Products

Product index | Support

Exceval™

Description

Exceval™ is the trademark of Kuraray's novel water soluble polymer, specially designed for “high water resistance”. It is commonly known that fully hydrolyzed polyvinyl alcohol shows higher water resistance based on the higher crystallinity than that of partially hydrolyzed polyvinyl alcohol, but “viscosity stability” is the critical problem. ExcevalTM achieves the compatibility of both performances, “high water resistance” and “viscosity stability” based on Kuraray's accumulated technology.

Exceval Grade List

Download PDF version

	Grade	Viscosity¹DIN 53015 [mPa x s]	Degree of hydrolysis (saponification) [mol.-%]	Max Ash content²[%]	Max Volatile content³[%]

Super hydrolyzed grades	HR-3010	12.0-16.0	99.0-99.4	0.4	5.0
Fully hydrolyzed grades	RS-2117	23.0-30.0	97.5-99.0	0.4	5.0
Fully hydrolyzed grades	AQ-4104	3.5- 4.5	98.0-99.0	0.4	5.0
Medium hydrolyzed grades	RS-1717	23.0-30.0	92.0-94.0	0.4	5.0

¹ of a 4% aqueous solution at 20º C determined by Brookfield synchronized rotary-type viscometer.
² calculated as Na2O.
³ after 3 hours' drying time at 105º C. Methanol content less than 3%.

Applications

• Wood adhesives
• Packaging adhesives
• Top coat for thermal-sensitive paper
• Release paper
• Gas barrier coating

Exceval™ for polyvinyl acetate emulsion adhesives

	Protective colloid	Crosslinker	Adhesive Property
			D2	D3
			*2 >8N/mm²	*3 >2N/mm²	*4 >8N/mm²

1	HR-3010 [10phm]	none	14.6	3	13.6
2	RS-2117	none	13.9	2.9	13.6
3	D3-Em	AlCl3	14.2	2.5	13.3

Adhesive property ; Measured based on British Standard
*2 : 3 hours in cold water, 7 days at 65%RH and 20ºC (68ºF)
*3 : 4 days in cold water at 20ºC (68ºF) samples tested wet
*4 : 4 days in cold water, 7 days at 65%RH and 20ºC (68ºF)
D3-Em; commmercially available D3-Emulsion

Exceval™ for gas barrier coatings

Partially hydrolyzed polyvinyl alcohol is commonly used as a protective colloid in polyvinyl acetate emulsion adhesives. Partially hydrolyzed polyvinyl alcohol is well water soluble so to get high water resistance adhesive, cross-linking is needed.

Exceval™ can be used as a protective colloid and obtained emulsion shows excellent water resistance without any cross-linker because of the high water resistance of Exceval™.

Polyvinyl alcohol is well known gas barrier coatings can be processed by aqueous solution. But the applications have been limited into dry material packaging because the performance gets worse in high humidity condition. Exceval™ shows higher gas barrier at elevated humidity because of the less sensitivity to water.

Documentation

Top