Method of handling or manipulating flexible, dissolvable, porous articles

Abstract

To provide a method of handling or manipulating a flexible, dissolvable, porous article that is highly compressible and reboundable.SOLUTION: This method comprises: d) providing a flexible, dissolvable, porous article comprising a water-soluble polymer and a surfactant, wherein the article is characterized by: (1) a 50% compression force of less than 20,000 N / m2 and (2) a 90% rebound time of less than 5 minutes, when measured at 25°C with an equilibrium humidity of 40%; e) applying a force ranging from 500 N / m2 to 100,000 N / m2 to the article at a temperature ranging from 20°C to 40°C and an equilibrium humidity ranging from 20% to 95%, so as to achieve a volumetric compression of 50% or more; and f) removing the force from the compressed article so as to achieve a volumetric rebound of about 80% or more in less than 10 minutes.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method of handling or manipulating a flexible, water-soluble porous article.

Background Art

[0002] In recent years, flexible and water-soluble sheets containing surfactants and / or other active ingredients in a water-soluble polymer carrier or matrix have become well-known. Such sheets are particularly useful for delivering surfactants and / or other active ingredients upon dissolution in water. Compared to conventional granular or liquid forms within the same product category, such sheets have better structural integrity, are more concentrated, and are easier to store, transport / shipping, carry, and handle. Compared to solid tablet forms within the same product category, such sheets are more flexible, less brittle, and have better sensory appeal to consumers.

[0003] To deliver a sufficient amount of surfactants and / or other active ingredients to achieve the desired benefits, such flexible and water-soluble sheets are made thicker or multiple such sheets are stacked together to form a flexible and water-soluble article having a three-dimensional structure, which can then be made into a finished product of any shape and / or color, thereby providing a great degree of freedom in product design to delight consumers.

[0004] However, such three-dimensional flexible and water-soluble articles may have the problem that their dissolution rate in water is significantly slower compared to thinner or single-layer flexible and water-soluble sheets. Similarly, such flexible and water-soluble articles are given high porosity to improve their solubility. On the one hand, high porosity effectively improves the dissolution rate of the resulting article. However, on the other hand, it may significantly increase the overall volume of such articles, resulting in the finished product being too bulky and taking up too much space, especially during transportation and storage.

Summary of the Invention

Means for Solving the Problems

[0005] The present invention provides a solution to the above-mentioned problems by providing a highly compressible and recoverable flexible soluble porous article that can be initially compressed to reduce its volume (thereby being suitable for transportation and storage) and subsequently decompressed to return to its original volume and / or shape (thereby being ready for use).

[0006] In one aspect, the present invention is a method of handling or operating a flexible soluble porous article, the method comprising: a) providing a flexible soluble porous article comprising a water-soluble polymer and a surfactant, the flexible soluble porous article being characterized by (1) a compressive force of less than 20,000 N / m and (2) a 90% recovery time of less than 5 minutes when measured at 25°C and an equilibrium humidity of 40%; 2 a step; b) applying a force in the range of 500 N / m 2 to 100,000 N / m 2 to the flexible soluble porous article at a temperature in the range of 20°C to 40°C and an equilibrium humidity in the range of 20% to 95% so as to achieve a volume compression of 50% or more; c) removing the force from the compressed flexible soluble porous article so as to achieve a volume recovery of 80% or more in less than 10 minutes. The method relates to a method.

[0007] The force applied in step (b) can be selected from the group consisting of pressure, vacuum force, suction force, torque, and combinations thereof. Preferably, the force applied in step (b) is pressure or vacuum force, or a combination thereof.

[0008] In another aspect, the present invention is a method of packaging a flexible soluble porous article, the method comprising: a) Providing a flexible, soluble, porous article comprising a water-soluble polymer and a surfactant, wherein the flexible, soluble, porous article is characterized by an average compressive force of less than 100,000 N / m when measured at 25 °C and an equilibrium humidity of 40%; 2 and, b) Placing one or more of the flexible, soluble, porous articles within a fluid-impermeable package; c) Applying a vacuum force to the flexible, soluble, porous article to achieve a volume compression of 20% or more; d) Sealing the fluid-impermeable package having the compressed flexible, soluble, porous article therein. The present invention relates to a method comprising these steps.

[0009] In yet another aspect, the present invention relates to a compressed, flexible, soluble, porous article comprising a water-soluble polymer and a surfactant, wherein the compressed article is characterized by a volume increase of 20% or more within less than 10 minutes under reduced pressure.

[0010] In yet another aspect, the present invention relates to a package for a flexible, soluble, porous article comprising a water-soluble polymer and a surfactant, wherein the article is placed inside the package in a compressed state with a volume reduction of at least 10%, preferably at least 15%, more preferably 20% or more. This package in one aspect can be either flexible (e.g., a laminated pouch or sachet) or rigid (e.g., a heat-formed container or a molded container).

[0011] These and other aspects of the present invention will become more apparent by reading the following detailed description of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] I. Definitions As used herein, the term "flexibility" means the ability of an article to withstand stress without breaking or undergoing significant damage when bent at 90° along a center line perpendicular to its longitudinal direction. Preferably, such an article is capable of undergoing significant elastic deformation and is characterized by a Young's modulus of 5 GPa or less, preferably 1 GPa or less, more preferably 0.5 GPa or less, and most preferably 0.2 GPa or less.

[0013] As used herein, the term "solubility" refers to the ability of an article to dissolve completely or substantially in a sufficient amount of deionized water within 8 hours at 20°C and under atmospheric pressure without any stirring, with the residue of insoluble matter remaining less than 5 wt%.

[0014] As used herein, the term "solid" refers to the ability of an article to substantially retain its shape (i.e., without any visible change in its shape) at 20°C and under atmospheric pressure when the article is unrestricted and no external force is applied to it.

[0015] As used herein, the term "sheet" refers to a non-fibrous structure having a three-dimensional shape, i.e., thickness, length, and width, where both the aspect ratio of length to thickness and the aspect ratio of width to thickness are at least about 5:1, and the ratio of length to width is at least about 1:1. Preferably, both the aspect ratio of length to thickness and the aspect ratio of width to thickness are at least about 10:1, more preferably at least about 15:1, and most preferably at least about 20:1, and the aspect ratio of length to width is preferably at least about 1.2:1, more preferably at least about 1.5:1, and most preferably at least about 1.618:1.

[0016] As used herein, the term "open-cell foam" or "open-cell pore structure" refers to a solid interconnected polymer-containing matrix that contains a gas, typically a gas (such as air), and defines a network of voids or bubbles that maintains its foam structure during drying without collapsing, thereby maintaining physical strength and solid cohesiveness. The interconnectedness of the structure can be described by the open-cell content (%) measured by Test 2 disclosed below.

[0017] As used herein, the term "water-soluble" refers to the ability of a sample material to completely dissolve or disperse in water without leaving a visible solid or forming a visible separate phase, at 20 °C and under atmospheric pressure, with sufficient agitation, of at least about 25 grams, preferably at least about 50 grams, more preferably at least about 100 grams, and most preferably at least about 200 grams of such material in 1 liter (1 L) of deionized water.

[0018] The terms "essentially free of" or "essentially free from" mean that the indicated substance is present in extremely small amounts, not intentionally added to the composition or product, or preferably, does not exist at a detectable concentration by analysis in such a composition or product. Compositions or products may be included in which the indicated substance is present only as one or more impurities of the substances intentionally added to such a composition or product.

[0019] As used herein, the term "volume compression" is defined as follows.

[0020]

Number

[0021] As used herein, the term "volume restoration" is defined as follows.

[0022] [Number] Wherein, Vc is the volume of the compressed flexible and soluble porous article before the force is removed (i.e., before decompression), and Vr is the volume of the flexible and soluble porous article after the force has been removed over a specific duration (i.e., after decompression). Both volumes are measured at 25°C and an equilibrium humidity of 40%.

[0023] II. Handling / Operation of Flexible Porous Soluble Articles The present invention provides a method for handling or operating a flexible soluble porous article by compression and decompression, thereby improving efficiency and reducing the costs of its transportation and storage.

[0024] The flexible soluble porous article is preferably highly compressible and recoverable. For example, the flexible soluble porous article can be characterized by (1) a 50% compression force of less than 20,000 N / m 2 preferably less than 12,000 N / m 2 more preferably less than 6,000 N / m 2 most preferably less than 3,000 N / m 2 and (2) a 90% recovery time of less than 5 minutes, preferably less than 2 minutes, more preferably less than 1 minute, and most preferably less than 30 seconds. Both the 50% compression force and the 90% recovery time are measured at 25°C and an equilibrium humidity of 40% according to the method described below in Test 1.

[0025] The method of handling or operating the above-mentioned highly compressible and recoverable article is to achieve a volume compression of 50% or more at a temperature in the range of 20°C to 40°C and an equilibrium humidity in the range of 20% to 95%, with a force of 500 N / m 2 to 100,000 N / m 2A compression step can be included in which a moderate force within a certain range is applied to the flexible and soluble porous article. The force applied during the compression step can be selected from the group consisting of pressure, vacuum force, suction force, torque, and combinations thereof. Preferably, the force is either pressure or vacuum force, or a combination of both. The present invention achieves significant volume compression of the flexible and soluble porous article by applying a relatively moderate force under relatively normal manufacturing / transportation / storage conditions (i.e., without requiring special treatment conditions), thereby enabling its efficient and low-cost transportation and storage.

[0026] A method of handling or operating the above-described highly compressible and recoverable article further includes a decompression step in which, after the compression step, the previously applied force is removed from the compressed article so as to achieve a volume recovery of 80% or more in less than 10 minutes. Since the compressed article can recover to its original volume and / or shape completely or almost completely within a relatively short duration during decompression, its pore structure and the corresponding dissolution rate in water are not significantly affected by compression and decompression. More importantly, the aesthetic appeal of the flexible and soluble porous article to consumers is maintained despite the severe compression and decompression steps.

[0027] In a specific example of the present invention, pressure is applied to the flexible and soluble porous article by a human hand (e.g., the hand of a manufacturer, transporter, consumer, etc.) so as to achieve a volume compression of 50% or more under the above-described conditions (i.e., a temperature in the range of 20°C to 40°C and an equilibrium humidity in the range of 20% to 95%). In this specific example, the compression step can be easily achieved by a human hand in an attempt to test or demonstrate the high compressibility of the finished product, or in an attempt to prepare the product for transportation or storage.

