| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a binder for an ink or coating film capable of obtaining the ink and coating material excellent in storage stability and having high glossiness of coating film formed by applying obtained ink or coating material.SOLUTION: There is provided a binder for ink or coating material containing polyvinyl acetal having an acetalization degree of 50 to 85 mol%, the content of vinyl ester monomer unit of 0.1 to 20 mol% and viscosity average polymerization degree of 200 to 1000, having a peak top molecular weight measured by a differential refractive index detector (A) and a peak top molecular weight measured by an absorbancy detector (measurement wavelength 280 nm) (B) when the polyvinyl acetal heated at 230°C for 3 hours is subjected to a gel permeation chromatography measurement satisfying following formula (1), (A-B)/A<0.50 (1) and absorbancy at the peak top molecular weight (B) is 0.50×10to 1.00×10.</p> |
