Female hygiene articles and films with improved softness and handfeel

Abstract

Disclosed is a feminine hygiene article comprising a film having at least a first layer and optionally a second layer, the first layer comprising at least 25% by weight of an ethylene acrylate copolymer based on the total weight of the first layer and less than 75% by weight of a polyolefin based on the total weight of the first layer. The first layer may have a gloss of less than 30% as measured by ASTM D2457 at 45 DEG C and a drapability of less than or equal to 10.0 gf in both the machine direction or the transverse direction as measured according to WSP 90.3. The ethylene acrylate copolymer may contain 16% to 35% by weight of acrylate based on the total weight of the ethylene acrylate copolymer. Thus, feminine hygiene articles comprising a soft film having a non-plastic appearance but with high tensile strength, low elongation as well as high tear and puncture resistance as well as high modulus can be obtained.

Description

Technical Field

[0001] The present disclosure relates generally to feminine hygiene articles. More specifically, the present disclosure relates to feminine hygiene articles comprising a polyolefin film comprising an ethylene acrylate copolymer. Background Art

[0002] Feminine hygiene products contact one of the most sensitive parts of the human anatomy. Therefore, the feminine hygiene market values ​​items that have a cotton or silk-like feel and appearance, despite the fact that they are produced using polyethylene or polypropylene. Feminine hygiene products and other sanitary products must also absorb and retain liquids during daily activities. Therefore, high tensile strength, low elongation, high puncture and tear resistance, and high modulus are also important. These ensure the strength, stability, and printability of the final manufactured product.

[0003] Feminine hygiene products may include a three-layer pad or a four-layer pad. A three-layer pad may include a permeable top sheet, an absorbent core, and an impermeable back sheet. A four-layer pad may include a permeable top sheet, a transfer layer, an absorbent core, and an impermeable back sheet.

[0004] Softness can be improved by reducing the thickness of the film coating the absorbent core of the sanitary article. Softness can also be improved by reducing the density of the polyethylene used. However, this significantly affects the mechanical strength and greatly increases the elongation, which makes printing and product assembly difficult.

[0005] Reduced gloss and increased opacity resulting in a non-plastic appearance are usually achieved by adding pigments and in-line or off-line embossing. However, this is often difficult, especially in perforated films such as ADLs or topsheets.

[0006] Therefore, there is a continuing need for feminine hygiene articles comprising soft films having high tensile strength, low elongation, as well as high tear and puncture resistance and a non-plastic appearance with high modulus. Summary of the invention

[0007] A feminine hygiene article is disclosed comprising a film having at least a first layer and an optional second layer, the first layer comprising at least 25 weight percent, based on the total weight of the first layer, of an ethylene acrylate copolymer and less than 75 weight percent, based on the total weight of the first layer, of a polyolefin. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The drape of the inventive and comparative examples in both the machine and cross machine directions is graphically depicted, as measured using a hand tester according to WSP 90.3.

[0009] Figure 2The average dynamic coefficient of friction and the average static coefficient of friction measured according to ASTM 1894 for the inventive and comparative examples are graphically depicted.

[0010] Figure 3 The gloss at 45° measured according to ASTM D2457 is graphically depicted for both Inventive and Comparative Examples.

[0011] Figure 4 Contains enlarged photographs of reflected light at the film surface of both the inventive example and the comparative example.

[0012] Figure 5 The tensile strength at break of the inventive examples and comparative examples measured according to ASTM D882 in both the machine direction and the transverse direction is graphically shown.

[0013] Figure 6 The elongation at break in both the machine direction and the transverse direction measured according to ASTM D882 for the inventive examples and comparative examples is graphically shown.

[0014] Figure 7 The Elmendorf Tear in both the machine direction and the cross direction as measured according to ASTM D1922 is graphically shown for both the Inventive Examples and the Comparative Examples.

[0015] Figure 8 The puncture resistance of the inventive examples and comparative examples measured according to ASTM D5748 is graphically shown. DETAILED DESCRIPTION

[0016] A film having at least a first layer comprising at least 25% by weight of an ethylene acrylate copolymer will now be disclosed in detail in the following description and examples. A feminine hygiene article comprising the disclosed film is also disclosed, the film having at least a first layer comprising at least 25% by weight of an ethylene acrylate copolymer. A feminine hygiene article comprising the disclosed film and a nonwoven is also disclosed, the film having at least a first layer comprising at least 25% by weight of an ethylene acrylate copolymer.

[0017] The term "polymer" refers to a polymeric compound prepared by polymerizing monomers, whether of the same or different types. Thus, the general term polymer encompasses the term "homopolymer," which is generally used to refer to polymers prepared from only one type of monomer, and "copolymer," which refers to polymers prepared from two or more different monomers. The term "interpolymer," as used herein, refers to a polymer prepared by the polymerization of at least two different types of monomers. Thus, the general term interpolymer includes copolymers and polymers prepared from more than two different types of monomers, such as terpolymers.

