Non-permeable film containing polymer blend and method for producing the same

Abstract

Non-breathable films comprising specific polymer blends and methods of making such films are provided. The films comprise an anhydride and / or carboxylic acid functionalized ethylene / alpha-olefin interpolymer, a linear low density polyethylene, and an inorganic filler. The method of making the film includes extruding the anhydride and / or carboxylic acid functionalized ethylene / alpha-olefin interpolymer, the linear low density polyethylene, and the inorganic filler to form a film, and stretching the film. Films according to embodiments disclosed herein can exhibit low WVTR values ​​and improved modulus while also incorporating significant amounts of inorganic fillers at low gauge.

Description

[Technical Field]

[0001] Embodiments of this disclosure generally relate to films, and more specifically to non-permeable films comprising a particular polymer blend. [Background technology]

[0002] Introduction Non-permeable films are used in a wide variety of applications, including infant diapers, adult incontinence products, surgical gowns, and other hygiene and medical applications. For example, diaper backsheet films can be classified as permeable or non-permeable films depending on the film's microporous morphology or water vapor transmission rate ("WVTR"). Typically, permeable films are made by incorporating large amounts (more than 30% by weight) of inorganic fillers (e.g., CaCO3) into the polymer to form pores, provide permeability, and reduce costs. Non-permeable films may also contain fillers such as CaCO3 to reduce costs, but do not contain large amounts (more than 30% by weight) of fillers such as CaCO3, as these fillers can form pores, provide permeability, and impair mechanical properties. Instead, non-permeable films are typically formed from blends of high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and low-density polyethylene (LDPE), collectively, with HDPE providing rigidity, LLDPE providing toughness, and LDPE providing processability.

[0003] Therefore, there is still a need for cost-effective, non-permeable film formulations that contain inorganic fillers and exhibit improvements or maintenance of mechanical properties such as elastic modulus and tensile properties. [Overview of the Initiative]

[0004] Embodiments of this disclosure include a larger amount (40-70% by weight) of inorganic filler and have a low WVTR (1,100 g / m²). 2*The aforementioned need is met by providing a film that can have a WVTR of less than 1 day. The film of the present invention comprises anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer and linear low-density polyethylene. Although not bound by any theory, the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, when combined with linear low-density polyethylene and inorganic fillers, prevents cavitation, thereby reducing or eliminating permeability while maintaining or improving mechanical properties. Films according to the embodiments disclosed herein can exhibit low WVTR values ​​and improved modulus of elasticity, while also being able to incorporate a considerable amount of inorganic fillers at low gauge.

[0005] A film is disclosed herein. The film comprises (a) 1 to 15% by weight of an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point less than 100°C, and (b) 20 to 59% by weight of 0.900 g / cm³ 3 ~0.940g / cm 3 (c) a linear low-density polyethylene having a density and a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min, and (c) 40 to 70% by weight of an inorganic filler selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, where the weight percentage is based on the total weight of the film, and the film has a density of 1,100 g / m². 2* It has a water vapor transmission rate (WVTR) of less than 1 day and an elongation ratio of at least 2:1.

[0006] A method for producing the film is also disclosed herein. The method involves 1 to 15% by weight of an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, and 20 to 59% by weight of 0.900 g / cm³ 3 ~0.940g / cm 3The present invention provides a linear low-density polyethylene having a density and a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min, and an inorganic filler of 40 to 70% by weight selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, wherein the weight percentage is based on the total weight of the film, and comprises extruding the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, the linear low-density polyethylene, and the inorganic filler to form the film, and stretching the film to a stretch ratio of at least 2:1.

[0007] These and other embodiments are described in more detail in “Modes for Carrying Out the Invention.” [Modes for carrying out the invention]

[0008] The embodiments of the disclosed film are described in more detail below. The film may have a wide variety of applications, including, for example, infant diapers, adult incontinence products, surgical gowns, and other hygiene and medical applications. However, this disclosure may be embodied in different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure may be thorough and complete and so as to convey the scope of the subject matter to those skilled in the art.

