ABSTRACT
The polyvinyl acetate (PVA) adhesives are most effectively used in simple high volume applications, and they are at a disadvantage only where evaporation of water is difficult, or where faster drying must be achieved. The most significant materials present in a PVA adhesive are polyvinyl acetate, stabilizers, plasticizers, and water. Copolymerization of vinyl acetate with other monomers prior to hydrolysis is possible, and various systems have been reported. It is claimed that Gohsefimer Z gives better water resistance than PVA emulsions stabilized with conventional polyvinyl alcohols. Where high water resistance is required, the polyvinyl alcohol can be crosslinked by means of glyoxal or by resins such as urea-formaldehyde or glyoxal-formaldehyde. Many PVA adhesives are polymerized using polyvinyl alcohol as the sole stabilizer. This produces a comparatively large particle size, which may be increased further by the introduction into the recipe of an oil-soluble initiator such as benzoyl peroxide.