[0028] In another specific example of the present invention, under the above-mentioned conditions (i.e., at a temperature in the range of 20°C to 40°C and an equilibrium humidity in the range of 20% to 95%), pressure is applied to the flexible and soluble porous article by a compression plate on the packaging line so as to achieve a volume compression of 50% or more. Next, for transportation and storage as a finished product, one or more compressed articles can be placed in a fluid-impermeable package. The fluid-impermeable package continues to apply an equivalent pressure within the range specified above on the compressed article(s) during transportation and storage. When the finished product reaches the consumer, the fluid-impermeable package is opened and the applied pressure is removed. Immediately, the compressed article begins to recover and can recover completely or almost to its original volume and / or shape within a relatively short time frame.

[0029] In yet another example of the present invention, one or more of the flexible and soluble porous articles are first placed in a fluid-impermeable package, and then a vacuum force is applied to the article(s) by a vacuum suction device on the packaging line to achieve a volume compression of 50% or more under the above-mentioned conditions (i.e., at a temperature in the range of 20°C to 40°C and an equilibrium humidity in the range of 20% to 95%). When the above-mentioned compression is achieved, the fluid-impermeable package is sealed to form a finished product ready for transportation and storage. The sealed fluid-impermeable package continues to apply an equivalent vacuum force within the range specified above on the compressed article(s) during transportation and storage. When the finished product reaches the consumer, the sealed fluid-impermeable package is opened, for example, by the consumer breaking the seal of the package, and the applied vacuum force is removed. Immediately, the compressed article begins to recover and can recover completely or almost to its original volume and / or shape within a relatively short time frame.

[0030] The present invention also includes a method of vacuum-packaging a flexible and soluble porous article that is necessarily compressible and recoverable as described above. To enable vacuum packaging, the flexible and soluble porous article has a value of less than 100,000 N / m 2 when measured at 25°C and an equilibrium humidity of 40%, preferably less than 25,000 N / m 2less than, more preferably 20,000 N / m 2 less than, most preferably 15,000 N / m 2 It is sufficient to have a 50% compressive force or less. Such flexible and soluble porous articles can be easily vacuum packaged to achieve a reasonable volume compression that still allows for a significant improvement in transport and storage efficiency and a reduction in associated costs. Specifically, one or more such flexible and soluble porous articles are placed within a fluid-impermeable package, and then a vacuum force is applied to the flexible and soluble porous articles to achieve a volume compression of 20% or more, preferably 30% or more, more preferably 40% or more, or most preferably 50% or more. The vacuum packaging process described above can be easily achieved by any vacuum packaging device known in the art.

[0031] Once the desired volume compression is achieved, the fluid-impermeable package is sealed with the compressed flexible and soluble porous article inside and then transported and stored as a finished product. Thereafter, upon decompression (such as achieved by opening the sealed fluid-impermeable package), the compressed article can recover to substantially or completely its original volume and / or shape. Preferably, the compressed article is characterized by a volume recovery of 20% or more, preferably 40% or more, more preferably 60% or more, or most preferably 80% or more within less than 10 minutes upon decompression.

[0032] III. Physical Structure and Properties of Flexible and Soluble Porous Articles The flexible and water-soluble porous article of the present invention is preferably characterized by an open-celled foam (OCF) structure that allows for easier water penetration into the sheet and faster dissolution of the sheet in water. For example, such an article may have (i) a continuous bubble content of about 80% to 99%, preferably about 85% to 99%, more preferably about 90% to 99% as measured by Test 2 below, and (ii) an overall average pore size of about 100 μm to about 2000 μm, preferably about 150 μm to about 1000 μm, more preferably about 200 μm to about 600 μm as measured by the Micro-CT method described in Test 3 below. The overall average pore size defines the porosity of the OCF structure of the present invention. The continuous bubble content defines the interconnectivity between the pores in the OCF structure of the present invention. The interconnectivity of the OCF structure can also be described by the star volume or Structure Model Index (SMI) disclosed in International Publication Nos. 2010 / 077627 and 2012 / 138820.

[0033] Preferably, the flexible and water-soluble porous article of the present invention is further characterized by an average bubble wall thickness of about 5 μm to about 200 μm, preferably about 10 μm to about 100 μm, more preferably about 10 μm to about 80 μm as measured by Test 3 below.

[0034] The article of the present invention can have any suitable shape, either regular or irregular, such as spherical, cubic, rectangular, polygonal, elliptical, cylindrical, rod-shaped, sheet-shaped, flower-shaped, fan-shaped, star-shaped, disk-shaped, etc. The article of the present invention is characterized by a maximum dimension D and a minimum dimension z (perpendicular to the maximum dimension), and the D / z ratio (hereinafter also referred to as the "aspect ratio") can range from 1 to about 10, preferably about 1.4 to about 9, preferably about 1.5 to about 8, more preferably about 2 to about 7. When the aspect ratio is 1, the article has a spherical shape. When the aspect ratio is about 1.4, the article has a cubic shape. The article of the present invention may have a minimum dimension z greater than about 3 mm but less than about 20 cm, preferably about 4 mm to about 10 cm, more preferably about 5 mm to about 30 mm.

[0035] The flexible and soluble porous article of the present invention may have a single-layer structure made of a thick flexible and soluble porous sheet. Alternatively, the flexible and soluble porous article of the present invention may preferably have a multi-layer structure including a plurality of flexible and soluble porous sheets stacked together in a self-adhesive manner without adding an adhesive. Each of the flexible and soluble porous sheets may have a thickness in the range of about 0.5 mm to about 4 mm, preferably about 0.6 mm to about 3.5 mm, more preferably about 0.7 mm to about 3 mm, even more preferably about 0.8 mm to about 2 mm, and most preferably about 1 mm to about 1.5 mm, as measured in Test 4 below. The multi-layer structure can include any number, for example, about 4 to about 50 sheets, preferably about 5 to about 40 sheets, more preferably about 6 to about 30 sheets of the above-mentioned sheets. In a particularly preferred embodiment of the present invention, the multi-layer structure includes 15 to 40 layers of the above-mentioned flexible and soluble porous sheets and has an aspect ratio in the range of about 2 to about 7.

[0036] The flexible and soluble porous article of the present invention may contain a small amount of water. Preferably, the flexible and soluble porous article of the present invention is characterized by a final moisture content of 0.5 wt% to 25 wt%, preferably 1 wt% to 20 wt%, more preferably 3 wt% to 10 wt% of the solid sheet, as measured by Test 5 below. The appropriate final moisture content in the resulting solid sheet can ensure the desired flexibility / deformability of the sheet and provide a soft / smooth feel to the consumer. If the final moisture content is too low, the sheet may be too brittle or too rigid. If the final moisture content is too high, the sheet may be too sticky and its overall structural integrity may be impaired.

[0037] The flexible and soluble porous article of the present invention is about 50 g / m as measured by Test 6 below 2 ~ about 500 g / m 2 、preferably about 150 g / m 2 ~ about 450 g / m 2 、more preferably about 250 g / m 2~about 400 grams / m 2 It may be further characterized by the basis weight thereof.

[0038] Furthermore, the flexible soluble porous article of the present invention has a density of about 0.05 grams / cm 3 ~about 0.5 grams / cm 3 , preferably about 0.06 grams / cm 3 ~about 0.4 grams / cm 3 , more preferably about 0.07 grams / cm 3 ~about 0.2 grams / cm 3 , most preferably about 0.08 grams / cm 3 ~about 0.15 grams / cm 3 as measured by Test 7 below. The density of the article of the present invention can indicate its porosity. For example, the lower the density, the more porous the article and the faster its dissolution rate, which can affect its dissolution rate.

[0039] Furthermore, the flexible soluble porous article of the present invention has a specific surface area of about 0.03 m 2 / g~about 0.25 m 2 / g, preferably about 0.04 m 2 / g~about 0.22 m 2 / g, more preferably 0.05 m 2 / g~0.2 m 2 / g, most preferably 0.1 m 2 / g~0.18 m 2 / g as measured by Test 8 below. The specific surface area of the article of the present invention can also indicate its porosity. For example, the larger the specific surface area, the more porous the article and the faster its dissolution rate, which can affect its dissolution rate.

[0040] In a preferred embodiment, the flexible soluble porous article according to the present disclosure and / or the soluble solid article according to the present disclosure is / are ·a continuous bubble content of 85% to 99%, preferably 90% to 99%, and / or ·an overall average pore diameter of 150 μm to 1000 μm, preferably 200 μm to 600 μm, and / or · An average bubble wall thickness of 5 μm to 200 μm, preferably 10 μm to 100 μm, more preferably 10 μm to 80 μm, and / or · A final water content of 0.5 wt% to 25 wt% of the article, preferably 1 wt% to 20 wt%, more preferably 3 wt% to 10 wt%, and / or · About 50 g / m 2 ~ about 500 g / m 2 、 preferably about 150 g / m 2 ~ about 450 g / m 2 、 more preferably about 250 g / m 2 ~ about 400 g / m 2 の basis weight, and / or · 0.05 g / cm 3 ~ 0.5 g / cm 3 、 preferably 0.06 g / cm 3 ~ 0.4 g / cm 3 、 more preferably 0.07 g / cm 3 ~ 0.2 g / cm 3 、 most preferably 0.08 g / cm 3 ~ 0.15 g / cm 3 の density, and / or · 0.03 m 2 / g ~ 0.25 m 2 / g、 preferably 0.04 m 2 / g ~ 0.22 m 2 / g、 more preferably 0.05 m 2 / g ~ 0.2 m 2 / g、 most preferably 0.1 m 2 / g ~ 0.18 m 2 / g of specific surface area.

[0041] III. Formulations of Flexible Porous Soluble Articles The flexible porous soluble articles of the present invention contain at least a water-soluble polymer and a surfactant.

[0042] The water-soluble polymer in the flexible porous soluble article can function as a film-forming agent, a structuring agent, and a carrier for other active ingredients (such as surfactants, emulsifiers, builders, chelating agents, fragrances, colorants, etc.).

[0043] The water-soluble polymer may be present in the flexible porous soluble article of the present invention in an amount in the range of about 5% to about 50%, preferably about 8% to about 40%, more preferably about 10% to about 30%, and most preferably about 11% to about 25% of the total weight of the article. In a particularly preferred embodiment of the present invention, the total amount of the water-soluble polymer(s) present in the flexible porous soluble article of the present invention is about 25% or less of the total weight of such an article.

