Abstract: The invention includes an electronic animal tag of two pieces, one incorporating the UHF, and preferably RFID, electronic identification portion, the other incorporating means that will press the UHF portion against the ear of an animal and keep it pressed there throughout its lifetime.

Abstract: Acyl-ethyleneurea terminated compounds based on the reaction of ethyleneurea with dibasic acids or methyl esters of dibasic acids or cyclic anhydrides are useful as modifying agents, cure accelerators and blocking agents with tertiary amine catalysts for epoxy resins. As epoxy modifiers, they react with epoxy resins at 120 degrees C. without a catalyst to produce modified epoxies having increased viscosity and increased reactivity and solvent power. When combined with a suitable tertiary amine catalyst, they are useful as cure accelerators at a low cure temperature of about 80 degrees C. When combined with a tertiary amine, they form complexes which provide superior latency of the epoxy-hardener mixture at 20 degrees C. Heat-curable epoxy-based compositions treated with the materials of the invention and processes whereby the various novel compositions of the invention are made, are also described.

Abstract: An epoxy-hardener system is provided having relatively long latency periods combined with relatively short cure times at low cure temperatures. The hardeners of the present invention are ureidoamines and their derivatives, which are chelates of ureido compounds and amines. The ureidoamines are prepared by reacting an amine with the ureido compound and aqueous formaldehyde without a catalyst. Complexes of ureidoamine hardeners with various blocking agents are prepared in the melt. The hardener is prevented from curing the epoxy by the reaction between the hardener and the blocking agent. The blocked hardener is then blended with the epoxy, usually by warming the mixture briefly at about 50-60 degrees C.