Adhesives for wet or dry bonding

Abstract

The adhesive article includes a substrate and a hot melt processable pressure sensitive adhesive layer disposed on the substrate. The pressure sensitive adhesive layer is a (meth)acrylate-based polymer that is a cured reaction product of a mixture that includes a (meth)arylate monomer, which is either a branched (meth)acrylate having a total of 10 to 17 carbon atoms or a mixture of second alkyl (meth)acrylate isomers having a total of 8 to 18 carbon atoms, a non-acid functional polar monomer, an optional acid functional monomer, a crosslinking moiety, and an initiator. The pressure sensitive adhesive composition can be contained in a packaging material.

Description

Summary of the Invention

[0001] Disclosed herein are adhesive articles having good adhesion to wet and dry surfaces. Also disclosed herein are adhesive compositions, methods for preparing the adhesive compositions, and medical structures comprising the adhesive for bonding medical devices to mammalian skin.

[0002] Disclosed herein is an adhesive article comprising a substrate having a first major surface and a second major surface, and a hot melt processable pressure sensitive adhesive layer disposed on at least a portion of the first major surface of the substrate. The pressure sensitive adhesive layer comprises a (meth)acrylate-based polymer, the (meth)acrylate-based polymer comprising a curable reaction product of a mixture comprising 89.0-99.49 wt.% of at least one first (meth)acrylate monomer, 0.5-5.0 wt.% of a non-acid functional ethylenically unsaturated polar monomer, 0-1 wt.% of an acid functional ethylenically unsaturated monomer, 0.01-5 wt.% of at least one crosslinking moiety, and 0.01-1.0 parts by weight, based on the total weight of the curable components, of at least one initiator. The first (meth)acrylate monomer comprises a branched (meth)acrylate having a total of 10-17 carbon atoms, or a mixture of second alkyl (meth)acrylate isomers having a total of 8-18 carbon atoms. The adhesion of the adhesive article to a wet protein leather surface is at least 50% of its adhesion to the same dry protein leather surface.

[0003] Also disclosed is an adhesive composition comprising a packaging material and a pressure sensitive adhesive, the pressure sensitive adhesive being described above and contained within the packaging material. The packaged pressure sensitive adhesive is hot melt processable.

[0004] A method of forming an adhesive article includes providing a substrate having a first major surface and a second major surface, providing a packaged adhesive composition, placing the packaged adhesive composition in a hot melt mixing apparatus, hot melt mixing the packaged adhesive composition, and dispensing the hot melt mixed adhesive composition onto at least a portion of the second major surface of the substrate surface to form a pressure sensitive adhesive layer. The packaged adhesive composition is described above.

[0005] Also disclosed herein is a medical structure comprising a surface comprising mammalian skin and a medical article adhesively bonded to the surface, the medical article comprising a medical device and a pressure sensitive adhesive layer, the pressure sensitive adhesive layer being described above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] The use of adhesive products in the medical industry has been widespread for a long time and is increasing. However, while adhesives and adhesive articles have shown themselves to be very useful for medical applications, their use also presents problems. While many medical adhesive articles are applied directly to the wound area, a wide range of medical articles, such as tapes and drapes, do not apply to the wound area itself, but rather serve to aid in treatment, such as holding absorbent materials or medical devices in place on the skin. Examples of medical devices that are held in place by tape include tubes, catheters, ostomy appliances, sensors, and the like.

[0007] Medical adhesives have a variety of desirable properties. Among these are typical adhesive requirements such as sufficient peel adhesion and shear retention, flexibility to bend with the body, and removable without causing skin damage. Because human skin is a living tissue, the skin surface can be relatively dry at times, and can be moistened by sweating, and the skin surface is exposed to a wide range of external fluids, such as body fluids and cleaning fluids, making the skin changeable. Therefore, there is a need for medical adhesives that can adhere to a wide range of skin surfaces, including both wet and dry surfaces.

[0008] Disclosed herein is an adhesive article comprising a substrate having a first major surface and a second major surface, and a hot melt processable (meth)acrylate-based pressure sensitive adhesive layer disposed on at least a portion of the first major surface of the substrate. The substrate can be a polymer film, a tape backing, or a medical device. The pressure sensitive adhesive comprises a (meth)acrylate-based polymer and may include optional additives such as a tackifying resin. The (meth)acrylate-based polymer is prepared by polymerizing a reaction mixture. In some embodiments, the hot melt processable adhesive is present in a packaging material.

[0009] As used herein, the term "adhesive" refers to a polymeric composition that is useful for adhering two adherends together. An example of an adhesive is a pressure sensitive adhesive.

[0010] Pressure sensitive adhesive compositions are well known to those skilled in the art to have properties including: (1) strong and permanent tack, (2) adhesion with no more than finger pressure, (3) sufficient ability to hold on to a substrate, and (4) sufficient cohesive strength to remove cleanly from the substrate. Materials that have been found to perform well as pressure sensitive adhesives are polymers designed and formulated to exhibit the necessary viscoelastic properties, resulting in the desired balance of tack, peel adhesion, and shear holding power. Obtaining the proper balance of properties is not an easy process.

[0011] The term "(meth)acrylate" refers to monomeric acrylic or methacrylic acid esters of alcohols. Acrylate and methacrylate monomers or oligomers are collectively referred to herein as "(meth)acrylates." Materials referred to as "(meth)acrylate-based" are materials that contain one or more (meth)acrylates and may contain additional copolymerized free-radically polymerizable materials.

[0012] The terms "free radically polymerizable" and "ethylenically unsaturated" are used interchangeably and refer to a reactive group that contains a carbon-carbon double bond that can be polymerized via a free radical polymerization mechanism.

[0013] The term "branched" when used to describe alkyl (meth)acrylates refers to an alkyl group where there is no branch on the carbon immediately adjacent to the ester group, i.e., H2C=CR 1 -C(O)-O-CH2-R a In the formula, C(O) refers to a carbonyl group C=O, and the branch is R a This occurs in the second alkyl (meth)acrylate group, where there are two alkyl groups attached to the carbons directly adjacent to the ester group, i.e., H2C=CR 1 -C(O)-O-CR b R c in which C(O) refers to the carbonyl group C=O and R b and R c are each an alkyl group.

