Amine CS-1246 5-Ethyl-1-aza-3,7-dioxabicyclo [3,3,0] octane 7747-35-5 Dow Chemical-Angus Crosslinking / Coupling / Curing Agents Aminoplaste & Phenoplastes (UF, MUF...) ADHESIVE ANGUS oxazolidines are saturated heterocyclic compounds prepared by reacting ANGUS primary amino alcohols with formaldehyde. Monocyclic or bicyclic oxazolidine ring structures are formed depending on the choice of starting materials. It is therefore possible to synthesize a variety of oxazolidines from ANGUS amino alcohols. ANGUS oxazolidines are highly useful materials for a wide variety of applications. Chemically, they behave as both an aldehyde and as an amine.1 ANGUS oxazolidines can be utilized as alkalinity modifiers, corrosion inhibitors or emulsifiers in formulated products.They can additionally be employed as curing agents or reactive diluents in the production of either acid or alkaline catalyzed polymers. The applications discussed herein merely highlight some of the many uses of ANGUS oxazolidines and should not be considered all-inclusive. Urea- and Melamine-Formaldehyde Resins ANGUS oxazolidines react readily with urea or melamine to form specialty adhesive resins. ANGUS oxazolidines can be used to modify the functional properties of an established urea-formaldehyde or melamine-formaldehyde condensate resin. They also can be used as raw materials in the synthesis of new resins. When utilized as curing agents for these compounds, ANGUS oxazolidines tend to impart greater flexibility and elongation characteristics to the finished product. Resins made from ANGUS oxazolidines and urea have been reported to provide improved solvent resistance. The choice of ANGUS oxazolidine also makes a significant difference in the reactivity or pot life of a given resin formula. AMINE CS-1146 has a medium reactivity. Phenol/Resorcinol Resins ANGUS oxazolidines will react readily with most phenolic compounds. Resorcinol has been shown to be the most reactive, followed by Bisphenol A, both of which will react at ambient temperatures. Phenol itself is the least reactive with ANGUS oxazolidines, generally requiring elevated temperatures for useful reaction rates. Blends of various phenols will give intermediate rates of reaction. Reactivity is also affected significantly by the choice of oxazolidine AMINE CS-1246 has medium reactivity. Paraformaldehyde is commonly used as a hardener for phenol-resorcinol-formaldehyde (PRF) and resorcinolformaldehyde (RF) adhesive resins. The use of paraformaldehyde brings with it numerous safety issues including transportation, storage, handling, and environmental emissions. Formaldehyde exposure and emissions are closely monitored by both OSHA and the EPA. Paraformaldehyde hardener slurries are also burdened with a limited shelf life due to settling, such that they often need to be prepared just prior to use; this is often inconvenient and labor intensive. ANGUS oxazolidines are liquids which are stable, easy to handle, and contain less than 0.1% free formaldehyde. As a result, ANGUS oxazolidines are more attractive than paraformaldehyde from handling, exposure, and emission standpoints. Benefits of oxazolidine-based hardeners in PRF and RF resins include: Ease of handling (liquid; not dusty) Less than 0.1% free formaldehyde Lower formaldehyde emissions during cure (versus para) Adjustable cure response including oven, room temperature, and sub-ambient cure capabilities As discussed above, reactivity with a given PRF or RF resin is affected significantly by the choice of oxazolidine. The cure response of a given oxazolidine can be adjusted with the addition of strong bases, lower alcohols and glycols, and alkyhydroxylamines such as N-Isopropytheydroxylamine (IPHA). These materials will slow the reaction of oxazolidines with resin systems. Applications of oxazolidine hardeners with resorcinolcontaining resins include woodbonding adhesives, tire cord adhesives,refractory bricks and resorcinol modified starch adhesives. Phenolic Novolac Resins ANGUS oxazolidines can also be used as elevated temperature curing agents for phenolic novolac resins. Since the oxazolidines are liquids, they should first be adsorbed onto a solid carrier such as silica or wood flour, prior to mixing with the solid novolac. Reactivity can be adjusted by the choice of oxazolidine, as reviewed above. If necessary, cure speed can be increased by the addition of acids such as salicylic. Cure speed can be reduced through the addition of strong bases, etc., as discussed previously. ANGUS oxazolidines have advantages over the standard novolac curative, hexamethylenetetramine (Hexa). During cure, Hexa can generate significant amounts of ammonia, a concern in some applications such as molding compounds. ANGUS oxazolidines generate only minimal levels of ammonia during curing of novolacs. Another oxazolidine advantage (over Hexa) is that they are more easily incorporated into molding compounds, with the potential for shorter mixing times. Oxazolidine. Used as crosslinking and curing agent for urea- and melamine-formaldehyde, phenolic/resorcinol and phenolic novolac adhesive resins. Imparts great flexibility and elongation characteristics, and provides improved solvent resistance in urea- and melamine-formaldehyde based finished products. Applications with resorcinol containing resins: woodbonding adhesives, tire cord adhesives,and resorcinol modified starch adhesives.