[0009] As used herein, the term "polymer" means a polymeric compound prepared by polymerizing monomers, whether of the same or different types. Thus, the general term "polymer" encompasses the term "homopolymer" (used to refer to a polymer prepared from only one type of monomer) and the terms "copolymer" or "interpolymer". Trace amounts of impurities (e.g., catalyst residues) can be incorporated in and / or into the polymer. The polymer can be a polymer mixture including a single polymer, a polymer blend, or a mixture of polymers formed in situ during polymerization.

[0010] As used herein, the term "polyethylene" means a polymer containing a majority (> 50 mol%) of units derived from ethylene monomers.

[0011] As used herein, the term "interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers.

[0012] As used herein, the term "ethylene / alpha-olefin interpolymer" refers to an interpolymer containing a majority of ethylene monomers (based on the weight of the interpolymer) and at least one alpha-olefin monomer in polymeric form.

[0013] As used herein, the term "anhydride and / or carboxylic acid functionalized ethylene / alpha-olefin interpolymer" refers to an ethylene / alpha-olefin interpolymer containing at least one anhydride group and / or at least one acid group (e.g., -COOH formed by hydrolysis of an anhydride) linked by a covalent bond. Examples of anhydride and / or carboxylic acid functionalized ethylene / alpha-olefin interpolymers are maleic anhydride functionalized ethylene / alpha-olefin interpolymers.

[0014] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless otherwise stated. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any subsequent description, except those not essential to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or listed.

[0015] The films disclosed herein comprise an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, linear low-density polyethylene, and an inorganic filler.

[0016] In embodiments, the film comprises 1 to 15 weight percent ("wt%) of anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, where wt% is based on the total weight of the film. All individual values ​​and partial ranges of 1 to 15 wt% are disclosed and included herein. For example, the film may comprise 1 to 15 wt%, 5 to 15 wt%, or 8 to 12 wt% of anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, where wt% is based on the total weight of the film.

[0017] In embodiments, the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer has a melting point below 100°C, which can be measured according to ISO 3146. All individual values ​​and partial ranges below 100°C are disclosed and included herein. For example, the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer may have a melting point below 100°C, below 95°C, below 90°C, below 85°C, below 80°C, below 75°C, below 70°C, or below 65°C; or it may have a melting point in the range of 55°C to 95°C, 55°C to 85°C, 55°C to 75°C, 55°C to 65°C, 60°C to 90°C, 60°C to 80°C, or 60°C to 70°C, which can be measured according to ISO 3146.

[0018] In the embodiment, the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer is 0.910 grams / cubic centimeter (g / cm³). 3 They have a density of less than 0.910 g / cc. All individual values ​​and subranges less than 0.910 g / cc are disclosed and included herein. For example, anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymers may have a density of less than 0.910 g / cc, less than 0.900 g / cc, less than 0.890 g / cc, less than 0.880 g / cc, or less than 0.870 g / cc; or they may have a density in the range of 0.860 to 0.910 g / cc, 0.860 to 0.900 g / cc, 0.860 to 0.890 g / cc, 0.860 to 0.880 g / cc, or 0.865 to 0.875 g / cc.

[0019] In embodiments, the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer has an anhydride or acid content of 0.1 to 2.0% by weight, where the weight percentage of the anhydride or acid content is based on the total weight of the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer. All individual values ​​and partial ranges of 0.1 to 2.0% by weight are disclosed and included herein. For example, the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer may have an anhydride or acid content of 0.1 to 2.0% by weight, 0.3 to 2.0% by weight, 0.5 to 2.0% by weight, 0.7 to 2.0% by weight, or 1.0 to 2.0% by weight, where the weight percentage of the anhydride or acid content is based on the total weight of the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer.

[0020] In the embodiment, an anhydride and / or carboxylic acid functional groups are grafted onto an ethylene / alpha-olefin interpolymer.

[0021] In the embodiment, the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer is maleic anhydride-functionalized ethylene / alpha-olefin interpolymer. For example, in the embodiment, the film contains 1 to 15% by weight of maleic anhydride-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, where the weight percentage is based on the total weight of the film.