[0014] The terms "room temperature" and "ambient temperature" are used interchangeably to mean a temperature in the range of 20°C to 25°C.

[0015] The term "adjacent" as used herein when referring to two layers means that the two layers are close to each other with no intervening open space between them. They may be in direct contact with each other (e.g., laminated together) or there may be an intervening layer.

[0016] The terms "polymer" and "macromolecule" are used herein consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeating subunits. The term "macromolecule", as used herein, is used to describe a group attached to a monomer having multiple repeating units. The term "polymer" is used to describe the resulting material formed from a polymerization reaction.

[0017] The term "protein leather" is used herein according to its commonly understood meaning. Protein leather, also known as Pleather, is composed of protein powder along with resin to form flexible sheets. These sheets resemble leather in appearance and durability.

[0018] The term "alkyl" refers to a monovalent group that is a radical of an alkane, which is a saturated hydrocarbon. An alkyl can be straight chain, branched chain, cyclic, or a combination thereof and typically has 1 to 20 carbon atoms. In some embodiments, an alkyl group contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, ethylhexyl, n-dodecyl, 2-dodecyl, 3-dodecyl, 4-dodecyl, and 5-dodecyl.

[0019] Disclosed herein is an adhesive article comprising a substrate having a first major surface and a second major surface, and a hot-melt processable (meth)acrylate-based pressure-sensitive adhesive layer disposed on at least a portion of the first major surface of the substrate.

[0020] A wide range of substrates are suitable for the adhesive article of the present disclosure. Generally, the substrate is a substrate that is useful in medical applications. Examples of suitable substrates include polymeric films, tape backings, or medical devices. The substrate may be a monolithic or multi-layer structure. In a multi-layer structure, the substrate may have various coatings or layers adjacent to or present as the first or second surface of the substrate.

[0021] A wide range of polymeric film substrates are suitable, including release liners. A release liner is a sheet material having a low adhesion coating on at least one surface. The hot melt processable pressure sensitive adhesive of the present disclosure can be disposed on a release liner to produce an article comprising a layer of pressure sensitive adhesive on the release liner. This adhesive / release liner article can be used to prepare other adhesive / substrate articles by laminating the adhesive layer to a different substrate and then removing the release liner. This allows for the placement of the adhesive on substrates that are difficult to place hot melt processable pressure sensitive adhesive directly on, such as substrates that are heat sensitive. The adhesive / release liner article may also be used to attach a pressure sensitive adhesive layer to articles, such as electrodes, ostomy appliances, and the like. Typically, the film material is sufficiently rigid to provide support to the adhesive article. In addition to release liners, other suitable film layers include those that, when attached to an anatomical surface, can conform to the surface and stretch even if the surface moves. In some embodiments, the film material is a film made of elastomeric polyolefin, polyurethane, polyester, or polyether block amide.

[0022] In some embodiments, the substrate is a tape backing. Examples of suitable tape backings include breathable conformable backings. A wide range of breathable conformable backings are suitable for use in the articles of the present disclosure. Typically, breathable conformable backings include woven or knitted fabrics, nonwoven fabrics, foams, or plastics.

[0023] In some embodiments, the breathable compatible backing comprises a highly moisture vapor permeable film backing. Examples of such backings, methods of making such films, and methods of testing their permeability are described, for example, in U.S. Patents 3,645,835 and 4,595,001. Typically, such backings are porous materials.

[0024] Generally, the backing conforms to the anatomical surface. Thus, when the backing is applied to an anatomical surface, the backing conforms to the surface even if the surface moves. Generally, the backing also conforms to the anatomical joints of animals. When the joint is flexed and then returned to its unflexed position, the backing stretches to accommodate the flexion of the joint, but is sufficiently elastic to continue to conform to the joint when the joint is returned to its unflexed state.

[0025] Examples of particularly suitable backings can be found in U.S. Patent Nos. 5,088,483 and 5,160,315 and include elastomeric polyurethane, polyester, or polyether block amide films that have a desirable combination of properties including elasticity, high water vapor permeability, and transparency.

[0026] The article may include additional optional layers. In some embodiments, it may be desirable for a primer layer to be present between the substrate surface and the pressure-sensitive adhesive layer. In general, the primer layer includes a material commonly referred to as a "primer" or "adhesion promoter". Primers and adhesion promoters are materials that are applied as a thin coating on a surface to strongly adhere to the surface and provide a modified surface chemistry to the surface. Examples of suitable coating materials include polyamides, poly(meth)acrylates, chlorinated polyolefins, rubbers, chlorinated rubbers, polyurethanes, siloxanes, silanes, polyesters, epoxies, polycarbodiimides, phenolic resins, and combinations thereof. Typically, the article of the present disclosure does not require a primer layer. This is because when the hot melt processable pressure-sensitive adhesive is placed on the substrate surface, it tends to form a strong interaction with a wide range of substrate surfaces, making a primer unnecessary.

[0027] In some embodiments, it may be desirable for the second major surface of the substrate, i.e., the surface that is not coated with the adhesive structure, to have a low adhesion coating. This is especially true when the adhesive article is supplied in the form of a tape. Many tapes are supplied as rolls, with the adhesive layer contacting the non-adhesive "back" side of the backing when rolled up. Often, this non-adhesive surface of the backing has a low adhesion coating or release coating thereon to allow the roll to be unwound. These low adhesion coatings are often referred to as "low adhesion backsize" or LAB. Many factors control whether a LAB coating is necessary or desirable, including the nature of the adhesive, the composition and topography of the backing, and the desired use of the tape article.

[0028] The substrate layer can have a wide range of thicknesses. Some substrates, such as foam substrates, can be relatively thick, while other substrates, such as film substrates, can be relatively thin. In some embodiments, the thickness is at least 10 micrometers and up to 2 millimeters, in some embodiments, the thickness is at least 10 micrometers and up to 152 micrometers (6 mils), and in still other embodiments, the thickness is from 25 micrometers (1 mil) to up to 102 micrometers (4 mils). A wide range of intermediate thicknesses is also suitable.

[0029] In some embodiments, the substrate comprises a medical device. A wide range of medical devices are suitable, including devices intended to be worn for short or long periods of time. Examples include a variety of monitors, pumps, electrodes, sensors, and communication modules that are attached to a patient. Examples of such devices include RFID, insulin pumps, BME (biomedical electrodes), continuous glucose monitors, flash glucose monitors, etc.

