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.
    
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

Due to the high water resistance of EXCEVAL™, polyvinyl acetate emulsions using EXCEVAL™ can achieve D3 performance level without using crosslinking technology. If an even higher water resistance performance is needed, it can be achieved simply by using standard crosslinking technology.


PROPERTIES

  • Outstanding film strength
  • Strong binding capacity
  • Resistant to oils, greases, and waxes
  • Can be combined with extenders like clays and insolubizers
  • Cold-water insolubility
  • Medium viscosity tackified PVOH for use in adhesives of cellulosic substrates
  • Fast bonding speed
  • Ability to form high solids in emulsions
  • Controls particle size and distribution in emulsions
  • Works as a viscosity builder in emulsions

APPLICATIONS

  • Manufacturing of solid fiberboard, spiral-wound tubes, cores, and drums
  • Paper laminating adhesives
  • Water-resistant adhesives
  • Emulsions of vinyl acetate and vinyl acetate ethylene
  • Nonionic emulsifiers and protective colloids in the preparation of oil-water emulsions and dispersions (wax etc.)
  • Adhesion enhancer for amino resins (UF, MUF, etc.)
  • EPI (Emulsion-Polymer-Isocyanate) adhesives