Packaging bag, and method using same for storing polyvinyl alcohol-based resin that contains modified group having active hydrogen
A packaging bag for packaging a polyvinyl alcohol-based resin that contains a modified group having active hydrogen, the packaging bag including a film having a water vapor permeability of 10 g/m 2 /day or less. Accordingly, when a polyvinyl alcohol-based resin that contains a modified group having active hydrogen is packaged with the packaging bag, the storage stability of the polyvinyl alcohol-based resin that contains a modified group having active hydrogen can be improved, and hence an aqueous solution of the polyvinyl alcohol-based resin that contains a modified group having active hydrogen, the solution being reduced in insoluble matter content, can be obtained even after long-term storage thereof.
1. A method comprising packaging a polyvinyl alcohol-based resin that contains a modified group having active hydrogen within a packaging bag;
wherein the packaging bag comprises a film containing a low-density polyethylene and having a water vapor permeability of 10 g/m 2 /day or less; and
wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen comprises a powdery matter having an average particle diameter of from 100 μm to 1,000 μm.
2. The method according to claim 1 , wherein the packaging bag includes only a water vapor barrier layer having a water vapor permeability of 10 g/m 2 /day or less.
3. The method according to claim 1 , wherein the packaging bag includes a multilayer structure film formed of a substrate film layer, a water vapor barrier layer, and a protective film layer.
4. The method according to claim 1 , wherein the packaging bag has a thickness of from 10 μm to 450 μm.
5. The method according to claim 1 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen has an average polymerization degree in conformity with JIS K 6726 of from 200 to 4,000.
6. The method according to claim 1 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen has a saponification degree in conformity with JIS K 6726 of from 80 mol % to 100 mol %.
7. The method according to claim 1 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen comprises an acetoacetyl group-containing polyvinyl alcohol-based resin.
8. The method according to claim 1 , wherein the packaging bag further comprises kraft paper, the kraft paper being outside the film.
9. The method according to claim 1 , wherein the packaging bag is sheathed with a sheath bag comprising kraft paper.
10. A method of storing a polyvinyl alcohol-based resin that contains a modified group having active hydrogen, wherein the method comprises hermetically sealing a powdery matter of the polyvinyl alcohol-based resin that contains a modified group having active hydrogen with a packaging bag including a film containing a low-density polyethylene having a water vapor permeability of 10 g/m 2 /day or less; and
wherein the powdery matter of the polyvinyl alcohol-based resin that contains a modified group having active hydrogen has an average particle diameter of from 100 μm to 1,000 μm.
11. The method according to claim 10 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen comprises an acetoacetyl group-containing polyvinyl alcohol-based resin.
12. The method according to claim 10 , wherein the packaging bag includes only a water vapor barrier layer having a water vapor permeability of 10 g/m 2 /day or less.
13. The method according to claim 10 , wherein the packaging bag includes a multilayer structure film formed of a substrate film layer, a water vapor barrier layer, and a protective film layer.
14. The method according to claim 10 , wherein the packaging bag has a thickness of from 10 μm to 450 μm.
15. The method according to claim 10 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen has an average polymerization degree in conformity with JIS K 6726 of from 200 to 4,000.
16. The method according to claim 10 , wherein the polyvinyl alcohol-based resin that contains a modified group having active hydrogen has a saponification degree in conformity with JIS K 6726 of from 80 mol % to 100 mol %.
17. The method according to claim 10 , wherein the packaging bag further comprises kraft paper, the kraft paper being outside the film.
18. The method according to claim 10 , wherein the packaging bag is sheathed with a sheath bag comprising kraft paper.