[0030] The adhesive article also includes a hot-melt processable pressure-sensitive adhesive layer disposed on at least a portion of the first major surface of the substrate, the pressure-sensitive adhesive layer including a (meth)acrylate-based polymer and optional additives.

[0031] Disclosed herein are hot melt processable adhesive compositions. The term "hot melt processable" is not a process description or limitation, but rather a material description, and means that the adhesive composition can be hot melt processed, but does not necessarily mean that the composition has been hot melt processed.

[0032] In some embodiments, the (meth)acrylate based polymer is 89.0 to 99.49 wt. % of at least one first (meth)acrylate monomer; 0.5 to 5.0 weight percent of a non-acid functional ethylenically unsaturated polar monomer; 0-1 wt. % of an acid-functional ethylenically unsaturated monomer; 0.01-5 wt. % of at least one cross-linking moiety; and 0.01 to 1.0 parts by weight, based on the total weight of the hardenable components, of at least one initiator.

[0033] A reaction mixture is prepared using the desired composition reactive components, which are then polymerized to form a (meth)acrylate-based polymer. The reaction mixture includes at least a first (meth)acrylate monomer, a non-acid-functional ethylenically unsaturated polar monomer, and may optionally include an acid-functional ethylenically unsaturated monomer, a cross-linking moiety, and at least one initiator. In addition, the reaction mixture may include one or more optional components, as described below.

[0034] The first (meth)acrylate monomer comprises a branched (meth)acrylate having a total of 10 to 17 carbon atoms, or a mixture of second alkyl (meth)acrylate isomers having a total of 8 to 18 carbon atoms.

[0035] In an embodiment in which the first (meth)acrylate monomer comprises a branched alkyl (meth)acrylate having 10 to 17 carbon atoms, the branched alkyl (meth)acrylate can be represented by the general formula H2C=CR 1 -C(O)-O-CH2-R a where C(O) refers to the carbonyl group C=O and the branch is R a Particularly preferred is isodecyl acrylate.

[0036] In embodiments where the first (meth)acrylate monomer comprises a mixture of second alkyl (meth)acrylate isomers having a total of 8 to 18 carbon atoms. In some embodiments, the mixture of second alkyl (meth)acrylate isomers comprises a mixture of at least 5 isomers. In some embodiments, the first (meth)acrylate comprises a mixture of second alkyl (meth)acrylate isomers of formula (I).

[0037] [ka] In the formula, R 1 and R 2 are each independently C1 to C 10 R is a saturated linear alkyl group. 1 and R 2 The sum of the carbon numbers is 8 to 18, and R 3 is H or CH. In some embodiments, R 1 and R 2 are each independently C1 to C 10 is a saturated linear alkyl group, R 1 and R 2 The sum of the carbon numbers of R is 9 to 17. 1 and R 2 are each independently C1 to C 10 is a saturated linear alkyl group, R 1 and R 2 The sum of the carbon numbers is 9 to 13. The monomer mixture is described, for example, in US Pat. No. 9,102,774.

[0038] The first (meth)acrylate monomer or mixture of monomers is a major component of the reaction mixture comprising at least 89% and up to 99.49% by weight based on the weight of all reactive monomers. In some embodiments, the first (meth)acrylate is present in an amount of at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%.

[0039] The compositions used to form the pressure sensitive adhesive polymer may further include a polar monomer. As used herein, the term "polar monomer" excludes acid functionality and is referred to as a "non-acid functional ethylenically unsaturated polar monomer."

[0040] Representative examples of suitable such polar monomers include, but are not limited to, 2-hydroxyethyl (meth)acrylate; 4-hydroxybutyl (meth)acrylate; N-vinylpyrrolidone (NVP); N-vinylcaprolactam (NVC); acrylamide; mono- or di-N-alkyl substituted acrylamide; t-butylacrylamide; dimethylaminoethyl acrylamide; N-octylacrylamide; poly(alkoxyalkyl) (meth)acrylates including 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethoxyethyl (meth)acrylate, 2-methoxyethyl methacrylate, and polyethylene glycol mono(meth)acrylate; alkyl vinyl ethers including vinyl methyl ether; and mixtures thereof. Particularly suitable polar monomers include those selected from the group consisting of NVP (N-vinylpyrrolidone), NVC (N-vinylcaprolactam), acrylamide mono- or di-N-alkyl substituted acrylamide, t-butylacrylamide, dimethylaminoethylacrylamide or N-octylacrylamide, and mixtures thereof.

[0041] The non-acid functional ethylenically unsaturated polar monomer is present in an amount of at least 0.5% to 5% by weight based on the total weight of monomers. In some embodiments, the non-acid functional ethylenically unsaturated polar monomer is present in an amount of at least 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 4.5% by weight.

[0042] The reaction mixture may optionally include an acid functional monomer, and the acid functional group may be the acid itself, such as a carboxylic acid, or a salt thereof, such as an alkali metal carboxylate, in part. Useful acid functional monomers include, but are not limited to, those selected from ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphonic acids, and mixtures thereof. Examples of such compounds include those selected from acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, citraconic acid, maleic acid, oleic acid, β-carboxyethyl (meth)acrylate, 2-sulfoethyl methacrylate, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, vinylphosphonic acid, and mixtures thereof.

[0043] The acid monomer, when present, is up to 1 wt % based on the total weight of the monomers, hi some embodiments, the acid functional monomer is present in an amount up to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 wt %.

[0044] The reaction mixture also includes at least one cross-linking moiety. A wide variety of cross-linking moieties are suitable. In some embodiments, the cross-linking moiety is a photocrosslinker. In other embodiments, the cross-linking moiety is a multifunctional (meth)acrylate. In yet other embodiments, the cross-linking moiety is a combination of a photocrosslinker and a multifunctional (meth)acrylate.

