Articles Comprising Water-Soluble Polyvinyl Alcohol Film with Plasticizer Blend and Related Methods

Abstract

Disclosed herein are articles that include water-soluble films, where the water-soluble films include a polyvinyl alcohol (PVOH) polymer and a combination of at least three plasticizers. The combination of plasticizers includes dipropylene glycol as a first plasticizer, a sugar alcohol such as sorbitol as a second plasticizer, and a polyol such as glycerin as a third plasticizer. When the PVOH polymer and plasticizers are blended in particular proportions and/or selected with regard to various criteria related to physical and chemical film properties, the resulting water-soluble film formed from the PVOH resin blend exhibits beneficial combinations of aged tensile strength, aged melting transition delta elevation, aged adhesion value, and/or resistance to seal peeling, which provide strong film seals that retain their water-solubility characteristics.

1 . An article comprising:
 a. a water-soluble film, wherein the water-soluble film comprises:
 a polyvinyl alcohol (PVOH) polymer, the PVOH polymer comprising a PVOH homopolymer that includes vinyl alcohol monomer units and optionally vinyl acetate monomer units; 
 dipropylene glycol as a first plasticizer; 
 a sugar alcohol as a second plasticizer, wherein the sugar alcohol is selected from the group consisting of isomalt, maltitol, sorbitol, xylitol, erythritol, adonitol, dulcitol, pentaerythritol, and mannitol; and 
 a polyol as a third plasticizer, the third plasticizer being selected from the group consisting of glycerin, diglycerin, ethylene glycol, diethylene glycol, triethyleneglycol, tetraethylene glycol, polyethylene glycols up to 400 MW, neopentyl glycol, propylene glycol, 2-methyl-1,3-propanediol, trimethylolpropane, and polyether polyols; and 
   b. a household care composition.   
     
     
         2 . (canceled) 
     
     
         3 . The article of  claim 1 , wherein the sugar alcohol is sorbitol. 
     
     
         4 . (canceled) 
     
     
         5 . The article of  claim 1 , wherein the polyol is glycerin. 
     
     
         6 . The article of  claim 1 , wherein the water-soluble film comprises:
 the polyvinyl alcohol (PVOH) polymer;   dipropylene glycol as the first plasticizer;   sorbitol as the second plasticizer; and   glycerin as the third plasticizer;   wherein the first, second, and third plasticizers are present in the water-soluble film in a combined amount in a range of about 5 parts to about 50 parts total plasticizer per 100 parts total resin (phr) in the water-soluble film.   
     
     
         7 . The article of  claim 1 , wherein the first, second, and third plasticizers are present in the water-soluble film in a combined amount in a range of about 5 parts to about 40 parts total plasticizer per 100 parts total resin (phr) in the water-soluble film. 
     
     
         8 . The article of  claim 1 , wherein:
 the water-soluble film has an aged tensile strength of at least about 25 MPa as measured by the Aged Tensile Strength Test; and   the water-soluble film has a seal tear value of at least about 170% as measured by the Sum Seal Tear Test.   
     
     
         9 . The article of  claim 1 , wherein:
 the first plasticizer is present in the water-soluble film in an amount in a range of about 10 wt. % to about 40 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film;   the second plasticizer is present in the water-soluble film in an amount in a range of about 10 wt. % to about 30 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film; and   the third plasticizer is present in the water-soluble film in an amount in a range of about 40 wt. % to about 70 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         10 . The article of  claim 1 , wherein:
 the first plasticizer is present in the water-soluble film in an amount in a range of about 10 wt. % to about 65 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         11 . The article of  claim 1 , wherein:
 the second plasticizer is present in the water-soluble film in an amount in a range of about 10 wt. % to about 65 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         12 . The article of  claim 1 , wherein:
 the third plasticizer is present in the water-soluble film in an amount in a range of about 25 wt. % to about 80 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         13 . The article of  claim 1 , wherein:
 the first plasticizer is present in the water-soluble film in an amount in a range of about 13 wt. % to about 58 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film;   the second plasticizer is present in the water-soluble film in an amount in a range of about 13 wt. % to about 58 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film; and   the third plasticizer is present in the water-soluble film in an amount in a range of about 28 wt. % to about 73 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         14 . The article of  claim 1 , wherein:
 the first plasticizer is present in the water-soluble film in an amount in a range of about 13 wt. % to about 19 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film;   the second plasticizer is present in the water-soluble film in an amount in a range of about 41 wt. % to about 52 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film; and   the third plasticizer is present in the water-soluble film in an amount in a range of about 35 wt. % to about 44 wt. % relative to the combined amount of the first, second, and third plasticizers in the water-soluble film.   
     
