Absorbent article comprising water-responsive film and method of producing same

Abstract

The present disclosure relates to an absorbent article comprising a water-responsive film. The film includes a crystalline water dispersible polymer and an aromatic thermoplastic polyurethane elastomeric polymer. The film has a crystallinity of at least 25% and at most 60%. The film can include one or more pores that, when used in an absorbent article, can transition between open and closed configurations in response to water, thereby affecting absorption and rewetting properties. The film expands upon contact with water, but shrinks upon drying, allowing multiple fouling to trigger the expansion and shrinkage characteristics of the film.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 400,645, filed on August 24, 2022, which is hereby incorporated by reference in its entirety for all intents and purposes. Technical Field

[0003] The present disclosure relates generally to absorbent articles. More specifically, the present disclosure relates to absorbent articles including water-responsive films that swell upon contact with water (e.g., water from body fluids) to close one or more pores that initially facilitate the passage of fluid. Background Art

[0004] Absorbent articles such as diapers, incontinence garments, sanitary napkins and catamenial pads are designed to absorb and retain liquids and other excreta from the human body to prevent soiling of the body and clothing. These products absorb and contain fluids (e.g., body excreta) and are discarded after a limited use time. Conventional absorbent articles include an absorbent body disposed between an inner layer adapted to contact the wearer's skin and allow fluid to enter the absorbent body and an outer layer for preventing the absorbed liquid from leaking out of the article. The inner layer of the absorbent article is generally liquid permeable to allow body waste to pass through the inner layer to be absorbed by the absorbent body.

[0005] Many absorbent articles that collect fluid are commercially available. However, these absorbent articles have a tendency to leak before the fluid absorption capacity is completely exhausted. For example, the absorbent structure of the absorbent article may have a fluid intake rate determined by the structure and materials of the absorbent structure. If the fluid flow to the absorbent structure exceeds the fluid absorption rate, the fluid may leak onto the surface of the absorbent article. This may result in direct contact between the fluid and the user's skin, thereby causing the skin to become overhydrated, making it susceptible to irritation and infection.

[0006] In addition, absorbent articles should provide a fast passage for fluid (such as urine or menstruation) to enter the absorbent structure of the absorbent article, and the fluid should be retained therein. If the fluid is not fully retained in the absorbent structure of the absorbent article, the pressure applied to the absorbent article will cause the fluid to pass through the surface of the absorbent article from the inside of the absorbent article. In order to provide fast fluid intake, the material constituting the absorbent structure of the absorbent article needs to have sufficient permeability and wettability to facilitate the intake of the fluid. Although these characteristics of absorbent articles provide fast fluid intake, they also allow easy backflow, that is, when pressure is applied to the absorbent article, the fluid flows out of the absorbent article and flows onto the user's skin. As a result, in conventional absorbent articles, there is a correlation between the fluid intake rate and the backflow rate and the backflow volume, resulting in the so-called "easy in and easy out" phenomenon. Therefore, absorbent articles that can quickly inhale fluids usually have greater fluid backflow, resulting in a higher level of skin overhydration. On the contrary, absorbent articles that show limited fluid backflow and therefore less leakage tend to have slow fluid intake and therefore more leakage.

[0007] In addition to leakage problems with some absorbent articles, there are also hygiene issues that directly affect the user. Body fluids that leak onto the surface of absorbent articles often come into direct contact with the user, which creates an unpleasant and unclean feeling. Especially for feminine hygiene products (such as sanitary napkins), the unpleasant or unclean feeling may lead to a poor perception of product performance and failure to maximize the use of the product.

[0008] There remains a need for an absorbent article that substantially reduces the incidence of fluid leakage from the absorbent article while supporting rapid fluid intake. Summary of the invention

[0009] The covered embodiments of the present disclosure are defined by the claims rather than by this summary. This summary is a high-level overview of various aspects of the invention and introduces some concepts that are further described in the detailed description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all of the drawings, and each claim.

[0010] In some embodiments, the present disclosure relates to an absorbent article. The absorbent article includes: a film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%, wherein the film is configured to expand when in contact with a fluid. In some embodiments, the water-soluble polymer includes polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelling starch, nylon copolymer, polyacrylic acid or a combination thereof. In some embodiments, the film includes a patterned surface with one or more holes, wherein the hole accounts for at least 10% of the total surface area of ​​the film. In some embodiments, the area adjacent to one or more holes is treated with a hydrophilic agent. In some embodiments, a portion of the film is bonded to a substrate. In some embodiments, the area of ​​the film adjacent to one or more holes is not bonded to a substrate. In some embodiments, the aromatic thermoplastic polyurethane includes a polyester-based thermoplastic polyurethane. In some embodiments, the film has a crystallinity of 25% to 60%. In some embodiments, the film includes a water-soluble polymer in an amount of 10% to 90% by weight based on the total weight of the film. In some embodiments, the film comprises an aromatic thermoplastic polyurethane in an amount of 10% to 90% by weight based on the total weight of the film. In some embodiments, the weight ratio of the water-soluble polymer to the aromatic thermoplastic polyurethane is at least 1: 1. In some embodiments, the film comprises a water-soluble polymer in an amount of 30% to 70% by weight based on the total weight of the film, a thermoplastic polyurethane in an amount of 30% to 60% by weight based on the total weight of the film, and the ratio of the water-soluble polymer to the aromatic thermoplastic polyurethane is at least 1.5: 1. In some embodiments, the film comprises one or more additives, and the one or more additives include surfactants, absorbents, antibiotics or skin benefit agents. In some embodiments, the one or more additives include superabsorbents. In some embodiments, the absorbent article includes a fluid transfer layer between the film and the absorbing body. In some embodiments, the film also includes a 3-D structure treated with a hydrophobic agent.

[0011] In some embodiments, the present disclosure provides an absorbent article comprising: a film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%; a substrate bonded to the film to produce a laminate; a backing sheet; and an absorbent body between the laminate and the backing sheet.

[0012] In some embodiments, the present disclosure provides a method for producing a laminate. The method includes providing a film, wherein the film comprises a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than 25%; and bonding a portion of the film to a substrate to produce a laminate. In some embodiments, the method includes cutting or scoring a pattern in a laminate comprising a plurality of holes. In some embodiments, the film is configured to expand when in contact with body fluids. In some embodiments, an area of ​​the film adjacent to the hole is not bonded to the substrate.

[0013] Further aspects, objects and advantages will become apparent upon consideration of the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of multiple layers of a portion of an absorbent article according to some embodiments of the present invention.

[0015] Figure 2 is a schematic diagram of a water-responsive membrane including a star-shaped pore / valve pattern when the water-responsive membrane transitions between a contracted state and an expanded state according to some embodiments of the present invention.

[0016] Figure 3 is a schematic diagram of a water-responsive membrane including a bull's-eye shaped hole / valve pattern when the water-responsive membrane transitions between a contracted state and an expanded state according to some embodiments of the present invention.

[0017] 4A to 4F is a schematic diagram of an exemplary pore / valve design for a water-responsive membrane according to some embodiments of the present invention.

[0018] Figure 5 is a cross-sectional view of a portion of an absorbent article according to some embodiments of the present invention.

[0019] Figure 6 is a cross-sectional view of a portion of an absorbent article according to some embodiments of the present invention.

[0020] Fig. 7A is a flow chart of a method of producing a laminate according to some embodiments of the present invention.

[0021] Figure 7B is a schematic diagram of an exemplary laminate including a substrate bonded to a portion of a water-responsive membrane according to some embodiments of the present invention.

[0022] Fig. 8A and Figure 8B is a photograph of an exemplary absorbent article including a water-responsive film in a contracted state ( Fig. 8A ) and in an expanded state ( Figure 8B ) bullseye pattern. DETAILED DESCRIPTION

[0023] introduce

[0024] The present disclosure relates to absorbent articles including a water-responsive film (e.g., a top sheet including the film), which allows rapid fluid inhalation and limits fluid reflux. In addition to the water-responsive film, the absorbent article may include a backsheet, and an absorbent body inserted between the film and the backsheet. The water-responsive film, the backsheet, and the absorbent body each have a wearer-facing surface and a clothing-facing surface. In some embodiments, a substrate is bonded to the wearer-facing surface of the water-responsive film to produce a laminate that forms the outermost surface of the absorbent article in contact with the user's skin. The water-responsive film may include one or more layers in the liquid deposition area of ​​the absorbent article.

[0025] The water-responsive membrane described herein may include one or more holes that can be used as a water-responsive one-way valve to allow fluid to flow to other parts of the absorbent article (e.g., the absorbent body). The membrane is elastic and water-sensitive so that the membrane expands when in contact with a fluid (e.g., urine, menstruation, or other body fluids). When not expanded, the membrane allows fluid to quickly pass through the holes of the membrane and optionally enter another layer of the absorbent article (e.g., the absorbent body of the absorbent article). When the fluid flows through the holes of the membrane, the membrane also absorbs some fluid, and the membrane expands. The expansion of the membrane closes the holes that initially facilitate the rapid passage of the fluid. The closed holes prevent further fluid reflux from flowing through the membrane. Once the membrane is dry (i.e., fluid desorption), the membrane shrinks, opens the holes, and the membrane can allow additional fluid to pass.

[0026] The water-responsive membrane comprises a water-soluble polymer and an elastomeric thermoplastic polyurethane (TPU). In particular, the water-responsive membrane comprises a blend of two polymers: (1) a water-soluble polymer having a substantially crystalline morphology; and (2) an aromatic TPU. The dual properties of elasticity and water-responsiveness are achieved by blending a synergistic combination of a water-soluble polymer and an aromatic TPU to produce a membrane having a crystallinity of at least 25%. It has been found that the combination of an aromatic TPU having suitable strength and tensile modulus with a water-soluble polymer having suitable crystallinity produces a membrane that swells upon contact with a fluid, which then shrinks toward its original size upon drying or desorption.

[0027] Absorbent articles including water-responsive membranes avoid the traditional correlation between fluid intake rate and backflow volume, and provide rapid fluid intake and limited fluid backflow. This benefit comes from the ability of the membrane to expand when in contact with the fluid. In the expanded state, the water-responsive membrane can prevent the flow of fluid through the membrane, including the backflow of the fluid. Due to the water-responsive expansion and contraction characteristics of the membrane, the mechanism for converting the valve from an open first state to a closed second state does not require any action or input other than the fluid itself, that is, the valve automatically opens or closes to allow or prevent fluid from passing. The state of the valve is determined by the amount of fluid in contact with the membrane. In this way, the valve can alternate between a first state (e.g., a contracted size, an open hole) and a second state (an expanded size, a closed hole) for rapid passage of the fluid while preventing backflow.

