Flexible, porous, dissolvable solid sheet articles containing cationic surfactant

1. A process of making a solid sheet article, wherein the process comprises:

a) preparing a wet pre-mixture comprising a water-soluble polymer comprising polyvinyl alcohol, a plasticizer comprising glycerin, a cationic surfactant comprising diethyl ester dimethyl ammonium chloride, starch, and water, wherein the weight ratio of said plasticizer over said cationic surfactant is from 1.0 to 1.8;

b) aerating said wet pre-mixture to form an aerated wet pre-mixture;

c) forming said aerated wet pre-mixture into a sheet having opposing first and second sides; and

d) drying said formed sheet to make the solid sheet article.

2. The process of making a solid sheet article of claim 1 , wherein the weight ratio of said plasticizer over said cationic surfactant is from 1.2 to about 1.6.

3. The process of claim 1 , wherein said water-soluble polymer further comprises a polyvinylpyrrolidone, a polyalkylene oxide, a pullulan, a gelatin, a hydroxypropylmethylcellulose, a methycellulose, a carboxymethycellulose, or a combination thereof.

4. The process of claim 1 , wherein the water-soluble polymer comprises from about 5% to about 50% of a polyvinyl alcohol by total weight of said solid sheet article.

5. The process of claim 1 , wherein said solid sheet article comprises from about 10% to about 40%, of said polyvinyl alcohol, and from about to about 4.5%, of said starch, by total weight of said solid sheet article.

6. The process of claim 1 , wherein the water-soluble polymer comprises from about 2% to about 30% by total weight of said solid sheet article of a first polyvinyl alcohol having a first weight average molecular weight of about 15,000 to about 35,000 Daltons and from about 6% to about 30% by total weight of said solid sheet article of a second polyvinyl alcohol having a second weight average molecular weight of about from 50,000 to about 150,000 Daltons.

7. The process of claim 1 , wherein said solid sheet article further comprises from about 0.5% to about 8% of a non-ionic surfactant by total weight of said solid sheet article.

8. The process of claim 1 , wherein said solid sheet article is characterized by:

a Percent Open Cell Content of from about 85% to about 100%;

an Overall Average Pore Size of from about 150 μm to about 1000 μm;

an Average Cell Wall Thickness of from about 5 μm to about 200 μm;

a final moisture content of from about 0.5% to about 25% by weight of said solid sheet article;

a thickness of each sheet being from about 0.5 mm to about 4 mm;

a basis weight of from about 50 grams/m 2 to about 250 grams/m 2 ;

a density of from about 0.05 grams/cm 3 to about 0.5 grams/cm 3 ;

a Specific Surface Area of from about 0.03 m 2 /g to about 0.25 m 2 /g; or

a combination thereof.

9. The process of claim 1 , wherein said cationic surfactant further comprises behenyl trimethyl ammonium chloride; stearyl trimethyl ammonium chloride; cetyl trimethyl ammonium chloride; lauryl trimethyl ammonium chloride; hydrogenated tallow alkyl trimethyl ammonium chloride, dimethyl hydroxyethyl lauryl ammonium chloride; dialkyl (14-18) dimethyl ammonium chloride; ditallow alkyl dimethyl ammonium chloride; dihydrogenated tallow alkyl dimethyl ammonium chloride; distearyl dimethyl ammonium chloride; dicetyl dimethyl ammonium chloride; N,N-di (acyl-oxy ethyl)-N,N-dimethylammonium chloride; N,N-di(acyl-oxyisopropyl)-N,N-dimethylammonium methyl sulfate; N,N-di(acyl-oxyethyl)-N,N-methylhydroxyethylammonium methylsulfate; or a combination thereof.

10. The process of making a solid sheet article of claim 1 , wherein the step d) is conducted for a duration from about 5 min to about 300 min, at a temperature from about 70° C. to about 200° C., along a heating direction that forms a temperature gradient decreasing from the first side to the second side of the formed sheet, wherein the heating direction is substantially opposite to the gravitational direction for more than half of the drying time.

11. The process of making a solid sheet article of claim 1 , wherein the wet pre-mixture has a viscosity of from about 1,000 cps to about 25,000 cps measured at 40° C. and 1 s −1 .

12. The process of making a solid sheet article of claim 1 , wherein the aerated wet pre-mixture has a density of about 0.05 g/ml to about 0.7 g/ml.

13. The process of making a solid sheet article of claim 1 , wherein the aerated wet pre-mixture has a density of about 0.2 g/ml to about 0.5 g/ml.

14. The process of making a solid sheet article of claim 1 , wherein the aerated wet pre-mixture has a density of about 0.25 g/ml to about 0.45 g/ml.