Film and article containing said film

Abstract

The resulting film is substantially void-free and has a variety of appearances for articles such as clothing into which the film is incorporated. [Solution] A film comprising: A) a microporous polyethylene membrane, the microporous polyethylene membrane comprising polyethylene, the polyethylene having a weight average molecular weight greater than 500,000 grams / mole, the microporous polyethylene membrane having a porosity of at least 40 volume percent, and the microporous polyethylene membrane having a Gurley number of less than 200 seconds; and B) a hydrophilic polymer, a portion of the hydrophilic polymer present inside at least some of the pores of the microporous polyethylene membrane, and at least a portion of the hydrophilic polymer forming a cap layer present on at least one surface of the microporous polyethylene membrane, the cap layer being substantially void-free.

Description

[Technical Field]

[0001] The present disclosure relates to waterproof and breathable films and articles comprising the films that are useful in a variety of applications. The films can be used alone or laminated with other layers to form multi-layer laminates. [Background technology]

[0002] Apparel and other types of clothing, such as shoes, gloves, and hats, often incorporate a waterproof and breathable layer to keep the wearer dry in wet conditions. These garments can be formed using a laminate of a breathable, waterproof layer and one or more textiles. Waterproof and breathable composite films made using porous PTFE membranes and hydrophilic polyurethanes are currently used to manufacture textile laminates, such as those marketed under the trade name GORE-TEX® by W.L. Gore & Associates of Newark, Delaware. PTFE membranes are microporous and generally hydrophobic, with pore sizes larger than individual water molecules but much smaller than water droplets. Water vapor can pass through the material, but water droplets are prevented from passing from one side of the membrane to the other.

[0003] While PTFE microporous membranes work well, porous polyurethane membranes have also been developed for use in clothing. However, these membranes can lack durability and, in some cases, can be dissolved by certain commonly used products, such as nail polish or insect repellent. These membranes can also have limitations, such as being stiff and noisy when the wearer moves.

[0004] Composite membranes in which porous membranes such as polyethylene are coated with hydrophilic polymers have also been investigated, but the following concerns remain: For example, porous materials such as polyethylene have relatively low heat resistance, making it difficult to select a hydrophilic polymer or its curing agent with a high reaction temperature (e.g., curing temperature) when considering the process temperature between them. Furthermore, the coated hydrophilic polymer and curing agent may react with moisture (or humidity) in the air, or the curing agent may undergo a chemical reaction, resulting in the generation of gases. These gases may affect the surface properties (e.g., appearance) of the coating. Summary of the Invention [Problem to be solved by the invention]

[0005] There remains a need to produce films (substantially void-free) that have a variety of appearances for articles such as clothing into which the films are incorporated. [Means for solving the problem]

[0006] The present disclosure relates to a first embodiment that is a film, the film comprising: A) Below: i) a weight average molecular weight greater than 500,000 grams / mole; ii) a porosity of at least 40% by volume; iii) Gurley number less than 200 seconds a microporous polyethylene membrane having B) a hydrophilic polymer, at least a portion of which is present within at least some of the pores of the microporous polyethylene membrane, and comprising a cap layer, at least a portion of which is present on at least one surface of the microporous polyethylene membrane, the cap layer being substantially void-free; Includes.

[0007] The present disclosure also relates to articles comprising at least one film.

[0008] In a second embodiment, the present disclosure relates to the film of embodiment 1, wherein substantially all of the pores of the microporous polyethylene membrane are filled with a hydrophilic polymer.

[0009] In a third embodiment, the present disclosure relates to the film of either embodiment 1 or 2, wherein the film further comprises a release layer, the release layer being adjacent to the cap layer.

[0010] In a fourth embodiment, the present disclosure relates to the film of any of embodiments 1 to 3, wherein the cap layer has a controlled surface morphology.

[0011] In a fifth embodiment, the present disclosure relates to the film of any of embodiments 1 to 4, wherein the controlled surface morphology comprises a surface that is transfer printed from a release layer disposed on the cap layer.

[0012] In a sixth embodiment, the present disclosure relates to the film of any of the first to fifth embodiments, wherein the film has an opacity of 10-85.

[0013] In a seventh embodiment, the present disclosure relates to the film of any of the first to sixth embodiments, wherein the film has a heat resistance of 190° C. or less.

[0014] In an eighth embodiment, the present disclosure relates to the film of any of the first to seventh embodiments, wherein the film has a tensile strength in the MD direction of 0.45 kgf or more.

[0015] In a ninth embodiment, the present disclosure relates to the film of any of the first to eighth embodiments, having a tensile strength in the TD direction of 0.36 kgf or greater.

[0016] In a tenth embodiment, the present disclosure relates to the film of any of the first to ninth embodiments, wherein the hydrophilic polymer comprises a polyurethane, a polyamide, a polyester, an epoxy resin, a silicone resin, an ionomer, or a copolymer thereof, or a combination thereof.

[0017] In an eleventh embodiment, the present disclosure relates to the film of any of the first to tenth embodiments, wherein the film has a Gurley number of 1000 seconds or greater.

[0018] In a twelfth embodiment, the present disclosure relates to the film of any of the first to eleventh embodiments, wherein the film has a surface gloss of 3.0 gloss units or greater.

[0019] In a thirteenth embodiment, the present disclosure provides the film of any of the first to twelfth embodiments, wherein the film has a viscosity of 2500 g / m 2 / day or more.

[0020] In a fourteenth embodiment, the present disclosure relates to an article comprising the film of any of the first to thirteenth embodiments.

[0021] In some embodiments, the film comprises: A) a microporous polyethylene membrane, wherein the microporous polyethylene membrane comprises polyethylene, the polyethylene having a weight average molecular weight greater than 500,000 grams / mole, the microporous polyethylene membrane has a porosity of at least 40% by volume, and the microporous polyethylene membrane has a Gurley number of less than 200 seconds; and B) a hydrophilic polymer, wherein a portion of the hydrophilic polymer is present within at least some of the pores of the microporous polyethylene membrane, and at least a portion of the hydrophilic polymer forms a cap layer present on at least one surface of the microporous polyethylene membrane, wherein the cap layer is substantially void-free.

[0022] In some embodiments, the hydrophilic polymer within the microporous polyethylene membrane fills substantially all of the pores of the microporous polyethylene membrane.

[0023] In some embodiments, the film also includes a release layer, the release layer being adjacent to the cap layer.

[0024] In some embodiments, the cap layer has a controlled surface morphology, hi some embodiments, the controlled surface morphology comprises a transfer printed surface from a release layer disposed on the cap layer.

[0025] In some embodiments, the film has an opacity of 10-85.

[0026] In some embodiments, the film has a heat resistance of 190° C. or less.

[0027] In some embodiments, the film has a tensile strength in the MD direction of 0.45 kgf or greater.

[0028] In some embodiments, the film has a tensile strength in the TD direction of 0.36 kgf or greater.

[0029] In some embodiments, the hydrophilic polymer comprises a polyurethane, a polyamide, a polyester, an epoxy resin, a silicone resin, an ionomer, or a copolymer thereof, or a combination thereof.

[0030] In some embodiments, the film has a Gurley number of 1000 seconds or greater.

[0031] In some embodiments, the film has a surface gloss of 3.0 gloss units or greater.

[0032] In some embodiments, the film has a thickness of 2500 g / m 2 / day or more water vapor transmission rate.

[0033] In some embodiments, the article comprises any of the films described above. [Effects of the Invention]

[0034] The film has a cap layer that is substantially free of voids, and the hydrophilic polymer fills at least a portion of the pores of the porous polyethylene film, thereby reducing diffuse reflection of light due to the voids, making it easy to achieve a desirable appearance. Furthermore, it is easy to control the surface morphology of the cap layer of the film. Furthermore, it is easy to achieve excellent waterproofness and breathability. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 shows a scanning electron micrograph (SEM) of a film including a conventional cap layer, where the cap layer contains voids and has surface irregularities.

[0036] [Figure 2] FIG. 1 shows an SEM of a cap layer according to one embodiment of the present invention, where the cap layer does not have voids.

[0037] [Figure 3A] FIG. 10 shows an SEM of the relatively smooth surface morphology of the release layer.

[0038] [Figure 3B] FIG. 10 shows the surface morphology of the cap layer after removing the release layer.

[0039] [Figure 4A] FIG. 10 shows an SEM of the relatively rough surface morphology of the release layer.

[0040] [Figure 4B] FIG. 10 shows the surface morphology of the cap layer after removing the release layer.

[0041] [Figure 5] FIG. 1 shows an SEM of the surface morphology of the cubic pattern transferred from the surface of the release layer. DETAILED DESCRIPTION OF THE INVENTION

[0042] The entire disclosures of all cited patent and non-patent publications are incorporated herein by reference.

[0043] As used herein, the terms "embodiment" or "disclosure" are not intended to be limiting and apply generally to any embodiment defined in the claims or described herein. These terms are used interchangeably herein.

[0044] Additionally, the term "based on" is not exclusive and allows for based on additional unrecited elements unless the context clearly dictates otherwise. Additionally, throughout this specification, the meanings of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0045] The features and advantages of the present disclosure will be readily understood by those skilled in the art by consideration of the following detailed description. It will be understood that certain features of the present disclosure, which are, for clarity, described above and below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure, which are, for brevity, described in combination in the context of a single embodiment, may also be provided separately or in any subcombination. Furthermore, unless the context dictates otherwise, references to the singular may also include the plural (e.g., "a" and "an" may refer to one or more).