[0028] In some embodiments, the water-responsive film can be bonded to a substrate (e.g., nonwoven) to form a laminate. The substrate can control the expansion and contraction of the water-responsive film. The substrate can be bonded to the wearer-facing surface or the clothing-facing surface of the water-responsive film. In some embodiments, the substrate is bonded to the wearer-facing surface of the water-responsive film in contact with the user's skin. The laminate can be scored or cut into a pattern including one or more holes. For example, the laminate can be laser cut or punched to provide one or more holes with various geometric shapes (e.g., circular, star-shaped, rectangular, square). In this way, the film of the laminate can be used as a water-responsive one-way valve to regulate the fluid flowing to the absorbent body. The hole of the water-responsive film can be positioned in the liquid deposition area of ​​the absorbent article. When the absorbent article is in contact with the fluid, the expansion of the film material around or adjacent to the hole causes the hole to close. After the fluid is dried or desorbed, the water-responsive film shrinks to its original size (or substantially original size), thereby opening the hole for additional fluid flow.

[0029] The water-responsive film facilitates good liquid retention to keep the surface dry, thereby keeping the wearer's skin dry. In some embodiments, the backsheet is liquid-impermeable and prevents any fluid from the absorbent body from leaking through the absorbent article. In some embodiments, the individual elements can be bonded to each other to produce an absorbent article with the desired comfort and performance levels.

[0030] definition

[0031] As used herein, the terms "invention," "the invention," "this invention," and "the present invention" are intended to refer broadly to all subject matter of this patent application and the claims that follow. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims that follow.

[0032] As used herein, the meaning of “a / an” or “the” includes both the singular and the plural, unless the context clearly indicates otherwise.

[0033] As used herein, the term "bonded" refers herein to the joining, adhering, connecting, attaching, etc. of two elements. Two elements will be considered to be bonded together when they are joined, adhered, connected, attached, etc. directly to each other or indirectly to each other, such as when each element is directly bonded to an intermediate element. The bonding of one element to another element can be performed by continuous or intermittent bonding.

[0034] As used herein, the term "liquid impermeable" refers to a layer or layers of laminates wherein under normal use conditions, liquid body exudates (such as urine) do not penetrate through the layer or layers.

[0035] As used herein, the term "liquid permeable" refers to any material that is not impermeable to liquids.

[0036] As used herein, the term "superabsorbent" refers herein to a water-swellable, water-insoluble organic or inorganic material that is capable of absorbing at least about 10 times its weight, and in some embodiments at least about 30 times its weight, in an aqueous solution containing 0.9% by weight sodium chloride under most favorable conditions. Superabsorbent materials can be natural, synthetic, and modified natural polymers and materials. Additionally, superabsorbent materials can be inorganic materials such as silica gel or organic compounds such as cross-linked polymers.

[0037] As used herein, the term "thermoplastic" refers herein to a material that is softenable and shapeable when exposed to heat and substantially returns to a non-softened state when cooled.

[0038] As used herein, "wearer-facing surface" refers to the surface of an article that faces in the direction of the individual wearing the article.

[0039] As used herein, "garment-facing surface" refers to the surface of an article that faces the direction of clothing in which the article is worn (ie, generally on the top of the article).

[0040] As used herein, a "liquid deposition area" of an article refers to the area of ​​the article where liquid is primarily deposited during typical use.

[0041] As used herein, the term "machine direction" or "MD" generally refers to the direction in which a material is produced. The term "cross direction" or "CD" refers to the direction perpendicular to the machine direction. The dimension measured in the cross direction is called the "width" dimension, while the dimension measured in the machine direction is called the "length" dimension.

[0042] As used herein, the terms "elastomeric" and "elastic" refer to a material that can stretch in at least one direction (such as the CD direction) upon application of a stretching force and contract / return to approximately its original dimensions upon release of the stretching force. For example, a stretched material may have a stretched length that is at least 50% greater than its relaxed, unstretched length and will return to within at least 50% of its stretched length upon release of the stretching force. A hypothetical example would be a one (1) inch sample of material that can be stretched to at least 1.50 inches and will return to a length of at least 1.25 inches upon release of the stretching force. Advantageously, the material contracts or recovers at least 50% of the stretched length, and even more advantageously at least 80%.

[0043] As used herein, the term "extensible" or "extensibility" generally refers to a material that stretches or extends at least about 50% of its relaxed length or width in the direction of an applied force. An extensible material does not necessarily have recovery. For example, an elastomeric material is an extensible material with recovery. A film may be extensible but have recovery and therefore are not an extensible non-elastic material.

[0044] All ranges disclosed herein should be understood to include any and all subranges contained therein. For example, the specified range "1 to 10" should be considered to include any and all subranges (including end values) between a minimum value of 1 and a maximum value of 10; that is, all subranges start with a minimum value of 1 or greater, such as 1 to 6.1, and end with a maximum value of 10 or less, such as 5.5 to 10.

[0045] Absorbent products

[0046] The present disclosure relates to absorbent articles. For example, the absorbent articles can be personal care products. The personal care products of the present disclosure include, but are not limited to: feminine hygiene products, such as sanitary wipes and menstrual absorbent devices (e.g., sanitary napkins and sanitary napkins); infant and child care products, such as disposable diapers, absorbent underpants and training pants; wound dressings, such as bandages; incontinence products; products for wiping and absorbing oils, and the like. Suitable absorbent articles are described in more detail in U.S. Patent No. 7,632,258.

[0047] Figure 1 is a schematic diagram of a portion of an absorbent article according to some embodiments of the present invention. The absorbent article 100 includes a plurality of layers that may be bonded to another layer (eg, an adjacent layer or a non-adjacent layer). Figure 1The absorbent article 100 shown in the figure includes a laminate 105, which includes a water-responsive film 110, a backsheet 130, and an absorbent body 120 positioned between the film 110 and the backsheet 130. Each of the film 110, the absorbent body 120, and the backsheet 130 includes a wearer-facing side and a garment-facing side. For example, the top surface of the film 110 is the wearer-facing surface 112, and the bottom surface of the film 110 is the garment-facing surface 114. Figure 1 As shown in the figure, the wearer-facing surface is the top surface of the film 110, the absorbent body 120 and the backsheet 130, and the backsheet 130 is arranged toward the wearer's body or placed adjacent to the wearer's body during normal use. The garment-facing surface is the bottom surface of the film 110, the absorbent body 120 and the backsheet 130, and the backsheet 130 is arranged away from the wearer's body and faces the direction of the garment worn on the absorbent article during normal use.

[0048] exist Figure 1 100. In some embodiments, the garment-facing surface 114 of the film 110 may be directly adjacent to the wearer-facing side 122 of the absorbent body 120. The garment-facing side 124 of the absorbent body 120 may be directly adjacent to or close to the wearer-facing side 132 of the backsheet 130. In some embodiments, the wearer-facing surface 112 of the film 110 is the outermost surface of the absorbent article 100 that is in direct contact with the user. In some embodiments, the garment-facing surface 134 of the backsheet 130 is the outermost surface of the absorbent article 100 and may directly contact clothing worn on the absorbent article. The film 110 allows fluid to flow to the absorbent body 120, and the backsheet 130 may be substantially impermeable to the fluid.

[0049] In some embodiments, the absorbent article 100 may further include one or more additional layers 140, such as Figure 1 . The additional layer 140 may be a liquid intake layer, a surge layer, a liquid wicking layer, a liquid distribution layer, a transfer layer, a barrier layer, etc., and multiple layers and combinations thereof. In some embodiments, the additional layer 140 is disposed between the absorbent body 120 and the backing film 130. The additional layer 140 may be disposed at any position between each of the films 110, the absorbent body 120, and the backing film 130. For example, the absorbent article 100 may include a fluid transfer layer between the laminate 105 and the absorbent body 120. In addition or alternatively, the absorbent article may include one or more additional layers (not shown) between the wearer-facing surface 112 of the film 110 and the outermost surface of the absorbent article 100.

[0050] exist Figure 1In the embodiment of the present invention, the laminate 105 is the top sheet or body side liner of the absorbent article 100. The laminate 105 includes a substrate 106 bonded to a film 110. The film 110 is bonded to the substrate 106 to control the expansion direction of the film. In some embodiments, the surface of the film 110 facing the wearer is bonded to the substrate 106 to form the laminate 105. For example, the laminate 105 may include a surface 112 facing the wearer of the nonwoven material bonded to the film 110 as the substrate 106. In some embodiments, the nonwoven material may be in direct contact with the user's skin. In other embodiments, the laminate 105 may be located deeper in the absorbent article 100 alone. In some embodiments, the film 110 may be located deeper in the absorbent article alone and may be bonded to another layer (e.g., an absorbent body). In some embodiments, the film 110 may be arranged in any layer of the absorbent article 100 facing the wearer relative to the absorbent body 120.

[0051] The laminate 105 can be scored or cut to include a pattern. For example, the laminate 105 can be laser cut or punched to provide one or more holes 150 having various geometric shapes (e.g., circular, star-shaped, rectangular, square). In this way, the laminate 105 can be used as a water-responsive one-way valve for fluid flow to the absorbent body 120. The holes 150 of the laminate 105 can be positioned in a liquid deposition area (not shown) of the absorbent article 100. Due to the expansion properties of the film 110, when the absorbent article 100 is in contact with the fluid, the material of the film 110 surrounding or adjacent to the plurality of holes 150 can begin to expand and close the holes 150. The film 110 enables the absorbent article to regulate the fluid flowing to the absorbent body 120. After the fluid is absorbed by the absorbent body 120 and desorbed from the film 110 (so the film is dry), the film 110 can shrink to its original size (or substantially original size) to open the holes 150 for additional fluid flow.

[0052] In some embodiments, the film 110 is bonded to at least one substrate 106 to produce a laminate 105. For example, the film 110 can be adhesively bonded to at least one substrate 106. The film 110 can be bonded to at least one substrate 106 (top and / or bottom) to control the lateral expansion in the area directly surrounding the hole 150, thereby facilitating the closure of the hole 150 used as a valve. This can be achieved by patterning the laminate 105 to leave a specific unbonded area near one or more holes 150 of the film 110. The lateral expansion of the unbonded portion of the film 110 allows the hole 150 to close when contacting water. The amount of expansion (e.g., lateral expansion) may be affected by the composition of the film 110, the ratio of the water-soluble polymer to the thermoplastic polyurethane, and the amount of fluid contacting the laminate 105.

[0053] In some embodiments, a part of film 110 of the present disclosure can be processed with hydrophobic agent or super hydrophobic agent, which helps to prevent fluid from staying on the top of the surface 112 facing the wearer and prevents from leaving unpleasant and / or unclean feeling due to stains on the surface, debris or moisture accumulated. For example, the region of the non-adjacent hole 150 of film 110 can be processed with hydrophobic agent. The part of the film 110 processed with hydrophobic agent can be pooled in the hole 150 of film 110. When film 110 is processed with hydrophobic agent or super hydrophobic agent, hole 150 guarantees that fluid penetrates through the hole opened. In some embodiments, hydrophobic agent, super hydrophobic agent or hydrophilic agent can be applied to the base material (for example, laminate or liner) bonded to film 110.

