Moisture permeable hot melt processable medical adhesive

Abstract

An article includes a substrate and a layer disposed on the substrate, the layer being at least one hot melt processable pressure sensitive adhesive that has been coated and photo-crosslinked. The adhesive is a copolymer based on a (meth) acrylate, the (meth) acrylate-based copolymer is a first (meth) acrylate monomer containing an alkyl, alkenyl or aryl group having from 4 to 20 carbon atoms, a second (meth) acrylate monomer containing an alkylene oxide group terminated with an alkyl group, a copolymerizable reinforcing monomer, and a third (meth) acrylate monomer containing an alkylene oxide group terminated with an alkylene group. A reaction product of a reaction mixture of a copolymerizable photocrosslinker and an initiator.

Description

SUMMARY OF THE INVENTION

[0001] The present disclosure relates to adhesive compositions that are photocrosslinkable and hot melt processable pressure sensitive adhesives. In particular, articles containing the adhesive compositions are disclosed.

[0002] In some embodiments, the article includes a substrate and a layer disposed on at least a portion of the substrate, the layer comprising at least one hot melt processable pressure sensitive adhesive that has been coated and photocrosslinked. The at least one hot melt processable pressure sensitive adhesive comprises a (meth)acrylate-based copolymer that is the reaction product of a reaction mixture comprising at least one first (meth)acrylate monomer of Formula I:

[0003] CH2=CR 1 -(CO)-OR 2

[0004] Formula I

[0005] wherein R 1 is hydrogen or a methyl group; and R 2 is an alkyl, alkenyl, or aryl group containing from 4 to 20 carbon atoms; and at least one second (meth)acrylate monomer of Formula II:

[0006] CH2=CR 1 -(CO)-OR 3

[0007] Formula II

[0008] wherein R 1 is hydrogen or a methyl group; and R 3 is an epoxyalkyl group capped with an alkyl group; at least one copolymerizable enhancing monomer; at least one copolymerizable photocrosslinker; and at least one initiator. DETAILED DESCRIPTION

[0009] The use of adhesive products in the medical industry has a long history and is increasing. However, while adhesives and adhesive articles have shown themselves to be very useful for medical applications, there are also problems with the use of adhesives and adhesive articles. In particular, the desired adhesive properties are often contradictory. For example, it is desirable for the adhesive to have high adhesion to a variety of surfaces, including human skin, and it is also desirable for the adhesive to be removable without damaging the skin. In addition, medical articles are worn for longer periods of time, require maintenance of adhesion, and also need to be removable without damaging the skin or leaving residues.

[0010] Another need for medical adhesives is to make the adhesive more hydrophilic to contribute to the moisture vapor transmission rate (MVTR) characteristic for long-term wear. A variety of medical articles and devices are designed to adhere to the skin for an extended period of time. Current adhesive systems have difficulty remaining adhered to the skin for an extended period of time because they are subject to moisture loading, that is, moisture trapped between the skin and the adhesive layer, because the adhesive has an insufficient MVTR, which results in "float off" of the system. MVTR is a measure of the amount of water vapor passing through a substance or barrier. Since sweating occurs naturally on the skin, if the MVTR of a material or adhesive system is low, this can lead to moisture accumulation between the skin and the adhesive, which can cause the adhesive to "float off" or peel and can also promote other harmful effects, such as bacterial growth and skin irritation. Therefore, much work has focused on the development of adhesive systems with high MVTR. Typically, adhesives are designed to be hydrophilic so that moisture from the skin will pass through the adhesive layer and not accumulate at the skin / adhesive interface. Since adhesives are typically hydrocarbon-rich and thus non-polar and hydrophobic, one way to make the adhesive more hydrophilic is to add a hydrophilic plasticizer. Typically, these plasticizers are polyalkylene oxide-based plasticizers. The drawback of this method is that since the plasticizers are free materials, they can migrate to the surface of the adhesive composition and remain as residues when the adhesive is removed.

[0011] Another trend in the adhesive field is to prepare adhesives without using solvents. There are various environmental and other reasons for eliminating solvents in the preparation of adhesive articles, but it can be difficult to manufacture adhesives (such as (meth)acrylate-based adhesives) without using solvents. The methods developed for preparing and coating adhesive systems are 100% solid systems, such as pressure-sensitive adhesives that can be hot melt processed. Difficulties have arisen when solvent processing is replaced by hot melt processing. It is generally difficult to replicate the characteristics of solvent-delivered adhesive layers with a hot melt delivery system.

[0012] Thus, among the desired and often conflicting characteristics required for medical adhesives are: high enough adhesion to adhere to the skin without causing skin damage or leaving residues upon removal; high enough cohesive strength to be useful; high MVTR for long-term wearability; and being hot melt processable, thus eliminating the need to use solvents.

[0013] The present disclosure relates to adhesive compositions and articles containing such adhesive compositions, wherein the adhesives are (meth)acrylate-based and contain monomers having alkyl-capped polyoxyalkylene groups. These groups contribute to providing a high MVTR, but because they are part of the polymer matrix, they cannot migrate freely to the surface and transfer as residues, as is the case with added plasticizers. The adhesives are desirable wet adhesives because they adhere to both wet and dry skin.