[0046] The use of numerical values ​​in the various ranges specified in this application, unless expressly stated otherwise, is stated as an approximation, with the word "about" preceding both the minimum and maximum values ​​within the stated range. As such, slight variations above or below the stated range can be used to achieve results that are approximately the same as values ​​within the stated range. Also, the disclosure of these ranges is intended as a continuous range, including all values ​​between the minimum and maximum values.

[0047] As used herein, the term "membrane" refers to a polymer in the form of a substantially two-dimensional sheet, in which the length and width are much greater than the thickness, e.g., both the length and width are at least 100 times the thickness. In some embodiments, the membrane is microporous, e.g., having a structure that allows water vapor to pass through the thickness of the membrane, but liquid water cannot penetrate from one side of the membrane to the other. On average, the pore size is on the order of a few nanometers to about 1 micrometer.

[0048] The term "film" refers to a membrane whose pores are at least partially filled with a polymer such that gas or liquid flow does not occur through the open pore channels within the membrane. In some embodiments, the polymer that at least partially fills the pores may be a hydrophilic polymer.

[0049] The term "hydrophilic polymer" refers to a polymer that is capable of transporting significant amounts of water through a film by absorbing water on one side of the film where the water concentration is higher and desorbing or evaporating the water on the opposite side of the film where the water vapor concentration is lower. In some embodiments, a 10 micrometer thick hydrophilic polymer layer has a water content of 5,000 g / m 2 / day or more, or 10,000g / m 2 It can have a water vapor transmission rate of 1 / day or more.

[0050] The terms "microporous polyethylene membrane," "porous polyethylene membrane," and "polyethylene membrane" are used interchangeably throughout this specification. Unless otherwise specified, these terms refer to a microporous polyethylene membrane having i) a weight average molecular weight greater than 500,000 g / mol, ii) a porosity of at least 40%, and iii) a Gurley number less than 200 seconds. Under magnification, the porous polyethylene membrane exhibits a fibril structure of polyethylene fibrils, where, under sufficient magnification, one or more polyethylene fibrils are visible, and optionally, three or more fibrils may be interconnected by one or more intersections of three or more fibrils.

[0051] As used herein, the term "polyethylene" refers to a polyethylene polymer that contains less than 5% by weight of one or more copolymers. In some embodiments, the polyethylene does not contain any fluorine-containing copolymers, and in yet other embodiments, the polyethylene is a polyethylene homopolymer.

[0052] The present disclosure relates to a film comprising: A) a microporous polyethylene membrane; and B) a hydrophilic polymer, at least a portion of which fills at least a portion of the pores of the porous polyethylene membrane, referred to as a cap layer present on at least one surface of the microporous polyethylene membrane, the cap layer being substantially void-free. The film can be leak-resistant due to contamination with oil, detergent, or other contact angle-reducing materials, and is therefore waterproof. Furthermore, articles including the film can exhibit greater outdoor and laundering durability than other non-breathable hydrophilic films that do not include a porous polyethylene membrane as a structural support. The porous polyethylene membrane can have a weight-average molecular weight greater than 500,000 grams / mole (g / mol) (e.g., can be formed from polyethylene having a weight-average molecular weight greater than 500,000 grams / mole (g / mol)). In some embodiments, the porous polyethylene membrane can have a weight average molecular weight greater than 750,000 g / mol (e.g., can be formed from polyethylene having a weight average molecular weight greater than 750,000 grams / mole (g / mol)). In yet other embodiments, the porous polyethylene membrane can have a weight average molecular weight greater than 1,000,000 g / mol (e.g., can be formed from polyethylene having a weight average molecular weight greater than 1,000,000 grams / mole (g / mol)). In yet other embodiments, the polyethylene membrane can have a weight average molecular weight greater than 1,500,000 grams / mole or greater than 1,750,000 grams / mole (e.g., can be formed from polyethylene having a weight average molecular weight greater than 1,500,000 grams / mole (g / mol) or greater than 1,750,000 grams / mole (g / mol)).In yet another embodiment, the polyethylene film has a weight average molecular weight greater than 2,000,000 grams / mole, 3,000,000 grams / mole, 4,000,000 grams / mole, 5,000,000 grams / mole, or greater than 8,000,000 grams / mole (e.g., can be formed from polyethylene having a weight average molecular weight greater than 2,000,000 grams / mole (g / mol), or greater than 3,000,000 grams / mole, or greater than 4,000,000 grams / mole, or greater than 5,000,000 grams / mole, or greater than 8,000,000 grams / mole).

[0053] A microporous polyethylene membrane refers to a porous polyethylene membrane having a porosity of at least 40% by volume. In some embodiments, the porosity of the porous polyethylene membrane may be at least 50% by volume, or at least 60% by volume, or at least 70% by volume, or at least 80% by volume. The porosity (f) of the membrane can be calculated by measuring the mass per unit area (MPA) of the membrane and the thickness (t) of the membrane using the relationship (f = (1 - MPA / (t × p)) × 100), where p is the density of the membrane polymer. The porous polyethylene membrane can also have a Gurley number of less than 200 seconds, or less than 100 seconds, or 90 seconds or less, or 80 seconds or less, or 70 seconds or less, or 60 seconds or less, or 50 seconds or less, or 40 seconds or less, or less than 10 seconds.

[0054] The microporous polyethylene membrane may be relatively lightweight, for example, 10 grams per square meter (gsm) or less. In other embodiments, the porous polyethylene membrane may have a weight of 9 gsm or less, or 8 gsm or less, or 7 gsm or less, or 6 gsm or less, or 5 gsm or less, or 4 gsm or less, or 3 gsm or less, or 2 gsm or less.

[0055] The microporous polyethylene film may or may not be colored. The use of a porous polyethylene film can provide valuable aesthetic qualities to films and articles containing the film, especially if the porous polyethylene film is visible in the article. Any known coloring method can be used. For example, the porous polyethylene film can be colored throughout the bulk of the film by adding a pigment or dye during the film formation process. In other embodiments, the porous polyethylene film can be colored after formation using known printing and dyeing processes. In yet other embodiments, the porous polyethylene film can be free or substantially free of added color, and color can be added at one or more steps during the film formation process described herein.

[0056] The film also includes a hydrophilic polymer that fills at least a portion of the pores of the microporous polyethylene membrane. The phrase "filling at least a portion of the pores" means that the hydrophilic polymer is absorbed into the pores of the polyethylene membrane to the extent that airflow cannot be measured through the region of the film containing the hydrophilic polymer (Gurley number of 1000 seconds or greater). In other words, the hydrophilic polymer is not simply coated on the walls of the polyethylene membrane that define the pores. Although some voids may be present, the hydrophilic polymer is believed to form a continuous layer within the region of the porous polyethylene membrane to which the hydrophilic polymer is applied. In other embodiments, the hydrophilic polymer forms a continuous layer that is free of, or substantially free of, voids within the region of the porous polyethylene membrane to which the hydrophilic polymer is applied. In yet another embodiment, substantially all of the pores of the porous polyethylene membrane are filled with the hydrophilic polymer. The hydrophilic polymer can fill the entire microporous polyethylene membrane, extending through the thickness of the membrane to the edges of the membrane.

[0057] As used herein, the terms "substantially" or "nearly" are defined as generally corresponding to, but not necessarily completely corresponding to (and including), the specified content, as understood by those skilled in the art, and within a range appropriate for achieving the intended purpose or function.

[0058] For example, "substantially free of voids" can mean that the area ratio of voids in cross-sectional observation is a few percent or less, for example, 1% or less, 2% or less, 3% or less, 4% or less, 5% or less, 6% or less, 7% or less, 8% or less, 9% or less, or 10% or less. Furthermore, "nearly all pores are filled" can mean that the area ratio of unfilled pores in cross-sectional observation is a few percent or less, for example, 1% or less, 2% or less, 3% or less, 4% or less, 5% or less, 6% or less, 7% or less, 8% or less, 9% or less, or 10% or less.

[0059] The polyethylene membrane has a first surface and a second surface. A hydrophilic polymer can be applied to the first surface of the porous polyethylene membrane, and the hydrophilic polymer can penetrate at least some of the pores to form a film, thereby filling at least some of the pores of the polyethylene membrane. Furthermore, the first surface of the polyethylene membrane includes a cap layer of hydrophilic polymer on the exterior of the membrane. The hydrophilic polymer constituting the cap layer is the same hydrophilic polymer as the hydrophilic polymer present inside (or filling) at least some of the pores of the polyethylene membrane. However, the hydrophilic polymers are present in different locations. Furthermore, the hydrophilic polymers are interconnected, e.g., interconnected through the first surface of the porous polyethylene membrane. There is essentially no upper limit to the cap layer or amount of hydrophilic polymer present on the first surface of the porous polyethylene membrane.

[0060] However, if the cap layer is too thick, the beneficial properties of the porous polyethylene membrane (e.g., lightweight, etc.) cannot be realized, so the upper cap thickness is about 50 micrometers. In some embodiments, the cap layer of hydrophilic polymer can be up to 40 micrometers, or up to 30 micrometers, or up to 20 micrometers, or up to 15 micrometers thick on the first surface of the polyethylene membrane. In some embodiments, the cap layer of hydrophilic polymer can be up to about 10 micrometers thick on the first surface of the polyethylene membrane. In other embodiments, the cap layer on the first surface of the polyethylene membrane is 10 micrometers or less, or 8 micrometers or less, or 6 micrometers or less, or 4 micrometers or less, or 2 micrometers or less thick. The second surface of the polyethylene membrane can be substantially free of hydrophilic polymer on its surface, for example, the surface of the polyethylene membrane can be free of hydrophilic polymer greater than 1 micrometer thick. In some embodiments, less than the entire thickness of the porous polyethylene membrane is filled with the hydrophilic polymer, for example, up to 90% of the thickness of the polyethylene membrane can be filled with the hydrophilic polymer, provided that sufficient hydrophilic polymer is absorbed to provide a porous polyethylene film having a Gurley number of 1000 seconds or greater. In other embodiments, substantially the entire thickness of the porous polyethylene membrane is filled with the hydrophilic polymer. As used herein, the phrase "substantially the entire thickness" means that at least 90% of the thickness of the porous polyethylene membrane is filled with the hydrophilic polymer.