[0054] In some embodiments, the area of ​​the film 110 adjacent to the hole 150 can be treated with a hydrophilic treatment agent. The treatment agent can increase the surface energy in and around the hole 150 to preferentially guide the fluid flow into the hole 150 to provide the advantages of the present disclosure in preventing stains, rewetting, accumulation of particulate debris on the wearer-facing surface 112, and other unpleasant aspects. In some embodiments, the film 110 is bonded to a substantially hydrophobic nonwoven material. For example, the film 110 can be bonded to spunbond, spunbond-meltblown-spunbond (SMS), bonded carded web (BCW), hydroentangled, or coform.

[0055] In some embodiments, the surface of film 110 may include a three-dimensional profile. For example, film 110 may include a 3-D material with an optimized hole, and a combination of hydrophilic and hydrophobic treatments strategically applied to the material to improve absorption and transfer. The 3-D structure may include protrusions, recesses, raised areas, recessed areas, ripples, and channels. Holes 150 are typically arranged in a recessed area or valley between protrusions / ripples / channels. In other respects, holes 150 may be evenly or unevenly distributed, without regard to protrusions or valleys. In general, hydrophilic treatment agents are patterned to be arranged in valleys, and hydrophobic treatment agents are patterned to be arranged on protrusions or raised portions of a topographic surface.

[0056] Figure 2 An embodiment of a membrane described herein comprising pores is shown. Figure 2The membrane is shown in transition between the contracted state 200 and the expanded state 250. The membrane 205 includes one hole 210, but the membrane 205 may include multiple holes. As shown in the contracted state 200, the membrane 205 includes a star-shaped hole 210. It is expected that the membrane 205 and the hole 210 may have a variety of different shapes to provide a desired flow rate or flow pattern through the hole. For example, the hole can be circular, oval, rectangular, hexagonal, trapezoidal, T-shaped, L-shaped, hourglass-shaped, etc. In some embodiments, the membrane 205 may include a plurality of holes that form a pattern together. The pattern of the hole can provide a specific flow path for the fluid entering the absorbent article. For example, the pattern may include concentric circles in the liquid deposition area of ​​the absorbent article. In some embodiments, the hole accounts for at least 10% of the total surface area of ​​the membrane, such as at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50% or at least 55%. Liners including holes containing larger surfaces can provide faster fluid intake.

[0057] In the contracted state 200, the membrane 205 is dry and the pores 210 are open, providing openings for fluid intake. As described herein, the crystalline regions of the water-soluble polymer entangle with the aromatic thermoplastic polyurethane and pull the elastic aromatic thermoplastic polyurethane into the contracted state.

[0058] Figure 2 Also shown is a film 205 in a swollen state 250 after absorbing water. Under the swollen state 250, the expansion of the film 205 closes the hole 210, which prevents the fluid from flowing back. When the film 205 absorbs fluid (e.g., water), the water-soluble polymer begins to change from a crystalline state to an amorphous state. The morphological change of the water-soluble polymer from the contracted state 200 to the swollen state 250 effectively releases the elastic energy of the aromatic thermoplastic polyurethane, causing the film 205 to expand. In other words, due to the entanglement of the thermoplastic polyurethane chain with the hydrophilic water-soluble polymer chain, the film 205 expands as the water-soluble polymer expands. Therefore, the film 205 absorbs water from body fluids, and the morphological change of the water-soluble polymer is an amorphous state for film expansion.

[0059] Figure 3 Another embodiment of a membrane is shown including a bulls-eye pattern for fluid flow through the membrane. In this embodiment, the membrane 305 is cut or scored into a pattern including a bulls-eye shape including a plurality of holes 310 for fluid flow. Figure 3 The transition of the membrane 305 from an open valve position in a collapsed state 300 to a closed valve position in an expanded state 350 is shown.

[0060] When absorbing fluid (e.g., body fluid), the membrane 305 expands from the contracted state 300 to the expanded state 350. As the membrane 305 dries due to desorption of the fluid, the membrane 305 shrinks toward its original size in the contracted state 300. During the insult, the fluid will easily flow through the pores 310. As a portion of the membrane 305 absorbs the fluid, the membrane 305 begins to expand laterally along the edges of the pores 310 and begins to close these areas. When the insult is complete, the membrane 305 continues to grow until it closes the pores 310, as shown in FIG. Figure 3 300. The membrane 305 blocks the fluid from passing through the valve in the opposite direction by closing the hole 310. After a period of time, the membrane 305 dries out or releases the fluid, and the membrane shrinks to its original size in the collapsed state 300, opening the valve to cope with possible repeated insults of the fluid.

[0061] 4A to 4F Provided are multiple valve designs of films according to some embodiments of the present invention.In some embodiments, the film may include holes with various geometric shapes to control fluid flow rate, absorption and fluid reflux.The total open area of ​​the holes on the film can be adjusted according to the type of stain and the position of the stain to obtain enough fluid suction and valve closure.In some embodiments, the film can be cut, stamped or scored to form holes.For example, the film can be cut to include one or more slits.One or more slits can form a cross pattern.In some embodiments, the cross pattern of the slit forms a hole.Alternatively, the film can be manufactured to have one or more holes.In some embodiments, the film can be laser cut to provide a valve design in the film.Then, a part of the film can be bonded to a substrate to control the opening and closing of the valve.In some embodiments, the region adjacent to the valve design (for example, the region adjacent to one or more holes) is not bonded to the substrate to allow the film to expand.

[0062] Figure 4A A membrane including a plurality of holes is shown. In this embodiment, the membrane 400 includes a plurality of holes 405 spaced apart on the membrane 400. The holes 405 are substantially circular; however, the holes can have any suitable geometric shape (e.g., square, oval, polygonal, etc.). The holes 405 can be equally spaced apart on the membrane 400. The size of the holes 405 can be related to the flow rate of the fluid through the membrane. For example, Figure 4B Shown is a membrane 410 including a plurality of circular holes 415 having a larger cross-sectional area than holes 405 of membrane 400. Membrane 410 is expected to have a higher fluid flow rate than membrane 400.

[0063] Figure 4C and Figure 4DA membrane including a plurality of hexagonal holes is shown. The shapes of holes 425 and holes 435 of membrane 420 and membrane 430 are similar to the length and width of a conventional pad, respectively. The holes 425 of membrane 420 have the same elongated hexagonal shape as the holes 435 of membrane 430. Figure 4D Compared to the pores 435 of the membrane 430, Figure 4C The pores 425 of the membrane 420 have a smaller cross-sectional area. In this way, each of the membranes 420 and 430 can be customized for situations where lower and higher flow rates are desired. Figure 4E and Figure 4F A membrane comprising patterned holes is shown. Figure 4E The membrane 440 includes a bull's-eye shaped hole 445 . Figure 4E The membrane 450 includes a pattern comprising concentric circles 455 surrounding a central hole 460 .

[0064] Construction of absorbent articles

[0065] Figure 5 A cross-sectional view of a portion of an absorbent article according to some embodiments of the present invention is provided. The absorbent article 500 includes a laminate 505, an absorbent body 520, and a backing film 530. The laminate 505 includes a substrate 506 and a film 510. In some embodiments, the substrate 506 is nonwoven. The substrate 506 can be part of the top sheet or body side liner of the absorbent article 500. The film 510 includes a wearer-facing surface 512 and a clothing-facing surface 514. In some embodiments, the wearer-facing surface 512 of the film 510 is bonded to the substrate 506. In various embodiments, the laminate 505 of the absorbent article covers the absorbent body 520 and the backing film 530, and can isolate the wearer's skin from the liquid waste retained by the absorbent body 520. In some embodiments, a fluid transfer layer can be positioned between the laminate 505 and the absorbent body 520. In some embodiments, the laminate 505 can be bonded to an optional fluid transfer layer, the absorbent body 520, and / or the backing film 530. For example, the garment-facing surface 514 of the membrane 510 may be bonded to the fluid transfer layer by an adhesive and / or by point fusion bonding. The point fusion bonding may be selected from ultrasonic bonding, thermal bonding, pressure bonding, and combinations thereof.

[0066] The laminate 505 may include a plurality of holes 515. The holes 515 extend through the substrate 506 and the film 510 of the laminate 505. In this way, the laminate 505 can control the flow of fluid to the absorbent body 520. In some embodiments, the width of the hole 515 can gradually decrease from the substrate 506 through the film 510. In some embodiments, the hole 515 can have a uniform width throughout the laminate 505. A portion of the film 510 adjacent to the hole 515 may not be bonded to the substrate 506. For example, the area 516 adjacent to the hole at the interface of the substrate 506 and the film 510 is not bonded. This area 516 of the film 510 is not bonded to the substrate 506 to allow the film 510 to expand when in contact with body fluids. In some embodiments, the entire area 516 of the hole 515 adjacent to the film 510 is not bonded to the substrate 506. For example, in an embodiment where the hole is circular, the area of ​​the film around the periphery of the hole is not bonded to the substrate.

[0067] Figure 6 Another cross-sectional view of a portion of an absorbent article according to some embodiments of the present invention is provided. Figure 6 The film 610 of the laminate 605 is shown, which substantially encapsulates the absorbent body 620 between the backsheet 630 and the laminate 605. In some embodiments, the laminate 605 may extend beyond the absorbent body 620 and / or the fluid transfer layer (not shown) to cover a portion of the backsheet 630, and may be bonded thereto by any method deemed suitable, such as by an adhesive, to substantially encapsulate the absorbent body between the backsheet and the laminate. It is also envisioned that the laminate 605 may not extend beyond the absorbent body and / or may not be fixed to the backsheet. It is further envisioned that the film 610 may be composed of more than one material segment. The film 610 may have different shapes, including rectangular, hourglass, or any other shape. The laminate 605 may be appropriately conformable, soft and comfortable and non-irritating to the wearer's skin, and the film 610 may be the same or lower hydrophilicity as the absorbent body 620 to allow body exudates to easily penetrate into the absorbent body and provide a relatively dry surface for the wearer. The laminate 605 may include a plurality of holes 615. The apertures 615 extend through the substrate 606 and the film 610 of the laminate 605 to the absorbent body 620 .

[0068] membrane

[0069] Water-responsive film includes water-soluble polymer and aromatic thermoplastic polyurethane.When contacting with water in body fluid, the specific combination of polymer in water-responsive film, the form of polymer and the amount of polymer utilize the elastic energy expansion of polymer.For example, the polymer can produce the water-responsive film with enough crystallinity, so that the film can expand when contacting with fluid, and then can shrink to its original state when drying.In this respect, aromatic thermoplastic polyurethane is used as the elastic material of winding water-soluble polymer, to provide the expansion of film.Water-soluble polymer contributes to the crystallinity of film, so that when film is dry, water-soluble polymer recrystallizes and makes film shrink to its original size.Surprisingly and unexpectedly found that the combination of polymers described herein affects the ability and degree of water-responsive expansion and contraction.

[0070] In order to make the film have elastic properties for expansion and recovery, polymers are customized to provide a combination of elasticity and rigidity. For example, water-soluble polymers and aromatic thermoplastic polyurethanes are specially customized to produce a crystallinity of at least 25%, such as at least 30%, at least 35%, at least 40%, at least 45%, at least 50% or at least 55%. In some embodiments, the film can have a crystallinity of 25% to 60%, such as 30% to 60%, 30% to 55%, 35% to 55%, 35% to 50%, 40% to 60%, 45% to 60%, 40% to 50% or any value between these ranges. Water-soluble polymers mainly contribute to the crystalline properties of the film.