[0014] As used herein, the term "adhesive" refers to a polymer composition that can be used to attach two adherends together. Examples of adhesives are pressure-sensitive adhesives.

[0015] Pressure-sensitive adhesive compositions are well known to those of ordinary skill in the art and have the following characteristics: (1) strong and persistent tack; (2) adhesion that does not exceed finger pressure; (3) sufficient ability to remain on the adherend; and (4) sufficient cohesive strength to be cleanly removed from the adherend. Materials that function well as pressure-sensitive adhesives have been found to be polymers that are designed and formulated to exhibit the necessary viscoelastic properties that achieve the desired balance of tack, peel adhesion, and shear retention. Obtaining the proper balance of properties is not a simple process.

[0016] As used herein, the term "wet adhesive" refers to a material that exhibits pressure-sensitive adhesive properties when adhered to at least one wet surface (typically, both wet and dry surfaces, especially skin).

[0017] The term "(meth)acrylate" refers to the monomer acrylate or methacrylate of an alcohol. Acrylate and methacrylate monomers or oligomers are collectively referred to herein as "(meth)acrylates". A material referred to as "(meth)acrylate-based" is a material that contains a majority of one or more (meth)acrylates and may also contain copolymerizable monomers.

[0018] The terms "room temperature" and "ambient temperature" are used interchangeably to mean a temperature in the range of 20°C to 25°C.

[0019] The terms "Tg" and "glass transition temperature" are used interchangeably. If measured, unless otherwise specified, the Tg value is determined by differential scanning calorimetry (DSC) at a scan rate of 10°C / minute. Typically, the Tg value of a copolymer is not measured, but is calculated using the well-known Fox equation and the monomer Tg values provided by the monomer supplier, as understood by those skilled in the art.

[0020] As used herein, when referring to two layers, the term "adjacent" means that the two layers are close to each other with no intervening open space therebetween. They can be in direct contact with each other (e.g., laminated together), or an intervening layer may be present.

[0021] The terms "polymer" and "macromolecule" as used herein are consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeating subunits. As used herein, the term "macromolecule" 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 by a polymerization reaction.

[0022] The term "protein leather" is used herein according to its commonly understood meaning. Protein leather, also known as artificial leather, is composed of protein powder and resin to form a flexible sheet. These sheets are similar to leather in appearance and durability.

[0023] The term "alkyl" refers to a monovalent group that is a radical of an alkane, which is a saturated hydrocarbon. The alkyl can be straight-chain, branched-chain, cyclic, or a combination thereof, and generally has 1 to 20 carbon atoms. In some embodiments, the 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, and ethylhexyl.

[0024] The term "alkenyl" refers to a monovalent group that is a radical of an alkene, which is an unsaturated hydrocarbon. The alkenyl can be straight-chain, branched-chain, cyclic, or a combination thereof, and generally has 3 to 20 carbon atoms. In some embodiments, the alkenyl group contains 3 to 18, 3 to 12, 3 to 10, 3 to 8, 3 to 6, or 3 to 4 carbon atoms.

[0025] The term "aryl" refers to a monovalent group that is an aromatic and carbocyclic ring. The aryl can have one to five rings attached to or fused to the aromatic ring. Other ring structures can be aromatic, non-aromatic, or a combination thereof. Examples of aryl groups include, but are not limited to: phenyl, biphenyl, terphenyl, anthryl, naphthyl, acenaphthylenyl, anthraquinonyl, phenanthryl, anthracenyl, pyrenyl, perylenyl, and fluorenyl.

[0026] The term "alkylene" refers to a divalent group that is the radical of an alkane. The alkylene can be straight-chain, branched-chain, cyclic, or a combination thereof. The alkylene typically has from 1 to 20 carbon atoms. In some embodiments, the alkylene contains from 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. The radical centers of the alkylene can be on the same carbon atom (i.e., alkylidene) or on different carbon atoms.

[0027] The term "heteroalkylene" refers to a divalent group that includes at least two alkylene groups linked by thio, oxy, or -NR- (where R is an alkyl group). The heteroalkylene can be straight-chain, branched-chain, cyclic, substituted with alkyl groups, or a combination thereof. Some heteroalkylenes are polyoxyalkenes, where the heteroatom is oxygen, such as, for example, -(CH2CH2O) n CH2CH2O-. The terms "polyoxyalkene" and "polyalkylene oxide" are used interchangeably. As used herein, the term "alkylene oxide group capped with an alkyl group" refers to a monovalent group containing a polyoxyalkylene group capped with -(CH2CH2O) n CH2CH2OR of the type, where R is an alkyl group.

[0028] The terms "radically polymerizable" and "ethylenically unsaturated" are used interchangeably and refer to a reactive group containing a carbon-carbon double bond that is capable of polymerizing via a free radical polymerization mechanism.

