OMICURE U-52, an aromatic substituted urea, is intended for use as a latent accelerator for the dicyandiamide cure of epoxy resins. The addition of OMICURE U-52 to epoxy/ dicy formulations produces shelf stable one part products which cure in shorter times and/or at lower temperatures. Of the CVC substituted ureas, methylene bis (phenyl dimethyl urea) provides the best combination of acceleration, long shelf life and maintenance of cured properties in dicy cured DGEBA. OMICURE U-52M represents the micronized grade of OMICURE U-52. Suggested use levels of OMICURE U-52 in DGEBA/DICY are < 5 phr. At 5 phr curing can be accomplished in about one hour at 100°C and in less than five minutes at temperatures > 150°C. Room temperature shelf lives (doubling of viscosity) are longer than six months. Cure times and shelf lives are dependent on the composition of the formulated product and your particular end application. Some of the factors which can effect shelf life are formulation ingredients and compounding parameters. Ingredients in which OMICURE U-52 is insoluble at processing and storage temperatures will enhance overall storage stability. OMICURE U-52 can be incorporated into your formulation concurrent with the dicy addition.
|Particle Size, min. % through a 325 mesh screen||80|
|Moisure Content, Max||0.7|
|Melting Point, °C||220 - 230|