[0044] Water-soluble polymers suitable for use in the practice of the present invention may be selected that have a weight average molecular weight in the range of about 50,000 to about 400,000 Daltons, preferably about 60,000 to about 300,000 Daltons, more preferably about 70,000 to about 200,000 Daltons, and most preferably about 80,000 to about 150,000 Daltons. The weight average molecular weight is calculated by adding the average molecular weights of each polymer raw material and multiplying by the respective relative weight percentages by weight of the total weight of the polymer present within the porous solid. The weight average molecular weight of the water-soluble polymer as used herein may affect the viscosity of the wet premix, which in turn can affect the number and size of air bubbles during the aeration step and the pore expansion / opening results during the drying step. Further, the weight average molecular weight of the water-soluble polymer can affect the overall film-forming properties of the wet premix and the compatibility / incompatibility with certain surfactants.

[0045] The water-soluble polymer of the present invention may be selected from synthetic polymers, naturally-derived polymers, or modified natural polymers.

[0046] Suitable synthetic polymers include polyvinyl alcohol, polyvinyl pyrrolidone, polyalkylene oxide, polyacrylate, caprolactam, polymethacrylate, polymethyl methacrylate, polyacrylamide, polymethyl acrylamide, polydimethylacrylamide, polyethylene glycol monomethacrylate, a copolymer of acrylic acid and methyl acrylate, polyurethane, polycarboxylic acid, polyvinyl acetate, polyester, polyamide, polyamine, polyethyleneimine, maleic acid / (acrylate or methacrylate) copolymer, a copolymer of methyl vinyl ether and maleic anhydride, a copolymer of vinyl acetate and crotonic acid, a copolymer of vinyl pyrrolidone and vinyl acetate, a copolymer of vinyl pyrrolidone and caprolactam, a vinyl pyrrolidone / vinyl acetate copolymer, a copolymer of an anionic monomer, a cationic monomer, and an amphoteric monomer, and combinations thereof.

[0047] Preferred water-soluble polymers of the present invention include polyvinyl alcohol, polyvinyl pyrrolidone, polyalkylene oxide, starch and starch derivatives, pullulan, gelatin, hydroxypropyl methylcellulose, methylcellulose, and carboxymethylcellulose. A more preferred water-soluble polymer of the present invention contains polyvinyl alcohol, and in particular, polyvinyl alcohol characterized by a degree of hydrolysis in the range of about 40% to about 100%, preferably about 50% to about 95%, more preferably about 65% to about 92%, and most preferably about 70% to about 90%. Commercially available polyvinyl alcohols include those under the trade name CELVOL from Celanese Corporation (Texas, USA), including but not limited to CELVOL 523, CELVOL 530, CELVOL 540, CELVOL 518, CELVOL 513, CELVOL 508, CELVOL 504, those under the trade names Mowiol® and POVAL™ from Kuraray Europe GmbH (Frankfurt, Germany), PVA 1788 (also referred to as PVA BP17) commercially available from various suppliers including Lubon Vinylon Co. (Nanjing, China), and combinations thereof. In a particularly preferred embodiment of the present invention, the flexible porous soluble article contains polyvinyl alcohol having a weight average molecular weight in the range of 80,000 to about 150,000 daltons and a degree of hydrolysis in the range of about 80% to about 90%, which is about 10% to about 25% by weight, more preferably about 15% to about 23% by weight of the total weight of such an article.

[0048] In addition to the water-soluble polymers described above, the flexible porous soluble article of the present invention contains one or more surfactants.

[0049] Surfactants can function as emulsifiers during the aeration process (described below) to produce a sufficient amount of stable bubbles to form the desired OCF structure of the present invention. Examples of emulsifiers used herein as surfactant components include mono- and di-glycerides, aliphatic alcohols, polyglycerol esters, propylene glycol esters, sorbitan esters, and other emulsifiers commonly used to stabilize the air interface by known or other means.

[0050] Also, surfactants can function as active ingredients to achieve the desired cleaning effect. Suitable surfactants for such purposes can be selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, polymeric surfactants, or any combination thereof.

[0051] The total amount of surfactant in the flexible porous soluble article of the present invention is preferably in the range of about 30% to about 90%, preferably about 40% to about 80%, more preferably about 50% to about 70% of the total weight of the article.

[0052] Non-limiting examples of suitable anionic surfactants used herein include alkyl and alkyl ether sulfates, sulfated monoglycerides, sulfonated olefins, alkylaryl sulfonates, primary or secondary alkane sulfonates, alkyl sulfosuccinates, acyl taurates, acyl isethionates, alkyl glyceryl ether sulfonates, sulfonated methyl esters, sulfonated fatty acids, alkyl phosphates, acyl glutamates, acyl sarcosinates, alkyl sulfacetates, acylated peptides, alkyl ether carboxylates, acyl lactylates, anionic fluorosurfactants, sodium lauroyl glutamate, and combinations thereof.

[0053] One category of anionic surfactants particularly suitable for the practice of the present invention is C6 - C 20Examples include linear or branched alkylalkoxy sulfates (AAS). Among this category, linear or branched alkylethoxy sulfates (AES) having the corresponding formula RO(C2H4O) x SO3M are particularly preferred, where R is an alkyl or alkenyl having about 6 to about 20 carbon atoms, x is from 1 to 10, and M is a water-soluble cation such as ammonium, sodium, potassium, and triethanolamine. Preferably, R has about 6 to about 18, preferably about 8 to about 16, more preferably about 10 to about 14 carbon atoms. AES surfactants are typically prepared as condensation products of ethylene oxide with a monohydric alcohol having about 6 to about 20 carbon atoms. Useful alcohols can be derived from fats such as coconut oil or tallow or can be synthetic. In the present specification, lauryl alcohol and linear alcohol derived from coconut oil are preferred. Such alcohols are reacted with ethylene oxide in a molar ratio of about 0.1 to about 10, preferably about 0.5 to about 5, particularly about 1 to 3, and for example, the resulting mixture of molecular species having an average of 1 to 3 moles of ethylene oxide per mole of alcohol is sulfated and neutralized. Highly preferred AES are those containing a mixture of individual compounds, and the mixture has an average alkyl chain length of about 10 to about 16 carbon atoms and an average degree of ethoxylation of about 1 to about 4 moles of ethylene oxide.

[0054] Another category of anionic surfactants particularly suitable for the practice of the present invention includes C6 - C 20 linear alkylbenzene sulphonate (LAS) surfactants. Exemplary C 10 - C 20 linear alkylbenzene sulphonates useful in the present invention include C 10 - C 20 alkali metal salts, alkaline earth metal salts, or ammonium salts of linear alkylbenzene sulfonic acids, preferably C 11 - C18 or C 11 ~C 14 Examples include sodium, potassium, magnesium, and / or ammonium salts of linear alkylbenzene sulfonic acid. More preferred are C 12 and / or C 14 sodium or potassium salts of linear alkylbenzene sulfonic acid, and most preferred are C 12 and / or C 14 sodium salts of linear alkylbenzene sulfonic acid, namely, sodium dodecylbenzenesulfonate or sodium tetradecylbenzenesulfonate.

[0055] Another category of anionic surfactants suitable for the practice of the present invention includes sodium trideceth sulfates (STS) having a weight average degree of alkoxylation in the range of about 0.5 to about 5, preferably about 0.8 to about 4, more preferably about 1 to about 3, and most preferably about 1.5 to about 2.5. Trideceth is, in one embodiment, a branched-chain alkoxylated hydrocarbon of 13 carbons containing on average at least one methyl branch per molecule. STS used in the present invention can include ST(EOxPOy)S, where EOx represents a repeating ethylene oxide unit having a repeat number x in the range of 0 to 5, preferably 1 to 4, more preferably 1 to 3, and POy represents a repeating propylene oxide unit having a repeat number y in the range of 0 to 5, preferably 0 to 4, more preferably 0 to 2. For example, a material such as ST2S having a weight average ethoxylation degree of about 2 may contain significant amounts of molecules having no ethoxylate, 1 mole of ethoxylate, 3 moles of ethoxylate, etc., and the distribution of ethoxylation can be broad, narrow, or truncated and still result in a total weight average ethoxylation degree of about 2. STS is particularly suitable for personal cleansing applications.

[0056] Another category of anionic surfactants suitable for the practice of the present invention includes alkyl sulfates. These substances have the corresponding formula: ROSO3M, where R is an alkyl or alkenyl of about 6 to about 20 carbon atoms, x is 1 to 10, and M is a water-soluble cation such as ammonium, sodium, potassium, and triethanolamine. Preferably, R has about 6 to about 18 carbon atoms, preferably about 8 to about 16 carbon atoms, and more preferably about 10 to about 14 carbon atoms.

[0057] Other suitable anionic surfactants include water-soluble salts of organic sulfuric acid reaction products of the general formula [R 1 -SO3-M], where R 1 is selected from the group consisting of straight-chain or branched-chain saturated aliphatic hydrocarbon radicals having about 6 to about 20 carbon atoms, preferably about 10 to about 18 carbon atoms, and M is a cation. Alkali metal and ammonium sulfonated C 10~18 n-paraffins are preferred. Other suitable anionic surfactants include olefin sulfonates having about 12 to about 24 carbon atoms. The α-olefins from which the olefin sulfonates are derived are mono-olefins having about 12 to about 24 carbon atoms, preferably about 14 to about 16 carbon atoms. Preferably, they are linear olefins.

[0058] Other suitable anionic surfactants include β-alkyloxyalkane sulfonates, reaction products of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide, sodium or potassium salts of fatty acid amides of methyl tauride, succinamates, and ester derivatives of sodium sulfosuccinate.

[0059] Examples of nonionic surfactants that may be included in the articles of the present invention include, but are not limited to, alkyl alkoxylated alcohols, alkyl alkoxylated phenols, alkyl polysaccharides (especially alkyl glucosides and alkyl polyglucosides), polyhydroxy fatty acid amides, alkoxylated fatty acid esters, sucrose esters, sorbitan esters and alkoxylated derivatives of sorbitan esters, amine oxides, and any conventional nonionic surfactant. Preferred nonionic surfactants have the formula R 1 (OC2H4) n OH, where R 1 is a C8 - C 18 alkyl group or an alkylphenyl group, and n is from about 1 to about 80. Particularly preferred are C8 - C 18 alkyl ethoxylated alcohols having a weight average degree of ethoxylation of from about 1 to about 20, preferably from about 5 to about 15, more preferably from about 7 to about 10, such as the NEODOL® nonionic surfactants commercially available from Shell. Other non - limiting examples of nonionic surfactants useful herein include C6 - C 12 alkylphenol alkoxylates where the alkoxylate units can be ethyleneoxy units, propyleneoxy units, or mixtures thereof; C 12 -C 18 alcohols and C6 - C 12 alkylphenol condensates (Pluronic®) (BASF) with ethylene oxide / propylene oxide block polymers; C 14 -C 22 medium - chain branched alcohols (BA); C 14 -C 22 medium - chain branched alkyl alkoxylates, BAE x (where x is from 1 to 30); alkyl polysaccharides, specifically alkyl polyglycosides; polyhydroxy fatty acid amides; and ether - terminated poly(oxyalkylated) alcohol surfactants. Suitable nonionic surfactants also include those sold by BASF under the trade name Lutensol®.