[0045] The photocrosslinker is copolymerizable and has free radical polymerizable groups that copolymerize with the monomers mentioned above. The copolymerizable photocrosslinker also contains photosensitive groups that, when exposed to the proper wavelength of light, typically high intensity ultra-violet (UV) radiation, form free radicals that can form crosslinks in the polymer. When the (meth)acrylate-based polymer is formed by the use of a photoinitiator, the photocrosslinker is not activated by the same wavelength of light as the photoinitiator. In this way, the copolymerizable photocrosslinker is incorporated into the polymer and can be heat treated since the crosslinker is thermally stable and will remain intact until activated by the appropriate wavelength of light. This allows the copolymerizable photocrosslinker to be activated until the polymer is hot melt coated. In some embodiments, these crosslinkers are activated by UV light generated from an artificial light source such as a medium pressure mercury lamp or a UV black light.

[0046] Suitable photocrosslinkers include monoethylenically unsaturated aromatic ketone comonomers that do not contain ortho-aromatic hydroxyl groups, such as those described in U.S. Pat. No. 4,737,559 (Kellen et al.). Specific examples include para-acryloxybenzophenone (ABP), para-acryloxyethoxybenzophenone, para-N-(methylacryloxyethyl)-carbamoylethoxybenzophenone, para-acryloxyacetophenone, ortho-acrylamidoacetophenone, acrylated anthraquinone, etc. Particularly suitable is ABP para-acryloxybenzophenone, also known as 4-acryloxybenzophenone.

[0047] Another suitable type of cross-linking moiety is multifunctional (meth)acrylate.Examples of useful multifunctional (meth)acrylate include, but are not limited to, di(meth)acrylate, tri(meth)acrylate, and tetra(meth)acrylate, such as 1,6-hexanediol di(meth)acrylate, poly(ethylene glycol) di(meth)acrylate, polybutadiene di(meth)acrylate, polyurethane di(meth)acrylate, propoxylated glycerin tri(meth)acrylate, and mixtures thereof.Multifunctional (meth)acrylate cross-links (meth)acrylate polymer during polymerization process.

[0048] The cross-linking moieties, whether photocrosslinkers, multifunctional (meth)acrylates, or combinations thereof, are present in an amount of at least 0.01% and up to 5% by weight based on the total weight of all monomers, in some embodiments, the cross-linking moieties are present in an amount of at least 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 4.5% by weight.

[0049] The reaction mixture also includes at least one initiator. Typically, the initiator is a photoinitiator, meaning that the initiator is activated by light, typically ultraviolet (UV) light. Photoinitiators are well understood by those skilled in the art of (meth)acrylate polymerization. Examples of suitable free radical photoinitiators include DAROCURE 1173, DAROCURE 4265, IRGACURE 184, IRGACURE 651, IRGACURE 1173, IRGACURE 819, LUCIRIN TPO, LUCIRIN TPO-L, available from BASF (Charlotte, North Carolina). Photoinitiator DAROCURE 1173 is particularly suitable.

[0050] Generally, photoinitiators are used in amounts of 0.01 to 1 parts by weight, more typically 0.1 to 0.5 parts by weight, based on 100 parts by weight of total reactive components.

[0051] The reaction mixture may also contain various optional additives, so long as the additives do not adversely affect the polymerization reaction. One particularly suitable additive is a chain transfer agent. Examples of useful chain transfer agents include, but are not limited to, those selected from the group consisting of carbon tetrabromide, mercaptans, alcohols, and mixtures thereof. A particularly suitable chain transfer agent is IOTG (isooctylthioglycolate). Chain transfer agents and the use of chain transfer agents are well understood in the adhesives art.

[0052] The reaction mixture is polymerized to form a (meth)acrylate-based polymer. The pressure-sensitive adhesive layer of the adhesive article comprises the (meth)acrylate-based polymer and may also comprise additional additives as described below. Polymerization of the reaction mixture can be carried out using a variety of conventional free radical polymerization techniques, including solvent-based and solvent-free processes.

[0053] A typical solution polymerization process is carried out by adding the monomers, a suitable solvent, and an optional chain transfer agent to a reaction vessel, adding a free radical initiator, purging with nitrogen, and maintaining the reaction vessel at an elevated temperature, typically in the range of 40-100°C, for typically 1-20 hours, depending on the batch size and temperature, until the reaction is complete. Examples of solvents include methanol, tetrahydrofuran, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, toluene, xylene, and ethylene glycol alkyl ethers. These solvents can be used alone or as mixtures thereof.

[0054] Solvent-free polymerization methods can also be used to prepare the polymers, such as the continuous free radical polymerization methods described in U.S. Pat. Nos. 4,619,979 (Kotnour et al.) and 4,843,134 (Kotnour et al.), the essentially adiabatic polymerization methods using batch reactors described in U.S. Pat. No. 5,637,646 (Ellis), and the methods described for polymerizing packaged adhesive precursor compositions described in U.S. Pat. No. 5,804,610 (Hamer et al.).

[0055] The pressure-sensitive adhesive layer comprises a (meth)acrylate-based polymer and may also contain one or more conventional additives. Suitable additives include tackifiers, plasticizers, dyes, antioxidants, and UV stabilizers, so long as the additives do not adversely affect the adhesive properties of the adhesive layer.

[0056] The tackifier resin is particularly suitable for use in the pressure-sensitive adhesive layer of the adhesive article. Suitable tackifier resins include rosin and its derivatives (e.g., rosin esters); polyterpene and aromatic modified polyterpene resins; coumarone-indene resins; and hydrocarbon resins such as alpha-pinene-based resins, beta-pinene-based resins, limonene-based resins, aliphatic hydrocarbon-based resins, aromatic modified hydrocarbon-based resins, aromatic hydrocarbon resins, dicyclopentadiene-based resins, etc. In certain embodiments, the tackifier is a terpene resin, a hydrocarbon resin, a rosin resin, a petroleum resin, or a combination thereof. If desired, a combination of various tackifiers can be used. If desired, these tackifier resins can be hydrogenated to reduce their color contribution to the pressure-sensitive adhesive layer.

[0057] Tackifying resins, when used, are typically present in the pressure sensitive adhesive layer in an amount of from 2 to 25 parts tackifier per 100 parts (meth)acrylate-based polymer.