[0029] Articles are disclosed herein, particularly medical articles, that include a substrate and a layer on at least a portion of the substrate, where the layer comprises at least one hot-melt processable pressure-sensitive adhesive that has been coated and photocrosslinked. The at least one hot-melt processable pressure-sensitive adhesive comprises a (meth)acrylate-based copolymer that is a reaction product of a reaction mixture. The reaction mixture comprises polymerizable components, at least one initiator, and optionally non-polymerizable components. The polymerizable components comprise at least one first (meth)acrylate monomer of formula I:

[0030] CH2=CR 1 -(CO)-OR 2

[0031] Formula I

[0032] where R 1 is hydrogen or a methyl group; and R 2 is an alkyl, alkenyl, or aryl group containing from 4 to 20 carbon atoms; at least one second (meth)acrylate monomer of formula II:

[0033] CH2=CR 1 -(CO)-OR 3

[0034] Formula II

[0035] wherein R 1 is hydrogen or a methyl group, and R 3 is an epoxyalkyl group capped with an alkyl group, at least one copolymerizable reinforcing monomer, and at least one copolymerizable photo - crosslinking agent. Each of the reactive components, initiators, and optional components is described in more detail below.

[0036] The adhesive composition is hot - melt processable. The term "hot - melt processable" is not a process description or limitation, but rather a material description, meaning that the adhesive composition is capable of being hot - melt processed, rather than that the composition must have been hot - melt processed or needs to be hot - melt processed.

[0037] The articles of the present disclosure include a substrate. A variety of substrates are suitable for the articles of the present disclosure. In many embodiments, the substrate includes a substrate suitable for use in medical articles. These articles may or may not be breathable, that is, permeable to moisture. Examples of suitable substrates include medical substrates or release liners. Exemplary medical substrates include polymeric materials, plastics, natural macromolecular materials (e.g., collagen, wood, cork, silk, and leather), paper, cloth, fabric, non - woven fabric, composite materials, and combinations thereof. The medical substrate may be back - lined. Examples of suitable back - lined substrates include breathable conformable back - liners, on which the adhesive is disposed. A variety of breathable, conformable back - liners are suitable for the articles of the present disclosure. Generally, the breathable, conformable back - liners include woven or knitted textiles, non - woven fabrics, or plastics.

[0038] In some embodiments, the breathable, conformable back - liner includes a highly moisture - permeable membrane back - liner. Examples of such back - liners, methods of preparing such membranes, and methods of testing their permeability are described, for example, in U.S. Patent Nos. 3,645,835 and 4,595,001. Generally, such back - liners are porous materials.

[0039] Generally speaking, the back - liner is conformable to an anatomical surface. Thus, when the back - liner is applied to an anatomical surface, the back - liner conforms to the surface even when the surface moves. Generally speaking, the back - liner is also conformable to an animal anatomical joint. When the joint flexes and then returns to its unflexed position, the back - liner stretches to accommodate the flexion of the joint, but when the joint returns to its unflexed state, the back - liner has sufficient elasticity to continue to conform to the joint.

[0040] Examples of particularly suitable back - liners can be found in U.S. Patent Nos. 5,088,483 and 5,160,315 and include elastomeric polyurethane, polyester, or polyether block amide membranes. These membranes have a combination of desired properties, including resilience, high moisture permeability, and transparency.

[0041] In some embodiments, the substrate can be a release liner. A release liner is a sheet material having a low adhesion coating on at least one surface. The thermally processable pressure-sensitive adhesive of the present disclosure can be disposed on the release liner to produce an article comprising a pressure-sensitive adhesive layer on the release liner. Such an adhesive / release liner article can be used to prepare other adhesive / substrate articles by laminating the adhesive layer onto a different substrate and then removing the release liner. This allows the adhesive to be set onto substrates on which it is difficult to directly set a thermally processable pressure-sensitive adhesive, such as heat-sensitive substrates. The adhesive / release liner article can also be used to apply a pressure-sensitive adhesive layer to an article, such as an electrode, a stoma device, etc. The device can be airtight.

[0042] Also disclosed herein is a thermally processable pressure-sensitive adhesive composition. The composition is disposed on a substrate to form an adhesive layer, and then the adhesive layer is photocrosslinked to form a photocrosslinked pressure-sensitive adhesive layer. Thus, the article also comprises at least one thermally processable pressure-sensitive adhesive layer that has been coated and photocrosslinked. The so-called at least one means that the layer can comprise a single thermally processable pressure-sensitive adhesive composition or it can contain more than one thermally processable pressure-sensitive adhesive composition, where different compositions can be blended or present in separate sublayers within the layer.

[0043] The thermally processable pressure-sensitive adhesive composition comprises a (meth)acrylate-based copolymer, which is the reaction product of a reaction mixture. The reaction mixture comprises polymerizable components, at least one initiator, and optionally non-polymerizable components. The polymerizable components comprise at least one first (meth)acrylate monomer, at least one second (meth)acrylate monomer, at least one copolymerizable reinforcing monomer, at least one copolymerizable photocrosslinker, and at least one initiator. The reaction mixture can also comprise optional components. Each of the reactive components, initiator, and optional components is described in more detail below.

