Zoldine ZT-65 5-Hydroxymethyl-1-aza-3,7-dioxabicyclo [3,3,0] octane Dow Chemical-Angus Crosslinking / Coupling / Curing Agents Aminoplaste & Phenoplastes (UF, MUF...) ADHESIVE Hardener for Resorcinol and Tannin Based Wood Bonding Adhesives. ZOLDINES ZT-55 and ZT-65 are stable liquids that eliminate the safety hazards and handling inconvenience associated with paraformaldehyde (Para). These products have low vapor pressures and contain less than 0.1% free formaldehyde, thereby avoiding the fuming and formaldehyde exposure issues associated with Para. ZOLDINES ZT-55 and ZT-65 offer the following key benefits to producers of resorcinol and tannin based wood adhesives: Safety Easy-to-handle liquid products Formaldehyde free (< 0.1% free formaldehyde) Non-fuming and dust free Convenience Low viscosity liquids that are easily pumped, transferred and mixed with other adhesive components Fast/Adjustable Reactivity Higher reactivity than paraformaldehyde (reduced cure temperature and time) Pot life and cure time easily adjusted to meet customer requirements Cure at wide temperature range (reasonable cure rates in cold climates) Excellent Adhesive Performance Oven and ambient cure laminates pass stringent wet strength requirements, such as ASTM D2559 Laminates pass shear strength and wood failure requirements Each of the above benefits will be discussed in detail in this bulletin. ZOLDINE ZT-65 is a low viscosity liquid that is easy and relatively safe to handle. Because of its low viscosity, ZOLDINE ZT-65 mixes readily with other hardener ingredients, producing uniform mixtures. Since the hardener viscosity will typically be low, it may be necessary to add a thickening agent such as carboxymethylcellulose to achieve the desired mix stability and adhesive application viscosity. This is particularly true for ZOLDINE ZT-65 hardeners intended for ambient cure adhesives. In this case, ZOLDINE ZT-65 hardener may require incorporation of a sorbent such as wheat flour. The sorbent will precipitate unless a thickening agent is added. In any case, ZOLDINE ZT-65 hardeners mix easily with resin, and this is especially important in fast curing adhesives. These systems may utilize static mixers, and components that are easily mixed are desirable. Another advantage of ZOLDINE ZT-65 hardeners is that all of the ZT is immediately available for reaction with resin. Para hardeners, on the other hand, are sometimes mixed on-site to avoid precipitation and nonuniformity that can occur upon storage. If the para mix does not set long enough, hydrolysis may be incomplete and not all of the formaldehyde will be available for reaction with resin. The on-site mixing is also inconvenient, and presents safety hazards as already discussed. ZOLDINE ZT-65 can be used as a hardener for resorcinol resin adhesives in the manufacturing of articles such as I-beams (I-joists), laminated beams (glulams), and other engineered wood products. ZOLDINE ZT-65 has achieved commercial success in oven-cure adhesive systems, and has been shown capable of meeting performance requirements (wet delamination, etc.) for ambient cure adhesives as well. Low viscosity, formaldehyde-free oxazolidine. Used as curing agent for phenolic/resorcinol adhesive resins and for resorcinol and tannin based wood bonding adhesives. Offers safety, convenience, fast and adjustable reactivity and very good adhesive performance.