[0060] In a preferred embodiment, examples of the nonionic surfactant selected from sorbitan esters and alkoxylated derivatives of sorbitan esters include sorbitan monolaurate (SPAN® 20), sorbitan monopalmitate (SPAN® 40), sorbitan monostearate (SPAN® 60), sorbitan tristearate (SPAN® 65), sorbitan monooleate (SPAN® 80), sorbitan trioleate (SPAN® 85), sorbitan isostearate, polyoxyethylene (20) sorbitan monolaurate (Tween® 20), polyoxyethylene (20) sorbitan monopalmitate (Tween® 40), polyoxyethylene (20) sorbitan monostearate (Tween® 60), polyoxyethylene (20) sorbitan monooleate (Tween® 80), polyoxyethylene (4) sorbitan monolaurate (Tween® 21), polyoxyethylene (4) sorbitan monostearate (Tween® 61), polyoxyethylene (5) sorbitan monooleate (Tween® 81) (all of which are available from Uniqema), and combinations thereof.

[0061] The most preferred nonionic surfactant for the practice of the present invention is a C6 - C linear or branched alkyl alkoxylated alcohol (alkylalkoxylated alcohols, AA), more preferably a C linear alkoxylated alcohol having a weight average degree of alkoxylation in the range of 7 - 9. 20 - 12 - 14 Linear ethoxylated alcohols are included.

[0062] Suitable amphoteric surfactants for use in the articles of the present invention include those widely described as derivatives of aliphatic secondary and tertiary amines, wherein the aliphatic radical may be straight or branched, and one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water-soluble group such as carboxy, sulfonate, sulfate, phosphate or phosphonate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, sodium 3-dodecylaminopropanesulfonate, sodium lauryl sarcosinate, N-alkyltaurines such as those prepared by reacting dodecylamine with sodium isethionate, and N-higher alkyl aspartic acids.

[0063] One category of amphoteric surfactants particularly suitable for incorporation into articles for personal care applications (such as shampoos, facial or body cleansers, etc.) includes alkyl amphoacetates such as lauro amphoacetate and coco amphoacetate. Alkyl amphoacetates can consist of monoacetates and diacetates. In some types of alkyl amphoacetates, the diacetate is an impurity or an unintended reaction product. When alkyl amphoacetate(s) is present in the solid sheet of the present invention, the amount may range from about 2% to about 40%, preferably from about 5% to about 30%, more preferably from about 10% to about 20% of the total weight of the article.

[0064] Suitable zwitterionic surfactants include those widely described as derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds, wherein the aliphatic radical can be straight or branched and one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic group such as carboxy, sulfonate, sulfate, phosphate or phosphonate.

[0065] Other suitable zwitterionic surfactants for use in this specification include betaines such as coco dimethyl carboxymethyl betaine, cocoamidopropyl betaine, coco betaine, laurylamidopropyl betaine, oleyl betaine, lauryl dimethyl carboxymethyl betaine, lauryl dimethyl α-carboxyethyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl) carboxymethyl betaine, stearyl bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl dimethyl γ-carboxypropyl betaine, and lauryl bis-(2-hydroxypropyl) α-carboxyethyl betaine. Sulfobetaines can be represented by coco dimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, lauryl dimethyl sulfoethyl betaine, lauryl bis-(2-hydroxyethyl) sulfopropyl betaine, etc., and amide betaines and amide sulfobetaines in which the RCONH(CH2)3 radical (wherein R is C 11 ~C 17 alkyl) is attached to the nitrogen atom of the betaine are also useful in the present invention.

[0066] Cationic surfactants can also be utilized in the present invention, particularly in fabric softener and hair conditioner products. When used in making products containing a cationic surfactant as the main surfactant, such cationic surfactants are preferably present in an amount in the range of about 2% to about 30%, preferably about 3% to about 20%, more preferably about 5% to about 15% based on the total weight of the solid sheet.

[0067] Cationic surfactants can include DEQA compounds that include diamide active ingredients and active ingredients having a mixture of amide and ester bonds. Preferred DEQA compounds are typically made by reacting alkanolamines such as MDEA (methyldiethanolamine) and TEA (triethanolamine) with fatty acids. Some substances typically obtained from such reactions include N,N-di(acyl-oxyethyl)-N,N-dimethylammonium chloride or N,N-di(acyl-oxyethyl)-N,N-methylhydroxyethylammonium methyl sulfate, wherein the acyl group is derived from animal fats, unsaturated and polyunsaturated fatty acids.

[0068] Suitable polymeric surfactants for use in the personal care compositions of the present invention include, but are not limited to, block copolymers of ethylene oxide and fatty alkyl residues, block copolymers of ethylene oxide and propylene oxide, hydrophobically modified polyacrylates, hydrophobically modified celluloses, silicone polyethers, silicone copolyol esters, ditetradecyl polydimethylsiloxane, and co-modified amino / polyether silicones.

[0069] In a preferred embodiment of the present invention, the flexible porous soluble article of the present invention further comprises a plasticizer, preferably in an amount in the range of about 0.1% to about 25%, preferably about 0.5% to about 20%, more preferably about 1% to about 15%, and most preferably 2% to 12% of the total weight of the article.

[0070] Suitable plasticizers for use in the present invention include, for example, polyols, copolyols, polycarboxylic acids, polyesters, dimethicone copolyols, and the like.

[0071] Examples of useful polyols include, but are not limited to, glycerin, diglycerin, ethylene glycol, polyethylene glycol (especially 200 - 600), propylene glycol, butylene glycol, pentylene glycol, glycerol derivatives (such as propoxylated glycerol), glycidol, cyclohexanedimethanol, hexanediol, 2,2,4 - trimethylpentane - 1,3 - diol, pentaerythritol, urea, sugar alcohols (such as sorbitol, mannitol, lactitol, xylitol, maltitol, and other mono - and polyhydric alcohols), mono -, di - and oligosaccharides (such as fructose, glucose, sucrose, maltose, lactose, high fructose corn syrup solids, and dextrin), ascorbic acid, sorbate, ethylenebisformamide, amino acids, etc.

[0072] Examples of polycarboxylic acids include, but are not limited to, citric acid, maleic acid, succinic acid, polyacrylic acid, and polymaleic acid.

[0073] Examples of suitable polyesters include, but are not limited to, glycerol triacetate, acetylated monoglyceride, diethyl phthalate, triethyl citrate, tributyl citrate, acetyl triethyl citrate, acetyl tributyl citrate.

[0074] Examples of suitable dimethicone copolyols include, but are not limited to, PEG - 12 dimethicone, PEG / PPG - 18 / 18 dimethicone, and PPG - 12 dimethicone.

[0075] Other suitable plasticizers include alkyl and allyl phthalates; naphthalates; lactates (e.g., sodium salts, ammonium salts, and potassium salts); Solvesso-30; urea; lactic acid; sodium pyrrolidone carboxylate (PCA); sodium hyaluronate or hyaluronic acid; soluble collagen; denatured proteins; monosodium L-glutamate; α&β hydroxyl acids, such as glycolic acid, lactic acid, citric acid, maleic acid, and salicylic acid; glyceryl polymethacrylate; polymeric plasticizers such as polyquaternium; proteins, and amino acids such as glutamic acid, aspartic acid, and lysine; hydrolyzed hydrogen starch products; other low molecular weight esters (e.g., C2~C 10 esters of alcohols and acids); and any other water-soluble plasticizers known to those skilled in the food and plastics industries; and mixtures thereof, but are not limited thereto.

[0076] Particularly preferred examples of plasticizers include glycerin, ethylene glycol, polyethylene glycol, propylene glycol, and mixtures thereof. The most preferred plasticizer is glycerin.

[0077] In addition to the above-mentioned components, such as water-soluble polymers, surfactant(s), and plasticizers, the flexible soluble porous article of the present invention may contain one or more additional components depending on its intended use. Such one or more additional components may be selected from the group consisting of fabric care active substances, dishwashing active substances, hard surface cleaning active substances, beauty and / or skin care active substances, personal cleansing active substances, hair care active substances, oral care active substances, feminine care active substances, baby care active substances, and any combination thereof.

[0078] Suitable fabric care active substances include organic solvents (linear or branched lower C1-C8 alcohols, diols, glycerol, or glycols; lower amine solvents such as C1-C4 alkanolamines, and mixtures thereof; more specifically, 1,2-propanediol, ethanol, glycerol, monoethanolamine, and triethanolamine), carriers, hydrotropes, builders, chelating agents, dispersants, enzymes and enzyme stabilizers, catalyst materials, bleaching agents (including optical bleaching agents) and bleach activators, fragrances (including encapsulated fragrances or fragrance microcapsules), colorants (such as pigments and dyes, including hue dyes), optical brighteners, anti-migration agents, clay stain removal / redeposition inhibitors, structuring agents, rheology modifiers, foam suppressants, processing aids, fabric softeners, antibacterial agents, etc., but are not limited thereto.

[0079] Suitable hair care active substances include class II moisture regulators for reducing shrinkage (salicylic acid and derivatives, organic alcohols, and esters), cationic surfactants (especially those with a solubility in water at 25°C of preferably less than 0.5 g / 100 g of water, more preferably less than 0.3 g / 100 g of water), high melting point aliphatic compounds (for example, aliphatic alcohols, fatty acids, and mixtures thereof having a melting point of 25°C or higher, preferably 40°C or higher, more preferably 45°C or higher, even more preferably 50°C or higher), silicone compounds, conditioning agents (hydrolyzed collagen having the trade name Peptein 2000 available from Hormel, vitamin E having the trade name Emix-d available from Eisai, panthenol available from Roche, panthenyl ethyl ether available from Roche, hydrolyzed keratin, proteins, plant extracts, and nutrients), preservatives (such as benzyl alcohol, methylparaben, propylparaben, and imidazolidinyl urea), pH adjusters (such as citric acid, sodium citrate, succinic acid, phosphoric acid, sodium hydroxide, sodium carbonate), salts (such as potassium acetate and sodium chloride), coloring agents, fragrances or perfumes, sequestering agents (such as disodium ethylenediaminetetraacetate), ultraviolet and infrared screening and absorbing agents (such as octyl salicylate), hair bleaching agents, hair perming agents, hair setting agents, anti-dandruff agents, antibacterial agents, hair growth agents or supplements, co-solvents or other additional solvents, etc., but are not limited thereto.