[0044] As mentioned above, the reaction mixture comprises at least one first (meth)acrylate monomer of formula I:

[0045] CH2=CR 1 -(CO)-OR 2

[0046] Formula I

[0047] wherein R 1 is hydrogen or a methyl group; and R 2 is an alkyl, alkenyl, or aryl group containing 4 to 20 carbon atoms. In some embodiments, R 2is an alkyl group containing 4 to 12 carbon atoms. In many embodiments, the first (meth)acrylate monomer comprises a mixture of (meth)acrylate monomers. Examples of suitable first (meth)acrylate monomers include BA (butyl acrylate), PA (propyl acrylate), HA (hexyl acrylate), 2-EHA (2-ethylhexyl acrylate), IOA (isooctyl acrylate), heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, and dodecyl acrylate. Examples of particularly suitable first (meth)acrylate monomers include BA (butyl acrylate), 2-EHA (2-ethylhexyl acrylate), IOA (isooctyl acrylate), and LA (lauryl acrylate).

[0048] The reaction mixture further comprises at least one second (meth)acrylate monomer having the general formula II:

[0049] CH2=CR 1 -(CO)-OR 3

[0050] Formula II

[0051] wherein R 1 is hydrogen or a methyl group, and R 3 is an epoxyalkyl group capped with an alkyl group. In some embodiments, R 3 is a poly(ethylene oxide) group capped with an alkyl group. In some particularly suitable embodiments, R 3 has the general formula III:

[0052] -(CH2-CH2-O) n -CH3

[0053] Formula III

[0054] wherein n is an integer from 8 to 230. Examples of suitable second (meth)acrylate monomers include acrylates formed from CARBOWAX 750 (methoxypolyethylene glycol with a molecular weight of 750) and MPEG 500 (methoxypolyethylene glycol acrylate with a molecular weight of 550).

[0055] The reaction mixture further comprises at least one copolymerizable enhancing monomer. The copolymerizable enhancing monomers are monoethylenically unsaturated monomers that increase the glass transition temperature and the cohesive strength of the copolymer. Mixtures of enhancing monomers can also be used. Generally, the enhancing monomers have a homopolymer Tg of at least about 10 °C. Generally, the enhancing monomers are enhancing (meth)acrylic monomers, including acrylic acid, methacrylic acid, acrylamide or (meth)acrylates. Examples include, but are not limited to, acrylamides such as acrylamide, methacrylamide, N-methylacrylamide, N-ethylacrylamide, N-hydroxyethylacrylamide, diacetoneacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-ethyl-N-aminoethylacrylamide, N-ethyl-N-hydroxyethylacrylamide, N,N-dihydroxyethylacrylamide, tert-butylacrylamide, N,N-dimethylaminoethylacrylamide, and N-octylacrylamide. Other examples of enhancing monomers include itaconic acid, crotonic acid, maleic acid, fumaric acid, 2,2-(diethoxy)ethyl acrylate, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate or 3-hydroxypropyl methacrylate, methyl methacrylate, isobornyl acrylate, 2-(phenoxy)ethyl acrylate or 2-(phenoxy)ethyl methacrylate, biphenyl acrylate, tert-butylphenyl acrylate, cyclohexyl acrylate, dimethyladamantyl acrylate, 2-naphthyl acrylate, phenyl acrylate, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, and N-vinylcaprolactam. Particularly suitable enhancing monomers are acid-functional monomers. Acrylic acid is particularly useful because it is readily available.

[0056] The reaction mixture further comprises at least one copolymerizable photo-crosslinker. The copolymerizable photo-crosslinkers are materials that contain free-radically polymerizable groups for copolymerizing with the monomers described above. The copolymerizable photo-crosslinkers also contain photosensitive groups that, upon exposure to light of an appropriate wavelength (generally high-intensity ultraviolet (UV) radiation), form free radicals that can form crosslinked moieties in the polymer. If a photoinitiator is used to form a (meth)acrylate-based polymer, the photo-crosslinker is not activated by light of the same wavelength as the photoinitiator. In this way, the copolymerizable photo-crosslinker is incorporated into the polymer and can be thermally processed because the crosslinker is thermally stable and remains intact until activated by light of an appropriate wavelength. This prevents the copolymerizable photo-crosslinker from becoming activated until the polymer has been hot melt coated. In some embodiments, these crosslinkers are activated by UV light generated from an artificial source such as a medium-pressure mercury lamp or a UV black light.

[0057] Suitable photo-crosslinking agents in the monoethylenically unsaturated aromatic ketone comonomers do not contain ortho-aromatic hydroxyl groups, such as those described in U.S. Patent No. 4,737,559 (Kellen et al.). Specific examples include p-acryloyloxybenzophenone (ABP), p-acryloyloxyethoxybenzophenone (AEBP), ketalized acryloyloxyethoxybenzophenone (KAEBP) (as described in U.S. Patent No. 10,189,771 (Benson et al.)), p-N-(methacryloyloxyethyl)-carbamoylethoxybenzophenone, p-acryloyloxyacetophenone, o-acrylaminobenzophenone, acrylated anthraquinone, etc. Particularly suitable are ABP p-acryloyloxybenzophenone (also known as 4-acryloyloxybenzophenone), AEBP (p-acryloyloxyethoxybenzophenone), and KAEBP (ketalized acryloyloxyethoxybenzophenone).