[0018] As used herein, "polyolefin" refers to an olefin-based polymer. As used herein, "olefin", which may also be referred to as "alkene", refers to a linear, branched or cyclic compound comprising carbon and hydrogen and having at least one double bond. As used herein, when a polymer or copolymer, such as a polyolefin elastomer, is referred to as comprising an olefin, the olefin present in the polymer or copolymer is the polymerized form of the olefin. For example, when a polyolefin elastomer is said to have an ethylene content of 75% to 85% by weight, it is understood that the polymer units in the polyolefin elastomer are derived from ethylene in the polymerization reaction, and the derived units are present in 75% to 85% by weight based on the gross weight of the polyolefin elastomer.

[0019] As used herein, the term "polyethylene" refers to a polymer comprising greater than 50% by weight of units derived from ethylene monomers, and optionally one or more comonomers. This may include polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); single-site catalyzed linear low density polyethylene, including both linear and substantially linear low density resins (m-LLDPE); medium density polyethylene (MDPE); and high density polyethylene (HDPE).

[0020] As used herein, the term "ethylene acrylate copolymer" refers to a copolymer comprising, in polymerized form, a majority amount of ethylene monomer (based on the weight of the copolymer) and an alkyl acrylate.

[0021] As used herein, the term "meltblown" refers to the manufacture of nonwoven fabrics via a process generally comprising the following steps: (a) extruding molten thermoplastic strands from a spinneret; (b) using a heated high-speed air stream to simultaneously quench and attenuate a polymer stream immediately below the spinneret; (c) collecting the stretched strands into a web on a collecting surface. Meltblown webs can be bonded by a variety of means, including but not limited to autogenous bonding (i.e., self-bonding without further processing), thermal calendering processes, adhesive bonding processes, hot air bonding processes, needle punching processes, hydroentanglement processes, and combinations thereof.

[0022] As used herein, the term "spunbond" refers to the manufacture of a nonwoven fabric comprising the following steps: (a) extruding molten thermoplastic strands from a plurality of fine capillaries called spinnerets; (b) quenching the strands with a generally cooled air stream to accelerate solidification of the molten strands; (c) drawing the strands by advancing the strands through a quenching zone with a drawing tension, which may be applied by pneumatically entraining the strands in an air stream or by winding the strands around a mechanical drawing roller of the type commonly used in the textile fiber industry; (d) collecting the drawn strands into a web on a small-forged surface, such as a moving screen or a porous belt; and (e) bonding the web of loose strands into a nonwoven fabric. Bonding can be achieved in a variety of ways, including but not limited to thermal calendaring processes, adhesive bonding processes, hot air bonding processes, needle punching processes, hydroentanglement processes, and combinations thereof.

[0023] As used herein, the terms "nonwoven," "nonwoven web," and "nonwoven fabric" are used interchangeably herein. "Nonwoven" refers to a web or fabric having a structure of individual fibers or threads that are randomly interlaced rather than in an identifiable pattern as in a knitted fabric.

[0024] Membrane composition and properties

[0025] The disclosed first layer of the film may include at least 25% by weight of ethylene acrylate copolymer based on the total weight of the first layer. Ethylene acrylate copolymers include, but are not limited to, ethylene methyl acrylate copolymers, ethylene ethyl acrylate copolymers, or ethylene n-butyl acrylate copolymers. For example, the first layer may include at least 25% by weight of ethylene methyl acrylate copolymers, ethylene ethyl acrylate copolymers, or ethylene n-butyl acrylate copolymers. The first layer may include at least 50% by weight of ethylene acrylate copolymers based on the total weight of the first layer. The first layer may include less than or equal to 75% by weight of ethylene acrylate copolymers based on the total weight of the first layer. The first layer may include 25% to 75% by weight of ethylene acrylate copolymers based on the total weight of the first layer. All individual values ​​and subranges are disclosed. For example, the first layer may include 35% to 65% by weight of ethylene acrylate copolymers based on the total weight of the first layer. The first layer may include 45% to 55% by weight of ethylene acrylate copolymers based on the total weight of the first layer.

[0026] The disclosed first layer may include less than 75% by weight of polyolefin based on the total weight of the first layer. The first layer may include less than 50% by weight of polyolefin based on the total weight of the first layer. The first layer may include less than 25% by weight of polyolefin based on the total weight of the first layer. The first layer may include 25% to 75% by weight of polyolefin based on the total weight of the first layer. All individual values ​​and subranges are disclosed. For example, the first layer may include a lower limit of 25%, 35%, 45%, 55%, 65% or 70% by weight to an upper limit of 75%, 70%, 65%, 55%, 45%, 35% or 30% by weight of polyolefin based on the total weight of the first layer.

[0027] The first layer may also include white pigment. The first layer may include at least 5 wt % white pigment based on the total weight of the first layer. The first layer may include at least 5 wt % to 20 wt % white pigment based on the total weight of the first layer. All individual values ​​and subranges from 5 wt % to 20 wt % are included and disclosed. For example, the first layer may include 10 wt % to 20 wt % white pigment based on the total weight of the first layer. The first layer may include 15 wt % to 20 wt % white pigment based on the total weight of the first layer.

