WO2022112946A1

WO2022112946A1 - Article including microporous film and colored adhesive and process of making the same

Info

Publication number: WO2022112946A1
Application number: PCT/IB2021/060878
Authority: WO
Inventors: Neelakandan Chandrasekaran; Lori-Ann S. Prioleau
Original assignee: 3M Innovative Properties Company
Priority date: 2020-11-28
Filing date: 2021-11-23
Publication date: 2022-06-02

Abstract

The article includes a microporous thermoplastic film having first and second major surfaces and having an opaque, microporous region and a see-through region of lower porosity having a pre-determined shape. The article further includes a first adhesive having a first color disposed on the second major surface of the microporous thermoplastic film, wherein a portion of the first adhesive is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film. The article may include multiple adhesives with multiple colors. A method of making the article is also described.

Description

ARTICLE INCLUDING MICROPOROUS FILM AND COLORED ADHESIVE AND PROCESS OF MAKING THE

SAME

BACKGROUND

Film articles having printed and/or colored regions are useful for several different applications. For example, colored duct tape and washi tape have become popular for decorating and craft projects. A variety of different personal hygiene articles (e.g., absorbent articles such as diapers, adult incontinence products, and sanitary napkins) that include different printed and/or colored regions are available in the market. Printing or coloring on these and other articles can be attractive to the consumer and help the consumer differentiate between different brands. Some manufacturers of absorbent articles print with multi-colored graphics that are a signature of their brand. Others may use monochromatic printing on the articles.

Multilayer constructions including a colored film layer and a layer having an opaque region and a see-through region, which are useful in personal hygiene articles and printable films, are disclosed in U.S. Pat. Nos. 5,897,541 (Uitenbroek et ah), 8,968,863 (Brown et ah), and 10,376,420 (Chandrasekaran et ak). Other multilayer constructions including a colored film layer and a layer having an opaque region and a see-through region, which are useful in mechanical fasteners, personal hygiene articles, and tapes, are disclosed in U.S. Pat. No. 10,709,619 (Chandrasekaran et ak), U.S. Pat. Appk Pub. No. 2016/01288876 (Chandrasekaran et ak), and in Int. Pat. Appk Pub. No. WO 2020/142433 (Chandrasekaran et ak).

SUMMARY

The present disclosure can be useful, for example, for providing visual images on products without the need for the printing of inks or the use of colored films. The article of the present disclosure includes an opaque, microporous region and a see-through region of lower porosity. The contrast between opaque, microporous regions and see-through region of lower porosity in the article of the present disclosure typically and advantageously provides a durable image that is resistant to fading over time, which is advantageous over inks and color-changing chemicals. Furthermore, since the articles include a microporous thermoplastic film, they can block the transmission of light (e.g., by scattering), allowing them to be detected in inspection systems that rely upon shining a light onto a substrate and detecting the amount of light received from the area of the irradiated substrate. Thus, the articles of the present disclosure are useful for facilitating the inspection process of certain manufactured products. The opaque, microporous region and see-through region have predetermined (in other words, designed) shapes. Advantageously, the regions can be in the form of a wide variety of patterns, numbers, pictures, symbols, alphabetical letters, bar codes, or combinations thereof that can be selected to be decorative or distinguishing. The region can also be in the form of a company name, brand name, or logo that may be readily identified by a customer.

While multilayer articles including a colored film layer and a layer having an opaque region and a see-through region have been described previously, the present disclosure provides an article that includes a colored adhesive instead of a colored film layer. The article of the present disclosure has several advantages over multilayer constructions including colored films. Putting a colored film through a film line may require subsequent purging because of the potential for color transfer. This increase in process steps leads to increased cost and decreased productivity. Coating or spraying with adhesive is within the capabilities of most film manufacturers and would not require a capital investment. Since colorless adhesives are often used to form multilayer film articles, and bond such articles to substrates, the use of colored adhesive can reduce the number of components in an article, thereby reducing cost. The colored adhesive also would provide flexibility for altering products. For example, for a given single pattern of see-through regions of lower porosity in the microporous film disclosed herein, multiple colors in the product can be achieved simply by changing the color of the adhesive. Thus, the article of the present disclosure can be more readily customized than a multilayer film article to meet the requirements of a particular product.

In one aspect, the present disclosure provides an article that includes a microporous thermoplastic film having first and second major surfaces, the microporous thermoplastic film comprising an opaque, microporous region and a see-through region of lower porosity having a pre-determined shape. The article further includes a first adhesive having a first color disposed on the second major surface of the microporous thermoplastic film, and a portion of the first adhesive is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

In some embodiments, the article further includes a substrate, and the first adhesive adheres the microporous thermoplastic film to the substrate.

In another aspect, the present disclosure provides a process of making the article. The process can include at least one of spraying, printing, or coating the first adhesive onto the second major surface of the microporous thermoplastic film. The process can additionally or alternatively include at least one of spraying, printing, or coating the first adhesive onto the substrate and adhering the microporous thermoplastic film to the substrate.

In this application, terms such as "a", "an" and "the" are not intended to refer to only a singular entity but include the general class of which a specific example may be used for illustration. The terms "a", "an", and "the" are used interchangeably with the term "at least one". The phrases "at least one of' and "comprises at least one of' followed by a list refers to any one of the items in the list and any combination of two or more items in the list. All numerical ranges are inclusive of their endpoints and non-integral values between the endpoints unless otherwise stated. The terms "first" and "second" are used in this disclosure in their relative sense only. It will be understood that, unless otherwise noted, those terms are used merely as a matter of convenience in the description of one or more of the embodiments.

The term “microporous” refers to having multiple pores that have an average dimension (in some cases, diameter) of up to 10 micrometers. At least some of the multiple pores should have a dimension on the order of or larger than the wavelength of visible light. For example, at least some of the pores should have a dimension (in some cases, diameter) of at least 400 nanometers. Pore size is measured by measuring bubble point according to ASTM F-316-80. The pores may be open cell pores or closed cell pores. In some embodiments, the pores are closed cell pores.

The term “see-through” refers to either transparent (that is, allowing passage of light and permitting a clear view of objects beyond) or translucent (that is, allowing passage of light and not permitting a clear view of objects beyond).

Regions of “lower porosity” refer to regions having fewer pores per unit volume.

The term “predetermined” refers to being establish or determined when the see-through regions of lower porosity are made. A “predetermined” shape does not refer to a change in the see-through regions that results from the use of the article of the present disclosure for its intended purpose.

If the see-through region is said to be “within” the opaque, microporous region, it means that the opaque, microporous region may border the see-through region on at least two sides or more. In some embodiments, the opaque, microporous region surrounds the see-through region. Generally, the see- through region is not found only at the edge of the microporous film.

The thickness of a film should be understood to be its smallest dimension. It is generally referred to as the “z” dimension and refers to the distance between the first and second major surfaces of the film.

The term "upstanding" with regard to mechanical fastening elements refers to posts that protrude from the thermoplastic backing and includes posts that stand perpendicular to the backing and posts that are at an angle to the backing other than 90 degrees.

The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. It is to be understood, therefore, that the drawings and following description are for illustration purposes only and should not be read in a manner that would unduly limit the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an embodiment of an article of the present disclosure; FIG. 2 is a perspective view of an embodiment of a personal hygiene article incorporating an embodiment of an article of the present disclosure;

FIG. 2A is an embodiment of an exploded cross-sectional side view taken along line 2A-2A of

FIG. 2;

FIG. 2B is an expanded view of the indicated area of FIG. 2;

FIG. 3 is a perspective view of an embodiment of personal hygiene article incorporating an article of the present disclosure, in which the article is useful as a disposal tape;

FIG. 3 A is an expanded view of the indicated area in FIG. 3;

FIG. 3B is a perspective view of the personal hygiene article shown in FIG. 3 rolled up and ready for disposal;

FIG. 4 is a side, cross-section view of another embodiment of the article of the present disclosure in which the article is a roll of tape; and

FIG. 5 illustrates another embodiment of the article of the present disclosure and a method for making the article.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of an article of the present disclosure. Article 100 includes a microporous thermoplastic fdm 101 that has an opaque, microporous region 112 and see-through regions 114 of lower porosity. The see-through regions 114 typically correspond to regions of the microporous thermoplastic fdm 101 having a smaller “z” dimension (that is, lower thickness) in comparison to the opaque, microporous regions 112. The microporous thermoplastic fdm has a first major surface 101a and second major surface 101b. The article 100 further includes a first adhesive 102 disposed on the second major surface 101b of the microporous thermoplastic fdm 101. The first adhesive 102 has a first color.

In some embodiments, the first color is other than white. The first adhesive may be opaque or transparent. A portion of the first adhesive 102 is visible through the see-through regions 114 of lower porosity when viewed from the first major surface 101a of the microporous thermoplastic fdm 101. In some embodiments, including the embodiment illustrated in FIG. 1, the article 100 further includes a second adhesive 104 disposed on the second major surface 101b of the microporous thermoplastic fdm 101. The second adhesive 104 has a second color other than the first color. In some embodiments, the second color is other than white. The second adhesive may be opaque or transparent. In the illustrated embodiment, portions of both the first adhesive 102 and the second adhesive 104 are visible through the see-through regions 114 of lower porosity when viewed from the first major surface 101a of the microporous thermoplastic fdm 101.

The size of any individual see-through region of lower porosity in the article according to the present disclosure may be at least 0.3 mm², 0.4 mm², 0.5 mm², or 0.7 mm². Generally, if the color contrast between the microporous thermoplastic fdm and the first adhesive having the first color (in some embodiments, and the second adhesive having the second color) is relatively large, smaller individual see- through regions (e.g., 0.3 mm² to 0.6 mm²) may be easily visible to the naked eye. However, if the color contrast between the microporous thermoplastic fdm and the first adhesive having the first color (in some embodiments, and the second adhesive having the second color) is relatively small, it may be desirable to have larger individual see-through regions of lower porosity (e.g., larger than 0.6 mm²).

In some embodiments, including the embodiment illustrated in FIG. 1, the article 100 of the present disclosure further comprises a substrate 103, and the first adhesive 102 adheres the microporous thermoplastic film 101 to the substrate 103. In the illustrated embodiment, the first adhesive 102 and the second adhesive 104 adhere the microporous thermoplastic film 101 to the substrate 103.

Various methods are useful for making the microporous thermoplastic film useful in the article of the present disclosure. In some embodiments, the porosity in the microporous thermoplastic film, results from beta-nucleation. Thermoplastics (e.g., semi-crystalline polyolefins) can have more than one kind of crystal structure. For example, isotactic polypropylene is known to crystallize into at least three different forms: alpha (monoclinic), beta (pseudohexangonal), and gamma (triclinic) forms. In melt-crystallized material the predominant form is the alpha or monoclinic form. The beta form generally occurs at levels of only a few percent unless certain heterogeneous nuclei are present, or the crystallization has occurred in a temperature gradient or in the presence of shearing forces. The heterogeneous nuclei are typically known as beta-nucleating agents, which act as foreign bodies in a crystallizable polymer melt. When the polymer cools below its crystallization temperature (e.g., a temperature in a range from 60 °C to 120 °C or 90 °C to 120 °C), the loose coiled polymer chains orient themselves around the beta-nucleating agent to form beta-phase regions. The beta form of polypropylene is a meta-stable form, which can be converted to the more stable alpha form by thermal treatment and/or applying stress. Micropores can be formed in various amounts when the beta-form of polypropylene is stretched under certain conditions; see, e.g., Chu et al., “Microvoid formation process during the plastic deformation of b-form polypropylene”, Polymer, Vol. 35, No. 16, pp. 3442-3448, 1994, and Chu et al., “Crystal transformation and micropore formation during uniaxial drawing of b-form polypropylene film”, Polymer, Vol. 36, No. 13, pp. 2523-2530, 1995. Pore sizes achieved from this method can range from about 0.05 micrometer to about 1 micrometer, in some embodiments, about 0.1 micrometer to about 0.5 micrometer.