[0061] In some embodiments, the hydrophilic polymer can be applied continuously to the porous polyethylene membrane such that substantially 100% of the surface area of ​​the porous polyethylene membrane comprises the hydrophilic polymer. As used in this context, the term "continuously" means that the entire width, or approximately the entire width, of the porous polyethylene membrane is coated with the hydrophilic polymer.

[0062] It should be noted that many coating processes do not allow for coating the entire width of the membrane due to edge frames or weirs, so the edges of the roll of material may not be coated. In other embodiments, the hydrophilic polymer may be applied to the porous polyethylene membrane in a discontinuous manner. As used in this context, the term "discontinuous" means that less than 100 percent of the surface area of ​​the porous polyethylene membrane is coated with the hydrophilic polymer, and some of the non-edge regions of the porous polyethylene membrane are free of the hydrophilic polymer. For example, if the hydrophilic polymer is applied to the porous polyethylene membrane as a series of dots or a grid of orthogonal lines, these can be considered a discontinuous coating. The percent area of ​​the porous polyethylene membrane filled with the hydrophilic polymer may range from 20 percent to 100 percent, or from 30 percent to less than 100 percent, or from 40 percent to less than 100 percent, or from 50 percent to less than 100 percent, or from 60 percent to less than 100 percent, or from 70 percent to less than 100 percent, or from 80 percent to less than 100 percent, or from 90 percent to less than 100 percent. In other embodiments, the hydrophilic polymer can be applied to generate random or non-random patterns of points, polygons, parallel lines, intersecting lines, straight lines, curved lines, or any combination thereof, thereby providing the desired area coverage. If oleophobicity is desired for such films, it may be desirable in certain embodiments to include an oleophobic coating, as described elsewhere herein.

[0063] As a weight ratio, the film can have a ratio of the weight of hydrophilic polymer (which fills at least a portion of the pores of the microporous polyethylene membrane and forms the cap layer) to the weight of the porous polyethylene membrane ranging from 30.0 to 0.5. In other embodiments, the weight ratio of hydrophilic polymer to polyethylene membrane can be 20.0, 15.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, or any weight ratio therebetween.

[0064] Suitable hydrophilic polymers can include, for example, polyurethane, polyamide, polyester, epoxy resin, silicone resin, ionomer, or copolymer thereof, or a combination thereof. In other embodiments, virtually any suitable hydrophilic polymer can be used as long as it has a water vapor transmission rate of 5,000 grams / square meter / day or more, or 10,000 grams / square meter / day or more. The hydrophilic polymer can be a thermoplastic or a crosslinkable polymer. In some embodiments, the hydrophilic polymer is a polyurethane, and in further embodiments, the polyurethane is a crosslinked polyurethane. Suitable polyurethane polymers can be, for example, polyester urethane, polyether urethane, or polyether-polyester urethane. Hydrophilic polymers can be produced or obtained by known methods. For example, the methods taught in U.S. Patent Application Publication No. 2020 / 013426 and Japanese Patent Application Laid-Open No. 2002-069370 are incorporated herein by reference in their entirety. All of these documents teach methods for obtaining conventional hydrophilic polymers, and these teachings can be applied to obtaining the hydrophilic polymers of the present disclosure.

[0065] In some embodiments where coloring is desired, color can be imparted using a pre-colored hydrophilic polymer, for example, by adding a pigment or dye to the hydrophilic polymer, resulting in a film with the desired color. In other embodiments, the porous polyethylene film can be colored during the formation of the porous polyethylene film using known methods, such as a masterbatch process. Thus, one or both of the porous polyethylene film and the hydrophilic film can be colored or uncolored. When both the porous polyethylene film and the hydrophilic polymer are colored, they can be colored in the same or similar shades, or the colors can be selected independently of each other. Any known pigment or dye can be used, including organic pigments and dyes, inorganic pigments and dyes, metals, metal oxides, carbon black, titanium dioxide, or combinations thereof.

[0066] In yet another embodiment, the porous polyethylene membrane can be treated with both an oleophobic polymer and a hydrophilic polymer. For example, in a first step, a first surface of the porous polyethylene membrane can be treated with an oleophobic polymer that can coat the walls defining the pores of the porous polyethylene membrane without filling the pores, and the oleophobic polymer is provided so that less than the entire thickness of the porous polyethylene membrane is treated with the oleophobic polymer. After an optional step of drying and curing the oleophobic polymer, a second surface of the porous polyethylene membrane can be treated with a hydrophilic polymer to fill at least a portion of the remaining thickness of the porous polyethylene membrane, followed by an optional step of heating and curing the hydrophilic and oleophobic polymers. In these embodiments, the hydrophilic polymer cannot wet the oleophobically treated portion of the porous polyethylene membrane, and therefore only fills the portion of the porous polyethylene membrane that is not oleophobically treated.

[0067] In some embodiments, the porous polyethylene membrane can be treated with an oleophobic polymer over 5 percent or more of its thickness. In other embodiments, the porous polyethylene membrane can be treated with an oleophobic treatment over 95 percent or less of its thickness. In yet other embodiments, the oleophobic treatment can be present in a range of 10 percent to 90 percent of the thickness of the porous polyethylene membrane, or 10 percent to 80 percent of the thickness of the porous polyethylene membrane, or 10 percent to 70 percent, or 10 percent to 60 percent, or 10 percent to 50 percent, or 10 percent to 40 percent, or 10 percent to 30 percent, or 10 percent to 20 percent. After treating the first side of the porous polyethylene membrane, the second side of the porous polyethylene membrane can be treated with a hydrophilic polymer, which can fill the remaining thickness of the porous polyethylene membrane, and in some embodiments, the hydrophilic polymer forms a cap layer of hydrophilic polymer.

[0068] The cap layer is present on at least one surface of the microporous polyethylene film. Therefore, the cap layer can affect the appearance of the film. The cap layer can be formed by applying a hydrophilic polymer to at least one surface of the porous polyethylene film. Generally, hydrophilic polymers can generate gases by reacting with atmospheric moisture, etc. Furthermore, when a curing agent is used to crosslink the hydrophilic polymer, gases can be generated by the reaction of the curing agent itself or the curing agent with the hydrophilic polymer. As a result, voids can remain in the cap layer after the hydrophilic polymer solidifies or hardens. The voids remaining in the cap layer can cause diffuse reflection of light, potentially resulting in surface irregularities and affecting the appearance of the film. It is often difficult to achieve the desired appearance with such films or articles containing such films. As described in more detail herein, the inventors have discovered that a substantially void-free cap layer can be obtained by covering a film comprising a porous polyethylene membrane, a hydrophilic polymer, and a cap layer with a release layer adjacent to the cap layer until the hydrophilic polymer (which may comprise the cap layer) solidifies or hardens. The release layer prevents the hydrophilic polymer filling the pores of the polyethylene film and the hydrophilic polymer constituting the cap layer from contacting atmospheric moisture, and the hydrophilic polymer solidifies or hardens by reacting with the moisture contained in the hydrophilic polymer or with moisture in contact with the opposite side of the cap layer. The type, moisture content, temperature, and viscosity of the hydrophilic polymer, as well as the moisture content and temperature of the atmosphere, can be appropriately selected to ensure sufficient time for solidification or hardening to minimize the generation and / or residual gas within the cap layer. These conditions, particularly the viscosity, can be adjusted to allow the hydrophilic polymer to easily fill at least a portion of the pores of the polyethylene membrane. It is also desirable to cover the hydrophilic polymer with a release layer as soon as possible after applying the hydrophilic polymer to the film or forming the cap layer. This is because contact with moisture and dust in the air can be suppressed.The release layer preferably does not stick to the solidified or hardened cap layer and is easily removable therefrom. The release layer may be a commercially available product.

[0069] FIG. 1 is an SEM image showing the surface state (cross-section) of a film 101 including a cap layer 102. This cap layer 102 solidifies or hardens after gas generated by the reaction of a mixture of a curing agent and a hydrophilic polymer forms voids 103 inside the cap layer 102. FIG. 2 is an SEM image showing the surface state (cross-section) of a film 201 including a cap layer 202 after the hydrophilic polymer has solidified or hardened while its reaction with moisture in the atmosphere is suppressed by the release layer. As shown in FIG. 1, voids 103 remain in the conventional cap layer 102. On the other hand, as shown in FIG. 2, no voids remain in the cap layer 202 of this embodiment. The difference in appearance depending on whether or not there are voids in the cap layer can be visually confirmed. 1 and 2 illustrate each cap layer 102 and 202 in parentheses to indicate the portion of each film 101 and 201 that constitutes the cap layer; it should be understood that the parentheses indicate the location of the cap layers 102 and 202 in the figures, and do not indicate a particular thickness of the cap layers 102 and 202. Similarly, it should be understood that the parentheses illustrating the films 101 and 201 indicate the location of the films 101 and 201 in the figures, and do not indicate a particular thickness of the films 101 and 201.

