Polyvinyl alcohol used as dispersing agents for polyvinyl chloride suspension polymerization, dispersing agents comprising the polyvinyl alcohol, and method for producing polyvinyl chloride using the polyvinyl alcohol

Abstract

The polyvinyl alcohol according to the present invention to be used as a dispersant for suspension polymerization for polyvinyl chloride has a degree of saponification of 60 to 80 mol %, a block character of 0.4 to 0.6, an integration value defined by the following (a) of 0.04 to 0.1 and an integration value defined by the following (b) of 0.01 to 0.2 in a 1H-NMR spectrum, and a 0.1% by mass aqueous solution of the polyvinyl alcohol has a UV absorbance at a wavelength of 320 nm of 0.18 or more and less than 0.3. (a) An integration value from 5.42 to 5.62 ppm of a peak or peaks observed at 5.50 to 5.54 ppm when an integration value from 3.65 to 4.05 ppm of a peak or peaks observed at 3.83 to 3.87 ppm is assumed to be 100. (b) An integration value from 5.76 to 5.98 ppm of a peak or peaks observed at 5.86 to 5.90 ppm when an integration value from 3.65 to 4.05 ppm of a peak or peaks observed at 3.83 to 3.87 ppm is assumed to be 100.

Dependencies are inferred from the claim text.