US 12,227,607 B2
Production method for modified vinyl alcohol-based polymer particles and particles obtained using same
Yuki Tachibana, Kurashiki (JP); Yusuke Amano, Kurashiki (JP); Yuki Shimizu, Kurashiki (JP); and Kazuhiko Maekawa, Kurashiki (JP)
Assigned to KURARAY CO., LTD., Kurashiki (JP)
Appl. No. 17/438,697
Filed by KURARAY CO., LTD., Kurashiki (JP)
PCT Filed Mar. 12, 2020, PCT No. PCT/JP2020/010775
§ 371(c)(1), (2) Date Sep. 13, 2021,
PCT Pub. No. WO2020/184659, PCT Pub. Date Sep. 17, 2020.
Claims priority of application No. 2019-047539 (JP), filed on Mar. 14, 2019.
Prior Publication US 2022/0144977 A1, May 12, 2022
Int. Cl. C08F 8/14 (2006.01); B29B 9/12 (2006.01); C08F 16/06 (2006.01); B29K 29/00 (2006.01)
CPC C08F 8/14 (2013.01) [B29B 9/12 (2013.01); C08F 16/06 (2013.01); B29K 2029/04 (2013.01)] 13 Claims
 
1. A method of producing modified vinyl alcohol-based polymer particles, the method comprising:
mixing vinyl alcohol-based polymer particles with a mixed medium comprising unsaturated carboxylic acid, an acid catalyst, and water, thereby reacting the vinyl alcohol-based polymer particles with the unsaturated carboxylic acid to obtain modified vinyl alcohol-based polymer particles comprising a vinyl ester unit, having a vinyl alcohol unit content based on the total constitutional units from 95 to 99.99 mol %, and having an average particle diameter from 50 to 2000 μm,
wherein the unsaturated carboxylic acid is a compound of formula (1):

OG Complex Work Unit Chemistry
X denotes a carbon-carbon bond or a divalent saturated hydrocarbon group having a carbon number from 1 to 10 optionally having a branched structure, Y denotes a hydrogen atom or a saturated hydrocarbon group having a carbon number from 1 to 6 optionally having a branched structure, and Z denotes a hydrogen atom or a methyl group, and
the vinyl ester unit is a unit of formula (2):

OG Complex Work Unit Chemistry