[0071] In some embodiments, the water-responsive film expands when it is kept in contact with the fluid until the growth of the final film reaches a maximum. Thereafter, continued contact with the fluid causes the film to begin to shrink. Without being bound by theory, it is believed that once a certain amount of water-soluble polymer dissolves, the chain entanglement is decoupled, and the expanded film shrinks due to dissolution. When the film is no longer in contact with the fluid, the remaining water-soluble polymer recrystallizes together with the thermoplastic polyurethane chains, and the film shrinks to its original size. The crystalline nature of the water-soluble polymer again utilizes the elastic energy of the elastomer, and if exposed to the fluid for the second time, the film can expand.

[0072] In some embodiments, the film can be monolayer or multilayer. The multilayer film can be prepared by coextrusion, extrusion coating or by any conventional layering process of the layer. In some embodiments, the multilayer film may include at least one substrate layer and at least one skin layer. In some embodiments, the multilayer film may include multiple layers. For example, the multilayer film may be formed by a substrate layer and one or more skin layers, wherein the substrate layer is formed by a blend of a water-soluble polymer and a thermoplastic polyurethane. In some embodiments, the skin layer is also formed by a polymer blend as described above. However, it should be understood that other polymers may also be used for the skin layer.

[0073] In some embodiments, film is bonded to at least one substrate to produce laminate.The film can be attached or bonded to at least one substrate.For example, the film can be bonded to at least one substrate.The film is bonded to at least one substrate (top and / or bottom) to control the lateral expansion and closure of the hole used as a valve.Laminate can include one or more holes so that the film can act as a valve due to its expansion and contraction characteristics.For example, a part of substrate can be bonded to film.This can be achieved by patterned (for example, cutting or punching) laminate, to leave a specific unbonded area adjacent to one or more holes of the film bonded to substrate.The lateral expansion of unbonded film allows the hole to close when contacting water.The amount of expansion (for example, lateral expansion) may be affected by the composition of the film, the ratio of water-soluble polymer to thermoplastic polyurethane and the amount of fluid that contacts thin.

[0074] For example, the films described herein can be bonded or attached to at least one substrate layer to regulate the amount of fluid flowing to the absorbent body. The film may include one or more holes to allow fluid to be sucked into the absorbent structure. The fluid contacting the film can reach the absorbent structure through the holes. A portion of the fluid can be absorbed by the film. The fluid absorbed by the film expands the film and closes the holes, thereby acting as a valve for the absorbent structure.

[0075] Thermoplastic polyurethane

[0076] The film may include one or more aromatic TPUs. The aromatic TPU is used as an elastic material to allow the film to expand. The combination of the aromatic TPU and the substantially crystalline water-soluble polymer in the film causes the film to expand after contact with body fluids, and then the film shrinks to its original size when drying or desorbing, which is a surprising and unexpected result. Compared with the membranes of the prior art, the ability of the membrane to expand and shrink to its original size when in contact with water enables the membrane to responsively close and open valves (e.g., holes), which only have the ability to shrink when in contact with water.

[0077] In some embodiments, aromatic TPU polymer is hydrophilic.TPU polymer can be based on the gross weight of film 10 wt % to 90 wt %, for example 15 wt % to 85 wt %, 20 wt % to 80 wt %, 25 wt % to 75 wt %, 30 wt % to 70 wt %, 30 wt % to 65 wt %, 30 wt % to 70 wt %, 35 wt % to 65 wt % or 40 wt % to 60 wt % amount is present in film.In some embodiments, film includes at least 10 wt % of TPU polymer, for example at least 15 wt %, at least 20 wt %, at least 25 wt %, at least 30 wt %, at least 35 wt %, at least 40 wt %, at least 45 wt %, at least 50 wt %, at least 55 wt %, at least 60 wt %, at least 65 wt % or at least 70 wt %.In some embodiments, film includes 40 wt % to 60 wt % of TPU.

[0078] The film includes the above amount of TPU to ensure that the elasticity of the film allows expansion. It was found that the chemical properties of the TPU contribute to the expansion characteristics of the film when in contact with water. Without being bound by theory, it is believed that when the TPU chains are entangled with a water-soluble polymer (e.g., polyethylene oxide), the hydrophilic aromatic TPU chains interact more extensively with the water-soluble polymer (through chain entanglement) than the hydrophobic aliphatic TPU chains. As a result, when in contact with water, the crystalline regions of the water-soluble polymer begin to transform into a more amorphous state, which causes the polymer to swell. The morphological changes of the water-soluble polymer during swelling effectively release the elastic energy of the aromatic TPU.

[0079] TPU is generally synthesized from polyols, organic diisocyanates, and optionally chain extenders. The synthesis of such melt-processable polyurethane elastomers can be carried out in steps (e.g., prepolymer dispensing process) or by reacting all components simultaneously in a single stage (e.g., single batch dispensing process), as known in the art and described in more detail in U.S. Pat. Nos. 3,963,656 to Meisert et al., 5,605,961 to Lee et al., 6,008,276 to Kalbe et al., 6,417,313 to Kirchmeyer et al., and 7,045,650 to Lawrey et al., and U.S. Patent Application Publication Nos. 2006 / 0135728 to Peerlings et al. and 2007 / 0049719 to Brauer et al., all of which are incorporated by reference in their entirety for all intents and purposes.

[0080] Polyols are generally any high molecular weight products with reactive active hydrogen components, and include materials with an average of about two or more hydroxyls per molecule. Long chain polyols can be used, including higher polymeric polyols, such as polyester polyols and polyether polyols, and other acceptable "polyol" reactants, which have active hydrogen components, such as polyester polyols, polyhydroxy polyester amides, hydroxyl-containing polycaprolactones, hydroxyl-containing acrylic copolymers, hydroxyl-containing epoxy resins, and hydrophobic polyalkylene ether polyols. Typically, polyols are substantially linear and have two to three hydroxyls, and the number average molecular weight is 450 to 10,000, for example 450 to about 6000 or 600 to 4500. Short chain glycols provide harder, more crystalline polymer segments, and long chain glycols provide softer, more amorphous polymer segments.

[0081] Suitable polyether diols can be prepared by, for example, reacting one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene residue with a starting molecule containing two or more active hydrogen atoms in a bonded form. Exemplary alkylene oxides include ethylene oxide, 1,2-propylene oxide, epichlorohydrin, and 1,2-butylene oxide and 2,3-butylene oxide. Exemplary starting molecules include water; amino alcohols such as N-alkyldiethanolamines (e.g., N-methyldiethanolamine); and diols such as ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, and 1,6-hexanediol. In some embodiments, suitable polyester diols include ethylene glycol polyadipate, 1,4-butylene glycol polyadipate, ethylene glycol / 1,4-butylene glycol polyadipate, 1,6-hexanediol / 1,4-butylene glycol polyadipate, and polylactone.

[0082] The organic diisocyanate may include aromatic diisocyanates such as 2,4-toluene diisocyanate or 2,6-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, naphthylene-1,5-diisocyanate, xylene diisocyanate, methylene diphenyl isocyanate (“MDI”), hexamethylene diisocyanate (“HMDI”), mixtures thereof, and the like.

[0083] Chain extenders typically have a number average molecular weight of about 60 to 400 and include amino, thiol, carboxyl and / or hydroxyl functional groups. In some embodiments, the chain extender includes two to three hydroxyl groups. As described above, one or more compounds selected from aliphatic diols containing 2 to 14 carbon atoms can be used as chain extenders. Such compounds include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane and neopentyl glycol. Diesters of terephthalic acid and diols with 2 to 4 carbon atoms can also be used. Some examples of such compounds include diethylene glycol terephthalate and dibutylene glycol terephthalate, hydroxyalkylene ethers of hydroquinone (e.g., 1-4-bis(β-hydroxyethyl)hydroquinone), ethoxylated bisphenols (e.g., 1,4-bis(β-hydroxyethyl)bisphenol A), (cyclo)aliphatic diamines (e.g., isophoronediamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, N-methyl-1,3-propylenediamine, and N,N′-dimethylethylenediamine), and aromatic diamines (e.g., 2,4-toluenediamine, 2,6-toluenediamine, 3,5-diethyl-2,4-toluenediamine, and 3,5-diethyl-2,6-toluenediamine, as well as primary mono-, di-, tri-, or tetra-alkyl-substituted 4,4′-diaminodiphenylmethane).

[0084] In addition to those mentioned above, other components can also be used to form TPU. For example, a catalyst can be used to promote the formation of polyurethane. Suitable catalysts include, for example, tertiary amines, such as triethylamine, dimethylcyclohexyl-amine, N-methylmorpholine, N, N'-dimethylpiperazine, 2-(dimethylaminoethoxy)-ethanol, diazabicyclo [2.2.2] octane, and metal compounds, such as titanates, tin diacetate, tin dioctoate, tin dilaurate or dialkyltin salts of aliphatic carboxylic acids, such as dibutyltin diacetate or dibutyltin dilaurate or other similar compounds. Other suitable additives that can be used include light stabilizers (for example, hindered amines), chain terminators, slip agents and release agents (for example, fatty acid esters, their metal soaps, fatty acid amides, fatty acid ester amides and silicone compounds), plasticizers, anti-blocking agents, inhibitors, stabilizers that resist hydrolysis, heat and discoloration, dyes, pigments, inorganic and / or organic fillers, antibacterial and antibacterial active substances, fillers, etc.

[0085] In some embodiments, the melting point of the TPU is from 75°C to 250°C, such as from 100°C to 240°C or from 120°C to 220°C. The glass transition temperature (“T g ”) may be relatively low, such as -150°C to 0°C, such as -100°C to 10°C and -85°C to 20°C. The melting temperature and glass transition temperature can be determined using differential scanning calorimetry (“DSC”) in accordance with ASTM D-3417.

[0086] Examples of aromatic TPUs used in the films described herein include those available from Lubrizol Co. under the name ESTANE TM 、PEARLSTICK TM AND PEARLBOND TM TPU of , and TPU available from Wanhua Chemical Group Co., Ltd. under the name For example, ESTANE TM 58238、ESTANE TM EZ-44-61EXP and WHT-F170 is an aromatic polyester-based polyurethane that can be used in the films described herein. TM MVT 75AT3 is an aromatic polyether-based polyurethane useful in the films described herein.

[0087] Other physical properties of TPU may affect the ability and degree of water-responsive expansion of the membrane described herein. Table 1 provides several grades of TPU and their chemical and physical properties. The tensile strength and tensile modulus of TPU are important parameters for supporting robust expansion of the membrane. For example, an aromatic TPU with poor tensile strength and low molecular weight may not be able to support strong expansion of the membrane. On the other hand, if the tensile modulus is too high, the aromatic TPU may be too hard to expand, and the TPU may not have enough elasticity to expand the membrane.

