Cross-Reference to Related Applications

This application claims the benefit of priority to U.S. Provisional Application No. 63/210,559, filed on June 15, 2021, which is incorporated herein by reference in its entirety.

Summary

The current disclosure relates to stretch removable adhesive articles, articles particularly suitable for medical uses, and constructions that include the stretch removable adhesive articles.

In some embodiments, the stretch removable articles comprise a multi-layer extensible backing substrate, where the multi-layer extensible backing substrate comprises at least three layers and a discontinuous inextensible layer comprising regions of inextensible material and gaps between the regions of inextensible material. The multi-layer extensible backing substrate comprises a first plastic skin layer with a first major surface and a second major surface, a core elastomeric layer with a first major surface and a second major surface, and a second plastic skin layer with a first major surface and a second major surface, where the core elastomeric layer is in contact with the second major surface of the first plastic skin layer and the first major surface of the second plastic skin layer. The discontinuous inextensible layer is adjacent to or disposed on the second major surface of the second plastic skin layer, and has a core thickness to skin thickness ratio of less than 10 to 1, a plastic deformation of at least 50%, an elongation of less than 600%, and a Fn Modulus of less than 20 N per inch width at 50% elongation.

In other embodiments, the stretch removable articles comprise a multi-layer extensible backing substrate, where the multi-layer extensible backing substrate comprises at least three layers and a continuous inextensible layer. The multi-layer extensible backing substrate comprises a first plastic skin layer with a first major surface and a second major surface, a core elastomeric layer with a first major surface and a second major surface, and a second plastic skin layer with a first major surface and a second major surface, where the core elastomeric layer is in contact with the second major surface of the first plastic skin layer and the first major surface of the second plastic skin layer. The continuous inextensible layer is sufficiently thin that upon application of a stretching force, the continuous inextensible layer breaks to form regions of inextensible material and gaps between the regions of inextensible material. The continuous inextensible layer is adjacent to or disposed on the second major surface of the second plastic skin layer, where the extensible substrate has a core thickness to skin thickness ratio of less than 10 to 1, has a plastic deformation of at least 50%, an elongation of less than 600%; and a Fn Modulus of less than 20 N per inch width at 50% elongation.

Also disclosed are constructions. In some embodiments, the constructions comprise a surface, a stretch removable article attached to the surface, and a device attached to the stretch releasable article. The stretch releasable articles are described above. Brief Description of the Drawings

The present application may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings.

Figure 1 is a cross sectional view of an embodiment of an article of this disclosure.

Figure 2A is a cross sectional view of an adhesive construction of this disclosure.

Figure 2B is a cross sectional view of the adhesive construction of Figure 2A after stretch removal.

Figure 3 is a cross sectional view of another embodiment of an article of this disclosure.

Figure 4 is a cross sectional view of another embodiment of an article of this disclosure.

Figure 5 is a top view of another embodiment of an article of this disclosure.

In the following description of the illustrated embodiments, reference is made to the accompanying drawings, in which is shown by way of illustration, various embodiments in which the disclosure may be practiced. It is to be understood that the embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure. The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

Detailed Description

Various medical devices are attached to a patient. For example, tubing, monitors, sensors, or catheters are secured to skin. To limit irritation, dislodgement, and potential exposure to infection, the medical devices should be securely attached to the patient. Adhesives and adhesive tapes are commonly used to secure devices to skin. Very strong adhesives can cause trauma to skin upon removal. A very gentle adhesive can be easily removed from the skin, but might not have sufficient strength to secure the medical device. Therefore, there is a need for medical adhesive articles that adhere strongly and yet are removable without causing skin damage or pain.

Among the recent developments is the use of stretch removability to permit removal of the adhesive article from the skin. In these articles, a film backing is used that has an extensible substrate with a securing adhesive that can secure to a surface, and a tab to stretch the extensible substrate to remove the adhesive from the underlying surface. Stretching the extensible substrate will release the securing adhesive from the underlying surface easily and without trauma. Therefore, a strong adhesive can be used.