[0058] The adhesive article of the present disclosure has a wide range of desirable properties. Among the desirable properties is adhesion to both wet and dry surfaces. This property makes the adhesive article suitable for use on wet or dry skin. The adhesion of the adhesive article to wet or dry skin can be modeled in a variety of ways. In this disclosure, protein leather is used as a particularly suitable test surface. Protein leather refers to artificial leather (sometimes called pleather) that is composed of protein powder with resin to form flexible sheets. These sheets resemble leather in appearance and durability. The use of protein leather in testing samples is described in detail in the Examples section. One particularly suitable protein leather is Protein Leather PBZ13001 KAKI from IDEATEX Japan Co.

[0059] Current adhesive articles have an adhesion to a wet protein leather surface that is at least 50% of its adhesion to the same dry protein leather surface, in some embodiments, an adhesion to a wet protein leather surface that is at least 55%, at least 60%, at least 65%, or even at least 70% of its adhesion to the same dry protein leather surface.

[0060] In some embodiments, the adhesive article has an adhesion to a wet protein leather surface of at least 1 Newton / 25 millimeters. In some embodiments, the adhesive article has an adhesion to a wet protein leather surface of at least 1.5, at least 2, at least 2.5, or even at least 3.0 Newton / 25 millimeters.

[0061] The pressure-sensitive adhesive layer has a desirable elastic modulus. In many embodiments, the adhesive layer is hot-melt processed, and hot-melt processed pressure-sensitive adhesives often have a low elastic modulus that can result in many undesirable properties. In some embodiments, the pressure-sensitive adhesive has an elastic modulus of greater than 10,000 Pascals at 25°C, as measured by Dynamic Mechanical Analysis (DMA).

[0062] Another desirable property of current pressure-sensitive adhesive layers is the relative lack of orientation compared to that expected for hot-melt processed adhesive layers. It is well known in the adhesive art that hot-melt processing tends to produce oriented adhesive layers, for example, when compared to adhesive layers produced with solvent-based adhesives that are coated and dried. For example, it has been observed that hot-melt processing can cause birefringence in the adhesive layer in optical adhesives. In current medical articles, orientation of the pressure-sensitive adhesive layer is undesirable, especially for pressure-sensitive adhesives with modulus of elasticity greater than 10,000 Pascals, as discussed above. Orientation is undesirable because it can prevent the pressure-sensitive adhesive layer from wetting out a surface, especially a surface that is not smooth. In addition, stresses present in an oriented adhesive layer can, over time, cause the adhesive layer to curl (the edge of the adhesive layer lifts up against the adhesive surface and bends away from the adhesive surface) or other adhesive failure modes.

[0063] The amount of orientation present in an adhesive layer can be measured in a variety of different ways. In the Examples section, a shrinkage test is described that provides a method to characterize the orientation. Since an oriented adhesive layer has built-in stress, the oriented adhesive layer causes the article to shrink.

[0064] Adhesive compositions are also disclosed. These compositions can be used to form the pressure sensitive adhesive layer of the adhesive articles described above. The adhesive compositions include a packaging material and a pressure sensitive adhesive, the pressure sensitive adhesive contained within the packaging material, and the packaged pressure sensitive adhesive is hot melt processable. The pressure sensitive adhesive includes a (meth)acrylate polymer, the (meth)acrylate polymer being 89 to 99.49 wt. % of at least one first (meth)acrylate monomer; 0.5 to 5.0 weight percent of a non-acid functional ethylenically unsaturated polar monomer; 0-1 wt. % of an acid-functional ethylenically unsaturated monomer; 0.01-5 wt. % of at least one cross-linking moiety; and 0.01 to 1.0 parts by weight, based on the total weight of the curable components, of at least one initiator. The reactive components and properties of the pressure sensitive adhesive are described in detail above.

[0065] A method of forming an adhesive article is also disclosed. In some embodiments, the method includes providing a substrate having a first major surface and a second major surface, providing a packaged adhesive composition, placing the packaged adhesive composition in a hot melt mixing apparatus, hot melt mixing the packaged adhesive composition, and dispensing the hot melt mixed adhesive composition onto at least a portion of the first major surface of the substrate surface to form a pressure sensitive adhesive layer.

[0066] Suitable substrates are also described in detail above. Packaged adhesive compositions are also described in detail above. In some embodiments, placing the packaged adhesive composition into a hot melt mixing device further comprises adding a tackifier to the hot melt mixing device. Typically, the tackifier, if used, is added at a level of 2 to 25 parts by weight based on 100 parts (meth)acrylate-based polymer.

[0067] Also disclosed is a medical structure comprising a surface comprising mammalian skin and a medical article adhesively bonded to the surface. The medical article includes a medical device having a first major surface and a second major surface, the medical device having a pressure sensitive adhesive layer disposed on at least a portion of the second major surface of the medical device. The pressure sensitive adhesive is a hot melt processable (meth)acrylate adhesive as described above.

[0068] A wide range of medical devices are suitable, in some embodiments including a wide range of medical devices including monitors, pumps, electrodes, sensors, and communication modules, as described above. EXAMPLES

[0069] These examples are merely for illustrative purposes and are not meant to limit the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and the remainder of the specification are by weight unless otherwise noted. The following abbreviations are used: cm = centimeter, mm = millimeter, nm = nanometer, dm = decimeter, in = inch, RPM = revolutions per minute, Hz = Hertz, g = gram, kg = kilogram, lb = pound, oz = ounce, ml = milliliter, Pa = Pascal, μ-Nm = micrometer-newton meter, mW = milliwatt, mJ = millijoule, min = minute.

[0070] [Table 1]

[0071] Preparation of "100% Solids" or "Bulk" Polymers Used in the Examples A monomer mixture was prepared by blending reactive acrylic monomers, photoinitiator, and antioxidant in a jar. A magnetic stir bar was added to the mixture and the mixture was placed on a stir plate to form the curable composition. EVA film was heat sealed to form open-ended containers, each 18 cm by 5 cm. Approximately 24 grams of curable composition was filled into each container. Air was forced out of the open end and then sealed using a heat sealer (obtained under the trade name "MIDWEST PACIFIC IMPULSE SEALER" from JJ Elemer Corp., St. Louis, Missouri). The sealed EVA film containers with the curable composition sealed within were immersed in a constant temperature water bath at 16° C. and illuminated on both sides with ultraviolet light (365 nm, 4.5 mW / cm). 2 ) for 9 minutes to polymerize the curable composition. The polymerized samples were removed from the EVA film container for testing as described below.

