Water-soluble unit dose article comprising a water-soluble film comprising a polyvinyl alcohol polymer comprising an anionic monomer unit

1. A multicompartment water-soluble unit dose article comprising a treatment composition and comprising at least a first water-soluble film, a second water-soluble film, a third water-soluble film, and a fourth water-soluble film,

wherein the first water-soluble film, the second water-soluble film, the third water-soluble film, and the fourth water-soluble film each comprises a polyvinyl alcohol polymer system,

wherein the polyvinyl alcohol polymer systems of the first, second, third, and fourth water-soluble films are the same as one another,

wherein each of the polyvinyl alcohol polymer systems comprises

(a) a polyvinyl alcohol/monocarboxylate copolymer, or

(b) a 60/40-70/30 blend of a polyvinyl alcohol homopolymer and a polyvinyl alcohol-maleate copolymer,

wherein the polyvinyl alcohol homopolymer and the polyvinyl alcohol-maleate copolymer are present in the blend in a weight ratio of from 60/40 to 70/30; and

wherein the multicompartment water-soluble unit dose article comprises at least one seal region in which the at least first water-soluble film, the second water-soluble film, the third water-soluble film, and the fourth water-soluble films are sealed together, and wherein the water-soluble films define at least two internal compartments, wherein one internal compartment is positioned above the other internal compartment in a superposed orientation, and the two internal compartments are separated from one another by at least two water-soluble films.

2. The water-soluble unit dose article according to claim 1 , wherein the monocarboxylate or maleate is present in the copolymer (a) and blend (b), respectively, in an average amount in a range of between about 1 mol. % and about 10 mol. %.

3. The water-soluble unit dose article according to claim 1 , wherein the copolymer (a) or the blend (b) has an average viscosity (μl) in a range of between about 4 mPa·s and about 30 mPa·s, measured as a 4% solution in demineralized water at about 20° C.

4. The water-soluble unit dose article according to claim 1 , wherein the copolymer (a) or the blend (b) has an average degree of hydrolysis in a range of between about 75% and about 99%.

5. The water-soluble unit dose article according to claim 1 , wherein the total amount of any polyvinyl alcohol polymer system present in any individual film is between about 30% and about 95% by weight of that individual film.

6. The water-soluble unit dose article according to claim 1 , wherein the first water-soluble film, the second water-soluble film, the third water-soluble film, and the fourth water-soluble film each comprise the copolymer (a) that are the same as one another.

7. The water-soluble unit dose article according to claim 1 , wherein the first water-soluble film, the second water-soluble film, the third water-soluble film, and the fourth water-soluble film each comprise the blend (b) that are the same as one another.

8. The water-soluble unit dose article according to claim 1 , wherein the first water-soluble film and the second water-soluble film are configured to form at least one internal compartment, and wherein the third water-soluble film and fourth water-soluble film are configured to form at least one internal compartment, and wherein the at least one internal compartment formed by the third water-soluble and fourth water-soluble film is superposed onto the at least one compartment formed by the first water-soluble film and the second water-soluble film, and wherein the second water-soluble film and the third water-soluble film are in direct contact with one another.

9. The water-soluble unit dose article according to claim 1 , wherein the water-soluble unit dose article comprises at least three internal compartments.

10. The water-soluble unit dose article according to claim 1 , wherein the third water-soluble film and the fourth water-soluble film are configured to form at least two internal compartments arranged in a side-by-side configuration.

11. The water-soluble unit dose article according to claim 1 , wherein the films are sealed together via solvent sealing, heat sealing, or a mixture thereof.

12. The water-soluble unit dose article according to claim 1 , wherein the seal region comprises a flange region, and wherein the first water-soluble film, the second water-soluble film, the third water-soluble film and the fourth water-soluble films are at least partially sealed together in the flange region.

13. The water-soluble unit dose article according to claim 1 , wherein at least one internal compartment comprises a treatment composition selected from a laundry treatment composition, dishwashing composition, hard surface treatment composition, or a mixture thereof.

14. A process for making a water-soluble unit dose article according to claim 1 comprising the steps of:

a. deforming the first water-soluble film into a cavity to make at least one open compartment;

b. filling the at least one open compartment from step a with a treatment composition;

c. closing the at least one open compartment from step b with the second water-soluble film;

d. sealing the first water-soluble film and the second water-soluble film together to make an at least first closed intermediate article;

e. deforming the fourth water-soluble film into a cavity to create at least one open compartment;

f. filling the at least one open compartment from step e with a treatment composition;

g. closing the at least one open compartment from step f with the third water-soluble film;

h. sealing the third water-soluble film and the fourth water-soluble film together to form at least a second closed intermediate article;

i. bringing the first closed intermediate article and the second closed intermediate article into contact with one another such that the second water-soluble film and the third water-soluble film are brought into contact with one another;

j. creating at least a partial seal between the second water-soluble film and third water-soluble film to create the water-soluble unit dose article.