MXPA99001102A - Breathable movie laminates / nwf having high wvtr, prepared from precursor films of poliolefina / filled in state fund - Google Patents

Abstract

Films, made of polyethylene and fillers, and articles made from them with WVTR higher than previously available films based on conventional ziegler-natta polyethylenes. Polyethylenes are produced in a production process catalyzed by metallocene. The films can be made by means of a forged film process, and can be made with a widely variable filling content, generally polyethylene to fill ratios of 30/70 to 70/30. The polyethylenes based on metallocene, when combined with filler. They also allow the extrusion of thinner films that lead to lighter weight and softer films. The polyethylenes m used to make such films typically have an amplitude index of compositional distribution over 50% and a Mw / Mn ratio of less than A 3, and a Mz / Mw ratio of less than 2. The films can be advantageously used in composite structures with fabrics (whether woven or non-woven) to manufacture items such as wraps for domestic use

Description

BREATHABLE MOVIE LAMINATES / NWF HIGH WVTR, PREPARED FROM PRECURSOR FILMS OF POLYOLEFINE / FILLED IN THE FUNDIDO STATE Technical Field This invention relates generally to polyolefin films having greatly increased WVTR and methods of making them. More specifically, this invention is directed to filled polyethylene films having increased WVTR at a given filler loading and a given set of process conditions. BACKGROUND It is known to prepare films having good WVTR from highly filled polymers, usually polyolefins. In the past, a combination of a polyolefin, usually a polyethylene, with a filler, usually CaC03, but very useful and widely used as a film with good WVTR, usually in combination with non-woven polymers (for use in diapers, devices for incontinent adults, feminine hygiene items, composite materials for household blankets, and roofing materials), it had some limitations that were well known in the industry. Among these limitations is a practical limitation on thickness (also expressed as basis weight) since conventional Ziegler-Natta catalyst polymers, more specifically film formulations highly filled with linear low density polyethylene (LLDPE) can not generally stretch to less than 3 thousandths of an inch The most obvious problem with such a limitation is that the user of the film can not make a product that uses a thinner film, meaning that the cost of the film (usually sold on a weight basis) may be higher than necessary for the application. A less obvious aspect is that at lower thicknesses, for the same resin density at the same filler loading, the product would be relatively softer than at higher thicknesses, an attribute of importance in any article that comes in contact with humans, such as clothing. Another limitation of prior polyethylene-filler films is that for a given filler loading, with conventional Ziegler-Natta catalyzed polyethylene resins, it is the WVTR, limited (at the upper end) by the amount of post-extrusion orientation that It can be achieved practically. Additionally, imperfections often found in conventional ZN resins and films, such as gels, make it difficult to achieve and maintain a high production speed, and a high level of orientation can often lead to breaks, holes or tears in the film, leading to at lower production speeds. Yet another limitation of conventional Z-N filled and oriented films is related to both WVTR and production speeds. Specifically, with a given conventional filled polyethylene, to achieve a certain WVTR, a certain filling load had to be used. In general, within certain limits, the higher the filling load, the more difficult it is to process (the problems of production referred to above, such as the creation of large voids and tears are exacerbated by a greater filling load, since the film manufacturer seeks to maximize production speeds). US Patent 4,777,073 suggests that permeability and strength of polyethylene / filler blends can be achieved by combining an LLDPE described as being done using Ziegler-Natta or chromium catalysts, with fillers such as CaCo3 present in the LLDPE from 15 to 35% by volume, which is equivalent to 34-62% by weight. Therefore, there is a commercial need for a combination of polyethylene and filler that a greater WVTR at a given filler loading, at an equivalent thickness. There is a similar need for a combination of polyethylene and filler that can provide a WVTR equivalent to lower filler loads and that can be made at a lower basis weight than a conventional combination of polyethylene Z-N / filler. Compendium It has been discovered that making a film from a polyethylene / filler combination using a metallocene-catalyzed polyethylene surprisingly and unexpectedly provides the ability to achieve a substantially higher WVTR (at a comparable filler loading and thickness), a lower thickness (or basis weight) (at a comparable filling load and orientation), and that can achieve a WVTR equivalent to lower filler loads (improving processing capacity) when compared to a polyethylene combination ZN / conventional filling. The metallocene-catalyzed polyethylenes (m-polyethylene) will have a molecular weight distribution (defined as the ratio of heavy to numerical weight average molecular Mw / Mn) generally less than 3, preferably less than 2.5. The stretch of a filled m-polyethylene will be greater than 10, preferably greater than 20, more preferably greater than 30% less than the final stretch of a filled polyethylene ZN, where the ratio in the polyethylene ZN filling between the filling amount and the base weight (minimum) for films follows the general equation: W = 2.10 + 0.280 (% by weight of CaCO3) where W is the minimum basis weight in g / m2 in the film. The ratio is 103.6M to constant stretching (direction transversal to orientation or TD) of 2.7: 1, line speed of 103.6 meters (340 feet) per minute. For formulations of filled m-polyethylene, apply the following general equation: W = 3.07 + 0.207 (% by weight of CaCO3).

