Water-soluble film and package

Patent metadata

Field	Value
Publication number	US-12291613-B2
Application number	US-202117360055-A
Country	US
Kind code	B2
Filing date	Jun 28, 2021
Priority date	Dec 28, 2018
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

A water-soluble film is provided that is excellent in film transparency and water solubility and inhibits sticking between the films. A water-soluble film includes a polyvinyl alcohol resin, wherein a crystallite size obtained from an X-ray profile obtained by wide-angle X-ray measurement is from 4.0 to 5.5 nm and a degree of crystallization obtained from the X-ray profile is from 10.0% to 25.0%, and an external haze is from 7.0% to 30.0%.

First claim

The invention claimed is:

1. A water-soluble film comprising a polyvinyl alcohol resin, wherein
a crystallite size obtained from an X-ray profile obtained by wide-angle X-ray measurement is from 4.0 to 5.5 nm and a degree of crystallization obtained from the X-ray profile is from 10.0% to 25.0%, and
an external haze is from 7.0% to 30.0%, wherein the external haze is obtained by subtracting an internal haze from a total haze, in which the total haze is measured in accordance with ASTM D1003-61, and the internal haze is obtained by measuring haze of an adhesive-bonded water-soluble film in accordance with ASTM D1003-61.

2. The water-soluble film according to claim 1 , wherein the total haze is 55.0% or less.

3. The water-soluble film according to claim 2 , wherein the internal haze is 35.0% or less.

4. The water-soluble film according to claim 1 , further comprising a plasticizer, wherein
a content of the plasticizer is from 8 to 35 parts by mass based on 100 parts by mass of the polyvinyl alcohol resin.

5. A package comprising: the water-soluble film according to claim 1 and a chemical contained in the water-soluble film.

6. The package according to claim 5 , wherein the chemical is a pesticide, a detergent, or a germicide.

7. The package according to claim 5 , wherein the chemical is in a liquid form.

8. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol resin consists of an unmodified polyvinyl alcohol.

9. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol resin has a degree of polymerization of 500 to 3,000.

10. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol resin has a degree of saponification of 75 to 97 mol %.

11. The water-soluble film according to claim 1 , wherein the polyvinyl alcohol resin includes at least one selected from unmodified polyvinyl alcohol, an acrylamide-2-methylpropanesulfonic acid sodium salt (AMPS) modified polyvinyl alcohol, and a maleic acid monomethyl ester (MMM) modified polyvinyl alcohol.

12. The water-soluble film according to claim 1 , wherein the water-soluble film comprises a single polyvinyl alcohol resin or two or more polyvinyl alcohol resins having a degree of polymerization, a degree of saponification, and/or a degree of modification different from each other.

13. The water-soluble film according to claim 12 , wherein the water-soluble film comprises the single polyvinyl alcohol resin, and the single polyvinyl alcohol resin is a maleic acid monomethyl ester (MMM) modified polyvinyl alcohol.

14. The water-soluble film according to claim 12 , wherein the water-soluble film comprises the single polyvinyl alcohol resin, and the single polyvinyl alcohol resin is an acrylamide-2-methylpropanesulfonic acid sodium salt (AMPS) modified polyvinyl alcohol.

15. The water-soluble film according to claim 4 , wherein the plasticizer includes glycerin.

16. The water-soluble film according to claim 15 , further comprising lauric acid diethanolamide.

17. The water-soluble film according to claim 1 , wherein the water-soluble film is formed by a process that includes discharging a stock solution including the polyvinyl alcohol resin on a drying roll having a surface temperature of 65° C. to 80° C.

18. The water-soluble film according to claim 17 , wherein the process further includes blowing air at a temperature of 70° C. to 120° C. and at a wind velocity of 1 to 10 m/second during the discharging.

19. The water-soluble film according to claim 17 , wherein the process further includes, before the discharging, filtering the stock solution.

20. The water-soluble film according to claim 19 , wherein the stock solution is filtered by two metal screen mesh filters.

Assignees

• Kuraray Co

Inventors

• Okamoto Minoru
• Shimizu Sayaka
• Kazeto Osamu
• Asada Mitsunori

Classifications

• C08K5/053

  Polyhydroxylic alcohols · CPC title

• C08J2329/04

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

• B65D65/46

  Applications of disintegrable, dissolvable or edible materials · CPC title

• C11D17/042

  Water soluble or water disintegrable containers or substrates containing cleaning compositions or additives for cleaning compositions · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title