[0058] The reaction mixture further comprises at least one initiator. Generally, the initiator is a photoinitiator, which means that the initiator is activated by light (usually ultraviolet (UV) light). As mentioned above, suitable photoinitiators are those activated by light different from the light that activates the photo-crosslinking. Photoinitiators are well known to 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, which are commercially available from BASF, Charlotte, NC. The photoinitiator IRGACURE 1173 is particularly suitable.

[0059] The relative amounts of the components of the reaction mixture can vary as needed. In some embodiments, the reaction mixture comprises:

[0060] 50 to 85 parts by weight of at least one first monomer;

[0061] 10 to 30 parts by weight of at least one second monomer;

[0062] 3 to 25 parts by weight of at least one copolymerizable reinforcing monomer;

[0063] 0.05 to 0.5 parts by weight of at least one copolymerizable photo-crosslinking agent; and

[0064] 0.01 to 1.0 parts by weight of an initiator.

[0065] The term "parts by weight" is used to describe the amounts by weight of the reactive materials present in a mixture. This term is similar to but should not be confused with "weight %" or "% weight". Usually, the components total 100 parts by weight, so parts by weight is the same as weight %, but in many embodiments, the reactive components do not total exactly 100 parts by weight. In these embodiments, the term parts by weight is close to but not exactly the same as weight %. For example, a reaction mixture containing 70 parts by weight of a first monomer, 20 parts by weight of a second monomer, 10 parts by weight of a copolymerizable reinforcing monomer, and 0.1 parts by weight of a copolymerizable photo - crosslinking agent has approximately 70 weight % of the first monomer, but it is incorrect to use the term since the parts by weight of the monomers total more than 100.

[0066] The reaction mixture used to prepare the at least one hot - melt - processable pressure - sensitive adhesive may contain additional optional additives. The additives may or may not react with the reactive components described above. Reactive additives include chemical cross - linkers (also known as covalent cross - linkers) and chain - transfer agents. Non - reactive additives include antioxidants and plasticizers.

[0067] The cross - linker, if used, is used in an effective amount, meaning an amount sufficient to cause cross - linking without interfering with the hot - melt processability of the adhesive composition during polymerization. Usually, the cross - linker, if used, is used in an amount less than 0.01 parts by weight.

[0068] One useful class of cross - linkers is the polyfunctional (meth)acrylate materials. Polyfunctional (meth)acrylates include tri(meth)acrylates and di(meth)acrylates (i.e., compounds containing three or two (meth)acrylate groups). Usually, di(meth)acrylate cross - linkers (i.e., compounds containing two (meth)acrylate groups) are used. Useful di(meth)acrylates include, for example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,4 - butanediol di(meth)acrylate, 1,6 - hexanediol di(meth)acrylate, alkoxylated 1,6 - hexanediol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, cyclohexanedimethanol di(meth)acrylate, alkoxylated cyclohexanedimethanol diacrylate, ethoxylated bisphenol A di(meth)acrylate, neopentyl glycol diacrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and urethane di(meth)acrylate. Di(meth)acrylate HDDA (1,6 - hexanediol diacrylate) is particularly suitable.

[0069] A particularly suitable optional 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 (isooctyl thioglycolate). The use of chain transfer agents and chain transfer agents is well known in the field of adhesives. If used, the chain transfer agent is typically present in an amount of up to 0.30 parts by weight.

[0070] As mentioned above, the reaction mixture may contain non-reactive components that perform useful functions in the adhesive layer when forming the adhesive layer but do not participate in the polymerization reaction to form the adhesive composition. Suitable additives are those that do not interfere with the polymerization reaction. Examples include plasticizers and antioxidants, with antioxidants being particularly suitable. Commercially available antioxidants include the IRGANOX series from BASF, such as IRGANOX 1076 and IRGANOX 1010. Typically, if used, the antioxidant is present in an amount of up to 0.5 parts by weight.

[0071] A hot-melt processable adhesive composition is formed by polymerizing a reaction mixture containing the components described above. Polymerization is typically initiated by a photoinitiator. The polymerization can be carried out in a solvent or as a 100% solid mixture. Generally, 100% solid polymerization is more desirable. In some embodiments, the reactive components are mixed and polymerized in the absence of a solvent to form a hot-melt processable pressure-sensitive adhesive composition.

[0072] In many embodiments of the present disclosure, the polymerization is carried out within a sealed package, as described in U.S. Patent No. 5,804,610 (Hamer et al.). In this method, the reaction mixture components described above are sealed within a package containing a thermoplastic material. These packages are then polymerized to form a hot-melt processable pressure-sensitive adhesive composition within the package.