[0022] Examples of anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymers suitable for use in embodiments of the present invention include, for example, specific anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymers of the trademark name BYNEL®, including BYNEL® 46E1060, which is commercially available from The Dow Chemical Company (Midland, MI).

[0023] The film disclosed in this specification contains linear low-density polyethylene. In an embodiment, the film contains 20 to 59% by weight of linear low-density polyethylene, and the % by weight is based on the total weight of the film. All individual values and subranges of 20 to 59% by weight are disclosed and incorporated herein. For example, the film may contain 20 to 59% by weight, 20 to 50% by weight, 20 to 45% by weight, 30 to 59% by weight, 30 to 50% by weight, 30 to 45% by weight, 35 to 59% by weight, 35 to 50% by weight, or 35 to 45% by weight of linear low-density polyethylene, and the % by weight is based on the total weight of the film.

[0024] In an embodiment, the linear low-density polyethylene has a density of 0.900 g / cm 3 to 0.940 g / cm 3 . All individual values and subranges of 0.900 g / cm 3 to 0.940 g / cm 3 are disclosed and incorporated herein. For example, the linear low-density polyethylene may have a density of 0.900 g / cm 3 to 0.940 g / cm 3 , 0.905 g / cm 3 to 0.935 g / cm 3 , 0.910 g / cm 3 to 0.930 g / cm 3 , or 0.915 g / cm 3 to 0.925 g / cm 3 , and the density can be measured in accordance with ASTM D792.

[0025] In embodiments, linear low-density polyethylene has a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min. All individual values ​​and subranges of 0.1 g / 10 min to 10.0 g / 10 min are disclosed and incorporated herein. For example, linear low-density polyethylene may have a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min, 0.5 g / 10 min to 10.0 g / 10 min, 1.0 g / 10 min to 10.0 g / 10 min, 0.1 g / 10 min to 5.0 g / 10 min, 0.5 g / 10 min to 5.0 g / 10 min, or 1.0 g / 10 min to 5.0 g / 10 min, and the melt index (I2) can be measured according to ASTM D1238.

[0026] Examples of linear low-density polyethylene suitable for use in embodiments of the present invention include, for example, certain linear low-density polyethylenes of the trademark name DOWLEX®, including DOWLEX® 2111 GC polyethylene resin, which is commercially available from The Dow Chemical Company (Midland, MI).

[0027] The films disclosed herein also include inorganic fillers. The inorganic fillers are selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof. In embodiments, the film contains 40–70% by weight of an organic filler selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof. All individual values ​​and partial ranges of 40–70% by weight are disclosed and incorporated herein. For example, the film may contain 40-70% by weight, 40-60% by weight, 40-55% by weight, 45-70% by weight, 45-60% by weight, or 45-55% by weight of an inorganic filler, where the weight percentage is based on the total weight of the film.

[0028] In embodiments, the inorganic filler has a median particle size (D50) of less than 5 microns (also known as micrometers (μm)). All individual values ​​and subranges less than 5 microns are disclosed and included herein. For example, the inorganic filler may have a median particle size (D50) of less than 4 microns, less than 3 microns, less than 2 microns, or less than 1 micron, or may be in the range of 0.1 to 4 microns, 0.1 to 3 microns, 0.1 to 2 microns, or 0.1 to 1 micron.

[0029] In this embodiment, the inorganic filler of the film is calcium carbonate.

[0030] The films disclosed herein may incorporate additives such as antioxidants (e.g., hindered phenols such as IRGANOX® 1010 or IRGANOX® 1076 supplied by BASF), phosphites (e.g., IRGAFOS® 168, also supplied by BASF), processing aids, UV light stabilizers, heat stabilizers, pigments, colorants, antistatic additives, flame retardants, slip agents, antiblocking additives, biocides, antimicrobial agents, and clarifying / nucleating agents (e.g., HYPERFORM® HPN-20E, MILLAD® 3988, MILLAD® NX 8000, available from Milliken Chemical). Additives may be included in the films at levels typically used in the art to achieve their desired purposes. In some examples, the product contains one or more additives in amounts ranging from 0 to 10% by weight based on the total weight of the film, 0 to 5% by weight based on the total weight of the film, 0.001 to 5% by weight based on the total weight of the film, 0.001 to 3% by weight based on the total weight of the film, 0.05 to 3% by weight based on the total weight of the film, or 0.05 to 2% by weight based on the total weight of the film.

