Water Resistance

Addition of a crosslinker

While Nichigo G-Polymer™ is a resin with outstanding water solubility, water resistance can be achieved by using it with a crosslinker.
Nichigo G-Polymer™ also has high crosslinking performance compared to PVOH.

[Test conditions]
Preparation of a crosslinking test sample:

After adding Zircosol ZN (Daiichi Kigenso Kagaku Kogyo Co., Ltd.) as a crosslinker to each resin solution at a concentration of 10% at 10 phr/100 phr resin, the aqueous solution was air-dried at 23°C to form a film of about 100 μm.

Elution ratio measurement:
The elution ratio was measured after heat treatment of a test sample at each temperature for 5 minutes, and subsequent extraction with water at 80°C for 1 hour.

Nichigo G-Polymer™ : estimated DP: 1,200
Degree of saponification: 99.0 mol% or higher
PVOH : estimated DP: 1,200
Degree of saponification: 99.0 mol% or higher

[Evaluation of elution ratio]
After adding each crosslinker to aqueous solutions of 10% Nichigo G-Polymer™ concentration, adjust to the specified pH. Air-dry the aqueous solution at 23°C to create a film of approximately 100 μm. The resulting film was heat-treated and the elution ratio was measured when extracted with water at 80°C for 1 hour.

1): 10 phr/100 phr resin
* after pH adjustment
Changes in the mixed solution over time were observed by leaving the solution at room temperature.
Nichigo G-Polymer™ : estimated DP: 1,200
Degree of saponification: 99.0 mol% or higher