[0073] In this method, two segments of thermoplastic film are heat-sealed together across the bottom and at each lateral edge on a liquid form-fill-seal machine to form an end-open pouch. Particularly suitable thermoplastic film materials are polyethylene and EVA (ethylene vinyl acetate). The reaction mixture is pumped through a hose to fill the pouch, and then the pouch is heat-sealed across the top to completely enclose the adhesive composition.

[0074] Generally, the reaction mixture is polymerized by activating the photoinitiator with radiation of an appropriate wavelength (usually UV radiation). In many embodiments, the pre-adhesive composition in the package is immersed in a heat exchange medium to moderate the generation of excessive heat during polymerization. In many embodiments, the heat exchange medium is water maintained at room temperature.

[0075] After polymerization, a packaged adhesive composition is produced. This packaged adhesive composition can be used immediately, stored for later use, or transported to different locations for hot melt processing.

[0076] The adhesive layer of the article of the present disclosure is formed by: disposing at least one of the hot melt processable pressure sensitive adhesive compositions described above onto the surface of a substrate to form an adhesive layer, and then photocrosslinking the adhesive layer by exposing the adhesive layer to actinic radiation.

[0077] The adhesive composition can be applied to the surface by any conventional application method, including but not limited to extrusion coating, gravure coating, curtain coating, slot coating, spin coating, screen printing, transfer coating, brush coating, or roll coating, etc. The adhesive composition can be applied to the microstructured surface as a hot melt composition, a solvent-based composition, or a 100% solid composition. The adhesive coating can be further processed to produce an adhesive layer. The processing can include drying the adhesive layer coating (if it is solvent-based) or cooling the adhesive layer coating (if it is hot melt coated).

[0078] In many embodiments, the hot melt processable pressure sensitive adhesive composition can be applied to the surface of the substrate by hot melt coating. Hot melt coating is particularly suitable when the adhesive composition is prepared as a 100% solid composition. This eliminates the need to dry the applied adhesive composition and eliminates the need to use solvents. Optional components such as antioxidants, plasticizers, or tackifiers can be added to the hot melt processable pressure sensitive adhesive composition. These optional additives can be added in addition to or in place of adding additives to the reaction mixture.

[0079] A variety of hot melt blending techniques using various hot melt blending equipment are applicable to the processing of hot melt processable pressure sensitive adhesive compositions. Batch blending equipment and continuous blending equipment can be used. Examples of batch methods include those using a BRABENDER (such as a BRABENDER PREP CENTER, commercially available from C.W. Brabender Instruments, Inc., South Hackensack, NJ) or BANBURY internal mixing and roll milling equipment (such as equipment available from Farrel Co., Ansonia, CN). Examples of continuous methods include single screw extrusion, twin screw extrusion, disk extrusion, reciprocating single screw extrusion, and pin barrel single screw extrusion. Continuous methods can utilize distribution elements, pin mixing elements, static mixing elements, and dispersing elements such as MADDOCK mixing elements and SAXTON mixing elements. A single hot melt blending device can be used, or a combination of hot melt blending equipment can be used to process the adhesive compositions of the present disclosure.

[0080] The output of the hot melt blend is coated onto a substrate to form an adhesive layer. If batch equipment is used, the resulting hot melt blend can be removed from the equipment and placed in a hot melt coater or extruder and coated onto the substrate. If an extruder is used to prepare the hot melt blend, the blend can be directly extruded onto the substrate to form an adhesive layer in a continuous forming method. In a continuous forming method, the adhesive can be drawn from a film die and then contacted with the substrate surface.

[0081] In many embodiments of the present disclosure, the hot melt processable pressure sensitive adhesive composition comprises a hot melt processable packaged adhesive composition. The method for preparing the hot melt processable packaged adhesive composition is as described above. The hot melt processable packaged adhesive composition is formed by surrounding the reaction mixture components described above in a package containing a thermoplastic material and polymerizing the reactive components within the package. Then the package can be added to an extruder, additional optional components can be added if desired, and the adhesive composition is hot melt coated onto the surface of the substrate.

[0082] The adhesive layer so formed can be a continuous layer, a patterned layer, or a combination thereof. Additionally, the adhesive layer can include sublayers. The sublayers can be the same adhesive material, or they can be different adhesive materials. If the sublayers are different materials, the different materials are typically hot melt processable pressure sensitive adhesive compositions of the type described above. The sublayers can also be continuous layers or patterned layers. In some embodiments, the adhesive layer includes two sublayers, a first sublayer comprising a continuous layer, and a second sublayer disposed on the first sublayer in a pattern.

[0083] After a hot-melt processable pressure-sensitive adhesive layer is disposed on a substrate surface, the hot-melt processable pressure-sensitive adhesive layer is photocrosslinked by subjecting the adhesive layer to a photocrosslinking process. In this method, a photosensitive crosslinking agent is activated by exposure to a high-intensity UV lamp to achieve crosslinking. Examples of suitable UV lamps include medium-pressure mercury lamps.

[0084] The thickness of the photocrosslinked adhesive layer can vary depending on a variety of factors such as the desired use of the adhesive article, whether the adhesive layer contains sublayers, and the like. Generally, the thickness of the adhesive layer can range from about 0.05 microns to about 200 microns.