[0088] In some embodiments, the tensile modulus of the TPU can range from 0.5 MPa to 8 MPa, such as 0.75 MPa to 7 MPa, 0.9 MPa to 6 MPa, 1 MPa to 5.5 MPa, 1 MPa to 5 MPa, 1.5 MPa to 4.5 MPa, or 2 MPa to 4 MPa, at 100% elongation as measured according to ASTM D-412 (2022). In some embodiments, the tensile modulus of the TPU can range from 1 MPa to 5 MPa at 100% elongation as measured according to ASTM D-412 (2022).

[0089] In some embodiments, the tensile strength of the TPU may range from 5 MPa to 100 MPa, such as 10 MPa to 80 MPa, 15 MPa to 60 MPa, 20 MPa to 50 MPa, 25 MPa to 50 MPa, 30 MPa to 60 MPa, or 30 MPa to 50 MPa. In some embodiments, the tensile strength of the TPU may range from 20 MPa to 50 MPa.

[0090] In some embodiments, the Shore hardness value of the TPU can range from 50 to 90, 55 MPa to 85 MPa, 60 MPa to 80 MPa, 60 MPa to 75 MPa, 65 MPa to 80 MPa, or 70 MPa to 80 MPa as measured by ASTM D-2240 (2022). In some embodiments, the Shore hardness value of the TPU can range from 60 to 80.

[0091] TPU-1 means aromatic polyether-based thermoplastic polymer. The product can be called ESTANE TM MVT 75AT3 (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0092] TPU-2 stands for aromatic polyester-based thermoplastic polymer. WHT-F170 (Wanhua) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0093] TPU-3 means aromatic polyester based thermoplastic polymer. The product can be called ESTANE TM The properties of the thermoplastic can be found in Table 1 below.

[0094] TPU-4 means aromatic polyester based thermoplastic polymer. The product can be called ESTANE TM EZ-44-61EXP (Pearlbond 405EXP) (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0095] TPU-5 stands for aromatic polyester-based thermoplastic polymer. 5702F3 (Lubrizol). The properties of the thermoplastic can be found in Table 1 below.

[0096] TPU-6 stands for aromatic polyester-based thermoplastic polymer. 302EXP (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0097] TPU-7 stands for aromatic polyester-based thermoplastic polymer. 305EXP (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0098] TPU-8 represents an aliphatic polyether-based thermoplastic polymer. As used herein, the product can be used as a comparative example to compare aromatic-based thermoplastic polymers with aliphatic thermoplastic polymers. The product can be referred to as ESTANE TM AG 8451 (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0099] TPU-9 means an aliphatic polyether-based thermoplastic polymer. As used herein, the product can be used as a comparative example for comparing aromatic-based thermoplastic polymers to aliphatic thermoplastic polymers. The product can be named LL1275A10 (BASF) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0100] TPU-10 represents an aliphatic polyester-based thermoplastic polymer. As used herein, the product can be used as a comparative example to compare aromatic-based thermoplastic polymers with aliphatic thermoplastic polymers. The product may be referred to as ESTANE TM CLC93A-V (Lubrizol) was obtained. The properties of the thermoplastic can be found in Table 1 below.

[0101]

[0102]

[0103] Table 1 highlights the importance of the chemical nature of the TPU, which is evident by comparing the aliphatic and aromatic characteristics of the TPU in the third column. Each TPU in Table 1 was blended with a water-soluble polymer and extruded into films to study the effect of the TPU on the properties of the films. Each film produced from the aromatic TPU swells when in contact with water, while films produced from aliphatic TPUs (polyether-based and polyester-based) shrink when in contact with water. TPU-9 is an aliphatic polyether-based TPU with physical properties similar to TPU-1 (aromatic polyether-based TPU) and TPU-2 (aromatic polyester-based TPU). However, the films containing the aliphatic polyether TPU-9 shrunk, while the films containing the aromatic polyether TPU-1 and aromatic polyester TPU-2 both swelled.

[0104] TPU-8 is an aliphatic polyether-based TPU with physical properties similar to TPU-3 (aromatic polyester-based TPU). The film produced from the aromatic polyether-based TPU expands again, while the film containing the aliphatic polyether-based TPU shrinks. All aromatic TPUs are examples of elastomers that can be used for the water-responsive swellable membranes described herein. Other aromatic TPUs that are expected to have physical properties similar to those in Table 1 represent other exemplary elastomeric components that can be used for the membranes described herein.

[0105] Water soluble polymer

[0106] Film also includes one or more water-soluble polymers.Water-soluble polymer can be based on the gross weight 10 % by weight to 90 % by weight of film, for example 15 % by weight to 85 % by weight, 20 % by weight to 80 % by weight, 25 % by weight to 75 % by weight, 30 % by weight to 70 % by weight, 30 % by weight to 65 % by weight, 30 % by weight to 70 % by weight, 35 % by weight to 65 % by weight or 40 % by weight to 60 % by weight amount is present in film.In some embodiments, film includes at least 10 % by weight of water-soluble polymer, for example at least 15 % by weight, at least 20 % by weight, at least 25 % by weight, at least 30 % by weight, at least 35 % by weight, at least 40 % by weight, at least 45 % by weight, at least 50 % by weight, at least 55 % by weight, at least 60 % by weight, at least 65 % by weight or at least 70 % by weight.In some embodiments, film includes the water-soluble polymer of 40 % by weight to 60 % by weight based on the gross weight of film.

[0107] In some embodiments, the water-soluble polymer has a substantially crystalline (e.g., at least 50% crystallinity) morphology. The expansion and contraction properties of the film depend in part on the morphology and molecular weight of the water-soluble polymer. For example, the crystalline morphology of the water-soluble polymer enables the water-soluble polymer to transition from a crystalline state to an amorphous state when in contact with water. When the film is no longer in contact with the fluid, the remaining water-soluble polymer recrystallizes with the TPU chains, and after desorption or drying, the film shrinks to its original size. The crystalline nature of the water-soluble polymer "locks" the elastic energy of the elastomer (e.g., TPU).

[0108] The water-soluble polymer contributes to the crystallinity of the film. In some embodiments, the water-soluble polymer comprises a crystallinity greater than 50%. For example, the water-soluble polymer comprises a crystallinity greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, or greater than 90%. In some embodiments, the water-soluble polymer comprises a crystallinity of 50% to 95%, for example, 55% to 95%, 60% to 95%, 65% to 90%, 70% to 90%, 75% to 90%, or 80% to 95%.

[0109] In some embodiments, the water-soluble polymers used in the films described herein generally have a high molecular weight. For example, the water-soluble polymers may have a weight average molecular weight (MW) greater than 25,000, greater than 50,000, greater than 75,000, greater than 100,000, greater than 125,000, greater than 150,000, greater than 175,000, greater than 200,000, greater than 225000, or greater than 250,000. w In some embodiments, the water-soluble polymer has a weight average molecular weight (MW) of 25,000 g / mol to 500,000 g / mol, e.g., 50,000 g / mol to 475,000 g / mol, 75,000 g / mol to 450,000 g / mol, 80,000 g / mol to 400,000 g / mol, 90,000 g / mol to 350,000 g / mol, 100,000 g / mol to 300,000 g / mol, 100,000 g / mol to 250,000 g / mol, 100,000 g / mol to 200,000 g / mol, or 150,000 g / mol to 250,000 g / mol. w In some embodiments, the water-soluble polymer is polyethylene oxide. In some embodiments, the polyethylene oxide has a weight average molecular weight (M) greater than 25,000, greater than 50,000, greater than 75,000, greater than 100,000, greater than 125,000, greater than 150,000, greater than 175,000, greater than 200,000, greater than 225000, or greater than 250,000. w).

[0110] As described herein, the water-soluble polymer and aromatic TPU are specifically tailored to produce films having a crystallinity of 25% to 60%. The water-soluble polymer primarily contributes to the crystalline nature of the film. In some embodiments, the water-soluble polymer may include polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelatinized starch, nylon copolymers, polyacrylic acid, and mixtures thereof.

[0111] PEO-1 means water dispersible polyethylene oxide polymer. The product can be called POLYOX TM WSR N-80 was obtained and obtained from DuPont, Inc.

[0112] PEO-2 stands for water dispersible polyethylene oxide polymer. The product can be called POLYOX TM WSR N-10 was obtained and obtained from DuPont, Inc.

[0113] PVOH-1 means water dispersible polyvinyl alcohol polymer. The product name can be NICHIGO G-POLYMER TM OKS-8035 was obtained and obtained from Soarus, Inc.

[0114] In some embodiments, the water-soluble polymer can be polyethylene oxide (PEO). For example, a commercially available polyethylene oxide with high crystallinity is PEO-1. Table 2 provides a thermal analysis of a film including PEO-1 and TPU-2 (which is an aromatic TPU). The film including 100% by weight polyethylene oxide exhibits 77% crystallinity, as measured by differential scanning calorimetry (DSC) thermal analysis. Each composition including a blend of PEO-1 and TPU-2 exhibits sufficient crystallinity to swell when in contact with water. Based on DSC analysis, the film including 100% by weight TPU does not exhibit any crystallinity due to their amorphous morphology.

[0115]

[0116] In some embodiments, the water-soluble polymer can be formed from monomers such as vinyl pyrrolidone, hydroxyethyl acrylate or hydroxyethyl methacrylate (e.g., 2-hydroxyethyl methacrylate), hydroxypropyl acrylate or hydroxypropyl methacrylate, acrylic acid or methacrylic acid, acrylic acid or methacrylate or vinyl pyridine, acrylamide, vinyl acetate, vinyl alcohol (hydrolyzed from vinyl acetate), ethylene oxide, derivatives thereof, etc. Other examples of suitable monomers are described in U.S. Pat. No. 4,499,154 to James et al., which is incorporated by reference as a whole for all intents and purposes. The resulting polymer can be a homopolymer or copolymer (e.g., copolymer, terpolymer, etc.), and can be nonionic, anionic, cationic or amphoteric. In addition, the polymer can be of one type (i.e., homogeneous), or a mixture of different polymers can be used (i.e., heterogeneous). In a specific embodiment, the water-soluble polymer comprises repeating units having functional hydroxyl groups, such as polyvinyl alcohol ("PVOH"), copolymers of polyvinyl alcohol (e.g., ethylene vinyl alcohol copolymer, methyl methacrylate vinyl alcohol copolymer, etc.). The vinyl alcohol polymer has, for example, at least two or more vinyl alcohol units in a molecule, and may be a homopolymer of vinyl alcohol or a copolymer including other monomer units.

[0117] The degree of hydrolysis can be selected to optimize the solubility of the water-soluble polymer, etc. For example, the degree of hydrolysis can be from 60 mol% to 95 mol%, such as from 80 mol% to 90 mol% or from 85 mol% to 89 mol%. An example of a suitable partially hydrolyzed polyvinyl alcohol polymer may be named CELVOL TM 203, 205, 502, 504, 508, 513, 518, 523, 530 or 540 are available from Celanese Corp. Other suitable partially hydrolyzed polyvinyl alcohol polymers are available under the name ELVANOL TM 50-14, 50-26, 50-42, 51-03, 51-04, 51-05, 51-08 and 52-22 were obtained from DuPont.