[0028] The first layer may also include calcium carbonate. The first layer may include at least 5 wt % calcium carbonate based on the total weight of the first layer. The first layer may include 5 wt % to 15 wt % calcium carbonate based on the total weight of the first layer. All individual values ​​and subranges of 5 wt % to 15 wt % are included and disclosed. For example, the first layer may include 5 wt % to 10 wt % calcium carbonate.

[0029] The first layer may have a gloss of less than 40% as measured by ASTM D2457 at 45°. The first layer may have a gloss of less than 30% as measured by ASTM D2457 at 45°. The first layer may have a gloss of less than 20% as measured by ASTM D2457 at 45°. The first layer may have a gloss between 10% and 40% as measured by ASTM D2457 at 45°. All individual values ​​and subranges are disclosed. For example, the first layer may have a gloss of 20% to 30% as measured by ASTM D2457 at 45°. The first layer may have a gloss of 10% to 20% as measured by ASTM D2457 at 45°.

[0030] The film may have a drape of less than or equal to 10.0 gf in both longitudinal and transverse directions as measured according to WSP 90.3. The first layer may have a drape of less than or equal to 5.0 gf in both longitudinal and transverse directions as measured according to WSP 90.3. The first layer may have a drape of less than or equal to 4.0 gf in both longitudinal and transverse directions as measured according to WSP 90.3. The first layer may have a drape of less than or equal to 3.0 gf in both longitudinal and transverse directions as measured according to WSP 90.3. The first layer may have a drape of 2.0 gf to 10.0 gf in both longitudinal and transverse directions as measured according to WSP 90.3. All individual values ​​and subranges are included and disclosed. For example, the first layer may have a drape of from a lower limit of 2.0 gf, 2.5 gf, 3.0 gf, 3.5 gf, 4.0 gf, 4.5 gf, or 5.0 gf to an upper limit of 10.0 gf, 9.5 gf, 9.0 gf, 8.5 gf, 8.0 gf, 7.5 gf, 7.0 gf, 6.5 gf, 6.0 gf, 5.5 gf, 5.0 gf, 4.5 gf, 4.0 gf, or 3.5 gf in both the machine and cross directions as measured according to WSP 90.3.

[0031] The disclosed film may further include a second layer and a third layer. The second layer and the third layer may each comprise a separate polyethylene composition.

[0032] Polymer compositions and preparation

[0033] Suitable acrylates for use in the first layer of the film include, but are not limited to, methyl acrylate, ethyl acrylate, and n-butyl acrylate. The ethylene acrylate copolymer may contain at least 16% by weight of acrylate. The ethylene acrylate copolymer may contain 16% to 35% by weight of acrylate based on the total weight of the ethylene acrylate copolymer. All individual values ​​and subranges from 16% to 35% by weight are included and disclosed. For example, the ethylene acrylate copolymer may contain 20% to 35% by weight of acrylate based on the total weight of the ethylene acrylate copolymer. Examples of commercially available ethylene acrylate resins suitable for use in the present disclosure include ELVALOY acrylate from The Dow Chemical Company, Midland, MI. TM AC 1224 or 1330.

[0034] The polyolefin of the first layer may comprise an elastomer. Such polyolefin elastomers may comprise olefin block copolymers, such as ethylene / α-olefin block copolymers. Commercial examples of ethylene / α-olefin block copolymers include those available from The Dow Chemical Company in Midland, MI, under the trade name INFUSE TM The obtained resin.

[0035] Ethylene / alpha-olefin block copolymers may include ethylene and one or more copolymerizable alpha-olefins in polymerized form, characterized in that multiple blocks or segments of two or more polymerized monomer units are different in chemical or physical properties. The polyolefin elastomer may be a multi-block copolymer. The multi-block copolymer may be represented by formula (AB) n, wherein n is at least 1, preferably an integer greater than 1, such as 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100 or more, "A" represents a hard block, and "B" represents a soft block. In contrast to a substantially branched or substantially star-shaped manner, A and B may be linked in a substantially linear manner. A blocks and B blocks may be randomly distributed along the polymer chain. Each of block A and block B may have monomers or comonomers substantially randomly distributed within the block, such that neither block A nor block B comprises two or more sub-segments having different compositions, such as a terminal segment having a substantially different composition than the remainder of the block.

[0036] Ethylene / α-olefin block copolymers may include different amounts of "hard" and "soft" blocks. "Hard" blocks refer to blocks of polymerized units, wherein ethylene is present in an amount greater than about 95% by weight and preferably greater than about 98% by weight based on the weight of the polymer. In other words, the comonomer content in the hard blocks, i.e., the content of monomers other than ethylene, is less than about 5% by weight and preferably less than about 2% by weight based on the weight of the polymer. The hard blocks may contain all or substantially all ethylene. On the other hand, "soft" blocks refer to blocks of polymerized units, wherein the comonomer content, i.e., the content of monomers other than ethylene, is greater than about 5% by weight. For example, the comonomer content may be greater than about 5%, greater than about 8%, greater than about 10%, or greater than about 15% by weight based on the weight of the polymer. The comonomer content in the soft block can be greater than about 20 wt%, greater than about 25 wt%, greater than about 30 wt%, greater than about 35 wt%, greater than about 40 wt%, greater than about 45 wt%, greater than about 50 wt%, or greater than about 60 wt%, based on the weight of the polymer.