[0080] Suitable beauty and / or skin care active substances include those substances that are approved for use in cosmetics and are described in references such as CTFA Cosmetic Ingredient Handbook, Second Edition, The Cosmetic, Toiletries, and Fragrance Association, Inc. 1988, 1992. Further non-limiting examples of suitable beauty and / or skin care active substances include preservatives, fragrances or flavorants, colorants or dyes, thickeners, humectants, skin softeners, pharmaceutical active substances, vitamins or nutrients, sunscreens, deodorants, sensates, plant extracts, nutrients, astringents, cosmetic particles, absorbent particles, fibers, anti-inflammatory agents, skin lightening agents, skin tone modifiers (functioning to improve the overall skin tone and may include 1,3-dihydroxy-4-alkylbenzenes such as vitamin B3 compounds, sugar amines, hexamidine compounds, salicylic acid, hexylresorcinol, and retinoids), skin tanning agents, exfoliants, moisturizers, enzymes, antioxidants, free radical scavengers, anti-wrinkle active substances, anti-acne agents, acids, bases, minerals, suspending agents, pH adjusters, pigment particles, antibacterial agents, insect repellents, shaving lotion agents, co-solvents or other additional solvents, and the like.

[0081] Non-limiting examples of product type embodiments that can be formed by the flexible soluble porous article of the present invention include laundry detergent products, fabric softening products, hand washing products, hair shampoos or other hair treatment products, body cleansing products, shaving preparation products, dishwashing products, personal care substrates containing pharmaceuticals or other skin care active substances, moisturizing products, sunscreen products, beauty or skin care products, deodorant products, oral care products, feminine hygiene products, baby care products, fragrance-containing products, and the like.

[0082] IV. Manufacturing Process of Flexible Soluble Porous Sheet The flexible soluble porous article of the present invention may comprise one or more layers of a flexible porous soluble solid sheet, which (a) contains raw materials (e.g., active ingredients such as water-soluble polymers, surfactants, and optionally plasticizers) dissolved or dispersed in water or a suitable solvent, at about 40 °C and 1 s -1A step of forming a premix characterized by a viscosity of about 1,000 cps to about 25,000 cps measured at [conditions not provided]; (b) a step of aerating the premix (for example, by introducing gas into a wet slurry) to form an aerated wet premix; (c) a step of forming the aerated wet premix on a sheet having opposing first and second surfaces; and (d) a step of drying the formed sheet at a temperature of 70°C to 200°C for a drying time of 1 minute to 60 minutes along a heating direction in which a temperature gradient decreasing from the first surface to the second surface of the formed sheet is formed, wherein the heating direction is substantially offset from the direction of gravity by more than half of the drying time, that is, the step is carried out mainly under heating along a "anti-gravity" heating direction. Such a mainly "anti-gravity" heating direction can be achieved by various means including, but not limited to, bottom conduction heating / drying configurations and rotary drum heating / drying configurations.

[0083] The wet premix is generally prepared by mixing a solid of interest, which includes a water-soluble polymer, a surfactant (one or more types optional), and / or other beneficial agents, an optional plasticizer, and other optional components, with a sufficient amount of water or another solvent in a premix tank. The wet premix can be formed using a mechanical mixer. Examples of mechanical mixers useful herein include, but are not limited to, turbines having pitched blades or MAXBLEND mixers (Sumitomo Heavy Industries).

[0084] In the present invention, at 40°C and 1 s -1 It is particularly important to adjust the viscosity of the wet premix so that it is within a predetermined range of about 1,000 cps to about 25,000 cps when measured at [conditions not provided]. The viscosity of the wet premix has a significant effect on the pore expansion and pore opening of the aerated premix during the subsequent drying process, and wet premixes with different viscosities can form very different flexible porous soluble solid sheets of the foam structure. In one embodiment, the viscosity of the wet premix is at 40°C and 1 second-1 When measured, it is in the range of about 3,000 cps to about 24,000 cps, preferably about 5,000 cps to about 23,000 cps, more preferably about 10,000 cps to about 20,000 cps. The viscosity value of the premix is measured for 360 seconds using a Malvern Kinexus Lab+ rheometer (CP1 / 50 SR3468 SS) having a cone and plate geometry, at a gap width of 0.054 mm, a temperature of 40°C, and a shear rate of 1.0 reciprocal second.

[0085] In a preferred but non-essential embodiment, the solid of interest is present in the wet premix at a concentration of about 15% to about 70%, preferably about 20% to about 50%, more preferably about 25% to about 45% based on the total weight of the wet premix. The percent solids is the total weight percent based on the weight of the total processed mixture of solid, semi-solid, and liquid components, excluding any clearly volatile substances such as water and low-boiling alcohols.

[0086] Among the solids of interest in the wet premix of the present invention, there may be present about 1 wt% to about 75 wt% surfactant, about 0.1 wt% to about 25 wt% water-soluble polymer, and optionally about 0.1 wt% to about 25 wt% plasticizer, based on the total weight of the solids. Other active agents or beneficial agents can also be added to the premix.

[0087] Optionally, the wet premix is rapidly preheated prior to and / or during the aeration process at a temperature higher than the ambient temperature but lower than any temperature that causes decomposition of the components internally. In one embodiment, the wet premix is maintained at a high temperature in the range of about 40°C to about 100°C, preferably about 50°C to about 95°C, more preferably about 60°C to about 90°C, and most preferably about 75°C to about 85°C. In one embodiment, optional continuous heating is utilized prior to the aeration step. Further, additional heat can be added during the aeration process to try and maintain the wet premix at such a high temperature. This can be accomplished by conductive heating from one or more surfaces, injection of steam, or other processing means. It is believed that the act of preheating the wet premix prior to and / or during the aeration process provides a means of reducing the viscosity of the wet premix containing a higher percentage of solids, thereby improving the introduction of air bubbles into the mixture and the formation of the desired solid sheet. Achieving a higher percentage of solids is desirable as it can reduce the overall energy requirements for drying. Thus, an increase in the solid percentage can conversely result in a decrease in the water concentration content and an increase in viscosity. As described above, a wet premix with too high a viscosity is not desirable for the practice of the present invention. Preheating effectively counteracts such viscosity, thereby enabling the production of a high-speed solubility sheet even when using a premix with a high solid content.

[0088] Ventilation of the wet premix is carried out to introduce a sufficient amount of air bubbles into the wet premix to subsequently form an OCF structure inside during drying. After being sufficiently ventilated, the wet premix is characterized by a density significantly lower than that of an unventilated wet premix (which may contain slightly entrapped air bubbles) or an insufficiently ventilated wet premix (which may contain some air bubbles but at a very low volume fraction and with relatively large air bubble sizes). Preferably, the ventilated wet premix has a density in the range of about 0.05 g / mL to about 0.5 g / mL, preferably about 0.08 g / mL to about 0.4 g / mL, more preferably about 0.1 g / mL to about 0.35 g / mL, even more preferably about 0.15 g / mL to about 0.3 g / mL, and most preferably about 0.2 g / mL to about 0.25 g / mL.

[0089] Ventilation can be achieved by any of the physical or chemical means in the present invention. In one embodiment, it can be achieved, for example, by introducing gas into the wet premix through mechanical agitation using any suitable mechanical treatment means, such as a rotor stator mixer, planetary mixer, pressure mixer, non-pressure mixer, batch mixer, continuous mixer, semi-continuous mixer, high shear mixer, low shear mixer, in-water sparger, or any combination thereof, but not limited thereto. In another embodiment, it can be achieved through chemical means, for example, by using a chemical foaming agent to provide in-situ gas formation through a chemical reaction of one or more components including the formation of carbon dioxide (CO2 gas) by a foaming system.

[0090] In a particularly preferred embodiment, aeration of the wet premix is achieved by using a continuous pressure aerator or mixer conventionally utilized in the food industry in the production of marshmallows. The continuous pressure mixer serves to homogenize or aerate the wet premix and can produce a highly uniform and stable foamed structure having a uniform bubble size. The unique design of the high shear rotor / stator agitation head can result in a uniform bubble size in the layer of the continuous bubble foam. Suitable continuous pressure aerators or mixers include the Morton Whipper (Morton Machine Co., Motherwell, Scotland), the Oakes Continuous Automatic Mixer (E.T.Oakes Corporation, Hauppauge, New York), the Fedco Continuous Mixer (Peerless Group, Sidney, Ohio), the Mondo (Haas-Mondomix B.V., Netherlands), the Aeros (Aeros Industrial Equipment Co., Ltd., Guangdong Province, China), and the Preswhip (Hosokawa Micron Group, Osaka, Japan). For example, the Aeros A20 continuous aerator can be operated at a supply pump speed setting of about 300 - 800 (preferably about 500 - 700) with a mixing head speed setting of about 300 - 800 (preferably about 400 - 600), each at an air flow rate of about 50 - 150 (preferably 60 - 130, more preferably 80 - 120). In another example, the Oakes Continuous Automatic Mixer can be operated at a mixing head speed setting of about 10 - 30 rpm (preferably about 15 - 25 rpm, more preferably about 20 rpm) with an air flow rate of about 10 - 30 liters per hour (preferably about 15 - 25 L / h, more preferably about 19 - 20 L / h).

[0091] In another specific embodiment, the aeration of the wet premix can be achieved by using a rotating bar which is part of a rotary drum dryer, more specifically, a component of the supply trough where the wet premix is stored before being coated on the heated outer surface of the drum dryer and dried. The rotating bar is typically used to stir the wet premix during the waiting time before it is coated on the heated rotating drum of the drum dryer, in order to prevent phase separation or sedimentation in the supply trough. In the present invention, such a rotating bar is operated at a rotational speed in the range of about 150 to about 500 rpm, preferably about 200 to about 400 rpm, more preferably about 250 to about 350 rpm, so as to mix the wet premix at the air interface and provide sufficient mechanical agitation necessary to achieve the desired aeration of the wet premix.