[0031] The films disclosed herein are non-air permeable films. As used herein, the term “non-air permeable” means 1,100 g / m² 2*This refers to a film having a water vapor transmission rate (WVTR) of less than 1,100 g / m². The film of the present invention has an even lower WVTR value (1,100 g / m²). 2* While maintaining a WVTR of less than 1 day, it is possible to increase the amount of inorganic filler (40-70% by weight of inorganic filler). This result is unexpected, as higher levels of filler typically result in greater cavitation and higher WVTR values ​​in the film. Although not bound by any theory, anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymers, in combination with linear low-density polyethylene and inorganic fillers, prevent cavitation, thereby reducing WVTR while maintaining or improving mechanical properties. It is thought that anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymers can interact with inorganic fillers and linear low-density polyethylene to prevent cavitation, reduce pore formation and WVTR.

[0032] The film disclosed herein has a density of 1,100 g / m². 2* It has a water vapor transmission rate (WVTR) of less than 1,100 g / m². 2* All individual values ​​and sub-ranges less than a day are disclosed and incorporated herein. For example, the film is 1,100 g / m². 2* Less than 1,000g / m² 2* Less than 900g / m² 2* Less than 1 day, 800g / m² 2* Less than 7 days, 700g / m² 2* Less than 600g / m² 2* Less than one day, or 500g / m² 2* It may have a WVTR of less than 1 day; or the film may have a weight of 400-1,100 g / m². 2* day, 400~1,000g / m 2* day, 400~800g / m 2* day, 400~600g / m 2* day, 500~1,100g / m 2* Daily, or 500-800g / m² 2* It may have a WVTR in the range of days, and WVTR can be measured according to ASTM E398.

[0033] The basis weight of the film is not particularly limited, but in some embodiments it may be 5 to 50 gsm. The basis weight of the film may depend on a number of factors, including the desired properties of the film, the end use of the film, the equipment available to manufacture the film, the cost acceptable by the application, and other factors. All individual values ​​and partial ranges of 5 to 50 gsm are included and disclosed herein. For example, in some embodiments, the film may have a basis weight of 5 to 50 gsm, 5 to 40 gsm, 5 to 30 gsm, 5 to 20 gsm, 10 to 50 gsm, 10 to 40 gsm, 10 to 30 gsm, or 10 to 20 gsm.

[0034] The films disclosed herein have a stretch ratio of at least 2:1. Stretching the film can increase the WVTR, but stretching can also improve or enhance the film's mechanical properties, such as its modulus of elasticity and tensile properties, and can enable down-gauging of the film. The films of the present invention according to the embodiments disclosed herein have a low WVTR (1,100 g / m²). 2* The inorganic filler can be made to a higher level while maintaining (less than 1 day) and while maintaining or improving mechanical properties such as elastic modulus or tensile properties. In the embodiment, the film has a stretch ratio of at least 2:1, at least 3:1, at least 4:1, or at least 5:1, or a stretch ratio in the range of 2:1 to 6:1, or 3:1 to 6:1.

[0035] 1,100g / m 2* In addition to having a WVTR of less than 1 day and a stretch ratio of at least 2:1, the films according to the embodiments disclosed herein may have a force at 5% strain in the machine direction of more than 2,000 N / 15 mm (film width) (or more than 2,500 N / 15 mm (film width), or more than 3,000 N / 15 mm (film width), or more than 3,500 N / 15 mm (film width), or more than 4,000 N / 15 mm (film width)), and the force at 5% strain in the machine direction can be measured according to the test method described below.