[0037] Soft blocks can be present in ethylene / alpha-olefin block copolymers in an amount of about 1 wt % to about 99 wt % of the total weight of a polyolefin elastomer. For example, soft blocks can be present in ethylene / alpha-olefin block copolymers in an amount of about 5 wt % to about 95 wt %, about 10 wt % to about 90 wt %, about 15 wt % to about 85 wt %, about 20 wt % to about 80 wt %, about 25 wt % to about 75 wt %, about 30 wt % to about 70 wt %, about 35 wt % to about 65 wt %, about 40 wt % to about 60 wt %, or about 45 wt % to about 55 wt % of the total weight of a polyolefin elastomer. On the contrary, hard blocks can exist in a similar range. Soft blocks and hard blocks weight percentages can be calculated based on data obtained from DSC or NMR. Such methods and calculations are disclosed in U.S. Patent Application Publication No. 2006 / 0199930.

[0038] Examples of α-olefin comonomers that can be used to form the ethylene / α-olefin block copolymers include, by way of example and not limitation, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene, vinylcyclohexane, norbornadiene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene, cyclooctene, C-pentene, and the like. 4 -C 40 Diene, other C 4 -C 40 α-olefins, etc. The α-olefin comonomer may include C 3 -C 8 Comonomer content can be determined using any suitable technique such as techniques based on nuclear magnetic resonance ("NMR") spectroscopy and, for example, by methods described in U.S. Pat. No. 7,498,282. 13 C NMR analysis was measured by using the patent incorporated herein by reference.

[0039] The first layer comprises a polyolefin. The polyolefin may be polyethylene.

[0040] Polyethylene can have a thickness of 0.925 g / cm 3 Up to 0.950g / cm 3 All individual values ​​and subranges are included and disclosed. For example, polyethylene may have a density of 0.930 g / cm 3 Up to 0.945g / cm 3 density.

[0041] Polyethylene can have a melt index (I2) of 0.50 g / 10 min to 10.00 g / 10 min. All individual values ​​and subranges are included and disclosed. For example, polyethylene can have a melt index (I2) of from 0.50 g / 10 min, 1.00 g / 10 min, 2.00 g / 10 min, 3.00 g / 10 min, 4.00 g / 10 min, 5.00 g / 10 min to an upper limit of 9.00 g / 10 min, 8.00 g / 10 min, 7.00 g / 10 min, 6.00 g / 10 min, 5.00 g / 10 min, 4.00 g / 10 min, 3.00 g / 10 min or 2.00 g / 10 min.

[0042] Polyethylene polymers suitable for use in the present disclosure may be commercially available. Suitable commercial polyethylene polymers include, but are not limited to: AGILITY TM (For example, AGILITY TM 1000、AGILITY TM 1001 and AGILITY TM 1021) INNATE TM ST 50, ELITE TM 5940、ELITE TM 5960、DOW TM LDPE 6211 and DOW TM LDPE 7511, both purchased from The Dow Chemical Company.

[0043] Any conventional polymerization method can be used to produce ethylene acrylate copolymers and polyolefins. Such conventional polymerization methods include, but are not limited to, solution polymerization methods using one or more conventional reactors (e.g., loop reactors, isothermal reactors, stirred tank reactors, batch reactors, and / or any combination thereof in parallel or in series). Such conventional polymerization methods also include gas phase, solution, or slurry polymerization or any combination thereof using any type of reactor or reactor configuration known in the art.

[0044] The solution phase polymerization process may occur in one or more well-mixed reactors (such as one or more loop reactors) at a temperature in the range of 115°C to 250°C; for example, at a temperature in the range of 155°C to 225°C and at a pressure in the range of 300 psi to 1000 psi; for example, 400 psi to 750 psi. In a dual reactor, the temperature in the first reactor may be in the range of 115°C to 190°C (e.g., 115°C to 150°C), and the second reactor temperature may be in the range of 150°C to 200°C (e.g., 170°C to 195°C). In a single reactor, the temperature in the reactor may be in the range of 115°C to 250°C (e.g., 155°C to 225°C). The residence time in the solution phase polymerization process is typically in the range of 2 minutes to 30 minutes; for example, 10 minutes to 20 minutes. Ethylene, solvent, one or more catalyst systems, optionally one or more cocatalysts, optionally one or more impurity scavengers, and optionally one or more comonomers are continuously fed to the one or more reactors. Exemplary solvents include, but are not limited to, isoparaffins. For example, such solvents can be purchased from ExxonMobil Chemical Co., Houston, Texas, under the name ISOPAR E. The resulting mixture of the polymer composition and the solvent is then taken out from the reactor and the polymer composition is separated. The solvent is typically recovered via a solvent recovery unit (i.e., a heat exchanger and a vapor liquid separator drum) and subsequently recycled back into the polymerization system.