This mechanism is known as “stretch release”. Stretch release tapes are known for use in securing items to surface, such as walls. For example, 3M COMMAND tape is a stretch release tape with a foam substrate coated on both surfaces with a strong adhesive. In PCT Publication 2021/064696 (US Patent Serial No. 62/910667 filed on October 4, 2019), such a stretch releasable medical tape article is described. When looking to secure a stretch removable tape to an underlying substrate that is conformable, such as skin, the extensible substrate should have a low modulus to minimize the force required to stretch and pull the extensible substrate. The extensible substrate should have low elongation to minimize the distance needed to stretch and pull the extensible substrate. Further, it is desirable that a majority of the deformation of the extensible substrate be plastic deformation and that its elastic deformation be minimized. Plastic deformation of the extensible substrate reduces the energy released upon the removal of stress, since the energy input to the extensible substrate is consumed by re-ordering the fdm morphology rather than being stored as potential energy in elastic structures. Less stored energy improves safety during the removal of devices held in place with an extensible substrate. The combination of low modulus and large degree of plastic deformation makes one-handed stretch and removal of the extensible substrate from the surface possible, without the hazard of the extensible substrate and an overlying device, if included, from being snapped painfully into the removing hand.

In PCT Publication 2021/064696, to achieve plastic deformation, the disclosed extensible substrate has a core and at least a first skin on one side of the core. In some embodiments, there is a first skin on a first side of the core and a second skin on the second, opposite, side of the core. Multilayer films designed for maximum strength often include an elastic layer forming the core sandwiched between two plastically-deformable layers forming the skin. To minimize the elasticity of the overall construction, the elastic content is minimized.

An additional complication involved in the use of stretch removable adhesive articles in medical applications, is that the adhesive articles to be removed from the skin frequently include devices, monitors, or other inextensible components. It can be difficult to identify an adhesive with sufficient adhesion to the inextensible component to ensure robust securement, but not so strongly that it fails to separate from the inextensible component during stretching of the multilayer film. An adhesive that will not separate from the component will prevent stretch removability.

In this disclosure, a stretch removable adhesive article is disclosed that includes a “sacrificial layer” located between an inextensible substrate and the extensible adhesive article. This sacrificial layer is either discontinuous or fragile such that when stretching forces are applied, the sacrificial layer separates to permit the stretch removability of the adhesive article. Thus, even if the adhesive between the sacrificial layer and the inextensible substrate does not stretch and release, the sacrificial layer releases and permits removal of the adhesive article from skin.

The term “adhesive” as used herein refers to polymeric compositions useful to adhere together two adherends. Examples of adhesives are pressure sensitive adhesives, heat activated adhesives, hot melt adhesives, and curable adhesives.

Pressure sensitive adhesive compositions 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 pressure sensitive adhesives are polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. Obtaining the proper balance of properties is not a simple process.

Heat activated adhesives are non-tacky at room temperature but become tacky and capable of bonding to a substrate at elevated temperatures. These adhesives usually have a Tg (glass transition temperature) or melting point (Tm) above room temperature. When the temperature is elevated above the Tg or Tm, the storage modulus usually decreases, and the adhesive becomes tacky.

Hot melt adhesives are thermoplastic materials that are solid and non-tacky at room temperature but upon heating melt and flow. The hot melt adhesive is applied in the molten state and forms a bond upon cooling to a solid state.

Curable adhesives, as the term implies, are adhesives that are curable. Curable adhesives are in many ways similar to hot melt adhesives, in that the adhesive is applied in the uncured (typically liquid) state and the adhesive bond forms upon curing. Unlike a hot melt adhesive, the cured adhesive bond is irreversible, whereas a hot melt bond can be reversed upon heating. Examples of curable adhesives are thermosetting adhesives and UV-curable adhesives.

The term “(meth)acrylate” refers to monomeric acrylic or methacrylic esters of alcohols. Acrylate and methacrylate monomers or oligomers are referred to collectively herein as "(meth)acrylates”. Materials referred to as “(meth)acrylate functional” are materials that contain one or more (meth)acrylate groups.

The terms “siloxane-based” as used herein refer to polymers or units of polymers that contain siloxane units. The terms silicone or siloxane are used interchangeably and refer to units with dialkyl or diaryl siloxane (-SiR20-) repeating units.

The terms "room temperature" and "ambient temperature" are used interchangeably to mean temperatures in the range of 20°C to 25°C.

The terms “Tg” and “glass transition temperature” are used interchangeably. If measured, Tg values are determined by Differential Scanning Calorimetry (DSC) at a scan rate of 10°C/minute, unless otherwise indicated. Typically, Tg values for copolymers are not measured but are calculated using the well-known Fox Equation, using the homopolymer Tg values provided by the monomer supplier, as is understood by one of skill in the art.