[0118] The relative amounts of water-soluble polymer and TPU used in the film can also be selected to help further optimize the expansion and contraction characteristics of the film. In some embodiments, the weight ratio of water-soluble polymer to TPU is 0.5:1 to 8:1, such as 1:1 to 7:1, 1.25:1 to 6:1, 1.5:1 to 5:1, 1.5:1 to 4:1, 1.5:1 to 3:1, 1.5:1 to 2.5:1, 1:1 to 3:1, or 1.25:1 to 2:1. Based on the total weight of the film, TPU can account for 10 wt% to 90 wt%, such as 15 wt% to 60 wt% or about 20 wt% to about 50 wt%. Based on the total weight of the film, the water-soluble polymer can account for 10 wt% to 90 wt%, such as 20 wt% to 80 wt% or 40 wt% to 70 wt%.

[0119] additive

[0120] In some embodiments, the film may optionally include one or more additives. In some embodiments, the additive may include a surfactant, an absorbent, a plasticizer, a mineral, an antibiotic or a skin benefit agent. For example, the film may include a superabsorbent polymer. Superabsorbent polymers are generally used to increase the absorptive capacity and expansion of the film. In some embodiments, superabsorbent polymers are present in the film in the form of small particles. The superabsorbent polymer powders suitable for film include but are not limited to various anionic, cationic and nonionic materials. Suitable polymers include polyacrylamide, polyvinyl alcohol, ethylene maleic anhydride copolymer, polyvinyl ether, polyacrylic acid, polyvinyl pyrrolidone, polyethylene morpholine, polyamine, polyethyleneimine, polyquaternary ammonium, natural polysaccharide polymers (such as carboxymethyl cellulose), carboxymethyl starch, hydroxypropyl cellulose, alginate, alginate, carrageenan, acrylic acid grafted starch, acrylic acid grafted cellulose, chitin, chitosan and synthetic polypeptides (such as polyaspartic acid, polyglutamic acid, polyglutamic acid, polylysine and polyarginine), and salts, copolymers and mixtures of any one of the aforementioned polymers.

[0121] In addition to the components mentioned above, other additives may also be added to the lining, such as slip additives (e.g., fatty acid salts, fatty acid amides, etc.), compatibilizers (e.g., functionalized polyolefins), dispersing aids, melt stabilizers, processing stabilizers, heat stabilizers, light stabilizers, antioxidants, heat aging stabilizers, brighteners, anti-blocking agents, adhesives, lubricants, fillers, etc.

[0122] In some embodiments, the film may include a filler. Fillers are microparticles or other forms of materials that can be added to the film polymer extrusion blend and do not chemically interfere with the film, but can be evenly dispersed throughout the film. Fillers can serve multiple purposes, including enhancing the opacity and / or breathability of the film (i.e., vapor permeable and substantially liquid impermeable). For example, the filled film can be made breathable by stretching, which causes the polymer to separate from the filler and form microporous channels. Breathable microporous elastic films are described, for example, in U.S. Patents Nos. 5,997,981, 6,015,764, and 6,111,163 to McCormack et al.; U.S. Patent No. 5,932,497 to Morman et al.; and U.S. Patent No. 6,461,457 to Taylor et al., which are incorporated by reference in their entirety for all intents and purposes. In addition, hindered phenols are commonly used as antioxidants in film manufacturing. Some suitable hindered phenols include those available under the trade name (such as The present invention also can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention. The present invention can be used to prepare the film of the present invention.

[0123] Negatives

[0124] In some embodiments, absorbent article comprises backsheet.Backsheet and / or its part can be liquid impermeable and optionally breathable.Backsheet and / or its part can be elastic, stretchable or non-stretchable.Backsheet can be constructed of single layer, multilayer, laminate, spunbond fabric, film, liner, meltblown fabric, elastic netting, microporous web, bonded carded web or foam provided by elastomeric material or polymer material.In some embodiments, backsheet can be constructed of microporous polymer film (such as polyethylene or polypropylene).In some embodiments, backsheet can be single layer liquid impermeable material.In some embodiments, backsheet can be suitably stretchable in at least lateral or circumferential direction of absorbent article, and more suitably elastic.

[0125] In some embodiments, the backsheet can be a multilayer laminate, wherein at least one layer is liquid impermeable. In some embodiments, the backsheet can be a two-layer structure, which includes an outer layer material and an inner layer material that can be bonded together, such as by a laminate adhesive. Suitable laminate adhesives can be applied in a continuous or intermittent manner as beads, sprays, parallel swirls, etc. Suitable adhesives can be purchased from Bostik Findlay Adhesives, Inc. in Wauwatosa, Wisconsin, USA. It should be understood that the inner layer can be bonded to the outer layer by other bonding methods, including but not limited to ultrasonic bonding, thermal bonding, pressure bonding, etc.

[0126] The outer layer of the backsheet may be any suitable material and may be a material that provides a generally cotton-like texture or appearance to the wearer. An example of such a material may be a 100% polypropylene bonded carded web with a diamond bond pattern, such as 30 gsm Sawabond®, available from Sandler AG of Germany. Or equivalent. Another example of a material suitable for use as the outer layer of the backsheet can be a 20 gsm spunbonded polypropylene nonwoven web. The liquid-impermeable inner layer of the backsheet (or a liquid-impermeable backsheet, wherein the backsheet has a single-layer construction) can be vapor-permeable (i.e., "breathable") or vapor-impermeable. The liquid-impermeable inner layer (or a liquid-impermeable backsheet, wherein the backsheet has a single-layer construction) can be made of a plastic liner, but other liquid-impermeable materials can also be used. The liquid-impermeable inner layer (or a liquid-impermeable backsheet, wherein the backsheet has a single-layer construction) can inhibit liquid body exudates from seeping out of the absorbent article and wetting articles such as bed sheets and clothing, as well as the wearer and caregiver. An example of a material for a liquid-impermeable inner layer (or a liquid-impermeable backsheet where the backsheet has a single-layer construction) can be a printed 19 gsm Berry Plastics XP-8695H liner or equivalent commercially available from Berry Plastics Corporation of Evansville, IN, USA. Where the backsheet is a single-layer structure, it can be embossed and / or matte treated to provide a more cloth-like texture or appearance. The backsheet can allow vapor to escape from the absorbent article while preventing liquid from passing through. Suitable liquid-impermeable, vapor-permeable materials can be composed of a microporous polymer liner or a nonwoven material that has been coated or otherwise treated to impart a desired level of liquid impermeability.

[0127] Absorption body

[0128] The absorbent body can be appropriately constructed to be substantially compressible, conformable, flexible, non-irritating to the wearer's skin, and capable of absorbing and retaining fluids. The absorbent body can be made into a variety of sizes and shapes (e.g., rectangular, trapezoidal, T-shaped, I-shaped, hourglass-shaped, etc.), and made of a variety of materials. The size and absorption capacity of the absorbent body should be compatible with the body shape of the intended wearer and the liquid load applied by the intended use of the absorbent article. In addition, the size and absorption capacity of the absorbent body can be varied to accommodate wearers ranging from infants to adults.

[0129] The absorbent body may have a surface facing the garment and a surface facing the wearer. In some embodiments, the surface facing the wearer may be adjacent to the film, and the surface facing the garment may be adjacent to the backsheet. In some embodiments, the absorbent body may be composed of a web material, woven or nonwoven sheet, scrim netting or other stable structure of hydrophilic fibers, cellulose fibers (e.g., wood pulp fibers), natural fibers, synthetic fibers, superabsorbent materials, binder materials, surfactants, selected hydrophobic and hydrophilic materials, pigments, lotions, odor control agents, etc., and combinations thereof. In some embodiments, the absorbent body may be a matrix of cellulose fluff and superabsorbent material.

[0130] In some embodiments, the absorbent body can be constructed of a single layer of material, or in an alternative, can be constructed of two or more layers of material. In some embodiments, wherein the absorbent body has two layers. The absorbent body may have a layer facing the wearer and / or a layer facing clothes containing superabsorbent material. In some embodiments, the absorbent body may have a layer facing the wearer that is suitably composed of hydrophilic fibers and a layer facing clothes that is suitably at least partially composed of a high-absorbency material commonly referred to as a superabsorbent material. In this embodiment, the layer facing the wearer of the absorbent body can be suitably composed of cellulose fluff (such as wood pulp fluff), and the layer facing clothes of the absorbent body can be suitably composed of a superabsorbent material or a mixture of cellulose fluff and superabsorbent material. Therefore, the layer facing the wearer can have a lower absorption capacity per unit weight than the layer facing clothes. The layer facing the wearer can also be composed of a mixture of hydrophilic fibers and superabsorbent materials. It can also be conceived that in some embodiments, without departing from the scope of the present disclosure, the layer facing clothes can be composed only of superabsorbent materials.

[0131] Various types of wettable, hydrophilic fibers can be used in the absorbent body. Examples of suitable fibers include: natural fibers; cellulosic fibers; synthetic fibers composed of cellulose or cellulose derivatives, such as rayon; inorganic fibers composed of essentially wettable materials, such as glass fibers; synthetic fibers made of essentially wettable thermoplastic polymers, such as certain polyester or polyamide fibers, or synthetic fibers composed of non-wettable thermoplastic polymers, such as polyolefin fibers that have been hydrophilized by suitable means. For example, the fibers can be hydrophilized by treatment with a surfactant, treatment with silica, treatment with a material having a suitable hydrophilic portion that is not easily removed from the fibers, or by coating non-wettable hydrophobic fibers with a hydrophilic polymer during or after fiber formation. For example, one suitable type of fiber is wood pulp, which is a bleached, highly absorbent sulfate wood pulp containing primarily softwood fibers. However, wood pulp can be exchanged with other fiber materials, such as synthetic, polymeric or meltblown fibers, or a combination of meltblown and natural fibers. In some embodiments, the cellulose fluff can include a blend of wood pulp fluff. The absorbent body can be formed by dry forming technology, air forming technology, wet forming technology, foam forming technology, etc. and their combination. Co-forming nonwoven materials can also be used. Methods and equipment for performing such technologies are well known in the art. Suitable superabsorbent materials can be selected from natural, synthetic and modified natural polymers and materials. Superabsorbent materials can be inorganic materials such as silica gel or organic compounds such as cross-linked polymers. Crosslinking can be covalent, ionic, van der Waals or hydrogen bonding. Typically, superabsorbent materials can be able to absorb at least about ten times its weight of liquid. In some embodiments, superabsorbent materials can absorb up to forty times its weight of liquid. Examples of superabsorbent materials include polyacrylamide; polyvinyl alcohol; ethylene maleic anhydride copolymer; polyvinyl ether; hydroxypropyl cellulose; carboxymethyl cellulose; polyvinyl morpholinone; polymers and copolymers of vinyl sulfonic acid, polyacrylate, polyacrylamide, polyvinyl pyrrolidone, etc. Other polymers suitable for superabsorbent materials include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, polyacrylate and isobutylene maleic anhydride copolymer, and mixtures thereof. The superabsorbent material can be in the form of discrete particles. The discrete particles can be any desired shape, such as a spiral or semi-spiral, a cube, a rod, a polyhedron, etc. Shapes with a maximum size / minimum size ratio (such as needles, flakes, and fibers) are also contemplated for use herein. Agglomerates of particles of superabsorbent material can also be used in the absorbent body.