[0045] Polyolefins and ethylene acrylate copolymers can be produced via a solution polymerization process in a dual reactor system (e.g., a dual loop reactor system), wherein the polyolefin, polyethylene, or ethylene acrylate copolymer is polymerized in the presence of one or more catalyst systems. In addition, one or more cocatalysts may be present. Polyolefins and ethylene acrylate copolymers can be produced via a solution polymerization process in a single reactor system (e.g., a single loop reactor system), wherein the polyolefin or ethylene acrylate copolymer is polymerized in the presence of one or more catalyst systems.

[0046] An example of a suitable catalyst system comprises a pre-catalyst component comprising a metal-ligand complex of formula (I):

[0047]

[0048] In formula (I), M is a metal selected from titanium, zirconium or hafnium, the metal having a formal oxidation state of +2, +3 or +4; n is 0, 1, or 2; when n is 1, X is a monodentate ligand or a bidentate ligand; when n is 2, each X is a monodentate ligand and is the same or different; the metal-ligand complex is electrically neutral as a whole; each Z is independently selected from -O-, -S-, -N(R N )-, or-P(R P )-, where independently each R N and R P is (C1-C30)alkyl or (C1-C30)heteroalkyl; L is (C 1 -C 40 )alkylene or (C 1 -C 40 ) heteroalkylene, wherein (C 1 -C 40 ) the alkylene group has a moiety (to which L is bonded) comprising a 1-carbon atom to a 10-carbon atom connecting main chain connecting the two Z groups in formula (I), or (C 1 -C 40 ) heteroalkylene has a moiety comprising a 1-atom to 10-atom connecting backbone linking two Z groups in formula (I), wherein (C 1 -C 40 ) wherein each of the 1 to 10 atoms of the 1-atom to 10-atom connected main chain of the heteroalkylene group is independently a carbon atom or a heteroatom, wherein each heteroatom is independently O, S, S(O), S(O) 2 、Si(R C ) 2 , Ge(R C ) 2 , P(R C ) or N(R C ), where each R C Independently (C 1 -C 30 ) alkyl or (C 1 -C 30 ) heteroalkyl; R 1 and R 8 Independently selected from the group consisting of: -H, (C 1 -C 40 ) alkyl, (C 1 -C 40 ) heteroalkyl, -Si(R C ) 3 , -Ge(R C ) 3 、-P(R P ) 2 、-N(R N ) 2 、-ORC 、-SR C 、-NO 2 、-CN、-CF 3 , R C S(O)-、R C S(O) 2 -、(R C ) 2 C=N-、R C C(O)O-、R C OC(O)-、R C C(O)N(R N )-、(R N ) 2 NC(O)-, halogen and a group of formula (II), formula (III) or formula (IV):

[0049]

[0050] In formula (II), (III) and (IV), R 31-35 , R 41-48 or R 51-59 Each of which is independently selected from (C 1 -C 40 ) alkyl, (C 1 -C 40 ) heteroalkyl, -Si(R C ) 3 , -Ge(R C ) 3 、-P(R P ) 2 、-N(R N ) 2 、-N=CHR C 、-OR C 、-SR C 、-NO 2 、-CN、-CF 3 , R C S(O)-、R C S(O) 2 -、(R C ) 2 C=N-、R C C(O)O-、R C OC(O)-、R C C(O)N(R N )-、(R N ) 2 NC(O)-, halogen or -H, provided that R 1 or R 8 At least one of them is a group having formula (II), formula (III) or formula (IV), wherein RC , R N and R P As defined above.

[0051] In formula (I), R 2-4 , R 5-7 and R 9-16 Each of which is independently selected from (C 1 -C 40 ) alkyl, (C 1 -C 40 ) heteroalkyl, -Si(R C ) 3 , -Ge(R C ) 3 、-P(R P ) 2 、-N(R N ) 2 、-N=CHR C 、-OR C 、-SR C 、-NO 2 、-CN、-CF 3 , R C S(O)-、R C S(O) 2 -、(R C ) 2 C=N-、R C C(O)O-、R C OC(O)-、R C C(O)N(R N )-、(R C ) 2 NC(O)-, halogen and -H, where R C , R N and R P As defined above.