[0036] The films according to the embodiments disclosed herein can be defined with respect to the force at 5% strain in the mechanical direction (MD), the stretch ratio, the weight percentage of the inorganic filler, and the WVTR. For example, the film can be characterized using the following formula:

[0037]

number

[0038] In this embodiment, the film has an X of 0.0060 or higher, or 0.0080 or higher, or 0.0100 or higher. NBB It has X NBB It is defined as shown in the formula above.

[0039] The films according to the embodiments disclosed herein are also intended to include additional layers, either co-extruded or as laminates. These layers may be selected to provide additional functionality, for example, to give the layer exceptional strength, adhesion to another substrate such as a nonwoven fabric, and / or aesthetic properties such as feel or appearance.

[0040] Some embodiments of the present invention relate to laminates comprising one or more films of the present invention. For example, the films of the present invention can be used in film / nonwoven laminates. Typical nonwovens used in such laminates may be spunlaid webs, airlaid webs, card webs, or composites thereof. Typical nonwoven composites for use in laminates with the films of the present invention include spunbond with three beams (e.g., S / S / S), spunbond / meltblown / spunbond composites (e.g., S / M / S), etc. Common methods for bonding the films to the nonwovens include, for example, bonding hot melt adhesive lamination, ultrasonic bonding, and thermal bonding through a calender or nip roll. In embodiments, the laminate comprising the films of the present invention is in adhesive contact with the nonwoven or a second film.

[0041] The present invention also relates to articles comprising at least one of the films of the present invention disclosed herein. Articles comprising the films of the present invention can be used as a liquid-impermeable layer in disposable sanitary and medical products. Examples of articles comprising such films include diapers, training pants, feminine hygiene products, adult incontinence products, medical drapes, medical gowns, surgical gowns, and the like. The films can be incorporated into such articles using techniques known to those skilled in the art based on the teachings herein.

[0042] The films described herein may be produced by a number of processes. Exemplary processes may include blowing or casting the film, and the film may be produced by blowing, casting, or extrusion coating processes. The film may be stretched by mechanical stretching, transverse stretching, ring rolling stretching, cold stretching, or a combination thereof.

[0043] A method for producing the film of the present invention is also disclosed herein. In embodiments, the method for producing the film comprises 1 to 15% by weight of an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, and 20 to 59% by weight of 0.900 g / cm³ 3 ~0.940g / cm 3 The present invention provides a linear low-density polyethylene having a density and a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min, and an inorganic filler of 40 to 70% by weight selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, wherein the weight percentage is based on the total weight of the film, and comprises extruding the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, the linear low-density polyethylene, and the inorganic filler to form the film, and stretching the film to a stretch ratio of at least 2:1.

[0044] In the embodiment, the method for producing the film includes the step of compounding an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, linear low-density polyethylene, and an inorganic filler before extruding the material into a film. For example, in the embodiment, the method for producing the film includes 1 to 15% by weight of an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, and 20 to 59% by weight of 0.900 g / cm³ 3 ~0.940g / cm 3 The present invention provides linear low-density polyethylene having a density and a melt index (I2) of 0.1 g / 10 min to 10.0 g / 10 min, and an inorganic filler selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, wherein the weight percentage is based on the total weight of the film, and comprises forming a masterbatch formulation by compounding the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, the linear low-density polyethylene, and the inorganic filler, extruding the masterbatch formulation to form a film, and stretching the film to a stretch ratio of at least 2:1.

[0045] Test method density Density was measured according to ASTM D792, in grams / cm³. 3 (g / cc or g / cm 3 It is represented as ).

[0046] Melt Index (I2) The melt index (I2) is measured according to ASTM D-1238 at 190°C with 2.16 kg. The value is reported as g / 10 min, corresponding to the grams eluted per 10 minutes.

[0047] melting point The melting point is measured according to ISO 3146.

[0048] Water vapor transmission rate (WVTR) Water vapor transmission rate (WVTR) is measured according to ASTM E398.

[0049] Force or absolute tensile strength at 5% strain in MD The force at 5% strain in the mechanical direction (also called absolute tensile force) is measured according to ISO 527-3. The stress value at 5% elongation is reported. The sample width is 15 mm and its length is 100 mm, and the reported value is N / 15 mm (film width). [Examples]

[0050] The following embodiments illustrate the features of the present disclosure, but are not intended to limit the scope of the present disclosure.