[0132] In some embodiments, the absorbent body can have at least about 15% by weight of superabsorbent material based on the gross weight of the absorbent body. In some embodiments, the absorbent body can have at least about 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% by weight of superabsorbent material. In some embodiments, the absorbent body can be free of superabsorbent material.

[0133] Fluid transfer layer

[0134] In some embodiments, the absorbent article may include a fluid transfer layer. In some embodiments, the fluid transfer layer may be in contact with the absorbent body. In some embodiments, the fluid transfer layer may be bonded to the absorbent body. The bonding of the fluid transfer layer to the absorbent body may be performed by any means known to ordinary technicians, such as but not limited to adhesives. In some embodiments, the fluid transfer layer may be positioned between the film and the absorbent body. In some embodiments, the fluid transfer layer may completely cover the absorbent body and may be sealed to itself. In such embodiments, the fluid transfer layer may be folded over itself and then sealed using, for example, heat and / or pressure. In some embodiments, the fluid transfer layer may be composed of separate sheets of material that can be used to partially or completely cover the absorbent body and can be sealed together using sealing means, such as but not limited to ultrasonic bonding or other thermochemical bonding means or using adhesives.

[0135] In some embodiments, the fluid transfer layer may be in contact with and / or bonded to the wearer-facing surface of the absorbent body. In some embodiments, the fluid transfer layer may be in contact with and / or bonded to the wearer-facing surface and at least one edge of the absorbent body. In some embodiments, the fluid transfer layer 72 may be in contact with and / or bonded to the wearer-facing surface, at least one edge of the absorbent body, and the garment-facing surface of the absorbent body. In some embodiments, the absorbent body may be partially or completely surrounded by the fluid transfer layer.

[0136] The fluid transfer layer can be flexible, less hydrophilic than the absorbent body, and sufficiently porous to allow liquid body exudates to penetrate the fluid transfer layer to reach the absorbent body. In some embodiments, the fluid transfer layer can have sufficient structural integrity to withstand wetting by it and the absorbent body. In some embodiments, the fluid transfer layer can be constructed from a single layer of material, or it can be a laminate constructed from two or more layers of material.

[0137] In some embodiments, the fluid transfer layer may include, but is not limited to, natural and synthetic fibers such as, but not limited to, polyester, polypropylene, acetate, nylon, polymeric materials, cellulosic materials (such as wood pulp, cotton, rayon, viscose, such as available from Lenzing Company, Austria), or mixtures of these or other cellulosic fibers), and combinations thereof. Natural fibers may include, but are not limited to, wool, cotton, flax, hemp, and wood pulp. Wood pulp may include, but is not limited to, standard softwood fluff grades, which are bleached, highly absorbent sulfate pulps containing primarily southern softwood fibers. In some embodiments, the fluid transfer may include an air-bonded carded web comprised of synthetic fibers. For example, the synthetic fibers may include monocomponent polyolefin fibers or polyester fibers. In some embodiments, the fluid transfer may also include bicomponent fibers comprising polyolefins and / or polyesters.

[0138] In various embodiments, the fluid transfer layer may include a cellulosic material. In various embodiments, the fluid transfer layer may be a crepe filler or a high-strength tissue. In various embodiments, the fluid transfer layer may include a polymeric material. In some embodiments, the fluid transfer layer may include a spunbond material. In some embodiments, the fluid transfer layer may include a meltblown material. In some embodiments, the fluid transfer layer may be a laminate of a meltblown nonwoven material with fine fibers, which is laminated to at least one spunbond nonwoven material layer with coarse fibers. In such embodiments, the fluid transfer layer may be a spunbond-meltblown ("SM") material. In some embodiments, the fluid transfer layer may be a spunbond-meltblown-spunbond ("SMS") material. A non-limiting example of such a fluid transfer layer may be a 10gsm SMS material.

[0139] In some embodiments, the fluid transfer layer can be composed of at least one material that has been hydraulically entangled in a nonwoven substrate. In some embodiments, the fluid transfer layer can be composed of at least two materials that have been hydraulically entangled in a nonwoven substrate. In some embodiments, the fluid transfer layer can have at least three materials that have been hydraulically entangled in a nonwoven substrate. The non-limiting example of the fluid transfer layer can be a 33gsm hydraulically entangled substrate. In this example, the fluid transfer layer can be a 33gsm hydraulically entangled substrate composed of a 12gsm spunbond material, a 10gsm wood pulp material having a length of about 0.6cm to about 5.5cm, and a 11gsm polyester staple fiber material. In order to manufacture the fluid transfer layer just described, the 12gsm spunbond material can provide a base layer, and the 10gsm wood pulp material and the 11gsm polyester staple fiber material can be uniformly mixed together and deposited on the spunbond material, and then hydraulically entangled with the spunbond material.

[0140] In some embodiments, a wet strength agent may be included in the fluid transfer layer. A non-limiting example of a wet strength agent may be Kymene 6500 (557LK) or its equivalent available from Ashland Inc. of Ashland, KY, USA. In some embodiments, a surfactant may be included in the fluid transfer layer. In some embodiments, the fluid transfer layer may be hydrophilic. In some embodiments, the fluid transfer layer may be hydrophobic and may be treated in any manner known in the art to become hydrophilic.

[0141] In some embodiments, the fluid transfer layer may be in contact with and / or bonded to an absorbent body that is at least partially made of particulate material, such as superabsorbent material. In some embodiments in which the fluid transfer layer at least partially or completely surrounds the absorbent body, the fluid transfer layer should not be stretched or stretched unduly, as this may cause the particulate material to escape from the absorbent body. In some embodiments, the fluid transfer layer may have respective extension values ​​of 30% or less and 40% or less, respectively, in the cross direction and at peak load in the machine in the dry state.

[0142] Method of producing lining

[0143] Any known technology can be used to form film as described herein, including blow molding, casting, flat die extrusion, etc. In some embodiments, film can be formed by a blow molding process, wherein gas (e.g., air) is used to expand the bubbles of the extruded polymer blend through an annular die. The bubbles then collapse and are collected in the form of a flat film. The process for producing blown film is described in, for example, U.S. Patent No. 3,354,506 to Raley, U.S. Patent No. 3,650,649 to Schippers, and U.S. Patent No. 3,801,429 to Schrenk et al., and U.S. Patent Application Publication No. 2005 / 0245162 to McCormack et al. and U.S. Patent Application Publication No. 2003 / 0068951 to Boggs et al., all of which are incorporated by reference as a whole for all intents and purposes. In another embodiment, film is formed using a casting technique.

[0144] In some embodiments, the film can be formed by blending the components together using any of a variety of known techniques. In one embodiment, for example, the components can be provided individually or in combination. For example, the components can first be dry-mixed together to form a substantially uniform mixture, and they can likewise be supplied simultaneously or successively to a melt processing device (e.g., an extruder) that uniformly blends the materials.

[0145] In some embodiments, the method for producing film can include batch and / or continuous melt processing technology.For example, mixer / kneader, Banbury mixer, Faro continuous mixer, single screw extruder, twin screw extruder, rolling mill etc. can be utilized to blend and melt process these materials.The example of suitable melt processing device can include co-rotating twin screw extruder (for example, the USALAB twin screw extruder that can be obtained from Thermo Electron Corporation of Stone, England or the extruder that can be obtained from Werner-Pfreiderer of Ramsey, New Jersey (Ramsey, NJ)).Such extruder can include feed port and vent and provide high intensity distributed and dispersed mixing.For example, component can be fed to the same or different feed port of twin screw extruder and melt blended to form substantially uniform molten mixture.If desired, other additives can also be injected into polymer melt and / or be fed to extruder respectively at different positions along the length of extruder.

[0146] In some embodiments, the film can be produced in a melt blending device. For example, the water-soluble polymer and the TPU can be melt blended and extruded in an extruder. The water-soluble polymer and the TPU can be supplied to the extruder separately, where they are uniformly blended. In some embodiments, a single screw extruder or a twin screw extruder (e.g., a co-rotating twin screw extruder) can be used to produce the film. Commercially available single screw extruders suitable for producing films include, for example, HAAKE from Thermo Fisher Scientific of Waltham, MA. TM Rheomex OS single screw extruder. Commercially available twin screw extruders include, for example, the ZSK-30 extruder available from Werner & Pfleiderer Corporation of Ramsey, NJ, or the Thermo Prism Extruder available from Thermo Electron Corp. of Stone, England. TM USALAB 16 extruder. In some embodiments, melt blending can be carried out at a temperature of 50°C to 300°C, such as 75°C to 250°C, 100°C to 225°C, 120°C to 215°C, or 120°C to 200°C. In some embodiments, the screw speed of the extruder can be up to 200RPM. The polymer melt from the extruder can be processed in a film die to produce a film. In some embodiments, the film can be collected on one or more cooling rollers.

[0147] In some embodiments, film can be produced by two-step process, including compounding and extruding film. In this embodiment, water-soluble polymer and TPU can be compounded into pellets, and the pellets can be extruded to produce film. For example, water-soluble polymer and TPU can be melt blended to form uniform polymer blends by twin screw extruder at extrusion temperature. The molten polymer blend can then be extruded through a filament die to produce a sheet. After this, the extruded material can be cooled and cut into pellet form. In some embodiments, the extruded material can be air cooled using a fan on a conveyor, and then cut into pellets using a pelletizing system. The compounded pellets can be melted in another twin screw extruder at extrusion temperature and extruded onto a chill roll through a film die.

[0148] Fig. 7A A flow chart of a method for producing a laminate including a water-responsive film that can be used for absorbent articles is provided according to some embodiments. In some embodiments, a method 700 for producing a laminate is provided. Method 700 may include providing a film 710. The film includes a water-soluble polymer and an aromatic TPU. As described herein, the water-soluble polymer may be substantially crystalline. For example, the water-soluble polymer may have a crystallinity greater than 50%, such as greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, or greater than 90%. In some embodiments, the water-soluble polymer may include polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelling starch, nylon copolymer, polyacrylic acid, and mixtures thereof. In some embodiments, the aromatic TPU may have a tensile strength ranging from 10 MPa to 50 MPa. In some embodiments, the aromatic TPU may have a tensile modulus ranging from 1 MPa to 5 MPa.

[0149] Method 700 can include bonding a portion of the film to a substrate 720. For example, the film can be bonded to at least one substrate to produce a laminate (e.g., a liner). The film can be bonded to at least one substrate (top and / or bottom) to control lateral expansion and closure of an aperture used as a valve. In some embodiments, the film is bonded to any layer of an absorbent article. For example, the film can be bonded to one or more fluid transfer layers, an absorbent body, or a backsheet.