Additionally, the water vapor transmission rate (WVTR) of a filled m-polyethylene is at least 10% larger, preferably at least 20%, more preferably at least 30% larger than a filled ZN polyethylene, at the same filler loading and same thickness (basis weight ), where the ZN polyethylene WVTR / filler is described by the equation: WVTR = -10,900 + 320 (% by weight of CaCO3) where the WVTR is in g / m2 / 24 hours, measured at 37.8 ° C, 90% of Relative humidity (RH). Although a film that includes an m-polyethylene and filler follows the general equation: WVTR = -9.967 + 358 (% by weight of CaC03) The ratio is to constant stretching (TD orientation) of 2.7: 1, line speed of 103.6 meters (340 feet) per minute. BRIEF DESCRIPTION OF THE DRAWINGS The above aspects, features and advantages of the present invention will be clearer and more fully understood when the following detailed description and the appended claims are read in conjunction with the accompanying drawings, in which: Figure 1 illustrates the advantage of stretching m-polyethylene filler over polyethylene ZN with a graph of minimum basis weight in g / m2 versus filler loading. Figure 2 illustrates the advantage of W-VTR of m-polyethylene versus polyethylene. Z-N is a plot of WVTR versus percent fill of CaCO3, both at a stretch ratio of 2.7: 1 and a basis weight of 22 g / m2. Detailed Description Introduction This invention concerns certain polyethylene / filler films having high WVTR and the ability to be stretched at low base weights and methods for making them. Particularly useful in these films and these methods are the m-polyethylenes. Also contemplated are m-polyethylene and filler films that can be made with smaller amounts of filler and still achieve the same WVTR as the previously known and used combinations of polyethylene Z-N / filler (at higher filler loads). This invention also includes certain m-polyethylenes, their conversion to manufactured articles such as films, articles made from such films, and applications in which such articles are desirable having a high WVTR combined with good physical properties. The resulting films, and film composites (including co-extruded and laminated films) have combinations of properties that render them superior and unique to previously available films or film composites. Filled m-polyethylene films disclosed herein are particularly suitable for use in the production of certain kinds of films with high WVTR, consumer and industrial articles that use the films in combination with, for example, woven or non-woven polymeric materials. tissues. Such consumer items include, but are not limited to diapers, incontinent adult devices, feminine hygiene articles, medical and surgical gowns, medical bandages, industrial garments, construction products such as household blankets and roofing components, made using one or more of the films disclosed herein. Additionally, films having increased WVTR of the present invention can also be used in metallized films with high WVTR, according to the disclosure of US Patent 5,055,338. Domestic Blankets Fabrics laminated suitably to the breathable film in the domestic blanket of the present invention include any high-strength fabric that can be bonded to the breathable film without adversely affecting the water vapor permeability or the air permeability resistance of the film. Breathable, that is, the TV should generally have a properly open mesh to avoid substantial blocking of the micropores of the breathable film. The fabric can be woven of any suitable material, but preferably it is a non-woven polyolefin such as, for example, low density polyethylene, polypropylene, and preferably linear low density polyethylene or linear high density polyethylene. The fabric should have an elongation (ASTM D1682) of less than 30%, an Emendorf tear resistance (ASTM D689) of at least 300 g, preferably at least 600 g, and especially at least 900 g; and a rupture load (ASTM D1682) of at least 13 kg / cm (15 lb / in), preferably at least 21.6 kg / cm (25 lb / in), and especially at least 26 kg / cm (30 lb. / in). It is believed that these fabrics are prepared from HDPE films having coextruded ethylene vinyl acetate outer layers on each side of the HDPE or thermo-sealed layers. The films are fibrillated, and the resulting fibers are spread in at least two transverse directions to a