[0072] Test Method Test method 1: Gel content measurement Approximately 24 grams of rectangular polymer sample was placed in the center of a pre-weighed rectangular mesh. The mesh was a stainless steel type 304 square weave wire cloth (obtained under the trade name "MCMASTER-CARR" from McMaster-Carr Co., Elmhurst, Ill.) of 150 mesh woven construction using 0.0026 inch (66 micrometer) wires and 0.0041 inch (104 micrometer) openings. The overhanging portion of the mesh was folded inward to cover and secure the sample inside the mesh. The folded mesh with encapsulated polymer was weighed and then immersed in about 8 oz. (about 240 ml) of ethyl acetate in a glass jar placed on a mechanical roller for 24 hours. The mesh with polymer was then removed from the jar, dried in an oven at 120° C. for 30 minutes, and reweighed to calculate the sample mass. The gelled insoluble portion of the polymer was calculated as gel weight percent ("gel wt %) using the following formula:

[0073]

number

[0074] Test method 2: Determination of the rheological profile DMA was used to measure the storage modulus, viscosity, and glass transition temperature of the adhesive precursor composition. A small sample of the adhesive precursor composition was transferred onto the bottom plate of a rheometer (obtained under the trade name "ARES G2 RHEOMETER" from TA Instruments, New Castle, Del.). The rheometer had a parallel 8 mm diameter top plate and a 25 mm bottom plate. The top plate of the rheometer was lowered onto the sample of adhesive precursor composition until the parallel plates were 1 mm apart. Excess material was trimmed from the edge of the 8 mm top plate. A temperature ramp test method was used to estimate the shear modulus, viscosity, and tan(δ) while subjecting the sample to oscillatory shear (frequency = 1 Hz) while simultaneously increasing the sample temperature continuously from -75°C to 150°C at a rate of 3°C / min. The strain amplitude was 0.05% at -75°C and increased with temperature to 3.6% iteratively as necessary to achieve a minimum torque of 10 μ-Nm. Storage modulus (G') was reported in Pa. Viscosity (i) of the adhesive precursor composition was reported in Pascal-seconds (Pa-s). Tan(δ) was calculated as the ratio of G" / G' (loss modulus / storage modulus). The temperature at which the Tan(δ) curve has a local peak was reported as the glass transition temperature ("Tg").

[0075] Test method 3: Shrinkage test A square of adhesive on a release liner measuring 10 cm x 10 cm was cut and folded parallel to the coating direction of the solvent-free adhesive. Gentle pressure was applied and the release liner was removed from the top. Now for the adhesive sample measuring 10 cm x 5 cm, the adhesive was folded again parallel to the coating direction while gentle pressure was applied to obtain a sample measuring 10 cm x 2.5 cm. The folding and pressure process was repeated one more time to obtain a final sample dimension of 10 cm (length) x 1.25 cm (width), which was defined as the unrelaxed length. The adhesive sample was then placed on a bed of talc and the adhesive in the talc was warmed to 65°C for 3 minutes. The length of the sample was then measured to obtain the "relaxed" sample length. The shrinkage of the sample was defined as ("unrelaxed length" - "relaxed length") / "relaxed length".

[0076] Test Method 4: Peel Adhesion to Dry VITRO-SKIN (Strips) The artificial skin substrate was obtained from IMS Inc. (Portland, Maine) under the trade name VITRO-SKIN (this material is formulated as supplied to mimic the topography, pH, critical surface tension, etc., of human skin). Dry adhesion to VITRO-SKIN was evaluated using strips of foam tape. Approximately 2-inch wide by 6-inch long (5×15 cm) pieces of VITRO-SKIN were cut and placed on a stainless steel plate using double-sided tape. Samples for dry skin adhesion testing were prepared in the form of adhesive-coated foam tape. Approximately 2-inch wide by 6-inch long (5×15 cm) pieces of masking tape were applied to the backing of the foam tape to reinforce the foam and prevent it from stretching. Approximately 1-inch wide by 6-inch long (2.5×15 cm) samples were then cut from the foam tape reinforced by the masking tape. The foam tape test samples were adhered to the VITRO-SKIN on a stainless steel plate with two passes (under and back) of a 4.5 lb (2 kg) roller. The average force to remove the foam tape from the VITRO-SKIN at 180 degrees was then determined using a Zwick instrument at a test speed of 12 in / min (30 cm / min).

[0077] TEST METHOD 5: PEEL ADHERENCE TO MOIST VITRO-SKIN (STRIPS) The artificial skin substrate was obtained from IMS Inc. (Portland, Maine) under the trade name VITRO-SKIN (this material is formulated as supplied to mimic the topography, pH, critical surface tension, etc., of human skin). The artificial sweat solution was created to mimic the properties of human sweat. The first component (artificial sebum) was a mixture of 5.5 g olive oil, 2.5 g oleic acid, and 2.0 g squalene. The second component was a mixture of 3.75 g sodium chloride, 0.75 g urea, and 0.75 g lactic acid. The second component was diluted to 750 mL with water and the pH was adjusted to 6.5 with NH4OH. 0.375 g of the first component was then thoroughly mixed with 750 ml of the second component to create the artificial sweat.

[0078] Wet adhesion to VITRO-SKIN was evaluated using strips of foam tape. Pieces of artificial skin approximately 2 inches wide by 6 inches long were cut and placed on a stainless steel plate using double-sided sticky tape. The artificial sweat solution was sprayed five times from a small spray bottle onto the artificial skin substrate.

[0079] Samples for wet skin adhesion testing were prepared in the form of adhesive-coated foam tape. A piece of masking tape approximately 2 inches wide by 6 inches long was applied to the backing of the foam tape to reinforce the foam and prevent it from stretching. Samples approximately 1 inch wide by 6 inches long (2.5 x 15 cm) were then cut from the masking tape-reinforced foam tape. The foam tape test samples were adhered to the VITRO-SKIN moistened with artificial sweat solution on a stainless steel plate by passing it twice (down and back) with a 4.5 lb (2 kg) roller. The test sample was allowed to dwell on the moist artificial skin for 2 minutes.

[0080] The average force to remove the foam tape from the wet VITRO-SKIN at 180 degrees was then determined using a Zwick instrument at a test speed of 12 inches / minute (30 cm / minute).