The term “adjacent” as used herein when referring to two layers means that the two layers are in proximity with one another with no intervening open space between them. They may be in direct contact with one another (e.g. laminated together) or there may be intervening layers.

The terms “polymer” and “macromolecule” are used herein consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeated subunits. As used herein, the term “macromolecule” is used to describe a group attached to a monomer that has multiple repeating units. The term “polymer” is used to describe the resultant material formed from a polymerization reaction.

The term “stretch removable” as used herein refers to adhesive articles that upon the application of a stretching force the adhesive strength decreases to permit the removal of the article from the substrate to which it is bonded.

The term “inextensible” as used herein refers to materials and layers that do not readily stretch upon the application of a stretching force. In some embodiments, inextensible layers have an elongation of 2% or less.

The term “extensible” refers to materials and layers that do readily stretch upon the application of a stretching force. In some embodiments, extensible layers have an elongation of 100% or more.

As mentioned above, in this disclosure, stretch removable adhesive articles are disclosed that are suitable for use with relatively rigid substrates such as devices, monitors, and the like. These stretch removable adhesive articles include a “sacrificial layer”. This sacrificial layer is either discontinuous or fragile such then when stretching forces are applied, the sacrificial layer separates to permit the stretch removability of the adhesive article. Thus, even if a strongly adhered, inextensible substrate is present that does not release, the sacrificial layer does release and permits removal of the adhesive article from skin

In some embodiments, the stretch removable article comprises a multi-layer extensible backing substrate, wherein the multi-layer extensible backing substrate comprises at least three layers and a discontinuous inextensible layer comprising regions of inextensible material and gaps between the regions of inextensible material. The multi-layer extensible backing substrate comprises at least a first plastic skin layer with a first major surface and a second major surface, a core elastomeric layer with a first major surface and a second major surface, and a second plastic skin layer with a first major surface and a second major surface, where the core elastomeric layer is in contact with the second major surface of the first plastic skin layer and the first major surface of the second plastic skin layer. The extensible substrate has a core thickness to skin thickness ratio of less than 10 to 1. The extensible substrate has a plastic deformation of at least 50%, an elongation of less than 600%; and a Fn Modulus of less than 20 N per inch width at 50% elongation. The discontinuous inextensible layer is adjacent to or disposed on the second major surface of the second plastic skin layer.

Examples of suitable multi-layer extensible backing substrates are described in US Patent Serial No. 62/910667. In the multi-layer extensible backing substrate, the core comprises an elastomeric material. Elastomeric means that the material exhibits at least some ability to return at least in part to its original shape or size after forces causing the deformation are removed. Examples of elastomeric material include elastomeric polymer, SEBS, SEPS, SIS, SBS, polyurethane, ethyl vinylacetate (EVA), ethyl methyl acrylate (EMA), linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), hydrogenated polypropylene, and combinations or blends thereof. The skin layers of the multi-layer extensible backing layer may be the same or different, typically they are the same. In some embodiments, the skin layers comprise a plastically deforming material. Plastic deformation means that the material undergoes a permanent change in shape or size when subjected to a stress exceeding a particular value (the yield value). Examples of plastically deforming materials include polypropylene, polyethylene, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polyurethane, ethyl vinylacetate (EVA), ethyl methyl acrylate (EMA), and combinations or blends thereof.

The core layer and skin layers can be bonded to one another using any suitable mechanism including, for example, coextruding the core and the skin layer(s), co-molding, extrusion coating, joining through an adhesive composition, joining under pressure, joining under heat, and combinations thereof.

The extensible substrate has a low Fn Modulus. The Fn Modulus is the force required to elongate the extensible substrate. The Fn Modulus is the force (F) required to elongate the test specimen a specified percent (n). Fn Modulus is usually recorded for elongation of 10%, 50%, and 100% for comparison of films.

Particularly suitable extensible substrates for application on skin has a F(50%) Modulus less than 20 N per 25.4 mm width. In some embodiments, the extensible substrate has a F(50%) Modulus less than 10 N per 25.4 mm width at 50% strain, or even a F(50%) Modulus less than 5 N per 25.4 mm width.