Generally, when the porosity in the microporous thermoplastic film is generated from a beta- nucleating agent, the film comprises a semi-crystalline polyolefin. Various polyolefins may be useful. Typically, the semi -crystalline polyolefin comprises polypropylene. It should be understood that a semi crystalline polyolefin comprising polypropylene may be a polypropylene homopolymer or a copolymer containing propylene repeating units. The copolymer may be a copolymer of propylene and at least one other olefin (e.g., ethylene or an alpha-olefin having from 4 to 12 or 4 to 8 carbon atoms). Copolymers of ethylene, propylene and/or butylene may be useful. In some embodiments, the copolymer contains up to 90, 80, 70, 60, or 50 percent by weight of polypropylene. In some embodiments, the copolymer contains up to 50, 40, 30, 20, or 10 percent by weight of at least one of polyethylene or an alpha-olefin. The semi- crystalline polyolefin may also be part of a blend of thermoplastic polymers that includes polypropylene. Suitable thermoplastic polymers for such blends include crystallizable polymers that are typically melt processable under conventional processing conditions. That is, on heating, they will typically soften and/or melt to permit processing in conventional equipment, such as an extruder, to form a sheet. Crystallizable polymers, upon cooling their melt under controlled conditions, spontaneously form geometrically regular and ordered chemical structures. Examples of suitable crystallizable thermoplastic polymers include addition polymers, such as polyolefins. Useful polyolefins include polymers of ethylene (e.g., high density polyethylene, low density polyethylene, or linear low density polyethylene), an alpha-olefin (e.g., 1-butene, 1-hexene, or 1-octene), styrene, and copolymers of two or more such olefins. The semi -crystalline polyolefin may comprise mixtures of stereo-isomers of such polymers, e.g., mixtures of isotactic polypropylene and atactic polypropylene or of isotactic polystyrene and atactic polystyrene. In some embodiments, the semi-crystalline polyolefin blend contains up to 90, 80, 70, 60, or 50 percent by weight of polypropylene. In some embodiments, the blend contains up to 50, 40, 30, 20, or 10 percent by weight of at least one of polyethylene or an alpha-olefin.

In some embodiments, the microporous thermoplastic film is made from a polymeric composition comprising a semi -crystalline polyolefin and having a melt flow rate in a range from 0.1 to 10 decigrams per minute, for example, 0.25 to 2.5 decigrams per minute.

When the porosity in the microporous thermoplastic film is generated from a beta-nucleating agent, the beta-nucleating agent may be any inorganic or organic nucleating agent that can produce beta- spherulites in a melt-formed sheet comprising polyolefin. Useful beta-nucleating agents include gamma quinacridone, an aluminum salt of quinizarin sulphonic acid, dihydroquinoacridin-dione and quinacridin- tetrone, triphenenol ditriazine, calcium silicate, dicarboxylic acids (e.g., suberic, pimelic, ortho-phthalic, isophthalic, and terephthalic acid), sodium salts of these dicarboxylic acids, salts of these dicarboxylic acids and the metals of Group IIA of the periodic table (e.g., calcium, magnesium, or barium), delta- quinacridone, diamides of adipic or suberic acids, different types of indigosol and cibantine organic pigments, quinacridone quinone, N',N'-dicyclohexil-2, 6-naphthalene dicarboxamide (available, for example, under the trade designation “NJ-Star NU-100” from New Japan Chemical Co. Utd.), anthraquinone red, and bis-azo yellow pigments. The properties of the extruded film are dependent on the selection of the beta nucleating agent and the concentration of the beta-nucleating agent. In some embodiments, the beta-nucleating agent is selected from the group consisting of gamma-quinacridone, a calcium salt of suberic acid, a calcium salt of pimelic acid and calcium and barium salts of polycarboxylic acids. In some embodiments, the beta-nucleating agent is quinacridone colorant Permanent Red E3B, which is also referred to as Q-dye. In some embodiments, the beta-nucleating agent is formed by mixing an organic dicarboxylic acid (e.g., pimelic acid, azelaic acid, o-phthalic acid, terephthalic acid, and isophthalic acid) and an oxide, hydroxide, or acid salt of a Group II metal (e.g., magnesium, calcium, strontium, and barium). So-called two component initiators include calcium carbonate combined with any of the organic dicarboxylic acids listed above and calcium stearate combined with pimelic acid. In some embodiments, the beta-nucleating agent is aromatic tri-carboxamide as described in U.S. Pat. No. 7,423,088 (Mader et al.).

The beta-nucleating agent serves the important functions of inducing crystallization of the polymer from the molten state and enhancing the initiation of polymer crystallization sites so as to speed up the crystallization of the polymer. Thus, the nucleating agent may be a solid at the crystallization temperature of the polymer. Because the nucleating agent increases the rate of crystallization of the polymer, the size of the resultant polymer particles, or spherulites, is reduced.

A convenient way of incorporating beta-nucleating agents into a thermoplastic (e.g., semi crystalline polyolefin) useful for making a microporous thermoplastic film disclosed herein is through the use of a concentrate. A concentrate is typically a highly loaded, pelletized resin (e.g., polypropylene) containing a higher concentration of nucleating agent than is desired in the final microporous film. The nucleating agent is present in the concentrate in a range of 0.01% to 2.0% by weight (100 to 20,000 ppm), in some embodiments in a range of 0.02% to 1% by weight (200 to 10,000 ppm). Typical concentrates are blended with non-nucleated polyolefin, for example, in the range of 0.5% to 50% (in some embodiments, in the range of 1% to 10%) by weight of the total polyolefin content of the microporous thermoplastic film. The concentration range of the beta-nucleating agent in the final microporous thermoplastic film may be 0.0001% to 1% by weight (1 ppm to 10,000 ppm), in some embodiments, 0.0002% to 0.1% by weight (2 ppm to 1000 ppm). A concentrate can also contain other additives such as stabilizers, pigments, and processing agents.

The level of beta-spherulites in the semi -crystalline polyolefin can be determined, for example, using X-ray crystallography and Differential Scanning Calorimetry (DSC). By DSC, melting points and heats of fusion of both the alpha phase and the beta phase can be determined in a microporous film useful for practicing the present disclosure. For semi-crystalline polypropylene, the melting point of the beta phase is lower than the melting point of the alpha phase (e.g., by about 10 to 15 °C). The ratio of the heat of fusion of the beta phase to the total heat of fusion provides a percentage of the beta-spherulites in a sample. The level of beta-spherulites can be at least 10, 20, 25, 30, 40, or 50 percent, based on the total amount of alpha and beta phase crystals in the film. These levels of beta-spherulites may be found in the film before it is stretched.

In some embodiments, the microporous thermoplastic film useful for practicing the present disclosure in any of its embodiments is formed using a thermally induced phase separation (TIPS) method. This method of making the microporous thermoplastic film typically includes melt blending a crystallizable thermoplastic polymer and a diluent to form a melt mixture. The melt mixture is then formed into a film and cooled to a temperature at which the polymer crystallizes, and phase separation occurs between the polymer and diluent, forming voids. In this manner a film is formed that comprises an aggregate of crystallized polymer in the diluent compound. The voided film has some degree of opacity.

In some embodiments, following formation of the crystallized polymer, the porosity of the material is increased by at least one of stretching the film in at least one direction or removing at least some of the diluent. This step results in separation of adjacent particles of polymer from one another to provide a network of interconnected micropores. This step also permanently attenuates the polymer to form fibrils, imparting strength and porosity to the film. The diluent can be removed from the material either before or after stretching. In some embodiments, the diluent is not removed. Pore sizes achieved from this method can range from about 0.2 micron to about 5 microns.

When the microporous thermoplastic film useful for practicing the present disclosure is made from a TIPS process, the film can comprise any of the semi-crystalline polyolefins described above in connection with films made by beta-nucleation. In addition, other thermoplastic polymers that may be useful alone or in combination include high and low density polyethylene, polyfvinylidine fluoride), polyfmethyl pentene) (e.g., poly(4-methylpentene), poly(lactic acid), poly(hydroxybutyrate), poly(ethylene-chlorotrifluoroethylene), polyfvinyl fluoride), polyvinyl chloride, polyethylene terephthalate), polyfbutylene terephthalate), ethylene -vinyl alcohol copolymers, ethylene-vinyl acetate copolymers, polybuyltene, polyurethanes, and polyamides (e.g., nylon-6 or nylon-66). Useful diluents for providing the microporous thermoplastic film include mineral oil, mineral spirits, dioctylphthalate, liquid paraffins, paraffin wax, glycerin, petroleum jelly, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, soft carbowax, and combinations thereof. The quantity of diluent is typically in a range from about 20 parts to 70 parts, 30 parts to 70 parts, or 50 parts to 65 parts by weight, based upon the total weight of the polymer and diluent.

Particulate cavitating agents are also useful for making microporous thermoplastic films useful for the article of the present disclosure. Such cavitating agents are incompatible or immiscible with the polymeric matrix material and form a dispersed phase within the polymeric core matrix material before extrusion and orientation of the film. When such a polymer substrate is subjected to uniaxial or biaxial stretching, a void or cavity forms around the distributed, dispersed-phase moieties, providing a film having a matrix filled with numerous cavities that provide an opaque appearance due to the scattering of light within the matrix and cavities. The microporous thermoplastic film can comprise any of the polymers described above in connection with TIPS films. The particulate cavitating agents may be inorganic or organic. Organic cavitating agents generally have a melting point that is higher than the melting point of the film matrix material. Useful organic cavitating agents include polyesters (e.g., polybutylene terephthalate or nylon such as nylon-6), polycarbonate, acrylic resins, and ethylene norbomene copolymers. Useful inorganic cavitating agents include talc, calcium carbonate, titanium dioxide, barium sulfate, glass beads, glass bubbles (that is, hollow glass spheres), ceramic beads, ceramic bubbles, and metal particulates. The particle size of cavitating agents is such that at least a majority by weight of the particles comprise an overall mean particle diameter, for example, of from about 0.1 micron to about 5 microns, in some embodiments, from about 0.2 micron to about 2 microns. (The term "overall" refers to size in three dimensions; the term "mean" is the average.) The cavitating agent may be present in the polymer matrix in an amount of from about 2 weight percent to about 40 weight percent, about 4 weight percent to about 30 weight percent, or about 4 weight percent to about 20 weight percent, based upon the total weight of the polymer and cavitating agent. While particulate cavitating agents may be useful for making some embodiments of the microporous thermoplastic film disclosed herein, generally microporous films made with such cavitating agents provide see-through regions that are less transparent than when beta-nucleation or the TIPS process is used. Accordingly, in some embodiments, the microporous thermoplastic film comprises at least one of a beta-nucleating agent or a diluent. In some embodiments, the microporous thermoplastic film is free of a particulate cavitating agents or contains less than 2, 1.5, 1, 0.5, or 0.1 percent of such cavitating agents, based on the total weight of the film.

Additional ingredients may be included in the microporous thermoplastic film useful for practicing any of the embodiments of the present disclosure, depending on the desired application. For example, surfactants, antistatic agents, ultraviolet radiation absorbers, antioxidants, organic or inorganic colorants, stabilizers, flame retardants, fragrances, nucleating agents other than a beta-nucleating agent, and plasticizers may be included. Many of the beta-nucleating agents described above have a color.

Also, colorants may be added, for example, in the form of a color concentrate or a colored master batch.

In some embodiments, the microporous thermoplastic film is not colored, in other words, the opaque, microporous regions are white.

For the microporous thermoplastic films made by any of the methods described above, the film is typically stretched to form or enhance the microporous structure. Stretching the film can be carried out on a web biaxially or monoaxially. Biaxial stretching means stretching in two different directions in the plane of the backing. Typically, but not always, one direction is the machine direction or longitudinal direction "L", and the other, different direction is the cross direction or width direction "W". Biaxial stretching can be performed sequentially by stretching the thermoplastic film, for example, first in one of the longitudinal or width direction and subsequently in the other of the longitudinal or width direction. Biaxial stretching can also be performed essentially simultaneously in both directions. Monoaxial stretching refers to stretching in only one direction in the plane of the thermoplastic film. Typically, monoaxial stretching is performed in one of the "L" or "W" direction but other stretch directions are also possible.