filament count of 2.366 per cm (6.010 per inch). The spread fibers are then cross-laminated by heat to produce a nonwoven fabric of 76.2-127 μm (3-5 mils) with equal MD and TD strength. These fabrics have excellent strength properties in both MD and TD to reinforce the breathable film, an open structure to avoid substantially blocking the micropores of the breathable film when laminated to it, and an outer layer of the ethylene vinyl acetate copolymer for capacity of thermal sealing. The fabric and the breathable film are laminated together to form the breathable composite of the invention. The lamination can be effected by arranging the film and the fabric together, looking at each other, and applying heat and pressure. The lamination temperatures to which the film and the fabric are exposed should be sufficient to achieve the lamination, but they should not be so high as to prevent the flow of the film polymer into the microporous spaces and the consequent reduction in the capacity of the film. water vapor transmission. In a preferred embodiment, the fabric is heated on a hot roll, preferably at 93.3-115.5 ° C (200-240 ° F) and then pressed, preferably at a pressure of 3.4 to 6.8 atmospheres (50 to 100 psi). ), towards contact with the unheated film to bond the fabric and the film in a laminate. Preferred fabrics are commercially available under the trade designations DD1001, CC-2001 and CC-3001 CLAF of non-woven HDPE fabrics. Filled m-polyethylene films, when oriented after film formation, would surprisingly and unexpectedly have a high WVTR compared to a filled polyethylene film made using previously available Z-N catalyzed polyethylenes. The following is a detailed description of certain preferred m-polyethylenes, films or film composite materials made using these m-polyethylenes and articles made from the films or composite film materials, which are within the scope of the present invention. invention. Those skilled in the art will appreciate that numerous modifications can be made to these preferred embodiments without departing from the scope of the invention. For example, although films based on low density m-polyethylenes filled with CaCO3 are exemplified herein, the films can be made using combinations of m-polyethylenes with other polyolefins and with other fillers or filler combinations. To the extent that the description is specific, it is solely for the purpose of illustrating the preferred embodiments of the invention and should not be taken as limiting the present invention to these specific embodiments. Production of the Films The films contemplated by the present invention can be made using m-polyethylenes, by processes including blowing and forging, with a forged film process being preferred. In such extrusion processes, the films of the present invention can be formed into a single layer film, or can be a layer or more of a multi-layer film or a film composite. Alternatively, the m-polyethylene films described in this disclosure can be formed or used in the form of a physical resin mixture where the physical mixture components can function to modify the WVTR, the physical properties, the stretch seal, the cost, or other functions. Both components of physical mixture and the functions provided by them will be known to those skilled in the art. The films of the present invention can also be included in laminated structures. As long as a film, multilayer film or laminated structure includes one or more layers of m-polyethylene film / filler having the WVTR or the stretch and similar properties of the film, and the ratio Mw / Mn, the CDBI or m-polyethylene, in the ranges described herein, will be understood to be contemplated as an embodiment of the present invention. Polyolefin Component The polyolefin component can be any polyolefin or physical blend of film-forming polyolefins, while the greater part of the polyolefin component is a polyolefin with the following characteristics: Generally, these ranges dictate the use of a metallocene-catalyzed polyolefin, with m-polyethylene being preferred, preferably linear low-density m-polyethylene, with a density in the range of 0.90 to 0.940, preferably 0.910-0.935, more preferably 0.912. -0.925 g / cc. The densities referred to herein will generally be polymer or resin densities, unless otherwise indicated. There is a wide variety of commercial