[0052] Catalyst systems comprising the metal-ligand complex of formula (I) may be rendered catalytically active by any technique known in the art for activating metal-based catalysts for olefin polymerization reactions. For example, the metal-ligand complex of formula (I) may be rendered catalytically active by contacting the complex with an activating cocatalyst or combining the complex with an activating cocatalyst. Activating cocatalysts suitable for use herein include alkylaluminums; polymeric or oligomeric aluminoxanes (also referred to as aluminoxanes); neutral Lewis acids; and non-polymeric, non-coordinating, ion-forming compounds (including the use of such compounds under oxidizing conditions). A suitable activation technique is bulk electrolysis. Combinations of one or more of the foregoing activating cocatalysts and techniques are also contemplated. The term "alkylaluminum" means a monoalkylaluminum dihydride or monoalkylaluminum dihalide, a dialkylaluminum hydride or dialkylaluminum halide, or a trialkylaluminum. Examples of polymeric or oligomeric aluminoxanes include methylaluminoxane, methylaluminoxane modified with triisobutylaluminum, and isobutylaluminoxane.

[0053] Lewis acid activators (cocatalysts) include those containing 1 to 3 (C 1 -C 20 ) hydrocarbyl substituent. Examples of Group 13 metal compounds are tris(C 1 -C 20 ) alkyl) substituted aluminum or tri((C 1 -C 20 ) alkyl)-boron compounds; tri(alkyl)-substituted aluminum, tri((C 1 -C 20 )alkyl)-boron compounds; tri((C 1 -C 10 )alkyl)aluminum, tri((C 6 -C 18 ) aryl) boron compounds; and their halogenated (including perhalogenated) derivatives. In another example, the Group 13 metal compound is tri(fluoro-substituted phenyl) borane, tri(pentafluorophenyl) borane. The activating cocatalyst may be tri((C 1 -C 20 ) alkyl borate (e.g. trityl tetrafluoroborate) or tris((C 1 -C 20 )alkyl)tetra((C 1 -C 20 ) alkyl) ammonium borane (e.g., bis(octadecyl)methyl tetra(pentafluorophenyl)ammonium borane). As used herein, the term "ammonium" means a nitrogen cation, which is ((C 1 -C 20 )alkyl) 4 N + 、((C 1 -C 20 )alkyl) 3N(H) + 、((C 1 -C 20 )alkyl) 2 N(H) 2 + , (C 1 -C 20 )Hydrocarbon N(H) 3 + or N(H) 4 + , where there are two or more (C 1 -C 20 ) hydrocarbon groups, they may be the same or different.

[0054] The combination of neutral Lewis acid activators (cocatalysts) includes tri((C 1 *C 4 )alkyl)aluminum and tri((C 6 *C 18 The present invention also provides a mixture of a combination of (a) (phenyl) boron compounds (especially tris (pentafluorophenyl) borane) or a combination of such a neutral Lewis acid mixture with a polymeric or oligomeric aluminoxane, and a single neutral Lewis acid, especially a combination of tris (pentafluorophenyl) borane with a polymeric or oligomeric aluminoxane. The ratio of the number of moles of (metal-ligand complex): (tris (pentafluoro-phenyl borane): (aluminoxane) [e.g., (Group 4 metal-ligand complex): (tris (pentafluoro-phenyl borane): (aluminoxane)] is 1:1:1 to 1:10:30, or 1:1:1.5 to 1:5:10.

[0055] The metal-ligand complex catalyst system comprising formula (I) can be activated by combining with one or more cocatalysts (e.g., cation-forming cocatalysts, strong Lewis acids, or combinations thereof) to form an active catalyst composition. Suitable activating cocatalysts include polymeric or oligomeric aluminoxanes (especially methylaluminoxane) and inert, compatible, non-coordinating, ion-forming compounds. Exemplary suitable cocatalysts include, but are not limited to, modified methylaluminoxane (MMAO), bis(hydrogenated tallow alkyl)methyltetrakis(pentafluorophenyl)boric acid (1 - )amines, and combinations thereof.

[0056] One or more of the aforementioned activating co-catalysts may be used in combination with each other. A preferred combination is three (C 1 -C 4 )alkyl)aluminum, tri((C 1 -C 4)alkyl)borane or ammonium borate and a mixture of oligomeric or polymeric aluminoxane compounds. The ratio of the total moles of one or more metal-ligand complexes of formula (I) to the total moles of one or more activating cocatalysts in the activating cocatalyst is 1:10,000 to 100:1. The ratio may be at least 1:5000, or at least 1:1000; and may not exceed 10:1 or not exceed 1:1. When aluminoxane is used alone as an activating cocatalyst, the moles of aluminoxane employed may preferably be at least 100 times the moles of the metal-ligand complex of formula (I). When tris(pentafluorophenyl)borane is used alone as an activating cocatalyst, the moles of tris(pentafluorophenyl)borane employed to the total moles of one or more metal-ligand complexes of formula (I) may be 0.5:1 to 10:1, 1:1 to 6:1, or 1:1 to 5:1. The remaining activating co-catalyst is generally employed in a molar amount approximately equal to the total molar amount of the one or more metal-ligand complexes of formula (I).

