Water-soluble film, manufacturing method, and package

Patent metadata

Field	Value
Publication number	US-11939441-B2
Application number	US-202218036639-A
Country	US
Kind code	B2
Filing date	Sep 30, 2022
Priority date	Oct 1, 2021
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

The present disclosure relates to a water-soluble film with polyvinyl alcohol having a polymerization degree of 100 to 3,000 and a polyhydric alcohol plasticizer.

First claim

The invention claimed is:

1. A water-soluble film comprising polyvinyl alcohol having a polymerization degree of 100 to 3,000 and a polyhydric alcohol plasticizer in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol,
wherein in a case where the water-soluble film is used for a package in which a model detergent is packaged, the model detergent containing 8.6 mass % of monoethanolamine, 23.8 mass % of dodecylbenzenesulfonic acid, 9.5 mass % of propylene glycol, 23.8 mass % of a lauryl alcohol ethoxylate-7 ethylene oxide adduct, 19.1 mass % of oleic acid, 9.5 mass % of diethylene glycol, and 5.7 mass % of water, a weight reduction rate of the package when the package is stored at 23° C. and 50% RH is 1.0 to 6.0 g/(m 2 ·day) per surface area of the water-soluble film in contact with the model detergent of the package,
when the water-soluble film is immersed in the model detergent in an environment of 23° C. and 50% RH for 24 hours and then a tensile test is performed at 23° C. and 50% RH, an elastic modulus of the water-soluble film when the water-soluble film is stretched to 100% is 9 to 35 MPa, and
when the water-soluble film is immersed in the model detergent in an environment of 23° C. and 50% RH for 24 hours and then the water-soluble film is immersed in deionized water at 5° C., a complete dissolution time is within 100 seconds.

2. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol is carboxylic acid modified or sulfonic acid modified polyvinyl alcohol, and is polyvinyl alcohol having a saponification degree of 85 mol % or more.

3. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol has a polymerization degree of 500 to 1,500.

4. The water-soluble film according to claim 3 , wherein the polyvinyl alcohol has a saponification degree of 80 mol % to 99.5 mol %.

5. The water-soluble film according to claim 4 , wherein the polyvinyl alcohol has a saponification degree of 85 mol % to 97 mol %.

6. The water-soluble film according to claim 5 , comprising the polyhydric alcohol plasticizer in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol.

7. The water-soluble film according to claim 6 , wherein the polyhydric alcohol plasticizer is selected from ethylene glycol, glycerin, diglycerin, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane, and sorbitol.

8. The water-soluble film according to claim 6 , wherein the polyhydric alcohol plasticizer is glycerin.

9. The water-soluble film according to claim 6 , wherein the polyvinyl alcohol is unmodified polyvinyl alcohol.

10. The water-soluble film according to claim 6 , wherein the polyvinyl alcohol is sulfonic acid modified polyvinyl alcohol.

11. The water-soluble film according to claim 10 , wherein the sulfonic acid modified polyvinyl alcohol is polyvinyl alcohol modified with 2-acrylamido-2-methylpropyl sulfonic acid.

12. The water-soluble film according to claim 6 , wherein the polyvinyl alcohol is carboxylic acid modified polyvinyl alcohol.

13. The water-soluble film according to claim 12 , wherein the carboxylic acid modified polyvinyl alcohol is polyvinyl alcohol modified with monomethyl maleate.

14. The water-soluble film according to claim 1 , wherein a thickness of the water-soluble film is 5 to 80 μm.

15. A package comprising the water-soluble film according to claim 1 ,
wherein the package contains a chemical agent.

16. The package according to claim 15 , wherein the chemical agent is an agricultural chemical, a detergent, or a disinfectant.

17. The package according to claim 15 , wherein the chemical agent is a liquid form.

18. The package according to claim 17 , wherein the chemical agent is a detergent.

19. A method for manufacturing the water-soluble film according to claim 1 by casting a film forming stock solution containing polyvinyl alcohol into a film shape onto a support from a die through a die lip and drying the film forming stock solution,
wherein a draft ratio obtained by dividing a linear velocity of the support on which the film forming stock solution is cast by a linear velocity of the film forming stock solution at the die lip is 2 to 60, and
a draw ratio obtained by dividing a winding speed of the film after drying by the linear velocity of the support is 0.95 to 1.8.

20. The method for manufacturing the water-soluble film according to claim 19 , wherein the method includes a step of heat-treating the water-soluble film at 80 to 300° C.

Assignees

• Kuraray Co

Inventors

• Kazeto Osamu
• Takafuji Masahiro

Classifications

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08K5/053

  Polyhydroxylic alcohols · CPC title

• C08F16/06

  Polyvinyl alcohol {; Vinyl alcohol} · CPC title

• C08J2300/14

  Water soluble or water swellable polymers, e.g. aqueous gels · CPC title

• C08J2329/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title