Elongation is the maximum percent of strain reached by a test sample to the point of breakage. The extensible substrate has a low elongation to minimize the distance needed to stretch the extensible substrate. A very high elongation means the extensible substrate will have a high distance it stretches before releasing from the surface. Excessive stretching is an inconvenience in settings where space is constrained. Modulus and elongation typically are measured under ambient conditions (25° C and 50% relative humidity) by a method based upon PSTC-31, ASTM D882 and D3759 Test Methods. The test can be performed on a constant rate of extension/tensile tester (such as an Instron, Zwick or equivalent). Typically, the extensible substrate has an elongation of at least 100%. In some embodiments, the elongation is much higher such as up to 300%, up to 500%, or even up to 600%.

It is desirable that a majority of the deformation of the extensible substrate is plastic deformation and that its elastic deformation is minimized. Elasticity is the ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed. In contrast, plasticity is the property of a solid body whereby it undergoes a permanent change in shape or size when subjected to a stress exceeding a particular value (the yield value). A highly elastic fdm may present a hazard during stretching to remove the fdm from a surface because as the fdm stretches, a significant amount of energy is stored in it. If the stretching film is not secured, upon the release of the film from the surface this energy will accelerate the film, and any attached device, toward the hand stretching the film, possibly resulting in injury or a broken device.

Plastic deformation is calculated using the original length of the extensible substrate (Lo), the length the extensible substrate reached under applied stress (Ls) and the length the extensible substrate relaxed to after the stress was removed (Lr).

% Plastic deformation = (Lr-Lo)/(Ls-Lo) ^c 100

For example, a one-inch (Lo) length of film stretched to five inches (Ls), which relaxes to a length of four inches (Lr) when the applied stress is removed, has a plastic deformation of 75%. ((4- 1 )/5 - 1 ) x 100).

Plastic deformation of the extensible substrate reduces the energy released upon the removal of stress, since the energy input to the extensible substrate is consumed by the re-ordering the film morphology rather than stored as potential energy in elastic structures. Less stored energy improves safety during the removal of devices held in place with an extensible substrate. The combination of low modulus and large degree of plastic deformation makes one-handed stretch and removal of the extensible substrate from the surface possible, without the hazard of the extensible substrate from being snapped painfully into the removing hand.

The extensible substrate has a plastic deformation of at least 50%. In some embodiments, the extensible substrate has a plastic deformation of at least 60%, or even at least 70%.

A wide variety of materials are suitable for use as the inextensible material of the discontinuous inextensible layer. Suitable materials include polyesters, polyurethanes, poly(meth)acrylates, polyolefins, or combinations thereof. Typically, the inextensible layer has an elongation of 2% or less.

In some embodiments, in order to form the discontinuous inextensible layer, at least one inextensible material is arrayed in a pattern. The pattern may comprise a one-dimensional pattern or a two-dimensional pattern. These patterns can be described by visualizing the surface of the layer by its x and y coordinates, where the axis is the width of the layer sometimes called the cross direction and the y axis is the length of the layer sometimes called the machine direction. Examples of one dimensional patterns include ones where there are gaps in the inextensible layer that are in the x axis or width direction and extend from one edge of the layer to the other. In examples of two- dimensional patterns, there are gaps not only in the x axis direction, but also in the y axis direction. It should be noted that gaps in the x axis direction need not be parallel to the x axis itself but may be angled at an angle from the x axis of from 0° to less than 90°. Similarly, the gaps in the y axis direction need not be parallel to the y axis itself but may be angled at an angle from the y axis of from 0° to less than 90°. Typically, the gaps are linear, but they need not be. Often it is convenient to form linear gaps, but non-linear gaps can also be used.

The simplest two-dimensional pattern is a two-dimensional grid pattern where the gaps in the x axis and the gaps in the y axis meet at a 90° angle. However, a wide range of two-dimensional patterns may be formed, including geometric designs, indicia, and the like. One particularly suitable two-dimensional pattern is a series of chevrons arranged such that the chevrons form arrows indicating the direction that the article is to be stretched to stretchably remove the article.

The discontinuous inextensible layer may be formed using a number of different techniques. In some embodiments, the discontinuous inextensible layer is formed as a discontinuous layer by extrusion of a polymeric material in a pattern, printing in a pattern, or coextrusion of a discontinuous layer on a continuous layer. In other embodiments, the discontinuous inextensible layer is formed as a continuous layer and discontinuities (gaps) are formed in the continuous layer. The gaps can be formed in the continuous layer by, for example, cutting or laser ablation.