[0085] As mentioned above, the adhesive articles of the present disclosure have a variety of desirable properties. Many of these properties make the adhesive articles particularly suitable for medical applications. As mentioned above, one particularly desirable feature is a high moisture vapor transmission rate (MVT). This property can be measured in a variety of ways. The MCT measurement method used in the present disclosure and described in the Examples section uses articles including a polyurethane film substrate having an adhesive layer. Such articles have a 24-hour inverted moisture vapor transmission rate (MVT) of 350 g / m 2 -20,000 g / m 2 .

[0086] In addition, desirable properties of the articles of the present disclosure include adhesion to both wet and dry surfaces. This property makes the adhesive articles suitable for use on wet or dry skin. The adhesion of the adhesive articles to wet or dry skin can be modeled in a variety of ways. In the present disclosure, protein leather is used as a particularly suitable test surface. Protein leather refers to artificial leather (sometimes referred to as synthetic leather) formed from a protein powder together with a resin to form a flexible sheet. These sheets are similar to leather in appearance and durability. The use of protein leather in sample testing is explained in detail in the Examples section. A particularly suitable protein leather is Protein Leather PBZ13001 KAKI from IDEATEX Japan Co.

[0087] In some embodiments, the adhesion of the adhesive article to dry protein leather is from 40 grams per inch to 400 grams per inch. In some embodiments, the adhesion of the adhesive article to wet protein leather is from 30 grams per inch to 300 grams per inch.

[0088] Examples

[0089] These examples are for illustrative purposes only and are not meant to limit the scope of the appended claims. Unless otherwise noted, all parts, percentages, ratios, etc. in the examples and the remainder of the specification are by weight. Unless otherwise noted, the solvents and other reagents used were obtained from Sigma-Aldrich Chemical Company, Milwaukee, Wisconsin, USA. The following abbreviations are used: m = meter; cm = centimeter; mm = millimeter; nm = nanometer; in = inch; RPM = revolutions per minute; oz = ounce; g = gram; kg = kilogram; lb = pound; mL = milliliter; dL = deciliter; Pa = Pascal; h = hour; mW = milliwatt; mJ = millijoule; kGy = kilogray; PPM = parts per million.

[0090] Abbreviation Table

[0091]

[0092] Preparation of "100% Solid" or "Bulk" Polymers Used in Examples

[0093] A monomer mixture was prepared by blending reactive acrylic monomers, a photoinitiator, and an antioxidant in a wide-mouth bottle. A magnetic stir bar was added to the mixture, and the mixture was placed on a stirring plate to form a curable composition. An EVA film was heat-sealed to form an open-ended container, each with dimensions of 18 cm × 5 cm. Each container was filled with approximately 24 grams of the curable composition. Air was evacuated from the open end, and then it was sealed using a heat sealer (available under the trade name "MIDWEST PACIFIC IMPULSESEALER" from J.J. Elemer Corp., St. Louis, MO, USA). The sealed EVA film container enclosing the curable composition was immersed in a constant temperature water bath at 16 °C, and ultraviolet light (365 nm, 4.5 mW / cm 2 ) was irradiated for nine minutes on each side to polymerize the curable composition.

[0094] Test Methods

[0095] Test Method 1A: Determination of Gel Content

[0096] Place approximately 24 g of a rectangular polymer sample onto the center of a pre-weighed rectangular mesh. The mesh is a type 304 stainless steel square woven wire cloth of a woven structure, 150 mesh, using 0.0026 inch (66 µm) wire and 0.0041 inch (104 µm) openings (obtained from McMaster-Carr Co., Elmhurst, IL, USA under the trade name "MCMASTER-CARR"). Fold the overhanging portions of the mesh inward to cover and secure the sample inside the mesh. Weigh the folded mesh with the encapsulated polymer, then immerse it in approximately 8 ounces (approximately 240 mL) of ethyl acetate inside a glass wide-mouth bottle, which is placed on a mechanical roller for 24 hours. Then remove the mesh with the polymer from the bottle and dry it in an oven at 120 °C for 30 minutes, and weigh it again to calculate the sample mass. The gelated insoluble portion of the polymer is calculated as the gel weight percentage ("gel weight %") using the following formula:

[0097]