[0051] Materials used The films of the embodiments discussed below include the following materials.

[0052] DOWLEX(TM) 2107GC, 0.917g / cm 3 An ethylene-octene copolymer with a density of 2.3 g / 10 min and a melt index (I2), commercially available from The Dow Chemical Company (Midland, MI).

[0053] DOWLEX(TM) 2111GC, 0.920g / cm 3 Linear low-density polyethylene, commercially available from The Dow Chemical Company (Midland, MI), has a density of 3.7 g / 10 min and a melt index (I2).

[0054] BYNEL (trademark) 46E1060, melting point 62.8℃, 0.87 g / cm³ 3A maleic anhydride-functionalized ethylene / alpha-olefin interpolymer, commercially available from The Dow Chemical Company (Midland, MI), having a density of 3 g / 10 min, a melt index (I2), and a maleic anhydride content of 1.0-2.0% by weight.

[0055] ELVALOY (trademark) AC 1820, melting point 92°C, 0.942 g / cm³ 3 An ethylene / methyl acrylate copolymer having a density of 8 g / 10 min, a melt index (I2), and an acrylate content of 20% by weight, commercially available from The Dow Chemical Company (Midland, MI).

[0056] INFUSE(TM)9507, 0.866g / cm 3 An olefin block copolymer having a density and a melt index (I2) of 5.0 g / 10 min, commercially available from The Dow Chemical Company (Midland, MI, USA).

[0057] Calcium carbonate (CaCO3) commercially available from OmyaFilm 753 and Omya AG.

[0058] A film having a final basis weight of 15 gsm is formed according to the following formulation and procedure. The film formulations are described in Table 1 below and are referred to as Comparative Examples 1 to 5 and Example 1 of the present invention.

[0059] [Table 1]

[0060] To form the film, the materials from Comparative Examples 2-5 and Example 1 of the present invention were extruded on a Buss Kneader compounding line to form masterbatch formulations. Comparative Example 1 is a single polymer formulation, so no masterbatch formulation was formed. The formulations were then processed on a Collin Cast extrusion line to form a single-layer film. The film had a final film basis weight of 15 gsm. Table 2 below provides the film processing parameters.

[0061] [Table 2]

[0062] A set of films is prepared from the formulations of each example having different stretch ratios. Comparative Examples 1A, 2A, and Example 1A of the present invention are films with a stretch ratio of "0" (i.e., not stretched at all). Comparative Examples 2B, 3B, 4B, and Example 1B of the present invention are stretched in the machine direction to the minimum stretch ratio (MSR) inherent to each film. As is known to those skilled in the art, the films have an MSR where the film is fully stretched across its entire width and do not have tiger stripes. The MSR of Comparative Example 2B is 3.7:1, the MSR of Comparative Example 3B is 3.9:1, the MSR of Comparative Example 4B is 3.7:1, and the MSR of Example 1B of the present invention is 4.2:1. Comparative Examples 2C, 3C, 4C, and Example 1C of the present invention are stretched in the machine direction to a stretch ratio of 5.5:1.

[0063] Stretching in the machine direction is performed according to the machine direction orientation processing parameters shown in Table 3 below.

[0064] [Table 3]

[0065] The WVTR of the film in each example was measured. Table 4 below provides the results.

[0066] [Table 4]

[0067] Examples 1B and 1C of the present invention show surprising and unexpected results, with lower WVTR values ​​compared to corresponding comparative examples that are stretched at the same or similar stretch ratio and have the same amount of calcium carbonate. Although not bound by any theory, the maleic anhydride-functionalized ethylene / alpha-olefin interpolymer of Example 1 of the present invention can interact with fillers and polymer matrices to reduce pore formation, WVTR, and permeability.

[0068] The force at 5% strain in the MD was also measured. Table 5 below shows the results.