[0092] As described above, the wet premix can be maintained at a high temperature during the aeration process to adjust the viscosity of the wet premix for optimized aeration and controlled drainage during drying. For example, when aeration is achieved by using the rotating bar of the rotary drum, the aerated wet premix in the supply trough is typically maintained at about 60 °C during the initial aeration by the rotating bar (while the rotary drum is stationary), and then heated to about 70 °C when the rotary drum is heated and starts to rotate.

[0093] The bubble size of the aerated wet premix helps to achieve a uniform layer within the OCF structure of the resulting solid sheet. In one embodiment, the bubble size of the aerated wet premix is about 5 to about 100 micrometers, and in another embodiment, the bubble size is about 20 micrometers to about 80 micrometers. Due to the uniformity of the bubble size, the resulting solid sheet has a consistent density.

[0094] After sufficient aeration, the aerated wet premix forms one or more sheets having opposing first and second faces. The sheet forming process can be carried out in any suitable manner, for example, by extrusion, casting, molding, vacuum forming, pressing, printing, coating, etc. More specifically, the aerated wet premix can be formed into a sheet by (i) casting it into a shallow cavity or tray or a specially designed sheet mold, (ii) extruding it onto a continuous belt or screen of a dryer, and (iii) coating it onto the outer surface of a rotary drum dryer. Preferably, the support surface on which the sheet is formed is made of or coated with a corrosion-resistant, non-interacting and / or non-sticky material such as metal (e.g., steel, chromium, etc.), TEFLON®, polycarbonate, NEOPRENE®, HDPE, LDPE, rubber, glass, etc.

[0095] Preferably, the formed sheet of the aerated wet premix has a thickness in the range of 0.5 mm to 4 mm, preferably 0.6 mm to 3.5 mm, more preferably 0.7 mm to 3 mm, even more preferably 0.8 mm to 2 mm, and most preferably 0.9 mm to 1.5 mm.

[0096] The drying of such formed sheets of the aerated wet premix is carried out in an anti-gravity manner by using either a conduction heating / drying configuration or a rotary drum heating / drying configuration.

[0097] Drum drying is particularly preferred as a continuous drying process suitable for large-scale drying. The heated rotatable cylinder used for drum drying is heated internally, for example, by steam or electricity, and rotated by an electric drive device attached to a base bracket at a predetermined rotational speed. The heated rotatable cylinder or drum preferably has an outer diameter in the range of about 0.5 meters to about 10 meters, preferably about 1 meter to about 5 meters, more preferably about 1.5 meters to about 2 meters. It may have a controlled surface temperature of about 80°C to about 170°C, preferably about 90°C to about 150°C, more preferably about 100°C to about 140°C. Further, such a heated rotatable cylinder rotates at a speed of about 0.005 rpm to about 0.25 rpm, preferably about 0.05 rpm to about 0.2 rpm, more preferably about 0.1 rpm to about 0.18 rpm.

[0098] This heated rotatable cylinder is preferably coated with a non-stick coating on its outer surface. The non-stick coating may overlap on the outer surface of the heated rotatable drum or may be fixed to the medium on the outer surface of the heated rotatable drum. Examples of the medium include, but are not limited to, heat-resistant non-woven fabric, heat-resistant carbon fiber, heat-resistant metal, or non-metal mesh. The non-stick coating can effectively maintain the structural integrity of the sheet-like article from damage during the sheet-forming process.

[0099] Also, a supply mechanism for adding the aerated wet premix of the raw materials as described above onto a heated rotatable drum is provided on the base bracket, whereby a thin layer of the viscous premix is formed on the outer surface of the heated rotatable drum. Thus, such a thin layer of the premix is dried via contact heating / drying by the heated rotatable drum. The supply mechanism includes a supply trough installed on the base bracket, while the supply trough has, thereon, at least one (preferably two) supply hoppers, an imaging device for dynamic observation of the supply, and an adjustment device for adjusting the position and tilt angle of the supply hoppers. By using the adjustment device to adjust the distance between the supply hopper and the outer surface of the heated rotatable drum, the need for different thicknesses of the formed sheet-like article can be satisfied. The adjustment device can also be used to adjust the supply hopper to different tilt angles so as to meet the material requirements of speed and quality. The supply trough may also include a rotating bar for agitating the wet premix therein in order to avoid phase separation and sedimentation before the wet premix is coated onto the outer surface of the heated rotatable drum. Such a rotating bar can also be used to aerate the wet premix as needed as described above.

[0100] Also, in order to prevent rapid heat loss, a heating shield attached to the base bracket may be present. The heating shield can also effectively save the energy required by the heated rotatable drum, thereby realizing a reduction in energy consumption and providing cost reduction. The heating shield is a modular assembly structure or an integrated structure and can be freely removed from the base bracket. The heating shield for sucking the hot steam is provided with a suction device in order to avoid any water condensate from falling onto the formed sheet-like article.

[0101] There may be an optional static scraping mechanism attached to the base bracket for scraping or scooping up a sheet-like article already formed by a heated rotatable drum. The static scraping mechanism can be installed on or on one side of the base bracket to convey the already formed sheet-like article downstream for further processing. The static scraping mechanism can move automatically or manually towards and away from the heated rotatable drum.

[0102] The process for producing the flexible porous soluble solid sheet of the present invention is as follows. First, a heated rotatable drum having a non-stick coating on the base bracket is driven by an electric drive device. Next, the adjusting device adjusts the supply mechanism so that the distance between the supply hopper and the outer surface of the heated rotatable drum becomes a preset value. On the other hand, the supply hopper adds a vented wet premix containing all or some of the raw materials for producing the flexible porous soluble solid sheet onto the outer surface of the heated rotatable drum, and forms a thin layer of the vented wet premix having a desired thickness thereon as described above in the previous section. Optionally, the suction device of the heating shield suctions the hot steam generated by the heated rotatable drum. Next, the static scraping mechanism scrapes up / scoops up the dried / solidified sheet formed by the thin layer of the vented wet premix after being dried at a relatively low temperature (e.g., 130 °C) by the heated rotatable drum. The dried / solidified sheet can also be peeled off manually or automatically without using such a static scraping mechanism and then wound up by a roller bar.

[0103] The total drying time in the present invention depends on the amount and solid content of the formulation in the wet premix, the drying temperature, the heat energy flow rate, and the thickness of the sheet material to be dried. Preferably, the drying time is about 1 minute to about 60 minutes, preferably about 2 minutes to about 30 minutes, more preferably about 2 to about 15 minutes, even more preferably about 2 to about 10 minutes, and most preferably about 2 to about 5 minutes.

[0104] During such drying time, the heating direction is arranged to be substantially opposite to the gravitational direction for more than half of the drying time, preferably more than 55% or 60% of the drying time (such as in the case of the rotary drum heating / drying configuration described above), more preferably more than 75% or even 100% of the drying time (such as in the case of the bottom conduction heating / drying configuration described above). Further, the aerated wet premix sheet can be dried for a first duration under a first heating direction and then dried for a second duration under a second opposite heating direction, the first heating direction being substantially opposite to the gravitational direction, and the first duration being any of 51% - 99% (such as 55%, 60%, 65%, 70% - 80%, 85%, 90%, or 95%) of the total drying time. Such a change in the heating direction can be easily achieved by, for example, a meandering elongated heating belt that can rotate along the longitudinal central axis, or by various other configurations not illustrated herein.

[0105] When the flexible soluble porous solid sheet is formed by the above-described process, multiple sheets can be stacked together and any coating composition can be applied to one or more of the solid sheets before forming the three-dimensional article of the present invention. The coating composition may contain a surfactant (a second surfactant) different from those contained in the sheet, together with a rheology modifier and optionally a solvent. The coating composition can serve to fill the flexible soluble porous article of the present invention with additional components including a fragrance and a surfactant for additional consumer benefits and improved performance. In a preferred embodiment of the present invention, the second surfactant may include a nonionic surfactant, more preferably a C6 - C 20 linear or branched alkylalkoxylated alcohol (AA), preferably having a weight average alkoxylation degree in the range of 7 - 9, of C 12 ~C 14 linear ethoxylated alcohol may be included. The coating composition has a viscosity of about 20 °C and 1 s -1When measured, it preferably has a viscosity of about 1 cps to about 25,000 cps, preferably about 2 cps to about 10,000 cps, more preferably about 3 cps to about 5,000 cps, and most preferably about 1,000 cps to about 5,000 cps. The viscosity value is measured using a Malvern Kinexus Lab+ rheometer (CP1 / 50 SR3468 SS) having a cone and plate geometry, at a gap width of 0.054 mm, a temperature of 20 °C, and a shear rate of 1.0 reciprocal seconds over 360 seconds.

[0106] When the coating composition is applied, a plurality of the above-described flexible soluble porous solid sheets can be stacked together to form a three-dimensional article according to the present invention. The three-dimensional article can be of any desired three-dimensional shape including, but not limited to, spherical, cubic, rectangular, elliptical, cylindrical, rod-shaped, sheet-shaped, flower-shaped, fan-shaped, star-shaped, disk-shaped, etc. The sheets can be combined and / or processed by any means known in the art, including, but not limited to, chemical means, mechanical means, and combinations thereof. Such combination processes and / or treatment processes are collectively referred to herein as "conversion" processes, i.e., they function to convert two or more flexible soluble porous sheets of the present invention into a single article.

[0107] The flexible soluble porous article of the present invention may include individual sheets of different colors visible from the outer surface (e.g., one or more sides) of such an article. Such visible sheets of different colors are aesthetically pleasing to the consumer. Further, the different colors of the individual sheets can provide a visual cue indicating different beneficial agents contained in the individual sheets. For example, a multi-layer soluble solid article may include a first sheet having a first color and containing a first beneficial agent and a second sheet having a second color and containing a second beneficial agent, where the first color provides a visual cue indicating the first beneficial agent and the second color provides a visual cue indicating the second beneficial agent.

[0108] Test method Test 1: Measurement of Compressive Force and Recovery Time Using a hollow circular hole punch with a diameter of 25 mm, a sample disk with a diameter of approximately 25 mm is cut from a flexible, soluble, porous article with a thickness of about 8 mm (measured using a vernier caliper). The article can include a stack of multiple flexible, soluble, porous sheets (e.g., those formed by the drum drying manufacturing process described above) to achieve the desired thickness. The sample disk is stored in an oven with temperature and humidity control capabilities at 25°C with an equilibrium humidity of 40% for a minimum duration of 4 hours.