[0081] Test method 6: Tensile force against wet protein leather (electrode) The roll of adhesive was converted to a 3M 2560 electrode form factor following standard manufacturing practices used to prepare commercial electrodes. Wet substrate samples were prepared by cutting 65mm x 120mm sections of protein leather PBZ13001 KAKI (obtained from IDEATEX Japan Co.Ltd.) and immersing them in a bath of synthetic sweat containing 0.5% w / v synthetic sebum for approximately 30 minutes. The samples were removed from the bath and sprayed five times with sweat solution containing 0.5% w / v synthetic sebum using a 4oz spray bottle (Uline Model#S-20078). The electrode samples were hand-attached to the protein leather substrate and immediately thereafter a 275g weight was placed on top of the electrode for 5 seconds. A sample dwell time of 1 minute was used before the stud was connected to the electrode lead and pulled on the IMASS at 90 inches / minute until failure. The peak kinetic forces of the five samples were measured, averaged, and recorded.

[0082] Test Method 7: Peel Adhesion to Dry Protein Leather (Strips) A 25mm x 125mm tape sample was laminated on a 30mm x 125mm protein leather PBZ13001 KAKI (obtained from IDEATEX Japan Co. Ltd.) using a 2kg roller. The attached tape was removed by T-peel at a test speed of 150mm / min (for hot melt) or 300mm / min (for solvent) using TENSILON (A&D company Ltd.) (for hot melt) or SP-2100 (IMASS) (for solvent), and then the average peel force at the time of removal was measured.

[0083] Test Method 8: Peel Adhesion to Wet Protein Leather (Strips) The synthetic sweat dispersion was sprayed onto protein leather PBZ13001 KAKI (obtained from IDEATEX Japan Co. Ltd.) and allowed to dwell for 20-40 minutes. After wiping the protein leather, the synthetic sweat dispersion was sprayed again (5 sprays). The T-peel adhesion was then measured by repeating the procedure described in Test Method 7.

[0084] * Synthetic Sweat Dispersion: A synthetic sweat dispersion was used for the Wet Adhesion test and was prepared by mixing the following ingredients:

[0085] Synthetic sweat dispersion: 750ml synthetic sweat + 0.75g synthetic sebum

[0086] [Table 2]

[0087] Examples 1-3 and Comparative Example 1: Preparation and Analysis of Alkyl Acrylate Adhesive Compositions For each example, the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" was followed, using the amounts (parts by weight based on the total weight of IOA, Isomer Mixture A, Isomer Mixture B, and AA) listed in Table 1 to provide three examples (Examples 1-3).

[0088] [Table 3]

[0089] The gel content was measured for each of Examples 1 to 3. The results are summarized in Table 2.

[0090] [Table 4]

[0091] A sample of material from each example in Table 1 was compounded in a twin screw extruder at 160°C for 3 minutes. The resulting hot melt was coated onto a silicone release liner using a drop die. The die and extruder extrusion temperature was maintained at 160°C. The extruded sample was coated at a thickness of 3 mils (76 micrometers). A UV melt lamp and H bulb were then used to coat the extruded sample at 50 mJ / cm. 2 The samples were cured with UV-C radiation at 1000 nm and then hand laminated using a 5 lb (2.2 kg) hand roller onto 0.0625 inch thick EVA foam obtained from Sekesui Voltek under the trade name EO Volaro.

[0092] Comparative Example 1 was commercially prepared in-house at 3M using standard procedures and was used on 3M RED DOT adhesive.

[0093] Comparative Example 1 and Examples 1-3 were tested by measuring adhesion to VITRO-SKIN under both dry and wet conditions according to Test Methods 4 and 5. The results are summarized in Table 3.

[0094] [Table 5]

[0095] Examples 4-10: Preparation and Analysis of Polar Comonomer Adhesive Compositions For each example, the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" was followed, using the amounts (parts by weight based on the total weight of Isomer Mixture B, AA, and NVP) listed in Table 4 to provide seven examples (Examples 4-10).

[0096] [Table 6]

[0097] A sample of material from each example in Table 1 was compounded in a twin screw extruder at 160°C for 3 minutes. The resulting hot melt was coated onto a silicone release liner using a drop die. The die and extruder extrusion temperature was maintained at 160°C. The extruded sample was coated to a thickness of 3 mils (76 micrometers). A portion of the sample was then coated using a UV melt lamp and H bulb at 50 mJ / cm. 2 The sample was then hand laminated using a 5 lb (2.2 kg) hand roller onto 0.0625 inch thick EVA foam obtained from Sekesui Voltek under the trade name EO Volaro.

[0098] Comparative Example 1 was commercially prepared in-house at 3M using standard procedures and was used on 3M RED DOT adhesive.

[0099] Comparative Example 1 and Examples 1-3 were tested by measuring adhesion to VITRO-SKIN under both dry and wet conditions according to Test Methods 4 and 5 and are summarized in Table 5.

[0100] [Table 7]

[0101] Examples 11-12: Preparation and Analysis of Adhesive Compositions Containing Acidic and Basic Comonomers For each example, the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" was followed, using the amounts (parts by weight based on the total weight of Isomer Mixture B, AA, and NVP) listed in Table 6 to provide two examples (Examples 11-12).

[0102] [Table 8]

[0103] Samples of material from each example in Table 3 were compounded in a Bonnot extruder from Bonnot Company at 275°F (135°C) and a screw speed of 30 rpm. The heated samples were pumped into a twin screw extruder at a temperature of 320°F (160°C) and a screw speed of 200 rpm. The resulting hot melt was coated onto a silicone release liner using a rod coater die. The die and extruder extrusion temperature was maintained at 320°F (160°C). The extruded samples were coated at a thickness of 3 mils (76 micrometers). The samples were then coated at 60 mJ / cm using a UV melt lamp and H bulb. 2 The sample was then covered with EVA foam and wound into a roll.

[0104] The roll of adhesive was converted into an electrode form factor using standard manufacturing practices used to prepare commercial electrodes.

[0105] Examples 11-12 were tested by measuring adhesion to protein leather under wet conditions according to Test Method 8 and are summarized in Table 7. The samples were also evaluated for gel content according to Test Method 1.

