	US 12,071,524 B2
	Water-soluble film and packaging material
Minoru Okamoto, Okayama (JP); Sayaka Shimizu, Okayama (JP); Osamu Kazeto, Okayama (JP); and Mitsunori Asada, Okayama (JP)
Assigned to KURARAY CO., LTD., Okayama (JP)
Filed by KURARAY CO., LTD., Okayama (JP)
Filed on Jun. 28, 2021, as Appl. No. 17/360,040.
Application 17/360,040 is a continuation of application No. PCT/JP2019/051491, filed on Dec. 27, 2019.
Claims priority of application No. 2018-248290 (JP), filed on Dec. 28, 2018.
Prior Publication US 2021/0324161 A1, Oct. 21, 2021 Prior Publication US 2024/0254294 A9, Aug. 1, 2024
Int. Cl. C08J 5/18 (2006.01); C08L 29/04 (2006.01)

CPC C08J 5/18 (2013.01) [C08J 2329/04 (2013.01)]

19 Claims

1. A water-soluble film comprising at least one polyvinyl alcohol-based resin, wherein

the water-soluble film has a crystal long period Ds from 10.0 to 30.0 nm as obtained from an X-ray profile obtained by small-angle X-ray scattering measurement of the water-soluble film after immersion in a water/methanol mixed solvent at a volume ratio: 2/8, and

a rate of increase (Ds−Da)/Da of the crystal long period Ds to a crystal long period Da obtained by the small-angle X-ray scattering measurement before the immersion in the mixed solvent is 30% or more and 130% or less.

15. The water-soluble film according to claim 1, wherein the water-soluble film is formed from a film forming stock solution having volatile components at a concentration of 55 to 80 mass %.

16. The water-soluble film according to claim 15, wherein the water-soluble film is formed by casting the film forming stock solution on a support having a surface temperature of 65° C. to 95° C.