and experimental m-polyethylene resins useful in the manufacture of films included in certain embodiments of the present invention. A non-inclusive list is found below, along with the general properties of bulk resin, as published: Table A * available from Exxon Chemical Company, Houston, Texas, USA. UU + Exceed® 357C32 is the same grade of resin as ECD-112 and ECD-115 used in the experiments. It will be generally understood that it is contemplated that a large number of m-polyethylenes will be useful in the techniques and applications described herein. The components included are: ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene and dodecene copolymers, ethylene copolymers -1-pentene, as well as ethylene copolymers of one or more alpha-olefins, diolefins or their combinations C4 to C20- A non-exclusive list of such polymers: ethylene, 1-butene, 1-pentene; etiene, 1-butene, 1-hexene; ethylene, 1-butene, 1-octene; ethylene, 1-butene, decene; ethylene, 1-pentene, 1-hexene; ethylene, 1-pentene, 1-octene; etiieno, 1-pentene, decene; ethylene, 1-octene, 1-pentene; ethylene, 1-octene, decene; ethylene, 4-methyl-1-pentene, 1-butene; ethylene, 4-methyl-1-pentene, 1-pentene; ethylene, 4-methyl-1-pentene, 1-hexene; ethylene, 4-methyl-1-pentene, 1-octene; ethylene, 4-methyl-1-pentene, decene. Included in the ethylene copolymers will be one or more of the above monomers included at a total level of 0.2 to 6 mol%, preferably 0.5 to 4 mol%, or such molar percentages consistent with the resin densities contemplated. The resin and product properties defined in this description were determined in accordance with the following test procedures. Where any of these properties is referred to in the appended claims, it must be measured according to the specified test procedure. Table B Filler The fillers useful in this invention may be any inorganic or organic material having a low affinity for and a considerably lower elasticity than the polyolefin component. Preferably, the filler must be a rigid material having a non-smooth hydrophobic surface, or a material that is treated to hydrophobize its surface. The average average preferred particle size of the filler is between 0.5 and 5 microns for films generally having a thickness between 1 and 6 mils before stretching. Examples of inorganic fillers include calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, aluminum hydroxide, zinc oxide, hydroxide of magnesium, calcium oxide, magnesium oxide, titanium oxide, alumina, mica, glass powder, zeolite, silica, etc. The calcium carbonate is preferably surface treated to be hydrophobic so that the filler can repel water to reduce agglomeration thereof. Also, the surface coating should improve the ligation of the filler to the polymer while allowing the filler to be removed from the polyolefin under tension. A preferred coating is calcium stearate, which meets the standards of the Federal Drug Administration of the United States and is widely available. Organic fillers such as wood powder and other cellulose powders can be used. Polymer powders such as Teflon® and Kevlar® powder can also be used. The amount of filler added to the polyethylene depends on the desired properties of the film, including shear strength, water vapor transmission rate, and stretch capacity. However, it is believed that a film with good WVTR generally can not be produced as taught herein with a fill amount of less than 20% by weight of the polyolefin / filler composition. The minimum amount of filler is necessary to ensure the interconnection within the film of voids created at the filler site, particularly by the filling operation to be carried out subsequently on the precursor film. Furthermore, it is believed that useful films can not be made with an amount of filler in excess of 70% by weight of the polyolefin / filler composition. Higher amounts of filler can cause difficulties in combining and considerable losses of strength in the final breathable film. Although a wide range of fillers has been described in a wide range of inclusion parameters based on percentages by weight, other embodiments are contemplated. For example, fillers with much greater or lesser specific gravities can be included in the polyolefin in amounts outside the disclosed weight ranges, they will be considered as embodiments of the invention as long as the