[0057] Film, composite and product production

[0058] The disclosed films can be prepared by any method known in the art. These include, but are not limited to, cast longitudinal orientation, in which a polymer is extruded through a flat die to produce a flat solid film, and then uniaxially oriented in the longitudinal direction at an elevated temperature (such as 20°C to 50°C below the melting point of the polymer). The films described herein can also be prepared using blown longitudinal orientation, whereby a polymer is extruded through an annular die and a tube of film is produced, which can be cut to produce a solid flat film, and then uniaxially oriented in the longitudinal direction at an elevated temperature (such as 20°C to 50°C below the melting point of the polymer).

[0059] A typical extrusion device consists of a hopper upstream of the process and a die downstream of the process. The hopper feeds the polymer into the barrel of the extruder containing the screw. The screw can usually be divided into 3 sections, namely the feed section, the compression section and the metering section. Along the barrel of the extruder, there will be multiple heating zones from back to front. The screw conveys the polymer forward while simultaneously melting and compressing the polymer melt in the barrel of the extruder. The compression ratio of the screw is usually 2.5 to 3.5. For this type of extruder device, the ratio of the length to the diameter of the barrel is 16:1 to 30:1. The extrusion process can be carried out at a temperature in the range of 160 to 270 degrees Celsius. At the end of the barrel, at the downstream end between the screw and the die, is a diverter plate and filter screen combination.

[0060] Titanium dioxide and calcium carbonate may be added during film production as is known in the art.

[0061] Composite materials including films as described herein laminated to nonwovens are also disclosed.Female hygiene products including the disclosed composite materials are disclosed.Female hygiene products including films as described herein are disclosed.A female hygiene product including a top sheet is disclosed, wherein the top sheet includes the above-mentioned film.For example, the female hygiene product disclosed herein may include the film disclosed herein and also include a nonwoven. "Nonwoven" includes nonwoven fiber webs, nonwoven fabrics, and any nonwoven structure in which individual fibers or threads are interlaced, but not in a regular or repeated manner.The nonwovens described herein can be formed by a variety of methods, such as air-laid, melt-blown, spunbond, and carding, including bonded carded webs.

[0062] Test Method

[0063] Softness evaluation

[0064] The drapability of the films was evaluated using the Hand Tester test according to the WSP 90.3 standard. The coefficient of friction was measured according to ASTM 1894 as a measure of the cottony touch of the hand.

[0065] Mechanical performance evaluation

[0066] Tensile strength and elongation were measured according to ASTM D882. Elmendorf tear was measured according to ASTM D1922, and puncture was measured according to ASTM D5748.

[0067] luster :

[0068] Gloss is measured according to ASTM D2457 at 45° and a magnified photograph of reflected light is taken at the film surface.

[0069] density

[0070] Density is measured according to ASTM D792 and is expressed in grams / cm 3 (g / cm 3 )express.

[0071] Melt Index

[0072] Melt index (I2) is measured according to ASTM D-1238 at 190°C and 2.16 kg. Values ​​are reported in g / 10 min; this corresponds to the number of grams eluted per 10 minutes.

[0073] Example

[0074] The materials used for both the Inventive Examples and the Comparative Examples are listed below in Table 1. All of the following resins are commercially available from The Dow Chemical Company.

[0075] Table 1: Materials

[0076] Material <![CDATA[Density (g / cm 3 )]]> Melt index (I2) (g / 10min) <![CDATA[AGILITY TM 6047 Performance LDPE 0.947 6.00 <![CDATA[ELITE TM 5230 G reinforced polyethylene resin]]> 0.916 4.00 <![CDATA[INFUSE TM 9507 Olefin Block Copolymer]]> 0.866 5.00 <![CDATA[AGILITY TM EC 7000 Performance LDPE]]> 0.918 3.90 <![CDATA[ELVAX TM 260 Ethylene-vinyl acetate copolymer]]> 0.955 2.00 <![CDATA[AFFINITY TM VP 8770G1 Polyolefin plastomer]]> 0.887 1.00 <![CDATA[ELVALOY TM AC1330 Acrylate Copolymer]]> 0.950 3.00 <![CDATA[White pigment (masterbatch 70% TiO 2 )]]> <![CDATA[Calcium carbonate (masterbatch 70% CaCO 3 )]]>

[0077] Coextrusion of multilayer films is well known in the art and includes coextrusion blown films and cast films, such as described in U.S. Patent Nos. 3,479,425, 3,797,987, 3,959,431 and 4,406,547. Multilayer films can be produced by coextruding two or more melt streams through a die so as to produce a layered structure when allowed to cool. The present film and comparative film were produced in a Collin Cast pilot production line with a width of 600 mm and 3 coextrusion layers in the following configuration: ABC, where A is the bottom layer and C is the top layer. The die gap was 0.7 mm, the extrusion temperature was set to 270°C, and the die temperature was set to 280°C. The production rate was set to 10 kg / hour, where layer A corresponded to 35% of the total thickness, layer B corresponded to 45% of the total thickness, and layer C corresponded to 20% of the total thickness. The line speed was set to 11.88 m / min to produce a film with a final thickness of 25 microns or about 23 gsm (grams / square meter). Table 2 below shows the formulation of the first / top layer, layer C. The percentages in Table 2 are weight percentages (wt.%) based on the total weight of the first layer. In addition to the materials in Table 2, the first layer of the reference example, along with the inventive and comparative examples, also contained 15 wt.% of white pigment.