Stretching may be carried out before or after the first adhesive and optionally second adhesive is disposed on the second major surface of the microporous thermoplastic film. In some embodiments, stretching is carried out before the first adhesive and optionally second adhesive is disposed on the second major surface of the microporous thermoplastic film.

In some embodiments, the stretching increases at least one of the film's length ("L") or width ("W") at least 1.2 times (in some embodiments, at least 1.5, 2, or 2.5 times). In some embodiments, the stretching increases both of the film's length ("L") and width ("W") at least 1.2 times (in some embodiments, at least 1.5, 2, or 2.5 times). In some embodiments, the stretching increases at least one of the film's length ("L") or width ("W") up to 5 times (in some embodiments, up to 2.5 times). In some embodiments, the stretching increases both of the film's length ("L") and width ("W") up to 5 times (in some embodiments, up to 2.5 times). In some embodiments, the stretching increases at least one of the film's length ("L") or width ("W") up to 10 times (in some embodiments, up to 20 times or more). In some embodiments, the stretching increases both of the film's length ("L") and width ("W") up to 10 times (in some embodiments, up to 20 times or more).

In general, when a thermoplastic film is monoaxially or biaxially stretched at a temperature below the melting point of the thermoplastic material, particularly at a temperature below the line drawing temperature of the film, the thermoplastic film may stretch non-uniformly, and a clear boundary is formed between stretched and unstretched parts. This phenomenon is referred to as necking or line drawing. However, substantially the entire thermoplastic film is stretched uniformly when it is stretched to a sufficiently high degree. The stretch ratio at which this occurs is referred to as the "natural stretch ratio" or "natural draw ratio." Stretching above the natural stretch ratio is understood to provide significantly more uniform properties or characteristics such as thickness, tensile strength, and modulus of elasticity. For any given thermoplastic film and stretch conditions, the natural stretch ratio is determined by factors such as the composition of the thermoplastic resin forming the thermoplastic film, the morphology of the formed thermoplastic film due to quenching conditions on the tool roll, for example, and temperature and rate of stretching. Furthermore, for biaxially stretched thermoplastic films, the natural stretch ratio in one direction will be affected by the stretch conditions, including final stretch ratio, in the other direction. Thus, there may be said to be a natural stretch ratio in one direction given a fixed stretch ratio in the other, or, alternatively, there may be said to be a pair of stretch ratios (one in the first direction and one in the second direction) which result in the natural stretch ratio. The term "stretch ratio" refers to ratio of a linear dimension of a given portion of the thermoplastic film after stretching to the linear dimension of the same portion before stretching. The natural stretch ratio of the most common crystalline form of polypropylene, the alpha form, has been reported to be about 6:1.

Stretching the thermoplastic film useful for practicing the present disclosure can be carried out in a variety of ways. When the thermoplastic film is a web of indefinite length, for example, monoaxial stretching in the machine direction can be performed by propelling the film over rolls of increasing speed. The term "machine direction" (MD) as used herein denotes the direction of a running, continuous web of the film. A versatile stretching method that allows for monoaxial, sequential biaxial, and simultaneous biaxial stretching of the thermoplastic film employs a flat film tenter apparatus. Such an apparatus grasps the thermoplastic web using a plurality of clips, grippers, or other film edge-grasping means along opposing edges of the web in such a way that monoaxial, sequential biaxial, or simultaneous biaxial stretching in the desired direction is obtained by propelling the grasping means at varying speeds along divergent rails. Increasing clip speed in the machine direction generally results in machine-direction stretching. Means such as diverging rails generally results in cross-direction stretching. The term "cross direction" (CD) as used herein denotes the direction which is essentially perpendicular to the machine direction. Monoaxial and biaxial stretching can be accomplished, for example, by the methods and apparatus disclosed in U.S. Pat. No. 7,897,078 (Petersen et al.) and the references cited therein. Flat film tenter stretching apparatuses are commercially available, for example, from Briickner Maschinenbau GmbH, Siegsdorf, Germany.

Stretching the thermoplastic film is typically performed at elevated temperatures, for example, up to 150 °C. Heating the film may allow it to be more flexible for stretching. Heating can be provided, for example, by IR irradiation, hot air treatment or by performing the stretching in a heat chamber. In embodiments of the microporous thermoplastic film having upstanding posts on its first major surface, heating is only applied to a second major surface of the film opposite the first major surface from which the upstanding posts project to minimize any damage to the upstanding posts that may result from heating. For example, in these embodiments, only rollers that are in contact with the second surface of the film are heated. In some embodiments, stretching the film is carried out at a temperature range from 50 °C to 130 °C.

In the article of the present disclosure, the microporous thermoplastic film may have a variety of thicknesses. For example, the initial thickness (i.e., before any stretching) of the thermoplastic film may be up to about 750, 500, 400, 250, or 150 micrometers, depending on the desired application. In some embodiments, the initial thickness of the film is at least about 50, 75, or 100 micrometers, depending on the desired application. In some embodiments, the initial thickness of the film is in a range from 50 to about 225 micrometers, from about 75 to about 200 micrometers, or from about 100 to about 150 micrometers. The film may have an essentially uniform cross-section, or, in the case of embodiments including upstanding posts, the film may have structure beyond what is provided by the upstanding posts, which may be imparted, for example, by at least one of the forming rolls described below.

In some embodiments, stretching a thermoplastic film described above in order to form or enhance microporosity provides an increase in opacity of at least 10, 15, 20, 25, or 30 percent. The increase in opacity may be, for example, up to 90, 85, 80, 75, 70, 65, 60, 55, or 50 percent. The initial opacity is affected, for example, by the thickness of the film. Stretching a film typically results in a decrease in thickness, which would typically lead to a decrease in opacity. However, stress whitening and micropore formation leads to an increase in opacity. For the purposes of the present disclosure, opacity can be measured using a spectrophotometer with the “L” value measured separately against a black background and against a white background, respectively. The opacity is calculated as (L measured against the black background/L measured against the white background) times 100. The “L” value is one of three standard parameters in the CIELAB color space scale established by the International Commission on Illumination. "L" is a brightness value, ranging from 0 (black) to 100 (highest intensity). A percentage change in opacity that results from stretching is calculated by [(opacity after stretching - opacity before stretching)/opacity before stretching] times 100.

In some embodiments, stretching a thermoplastic film described above in order to form or enhance microporosity provides a decrease in the grayscale value of the film of at least twenty percent. In some embodiments, stretching provides a decrease in a grayscale value of at least 25, 30, 40, or 50 percent. The decrease in grayscale value may be, for example, up to 90, 85, 80, 75, 70, 65, or 60 percent. For the purposes of this disclosure, the grayscale value is measured in transmission mode using, for example, an IMPACT A20 digital camera (PPT Vision, Bloomington, MN) equipped with a CMOS (complementary metal oxide semiconductor) image sensor and the IMPACT Software Suite on a numeric scale ranging from 0 (high opacity) to 255 (low opacity). A sample can be illuminated on one side with a 940 nm wavelength light source with a detection camera mounted on the other side of the sample. Stretching a film typically results in a decrease in thickness, which would typically lead to an increase in the grayscale value measured in transmission mode. However, stress whitening and micropore formation leads to decrease in transmission mode grayscale values. A percentage change in grayscale value that results from stretching the film is calculated by [(grayscale value after stretching - grayscale value before stretching)/ grayscale value before stretching] times 100. In some embodiments, the microporous thermoplastic film has a grayscale value of up to 40 (in some embodiments, up to 35, 30, 25, 20 or 15).

In some embodiments, the grayscale values for the microporous thermoplastic films are comparable or better than those achieved for polyolefin films of similar composition but incorporating conventional amounts of IR blocking agents such as titanium dioxide.

The opacity and grayscale measurement of the microporous thermoplastic film relate to its ability to transmit light. As used herein, the term "light" refers to electromagnetic radiation, whether visible to the unaided human eye or not. Ultraviolet light is light having a wavelength in a range from about 250 nanometers (nm) to 380 nm. Visible light is light having a wavelength in a range from 380 nanometers (nm) to 700 nm. Infrared light has a wavelength in a range from about 700 nm to 300 micrometers. After the thermoplastic film useful for practicing the present disclosure has been stretched, it has decreased transmission to ultraviolet, visible, and infrared light. The micropores in the stretched film tend to scatter light in the ultraviolet, visible, and infrared ranges. The opacity and grayscale values of the opaque regions of the microporous thermoplastic film can be at least 50, 60, 70, 80, or at least 90 percent higher than the see-through regions as measured using the test methods described above.

Referring again to FIG. 1, the see-through regions 114 of lower porosity may be made by several useful methods. For example, a nip made from two heated rolls in which at least one of the rolls has raised areas in the shape of the see-through regions 114 may be useful. The heat and pressure in the nip can collapse the microporous structure in the raised areas to form the see-through regions. The illustrated embodiment can be made if only one roll includes the raised areas, and the other roll has a smooth surface. However, if both rolls may have raised areas in the shape of the see-through regions 114.

Heat, pressure, or a combination thereof may be useful for providing the see-through regions of lower porosity. Typically, the see-through region is heated to the melting temperature of the thermoplastic in the microporous thermoplastic film. Melting the microporous thermoplastic film in the see-through region results in a permanent change in the structure of the film in the see-through region, which can be accompanied by some film shrinkage in that region. Heating can be carried out in a press or a heated nip having a raised image of the see-through region so that pressure accompanies the heating to collapse the microporous structure. Pressure alone may provide a temporary change in the microporous structure of the microporous film in some instances. When using a static press, it can be useful to use a rubber surface on the film side opposite the side that is exposed to the raised and heated image. The rubber surface can prevent two hard surfaces from forming a hole in the film while the see-through region is being made. In a nip, the pressure and gap can be adjusted as well as the line speed to prevent forming holes in the film.

Heating may also be carried out with hot air or with a directed radiation source such as a laser. A variety of different types of laser may be useful. For example, a carbon dioxide laser may be useful. An ultraviolet laser and diode laser may also be useful. Suitable wavelengths for the laser can be in a range from 200 nm to 11,000 nm. The laser wavelength and absorption properties of the microporous thermoplastic film can be selected to be matched or nearly matched so as to cause the heating of thermoplastic film. For a person skilled in the art, the suitable power for the laser, beam size on the film, and speed of the beam movement across the film can be adjusted to achieve the desired heating. This matching of laser and film can be advantageous, for example, when the microporous thermoplastic film is a layer with a multilayer construction. Heating with the laser can be adjusted to a location of the microporous thermoplastic film within the multilayer construction (e.g., multilayer film). The heating can be made in a pattern by directing the radiation across the surface to expose an area of material, or the radiation can be directed across the surface of a suitable mask so that a patterned area is exposed to the radiation. The microporous thermoplastic film may be positioned outside of the focal plane of the laser to adjust the level of heating.

For some applications such as heat seal films, recording media, and oil-absorbing cosmetic sheets, it has been shown that changing the microporous structure in a region of a microporous film can change the opacity in that region. See, for example, GB 2323327, published 9-23-1998, GB 2252838, published 8-19-1992, and U.S. Pat. App. Pub. No. 2003/091618 (Seth et ak). However, in some of these cases, the change is provided in a random fashion, for example, by an impact during the use of the film that cannot provide a predetermined pattern or image. A change in the microporous structure by impact may also not be permanent. In other cases, the change is only provided along the edge of a film and therefore does not provide a see-through region within an opaque, microporous region.