In some embodiments, the discontinuous inextensible layer is formed by printing one or more patterns onto the second major surface of the second skin layer. The printing may be carried out by well-known printing techniques such as screen printing, inkjet printing, flexographic printing, stencil printing, and the like. This technique is particularly suitable for the formation of complex geometric patterns or indicia.

In some embodiments, the discontinuous inextensible layer is formed by disposing a continuous layer of polymeric material adjacent to the second major surface of the second skin layer and forming gaps in the continuous layer of polymeric material. As mentioned above, the formation of the gaps in the continuous layer of polymeric material can be achieved by, for example, cutting or laser ablation.

The stretch removable article may further comprise an adhesive layer adjacent to the first major surface of the first skin layer. This adhesive layer may be continuous or discontinuous and is described herein as a securing adhesive and is suitable for adhering the stretch removable article to human skin. Typically, the securing adhesive is a pressure sensitive adhesive. Among the suitable classes of pressure sensitive adhesives include rubber-based adhesives, siloxane -based adhesives, and (meth)acrylate-based adhesives. In some embodiments, the adhesive can include tackified rubber adhesives, such as natural rubber; olefins; siloxanes, such as silicone polyureas; synthetic rubber adhesives such as polyisoprene, polybutadiene, and styrene-isoprene-styrene, styrene- ethylenebutylene -styrene and styrene-butadiene-styrene block copolymers, and other synthetic elastomers; and tackified or untackified (meth)acrylate adhesives such as copolymers of isooctylacrylate and acrylic acid, which can be polymerized by radiation, solution, suspension, or emulsion techniques; polyurethanes; silicone block copolymers; and combinations of the above. The adhesive can be, for example, any of the adhesives described in PCT Patent Publication Nos. 2015/035556, 2015/035960, and US Patent Publication 2015/034104. In some embodiments, the adhesive includes additives such as tackifiers. Some exemplary tackifiers include polyterpene, terpene phenol, rosin esters, and/or rosin acids.

The stretch removable article may further comprise a tab at a perimeter portion of the extensible substrate. This tab is non-tacky and is designed to be grasped by a user to affect the stretch removal of the adhesive article. In some embodiments, the tab is a portion of an edge of the fdm backing that is free of adhesive. In other embodiments, the tab is a cover over the securing adhesive to create a portion of the first major surface that is free of a tacky adhesive. Therefore, a user can easily pull the extensible substrate from the underlying surface to remove the extensible substrate from the surface to which it is adhered.

In some embodiments, the stretch removable article further comprises a second tab on the opposite end of the article from the first tab. The second tab may be the same or different from the first tab.

In some embodiments, the stretch removable article further comprises a second adhesive layer adjacent to the discontinuous inextensible layer. This second adhesive layer is suitable for adhering a substrate such as device or monitor to the stretch removable article. The second adhesive layer may be a pressure sensitive adhesive or a curable adhesive such as a thermosetting or UV -curable adhesive. Pressure sensitive adhesive are described above. Suitable curable adhesives include (meth)acrylate adhesives, polyester adhesives, or epoxy adhesives.

Also disclosed herein are stretch removable articles that comprise a multi-layer extensible backing substrate and a continuous inextensible layer that is fragile such that upon the application of stretching force, the continuous inextensible layer breaks to form a discontinuous layer. Thus, upon the application of a stretching force the continuous inextensible layer behaves like a discontinuous inextensible layer.

Multi-layer extensible backing substrates are described above. In some embodiments, the multi-layer extensible backing substrate comprises at least three layers where the three layers comprise a first plastic skin layer with a first major surface and a second major surface, a core elastomeric layer with a first major surface and a second major surface, and a second plastic skin layer with a first major surface and a second major surface, where the core elastomeric layer is in contact with the second major surface of the first plastic skin layer and the first major surface of the second plastic skin layer. The extensible substrate has a core thickness to skin thickness ratio of less than 10 to 1; the extensible substrate has a plastic deformation of at least 50%, an elongation of less than 600%; and a Fn Modulus of less than 20 N per inch width at 50% elongation. The continuous inextensible layer is adjacent to or disposed on the second major surface of the second plastic skin layer.