[0070] The cap layer can have a controlled surface morphology. Because the cap layer is substantially void-free, it can have a flat surface morphology. This flat morphology can be textured, embossed, or a combination thereof, thereby achieving a desired controlled surface morphology. The controlled surface morphology can include a desired surface roughness, desired dots, lines, or other shapes. The controlled surface morphology can achieve a desired appearance. In particular, a substantially void-free cap layer can reduce diffuse reflection of light, thereby enhancing the appearance characteristics achieved by the controlled surface morphology.

[0071] The controlled surface morphology may be the transfer surface of a release layer disposed on a cap layer. Because the cap layer is covered with the release layer until the hydrophilic polymer (which may comprise the cap layer) solidifies or hardens, the surface morphology of the solidified or hardened cap layer may be the transfer surface of the release layer. The surface morphology of the release layer can be adjusted to allow the cap layer to have a desired controlled surface morphology. Figures 3A, 3B, 4A, and 4B are SEM images showing the surface morphologies of the release layer and cap layer, respectively, after the release layer is removed. Figures 3A and 3B show relatively smooth surface morphologies, while Figures 4A and 4B show relatively rough surface morphologies.

[0072] The film can have an opacity of 10 to 85%. The opacity of the film is measured by the method specified in ASTM D 2805. The cap layer is substantially void-free, and the hydrophilic polymer fills at least a portion of the pores of the porous polyethylene film, thereby reducing diffuse reflection of light and achieving high transparency. The opacity can be adjusted by adjusting at least one of the controlled surface morphology of the cap layer, the pore filling rate of the porous polyethylene film with the hydrophilic polymer, the coloring of the hydrophilic polymer, and the coloring of the microporous polyethylene film. The opacity can be adjusted to 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 85, or any value between these two values.

[0073] The film can have a surface gloss of 3.0 gloss units or greater in the cap layer. The surface gloss of the cap layer can be freely adjusted depending on the needs of the intended application. Gloss measurements are performed using a BYK "Micro-TRI-μ Gloss μ" device at an angle of 85° across the width of the sample relative to the printed surface. The recorded data is the average of three individual measurements. Because the cap layer is substantially void-free and the hydrophilic polymer fills at least a portion of the pores of the porous polyethylene film, there is little diffuse reflection of light, making it easy to adjust the desired gloss. The gloss can be adjusted by adjusting at least one of the following: coloring of the hydrophilic resin, the pore filling rate of the porous polyethylene film with the hydrophilic polymer, or controlled surface morphology of the cap layer.

[0074] Generally, the polymers comprising the polyethylene films disclosed herein have one or more molecular weights reported as average molecular weights (e.g., 500,000 g / mole or greater). The actual molecular weight of an individual polymer is a distribution of molecular weights, and the actual molecular weight of an individual polymer includes portions above and below the reported average molecular weight. In the present disclosure, the breathability of a film, as determined by water vapor transmission rate, can be affected by a combination of the heat treatment process and the molecular weight of the polyethylene. For example, if a relatively large proportion of low-molecular-weight polymer is present and the thickness of the unfilled regions of the polyethylene film is too large, the heat treatment process may cause deformation, e.g., collapse, of the unfilled regions of the polyethylene film, resulting in a reduction or even loss of breathability of the film. However, if the average molecular weight of the polyethylene is sufficiently high and the molecular weight distribution is sufficiently narrow that little or no low-molecular-weight polyethylene is present, heating the film above the melting temperature of the polyethylene will not cause deformation or collapse of the polyethylene film structure, even if the polyethylene structure does not absorb a hydrophilic polymer. The heat treatment can be carried out in an oven, by passing the film through heated rolls, or by other known heat treatment methods. It should be noted that this heat treatment step, which results in a change in the mechanical properties of the film, can be carried out at any time after the polyethylene film is coated with the hydrophilic polymer and the hydrophilic polymer (which may include the polyethylene film constituting the cap layer) has solidified. That is, the heat treatment step can be carried out after the hydrophilic polymer has hardened and before or after the release layer has been peeled off, as long as the heat treatment temperature is within a temperature range that does not melt or deform the release layer. In some embodiments, the polyethylene film can be coated with the hydrophilic polymer to form a film, and then the film can be laminated to another layer. Alternatively, in other embodiments, the film can be laminated to another layer and then coated with the hydrophilic polymer. In any embodiment, the heat treatment step can be completed after the film is produced, before, during, or after forming the laminate.

[0075] A film comprising a porous polyethylene membrane and a hydrophilic polymer can be produced according to the following steps: 1) providing a porous polyethylene membrane having a weight average molecular weight greater than 500,000 g / mol, a porosity of at least 40% by volume, and a Gurley number of less than 200 seconds; 2) coating at least a portion of the porous polyethylene membrane with a hydrophilic polymer; 3) forming a cap layer composed of a hydrophilic polymer on the surface of the porous polyethylene membrane coated with the hydrophilic polymer; 4) covering the cap layer (on the opposite side of the porous polyethylene film) with a release layer; and 5) solidifying or curing the hydrophilic polymer.

[0076] In another embodiment, the film can be made according to the following process: 1) providing a porous polyethylene membrane having a weight average molecular weight greater than 500,000 g / mol, a porosity of at least 40% by volume, and a Gurley number of less than 200 seconds; 2) coating a first surface of the porous polyethylene membrane with an oleophobic polymer, thereby coating the walls defining the pores of the porous polyethylene membrane; 3) forming a film by coating the second surface of the porous polyethylene membrane with a hydrophilic polymer; 4) forming a cap layer composed of a hydrophilic polymer on the second surface of the porous polyethylene membrane; 5) covering the cap layer (on the opposite side of the porous polyethylene film) with a release layer; and 6) solidifying or curing the hydrophilic polymer.

[0077] In another embodiment, the article can be manufactured according to the following steps: 1) providing a porous polyethylene membrane having a weight average molecular weight greater than 500,000 g / mol, a porosity of at least 40% by volume, and a Gurley number of less than 200 seconds; 2) forming a film by coating at least a portion of a porous polyethylene membrane with a hydrophilic polymer; 3) forming a cap layer composed of a hydrophilic polymer on the surface of the porous polyethylene membrane coated with the hydrophilic polymer; 4) covering the cap layer (on the opposite side of the porous polyethylene film) with a release layer; 5) solidifying or curing the hydrophilic polymer; and 6) Laminating the film to at least one other layer.

[0078] In another embodiment, the article can be manufactured according to the following steps: 1) providing a porous polyethylene membrane having a weight average molecular weight greater than 500,000 g / mol, a porosity of at least 40% by volume, and a Gurley number of less than 200 seconds; 2) laminating at least one other layer onto the first surface of the porous polyethylene film; 3) coating at least a portion of the second surface of the porous polyethylene membrane with a hydrophilic polymer; 4) forming a cap layer composed of a hydrophilic polymer on the second surface of the porous polyethylene membrane; 5) covering the cap layer (on the opposite side of the porous polyethylene film) with a release layer; and 6) solidifying or curing the hydrophilic polymer.

[0079] Optionally, any of the above methods may include the following process embodiments: A hydrophilic polymer (e.g., polyurethane, etc.) can be laminated onto a porous polyethylene film at room temperature, and the composite can be left at room temperature in the presence of sufficient moisture in the atmosphere. Any process, such as a coating method, can be used for lamination. This process can be carried out at room temperature, low temperature, or high temperature as long as the hydrophilic polymer is curable, thereby producing a composite. If necessary, a release layer can be laminated onto the coated surface of the composite. The composite can be left under conditions of temperature (low temperature-room temperature-high temperature) and a predetermined, adjustable level of humidity to cure the hydrophilic polymer within the composite. The thickness of the cap layer is adjusted by the amount of hydrophilic polymer applied, as described in U.S. Patent Application Publication No. 2021317276.

[0080] The resulting film, which contains a porous polyethylene membrane and a hydrophilic polymer that fills the membrane pores and constitutes the cap layer, has a water resistance of 2500 grams per square meter per day (g / m 2 / day); a moisture vapor transmission rate (MVTR) of 2500 g / m² or greater; a weight of less than 30 grams per square meter, and optionally a Gurley number of 1000 seconds or greater. To be breathable, i.e., to allow water vapor to move from one side of the film to the other without liquid water passing through the film, an MVTR of 2500 g / m² or greater is required. 2 / day or more. In another embodiment, the film has a coating density of 3000 g / m 2 / day or more, 3500g / m 2 / day or more, 4000g / m 2 / day or more, 4500g / m 2 / day or more, 5000g / m 2 / day or more, 5500g / m 2 / day or more, 6000g / m 2 / day or more, 6500g / m 2 / day or more, 7000g / m 2 / day or more, 7500g / m 2 / day or more, 8000g / m 2 / day or more, 8500g / m2 / day or more, 9000g / m 2 / day or more, 9500g / m 2 / day or more, or 10,000g / m 2 can have an MVTR of 1 / day or more.

[0081] The film may also have a matrix tensile strength ratio in two orthogonal directions ranging from 0.5 to 2.0. In other embodiments, the ratio of the tensile strengths in the two orthogonal directions may range from 0.7 to 1.4. In yet other embodiments, the tensile strength ratio may be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, or any value between these two numbers. The difference in tensile strength in the two orthogonal directions is primarily due to the difference in the total strain applied in the two directions during the membrane manufacturing process.