In some embodiments, the microporous thermoplastic film comprises upstanding posts on its first major surface. In some of these embodiments, the article of the present disclosure is a mechanical fastener. In some embodiments, the mechanical fastening elements of the mechanical fastener are male fastening elements. In some of these embodiments, the male fastening elements comprise upstanding posts having bases attached to the first major surface. The first major surface and the upstanding posts are typically integral (that is, formed at the same time as a unit, unitary). The microporous thermoplastic film is typically in the form of a sheet or web that may have an essentially uniform thickness with the upstanding posts directly attached to the microporous thermoplastic film.

Upstanding posts on a thermoplastic film can be made, for example, by conventional extrusion through a die and cast molding techniques. In some embodiments, a thermoplastic composition is fed onto a continuously moving mold surface with cavities having the inverse shape of the upstanding posts. The thermoplastic composition can be passed between a nip formed by two rolls or a nip between a die face and roll surface, with at least one of the rolls having the cavities (i.e., at least one of the rolls is a tool roll). Pressure provided by the nip forces the composition into the cavities. In some embodiments, a vacuum can be used to evacuate the cavities for easier fdling of the cavities. The nip has a gap that is typically large enough such that a coherent film is formed over the cavities. The mold surface and cavities can optionally be air or water cooled before stripping the integrally formed film and upstanding posts from the mold surface such as by a stripper roll.

Suitable tool rolls can be made, for example, by forming (e.g., by computer numerical control with drilling, photo etching, using galvanic printed sleeves, laser drilling, electron beam drilling, metal punching, direct machining, or lost wax processing) a series of holes having the inverse shape of the upstanding posts into the cylindrical face of a metal mold or sleeve. Other suitable tool rolls include those formed from a series of plates defining a plurality of post-forming cavities about its periphery such as those described, for example, in U.S. Pat. No. 4,775,310 (Fischer). Cavities may be formed in the plates by drilling or photoresist technology, for example. Other suitable tool rolls may include wire- wrapped rolls, which are disclosed along with their method of manufacturing, for example, in U.S. Pat. No. 6,190,594 (Gorman et al.). Another example of a method for forming a thermoplastic film with upstanding posts includes using a flexible mold belt defining an array of upstanding post-shaped cavities as described in U.S. Pat. No. 7,214,334 (Jens et al.). Yet other useful methods for forming a thermoplastic film with upstanding posts can be found in U.S. Pat. Nos. 6,287,665 (Hammer), 7,198,743 (Tuma), and 6,627,133 (Tuma).

The upstanding posts, which may be made, for example, by any of the methods described above, may have a shape that tapers, for example, from base portion attached to the film to a distal tip. The base portion may have a larger width dimension than the distal tip, which may facilitate the removal of the post from the mold surface in the methods described above.

Male fastening elements on a microporous thermoplastic film disclosed herein may have loop- engaging heads that have an overhang or may be upstanding posts having distal tips that can be formed into loop-engaging heads, if desired. The term "loop-engaging" as used herein relates to the ability of a male fastening element to be mechanically attached to a loop material. Generally, male fastening elements with loop-engaging heads have a head shape that is different from the shape of the post. For example, the male fastening element may be in the shape of a mushroom (e.g., with a circular or oval head enlarged with respect to the stem), a hook, a palm-tree, a nail, a T, or a J (e.g., as shown and described in U. S. Pat. No. 5,953,797 (Provost et al.). The loop-engageability of male fastening elements may be determined and defined by using standard woven, nonwoven, or knit materials. A region of male fastening elements with loop-engaging heads generally will provide, in combination with a loop material, at least one of a higher peel strength, higher dynamic shear strength, or higher dynamic friction than a region of posts without loop-engaging heads. Typically, male fastening elements that have loop-engaging heads have a maximum thickness dimension (in either dimension normal to the height) of up to about 1 (in some embodiments, 0.9, 0.8, 0.7, 0.6, 0.5, or 0.45) millimeter.

In some embodiments, the distal tips of the upstanding posts that are formed according to any of the above methods are deformed to form caps with loop-engaging overhangs. A combination heat and pressure, sequentially or simultaneously, may be used to deform the distal tips of the posts to form caps.

In some embodiments, deforming comprises contacting the distal tips with a heated surface. The heated surface may be a flat surface or a textured surface such as that disclosed in 6,708,378 (Parellada et al.) or U.S. Pat. No. 5,868,987 (Kampfer et al.). In some embodiments, wherein the film with upstanding posts is a web of indefinite length, the deforming comprises moving the web in a first direction through a nip having a heated surface member and an opposing surface member such that the heated surface member contacts the distal tips. In these embodiments, the heated surface may be, for example, a capping roll. In some embodiments, the surface used to contact the distal tips is not heated. In these embodiments, the deformation is carried out with pressure and without heating. In some embodiments, the heated surface may be a heated roll opposite a curved support surface forming a variable nip having a variable nip length as described, for example, in U. S. Pat. No. 6,368,097 (Miller et al.). The curved support surface may curve in the direction of the heated roll, and the heated roll may include a feeding mechanism for feeding the film with upstanding posts through the variable nip to compressively engage the web between the heated roll and the support surface.

Another suitable method for forming a microporous thermoplastic film with upstanding posts is profile extrusion, which is described, for example, in U.S. Pat. No. 4,894,060 (Nestegard). In this method a flow stream of a thermoplastic composition is passed through a patterned die lip (e.g., cut by electron discharge machining) to form a web having downweb ridges. The ridges are then transversely sliced at spaced locations along the extension of the ridges to form upstanding posts with a small separation caused by the cutting blade. It should be understood that "upstanding posts" do not include such ridges before they are cut. However, the patterned die lip may be considered a tool to provide a film having upstanding posts on a first major surface. The separation between the upstanding posts is then increased by stretching the film in the direction of the ridges using one of the stretching methods described above. The ridges themselves would also not be considered "loop-engaging" because they would not be able to engage loops before they are cut and stretched. In some embodiments, methods according to the present disclosure do not include cutting ribs (e.g., made by profile extrusion).

In addition to the continuous methods described above, it is also envisioned that films with upstanding posts can be prepared using batch processes (e.g., single piece injection molding). The film may have any suitable dimension, but length (L) and width (W) dimensions of at least 10 cm may be useful.

The upstanding posts, in any of the embodiments disclosed herein, which may be made, for example, by any of the methods described above, may have a variety of cross-sectional shapes. For example, the cross-sectional shape of the post may be a polygon (e.g., square, rectangle, hexagon, or pentagon), which may be a regular polygon or not, or the cross-sectional shape of the post may be curved (e.g., round or elliptical).

In some embodiments, the upstanding posts have a maximum height (above the fdm) of up to 3 millimeters (mm), 1.5 mm, 1 mm, or 0.5 mm and, in some embodiments, a minimum height of at least 0.05 mm, 0.075 mm, 0.1 mm, or 0.2 mm. In some embodiments, the posts have aspect ratio (that is, a ratio of height over a width dimension) of at least about 2:1, 3: 1, or 4:1. The aspect ratio may be, in some embodiments, up to 10:1. For posts with caps, the caps are typically larger in area than the cross- sectional area of the posts. A ratio of a width dimension of the cap to the post measured just below the cap is typically at least 1.5: 1 or 3: 1 and may be up to 5: 1 or greater. The capped posts are typically shorter than the posts before capping. In some embodiments, the capped posts have a height (above the fdm) of at least 0.025 mm, 0.05 mm, or 0.1 mm and, in some embodiments, up to 2 mm, 1.5 mm, 1 mm, or 0.5 mm. The posts, which may be capped or not, may have a cross-section with a maximum width dimension of up to 1 (in some embodiments, up to 0.75, 0.5, or 0.45) mm. In some embodiments, the posts have a cross-section with a width dimension between 10 pm and 250 pm. The term "width dimension" should be understood to include the diameter of a post with a circular cross-section. When the post has more than one width dimension (e.g., in a rectangular or elliptical cross-section shaped post or a post that tapers as described above), the aspect ratio described herein is the height over the largest width dimension.

The upstanding posts are typically spaced apart on the backing. The term "spaced-apart" refers to posts that are formed to have a distance between them. The bases of "spaced-apart" posts, where they are attached to the fdm, do not touch each other before or after stretching the fdm when the fdm is in an unbent configuration. In the mechanical fastener according to and/or made according to the present disclosure, the spaced-apart upstanding posts have an initial density (i.e., before any stretching of the fdm) of at least 10 per square centimeter (cm²) (63 per square inch in²). For example, the initial density of the posts may be at least 100/cm² (635/in²), 248/cm² (1600/in²), 394/cm² (2500/in²), or 550/cm² (3500/in²). In some embodiments, the initial density of the posts may be up to 1575/cm² (10000/in²), up to about 1182/cm² (7500/in²), or up to about 787/cm² (5000/in²). Initial densities in a range from 10/cm² (63/in²) to 1575/cm² (10000/in²) or 100/cm² (635/in²) to 1182/cm² (7500/in²) may be useful, for example. The spacing of the upstanding posts need not be uniform. After stretching the density of the upstanding posts is less than the initial density of the upstanding posts. In some embodiments, the upstanding posts have a density after stretching of at least 2 per square centimeter (cm²) (13 per square inch in²). For example, the density of the posts after stretching may be at least 62/cm² (400/in²), 124/cm² (800/in²), 248/cm² (1600/in²), or 394/cm² (2500/in²). In some embodiments, the density of the posts after stretching may be up to about 1182/cm² (7500/in²) or up to about 787/cm² (5000/in²). Densities after stretching in a range from 2/cm² (13/in²) to 1182/cm² (7500/in²) or 124/cm² (800/in²) to 787/cm² (5000/in²) may be useful, for example. Again, the spacing of the posts need not be uniform. Mechanical fasteners, which are also called hook and loop fasteners, typically include a plurality of closely spaced upstanding projections with loop-engaging heads useful as hook members, and loop members typically include a plurality of woven, nonwoven, or knitted loops. Mechanical fasteners are widely used, for example, in personal hygiene articles (that is, wearable disposable absorbent articles) to fasten such articles around the body of a person. In typical configurations, a hook strip or patch on a fastening tab attached to the rear waist portion of a diaper or incontinence garment, for example, can fasten to a landing zone of loop material on the front waist region, or the hook strip or patch can fasten to the backsheet (e.g., nonwoven backsheet) of the diaper or incontinence garment in the front waist region. However, mechanical fasteners are useful for providing releasable attachment in numerous applications (e.g., abrasive discs, assembly of automobile parts, as well as personal hygiene articles).

The article of the present disclosure includes a first adhesive having a first color disposed on the second major surface of the microporous thermoplastic film. In some embodiments, the article includes a second adhesive having a second color other than the first color disposed on the second major surface of the microporous thermoplastic film. The number of adhesives and their colors are not limited, and the article may include at least 3, 4, 5, 6, 7, 8, 9, or 10 different adhesives having different colors. Each of the colors may be other than white, or at least one of the adhesives may be white in color. The adhesives may be opaque or transparent. The adhesive may be selected such that it has sufficient peel strength to attach (e.g., permanently attach) the second major surface of the microporous thermoplastic film to a substrate such as any of those described herein.

The first, second, or any other adhesive useful for practicing the present disclosure may be any conventional adhesive, including pressure sensitive adhesives (PSAs) and non-pressure sensitive adhesives. PSAs are well known to those of ordinary skill in the art to possess properties including the following: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be cleanly removable from the adherend. Materials that have been found to function well as PSAs are polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. One method useful for identifying pressure sensitive adhesives is the Dahlquist criterion. This criterion defines a pressure sensitive adhesive as an adhesive having a 1 second creep compliance of greater than 1 x 10⁶ cm²/dyne as described in Handbook of Pressure Sensitive Adhesive Technology, Donatas Satas (Ed.), 2nd Edition, p. 172, Van Nostrand Reinhold, New York, NY, 1989. Alternatively, since modulus is, to a first approximation, the inverse of creep compliance, pressure sensitive adhesives may be defined as adhesives having a storage modulus of less than about 1 x 10⁶ dynes/cm².