     
         15 . The article of  claim 1 , wherein the water-soluble film has at least two of the three properties (a), (b), and (c):
 (a) an aged melting transition delta elevation of about 12° C. or less as measured by the Aged Melting Transition Delta Test;   (b) an aged adhesion value of at least about 1300 g/s as measured by the Aged Adhesion Test; and   (c) an aged tensile strength of at least about 25 MPa as measured by the Aged Tensile Strength Test.   
     
     
         16 . The article of  claim 1 , wherein the water-soluble film further comprises one or more components selected from the group consisting of plasticizers other than the first, second, and third plasticizers, plasticizer compatibilizers, lubricants, release agents, fillers, extenders, cross-linking agents, antiblocking agents, antioxidants, detackifying agents, antifoams, nanoparticles, bleaching agents, surfactants, and combinations thereof. 
     
     
         17 . The article of  claim 1 , wherein the PVOH polymer further comprises a PVOH copolymer comprising an anionic monomer unit, a vinyl alcohol monomer unit, and optionally a vinyl acetate monomer unit. 
     
     
         18 . The article of  claim 17 , wherein the anionic monomer is selected from the group consisting of vinyl acetic acid, maleic acid, monoalkyl maleate, dialkyl maleate, monomethyl maleate, dimethyl maleate, maleic anyhydride, fumaric acid, monoalkyl fumarate, dialkyl fumarate, monomethyl fumarate, dimethyl fumarate, fumaric anyhydride, itaconic acid, monomethyl itaconate, dimethyl itaconate, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, ethylene sulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methylacrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, alkali metal salts of the foregoing, esters of the foregoing, and combinations thereof. 
     
     
         19 . The article of  claim 1 , wherein the PVOH polymer comprises a polymer blend comprising two or more different PVOH homopolymers. 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . The article of  claim 1 , wherein the article is in the form of a pouch comprising at least one sealed compartment. 
     
     
         23 . The article of  claim 22 , wherein the at least one compartment comprises at least one wall, wherein the at least one wall comprises the water-soluble film. 
     
     
         24 . The article of  claim 22 , wherein the pouch comprises at least two compartments. 
     
     
         25 . The article of  claim 24 , wherein a second compartment is superposed on a first compartment. 
     
     
         26 . The article of  claim 24 , wherein the pouch comprises at least three compartments. 
     
     
         27 . The article of  claim 22 , wherein the household care composition is contained in the at least one compartment. 
     
     
         28 . The article of  claim 1 , wherein the household care composition is selected from the group consisting of light duty liquid detergents compositions, heavy duty liquid detergent compositions, hard surface cleaning compositions, detergent gels commonly used for laundry, bleaching compositions, laundry additives, fabric enhancer compositions, shampoos, body washes, other personal care compositions, and mixtures thereof. 
     
     
         29 . The article of  claim 1 , wherein the household care composition comprises surfactant. 
     
     
         30 . The article of  claim 1 , wherein the household care composition is in the form of a liquid, solid, a powder, or mixtures thereof. 
     
     
         31 . The article of  claim 1 , wherein the household care composition is in contact with the water-soluble film. 
     
     
         32 . A method of forming the article of  claim 1 , wherein the method comprises the steps of:
 providing the water-soluble film, wherein the film defines an interior pouch container volume;   filling the container volume with a household care composition; and   sealing the film to form a sealed compartment, wherein the sealed compartment contains the composition.   
     
     
         33 . A method of treating a substrate, wherein the method comprises the step of contacting the substrate with the article of  claim 1 . 
     
     
         34 . The article of  claim 19 , wherein the polymer blend comprises a first partially hydrolyzed PVOH homopolymer and a second partially hydrolyzed PVOH homopolymer in about a 50 wt. %/50 wt. % ratio. 
     
     
         35 . The article of  claim 1 , wherein the PVOH polymer comprises a first partially hydrolyzed PVOH homopolymer that is characterized by a 4% solution viscosity of about 13 cP. 
     
     
         36 . The article of  claim 1 , wherein the PVOH polymer comprises a second partially hydrolyzed PVOH homopolymer that is characterized by a 4% solution viscosity of about 23 cP.