Modified vinyl alcohol copolymer, resin film and water-soluble packaging

Abstract

A modified polyvinyl alcohol copolymer has a degree of saponification of 70 mole % or more according to JIS K 6726 (1994) standard, comprising monomer units containing carboxyl groups and monomer units containing lactam functional groups; wherein when a 1H-NMR spectrum of the copolymer is measured at 400 MHz and 25° C. using DMSO-d6 as solvent, an integrated area of the spectrum from 3.65 to 4.00 ppm is defined as 1 and the integrated area from 2.05 to 2.35 ppm in the spectrum is 0.002 to 0.200; wherein when the copolymer is subjected to thermal analysis using a differential scanning calorimeter, in the curve with temperature as X-axis and heat flow as Y-axis, the slope between 100° C. and melting point Tm (° C.) is between −0.00100 and −0.00190 W/g° C. The copolymer is applicable for preparing polyvinyl alcohol water-soluble films. The present disclosure also relates to a resin film and water-soluble package.

Dependencies are inferred from the claim text.