The adhesive(s), in some embodiments, the PSA(s), may be hot-melt processable, solvent-based , or water-based. Suitable PSAs include acrylic resin and natural or synthetic rubber-based adhesives. Examples of suitable PSAs include natural rubber-, acrylic-, block copolymer-, silicone-, polyisobutylene-, polyvinyl ether-, polybutadiene-, or and urea-based pressure sensitive adhesive and combinations thereof. These PSAs can be prepared, for example, as described in Adhesion and Adhesives Technology, Alphonsus V. Pocius, Hanser/Gardner Publications, Inc., Cincinnati, Ohio, 1997, pages 216 to 223, Handbook of Pressure Sensitive Adhesive Technology, Donatas Satas (Ed.), 2nd Edition, Van Nostrand Reinhold, New York, NY, 1989, Chapter 15, and U.S. Pat. No. Re 24,906 (Ulrich).

Examples of useful rubber-based adhesives include those made from butyl rubber, styrene butadiene (SB), styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene- ethylene/butylene -styrene (SEBS), and styrene-ethylene/propylene-styrene that may optionally contain diblock components such as styrene isoprene and styrene butadiene. Ethylene/vinyl acetate may also be a useful as an adhesive.

In some embodiments, the adhesive(s), in some embodiments, the PSA(s), can include a tackifier. The tackifier can comprise at least one of rosin, a rosin ester, an ester of hydrogenated rosin, a polyterpene (e.g., those based on a-pinene, b-pinene, or limonene), an aliphatic hydrocarbon resin (e.g., those based on cis- or trans-piperylene, isoprene, 2-methyl-but-2-ene, cyclopentadiene, dicyclopentadiene, or combinations thereof), an aromatic resin (e.g. those based on styrene, a-methyl styrene, methyl indene, indene, coumarone, or combinations thereof), or a mixed aliphatic-aromatic hydrocarbon resin. Any of these aromatic tackifying resins may be hydrogenated (e.g., partially or completely).

A number of additives may also be useful in the adhesive(s), in some embodiments, PSA(s). Examples of such additives include antioxidants, such as hindered phenols, amines, and sulfur and phosphorous hydroperoxide decomposers; inorganic fillers such as talc, zinc oxide, titanium dioxide, aluminum oxide, and silica; stabilizers (e.g., ultraviolet absorbers, hindered amine light stabilizers, and heat stabilizers); propellants; fire retardants; and viscosity adjusting agents. The adhesive(s) may be colored with pigments, dyes, or a combination thereof.

The adhesive(s) may be applied to the second major surface of the microporous thermoplastic film using a variety of different spraying, printing, or coating techniques. Spray adhesives may be applied as aerosols from spray cans, for example. Rotary printing techniques such as flexographic printing and gravure printing and other techniques such as screen printing may also be useful. Coating techniques as roll coating, bar coating, and extrusion coating are also useful. In a roll coating process, an adhesive composition may be applied to a coating roll from an adhesive trough, and the thickness of the adhesive can be controlled using a metering or doctor roll and/or doctor blade. Many of these spraying, printing, and coating techniques can be used with solvent-based or water-based adhesives, in which the solvent or water is later removed by drying. Useful hot-melt processes for preparing and coating adhesives include that described, for example, in U.S. Pat. No. 5,539,033 (Bredahl et al.) for non thermoplastic elastomers. Spraying and printing using any of the techniques described above may be useful for applying multiple adhesives having multiple colors to the second major surface of the microporous thermoplastic film so that more than one color can be seen through the see-through regions of lower porosity in the microporous thermoplastic film.

Multiple adhesives having multiple colors may also be coextruded onto the second major surface of the microporous thermoplastic film. Side-by-side co-extrusion can be carried out by a number of useful methods using solvent-based, water-based, or hot melt coated adhesives. For example, U.S. Pat. Nos. 4,435,141 (Weisner et al.) and 6,669,887 (Hilston et al.) describes a die with die bars for making a multi-component film having alternating segments in the film cross-direction. Management of the flow of different adhesive compositions into side-by-side lanes can also be carried out using a single manifold die with a distribution plate in contrast to approaches that require multiple dies to achieve side-by-side co extrusion. Further details about the die and the distribution plate can be found, for example, in U.S. Pat. Appl. Pub. No. 2012/0308755 (Gorman et al.). Side-by-side co-extruded films can also be made by other extrusion dies that comprise a plurality of shims and have two cavities for molten polymer, such as those dies described, for example, in Int. Pat. App. Pub. No. WO 2011/119323 (Ausen et al.) and U.S. Pat. App. Pub. No. 2014/0093716 (Hanschen et al.). Extrusion dies for side-by-side co-extrusion are also available from Nordson Extrusion Dies Industries, Chippewa Falls, Wis.

Furthermore, any of the spraying, printing, and coating methods described above for applying one or more colored adhesives onto the second major surface of the microporous, thermoplastic film can be useful for applying one or more colored adhesives to a substrate, including any of those described below. The substrate can then be adhered to the second major surface of the microporous, thermoplastic film using the one or more adhesives.

In the article of the present disclosure, a portion of the first adhesive or multiple adhesives is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film. The visibility of the first adhesive or multiple adhesives is facilitated by color contrast between the first major surface of the microporous thermoplastic film and the adhesive or adhesives. If the opaque region of the microporous thermoplastic film is white, and the see-through regions of lower porosity are colorless, the actual color(s) of the adhesive(s) is visible through the see- through regions of lower porosity. In these embodiments, typically the first color is other than white although at least one of multiple colored adhesives may be white. In some embodiments, the opaque region of the microporous thermoplastic film is a color other than white, and the see-through regions of lower porosity are not colorless. In these embodiments, the color(s) of the adhesive(s) visible through the see-through regions of lower porosity may be altered by the color of the see-through regions. The color observed in the see-through regions of lower porosity may be a combination of the color of the adhesive and the color of the see-through regions in the microporous thermoplastic film.

FIG. 2 is a perspective view of an embodiment of a personal hygiene article incorporating an article according to the present disclosure. The personal hygiene article is a diaper 60 having an essentially hourglass shape. The diaper comprises an absorbent core 63 between a liquid permeable top sheet 61 that contacts the wearer's skin and an outwardly facing liquid impermeable back sheet 62. Diaper 60 has a rear waist region 65 having two fastening tabs 70 arranged at the two longitudinal edges 64a, 64b of diaper 60. The diaper 60 may comprise an elastic material 69 along at least a portion of longitudinal edges 64a and 64b to provide leg cuffs. When attaching the diaper 60 to a wearer's body, the user's ends 70b of fastening tabs 70 can be attached to a target area 68 comprising fibrous material 72 arranged on the backsheet 62 of the front waist region 66. The longitudinal direction "L" of the personal hygiene article (e.g., diaper 60) refers to the direction that the article extends from the front to rear of the user. Therefore, the longitudinal direction refers to the length of the personal hygiene article between the rear waist region 65 and the front waist region 66. The lateral direction of the personal hygiene article (e.g., diaper 60) refers to the direction that the article extends from the left side to the right side (or vice versa) of the user (i.e., from longitudinal edge 64a to longitudinal edge 64b in the embodiment of FIG. 2).

An example of a cross-section of the fastening tab 70 taken through line 2A-2A in FIG. 2 is shown in FIG. 2A. Fastening tab 70 has a manufacturer's end 70a secured to the diaper rear waist region 65 and a user's end 70b that includes the fastening portion. The manufacturer's end 70a corresponds to the part of fastening tab 70 which is fixed or secured to the diaper 60 during the manufacture of the diaper 60. The user's end is typically gripped by the user when attaching the diaper 60 to the wearer and is typically not fixed to the diaper during manufacturing. Fastening tab 70 usually extends beyond longitudinal edges 64a, 64b of the diaper 60.

In the embodiment illustrated in FIG. 2A, fastening tab 70 comprises a tape backing 75 bearing adhesive 76. Adhesive 76 joins optional mechanical fastener 80 to the tape backing 75 and joins the tape backing 75 to the rear waist region 65 of the diaper. In the illustrated embodiment, exposed adhesive 77 may be present between the mechanical fastener 80 and the diaper rear waist region 65. Fastening tab 70 further comprises release tape 79 to contact the exposed part of adhesive 77 when the user’s end 70b is folded onto diaper rear waist region 65 (e.g., during packaging and shipping of diaper 60 as shown for the fastening tab 70 at longitudinal edge 64b). As shown in FIG. 2A, the release tape 79 is attached to the tape backing 75 (in some embodiments, directly attached as shown) along only one of its edges, leaving the opposite edge to be joined to the diaper rear waist region 65 during the manufacture of the personal hygiene article. The release tape 79 therefore is generally understood in the art to be permanently attached to the fastening tab 70 and ultimately to the personal hygiene article. In this way, release tape 79 is understood to be different from a release liner that is temporarily placed over exposed adhesive and discarded when the adhesive is in use. The release tape 79 may be joined to the tape backing 75 and diaper rear waist region 65 using adhesive 76. Other configurations of release tape 79 are possible depending on the configuration of the attachment of the fastening tab 70 to diaper 60. The tape backing 75 at the user's end 70b of the fastening tab 70 may exceed the extension of the adhesive 76 and optional mechanical fastener 80 thereby providing a fmgerlift.

In some embodiments, when a fastening tab is manufactured, the release tape 79 is folded back on itself and can be applied to the tape backing 75 in a pre-folded condition although it is possible in some cases to fold the release tape 79 after attaching one end to the tape backing. The release tape 79 may also be attached to the tape backing 75 using a separate strip or patch (not shown). The strip or patch can be made from a material such as any of the fdms and fibrous materials described herein below. When the release tape 79 is coated with an adhesive layer on a surface opposite the release surface, the strip or patch can adhere to both the release tape 79 and the tape backing 75 to connect them.

When adhesive 76 is a first adhesive having a first color, FIG. 2 illustrates a variety of embodiments of the article of the present disclosure in the same diaper 60. As illustrated in FIG. 2 and the expanded view of the fastening tab 70 shown in FIG. 2B, release tape 79 includes a microporous thermoplastic film having a first major surface visible in FIGS. 2 and 2B. Release tape 79 includes an opaque, microporous region 12 and see-through regions 14 of lower porosity. A portion of the first adhesive 76 is visible through the see-through regions 14 of lower porosity when viewed from the first major surface of the microporous thermoplastic film. Also, in the illustrated embodiment, tape backing 75 includes a thermoplastic microporous film having an opaque, microporous region 22 and see-through regions 24 of lower porosity. A portion of the first adhesive 76 is visible through the see-through regions 24 of lower porosity when viewed from the first major surface of the microporous thermoplastic film, which in FIG. 2B is opposite to the surface that is shown. Furthermore, mechanical fastener 80 includes microporous thermoplastic film having a first major surface visible in FIGS. 2 and 2B. Mechanical fastener 80 includes an opaque, microporous region 32 and see-through regions 34 of lower porosity. A portion of the first adhesive 76 is visible through the see-through regions 34 of lower porosity when viewed from the first major surface of the microporous thermoplastic film. Target area 68 includes a mechanical fastener including a microporous thermoplastic film having a first major surface visible in FIG. 2. Target area 68 includes an opaque, microporous region 42 and see-through regions 44 of lower porosity. When the target area 68 is attached to the diaper 60 with a first adhesive having a first color, a portion of the first adhesive 76 is visible through the see-through regions 44 of lower porosity when viewed from the first major surface of the microporous thermoplastic film. In any of these embodiments, there may also be a second adhesive with a second color different from the first color, for example, as a portion of the adhesive 76. A portion of the second adhesive may be visible through the see-through regions 14, 24, 34 of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

As described herein, in some embodiments, the article of the present disclosure comprises a substrate, wherein the first and optionally second adhesive adhere the microporous thermoplastic film to the substrate. In the embodiments illustrated in FIGS. 2, 2A, and 2B, the substrate is a component of the personal hygiene article 60. For example, for the mechanical fastener 80, the substrate is tape backing 75, and for release tape 79, the substrate can include diaper rear waist region 65 and tape backing 75. For the target area 68, the substrate is the backsheet 62 of the diaper 60.