[0106] [Table 9]

[0107] Examples 13-15: Preparation and Analysis of Adhesive Compositions Containing Acidic and Basic Comonomers For each example, three additional examples (Examples 13-15) were provided following the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" using the amounts (parts by weight based on the total weight of Isomer Mixture B, AA, and NVP) listed in Table 8.

[0108] [Table 10]

[0109] Samples of Examples 12, 13, or 14 from each example were compounded in a single screw extruder at 150° C. for 3 minutes at 300 rpm. The resulting hot melt was coated onto a silicone release liner using a drop die. The die and extruder extrusion temperature was maintained at 150° C. The extruded samples were coated at a thickness of 3 mils (76 micrometers). A portion of the sample was then coated using a UV melt lamp and H bulb at 60 mJ / cm. 2 The sample was then hand laminated using a 5 lb (2.2 kg) hand roller onto 0.0625 inch thick EVA foam obtained from Sekesui Voltek under the trade name EO Volaro.

[0110] Examples 12-14 were tested by measuring adhesion to protein leather under dry and wet conditions according to Test Methods 7 and 8 and are summarized in Table 9.

[0111] [Table 11]

[0112] Examples 15 to 17: Preparation of adhesive compositions containing tackifiers For each example, three additional examples (Examples 15-17) were provided following the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" using the amounts (parts by weight based on the total weight of Isomer Mixture B, AA, and NVP) listed in Table 8.

[0113] Adhesive samples were compounded with 10 parts by weight of P125 tackifier and compounded in a twin screw extruder at 320°F (160°C) in a Dynamelt C feeder. The resulting hot melt was processed at 248°F (120°C) and coated onto a silicone release liner using a drop die. The die and extruder extrusion temperature was maintained at 320°F. The extruded samples were coated to the thicknesses shown in Table 10. A UV melt lamp and H bulb were then used to coat the samples at 55 mJ / cm. 2 The samples were cured with UV-C radiation of 0.0625 inches in thickness and then wrapped in a roll of EVA foam obtained from Sekesui Voltek under the trade name EO Volaro.

[0114] [Table 12]

[0115] Examples 15-17 were tested by measuring adhesion to protein leather under dry and wet conditions according to Test Methods 7 and 8 and are summarized in Table 11.

[0116] [Table 13]

[0117] Examples 18-19: Preparation of adhesive compositions containing tackifiers For each example, three additional examples (Examples 18-19) were provided following the general procedure for "Preparation of '100% Solids' or 'Bulk' Polymer" using the amounts (parts by weight based on the total weight of Isomer Mixture B, AA, and NVP) listed in Table 8.

[0118] [Table 14]

[0119] Samples of material from each example in Table 3 were compounded in a Bonnot extruder from Bonnot Company at 275°F (135°C) and a screw speed of 30 rpm. The heated samples were pumped into a twin screw extruder at a temperature of 320°F (160°C) and a screw speed of 200 rpm. The resulting hot melt was coated onto a silicone release liner using a rod coater die. The die and extruder extrusion temperature was maintained at 320°F (160°C). The extruded samples were coated at a thickness of 3 mils (76 micrometers). The samples were then coated at 50 mJ / cm using a UV melt lamp and H bulb. 2 The sample was then covered with EVA foam and wound into a roll.

[0120] The roll of adhesive was converted into an electrode form factor using standard manufacturing practices used to prepare commercial electrodes.

[0121] [Table 15]

[0122] Example 12, Example 15, and Comparative Example 1: Rheological physical property tests Examples 12 and 15 were compounded in a Bonnot Company Bonnot extruder at 275°F (135°C) and a screw speed of 30 rpm. The heated samples were pumped into a twin screw extruder at a temperature of 320°F (160°C) and a screw speed of 200 rpm. The resulting hot melt was coated onto a silicone release liner using a rod coater die. The die and extruder extrusion temperature was maintained at 320°F (160°C). The extruded samples were coated at a thickness of 3 mils (76 micrometers). The samples were then optionally coated with 50 mJ / cm using a UV melt lamp and H bulb. 2The samples were then evaluated according to Test Method 2. Comparative Example 1 was taken from typical manufacturing conditions and evaluated according to Test Method 2.

[0123] [Table 16]

Claims

1. 1. An adhesive article comprising: a substrate having a first major surface and a second major surface; a hot-melt processable pressure-sensitive adhesive layer disposed on at least a portion of the first major surface of the substrate, the pressure-sensitive adhesive layer comprising a (meth)acrylate-based polymer, the (meth)acrylate-based polymer comprising: 89.0 to 99.49 wt. % of at least one first (meth)acrylate monomer; 0.5 to 5.0 weight percent of a non-acid functional ethylenically unsaturated polar monomer; 0-1 wt % of an acid-functional ethylenically unsaturated monomer; 0.01 to 5 wt. % of at least one cross-linking moiety; and 0.01 to 1.0 parts by weight, based on the total weight of the curable components, of at least one initiator; An adhesive article wherein the first (meth)acrylate monomer comprises a branched (meth)acrylate having a total of 10 to 17 carbon atoms or a mixture of second alkyl (meth)acrylate isomers having a total of 8 to 18 carbon atoms, and wherein the adhesive article has an adhesion to a wet protein leather surface that is at least 50% of its adhesion to the same dry protein leather surface.

2. the first (meth)acrylate comprises a mixture of second alkyl (meth)acrylate isomers of formula (I); 【Chemical 1】 During the ceremony, R １ and R ２ However, each independently, C １ ~C １０ is a saturated linear alkyl group of the formula R １ and R ２ The sum of the carbon numbers is 8 to 18, R ３ is H or CH ３ 10. The adhesive article of claim 1 wherein:

3. 3. The adhesive article of claim 2, wherein said second mixture of alkyl (meth)acrylate isomers comprises a mixture of at least five isomers.

4. R １ and R ２ However, each independently, C １ ~C １０ is a saturated linear alkyl; R １ and R ２ The adhesive article of claim 2, wherein the sum of the carbon numbers of is 9 to 17.

5. R １ and R ２ However, each independently, C １ ~C １０ is a saturated linear alkyl; R １ and R ２ The adhesive article of claim 2, wherein the sum of the carbon numbers of is 9 to 13.

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