[0078] Table 2: Experimental and comparative formulations for first layer with 15% white pigment

[0079]

[0080]

[0081] Each of the above samples is a three-layer film, where the first layer is the outer / top layer. This layer contains 20% of each structure. The other outer / bottom layer contains 35% of each structure and contains 60% AGILITY TM 6047 and 40% AGILITY TM EC7000. The core / middle layer contains 45% of each structure and contains 50% of AGILITY TM 6047, 20% ELITE TM 5230G and 30% AGILITY TM EC 7000. The composition of the base and middle layers can vary depending on the end application and product requirements.

[0082] Table 3: Properties of Inventive Examples and Comparative Examples

[0083] refer to IE-1 IE-2 IE-3 CE-1 CE-2 CE-3 Drapability(gf)MD 5.7 2.8 2.7 3.2 3.3 3.8 3.5 Drapability (gf)CD 6.9 3.4 3.2 3.5 4.1 3.7 3.3 Average dynamic friction coefficient 0.33 1.63 1.35 1.20 2.37 1.23 1.27 Average static friction coefficient 0.35 1.49 1.24 1.18 1.58 1.11 1.13 Gloss at 45°(%) 46 24 16 16 40 44 40 Tensile strength at break (N / 5cm) MD 21.7 20.7 21.4 18.3 15.5 22.7 19.8 Tensile strength at break (N / 5cm)CD 16.3 18.1 18.7 14.3 16.4 21.1 19.2 Elongation at break (%) MD 524 544 620 559 465 636 550 Elongation at break (%)CD 707 766 748 704 772 801 778 Elmendorf Tear (gf) MD 26 122 69 57 79 102 72 Elmendorf Rip (gf) CD 326 325 316 352 322 346 322 <![CDATA[Average puncture resistance (J / cm 3 )]]> 1.54 1.61 0.93 1.14 2.39 2.28 1.46

[0084] from Figure 1 As can be seen from the graph, the drape of Inventive Examples 1, 2, and 3 (IE-1, IE-2, and IE-3) is twice that of the Reference Example and is consistently better than the Comparative Sample. Figure 2 As shown, the Inventive Examples have a higher coefficient of friction than the Reference Examples and compare favorably to all Comparative Examples except CE- 1. However, CE- 1 is undesirably rubbery and sticky. Figure 3 and Figure 4 A significant improvement in opacity is shown as evidenced by numerical measurements of gloss and magnified photographs of the film surface showing luminosity. Finally, a seven person human sensory panel observed greater softness and less noise generation when handling samples of IE-3 when compared to the reference examples in Table 2.

[0085] All of this is achieved without using lower density or lower crystallinity resins. Figures 5 to 7 As shown, this can also be achieved without sacrificing the mechanical properties of the membrane. Figure 5 As can be seen, the longitudinal tear strength in IE-1 and IE-2 is actually improved when compared to the reference example.

Claims

1. A feminine hygiene product comprising a film having at least a first layer and optionally a second layer, the first layer comprising at least 25 weight percent of an ethylene acrylate copolymer based on the total weight of the first layer and less than 75 weight percent of a polyolefin based on the total weight of the first layer.

2. The feminine hygiene article according to claim 1, wherein the ethylene acrylate copolymer is ethylene methyl acrylate copolymer, ethylene ethyl acrylate copolymer or ethylene n-butyl acrylate copolymer.

3. The feminine hygiene article according to claim 1 or 2, wherein the ethylene acrylate copolymer comprises at least 16 wt% acrylate, based on the total weight of the ethylene acrylate copolymer.

4. The feminine hygiene article of any one of the preceding claims, wherein the first layer further comprises a white pigment.

5. The feminine hygiene article according to any one of the preceding claims, wherein the polyolefin is a polyolefin having a g / cm 3 Up to 0.950g / cm 3 A polyethylene having a density of and a melt index (I2) of 0.50 g / 10 min to 10.00 g / 10 min.

6. The feminine hygiene article according to any one of the preceding claims, wherein the first layer further comprises calcium carbonate.

7. The feminine hygiene article of any one of the preceding claims, wherein the first layer comprises at least 5 wt% white pigment, based on the total weight of the first layer.

8. The feminine hygiene article of any one of the preceding claims, wherein the film further comprises a second layer and a third layer, the second layer and the third layer each respectively comprising a polyethylene composition.

9. The feminine hygiene article of any one of the preceding claims, wherein the first layer has a gloss of less than 40%.

10. The feminine hygiene article of any one of the preceding claims, wherein the film has a drapability of less than 10.0 gf in both the machine and cross directions.

11. The feminine hygiene article of any of the preceding claims, further comprising a nonwoven.

12. A feminine hygiene article comprising a pad having a topsheet, wherein the topsheet comprises the film of claim 1.

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