final film, after orientation, has a WVTR or a stretch similar to those described herein. Stretching or Orientation and Thermo-Setting The final preparation of a breathable film is achieved by stretching the filled m-polyethylene precursor film to form interconnected voids. Stretching or "orientation" of the film can be carried out monoaxially in the machine direction (MD) or in both directions (biaxially), either simultaneously or sequentially using conventional equipment and processes after cooling the precursor film. The orientation of the film can also be carried out on a tenter device with or without MD orientation to impart TD orientation to the film. The film is grasped at the edges for processing through the tenter device. The stretching of melt-engaged precursor films with a tenter device at a film speed of 60 to 152.4 meters (200-500 feet) per minute produces breathable films having the desired water vapor permeability. The resulting films had a higher permeability in areas of reduced thickness compared to areas of greater thickness. A range of stretching ratios of 2: 1 to 5: 1 is satisfactory for MD stretching, with a 4: 1 ratio being preferred. A range of stretching ratios of 2: 1 to 5: 1 is satisfactory for TD stretching, with a 3: 1 ratio being preferred. It is preferred that the tension be maintained on the film during heat-setting and cooling to minimize retro-shrinkage. When cooling to room temperature (ie, room temperature) or close to the ambient temperature, the clamping force can be released. The film can be caught somewhat (retro-fit elastic) in TD but will retain a substantial portion of its stretched dimension. The thermosetting can be achieved by keeping the film low tension in the stretched condition at the thermoset temperature for 1-2 minutes. Preferably, however, thermosetting and cooling are carried out while allowing the film to contract slightly, but still under tension. The controlled retro-shrinkage of 5 to 30%, preferably between 15 and 25%, of the maximum stretched width has yielded particularly good results by eliminating shrinkage in storage. Properties of Films Produced from the WVTR Resins Certain films of the present invention and articles made therefrom have a WVTR higher than previously thought possible. The WVTR of such films should be over 100 g / m2 / day at 37.8 ° C, 90% RH, preferably over 1, 000, more preferably over 3,000 g / m2 / day at 25 ° C. This can be seen in Figure 2, which illustrates the WVTR advantage of m-polyethylene versus polyethylene Z-N on a graph of WVTR versus percentage of CaC03 filler.

In general, the films of embodiments of the present invention will have a much higher WVTR at the same filler loading as previously known Z-N polyethylene-filled films. Specifically, the films of the invention will have a WVTR at least 10% higher than the WVTR of the comparative films described by the equation: WVTR = -10,900 + 320 (% by weight of CaCO3). In another embodiment of the invention, a m-polyethylene / filler combination film can be stretched (oriented or laid on the TD) smaller than a polyethylene combination film ZN, and still substantially achieve the same WVTR (a generally same filler loads). This is a significant advantage to a film manufacturer because the more orientation, the greater the possibility of amplifying an imperfection of the film, potentially causing a catastrophic failure (rupture). It is not beyond the scope of the embodiments of the invention to physically mix the m-polyolefins to form the films of the invention with other materials such as other linear polyethylenes (HDPE, MDPE, LLDPE), polyethylene low density (LDPE), polypropylene (PP) (homopolymers and copolymers), polybutene-1 (PB), ethylene vinyl acetate (EVA), or other copolymers of polar co-monomer of ethylene and the like, to make useful articles. Such potential physical mixture polyolefins can be conventional Ziegler-Natta catalysts, catalyzed with chromium, initiated by free radicals, and the like. However, the WVTR of the layer or layers intended to impart WVTR should generally be within the limits disclosed above. Additionally, any component of physical mixture or additive or component additives should be selected such that the desired WVTR of the film remains at or above the target or desired value. Any physical mixture preferably must contain a majority