In personal hygiene articles incorporating an article according to the present disclosure, such as that shown in FIG. 2, the topsheet 61 is typically permeable to liquid and designed to contact a wearer's skin, and the outwardly facing backsheet 62 is typically impermeable to liquids. There is typically an absorbent core 63 encased between the topsheet and the backsheet. Various materials can be useful for the topsheet 61, the backsheet 62, and the absorbent core 63 in an absorbent article according to the present disclosure. Examples of materials useful for topsheets 61 include apertured plastic fdms, woven fabrics, nonwoven webs, porous foams, and reticulated foams. In some embodiments, the topsheet 61 is a nonwoven material. Examples of suitable nonwoven materials include spunbond or meltblown webs of fiber forming polymer filaments (e.g., polyolefin, polyester, or polyamide filaments) and bonded carded webs of natural polymers (e.g., rayon or cotton fibers) and/or synthetic polymers (e.g., polypropylene or polyester fibers). The nonwoven web can be surface treated with a surfactant or otherwise processed to impart the desired level of wettability and hydrophilicity. The backsheet 62 is sometimes referred to as the outer cover and is the farthest layer from the user. The backsheet 62 functions to prevent body exudates contained in absorbent core from wetting or soiling the wearer's clothing, bedding, or other materials contacting the diaper. The backsheet 62 can be a thermoplastic film (e.g., a poly(ethylene) film). The thermoplastic film may be embossed and/or matte finished to provide a more aesthetically pleasing appearance. The backsheet 62 can also include woven or nonwoven fibrous webs, for example, laminated to the thermoplastic films or constructed or treated to impart a desired level of liquid impermeability even in the absence of a thermoplastic film. Suitable backsheets 62 also include vapor or gas permeable microporous "breathable" materials that are substantially impermeable to liquid. Suitable absorbent cores 63 include natural, synthetic, or modified natural polymers that can absorb and hold liquids (e.g., aqueous liquids). Such polymers can be crosslinked (e.g., by physical entanglement, crystalline domains, covalent bonds, ionic complexes and associations, hydrophilic associations such as hydrogen bonding, and hydrophobic associations or Van der Waals forces) to render them water insoluble but swellable. Such absorbent materials are usually designed to quickly absorb liquids and hold them, usually without release. Examples of suitable absorbent materials useful in absorbent articles disclosed herein include wood pulp or other cellulosic materials and super absorbent polymers (SAP). Elastic materials, such as elastic material 69 shown in FIG. 2, are typically polymers from which films or strands (0.002 to 0.5 mm thick) can be made that exhibit recovery from stretching or deformation. Examples of elastic materials include thermoplastic elastomers such as ABA block copolymers, polyurethane elastomers, polyolefin elastomers (e.g., metallocene polyolefin elastomers), polyamide elastomers, ethylene vinyl acetate elastomers, polyester elastomers, and combinations thereof.

Referring again to FIG. 2, backsheet 62 includes a microporous thermoplastic film having a first major surface visible in the illustrated embodiment. At least a component of the backsheet includes an opaque, microporous region 52 and see-through regions 54 of lower porosity. In this embodiment of the article of the present disclosure that includes a substrate, the substrate is an absorbent core 63 of the personal hygiene article 60, and the microporous thermoplastic film is a component of the backsheet 62 of the personal hygiene article 60. When the backsheet 62 is attached to the absorbent core 63 with a first adhesive having a first color and optionally a second adhesive having a second color, a portion of the first adhesive and optionally the second adhesive is visible through the see-through regions 54 of lower porosity when viewed from the first major surface of the microporous thermoplastic film. The backsheet 62 may consist of microporous thermoplastic film useful in the article of the present disclosure, or the backsheet 62 can also include woven or nonwoven fibrous webs, for example, laminated to the microporous thermoplastic film as described above. For example, a see-through nonwoven can be attached to a microporous thermoplastic film described herein with a colorless adhesive or by thermal or ultrasonic bonding. The microporous thermoplastic film can then be adhered to the absorbent core 63 with the first adhesive and optionally the second adhesive. A portion of the first adhesive and optionally the second adhesive is visible through the see-through regions 54 of lower porosity when viewed through the see-through nonwoven and the microporous thermoplastic film.

In some embodiments of the article disclosed herein (e.g., in the target area 68 shown in FIG. 2) the article includes female fastening elements, for example, loops disposed on the first major surface of the first layer. The loops may be part of a fibrous structure formed by any of several methods such as weaving, knitting, warp knitting, weft insertion knitting, circular knitting, or methods for making nonwoven structures. In some embodiments, the loops are included in a nonwoven web or a knitted web. The term “non-woven” refers to a material having a structure of individual fibers or threads that are interlaid but not in an identifiable manner such as in a knitted fabric. Examples of non-woven webs include spunbond webs, spunlaced webs, airlaid webs, meltblown web, and bonded carded webs. Useful loop materials may be made of natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., thermoplastic fibers), or a combination of natural and synthetic fibers. Examples of suitable materials for forming thermoplastic fibers include polyolefins (e.g., polyethylene, polypropylene, polybutylene, ethylene copolymers, propylene copolymers, butylene copolymers, and copolymers and blends of these polymers), polyesters, and polyamides. The fibers may also be multi-component fibers, for example, having a core of one thermoplastic material and a sheath of another thermoplastic material.

Referring again to FIG. 2, examples of loop tapes that may suitably be applied to the target area 68 to provide an exposed fibrous material 72, are disclosed, for example, in U. S. Pat. Nos. 5,389,416 (Mody et al.) and 5,256, 231 (Gorman et al.) and EP 0,341,993 (Gorman et ah). As described in U.S. Pat. No. 5,256,231 (Gorman et al.), the fibrous layer in a loop material according to some embodiments can comprise arcuate portions projecting in the same direction from spaced anchor portions on the first major surface of the first layer of thermoplastic film. Any of the fibrous loop materials may be extrusion- bonded, adhesive-bonded, and/or sonically-bonded to the microporous thermoplastic film. For loop materials extrusion bonded to the film, stretching can be carried out after the extrusion bonding. Stretching the film may be carried out before or after adhesively or sonically bonding the fibrous loop material to the film.

Although illustrated diaper 60 in FIG. 2 includes backsheet 62, release tape 79, tape backing 75, target area 68, and mechanical fastener 80 that all have an opaque, microporous region and a see-through region of lower porosity through which the fist and optionally second adhesives are visible, any one of these or any combination of two of these may be present in a personal hygiene article. Also, in FIGS. 2 and 2B, each of the backsheet 62, release tape 79, tape backing 75, and mechanical fasteners 80 and 72 include a see-through region 54, 14, 24, 34, and 44 that is included in a pattern of see-through regions although this is not a requirement. There may be more than one see-through region within the opaque, microporous region that does not necessarily form a repeating pattern. For example, multiple see-through regions in the form of alphabetical letters can be used together to form a word. The see-through region(s) 54, 14, 24, 34, and 44 or, in some embodiments, the pattern of see-through regions can be in the form of a number, picture, symbol, geometric shape, alphabetical letter, bar code, or any combination thereof. Any of these numbers, pictures, symbols, geometric shapes, alphabetical letters, or combination thereof may be part of a company name, logo, brand name, or trademark picture if desired.

The microporous regions in the articles of the present disclosure provide advantages other than the color contrast between the microporous region and the see-through region of lower porosity. The ability of the microporous fdms to block the transmission of light (e.g., by scattering) allows them to be detected in inspection systems that rely upon shining a light onto a substrate and detecting the amount of light received from the area of the irradiated substrate. For example, in the manufacture of a personal hygiene article, the presence or position of a microporous thermoplastic fdm disclosed herein or a portion thereof incorporated into the article can be detected because of its ability to block ultraviolet, visible, and/or infrared light. The response of the microporous thermoplastic fdm to irradiation by at least one of ultraviolet, visible, or infrared light is evaluated. Subsequently, during manufacturing a personal hygiene article can be irradiated, and at least one of the ultraviolet, visible, or infrared radiation received from the irradiated personal hygiene article can be detected and analyzed for the predefined response of the microporous thermoplastic film. The position of the microporous thermoplastic film can be determined using an image analyzer that can detect predefined variations in grayscale values, for example, that correspond to the positions of the microporous thermoplastic film and other components. The ability of the microporous thermoplastic film disclosed herein to scatter infrared light allows it to be detected even when it is between other layers of materials in the composite article. For more information regarding methods of detecting microporous films in a composite article, see U.S. Pat. No. 9,278,471 (Chandrasekaran et ak).

Furthermore, microporous thermoplastic films tend to have lower densities than their non- microporous counterparts. A low-density microporous thermoplastic film feels softer to the touch than films having comparable thicknesses but higher densities. The density of the film can be measured using conventional methods, for example, using helium in a pycnometer. In some embodiments, stretching a film containing beta-spherulites provides a decrease in density of at least three percent. In some embodiments, this stretching provides at decrease in density of at least 5 or 7.5 percent. For example, the stretching provides at decrease in density in a range from 3 to 15 percent or 5 to 10 percent. A percentage change in density that results from stretching the film is calculated by [(density before stretching - density after stretching)/density before stretching] times 100. The softness of the film can be measured, for example, using Gurley stiffness. The article according to the present disclosure can be converted to any desired size and shape.

The article may be in the form of a fastening tab as shown in FIGS. 2, 2A, and 2B, or the article may be attached on the ears of a personal hygiene article. Also, the mechanical fastener useful for practicing the present disclosure can be converted to any desired size and shape. For example, a personal hygiene article having ears may include a larger patch of male fastening elements relative to a mechanical fastener patch on a fastening tab. Also, a personal hygiene article can have two smaller target zones of loop material along the longitudinal edges of the back sheet instead of the large target area 68 shown in FIG. 2.

In the open configuration shown in FIG. 2A, the geometry of the tape backing 75 and the release tape 79 results in a Y-shaped bond being formed around the diaper edge in the rear waist region 65, which is often referred to in the industry as a Y-bond. However, other configurations of a release surface on a tape are possible, which tapes may or may not include a mechanical fastener. For example, a tape may be partially coated on its second surface with a release coating (e.g., a silicone, fluorochemical, or carbamate coating) and partially coated on its first surface with an adhesive. A fastening tab may be cut from such a tape and attached through its proximal end to the edge of a diaper with its release surface exposed. A distal end of the tab may be folded into a loop so that the adhesive is in contact with the release coating. Such a configuration is described in U.S. Pat. No. 3,930,502 (Tritsch). In another example, the tape may be partially coated with a release coating and partially coated with an adhesive on the same surface. A fastening tab may be cut from the tape and attached through its proximal end to the edge of a diaper with adhesive on its distal end, and the distal end of the tab may be folded back onto itself so that the adhesive is in contact with the release coating. The tape backing may be a continuous piece as shown at 75 in FIG. 2A, or when a stretchable film is desired, for example, there may be two pieces of a backing both attached to an elastic film as described in Int. Pat. Appl. Pub. No. WO 2004/075803 (Loescher et ak). Still other useful configurations of fastening tabs are described in U.S. Pat. Appl. Pub. No. 2007/0286976 (Selen et ak). In any of the embodiments of the article of the present disclosure in which the article is a release tape or includes a release surface, the article is typically provided with a release coating (e.g., a silicone, fluorochemical, or carbamate coating).

Personal hygiene articles (e.g., incontinence articles and diapers) according to the present disclosure and/or including an article of the present disclosure may have any desired shape such as a rectangular shape, a shape like the letter I, a shape like the letter T, or an hourglass shape. The personal hygiene article may also be a refastenable pants-style diaper with fastening tabs 70 along each longitudinal edge. In some embodiments, including the embodiment shown in FIG. 2, the topsheet 61 and backsheet 62 are attached to each other and together form chassis all the way out to the first and second longitudinal opposing edges 64a and 64b. In some embodiments, only one of the topsheet 61 or the backsheet 62 extends to the first and second longitudinal opposing edges 64a and 64b. In other embodiments, the chassis can include separate side panels that are attached to the sandwich of at least topsheet 61, backsheet 62, and absorbent core 63 during manufacturing of the absorbent article, for example, to form ear portions. The side panels can be made of a material that is the same as the topsheet 61 or backsheet 62 or may be made from a different material. In these embodiments, the side panels also form part of the chassis.