[0082] The film may have a heat resistance of 190°C or less. In other embodiments, the heat resistance may be 180°C or less, 170°C or less, 160°C or less, 150°C or less, 140°C or less, 130°C or less, or 120°C or less. Here, heat resistance means that when the material is held at a predetermined temperature for 60 seconds, there is little deformation due to thermal contraction or expansion. For example, the change in area may be within 5%, 10%, 15%, or 20%.

[0083] The film may have a tensile strength in the MD (machine direction) of 0.45 kgf or greater. In other embodiments, the tensile strength may be 0.50 kgf or greater, 0.54 kgf or greater, 0.59 kgf or greater, or 0.63 kgf or greater.

[0084] The film may have a tensile strength in the TD (transverse) direction of 0.36 kgf or greater. In other embodiments, the tensile strength may be 0.41 kgf or greater, 0.45 kgf or greater, 0.50 kgf or greater, or 0.54 kgf or greater.

[0085] The film can also be stain-resistant due to the presence of a hydrophilic polymer, which fills the voids in at least a portion of the membrane thickness, thereby forming a continuous layer without voids in that portion of the porous polyethylene membrane. Furthermore, the cap layer can enhance the stain resistance of the film. As used herein, stain resistance means that the film does not become stained with sweat, sebum, or oil, thereby reducing its waterproof properties over time. If at least a portion of the pores of the porous polyethylene membrane remain unfilled, stain resistance can be provided to the unfilled pores by applying an oleophobic coating to the walls of the unfilled pores.

[0086] The present disclosure also relates to an article comprising the film. One advantage of an article comprising the film of the present disclosure is that it has less diffuse reflection of light than a film comprising a voided cap layer, making it easier to achieve a desired appearance. When the film is in the form of a laminate, a laminate comprising a substantially void-free cap layer and a hydrophilic polymer that fills at least a portion of the pores of a microporous polyethylene film can easily achieve a desired variety of appearances, compared to a laminate of a film having a voided cap layer. In a laminate configuration, in certain embodiments, other components within the laminate can also contribute to a variety of appearances.

[0087] The article may be a laminate, for example, by laminating one or more layers of film together with one or more other layers to form a laminate. The other one or more layers may be a textile layer, a polymer layer, a natural leather layer, a synthetic leather layer, a fleece layer, or a combination thereof. In some embodiments, the article may be a two-layer laminate including a textile layer adhered to a first side or a second side of the film. In some embodiments, the article may be a three-layer laminate including a first textile layer adhered to a first side of the film and a second textile layer adhered to a second side of the film. In yet other embodiments, additional layers may be applied to produce laminates having four, five, six, or more layers. Suitable textile layers may include any of woven, knit, or nonwoven textiles. The textile may be a natural and / or synthetic textile, such as cotton, wool, silk, jute, polyamide, polyester, acrylic, aramid, viscose, rayon, carbon fiber, or a combination thereof. Suitable polymer layers may include, for example, polyolefins, polyesters, polyamides, polyurethanes, polyvinyl alcohol, polyvinyl acetate, fluoropolymers, polyvinyl halides, polyvinyl chloride, epoxy resins, silicone polymers, or a combination thereof. Laminates may also be produced that include one or more layers of the disclosed films, one or more textile layers, and / or one or more polymer layers.

[0088] Because the disclosed films can have high strength, laminates can be made using any of the textiles or materials listed above that have a relatively low weight. In some embodiments, the laminates can include relatively low-weight textiles having a basis weight ranging from 5 grams per square meter to 30 grams per square meter (gsm). In other embodiments, the textiles can have a weight of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 gsm, or any value between two of these values. While relatively low-weight textiles can be used, textiles weighing 30 gsm or more can also be used. For example, relatively high-weight textiles, up to 500 gsm, can be used.

[0089] Lamination techniques are well known in the art and may include, for example, adhesive lamination and thermal bonding. In some embodiments, lamination is achieved by adhesive lamination, in which an adhesive is applied to one or more layers to be joined together, and then the layers are placed together, for example, by nip rollers, optionally with the application of heat and / or pressure. The adhesive can be applied to the film layer, the textile layer, or both the film layer and the textile layer. The adhesive can be applied discontinuously, for example, as a series of adhesive dots, shapes, lines, or combinations thereof. In other embodiments, the adhesive can be applied as a continuous layer of adhesive. The adhesive composition can be a thermoplastic or crosslinkable adhesive in certain embodiments. In yet another embodiment, a hydrophilic polymer can be used as the adhesive material for forming the laminate. For example, a hydrophilic polymer can be applied to one side of a porous polyethylene film to form a cap layer of the hydrophilic polymer, followed by application of a textile to the hydrophilic polymer and application of heat and / or pressure to the laminate to ensure that the hydrophilic polymer adequately contacts and adheres to the textile. When a hydrophilic polymer is used as an adhesive in a laminate, the curing step of the hydrophilic polymer can be performed after a textile or other material is placed on the side of the film containing the hydrophilic polymer cap layer. In some embodiments, a heat press can be used to provide sufficient pressure to allow the hydrophilic polymer to flow into the spaces between the textile fibers, and the heat from the heat press can perform the desired curing and heat treatment steps to produce the laminate. In other embodiments, one or more rollers can provide the necessary pressure and / or heat to accomplish the same task, for example, continuously. In a further embodiment, the curing step of the hydrophilic polymer can be performed by curing or hardening the hydrophilic polymer with moisture after a textile or other material is placed on the side of the film containing the hydrophilic polymer cap layer.

[0090] Stretchable and recoverable laminates can be manufactured according to known methods. For example, the methods taught in U.S. Patent No. 4,443,511, U.S. Patent No. 9,950,504, U.S. Patent No. 9,126,390, U.S. Patent No. 9,233,520, U.S. Patent No. 9,238,344, and International Publication No. WO 2018 / 67529 all teach how to impart stretchability to conventional membrane and laminate structures, and these teachings can be applied to provide stretchability to laminates including the films of the present disclosure, and the contents of these documents are incorporated herein by reference in their entirety.

[0091] The article may be, for example, a garment, an enclosure, a protective enclosure, a tent, a sleeping bag, a bivy bag, a backpack, a pack, a cover, and other similar forms that would benefit from the properties of the disclosed films. The garment may be a jacket, a coat, a shirt, pants, gloves, a hat, shoes, coveralls, or at least a portion thereof. Many articles are made from multiple panels sewn or otherwise bonded together to form a finished product. Thus, "at least a portion" of an article means that at least one panel or portion of a panel includes the disclosed film.

[0092] The articles and garments can be manufactured so that the film is on the outside of the garment, or on the inside of the garment, or so that the film is at least one of the middle layers of the garment, for example, the middle layer of a three-layer laminate. One advantage of the articles and garments including the disclosed films is that they can easily achieve a variety of appearances. Another advantage of the articles and garments is that they can be waterproof and breathable. If the article requires waterproofness or liquid protection, the seam holes can be made liquidproof by sealing them with, for example, seam tape. The seam tape can be attached to the article from the outside or inside of the article.

[0093] In embodiments in which the film is present on the exterior of the garment, i.e., in embodiments in which the film is the outermost portion of the garment, the film may be pigmented or unpigmented, textured, embossed, or a combination thereof, to achieve a desired appearance. In particular, the film has a substantially void-free cap layer, and the hydrophilic polymer fills at least a portion of the pores of the porous polyethylene film, thereby reducing diffuse reflection of light, making it easy to achieve a desired appearance. Methods for coloring the film are described herein. To emboss the film, the film can be selectively pressed randomly or non-randomly. For example, patterns, letters, words, images, sports team logos, corporate logos, or combinations thereof can be embossed into the membrane or film before treatment with the hydrophilic polymer, after treatment with the hydrophilic polymer, or both. Selective pressure application can create regions of different permeability in the film, thereby varying the breathability of the film, with the embossed regions having relatively lower breathability than the non-embossed regions. Suitable embossing methods are described in US Patent Application Publication No. 2008 / 0143012, the entire contents of which are incorporated herein by reference.

[0094] In embodiments in which the film is present on the exterior of a garment, i.e., the film is the outermost portion of the garment, at least a portion of the film can be textured. The film can be textured by treating the film with a random or non-random pattern of an abrasion-resistant polymer. The abrasion-resistant polymer can be applied as a series of dots, lines, or other shapes to provide a desired appearance and improved abrasion resistance to the outermost portion of the garment. In particular, the film has a substantially void-free cap layer, and the hydrophilic polymer fills at least a portion of the pores of the porous polyethylene film, thereby reducing diffuse reflection of light, making it easy to achieve a desired appearance. Suitable abrasion-resistant polymers and methods of applying them are described in U.S. Patent Application Publication No. 2010 / 0071115, the entire contents of which are incorporated herein by reference. Another method of texturing a film can include applying flocking to at least a portion of the film. A suitable method of applying a flocking material is described in WO 99 / 39038, the entire contents of which are incorporated herein by reference.

[0095] It has also been found that films and articles, such as laminates containing the films, can provide a substantially permanent crease without the need for additional chemicals currently used. This is particularly useful for garments, such as pants, that include a film and at least one textile layer. It has been found that when a laminate containing a film and a textile is placed in a tensioning frame, heated, and then cooled, upon removal from the frame, a crease appears in the portion of the laminate that was secured to the frame. The heating temperature should be 125°C or higher, or 130°C to 190°C. In embodiments where a crease is desired, such as a garment, the crease can be created by folding the article and pressing it with heat. [Example]

[0096] The following examples will explain the embodiments of the present invention, but the technical scope of the present invention is not limited to these examples.