of m-polyethylene as a polyolefin component, specifically more than 50% by weight, preferably more than 60% by weight, more preferably more than 70%, based on the total weight of the polyolefin. Definitions and Test Protocols Test Methods Water Vapor Transmission Rate The WVTR test measures the amount of water vapor that is capable of passing through a film. A Mocon Permatran W-1 unit is used to measure the WVTR by passing a stream of dry air through the surfaces of the film. The dry air picks up the moisture that has passed, from wet pads under the film, through to the top surface. The humidity level is measured by an infrared (IR) detector and converted into a voltage that can be measured in a plotter. The procedure also includes: a) punching a die-cut hole in an aluminum foil mask, b) cutting two opposite corners of the mask, c) peeling off the backing paper from the mask, d) cutting out boxes of 5.08 x 5.08 cm (2"x 2") of film and place them over the hole in the mask, e) place the backing of paper back on the sheet mask, then f) place the masked sample in the test cell with the side of aluminum up. The plotter reading is multiplied by 100 to give the WVTR value. Gurley porosity The Teleyn Gurley porosity tester model 4190, with sensitive junction, is used. The procedure is as follows: a) cut a strip of film (approximately 5.08 cm (2") in width across the entire screen width, b) insert a film sample to be tested between orifice plates, c) fix the adjustment of sensitivity at "5", d) turn the inner cylinder so that the timer eye is centered vertically below the silver pitch of 10 ce in the cylinder, e) reset the timer to zero, f) pull the spring out of the upper tab and release the cylinder.When the timer stops counting, the test is completed. The number of accounts is multiplied by 10 and the resulting number in "seconds Gurley by 100 ce". It will be appreciated by those skilled in the art that the m-polyethylene resin films of certain embodiments of the invention may be combined with other materials, depending on the intended function of the resulting film. Other methods of improving and / or controlling the WVTR properties of the film or container may be used in addition to the methods described herein, without departing from the intended scope of the invention. For example, mechanical treatment such as micropores. Stretching The embodiments of the present invention offer a significant and unexpected improvement in the ability of the formulations to be stretched. Specifically, using conventional Ziegler-Natta polyethylenes, a lower limit of 63.5 (2.5), more practically 88.9 μm (3.5 thousandths of an inch) upstream (as extruded) has been routinely observed, ie before orientation. In contrast, films of embodiments of the present invention can be stretched to a practical limit of 5.08 μm (2 mils), providing a significant advantage in terms of either economy or a combination of economy and smoothness. The softness arises due to the reduced module of the lower thickness. The final stretch is defined as the minimum caliper (or basis weight) before the emergence of stretch resonance at a given extruder rate (eg, kg / hr (lb / hr)). The films of embodiments of the present invention will have a final stretch of more than 20%, preferably 25%, more preferably 30% less than that of the filled ZN polyethylene which, from FIG. 2, has a stretch final described by the general formula: W = 2.1 + 0.380 (% by weight of CaCO3). Examples All polyethylene / filler materials were stabilized to decrease the effects of extrusion. The orientation of all the above examples was carried out at a draw ratio of 2.7: 1, at 10.66 meters per minute (35 feet per minute), 68.5-104.4 ° C (150-220 ° F) laying temperature, 82.2-110 ° C (180-230 ° F) hardening temperature. Examples 1-3 Examples 1-3 were manufactured from Escore-ne ™ LL 3003.09 on a forged extrusion line of 15.24 cm (6 inches) Marshall &; Williams under the normal processing conditions listed in Table la. Example 1 used a 50/50 ratio of polyethylene to CaCO3, while Examples 2-3 used a 65/35 ratio of polyethylene to filler. All films were subsequently oriented (TD) to three different base weights, as shown in Table 1. Examples 4-9 Examples 4-9 were manufactured from Exceed® ECD-112, under the same processing conditions as Examples 1-3. Examples 4-6 used a 50/50 weight