised of suitable amounts of cross-linkable epoxy novolac resin; an epoxy flexibilizer; natural and colloidal silica; and an imidazole curing agent substituted in the one position with a short chain hydroxyalkyl group. The adhesive cures to a high bond strength in three minutes at 150.degree. C. It is resistant to degradation due to temperatures up to 200.degree. C., salt spray, humidity and water soak.

Abstract: In a preferred embodiment, a spreadable, thermosetting automotive body solder is comprised of 100 parts of an epoxy resin adduct of epichlorohydrin and bisphenol A, 25 to 40 parts liquid polysulfide rubber, 0.02 to 0.06 moles of an imidazole curing agent substituted in the 2-position with a hydrocarbon group, and a filler system consisting of 5 to 20 parts aluminum powder, 10 to 20 parts ion-exchanged clay, 3 to 6 parts wetting agent for the clay, and 70 to 130 parts fibrous or plate talc average particle size 3 microns or less. The composition is workable for several hours at room temperatures but cures in a few minutes at temperatures over 100.degree. C. The filler system provides the body solder with thixotropic properties at room temperatures, and sag resistance in both the cured and uncured states at temperatures up to 200.degree. C. The solder is corrosion resistant without other additives.