17 августа, 2015 
Malyar A PF resol is prepared and resorcinol is grafted onto it according to the schematic reaction shown in Formula 6.
The resin produced is capable of setting in 2 to 3 h and cures in 16 to 24 h at ambient temperature once paraformaldehyde and wood and nut flour fillers have been added. This is the most commercially used type of resorcinol cold-set adhesive, variations on the theme concerning mainly the hardener. Thus, sometime and especially in Europe, sludges formed by suspensions of organic or inorganic fillers in water mixed with liquid hardeners such as formalin and urea-formaldehyde precursor concentrates are used as hardeners for this type of adhesive. As these sludges and liquid hardeners have a bad formaldehyde odor during usage, hardeners based on odorless oxazolidines are often used instead of formaldehyde-based ones in these liquid or sludge hardeners.
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