ratio of polyethylene to CaCO3, while Examples 7-9 used a 65/35 polyethylene to fill ratio. All films were subsequently oriented (TD) to three different base weights, as seen in Table 2. From the data in Table 1 for each of these runs of the Examples, it can be seen that in Examples 1 and 2, by lowering the fill level, the WVTR drops dramatically; and as seen in Example 3, a lower basis weight only marginally increases the WVTR of the film with a higher percentage of polyethylene. In contrast, from Table 2 for Examples 4-9, a much higher WVTR is achieved by the same filler load and the same basis weight as for the films of Examples 1-3; Moreover, although a higher percentage of polyethylene in the formulation (Examples 4-6 versus 7-9) generates a decrease in the WVTR, the percentage is much lower than that experienced for the polyethylene ZN of Examples 1-3 (reduction of the 95 versus 68%). Examples 10-15 Examples 10-15 are run as Examples 4-9, but the polyolefin component was a physical mixture of LD-202 (12-MI low density polyethylene, 0.917 g / cc, available from Exxon Chemical Company ) and ECD-112. As can be seen from the data in Table 3, at the same basis weight as Examples 4-6 and 7-9, the corresponding films of Examples 10-15 had a somewhat smaller but still acceptable WVTR. Also of note is example 15, which was the lowest base weight to be achieved in this series (1-15) of examples (again the orientation was TD). Examples 16-23 Examples 16-23 were extruded under conditions similar to the previous examples, in two thicknesses of precursor film (before orientation) of 114-3-152.4 μm (4.5 and 6 mils) and MD oriented to 79.4 ° C (175 ° F). Although the WVTR results for this set of examples appear to be substantially the same for both metallocene-catalyzed polyethylenes and ZN, it is anticipated that when the orientation speed is increased, the m-LLDPE will show an improved WVTR, over the ZN-LLDPE, just as it is in the TD orientation in Examples 1-15. The results are shown in Tables 4 and 5. Examples 24-25 Examples 24 and 25 were extruded under substantially the same conditions as the previous examples. He Example 24 is substantially the same in polyethylene / filler content as Example 4 and Example 24 is substantially the same formulation as Example 1. Example 24 was stretched (oriented) at a stretch ratio of 2.7: 1, while Example 25 was stretched at a 3.8: 1 ratio. These examples show that the m-LLDPE a lower stretch ratio (28%) than the Z-N-LLDPE, Example 24, generally has the same WVTR. The results are shown in Table 6. Although the present invention has been described and illustrated with reference to its particular embodiments, those skilled in the art will appreciate that the invention lends itself to variations not necessarily illustrated herein. For example, it is not beyond the scope of this invention to include additives with the claimed films or physically mix resins to form the claimed films with other polymers or laminate the claimed films to other materials such as polymeric non-wovens and the like. Therefore, for this reason, reference should be made only to the appended claims for purposes of determining the true scope of the present invention. Table 1 Properties of Oriented Film Samples based on LL 3003.09 • The "DR limit", also known as "final stretch" is the basis weight at which stretching resonance was first observed. The DR probe was conducted with the mpm (fpm) fixed at 103.6 (340) and the extruder rpm gradually reduced until the emergence of stretch resonance. Table Extrusion Conditions (for samples of 22 g / m2) Condition Example 1 Example 2 Example 4 Example 7 Example 10 Example 14 RPM Ext. 23.0 26.4 19.1 21.6 29.5 31 Current 23.99 (3480) 25.78 (3740) 25.71 (3730) 31.919 (4630) 30.590 (4430) Up kPa xl03 (psi) Current 9.31 (1310) 8.75 (1270) 1160 7.997 (1630) 10.272 (1490) Down kPa xl03 (psi) Terap. Fus. , ° C 219.4 (427) 224.4 (436) 221.1 (430) 221.67 (431) 236.6 (458) 232.78 (451) (° F) Width 9.2 (23.4) 9.17 (23.3) 8.58 (21.8) 8.58 (21.8) 12.24 ( 31.1) 11.96 (30.4) above, cm (in) Width 23.97 (60.9) 24.64 (62.6) 24.44 (62.1) 34.0 (86.4) - bottom, cm (in) Roll Forged 96.92 (318) 103.93 (341) 103.63 (340) 103.63 (340) 103.32 (339) 103.63 (340) Ratio is stretch for all the examples set as a target to 2.7: 1 (ratio of the output width divided by the width of the input).