The article of the present disclosure may also be a sanitary napkin. A sanitary napkin typically includes a backsheet that is intended to be placed adjacent to the wearer's undergarment. Adhesive or mechanical fasteners are provided on the backsheet to attach the sanitary napkin to the wearer’s undergarment. The sanitary napkin typically also includes a topsheet and absorbent core. The backsheet, topsheet, and absorbent core can be made from any of the materials described above for these components in diapers or incontinence articles. The sanitary napkin may have any desired shape such as an hourglass, keyhole, or generally rectangular shape. The backsheet may also include flaps that are intended to wrap around to the opposite side of the wearer’s undergarment. The backsheet includes a microporous thermoplastic fdm having an opaque, microporous region and a see-through region of lower porosity. A first adhesive having a first color and optionally a second adhesive are disposed on the second major surface of the microporous thermoplastic film, and a portion of the first adhesive and optionally the second adhesive are visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film. The see-through region of lower porosity or, in some embodiments, the pattern of see-through regions of lower porosity can be in the form of a number, picture, symbol, geometric shape, alphabetical letter, bar code, or any combination thereof. Any of these numbers, pictures, symbols, geometric shapes, alphabetical letters, or combination thereof may be part of a company name, logo, brand name, or trademark picture if desired.

Another embodiment of an article of the present disclosure is shown in FIGS. 3, 3 A, and 3B in connection with a pants or shorts style incontinence article 200, which may be an infant diaper or adult incontinence article. After use of such a pants style incontinence article, it is typically tom apart along at least one of its seams 211 before rolling it up so that it does not have to be removed over the legs. The article of the present disclosure is in the form of disposal tape 202 in the illustrated embodiment.

Disposal tape 202 is used to hold a used (soiled) incontinence article in a rolled-up configuration after it has been tom along the seams 211 as shown in FIG. 3B. Although a variety of disposal tape constmctions may be useful, in the illustrated embodiment, the disposal tape 202 includes two adjacent first and second tape tab elements 204, 206 separated by slit 236. Each of the first and second tape tab element 204,206 is adhesively attached to a plastically deformable film 205, which is visible in FIG. 3B. More details about this disposal tape constmction can be found in Int. Pat. Appl. Pub. No. WO 2007/032965 (Dahm et ah). In the illustrated embodiment, the tape tab elements 204, 206 each includes a microporous thermoplastic film having an opaque, microporous region 222 and a see-through region of lower porosity 224. A first adhesive having a first color and optionally a second adhesive are disposed on the second major surface of the microporous thermoplastic film, and a portion of the first adhesive and optionally the second adhesive are visible through the see-through region of lower porosity 224 when viewed from the first major surface of the microporous thermoplastic film.. In this embodiment of the article of the present disclosure, the article includes a substrate, which in the illustrated embodiment is the plastically deformable film 205, the backsheet of the incontinence article 200, or a combination thereof. The see-through regions 224 of lower porosity are in the form of alphabetical letters in the illustrated embodiment. However, as described above, the see-through regions can be in the form of a number, picture, symbol, geometric shape, alphabetical letter, bar code, or any combination thereof. Any of these numbers, pictures, symbols, geometric shapes, alphabetical letters, or combination thereof may be part of a company name, logo, brand name, or trademark picture if desired.

Another embodiment of the article of the present disclosure is shown in FIG. 4. FIG. 4 is a side cross-section view of a roll of tape 300. Roll of tape 300 includes a microporous thermoplastic film 301 that has a first major surface 301a and second major surface 301b. Microporous film 300 also has an opaque, microporous region and see-through regions of lower porosity, which are not shown in the side view of FIG. 4. The roll of tape 300 further includes a first adhesive 302 disposed on the second major surface 301b of the microporous thermoplastic film 301. The first adhesive 302 has a first color. In some embodiments, the first color is other than white. The first adhesive may be opaque or transparent. Although not shown in FIG. 4, a portion of the first adhesive 302 is visible through the see-through regions of lower porosity when viewed from the first major surface 301a of the microporous thermoplastic film 301. Roll of tape 300 further includes a release coating 307 on the first major surface 301a of the microporous thermoplastic film 301. The release coating 307 can be provided, for example, by a fluorochemical, silicone, or carbamate. In some embodiments, a release liner (not shown) may be applied to the exposed adhesive 302 instead of or in addition to the release coating 307. The first adhesive 302 can be as described above in any of its embodiments. In some embodiments, the first adhesive 302 is a pressure sensitive adhesive. The article of the present disclosure also includes pieces cut from roll of tape 300 in a size appropriate to the desired application.

The roll 300 may have a variety of useful widths. In some embodiments, the width of the roll is at least 1.9 centimeter, at least 2.5 centimeters, or at least 5 centimeters. In some embodiments, the width of the roll is at least 10 centimeters, at least 45 centimeters, or at least 75 centimeters. The article of the present disclosure also includes pieces cut from roll of tape 300 in a size appropriate to the desired application.

In some embodiments, article of the present disclosure includes a substrate. A wide variety of substrates are useful in connection with the article of the present disclosure, including any of the components of the personal hygiene article described above. For example, the substrate may comprise woven webs, non-woven webs (e.g., spunbond webs, spunlaced webs, airlaid webs, meltblown web, and bonded carded webs), textiles, plastic films (e.g., single- or multilayered films, coextruded films, laterally laminated films, or films comprising foam layers), and combinations thereof. In some embodiments, the substrate is a fibrous material (e.g., a woven, nonwoven, or knit material). In some embodiments, the substrate comprises multiple layers of nonwoven materials with, for example, at least one layer of a meltblown nonwoven and at least one layer of a spunbonded nonwoven, or any other suitable combination of nonwoven materials. Or, the substrate may be a composite web comprising any combination of nonwoven layers and dense film layers. The substrate may be continuous (i.e., without any through-penetrating holes) or discontinuous (e.g. comprising through-penetrating perforations or pores).

In some embodiments of the article of the present disclosure, the substrate is an architectural article that can be integrated into a building or other structure. In some embodiments, the substrate is a wall, ceiling, window, or door. The microporous thermoplastic film may be a decorative film (e.g. wallpaper) applied to any of these substrates with a first adhesive have a first color and optionally a second adhesive having a second color.

FIG. 5 illustrates another embodiment of the article of the present disclosure and a method for making the article, wherein the article includes an architectural article as a substrate. The article 500 illustrated in FIG. 5 includes wall 503 as a substrate. The process for making the article 500 includes spraying a first adhesive 502, a second adhesive 504, and a third adhesive 506 onto the substrate. The first adhesive 502 has a first color, the second adhesive 504 has a second color other than the first color, and the third adhesive 506 has a third color other than the first and second colors. The first, second, and third adhesives can be either opaque or transparent. The first, second, and third colors may all be other than white, or one of the first, second, or third colors may be white. The first, second, and third adhesives 502, 504, 506 are applied to the wall 503 by spraying from spray cans 508a, 508b, and 508c. Article 500 includes a microporous thermoplastic film 501 that has opaque, microporous regions 512 and see-through regions 514 of lower porosity. The microporous thermoplastic film 501 is adhered to the wall 503 by the first, second, and third adhesives 502, 504, 506. In the illustrated embodiment, portions of the first adhesive 502, the second adhesive 504, and the third adhesive 506 are visible through the see-through regions 114 of lower porosity when viewed through the microporous thermoplastic film 501.

FIG. 5 illustrates an embodiment of a process of making the article of the present disclosure. The illustrated process includes spraying the adhesive (first, second, and third adhesives 502, 504, and 506 in the illustrated embodiment) onto the substrate and adhering the microporous thermoplastic film to the substrate (wall 503 in the illustrated embodiment). In another embodiment of the process, the process includes spraying the adhesive(s) onto the second surface of the microporous thermoplastic film and adhering the microporous thermoplastic film to the substrate. In other embodiments of the process, the adhesive(s) may be coated onto at least one of the microporous thermoplastic film or the substrate using any of the methods described above for coating adhesives. The microporous thermoplastic film and the substrate are then adhered together.

As shown in FIG. 5, colored adhesive can be applied to the substrate such as wall 503, and portions of the first 502, second 504, and third adhesives 506 are visible through the see-through regions of lower porosity when the microporous thermoplastic film is adhered to the wall. In this way, the present disclosure further provides wallpaper comprising a microporous thermoplastic film having first and second major surfaces, the microporous thermoplastic film comprising an opaque, microporous region and a see-through region of lower porosity. The inventors also contemplate that the substrate (e.g., wall 503) may also be colored by another method. For example, the substrate may have been painted with colored paint or multiple colored paints. In this embodiment, the substrate has at least one color, and the at least one color (e.g., colored paint or multiple colored paints) is visible through the see-through region of lower porosity of the microporous thermoplastic fdm. In this embodiment, the adhesive need not be a colored adhesive but may be colorless and transparent. In some embodiments of the wallpaper of the present disclosure, the microporous thermoplastic fdm comprises polypropylene, for example, as a homopolymer, copolymer, or blend as described above. Organizations are moving away from PVC flex wallpaper due to a ban on using such products. Microporous thermoplastic fdms made from polyolefins (e.g., polypropylene) provide a greener and more sustainable solution for wallpaper. The wallpaper of the present disclosure can also be useful as a protective film for protecting the substrate from physical damage and discoloration.

When a colored substrate is used, in some embodiments, a portion of the at least one color is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film. The visibility of the at least one color is facilitated by color contrast between the first major surface of the microporous thermoplastic film and the color or colors of the substrate. If the opaque region of the microporous thermoplastic film is white, the see-through regions of lower porosity are colorless, and the adhesive is transparent and colorless, the actual color(s) of the substrate is visible through the see-through regions of lower porosity. In these embodiments, typically the color is other than white although at least one of multiple colors on the substrate may be white. In some embodiments, the opaque region of the microporous thermoplastic film is a color other than white, and the see-through regions of lower porosity are not colorless. In some embodiments, the adhesive is transparent but not colorless. In these embodiments, the color(s) of the substrate visible through the see- through regions of lower porosity may be altered by the color of the see-through regions and/or the color of the transparent adhesive. The color observed in the see-through regions of lower porosity may be a combination of the color of the substrate, the color of the adhesive, and the color of the see-through regions in the microporous thermoplastic film.

In the article according to the present disclosure, the relative areas of the see-through region(s) of lower porosity and the opaque, microporous region may be different in different embodiments. The see- through region(s) can make up at least 5, 10, 20, 25, 50, 75, or 90 percent of the visible area of the backsheet, tape backing, release tape, mechanical fastener, or decorative film, for example, described herein. For some patterns (e.g., a pattern of rhombuses or other geometric shapes), the opaque, microporous region may appear as strands separating the see-through regions. For other patterns, the see- through regions may appear more widely separated on a continuous, opaque, microporous background.

Some Embodiments of the Disclosure

In a first embodiment, the present disclosure provides an article comprising: a microporous thermoplastic film having first and second major surfaces, the microporous thermoplastic film comprising an opaque, microporous region and a see-through region of lower porosity having a pre-determined shape; and a first adhesive having a first color disposed on the second major surface of the microporous thermoplastic film, wherein a portion of the first adhesive is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

In a second embodiment, the present disclosure provides the article of the first embodiment, wherein the see-through region of lower porosity is included in a pattern of see-through regions of lower porosity.

In a third embodiment, the present disclosure provides the article of the first or second embodiment, wherein the see-through region of lower porosity is in the form of a number, symbol, picture, geometric shape, bar code, an alphabetical letter, or a combination thereof.

