KURARAY POVAL™ is the brand name of Kuraray’s globally produced polyvinyl alcohol (PVOH).
KURARAY POVAL™ features an extremely wide-ranging field of applications. The main uses are in the paper, adhesive, textile and construction industries, as well as in ceramics, packaging and electronics. The physical and chemical properties make PVOH very versatile. It features water-solubility, excellent film forming characteristics, high tensile strength and elasticity, as well as resistance against organic solvents and dispersing power.
ELVANOL™ is a recent addition to Kuraray’s polyvinyl alcohol product portfolio. Its unique particle morphology, coming from a special production process expands its range of applications. ELVANOL™ can be dissolved in the continuous cooking process designed for starch in which standard polyvinyl alcohols remain undissolved. This will be a significant benefit in paper coating applications, especially where polyvinyl alcohols are used together with starch to enhance performance.
KURARAY POVAL™ and ELVANOL™ dissolve in water. The higher the water temperature, the quicker the rate of dissolution. These products have extremely high oil resistance, and are insoluble in most organic solvents. However, they dissolve in certain organic solvents such as glycols, DMSO and phenol.
These materials are mostly unaffected under weak acid or alkaline conditions.
The melting point and temperature at which KURARAY POVAL™ and ELVANOL™ start thermal decomposition are close together, with gradual decomposition at 180ºC or higher.
Easily converted to threads or films, and the physical properties, including tensile strength, tear strength and abrasion strength, are excellent compared with other synthetic resins
Lower hygroscopicity than other water-soluble polymers, and any changes caused by varying humidity are relatively minor
KURARAY POVAL™ standard grades
|Type||Grade||Volatile matter %||Sodium acetate %||Hydrolysis mol%||Viscosity (4%, 20ºC) mPa·s||Purity %|
|Fully hydrolyzed||3-98||5.0 or lower||1.5 or lower||98.0～99.0||3.2～3.8||94.0 or higher|
|5-98||5.0 or lower||1.5 or lower||98.0～99.0||5.2～6.0||94.0 or higher|
|28-98||5.0 or lower||1.0 or lower||98.0～99.0||25.0～31.0||94.0 or higher|
|60-98||5.0 or lower||1.0 or lower||98.0～99.0||54.0～66.0||94.0 or higher|
|Medium hydrolyzed||27-96||5.0 or lower||1.0 or lower||95.5～96.5||24.0～30.0||94.0 or higher|
(Degree of hydrolysis: 88)
|3-88||5.0 or lower||1.0 or lower||87.0～89.0||3.2～3.6||94.0 or higher|
|5-88||5.0 or lower||1.0 or lower||86.5～89.0||4.6～5.4||94.0 or higher|
|22-88||5.0 or lower||1.0 or lower||87.0～89.0||20.5～24.5||94.0 or higher|
|44-88||5.0 or lower||1.0 or lower||87.0～89.0||40.0～48.0||94.0 or higher|
|95-88||5.0 or lower||1.0 or lower||87.0～89.0||80.0～110.0||94.0 or higher|
(Degree of hydrolysis: 80)
|48-80||5.0 or lower||0.5 or lower||78.5～80.5||45.0～51.0||―|
|L-10||5.0 or lower||―||71.5～73.5||5.0～7.0||96.0 or higher|
KURARAY POVAL™ modified grades
|K series||Characterized by high water solubility and reactivity. It has a wide range of applications, including as a paper processing agent, adhesive and water-soluble film.||25-88KL|
|SD series||Characterized by low viscosity and high solubility. It is used as a dispersing agent for thermal paper.||3-86SD|
|LM series||Characterized by low hydrolysis and high surface activity. It is used as a secondary dispersing agent for PVC polymerization.||LM-20
|KX series||Characterized by extremely high viscosity. It is used as a stabilizer for emulsions, adhesives and warp sizing agents.||105-88KX
Visit the KURARAY POVAL™ homepage for more information and other grades.
|Type||Grade||Volatile matter %||Ash content %||Hydrolysis mol%||Viscosity (4%, 20 ºC) mPa·s||pH|
|ELVANOL™||71-30||5.0 or lower||0.7% or lower||99.5||27.0 - 33.0||5.0 - 7.0|
|90-50||5.0 or lower||0.7% or lower||99.5||11.6 - 15.4||5.0 - 7.0|
|T-25||5.0 or lower||0.7% or lower||99.5||24.0 - 32.0||5.0 - 7.0|
|T-66||5.0 or lower||0.7% or lower||99.5||11.6 - 15.4||5.0 - 7.0|