[0069] [Table 5]

[0070] As shown in Table 5, Examples 1B and 1C of the present invention exhibit relatively high values ​​for force at 5% strain in MD compared to comparative examples having the same or similar stretch ratio and the same amount of calcium carbonate. Therefore, the examples of the present invention exhibit lower WVTR and improved modulus or force at 5% strain in MD compared to the corresponding comparative examples. An improvement in force at 5% strain in MD can increase hydrostatic resistance, which is important, for example, to resist the pressure of liquids that may be trapped in an article during the packaging process and when a person wears an article such as a diaper. The films of the present invention exhibit low WVTR values ​​and improved modulus, while also allowing for the incorporation of a considerable amount of inorganic filler at low gauge.

[0071] Parameter X NBB The present invention and the advantageous results of Example 1 of the present invention can be demonstrated using X. NBB This corresponds to the following formula:

[0072]

number

[0073] X in comparative examples and examples of the present invention NBB The result is calculated and provided in Table 6 below.

[0074] [Table 6]

[0075] All documents cited herein, including any cross-referenced or related patents or applications, and any patent applications or patents to which this application claims priority or benefit, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. No reference to any document constitutes prior art relating to any invention disclosed or claimed herein, nor does it teach, suggest or disclose such invention, either alone or in any combination with any other reference. Furthermore, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition assigned to that term in this document shall prevail.

[0076] While specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to encompass all such changes and modifications that fall within the scope of the invention.

Claims

1. It is film, (a) 1 to 15% by weight of an anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, (b) 20–59% by weight, 0.900 g / cm³ ３ ~0.940g / cm ３ The density and melt index (I) of 0.1 g / 10 min to 10.0 g / 10 min ２ Linear low-density polyethylene having ) (c) 40 to 70% by weight of an inorganic filler selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, Includes, The weight percentage is based on the total weight of the film. 1,100 g / m ２＊ Having a water vapor transmission rate (WVTR) of less than 1 day and an elongation ratio of at least 2:1, A film in which the stretch ratio is the minimum stretch ratio (MSR) in the mechanical direction.

2. The film according to claim 1, wherein the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer has an anhydride or acid content of 0.1 to 2.0% by weight, and the weight percentage of the anhydride or acid content is based on the total weight of the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer.

3. The film according to claim 1 or 2, wherein the anhydride and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer is maleic anhydride-functionalized ethylene / alpha-olefin interpolymer.

4. The film according to any one of claims 1 to 3, wherein the inorganic filler is calcium carbonate.

5. The film according to any one of claims 1 to 4, wherein the anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer has a melting point of less than 65°C.

6. The film according to any one of claims 1 to 5, wherein the film has a basis weight of 5 to 50 grams / square meter (gsm).

7. The film according to any one of claims 1 to 6, wherein the film has a force of 2,000 N / 15 mm (film width) or more at a 5% strain in the mechanical direction. [Request Item 8] [Number 1] X is defined as ＮＢＢ The film according to any one of claims 1 to 7, wherein the coefficient is 0.0060 or greater.

9. A laminate comprising a film according to any one of claims 1 to 8, which is in adhesive contact with a nonwoven fabric or a second film.

10. A method for manufacturing a film, 1 to 15% by weight of anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer having a melting point of less than 100°C, and 20 to 59% by weight of 0.900 g / cm³ ３ ~0.940g / cm ３ The density and melt index (I) of 0.1 g / 10 min to 10.0 g / 10 min ２ The present invention provides a linear low-density polyethylene having ) and 40 to 70% by weight of an inorganic filler selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum sulfate, magnesium oxide, calcium oxide, alumina, mica, talc, silica, clay, glass spheres, titanium dioxide, aluminum hydroxide, zeolite, and combinations thereof, wherein the weight percentage is based on the total weight of the film. The anhydrous and / or carboxylic acid-functionalized ethylene / alpha-olefin interpolymer, the linear low-density polyethylene, and the inorganic filler are extruded to form the film. The film is stretched to a stretch ratio of at least 2:1, Includes, The aforementioned stretch ratio is the minimum stretch ratio (MSR) in the machine direction. A method wherein the film has a water vapor transmission rate (WVTR) of less than 1,100 g / m² / day.

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