[0097] Test Method

[0098] molecular weight

[0099] Molecular weight measurements were performed according to the procedure described in Mead, DW, Determination of Molecular Weight Distributions of Linear Flexible Polymers from Linear Viscoelastic Material Functions, Journal of Rheology 1994, 38(6): 1797-1827.

[0100] porosity

[0101] Porosity, expressed as percent porosity, was calculated by subtracting the quotient of the average density of the porous polyethylene membrane and the true density of the polymer from 1 and multiplying the result by 100. For this calculation, the true density of polyethylene was taken as 0.94 grams per cubic centimeter. The density of the sample was calculated by dividing the mass / area of ​​the sample by its thickness.

[0102] Water Vapor Transmission Rate Test Protocol

[0103] MVTR is measured in accordance with DIN EN ISO 15496 (2004). As this is a standard test used in the textile industry, reference is made to the detailed description of the MVTR test disclosed in DIN EN ISO 15496 (2004). See also WO 90 / 04175 for a description of the MVTR test.

[0104] The basic principle is summarized as follows: The sample to be tested is inserted into a ring-shaped sample support together with a highly water vapor permeable but waterproof microporous membrane. This support is then immersed in water (deionized water at 23°C) for 15 minutes so that the membrane is in contact with the water. A cup is filled with a saturated aqueous solution of potassium acetate to achieve a relative humidity of 23% at the sample surface and covered with a second, waterproof microporous membrane. The cup containing the potassium acetate solution and the second membrane is weighed and then placed on the sample support so that the second membrane is in contact with the sample. This allows water vapor to migrate from the water side through the sample into the cup containing potassium acetate. After 15 minutes, the cup containing potassium acetate is removed and its weight is measured. To measure the water vapor transmission rate of the test setup without a sample, the same procedure is performed with the first and second membranes, but without the sample. The MVTR of the sample is then determined from the difference between both measurements, taking into account the influence of the two additional microporous membranes.

[0105] The moisture vapor transmission rate (MVTR) of the laminate according to the invention is measured according to EN ISO 15496 (2004) and is expressed in g / m 2 To be considered moisture vapor permeable as used herein, the laminate must have a total moisture vapor permeability of at least 3000 g / m². 2 / 24hr, preferably at least 8000g / m 2 / 24hr, more preferably at least 12000g / m 2 The MVTR value should be 20,000 g / m² / 24 hr. 2 / can reach 24hr.

[0106] Gurley number

[0107] The Gurley airflow test showed a 100cm drop under a 12.4cm water column pressure. 3 6.45cm of air 2The time in seconds required for the sample to pass through is measured. The samples were measured using a Gurley Densometer Model 4110 automatic densometer equipped with a Gurley Model 4320 automatic digital timer. Reported results are the average of multiple measurements.

[0108] Matrix Tensile Strength (MTS)

[0109] To measure MTS, sample membranes were cut in the longitudinal and transverse directions using an ASTM D412F-type dogbone die. Tensile break loads were measured using an INSTRON® 5500R (Illinois Tool Works Inc., Norwood, Massachusetts) tensile tester equipped with flat grips and a 90.72 kg load cell. The grip gauge length was set to 8.26 cm, and a strain rate of 0.847 cm / s or 14.3% / s was used. After placing the sample in the grips, the sample was retracted 1.27 cm to obtain a baseline, and then tensile testing was performed at the aforementioned strain rate. Two samples were tested separately for each condition, and the average of the maximum load (i.e., peak force) measurements was used for MTS calculations. The longitudinal and transverse MTS were calculated using the following equation: MTS = (maximum load / cross-sectional area) x (true density of polymer / density of membrane)

[0110] Thickness measurement

[0111] The thickness of the membrane was measured by placing the membrane between the two plates of a Kafer FZ1000 / 30 thickness snap gauge (Kafer Messuhrenfabrik GmbH, Villingen-Schwenningen, Germany). The average of three measurements was used.

[0112] Mass per unit area (grams / square meter)

[0113] The mass per unit area (mass / area) of the sample was calculated by measuring the mass of a well-defined area of ​​the sample on a scale. The sample was cut to a predetermined area using a die or any precision cutting tool.

[0114] color analysis

[0115] A spectrophotometer, Color i5 (X-Rite Incorporated, Grand Rapids, Michigan), was used to measure the CIE 1931 XYZ color space, and L * a * b * The tristimulus values, designated X, Y, and Z, of the film samples in the CIELAB color space, referred to as the "XYZ" color space, were measured. The aperture size was set to 8 mm. Color measurements were performed using white and black as background colors behind the film. The resulting stimulus values ​​are X, Y, and Z for white, and X, Y, and Z for black, respectively. In the CIELAB color space, the resulting values ​​are L for black. * , a * and b * , and L for white * , a * , b * The calibration tile was used against a white background, and the calibration black trap was used against a black background. Of the XYZ stimulus values, the Y stimulus value is known to represent the luminous transmittance. The opacity Op (%) of the film was calculated using the following formula: Op(%)=(Y 黒色に対して / Y 白色に対して ) x 100

[0116] gloss

[0117] Gloss measurements were performed on the polymer-coated surface at an angle of 85° across the width of the sample using a BYK "micro-TRI-gloss μ" device. Reported data are the average of three individual measurements.

[0118] Heat Resistance Test

[0119] To evaluate the heat resistance of the film, three pieces of film were cut into 150 mm squares. A 100 mm square was printed on the surface of the film with heat-resistant ink. The sample was hung in a tension-free convection oven (ST-120, Espec Corporation, Osaka) and heated at the set temperature for 30 seconds. After heating, the sample was removed from the oven and cooled, and the lengths of the four sides of the square were measured. The initial length L before heating was MD1、 L TD1 (mm) Average length of each side after heating L MD2 , L TD2 (mm), the dimensional change rate D of the sample LMD , D LTD (%), and area change rate D 面積 The dimensional change rate and area change rate were calculated using the following formulas. D LMD (%)=(L MD2 -L MD1 ) / L MD1 ×100 D LTD (%)=(L TD2 -L TD1 ) / L TD1 ×100 D 面積 (%)=((L MD2 ×L TD2 )-(L MD1 ×L TD1 )) / (L MD1 ×L TD1 ) x 100

[0120] Laundry treatment

[0121] Laminate fabric samples cut into 350 mm squares were washed using synthetic laundry detergent (Kao Corporation's "Attack Bio EX") in a commercially available fully automatic washing machine (Panasonic Corporation's "NA-F70PB2"), followed by drying at room temperature. This cycle constituted one cycle. The samples were washed five times using this cycle. The samples were washed for six minutes using 40 liters of tap water and 24 grams of detergent, rinsed twice, and then spun for five minutes.

[0122] Water resistance test

[0123] The water resistance test was carried out using a water resistance tester described in the low water pressure method of JIS L 1092 ("Shopper-type water resistance tester" (WR-1600M, Daiei Scientific Instruments Manufacturing Co., Ltd., Kyoto). After applying a water pressure of 9.8 kPa to the laminated sample from the textile side for 1 minute, the water resistance was judged to be insufficient if water appeared on the fabric surface on the side opposite to the side where the water pressure was applied, and was deemed to be sufficient if no water was observed.

[0124] SEM

[0125] The surface and cross section of the polymer-coated film were observed using an electron microscope at a magnification of 200x for the surface and 2000x for the cross section. The electron microscope used was a "Scanning Electron Microscope S-3000H" available from Hitachi High-Tech Corporation.

[0126] Example 1

[0127] (Polyethylene film)

[0128] A 30-micron-thick polyethylene membrane (available from Gelon LIB Co., Ltd., China) with a weight-average molecular weight of 769,000 g / mol was stretched at a ratio of 1.5:1 in the MD and then at a ratio of 5:1 in the TD. The resulting polyethylene membrane had a mass of 4.1 g / m², a thickness of 13.9 microns, a Gurley number of 32.7 seconds, and a porosity of 69%.

[0129] (hydrophilic polymer)

[0130] Hydrophilic Prepolymer B was prepared according to the teachings of US Pat. No. 6,720,401 (corresponding to Japanese Patent No. 4788020) to provide a prepolymer containing isocyanate groups.

[0131] (Release liner)

[0132] The LDPE release liner was 40 microns "Pearskin finish Natural" supplied by Hayashi Ichiji Co., Ltd. It was 40 microns thick and had a pear skin finish on one side and a smooth surface on the other side.

[0133] (composite film)

[0134] The polyethylene film was printed on a 20 cm cell using a gravure printing method. 3 / m 2 The porous polyethylene film was coated with the above-mentioned Prepolymer B using a printing method (printing speed: 10 m / min, surface coverage: 70%, 100 lines / inch) at a temperature of 25°C. The amount of Prepolymer B applied was 10 grams / m². Immediately after printing Prepolymer B onto the porous polyethylene film, a release liner was placed over the printed surface and sufficient pressure was applied by passing a roller over it. During this process, the smooth surface of the release liner faced the coated surface of the film. As Prepolymer B spread and penetrated into the porous polyethylene film, the composite film changed from a cloudy appearance to a translucent appearance. The resulting product (i.e., composite film) was left at room temperature for 12 hours (temperature: 25°C, relative humidity: 70%) to allow Prepolymer B to cure by reaction with moisture in the air. After curing was complete, the release liner was removed from the composite film to obtain a hydrophilic polyurethane-coated polyethylene film, "Film of Example 1." The mass per unit area, thickness, Gurley number, and moisture permeability were measured. The results are shown in Table 1.