[0109] The compressibility measurement is performed using a Haake MarsII rheometer having a PP60 mm plate-plate measurement geometry (model number 222-1271) and an MPC60 measurement plate (model number 222-1550) installed in a rheometer control unit. The base plate temperature of the rheometer is set and controlled at 25°C throughout the test. The rheometer is first calibrated using software to ensure that both the measurement distance 0 and the vertical force 0 are accurately set before starting the experiment.

[0110] Next, the compression test is conducted as follows. 1) Remove the 8-mm-thick sample disk from the oven and immediately place it at the center of the MPC60 measurement plate. Place a thin layer of parafilm on top of the stack to prevent the disk from sticking to the measurement geometry. 2) Lower the measurement geometry at a rate of 2.5 mm / min to 4 mm (i.e., the rheometer measurement position) as set by the rheometer software. The rheometer measurement position is set to approximately 50% of the original thickness of the sample disk, thereby achieving approximately 50% volume compression in the sample disk. 3) Once the measurement geometry reaches 4 mm, keep the state of the measurement geometry stationary for 5 minutes and record the pressure applied to it by the rheometer every second.

[0111] 4) After 5 minutes have elapsed, increase the measurement geometry and manually remove the sample disk. 5) Measure the thickness of the removed sample disk using a vernier caliper. This starts approximately 5 seconds after increasing the measurement geometry and is then performed every 30 seconds.

[0112] Next, the following parameters are calculated as follows.

[0113]

Number

[0114] It is recognized that the actual compressive force applied to the sample disk by the rheometer decreases with time within the 5-minute measurement period, and the average compressive force is calculated as follows.

[0115]

Number

[0116] Test 2: Continuous bubble content of the article Measure the continuous bubble content by the gas pycnometer method. The gas pycnometer method is a common analytical technique that uses a gas displacement method to accurately measure volume. An inert gas such as helium or nitrogen is used as the displacement medium. A sample of the flexible soluble porous article of the present invention is sealed within an instrument compartment of known volume, filled with an appropriate inert gas, and then expanded to another precise internal volume. Measure the pressure before and after expansion and use this to calculate the volume of the sample article.

[0117] ASTM standard test method D2856 provides procedures for determining the percentage of open cells using older models of air comparison pycnometers. This apparatus is no longer manufactured. However, by performing tests using the Micromeritics AccuPyc pycnometer, the percentage of open cells can be determined conveniently and precisely. ASTM procedure D2856 describes five methods (A, B, C, D, and E) for determining the open cell ratio of foamed materials. For these experiments, nitrogen gas is used and the Accupyc 1340 is used to analyze the samples with ASTM foampyc software. Method C of the ASTM procedure should be used to calculate the percentage of open cells. This method simply compares the geometric volume, determined using calipers and standard volume calculations, with the open cell volume measured by the Accupyc according to the following equation.

[0118] Percentage of open cells (%) = Open cell volume of sample / Geometric volume of sample * 100% These measurements are preferably performed by Micromeretics Analytical Services, Inc. (One Micromeritics Dr, Suite 200, Norcross, GA 30093). More information on this technique is available on the Micromeretics Analytical Services website (www.particletesting.com or www.micromeritics.com), or published in "Analytical Methods in Fine particle Technology" by Clyde Orr and Paul Webb.

[0119] Test 3: Micro-Computed Tomographic (μCT) method for determining the overall average pore diameter and average cell wall thickness of open cell foams (OCF) Porosity is the ratio of the total space occupied by the OCF of the void space. Porosity can be calculated from μCT scans by partitioning the void space by thresholding and determining the ratio of void voxels to all voxels. Similarly, the solid volume fraction (SVF) is the ratio of the total space of the solid space, and the SVF can be calculated as the ratio of the occupied voxels to all voxels. Both porosity and SVF are average scalar values that do not provide structural information such as the pore size distribution in the height direction of the OCF or the average bubble wall thickness of the OCF struts.

[0120] To characterize by the 3D structure of the OCF, a sample is imaged using a μCT X-ray scanner capable of acquiring a dataset with high isotropic spatial resolution. An example of a suitable measuring instrument is a SCANCO System model 50 μCT scanner (Scanco Medical AG, Bruttisellen, Switzerland) operating at the following settings: energy level of 45 kVp at 133 μA; 3000 projections; 15 mm field of view; 750 ms integration time; 5 times averaging; and a voxel size of 3 μm per pixel. After the scanning and subsequent data reconstruction are completed, the scanner system creates a 16-bit dataset called an ISQ file, where the gray level reflects the change in X-ray attenuation and thus is related to the material density. Then, the ISQ file is converted to 8 bits using a scaling factor.

[0121] The scanned OCF sample is usually prepared by drilling a core approximately 14 mm in diameter. The OCF punch is placed flat on the low-attenuation foam and then attached to a 15 mm diameter plastic cylindrical tube for scanning. A scan of the sample is acquired so that the entire volume of all the attached cut samples is included in the dataset. From this larger dataset, a smaller subvolume of the sample dataset is extracted from the total cross-section of the scanned OCF to create a 3D data slab, where the pores can be qualitatively evaluated without edge / boundary effects.

[0122] To characterize the pore size distribution in the height direction, the strut size, local thickness mapping algorithm, or LTM is implemented on the subvolume dataset. The LTM method starts with Euclidean Distance Mapping (EDM) and assigns gray level values equal to the distance from the closest boundary of each void voxel. Based on the EDM data, the 3D void space representing the pores (or the 3D solid space representing the struts) is mosaicked with spheres sized to match the EDM values. The voxels enclosed by the spheres are assigned the radius value of the largest sphere. In other words, each void voxel (or solid voxel of the strut) is assigned the radial value of the largest sphere that fits within both the void space boundary (or solid space boundary of the strut) and includes the assigned voxel.

[0123] The 3D labeled spherical distribution output from the LTM data scan is processed as a stack of two-dimensional images in the height direction (or Z direction) and can be used to estimate the change in spherical diameter from slice to slice as a function of the OCF depth. The thickness of the struts is processed as a 3D dataset, and the average value can be evaluated for the whole or part of the subvolume. The calculations and measurements were performed using AVIZO Lite (9.2.0) from Thermo Fisher Scientific and MATLAB (R2017a) from Mathworks.

[0124] Test 4: Thickness of the Flexible Soluble Porous Sheet The thickness of the flexible porous soluble sheet is obtained using a micrometer or thickness gauge such as the Mitutoyo Corporation Digital Disk Stand Micrometer Model Number IDS-1012E (Mitutoyo Corporation, 965 Corporate Blvd, Aurora, IL, USA 60504). The micrometer has a platen with a diameter of 1 inch and a weight of approximately 32 grams, and an approximate pressure of 0.09 psi (6.32 gm / cm 2Measure the thickness at the applied pressure of ().

[0125] Raise the platen, place a portion of the sheet article on the stand under the platen, carefully lower the platen to contact the sheet article, release the platen, and measure the thickness of the flexible porous soluble sheet by measuring the thickness in millimeters on a numerical display device. Except for the case of a non-flat and harder substrate, the sheet should be extended fully to all edges of the platen to ensure that the thickness is measured at the lowest possible surface pressure.

[0126] Test 5: Final moisture content of the article Obtain the final moisture content of the article of the present invention by using a Mettler Toledo HX204 Moisture Analyzer (S / N B706673091). Place at least 1 g of the dried sheet article on the measurement tray. Then, run the standard program with an additional program setting of an analysis time of 10 minutes and a temperature of 110 °C.

[0127] Test 6: Grammage of the article Calculate the grammage of the flexible porous soluble article of the present invention as the weight of the article per unit area (grams / m 2 ). The area is calculated as the projected area on a flat surface perpendicular to the outer edge of the article. Since the articles of the present invention are cut into 10 cm × 10 cm square samples, their areas are known. Then, weigh each such square sample, and then divide the obtained weight by the known area of 100 cm 2 to determine the corresponding grammage.

[0128] For an article of irregular shape, if it is a flat object, its area is calculated based on the area enclosed within the outer perimeter of such an object. Thus, for a spherical object, the area is 3.14 × (diameter / 2) based on the average diameter 2It is calculated as such. Therefore, for a cylindrical object, the area is calculated as diameter × length based on the average diameter and the average length. For a three-dimensional object with an irregular shape, the area is calculated based on the side with the maximum outer dimension projected onto a flat surface oriented perpendicular to this side. This can be achieved by carefully tracing the outer dimensions of the object with a pencil on a single sheet of graph paper, then approximately counting the squares and multiplying by the known area of the square, or by taking a photograph of the traced area (shaded for contrast) including a scale and calculating the area using image analysis techniques.

[0129] Test 7: Density of the article The density of the flexible porous soluble article of the present invention is determined by the following equation. Calculated density = basis weight of the porous solid / (thickness of the porous solid × 1,000). The basis weight and thickness of the article are determined according to the methods described herein.

[0130] Test 8: Specific surface area of the article The specific surface area of a flexible porous soluble article is measured by gas adsorption technology. The surface area is a measure of the exposed surface of a solid sample at the molecular scale. The BET (Brunauer, Emmet, and Teller) theory is the most well-known model used to determine surface area and is based on gas adsorption isotherms. Gas adsorption measures gas adsorption isotherms using physical adsorption and capillary condensation. This technique is summarized by the following steps. The sample is placed in a sample tube and heated under vacuum or under a gas flow to remove contaminants on the surface of the sample. The sample weight is obtained by subtracting the weight of the empty sample tube from the combined weight of the degassed sample and the sample tube. Next, the sample tube is placed on the analysis port and the analysis is started. The first step in this analysis process is to evacuate the sample tube and then measure the free space volume inside the sample tube using helium gas at liquid nitrogen temperature. Next, the sample is evacuated again to remove the helium gas. The instrument then begins to collect the adsorption isotherm by dosing krypton gas at intervals specified by the user until the required pressure measurement is achieved. Next, the sample may be analyzed using an ASAP 2420 equipped with krypton gas adsorption. These measurements are preferably performed by Micromeretics Analytical Services, Inc. (One Micromeritics Dr, Suite 200, Norcross, GA 30093). More information on this technique is available on the Micromeretics Analytical Services website (www.particletesting.com or www.micromeritics.com) or is published in the book "Analytical Methods in Fine particle Technology" by Clyde Orr and Paul Webb.

Example

[0131] Example 1: Comparative test showing different 50% compression forces and 90% recovery times demonstrated by different flexible soluble porous articles Three examples (A)-(C) of the flexible, water-soluble, porous article having high compressibility and resilience according to the present invention are provided, along with two comparative examples (1)-(2) of the article.