In a fourth embodiment, the present disclosure provides the article of any one of the first to third embodiments, wherein the microporous thermoplastic film comprises at least one of a beta-nucleating agent, a diluent, or a particulate cavitating agent, or at least one of a beta-nucleating agent or a diluent, or a beta-nucleating agent.

In a fifth embodiment, the present disclosure provides the article of the fourth embodiment, wherein the microporous thermoplastic film comprises a polyolefin, in some embodiments, polypropylene.

In a sixth embodiment, the present disclosure provides the article of any one of the first to fifth embodiments, wherein the microporous thermoplastic film comprises upstanding posts on the first major surface.

In a seventh embodiment, the present disclosure provides the article of any one of the first to sixth embodiments, wherein the article is a roll of tape, further comprising a release coating on the first major surface of the microporous thermoplastic film.

In an eighth embodiment, the present disclosure provides the article of any one of the first to seventh embodiments, wherein the first adhesive is a pressure sensitive adhesive.

In a ninth embodiment, the present disclosure provides the article of the eighth embodiment, wherein the pressure sensitive adhesive comprises an acrylic resin.

In a tenth embodiment, the present disclosure provides the article of the eighth embodiment, wherein the pressure sensitive adhesive comprises natural or synthetic rubber.

In an eleventh embodiment, the present disclosure provides the article of any one of the first to tenth embodiments, wherein the first adhesive is opaque.

In a twelfth embodiment, the present disclosure provides the article of any one of the first to tenth embodiments, wherein the first adhesive is transparent.

In a thirteenth embodiment, the present disclosure provides the article of any one of the first to twelfth embodiments, wherein the first adhesive has a color other than white. In a fourteenth embodiment, the present disclosure provides the article of any one of the first to thirteenth embodiments, further comprising a second adhesive having a second color other than the first color disposed on the second major surface of the microporous thermoplastic film, and wherein portions of both the first adhesive and the second adhesive are visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

In a fifteenth embodiment, the present disclosure provides the article of the fourteenth embodiment, wherein the second adhesive is a pressure-sensitive adhesive.

In a sixteenth embodiment, the present disclosure provides the article of the fifteenth embodiment, wherein the pressure sensitive adhesive comprises an acrylic resin.

In a seventeenth embodiment, the present disclosure provides the article of the fifteenth embodiment, wherein the pressure sensitive adhesive comprises natural or synthetic rubber.

In an eighteenth embodiment, the present disclosure provides the article of any one of the fourteenth to seventeenth embodiments, wherein the second adhesive is opaque.

In a nineteenth embodiment, the present disclosure provides the article of any one of the fourteenth to seventeenth embodiments, wherein the second adhesive is transparent.

In a twentieth embodiment, the present disclosure provides the article of any one of the fourteenth to nineteenth embodiments, wherein the second color is other than white.

In a twenty-first embodiment, the present disclosure provides the article of any one of the fourteenth to twentieth embodiments, further comprising a substrate, wherein the first adhesive and the second adhesive adhere the microporous thermoplastic film to the substrate.

In a twenty-second embodiment, the present disclosure provides the article of any one of the first to thirteenth embodiments, further comprising a substrate, wherein the first adhesive adheres the microporous thermoplastic film to the substrate.

In a twenty-third embodiment, the present disclosure provides the article of the twenty-first or twenty-second embodiment, wherein the article is a personal hygiene article, and wherein the substrate is a component of the personal hygiene article.

In a twenty-fourth embodiment, the present disclosure provides the article of the twenty-third embodiment, wherein the component of the personal hygiene comprises at least one of a backsheet, a topsheet, a fastening tab, a mechanical fastener, a release tape, or a disposal tape.

In a twenty-fifth embodiment, the present disclosure provides the article of the twenty-third embodiment, wherein the substrate is an absorbent core of the personal hygiene article, wherein the microporous thermoplastic film is a component of the backsheet of the personal hygiene article.

In a twenty-sixth embodiment, the present disclosure provides the article of the twenty-first or twenty-second embodiment, wherein the substrate is a wall, ceiling, window, or door, and wherein the microporous thermoplastic film is at least one of a decorative or protective film (e.g., wallpaper). In a twenty-seventh embodiment, the present disclosure provides the article of the twenty-sixth embodiment, wherein the substrate has at least one color, wherein the at least one color is visible through the see-through region of lower porosity of the microporous thermoplastic film.

In a twenty-eighth embodiment, the present disclosure provides the article of the twenty-seventh embodiment, wherein the substrate is coated with paint having the at least one color.

In a twenty-ninth embodiment, the present disclosure provides a process of making the article of any one of the twenty-first to twenty-eighth embodiments, the process comprising: at least one of spraying, printing, or coating the first adhesive and optionally the second adhesive onto the substrate; and adhering the microporous thermoplastic film to the substrate.

In a thirtieth embodiment, the present disclosure provides a process of making the article of any one of the first to twentieth embodiments, the process comprising: at least one of spraying, printing, or coating the first adhesive and optionally the second adhesive onto the second surface of the microporous thermoplastic film.

In a thirty-first embodiment, the present disclosure provides the process of the thirtieth embodiment, further comprising adhering the microporous thermoplastic film to a substrate.

In a thirty-second embodiment, the present disclosure provides the process of any one of the twenty-ninth to thirty-first embodiments, further comprising: providing the microporous thermoplastic film; and collapsing some pores in the microporous thermoplastic film to form the see-through region of lower porosity.

In a thirty-third embodiment, the present disclosure provides the process of the thirty-second embodiment, further comprising stretching a thermoplastic film comprising at least one of a beta- nucleating agent, a diluent, or a cavitating agent to form the microporous thermoplastic film.

In a thirty-fourth embodiment, the present disclosure provides the process of the thirty-third embodiment, wherein providing the microporous thermoplastic film comprises melt blending a crystallizable polymer and a diluent and cooling to a temperature at which the polymer crystallizes and phase separates from the diluent.

In a thirty-fifth embodiment, the present disclosure provides the process of the any one of the thirty-second to thirty-fourth embodiments, wherein collapsing some pores in the microporous thermoplastic film comprises heating the microporous thermoplastic film to collapse the pores to form the see-through region of lower porosity.

In a thirty-sixth embodiment, the present disclosure provides the process of the thirty-fifth embodiment, wherein heating the microporous thermoplastic film is carried out with a heated, patterned roller, with hot air, or with a laser.

In a thirty-seventh embodiment, the present disclosure provides the process of any one of the twenty-ninth to thirty-sixth embodiments, wherein the substrate is a component of a personal hygiene article, the process further comprising incorporating at least a portion of the article into the personal hygiene article.

Embodiments of the present disclosure have been described above and are further illustrated below by way of the following Examples, which are not to be construed in any way as imposing limitations upon the scope of the present disclosure.

EXAMPLE

Example 1

A film was prepared by feeding a stream of a polypropylene impact copolymer, obtained from the Dow Chemical Company, Midland, Mich., under the trade designation “DOW C700-35N POLYPROPYLENE RESIN” (98 weight %) and a beta nucleating master batch obtained from the Mayzo Corporation, Alpharetta, Ga., under the trade designation “MPM 1114” (2 weight %) through a 2-inch (5.08-cm) single screw extruder. The polymer density was reported by the manufacturer to be 0.902 g/cc as measured according to ASTM D972, and the melt flow index (MFI) was reported to be 35 (at 230 °C and under the load of 2.16 kg) as measured according to ASTM D 1238. The beta nucleating master batch was pelletized and contained a high-performance beta nucleant formulation dispersed in a polypropylene homopolymer resin. Seven barrel zones in the extruder were set at 176 °C, 170 °C, 180 °C, 190 °C, 200 °C, 218 °C, and 218 °C, respectively. The molten resin was then fed through a sheet die to a smooth chrome roll. The temperature of the die was set at 218 °C and the temperature of the roll was set at 90 °C. The screw speed was set at 80 rpm. The chrome roll was water-cooled to provide rapid quenching that maintained the orientation in the polymer. The line speed was set such that the film thickness was 100 micrometers. The film was then stretched in the machine direction by passing the web through two sets of rolls in which one roll was rotating faster than the other one. For each set of rolls, the bottom roll was a chrome roll, and the top roll was a rubber roll. For stretching, the temperature of each bottom chrome roll was set at 71 °C (160 °F) and that of each top rubber roll was set at 71 °C (160 °F). The draw ratio was 4: 1 in the machine direction.

The stretched sheet was then passed through a heated nip consisting of one wave-patterned roll at the bottom and a polished chrome roll on top. The pattern roll had the pattern shown in FIG. 1. The surface temperature of the patterned roll was set to 140 °C with a nip pressure of 1000 N. The nip gap was set to 0.005 cm. The patterned sheet after processing had alternative white, opaque regions and see- through regions in a wave pattern.

The patterned fdm was then sprayed on one major surface in a rectangular pattern with a green colored adhesive obtained from 3M Company, St. Paul, Minn., under the trade designation “Hi-Tack 71 Composite Spray Adhesive”. A different portion of the same major surface of the patterned fdm was sprayed in a rectangular pattern with a red colored adhesive obtained from 3M Company under the trade designation “3M Dry Layup Adhesive, Red 09091” such that the fdm has two different color patterns in the see-through regions when viewed from the major surface of the film opposite to the surface sprayed with adhesive.

This disclosure may take on various modifications and alterations without departing from its spirit and scope. Accordingly, this disclosure is not limited to the above-described embodiments but is to be controlled by the limitations set forth in the following claims and any equivalents thereof. This disclosure may be suitably practiced in the absence of any element not specifically disclosed herein.

Claims

What is claimed is:

1. An article comprising: a microporous thermoplastic film having first and second major surfaces, the microporous thermoplastic film comprising an opaque, microporous region and a see-through region of lower porosity having a pre-determined shape; and a first adhesive having a first color disposed on the second major surface of the microporous thermoplastic film, wherein a portion of the first adhesive is visible through the see-through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

2. The article of claim 1, wherein the see-through region of lower porosity is included in a pattern of see-through regions of lower porosity.

3. The article of claim 1 or 2, wherein the see-through region of lower porosity is in the form of a number, symbol, picture, geometric shape, bar code, an alphabetical letter, or a combination thereof.

4. The article of any one of claims 1 to 3, wherein the microporous thermoplastic film comprises at least one of a beta-nucleating agent or a diluent.

5. The article of any one of claims 1 to 4, wherein the microporous thermoplastic film comprises upstanding posts on the first major surface.

6. The article of any one of claims 1 to 5, wherein the article is a roll of tape, further comprising a release coating on the first major surface of the microporous thermoplastic film.

7. The article of any one of claims 1 to 6, wherein the first adhesive is a pressure sensitive adhesive.

8. The article of any one of claims 1 to 7, wherein the first adhesive is opaque.

9. The article of any one of claims 1 to 8, further comprising a second adhesive having a second color other than the first color disposed on the second major surface of the microporous thermoplastic film, and wherein portions of both the first adhesive and the second adhesive are visible through the see- through region of lower porosity when viewed from the first major surface of the microporous thermoplastic film.

10. The article of claim 9, further comprising a substrate, wherein the first adhesive and the second adhesive adhere the microporous thermoplastic film to the substrate.

11. The article of any one of claims 1 to 8, further comprising a substrate, wherein the first adhesive adheres the microporous thermoplastic film to the substrate.

12. The article of claim 10 or 11, wherein the article is a personal hygiene article, and wherein the substrate is a component of the personal hygiene article.

13. The article of claim 10 or 11, wherein the substrate is a wall, ceiling, window, or door, and wherein the microporous thermoplastic film is at least one of decorative film or a protective film.

14. A process of making the article of any one of claims 10 to 13, the process comprising: at least one of spraying, printing, or coating the first adhesive onto the substrate; and adhering the microporous thermoplastic film to the substrate.

15. A process of making the article of any one of claims 1 to 13, the process comprising: at least one of spraying, printing, or coating the first adhesive onto the second major surface of the microporous thermoplastic film; and optionally adhering the microporous thermoplastic film to a substrate.