The materials and descriptions of the core layer, skin layers, adhesive layers, and tabs are presented above. The same elements can also be used in embodiments that comprise a continuous inextensible layer.

The continuous inextensible layer is sufficiently thin that upon application of a stretching force, the continuous inextensible layer breaks to form regions of inextensible material and gaps between the regions of inextensible material. The continuous inextensible layer may be prepared from a variety of materials. In some embodiments the continuous inextensible layer comprises polyester, polyurethane, (meth)acrylate, polyolefin, or a combination thereof.

The continuous inextensible layer may have a variety of thicknesses. Typically, the continuous inextensible layer has a thickness of from 1 to 100 micrometers. In some embodiments, the continuous inextensible layer has a thickness of from 1 to 50 micrometers, 1 to 25 micrometers, or even 1 to 10 micrometers.

The continuous inextensible layer may be formed using a number of different techniques. In some embodiments, the continuous inextensible layer is formed by extrusion of a polymeric material or coextrusion of a continuous layer. In other embodiments, the continuous inextensible layer is formed by coating or printing.

Also disclosed are adhesive constructions. In some embodiments, the construction comprises a surface, a stretch removable article attached to the surface, and a device attached to the stretch releasable article. Typically, the surface comprises mammalian skin. The stretch removable articles are the articles described above, and the device is a medical device such as a monitor.

In some embodiments, the stretch releasable article comprises a multi-layer extensible backing substrate, a discontinuous inextensible layer, a first adhesive layer and a second adhesive layer. Each of these layers are describe above. In some embodiments, the multi-layer extensible backing substrate comprises at least three layers. The three layers comprise a first plastic skin layer with a first major surface and a second major surface, a core elastomeric layer with a first major surface and a second major surface, and a second plastic skin layer with a first major surface and a second major surface, where the core elastomeric layer is in contact with the second major surface of the first plastic skin layer and the first major surface of the second plastic skin layer. The discontinuous inextensible layer comprising regions of inextensible material and gaps between the regions of inextensible material, is adjacent to or disposed on the second major surface of the second plastic skin layer. A first adhesive layer is adjacent to the first major surface of the first skin layer, and is attached to the surface. A second adhesive layer is adjacent to the discontinuous inextensible layer, and the device is attached to the second adhesive layer.

The articles of this disclosure may be more fully understood by reference to the figures. Figure 1 shows a cross sectional view of article 100 with multilayer stretch releasable article 110 with layers 111, 112, and 113 with discontinuous layer 120 disposed on layer 113. Layers 111 and 113 are plastically deformable, layer 112 is elastically deformable, and discontinuous layer 120 is inelastic.

Figure 2A shows a cross sectional view of construction 200. Construction 200 has multilayer stretch releasable article 210 as shown in Figure 1 above with layers 211, 212, and 213, and discontinuous layer 220 disposed on layer 213. As above, layers 211 and 213 are plastically deformable, layer 212 is elastically deformable, and discontinuous layer 220 is inelastic. Non-tacky tabs 214 and 215 attached to layer 211. Article 240 is attached to discontinuous layer 220 by adhesive layer 250. Article 240 may be a wide range of articles, typically a relatively rigid article such as a monitor, sensor or the like. Substrate 260 is attached to layer 211 of article 210 by adhesive layer 270. Substrate 260 may be, for example, mammalian skin. Adhesive layers 250 and 270 may be the same or different, and may be pressure sensitive adhesives, heat activated adhesives, hot melt adhesives, or curable adhesives.

Figure 2B is construction 200 of figure 2A that has been stretched to permit stretch removal to form construction 200B. Construction 200B has the separated elements: substrate layer 260B; stretched article 210B with stretched layer 21 IB, 212B, and 213B, non-tacky tabs 214 and 215, stretched adhesive layer 270B, and some segments of discontinuous layer 220; and article 240 with attached adhesive layer 250 and segments of discontinuous layer 220. Adhesive layer 270B has also stretched along with article 210B permitting the stretch removal adhesive layer 270 from substrate layer 260. Portions of discontinuous layer 220 have remained adhered to layer 213B and have not stretched. Other portions of discontinuous layer 220 have remained adhered to adhesive layer 250 which is attached to article 240. This is but one method by which stretch removal can be carried out, in other embodiments, adhesive layer 250 may also become stretched permitting the stretch removal of article 240.

