Exceval RS-2617 Vinyl acetate Kuraray Polyvinyl acetate emulsions & derivatives (PVAc…) >> PVAc homopolymers ADHESIVE EXCEVAL is new water-soluble vinyl acetate resin and has a superior melt molding performance. A film form of "EXCEVAL" has high gas-barrier and water resistance properties. With these advantages, "EXCEVAL" can be used in various applications such as oxygen barrier material for food packaging, stabilizers for highly water-resistant adhesives, and raw material for melt-blown non-woven fabrics with hydrophile property. High water resistance : High crystallization performance of "EXCEVAL" provides its dry film with extremely high water resistance. Heat treatment brings better water resistance of the film. Viscosity stability of "EXCEVAL" aqueous solution : When "EXCEVAL" is used as aqueous solution, the viscosity stability is important for efficient process management. In case of conventional water soluble polymers, if the polymer has high water resistance, its aqueous solution tends to form gel during the storage at low temperature. " Surface tension of "EXCEVAL" aqueous solution : "EXCEVAL" aqueous solution has low surface tension and good surface activity. Therefore it can be used as a stabilizer for polyvinyl acetate emulsion. As the stabilizer, partially hydrolyzed polyvinyl alcohol (PVA) is generally used in the ordinary recipe. But when water resistance is required for the emulsion, partially hydrolyzed PVA is not suitable since the PVA does not have water resistance. For better water resistance, fully hydrolyzed PVA is desirable. But the surface tension of fully hydrolyzed PVA is high and it is difficult to obtain a stable polymerization for the emulsion. The low surface tension of "EXCEVAL" will provide both stable emulsion polymerization and better water resistance. Biodegradation : It is known that a water soluble resin, polyvinyl alcohol (PVA) can be biodegraded by the activated sludge treatment. "EXCEVAL"> is also biodegradable by the same treatment as PVA and KURARAY laboratory test shows that "EXCEVAL" has better biodegradability. Low moisture absorption : Dry film of "EXCEVAL" has low moisture absorption (equilibrium moisture content) and high young's modules. "EXCEVAL" is widely used as a stabilizer for the emulsion polymerization of vinyl acetate monomer(VAM)because of superior surface activity and superior protective colloidability of "EXCEVAL". PVAc Emulsion with using "EXCEVAL" provides superior stability in its viscosity at low temperature. The increasing of viscosity and gelation in winter can be prevented. High stability in viscosity of PVAc emulsion with "EXCEVAL" at low temperature can prevent PVAc emulsion from thicking viscosity and gelation in winter. Dry film of "EXCEVAL" has a remarkable higher water resistance than that with completely hydrolyzed polyvinyl alcohol. The surface activity of "EXCEVAL" is higher than that of the conventional completely hydrolyzed polyvinyl alcohol. Polymerization can be proceeded more stable. PVAc emulsion with "EXCEVAL" has the property of Newtonian flow (low structural viscosity index ) . PVAc emulsion with "EXCEVAL" has an excellent adhesion property for both wood and paper. Emulsion polymerization reactivity is so high that monomer consumption speed is faster than that of the conventional polyvinyl alcohol. Time to achieve the goal of residual monomer concentration can be shorter than that of the conventional polyvinyl alcohol. Water-soluble vinyl acetate resin. Used as a stabilizer for highly water-resistant adhesives. Possesses a high melt molding performance, viscosity stability, low surface tension and good surface activity, good biodegradability, low moisture absorption and high young's modules. Provides high gas-barrier and high water resistance properties. Offers a high protective colloidability, an excellent adhesion property for both wood and paper and high emulsion polymerization reactivity.