[0132] Examples (A)-(C) and comparative examples (1)-(2) of the present invention were made by stacking multiple layers of a flexible, water-soluble, porous solid sheet made by the drum drying process as described above, using the following wet (before drying) formulations and dry (after drying) formulations.

[0133] [Table 1]

[0134] [Table 2]

[0135] For examples (A)-(C) and comparative examples (1)-(2) of the present invention, the 50% compression force and recovery time were measured as described in Test 1 above. The test results are as follows.

[0136] [Table 3] * Due to the maximum force limit of the rheometer, it was not possible to compress sufficiently to reach 50% volume compression. Only about 43% maximum volume compression could be achieved. ** The time required for the compressed sample to recover to 90% of its original thickness / volume.

[0137] The above examples show significant differences between the flexible, water-soluble, porous articles in terms of their respective 50% compression forces and 90% recovery times. Therefore, for example, in order to handle / operate through compression and decompression by applying a moderate force under normal manufacturing / transportation / storage conditions, it is desirable to select the more compressible and more resilient articles (e.g., examples of the present invention) according to the present invention.

[0138] The dimensions and values disclosed in this specification should not be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and the functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

[0139] All documents cited in this specification, including any patents or patent applications that are cross-referenced or related, and any patent application or patent for which this application claims priority or the benefit thereof, are hereby incorporated by reference in their entirety to the extent not explicitly excluded or limited. The citation of any document is not to be construed as an admission that it is prior art with respect to any invention disclosed or claimed in this specification, or that it alone or in any combination with any other reference(s) teaches, suggests, or discloses any such invention. Further, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition given to the term in this document shall apply.

[0140] While specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, all such changes and modifications within the scope of the invention are intended to be covered by the appended claims.

Claims

Claim 1 A method of handling or operating a flexible, water-soluble, porous article, comprising: d) providing a flexible, soluble, porous article comprising a water-soluble polymer and a surfactant, said flexible, soluble, porous article being characterized by (1) a compressive force of less than 20,000 N / m ２ when measured at 40% equilibrium humidity at 25° C. and (2) a 90% recovery time of less than 5 minutes; e) applying a force in the range of 500 N / m ２ to 100,000 N / m ２ to the flexible soluble porous article at a temperature in the range of 20 °C to 40 °C and an equilibrium humidity in the range of 20% to 95% so as to achieve a volume compression of 50% or more; f) removing the force from the compressed flexible, water-soluble, porous article such that at least 80% volume recovery is achieved in less than 10 minutes. Claim 2 The method of claim 1, wherein the force applied in step (b) is selected from the group consisting of pressure, vacuum, suction, torque, and combinations thereof. Claim 3 The method of claim 1 or 2, wherein the flexible, water-soluble, porous article is characterized by a continuous bubble content of 80% to 99%, preferably 85% to 99%, more preferably 90% to 99%, and an overall average pore size of 100 μm to 2000 μm, preferably 150 μm to 1000 μm, more preferably 200 μm to 600 μm. Claim 4 The method of any one of claims 1 to 3, wherein the flexible, water-soluble, porous article is characterized by a maximum dimension D and a minimum dimension z, and the ratio D / z ranges from 1 to 10, preferably 1.4 to 9, more preferably 1.5 to 8, and most preferably 2 to 7. Claim 5 The method of any one of claims 1 to 4, wherein the flexible, water-soluble, porous article comprises a plurality of flexible, water-soluble, porous sheets, each of the plurality of flexible, water-soluble, porous sheets having a thickness in the range of 0.5 mm to 4 mm, preferably 0.6 mm to 3.5 mm, more preferably 0.7 mm to 3 mm, even more preferably 0.8 mm to 2 mm, and most preferably 1 mm to 1.5 mm, and the article comprises 4 to 50, preferably 5 to 40, more preferably 6 to 30 of the flexible, water-soluble, porous sheets. Claim 6 The flexible soluble porous article contains 5% to 50%, preferably 8% to 40%, more preferably 10% to 30%, and most preferably 11% to 25% of the water-soluble polymer based on the total weight of the article. Preferably, the water-soluble polymer has a weight average molecular weight of 50,000 to 400,000 Daltons, preferably 60,000 to 300,000 Daltons, more preferably 70,000 to 200,000 Daltons, and most preferably 80,000 to 150,000 Daltons. More preferably, the water-soluble polymer is polyvinyl alcohol characterized by a degree of hydrolysis in the range of 40% to 100%, preferably 50% to 95%, more preferably 65% to 92%, and most preferably 70% to 90%. The method according to any one of claims 1 to 5.

7. The flexible soluble porous article contains 30% to 90%, preferably 40% to 80%, more preferably 50% to 70% of the surfactant based on the total weight of the article. Preferably, the surfactant is selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, polymeric surfactants, and any combination thereof. The method according to any one of claims 1 to 6.

8. In step (b), the force applied is a vacuum force, and the flexible soluble porous article is placed in a fluid-impermeable package before the vacuum force is applied. The fluid-impermeable package is sealed after 50% or more of the volume compression is achieved. The method according to any one of claims 1 to 7.

9. In step (c), the removal of the vacuum force from the compressed flexible soluble porous article requires breaking the seal of the fluid-impermeable package. The method according to claim 8.

10. A method of packaging a flexible soluble porous article, a) providing a flexible, soluble, porous article comprising a water-soluble polymer and a surfactant, said flexible, soluble, porous article being characterized by a compressive force of less than 100,000 N / m when measured at 25 °C and 40% equilibrium humidity ２ and a process characterized by a compressive force of less than 50% b) placing one or more of the flexible soluble porous articles in a fluid-impermeable package; c) applying a vacuum force to the flexible soluble porous article to achieve a volume compression of 20% or more; d) sealing the fluid-impermeable package having the compressed flexible soluble porous article therein. A method comprising:

11. The flexible, water-soluble, porous article is characterized by a continuous bubble content of 80% to 99%, preferably 85% to 99%, more preferably 90% to 99%, and an overall average pore diameter of 100 μm to 2000 μm, preferably 150 μm to 1000 μm, more preferably 200 μm to 600 μm, according to the method of claim 10.

12. The flexible, water-soluble, porous article is characterized by a maximum dimension D and a minimum dimension z, and the ratio of D / z is in the range of 1 to 10, preferably 1.4 to 9, more preferably 1.5 to 8, and most preferably 2 to 7, according to the method of claim 10 or 11.

13. The flexible, water-soluble, porous article includes a plurality of flexible, water-soluble, porous sheets, each of the plurality of flexible, water-soluble, porous sheets having a thickness in the range of 0.5 mm to 4 mm, preferably 0.6 mm to 3.5 mm, more preferably 0.7 mm to 3 mm, even more preferably 0.8 mm to 2 mm, and most preferably 1 mm to 1.5 mm, and the article preferably includes 4 to 50, preferably 5 to 40, more preferably 6 to 30 of the flexible, water-soluble, porous sheets, according to the method of any one of claims 10 to 12.

14. The flexible, water-soluble, porous article includes 5% to 50%, preferably 8% to 40%, more preferably 10% to 30%, and most preferably 11% to 25% of the water-soluble polymer based on the total weight of the article, and preferably, the water-soluble polymer is polyvinyl alcohol characterized by a weight average molecular weight in the range of 50,000 to 400,000 daltons, preferably 60,000 to 300,000 daltons, more preferably 70,000 to 200,000 daltons, and most preferably 80,000 to 150,000 daltons, and more preferably, the water-soluble polymer is characterized by a degree of hydrolysis in the range of 40% to 100%, preferably 50% to 95%, more preferably 65% to 92%, and most preferably 70% to 90%, according to the method of any one of claims 10 to 13.

15. The flexible water-soluble porous article contains 30% to 90%, preferably 40% to 80%, more preferably 50% to 70% of the surfactant based on the total weight of the article. Preferably, the surfactant is selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, polymeric surfactants, and any combination thereof. The method according to any one of claims 10 to 14.

16. A compressed flexible water-soluble porous article containing a water-soluble polymer and a surfactant, wherein the compressed article is characterized by a volume recovery of 20% or more within less than 10 minutes under reduced pressure. A compressed flexible water-soluble porous article.

17. The compressed article is disposed within a sealed fluid-impermeable package, and the reduced pressure is achieved by opening the sealed fluid-impermeable package. The compressed flexible water-soluble porous article according to claim 16.

18. The article is characterized by a continuous bubble content of 80% to 99%, preferably 85% to 99%, more preferably 90% to 99%, and an overall average pore diameter of 100 μm to 2000 μm, preferably 150 μm to 1000 μm, more preferably 200 μm to 600 μm. The compressed flexible water-soluble porous article according to claim 16 or 17.

19. The article is characterized by a maximum dimension D and a minimum dimension z, and the ratio of D / z ranges from 1 to 10, preferably 1.4 to 9, more preferably 1.5 to 8, and most preferably 2 to 7. The compressed flexible water-soluble porous article according to any one of claims 16 to 18.

20. The flexible water-soluble porous article includes a plurality of flexible water-soluble porous sheets. Each of the plurality of flexible water-soluble porous sheets has a thickness in the range of 0.5 mm to 4 mm, preferably 0.6 mm to 3.5 mm, more preferably 0.7 mm to 3 mm, even more preferably 0.8 mm to 2 mm, and most preferably 1 mm to 1.5 mm. The article preferably includes 4 to 50, preferably 5 to 40, more preferably 6 to 30 of the flexible water-soluble porous sheets. The compressed flexible water-soluble porous article according to any one of claims 16 to 19.

21. The flexible soluble porous article contains 5% to 50%, preferably 8% to 40%, more preferably 10% to 30%, and most preferably 11% to 25% of the water-soluble polymer based on the total weight of the article. Preferably, the water-soluble polymer has a weight average molecular weight of 50,000 to 400,000 daltons, preferably 60,000 to 300,000 daltons, more preferably 70,000 to 200,000 daltons, and most preferably 80,000 to 150,000 daltons. More preferably, the water-soluble polymer is polyvinyl alcohol characterized by a degree of hydrolysis in the range of 40% to 100%, preferably 50% to 95%, more preferably 65% to 92%, and most preferably 70% to 90%. The compressed flexible soluble porous article according to any one of claims 16 to 20.

22. The flexible soluble porous article contains 30% to 90%, preferably 40% to 80%, more preferably 50% to 70% of the surfactant based on the total weight of the article. Preferably, the surfactant is selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants, polymeric surfactants, and any combination thereof. The compressed flexible soluble porous article according to any one of claims 16 to 21.

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