[0135] Example 2

[0136] (Composite Film) The film of Example 2 was prepared using a different gravure printing pattern (cell volume 30 cm 3 / m 2 The film was produced under the same process conditions as in Example 1, except that a coating amount of prepolymer B was 15 grams per square meter by using a prepolymer (70% surface coverage, 100 lines / inch) and the smooth side of a release liner was superimposed on the printed side of the film.

[0137] The test results for the film of Example 2 are shown in Table 1.

[0138] Example 3

[0139] (Polyethylene film)

[0140] A 30-micron-thick polyethylene membrane (available from Gelon LIB Co., Ltd., China) with a weight-average molecular weight of 769,000 g / mol was stretched at a 2.25:1 ratio in the MD and then a 9:1 ratio in the TD. The resulting polyethylene membrane had a mass of 2.1 g / m², a thickness of 10.0 microns, a Gurley number of 8.7 seconds, and a porosity of 78%.

[0141] (composite film)

[0142] The film of Example 3 was obtained by carrying out the film manufacturing process under the same process conditions as in Example 1, except that the above 2.1 g / m² polyethylene film was used as the composite, Prepolymer B was printed on the pear-skin side of the release liner, and the release liner printed with Prepolymer B was laminated to the polyethylene film. The test results of the film of Example 3 are shown in Table 1.

[0143] Example 4

[0144] (silver hydrophilic prepolymer)

[0145] A silver-colored hydrophilic prepolymer (Prepolymer SV) was obtained by mixing 150 g of MCF #1000 carbon black (Mitsubishi Chemical Corporation, Tokyo), 670 g of EMR-DZ510 (Toyo Aluminum Co., Ltd., Osaka), and 9,180 g of Prepolymer B in a kneader mixer. The isocyanate group content of Prepolymer SV was 6.8 wt%, and the viscosity of this prepolymer was 18,000 mPa·sec.

[0146] (composite film)

[0147] The film of Example 4 was prepared by applying prepolymer SV instead of prepolymer B and using a different gravure printing pattern (cell volume 30 cm). 3 / m 2 The film was obtained by carrying out the film manufacturing process under the same process conditions as in Example 1, except that the coating amount of prepolymer SV was 15 grams / square meter by using a 100-line polyester film (70% surface coverage, 100 lines / inch).

[0148] The test results for the film of Example 4 are shown in Table 1.

[0149] Example 5

[0150] (Release liner)

[0151] The release liner used was Asahi release "cube-2M" (Asahi Roll Co., Ltd., Tokyo), a release liner made of polyethylene film-laminated paper. The total thickness of the release liner was 150 microns. This release liner had a unique embossed geometric pattern on the polyethylene film-laminated surface of the release liner.

[0152] (composite film)

[0153] The film of Example 5 was obtained by carrying out the film manufacturing process under the same process conditions as Example 1, except that instead of the release liner described in Example 1, an Asahi release "cube-2M" release liner was applied and laminated to the prepolymer printed surface.

[0154] The test results for the film of Example 5 are shown in Table 1.

[0155] Example 6

[0156] (black hydrophilic prepolymer)

[0157] A black hydrophilic prepolymer (Prepolymer BK) was obtained by mixing 150 g of MCF #1000 carbon black (Mitsubishi Chemical Corporation, Tokyo) and 9,850 g of Prepolymer B in a kneader mixer. The isocyanate group content of Prepolymer BK was 7.0 wt %, and the viscosity was 15,000 mPa·sec.

[0158] (composite film)

[0159] The film of Example 6 was obtained by carrying out the film manufacturing process under the same process conditions as in Example 1, except that prepolymer BK was applied instead of prepolymer B, and the 2.1 g / m² polyethylene film described in Example 3 was used as the composite. The test results of the film of Example 6 are shown in Table 1.

[0160] Example 7

[0161] (hydrophilic prepolymer)

[0162] HYPOL™ JT6005 (The Dow Chemical Company, Midland, Michigan) prepolymer is a TDI-based polyurethane prepolymer with an isocyanate group content of 3.0 wt % and a viscosity of 12,000 mPa·sec.

[0163] (composite film)

[0164] The film of Example 7 was obtained by carrying out the film manufacturing process under the same process conditions as in Example 1, except that HYPOL™ JT6005 was applied instead of prepolymer B.

[0165] The test results for the film of Example 7 are shown in Table 1.

[0166] Comparative Example 8

[0167] (Preparation of Hexamethylenediamine Carbamate (HMDC) Paste)

[0168] A hexamethylenediamine carbamate (HMDC) paste was prepared according to the teachings of US Pat. No. 5,209,969 by the following procedure.

[0169] 100 parts by mass of hexamethylenediamine (HMD) was added to 244 parts by mass of ethylene / propylene oxide diol with a hydroxyl value of 110 at 45°C and atmospheric pressure, and CO2 was bubbled into the resulting mixture to form a paste with a solids content of 35% by mass. The decrease in the content of separated free HMD was monitored by titration until the HMD in the paste was converted to HMD carbamate, and the reaction was stopped immediately when the free HMD disappeared.

[0170] (Mixture of HMDC paste and prepolymer B)

[0171] 91 parts by mass of prepolymer B and 9 parts of HMDC paste were mixed in a kneader mixer to obtain "coating mixture A."

[0172] (Coating and curing process)

[0173] "Coating Mixture A" was heated to 50°C and coated onto one side of the surface of the polyethylene film described in Example 1 using a roll coater at a rate of 10 meters / min. The coating amount was controlled at 10 grams / square meter. The polyethylene film coated with Coating Mixture A was cut into a 30 cm square, the four sides of the square were pinned to fix the shape, and the film was placed in a convection oven adjusted to 180°C for 1 minute to activate the reaction between Prepolymer B and HMD by deblocking CO from the diamine. However, the polyethylene film coated with Coating Mixture A immediately melted in the convection oven, and no coated film was obtained.

[0174] Comparative Example 9

[0175] The polyethylene film coated with coating mixture A described in Comparative Example 8 was cut into a 30 cm square, the four sides of the square were pinned to fix the shape, and the square was placed in a convection oven adjusted to 145°C for 30 seconds to activate the reaction between prepolymer B and HMD by deblocking CO from the diamine. After the heating process, coating mixture A turned into a solid and was kept in a constant temperature and humidity chamber at 25°C and 70% RH for 12 hours to completely cure coating mixture A, thereby obtaining the film of Comparative Example 9.

[0176] The test results for the film of Comparative Example 9 are shown in Table 1.

[0177] Comparative Example 10

[0178] (Expanded polytetrafluoroethylene membrane (ePTFE))

[0179] A commercially available ePTFE membrane (WL Gore & Associates, Newark, Del.) was prepared with a membrane mass of 20 grams per square meter, a thickness of 40 microns, a Gurley number of 6 seconds, and a porosity of 80%.

[0180] (Coating and curing process)

[0181] The "Coating Mixture A" described in Comparative Example 8 was heated to 50°C and coated onto one side of the surface of the ePTFE membrane described above at 10 meters / min using a roll coater. The coating amount was controlled at 10 grams / m². The ePTFE membrane coated with Coating Mixture A was cut into a 30 cm square, the four sides of the square were pinned to fix the shape, and the membrane was placed in a convection oven adjusted to 180°C for 1 minute to activate the reaction between Prepolymer B and HMD by deblocking CO2 from the diamine. After the heating process, Coating Mixture A turned solid and was kept in a constant temperature and humidity chamber at 25°C and 70% RH for 12 hours to completely cure Coating Mixture A, yielding the film of Comparative Example 10.

[0182] The test results for the film of Comparative Example 10 are shown in Table 1.

[0183] Comparative Example 11

[0184] The polyethylene microporous membrane described in Example 1 was tested as the film of Comparative Example 11 without any additional treatment.

[0185] The test results for the film of Comparative Example 11 are shown in Table 1.

[0186] Comparative Example 12

[0187] (Mixture of HMDC paste and prepolymer BK)

[0188] 9 parts by mass of the HMDC paste described in Comparative Example 8 and 91 parts by mass of the prepolymer BK described in Example 6 were mixed in a kneader mixer to obtain a "coating mixture B."

[0189] (Coating and curing process)

[0190] "Coating Mixture B" was heated to 50°C and coated onto one side of the surface of the polyethylene film described in Example 3 using a roll coater at 10 meters / min. The coating amount was controlled at 10 grams / m². The polyethylene film coated with Coating Mixture B was cut into a 30 cm square, the four sides of the square were pinned to fix the shape, and the film was placed in a convection oven adjusted to 145°C for 1 minute to activate the reaction between prepolymer BK and HMD by deblocking CO from the diamine. After the heating process, Coating Mixture B turned solid and was kept in a constant temperature and humidity chamber at 25°C and 70% RH for 12 hours to completely cure Coating Mixture B, obtaining the film of Comparative Example 12.

[0191] The test results for the film of Comparative Example 12 are shown in Table 1.

[0192] Comparative Example 13

[0193] Prepolymer B prepared in Example 1 was coated onto the smooth surface of the release liner described in Example 1 at 25°C using a Mayer bar. The coating amount was 60 g / m 2 After moisture curing for 12 hours in an environment of 25°C and 70% humidity, the film was peeled off from the release liner to form a film consisting only of the hydrophilic polymer, which was designated as the film of Comparative Example 13. The thickness of this film was approximately 70 μm.

[0194] Film-level test results

[0195] As summarized in Table 1, the films obtained from Examples 1 to 7 and Comparative Examples 9 and 12 exhibited excellent lightness, breathability, and moisture permeability. The film of Comparative Example 10 was relatively thicker and heavier than the other examples. The film of Comparative Example 11, which did not have a hydrophilic polymer coating, exhibited the breathability of a porous membrane.