Figure 3 shows a cross sectional view of article 300 with multilayer stretch releasable article 310) with layers 311, 312, and 313 with discontinuous layer 320 disposed on layer 313 and discontinuous adhesive layer 380 in registration with discontinuous layer 320. As in the articles described above, layers 311 and 313 are plastically deformable, layer 312 is elastically deformable, and discontinuous layer 320 is inelastic. Discontinuous adhesive layer 380 may be a be pressure sensitive adhesive, heat activated adhesive, hot melt adhesive, or a curable adhesive.

Figure 4 shows a cross sectional view of article 400 with multilayer stretch releasable article 410 with layers 411, 412, and 413 with continuous layer 490 disposed on layer 413. Continuous layer 490 is a fragile layer that breaks upon application of stretching force.

Figure 5 shows a top view of an article showing discontinuous layer 520 onto which are printed on some of the discontinuous segments arrows 521 to indicate the directions in which the article is to be stretched to effect removal. A wide range of designs or indicia can be printed onto the discontinuous segments for decoration or for informational purposes.

Examples

These examples are merely for illustrative purposes only and are not meant to be limiting on the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, unless noted otherwise. The following abbreviations are used: cm = centimeters; nm = nanometers; mW = milliWatts; mJ = milliJoules. The terms “weight %”, “% by weight”, and “wt%” are used interchangeably. Table 1: Materials

Production of laminate films using a multi-layer extrusion line:

Seven-layer coextruded stretch-release films were produced using a seven-layer pancake stack die (Type LF-400 COEX 7-layer from Labtech Engineering, located in Samutprakam, Thailand). Airflow to the die was manually controlled to achieve a blow-up ratio of approximately 2:1. The bubble was subsequently collapsed approximately six feet (2 meters) above the die, traversed through rollers, slit on the edges to produce two independent films, each of which were then wound onto a 3 inch (7.5 cm) core. The feed materials were supplied by seven independent 0.75 inch (20 mm) diameter extruders (Labtech Scientific Single Screw Extruder Type LE20-30/C HA). Layers 1-7 were fed using polymer pellets and masterbatch compound blends as is known in the art. The process temperatures used in each of the seven extruders were Zone 1: 330°F (166 °C), Zone 2: 350°F (177 °C), Zone 3: 360°F (182 °C). The die temperature and adapter temperatures were 360°F (182 °C). Formulations for each example are given below.

Examples made by coextrusion of sacrificial layer. Layers 1-3 of examples 1 and 2 functioned as a carrier, enabling the low modulus stretch- release construction (layers 4-7) to be processed with standard film handling equipment.

Example 1 : Discontinuous Sacrificial Layer via Coextrusion

A discontinuous (striped) sacrificial layer was created by using a striped die plate in the extrusion of layer 7. The layer compositions are provided in Table 2. Following expansion of the bubble on the blown film line, the stripes and the gaps between them were both approximately 4 mm wide.

Following removal from the carrier, elongation of the stretch-release construction perpendicular to the stripes resulted in the separation of the stripes from layer 6 of the stretch-release construction.

Table 2: Layer compositions in Example 1.

Example 2: A coextruded seven-layer film having a continuous sacrificial layer was made via coextrusion using the materials provided in Table 3. A continuous, thin, fragile sacrificial layer was produced. Upon elongation either crossweb or downweb, layer 7 fractured and separated from layer 6

Table 3: Layer compositions in Example 2.

Example 3: A film laminate made by coating a sacrificial layer onto a stretch-release construction.

A stretch-release film was made with the layer composition provided in Table 4.

Table 4: Stretch-release film composition.

Sacrificial layer formulation and preparation.

The materials in the table below were mixed until homogeneous and then coated at roughly one mil thickness on layer 7 of the stretch-release construction. The formulation was deposited as stripes or beads using a needle and syringe onto the stretchable film. To cure, the deposited resin was exposed to 365 nm light (ThorLabs UV Processor CS2010) with approximate UVA intensity of 150mW/cm2 for 30 seconds for a total dose of approximately 4500 mJ/cm2, resulting in a cured stiff film.

Upon elongation of the stretch-release construction, the sacrificial layer separated from the stretch-release construction. Table 5: Composition of sacrificial layer.