Adhesives and Emulsions

The unique combination of properties in KURARAY POVAL™ grades has allowed for its widespread use in industrial adhesives. With more than 50 years of experience working with polyvinyl alcohol, Kuraray understands and continues to develop specialty and unique grades for the adhesives market. From ceramic binders to adhering to substrates like paper and wood, KURARAY POVAL™ improves tensile adhesive strength as a sole adhesive or as an additive.

PVOH (PVA) Product Finder

Find the right polyvinyl alcohol for your application here.

Optimised solutions for polymerization & adhesive processes

KURARAY POVAL™ is used for polyvinyl acetate emulsions, specifically in wood and paper adhesives. Kuraray’s specialty PVOH grades, like EXCEVAL™, are used for water-resistant wood adhesives. KURARAY POVAL™ can also be used in general-purpose adhesives such as textile, leather, wood, and porous ceramic surfaces.

The partially hydrolyzed grades of KURARAY POVAL™ are often selected for remoistening adhesives.

As an emulsifier, KURARAY POVAL™ and EXCEVAL™ are widely used as a protective colloid in the emulsion process. They are often used during the polymerization of vinyl acetate and vinyl acetate copolymer systems [vinyl acetate/ethylene, vinyl acetate/acrylic ester, etc.] to form high-solids emulsions with stability and adhesive properties. Kuraray PVOH products are also used in emulsions for non-vinyl acetate system [styrene/butadiene, styrene/acrylic ester, acrylic ester, etc.] lattices and bead or suspension polymerization of vinyl monomers like vinyl acetate, styrene, and vinyl chloride. KURARAY POVAL™ and EXCEVAL™ are also used during post-emulsification of hydrophobic substances like wax and asphalt.

EXCEVAL™ for Adhesives and Polymerization

Polyvinyl acetate emulsion (PVAc Em) was synthesized using Polyvinyl alcohol (PVOH) as a dispersant and mainly used in adhesive applications. The water resistance of a PVAc Emulsion is not high because PVOH is a water-soluble polymer (EN/DIN204 D2 level). Therefore, a crosslinking system is used in the application which requires high water resistance (EN/DIN204 D3 level). However, there is a risk that the typical system generates formaldehyde when the crosslinking reaction proceeds. From the standing point of health and the environment, high water-resistant adhesive with no formaldehyde generation is required and beneficial for consumers.

EXCEVAL™ has a hydrophobic functional group, and the film has high water resistance while keeping typical PVOH properties. PVAc Emulsion based on EXCEVAL™ shows high water resistance (D3 level) without using any crosslinking system which releases formaldehyde, and it is widely used in the application and regions where reduction of formaldehyde generation is required or even regulated.