Method for sealing a water-soluble film by applying a sealing solution
AssigneeMonosol, LLC
InventorsSumeet Kumar, Percy Bromby, II, David M. Lee
Life of this patent
Estimating the term…
Abstract
Disclosed herein are sealing solutions for sealing water-soluble films, in particular aqueous mixtures including one or more polymeric solvents such as polyols. Aqueous sealing solutions including a relatively dilute solvent for one or more polymeric components of the water-soluble film (e.g., water-soluble polymeric components thereof, such as polyvinyl alcohol (PVOH)) can exhibit one or more benefits, including a reduction in dissolution of the film by the sealing solution and an increase in seal strength. Also disclosed are sealed articles formed with the sealing solutions, for example water-soluble packets containing various liquid or solid compositions.
Claims29
A method for sealing a water-soluble film, the method comprising:
- (a) applying a sealing solution to a first surface of a water-soluble film, the sealing solution comprising
- (i) water, and
- (ii) a polyol having 3 or more hydroxyl groups,
- wherein the sealing solution has a dynamic viscosity (μs) less than 1.5 cP as measured at 20° C.;
- and
- (b) contacting a second surface of a water-soluble film with the sealing solution on the first surface for a time sufficient to form a seal between the first surface and the second surface.
A method for scaling a water-soluble film, the method comprising:
- (a) applying a scaling solution to a first surface of a water-soluble film having an initial thickness less than about 50 μm and comprising a polyvinyl alcohol copolymer consisting essentially of vinyl alcohol monomeric repeat units and vinyl acetate monomeric repeat units, the scaling solution comprising
- (i) water, and
- (ii) a polyol present in the sealing solution in an amount ranging from about 2 wt. % to about 15 wt. %, the polyol being selected from the group consisting of glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fucitol, iditol, inositol, volemitol, isomalt, maltitol, lactitol, and combinations thereof.
- wherein the scaling solution has a dynamic viscosity (μs) less than 1.5 cP as measured al 20° C.;
- and
- (b) contacting a second surface of a water-soluble film having an initial thickness less than about 50 μm and comprising a polyvinyl alcohol copolymer consisting essentially of vinyl alcohol monomeric repeat units and vinyl acetate monomeric repeat units with the sealing solution on the first surface for a time sufficient to form a seal between the first surface and the second surface.
A method for sealing a water-soluble film, the method comprising:
- (a) applying a scaling solution to a first surface of a water-soluble film, the scaling solution comprising
- (i) water, and
- (ii) a solvent for at least one polymeric component of the water-soluble film,
- wherein
- (A) the solvent and the polymeric component have a solubility radius (Ra) of about 5 or less as defined by equation (I):
- (Ra)2=4(δDS−δD,P)2+(δP,X−δP,P)2 +(δH,S−δH,P)2 (I)
- where δDS is the solvent dispersive force, δD,P is the polymeric component dispersive force, δP,S is the solvent polar force, δP,P is the polymeric component polar force, δH,S is the solvent hydrogen bonding force, and δH,P is the polymeric component hydrogen bonding force, each of which is determined by a consistent method of Hansen solubility parameter evaluation, and
- (B) the sealing solution has a dynamic viscosity (μs) less than 1.5 cP as measured at 20° C.;
- and
- (b) contacting a second surface of a water-soluble film with the sealing solution on the first surface for a time sufficient to form a seal between the first surface and the second surface.
The method of claim wherein the solvent is present in the scaling solution in an amount ranging from about 2 wt. % to about 15 wt. %.
Dependencies are inferred from the claim text.