[0196] [Table 1]

[0197] Cross-sectional observation using SEM

[0198] The cross sections of the films obtained from Examples 1 to 7 and Comparative Examples 9, 10, and 12 were observed under a scanning electron microscope. At 2,000x magnification, the hydrophilic polymer filled the pores of the microporous membrane in all films except Comparative Example 10. The hydrophilic polymer on the coating surface, referred to as the cap layer, was void-free in Examples 1 to 7, whereas voids were present in the cap layer in Comparative Examples 9, 10, and 12.

[0199] [Table 2]

[0200] Opacity / Gloss

[0201] The polymer-coated surfaces of the films of Examples 1 and 3 had a slightly glossy appearance and were highly transparent. Compared to Examples 1 and 3, the polymer-coated surface of the film of Example 2 had a matte finish. On the other hand, this film had high transparency, similar to Examples 1 and 3.

[0202] The film of Comparative Example 9 had an overall whitish appearance and was less transparent than the film of Example 1. Furthermore, the surface on the polymer coating side had a matte appearance.

[0203] The film of Comparative Example 10 had an opaque white appearance with a matte surface on the polymer coating side.

[0204] The film of Comparative Example 11 had an opaque white appearance similar to the film of Comparative Example 10. On the other hand, the surface was glossy compared to the other examples.

[0205] Table 2 shows the results of the gloss and opacity measurements.

[0206] In Examples 1, 2, and 3, the appearance was transparent, and the color of the object inside was not significantly impaired even when seen through the film. On the other hand, the color of the object inside the film tended to become cloudy in the film of Comparative Example 9. In the films of Comparative Examples 10 and 11, the high opacity made it difficult to see the color of the object inside the film.

[0207] Visual appearance of the film

[0208] The film of Example 4 exhibited metallic luster and opacity due to the aluminum pigment present on the surface of the polymer coating side, and the opacity of this film was measured to be 75%.

[0209] The film of Example 5 exhibited a unique appearance in which the pattern of the release liner was transferred to the surface of the cap layer on the polymer coating side, resulting in a regular cubic pattern. A micrograph of the cubic pattern on the film is shown in Figure 5.

[0210] Example 6 exhibited a coal-like black color due to the hydrophilic polymer coating mixed with carbon pigment. On the other hand, Comparative Example 12, despite using the same carbon-containing polymer as Example 6, exhibited a dark gray color on the hydrophilic polymer coating side. The difference in film appearance between Example 6 and Comparative Example 12 is thought to be due to the voids in the cap layer of the film of Comparative Example 12 diffusing and reflecting light, adding to the dark gray color.

[0211] Tensile test results

[0212] The films obtained in Examples 1, 3, and Comparative Example 13 were subjected to tensile tests based on the aforementioned ASTM D412. As a result, the average maximum load values ​​of the film of Example 1 were 0.98 kgf in MD and 0.63 kgf in TD, respectively. The average maximum load values ​​of the film of Example 3 were 0.60 kgf in MD and 0.50 kgf in TD, respectively. On the other hand, the average maximum load value of the film of Comparative Example 13 was only 0.09 kgf in both directions.

[0213] Heat resistance test results

[0214] The films obtained in Examples 1 and 3 and Comparative Example 11 were subjected to heat treatment at set temperatures of 150°C and 170°C for 30 seconds in the heat resistance test described above, and the area change rate D after heat treatment was 面積 The area change rate (%) was calculated. Table 3 summarizes the results of the area change rate measurement. Examples 1 and 3 did not show a large change in area due to the heat treatment, but Comparative Example 11 showed a large change in dimension, which indicates that the polyethylene microporous membrane alone cannot provide heat resistance.

[0215] [Table 3]

[0216] Laminate example

[0217] Nylon woven fabric for outer textiles

[0218] An undyed plain weave nylon fabric was prepared from 33 decitex light-colored filament yarn manufactured by Asahi Kasei Corp. The textile had a translucent appearance.

[0219] Laminated and water-repellent finish

[0220] Example 1A

[0221] A urethane-based moisture-curing hot-melt adhesive (DIC Corporation's "Tyforce NH-320") was used to bond the outer textile to the film obtained in Example 1. The temperature of the adhesive was set to 110°C. The molten adhesive was applied in a dot pattern to the surface of the film opposite the hydrophilic polymer coating using a gravure roll with a 40% coverage, resulting in a transfer amount of 5 grams / m² of adhesive. The outer textile and the film of Example 1 were then pressed together with the roll and left in a constant temperature and humidity chamber at 40°C and 80% RH for 24 hours to cure the hot-melt adhesive, resulting in a two-layer laminate.

[0222] Next, a fluorine-based water-repellent treatment was applied to the surface of the outer fabric of this two-layer laminate using a kiss coater in an amount exceeding the saturation amount, and the excess dispersion was removed by pressing with a mangle roll.

[0223] The amount of the dispersion absorbed by the outer fabric was approximately 20 g / m2. The laminated product was then dried in a hot air circulating oven at 140°C for 30 seconds to obtain a two-layered laminated product that had been treated with a water repellent treatment.

[0224] Laminate 10A

[0225] The film of Comparative Example 10 was laminated in the same manner as Example 1A.

[0226] Laminate 11A

[0227] The film of Comparative Example 11 was laminated in the same manner as in Example 1A, except that the heating temperature in the water-repellent treatment step was 90° C. for 60 seconds.

[0228] Appearance of the laminate

[0229] Laminate Example 1A exhibited a translucent appearance, while Laminate Examples 10A and 11A exhibited an opaque white appearance resulting from the color of the laminate film.

[0230] Laminate test results

[0231] Home washing and water resistance test results

[0232] After five home washes using detergent, the laminate samples obtained in the above examples were hung to dry under ambient conditions. When water pressure was applied to the textile side of the laminate to measure water pressure resistance, both Example 1A and Example 11A maintained their initial water pressure resistance of 9.8 kPa. After five home washes, no water leakage was observed in Example 1A, but water leakage up to 9.8 kPa was observed in Example 11A. Furthermore, after five home washes, the appearance of Laminate Example 1A maintained a translucent appearance even in the wet areas after the water resistance test, with no significant contrast between the dry and wet areas. After five home washes, the appearance of Example 11A became translucent in the wet areas after the water resistance test, creating a significant contrast between the dry and wet areas. This change in appearance is believed to be due to the membrane layer within the laminate changing from an opaque white to a translucent color due to wetting of the porous layer by water. During the washing of the laminate samples, detergent contaminated the porous polyethylene membrane, causing it to change from hydrophobic to hydrophilic. On the other hand, Example 1A did not have a porous layer in the film, so water did not penetrate into the film layer during the water resistance test.

[0233] The laminate of Example 10A was able to maintain a water pressure resistance of 9.8 kPa before and after five home washing and drying cycles. However, in the sample after five home washings, the appearance of the laminate in the wetted areas changed from opaque white to translucent upon application of water pressure, similar to Example 11A. Even if Example 10A was able to maintain the waterproof properties of the laminate after home washing, this change in appearance could be problematic, detracting from its aesthetic appearance, for example, by creating areas that appear translucent and therefore have an overall uneven and undesirable appearance when used as clothing.

[0234] While several embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, not limiting, and that many modifications may be apparent to those skilled in the art. For example, all dimensions discussed herein are provided by way of example only and are intended to be illustrative, not limiting.

Claims

1. A film, A) a microporous polyethylene membrane, the microporous polyethylene membrane comprises polyethylene; the polyethylene having a weight average molecular weight greater than 500,000 grams / mole; the microporous polyethylene membrane has a porosity of at least 40% by volume; a microporous polyethylene membrane, the microporous polyethylene membrane having a Gurley number of less than 200 seconds; B) a hydrophilic polymer, a portion of the hydrophilic polymer is present within at least some of the pores of the microporous polyethylene membrane, and at least a portion of the hydrophilic polymer forms a cap layer present on at least one surface of the microporous polyethylene membrane; The cap layer is substantially void-free and comprises a hydrophilic polymer. Including, the film.

2. 10. The film of claim 1, wherein the hydrophilic polymer within the microporous polyethylene membrane fills substantially all of the pores of the microporous polyethylene membrane.

3. 3. The film of claim 1 or 2, wherein the film further comprises a release layer, the release layer being adjacent to the cap layer.

4. The film of claim 1 , wherein the cap layer has a controlled surface morphology.

5. 5. The film of claim 4, wherein the controlled surface morphology comprises a transfer printed surface from a release layer disposed on the cap layer.

6. 10. The film of claim 1 having an opacity of 10 to 85.

7. The film according to claim 1, having a heat resistance of 190°C or less.

8. The film according to claim 1, having a tensile strength of 0.45 kgf or more in the machine direction.

9. The film according to claim 1, having a tensile strength of 0.36 kgf or more in the TD direction.

10. The film of claim 1 , wherein the hydrophilic polymer comprises a polyurethane, a polyamide, a polyester, an epoxy resin, a silicone resin, an ionomer, or a copolymer thereof, or a combination thereof.

11. 10. The film of claim 1 having a Gurley number of 1000 seconds or greater.

12. 10. The film of claim 1 having a surface gloss of 3.0 gloss units or greater.

13. 2500g / m ２ 10. The film of claim 1, having a water vapor transmission rate of 1000 ppm / day or more.

14. An article comprising the film of any one of claims 1 to 13.

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