Table 2 Properties of Oriented Film for Exceed® Based Samples ECD-112 • The "DR limit", also known as "final stretch" is the basis weight at which stretching resonance was first observed. The DR probe was conducted with the mpm (fpm) fixed at 103.6 (340) and the extruder rpm gradually reduced until the emergence of stretch resonance.

Table 3 Properties of Oriented Film for Exceed®-Based Samples? CD-112 Physically Mixed with LDPE (LD-202) • The "DR limit", also known as "final stretch" is the basis weight at which stretching resonance was first observed. The DR probe was conducted with the mpm (fpm) fixed at 103.6 (340) and the extruder rpm gradually reduced until the emergence of stretch resonance.

Table 4 Orientation at 175 ° F Precursor Film of 114.3 μm (4.5 mils) Note: all samples oriented with an entry speed of 4.6 mpm (15 fpm), tempering of 87.78 ° C (190 ° F) and relaxation of 5%.

Table 5 Orientation at 79.44 ° C (175 ° F) Precursor Film 152.4 μm (6.0 mils) Note: all samples oriented with an entry speed of 4.6 mpm (15 fpm), tempering of 87.78 ° C (190 ° F) and relaxation of 5%.

Table 6

Claims (8)

1. CLAIMS 1. A process for making a domestic blanket, comprising: a) mixing a polyolefin with a filling; b) extruding a film from the polyolefin / filler mixture; c) engargolar in the molten state the film of b), to impose on it a pattern of different film thickness; d) stretching the melt-engaged film of c) to impart a higher water vapor transmission rate; and e) laminating the stretched film to a nonwoven fabric comprising fibers transversely laminated at a temperature and pressure sufficient to bind the fabric and the film to form a breathable laminate, characterized in that said polyolefin includes at least a majority of a polyethylene having a ratio Mw / Mn - < 3, and an amplitude index of compositional distribution of more than 60%; where the film will have a water vapor transmission rate at least 10% higher than the WVTR described by the equation: WVTR = -10,900 + 320 (% by weight filler) (at a stretch ratio of 2.7: 1 and weight base of 22 g / m2) measured at 37.8 ° C and 90% relative humidity. The method of claim 1, further comprising thermosetting the melt-bonded film, stretched at a temperature above the draw temperature and below the softening temperature of the melt-entangled, drawn film; wherein said lamination is selected from the group consisting of thermo-lamination, adhesive lamination, extrusion lamination, mechanical bonding, and combinations thereof; wherein the polyolefin is a copolymer of ethylene and a C4-C10 alpha-olefin having a Mw / Mn 2.5 ratio; wherein said filler is calcium carbonate surface treated with calcium stearate; where the film of b) is engargolada in the molten state with a diamond pattern; and wherein the polyolefin / filler mixture of a) contains between 30 and 65% filler by weight based on the total weight of said mixture. The method of any of the preceding claims, wherein the fabric is a nonwoven polyolefin fabric having a thermal seal layer. 4. The method of claim 3, wherein the lamination comprises heating the fabric and pressing the non-hot film to the hot fabric. The process of any of the preceding claims, wherein the polyolefin / filler blend of a) contains between 30 and 65% by weight filler. 6. The process of any of the preceding claims, wherein said film has a WVTR of at least 20% greater than the WVTR described by the equation: WVTR = -10,900 + 320 (% by weight of filler) (at a stretch ratio of 2.7 : 1 and base weight of 22 g / m2). The process of any of the preceding claims, wherein said film has a WVTR of at least 30% greater than the WVTR described by the equation: WVTR = -10,900 + 320 (% by weight filler) (at a stretch ratio of 2.7: 1 and base weight of 22 g / m2). 8. A domestic blanket made from any of the preceding claims.