Water-soluble film, chemical agent package and water-soluble film production method

Patent metadata

Field	Value
Publication number	US-10696934-B2
Application number	US-201615753693-A
Country	US
Kind code	B2
Filing date	Sep 7, 2016
Priority date	Sep 11, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A water-soluble film contains a polyvinyl alcohol resin (A), and has a complete dissolution time (T) and a curl area percentage (S), wherein a product (T×S) of the complete dissolution time (T) and the curl area percentage (S) satisfies the following expression (1):

1000≤(Complete dissolution time ( T ))×(Curl area percentage ( S ))≤7000  (1)

The water-soluble film satisfies contradictory property requirements, i.e., satisfactory solubility and curl suppressing property, for example, even if being formed by using an acid-modified PVA resin.

First claim

The invention claimed is:

1. A water-soluble film comprising a polyvinyl alcohol resin (A), and having a complete dissolution time (T) and a curl area percentage (S), wherein a product (T×S) of the complete dissolution time (T) and the curl area percentage (S) satisfies the following expression (1):
1000≤(Complete dissolution time ( T ))×(Curl area percentage ( S ))≤7000  (1)

wherein the complete dissolution time (T) is a time (seconds) required for dissolving a 35 mm×35 mm specimen of the water-soluble film in water as measured when the specimen is immersed in water at 10° C. after being allowed to stand at 23° C. at 40% RH for 24 hours, and the curl area percentage (S) is a percentage (%) of an area of a curled portion of a 100 mm×100 mm specimen of the water-soluble film with respect to an area of the entire specimen as measured from its front side after the specimen is suspended at 23° C. at 40% RH for 24 hours with a machine direction (MD) edge of the specimen fixed;
wherein the polyvinyl alcohol resin (A) comprises a carboxyl-group-modified PVA resin;
wherein the water-soluble film further comprises a plasticizer (B) in a proportion of not less than 35 parts by weight based on 100 parts by weight of the PVA resin (A);
and wherein the water-soluble film is prepared by forming a film from a film-forming material containing the PVA resin (A), drying the film, and heat-treating the film at 95 to 135° C.

2. The water-soluble film according to claim 1 , wherein the complete dissolution time (T) is not longer than 150 seconds.

3. The water-soluble film according to claim 1 , wherein the curl area percentage (S) is not higher than 50%.

4. The water-soluble film according to claim 1 , wherein plasticizer (B) comprises plasticizer (b1) and plasticizer (b2), wherein the plasticizer (b1) is a polyalcohol having a melting point not lower than 80° C., and the plasticizer (b2) is a polyalcohol having a melting point not higher than 50° C.

5. The water-soluble film according to claim 4 , wherein the plasticizer (b1) is selected from the group consisting of salicyl alcohol, catechol, resorcinol, hydroquinone, bisphenol-A, bisphenol-F, neopentyl glycol, phloroglucinol, erythritol, threitol, pentaerythritol, xylitol, arabitol, fucitol, glucose, fructose, mannitol, sorbitol, inositol, lactitol, sucrose, maltitol, trehalose, and combinations thereof; and
wherein the plasticizer (b2) is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, tripropylene glycol, polyethylene glycol having a molecular weight of not greater than 2,000, glycerin, diglycerin, triethanolamine, and combinations thereof.

6. The water-soluble film according to claim 4 , wherein the plasticizer (B) is present in a proportion of [not less than 20] 35 to 70 parts by weight based on 100 parts by weight of the polyvinyl alcohol resin (A).

7. The water-soluble film according to claim 1 , wherein the water-soluble film has a water content of 3 to 15 wt. % as a whole.

8. The water-soluble film according to claim 1 , wherein the water-soluble film is usable for a chemical agent package.

9. A chemical agent package comprising:
a package bag formed from the water-soluble film according to claim 1 ; and
a liquid detergent packaged in the package bag.

10. The chemical agent package according to claim 9 ,
wherein the liquid detergent has a pH of 6 to 12 when dissolved or dispersed in water,
wherein the liquid detergent has a water content of not higher than 15 wt. %.

Assignees

• Nippon Synthetic Chem Ind Co Ltd
• Mitsubishi Chem Corp

Inventors

• Ookubo Masanori
• Katsuma Katsuhiko
• HIURA Takahiro

Classifications

• Y02W90/10

  Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics · CPC title

• B29B7/007 Primary

  for continuous mixing · CPC title

• B29B7/88

  Adding charges {, i.e. additives} · CPC title

• B29B7/726

  Measuring properties of mixture, e.g. temperature or density (B29B7/724 takes precedence) · CPC title

• C11D3/3753

  Polyvinylalcohol; Ethers or esters thereof · CPC title