[0150] In some embodiments, method 700 may include cutting or scoring the laminate 730. In some embodiments, the laminate is punched, scored, or cut to include one or more holes. For example, the laminate may be laser cut to include Figure 2 A to Figure 4FAny valve design described in . In some embodiments, the membrane can be cut before bonding the membrane to the substrate. In some embodiments, the membrane and the substrate are bonded to produce a laminate, and the laminate can be cut or punched to include one or more holes.

[0151] In some embodiments, the laminate may be patterned to leave specific unbonded areas adjacent to one or more holes of the membrane. For example, Figure 7B The embodiment of laminate 750 including multiple holes 760 is shown. The area around hole 760 can be an unbonded area 770 of film. For example, unbonded area 770 is not bonded to substrate. When in contact with water, the unbonded area 770 of film allows film to expand laterally to close the hole. The amount of expansion (for example, lateral expansion) may be affected by the composition of film, the ratio of water-soluble polymer to thermoplastic polyurethane and the amount of fluid in contact with thin film.

[0152] Example

[0153] Two sample absorbent articles were tested to determine the water responsiveness properties of each absorbent article. The two absorbent articles included a laminate comprising a control film and a prototype film. The prototype film contained 70% by weight of POLYOX TM WSR N-80 (polyethylene oxide, a water-soluble polymer) and 30 wt% WHT-F170 (an aromatic thermoplastic polyurethane). The prototype film had a crystallinity of 56% as measured by DSC analysis. The prototype film was bonded to a hydrophobic spunbond nonwoven to produce a laminate. The laminate was cut into a valve design including a bull's-eye shape. The prototype absorbent article included a surge material and a core underneath the laminate, completing the construction of the prototype absorbent article. The core included fluff and superabsorbent material.

[0154] The control film comprises 100 wt% WANTHANE WHT-F170. The control film is bonded to a hydrophobic spunbond nonwoven material to produce a laminate. The laminate is cut into a valve design including a bull's-eye shape. The control absorbent article comprises a surge material and a core below the laminate, thereby completing the construction of the control absorbent article. The core comprises fluff and superabsorbent material.

[0155] Each absorbent article was tested to determine the water responsiveness properties of the film. The absorbent articles were tested using a modified flat suction test. The modified flat suction test involves insulting the absorbent article twice with 85 ml of a 0.9 wt % NaCl aqueous solution. The absorbent article was subjected to the first insult of 85 ml of solution for two minutes. The absorbent article was then rewetted (under pressure) on blotting paper for two minutes. After an eight minute waiting period, the absorbent article was subjected to a second insult of 85 ml of solution, and after two minutes, the rewet measurement was repeated.

[0156] Fig. 8A and Figure 8B The expansion and contraction characteristics of a prototype absorbent article including a bulls-eye pattern according to some embodiments of the present invention are shown. Fig. 8A and Figure 8B Two photographs are provided showing the prototype absorbent article 805 before insult 800 and after insult 850. The circular arcs outline the border between the film edge 810 and the hole 820 of the laminate. The photographs show that before insult 800, the space between the film edge 810 defining the hole 820 of the bull's eye design was clearly separated by 1 mm or 2 mm. However, after insult 850, the arcs became closer, indicating that when wet, the film of the laminate has expanded and closed the hole 820 in the valve of the prototype absorbent article 805.

[0157] The results of the improved intake and rewet tests are shown in Table 3. Although there was little difference between the prototype and control data for both intake times, the prototype with the membrane described herein showed an advantage over the control by significantly reducing rewet in both insults.

[0158]

[0159] All patents, publications and abstracts cited above are incorporated herein by reference in their entirety. In order to achieve the various objectives of the present invention, various embodiments of the present invention have been described. It should be appreciated that these embodiments are merely illustrations of the principles of the present invention. It will be apparent to those skilled in the art that various modifications and adjustments may be made thereto without departing from the spirit and scope of the present invention as defined in the appended claims.

[0160] Although the present invention has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art can easily conceive of modifications, variations and equivalents of these embodiments after obtaining an understanding of the foregoing. Therefore, the scope of the present invention should be assessed as the scope of the appended claims and any equivalents thereof and the following embodiments:

[0161] Embodiment 1: An absorbent article comprising: a film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%, wherein the film is configured to expand upon contact with a fluid.

[0162] Embodiment 2: The absorbent article of any preceding or subsequent embodiment, wherein the water soluble polymer comprises polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelatinized starch, nylon copolymers, polyacrylic acid, or combinations thereof.

[0163] Embodiment 3: The absorbent article of any preceding or subsequent embodiment, wherein the water soluble polymer comprises polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelatinized starch, nylon copolymers, polyacrylic acid, or combinations thereof.

[0164] Embodiment 4: The absorbent article of any preceding or subsequent embodiment, wherein the film comprises a patterned surface having one or more apertures, wherein the apertures comprise at least 10% of the total surface area of ​​the film.

[0165] Embodiment 5: The absorbent article of any preceding or subsequent embodiment, wherein the area adjacent to the one or more apertures is treated with a hydrophilizing agent.

[0166] Embodiment 6: The absorbent article of any preceding or subsequent embodiment, wherein a portion of the film is bonded to a substrate.

[0167] Embodiment 7: The absorbent article of any preceding or subsequent embodiment, wherein the area of ​​the film adjacent the one or more apertures is not bonded to a substrate.

[0168] Embodiment 8: The absorbent article of any preceding or subsequent embodiment, wherein the aromatic thermoplastic polyurethane comprises a polyester-based thermoplastic polyurethane.

[0169] Embodiment 9: The absorbent article of any preceding or subsequent embodiment, wherein the film has a crystallinity of 25% to 60%.

[0170] Embodiment 10: The absorbent article of any preceding or subsequent embodiment, wherein the film comprises the water-soluble polymer in an amount of 10 wt% to 90 wt% based on the total weight of the film.

[0171] Embodiment 11: The absorbent article of any preceding or subsequent embodiment, wherein the film comprises the aromatic thermoplastic polyurethane in an amount of 10 wt% to 90 wt% based on the total weight of the film.

[0172] Embodiment 12: The absorbent article of any preceding or subsequent embodiment, wherein the weight ratio of water soluble polymer to the aromatic thermoplastic polyurethane is at least 1:1.

[0173] Embodiment 13: An absorbent article as described in any preceding or subsequent embodiment, wherein the film comprises the water-soluble polymer in an amount of 30 wt% to 70 wt% based on the total weight of the film, the thermoplastic polyurethane in an amount of 30 wt% to 60 wt% based on the total weight of the film, and the ratio of water-soluble polymer to aromatic thermoplastic polyurethane is at least 1.5:1.

[0174] Embodiment 14: The absorbent article of any preceding or subsequent embodiment, wherein the film comprises one or more additives comprising a surfactant, an absorbent, an antibiotic, or a skin benefit agent.

[0175] Embodiment 15: The absorbent article of any preceding or subsequent embodiment, wherein the one or more additives comprise a superabsorbent.

[0176] Embodiment 16: The absorbent article of any preceding or subsequent embodiment, wherein the absorbent article comprises a fluid transfer layer between the film and the absorbent body.

[0177] Embodiment 17: The absorbent article of any preceding or subsequent embodiment, wherein the film further comprises a 3-D structure treated with a hydrophobic agent.

[0178] Embodiment 18: An absorbent article comprising: a film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%; a substrate bonded to the film to produce a laminate; a backsheet; and an absorbent body between the laminate and the backsheet.

[0179] Embodiment 19: A method for producing a laminate, the method comprising: providing a film, wherein the film comprises a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than 25%; and bonding a portion of the film to a substrate to produce a laminate.

[0180] Embodiment 20: A method as described in any preceding or subsequent embodiment, wherein the membrane is configured to swell when in contact with body fluids.

[0181] Embodiment 21: The method of any preceding or subsequent embodiment, further comprising cutting or scoring a pattern in the laminate comprising a plurality of holes, wherein areas of the film adjacent to the holes are not bonded to the substrate.

Claims

1. An absorbent article comprising: A film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%, wherein the film is configured to expand upon contact with a fluid.

2. The absorbent article of claim 1, wherein the water-soluble polymer comprises polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine, gelatinized starch, nylon copolymer, polyacrylic acid, or a combination thereof.

3. The absorbent article of claim 1, wherein the film comprises a patterned surface having one or more apertures, wherein the apertures comprise at least 10% of the total surface area of ​​the film.

4. The absorbent article of claim 3, wherein the area adjacent to the one or more apertures is treated with a hydrophilic agent.

5. The absorbent article of claim 4, wherein a portion of the film is bonded to a substrate.

6. The absorbent article of claim 4, wherein the area of ​​the film adjacent the one or more apertures is not bonded to a substrate.

7. The absorbent article of claim 1, wherein the aromatic thermoplastic polyurethane comprises a polyester-based thermoplastic polyurethane.

8. The absorbent article of claim 1, wherein the film has a crystallinity of 25% to 60%.

9. The absorbent article of claim 1, wherein the film comprises the water-soluble polymer in an amount of 10 wt% to 90 wt% based on the total weight of the film.

10. The absorbent article of claim 1, wherein the film comprises the aromatic thermoplastic polyurethane in an amount of 10 wt% to 90 wt%, based on the total weight of the film.

11. The absorbent article of claim 1 , wherein the weight ratio of water soluble polymer to the aromatic thermoplastic polyurethane is at least 1:

1.

12. The absorbent article of claim 1, wherein the film comprises the water-soluble polymer in an amount of 30 to 70 weight percent based on the total weight of the film, the thermoplastic polyurethane in an amount of 30 to 60 weight percent based on the total weight of the film, and the ratio of the water-soluble polymer to the aromatic thermoplastic polyurethane is at least 1.5:

1.

13. The absorbent article of claim 1, wherein the film comprises one or more additives, the one or more additives comprising surfactants, absorbents, antibiotics, or skin benefit agents.

14. The absorbent article of claim 13, wherein the one or more additives include a superabsorbent.

15. The absorbent article of claim 1 further comprising a fluid transfer layer between the film and the absorbent body.

16. The absorbent article of claim 1, wherein the film further comprises a 3-D structure treated with a hydrophobic agent.

17. An absorbent article comprising: A film comprising a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than or equal to 25%; a backsheet; and An absorbent body is provided between the film and the backsheet.

18. A method of producing a laminate, the method comprising: Providing a film, wherein the film comprises a water-soluble polymer and an aromatic thermoplastic polyurethane, wherein the film has a crystallinity greater than 25%; and A portion of the film is bonded to a substrate to produce a laminate.

19. The method of claim 18, wherein the membrane is configured to swell upon contact with bodily fluids.

20. The method of claim 18, further comprising cutting or scoring a pattern in the laminate comprising a plurality of holes, wherein areas of the film adjacent to the holes are not bonded to the substrate.

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