[0098] Test Method 1B: Determination of Gel Content

[0099] Compound the sample in a Bonnot. Pump the heated sample into a twin-screw extruder. Coat the resulting hot melt onto a silicone release liner using a rod coater die. The extrusion temperatures of the die and the extruder are maintained at 320 °F (160 °C). The extruded sample is coated at a thickness of 1.5 mils (38 µm). Then immediately use a UV fusion lamp and an H-type bulb at 40 mJ / cm 2 to 50 mJ / cm 2Samples cured under UV-C. Approximately 1 g to 2 g of the polymer sample was placed onto the center of a pre-weighed rectangular mesh. The mesh was a type 304 stainless steel square woven wire cloth of a woven structure, 150 mesh, using 0.0026 inches (66 microns) wire and 0.0041 inches (104 microns) openings (obtained from McMaster-Carr Co., Elmhurst, IL, USA under the trade name "MCMASTER-CARR"). The overhanging portions of the mesh were folded inwards to cover and secure the sample inside the mesh. The folded mesh with the encapsulated polymer was weighed and then immersed in approximately 2 ounces of ethyl acetate inside a glass wide-mouth bottle, which was placed on a mechanical roller for 4 hours. The ethyl acetate containing the dissolved polymer was removed, 2 ounces of fresh ethyl acetate was added to the wide-mouth bottle, and the sample was rolled on the mechanical roller overnight. Then the mesh with the polymer was taken out of the wide-mouth bottle and dried in an oven at 65 °C for 16 hours and weighed again to calculate the sample mass. The gelated insoluble portion of the polymer was calculated as the percentage of gel weight ("gel weight %") using the following formula:

[0100]

[0101] Determination of Intrinsic Viscosity ("IV")

[0102] The inherent viscosity ("IV") reported herein was obtained by conventional methods known to those of ordinary skill in the art. The IV was obtained in a water bath controlled at 27 °C using a single-bath dilute solution polymer viscometer (obtained from Cannon Instrument Co., State College, PA, USA under the trade name "MINIPV-X") to measure the flow time of 10 mL of a polymer solution (0.25 g / dL polymer in ethyl acetate). The test procedures followed and the equipment used are described in detail in Textbook of Polymer Science, F. W. Billmeyer, Wiley-Interscience, Second Edition, 1971, Pages 84 and 85.

[0103] Adhesion Test to Steel

[0104] Cut the adhesion test specimens for steel, measured as 1.27 cm × 12.7 cm. Next, use a 2.0 kg steel roller to pass through twice in each direction to remove the liner from the adhesive and place the adhesive on the test panel. The test surface is #320 stainless steel. Conduct a peel test at room temperature at a separation rate of 30.5 cm / min using a Zwick tensile tester (Z005) equipped with a 50 kg load cell. Record the average peel force and use it to calculate the average peel adhesion strength in g / cm. This test is repeated six times. The reported results are the average of 3 measurements, expressed in ounces per inch or oz / 25 mm, and converted to Newtons per decimeter (N / dm).

[0105] Shear Test

[0106] Cut the shear test specimens, measured as 1 inch × 3 inches (2.54 cm × 7.62 cm). Hang a 1-inch (2.54 cm) sample on the edge of the panel and fold it over the center of the adapter cover, ensuring that the ends are folded straight back and the folded part is at least 1 inch (2.54 cm) long. The area between the panel and the hook is reinforced and stapled with orange tape. Transfer the board to the shear table, hang a 500 g weight on the hook, and record the time until the weight drops.

[0107] MVTR Test

[0108] Complete the moisture vapor transmission rate (MVTR) test using the method based on European Standard EN 13726-2-2002. Pre-cut the sample to a diameter of 55.6 mm. Place a foil ring with an inner diameter of 42 mm and an outer diameter of 62 mm on the dressing sample.

[0109] To test the upright MVTR, place 20 mL of deionized water inside the cup, then place the pre-cut 55.6 mm diameter sample with the foil ring on the opening of the cup, with the adhesive side facing down. Then place the top plate on top of the sample and tighten the screw. Weigh the cup and record the mass of the cup, sample, and liquid as W1. Place the cup in a chamber at a temperature of 37°C ± 1°C and a relative humidity of 19%, with the sample facing up and not in contact with the liquid. After 18 to 24 hours, remove the cup from the chamber and immediately re-weigh the cup, sample, and liquid, and record the mass as W2. Record the time the cup was in the chamber as T1. Calculate the upright MVTR using the following formula:

[0110]

[0111] Where:

[0112] X is the upright MVTR (g m -224 h -1 )

[0113] W1 is the mass of the cup, sample, and liquid before the test period

[0114] W2 is the mass of the cup, sample, and liquid after the test period

[0115] T1 is the test time in hours

[0116] For the inverted MVTR measurement, use a new set of dressings and cups. Use 30 ml of deionized water for the inverted MVTR test. Invert the cup and place it in the chamber so that the sample faces down and is in contact with the liquid. After 4 hours, remove the cup from the chamber and immediately reweigh the cup, sample, and liquid, and record the mass as W3. Record the time the cup was in the chamber as T2. Calculate the inverted MVTR using the following formula

[0117]

[0118] Where

[0119] X is the inverted MVTR (g m -2 24 h -1 )

[0120] W1 is the mass of the cup, sample, and liquid before the test period (i.e., before inverting the cylinder) with the test solution in contact with the dressing

[0121] W3 is the mass of the cup, sample, and liquid after the test period with the test solution in contact with the dressing

[0122] T2 is the test time in hours

[0123] If the inverted MVTR of the test sample is less than 1000 g m -2 24 h -1 , then place the sample back in the chamber for a total time of 18 to 24 hours and recalculate the results

[0124] Rheological Test

[0125] Perform rheological tests with a transfer adhesive using an ARES G2 rheometer equipped with an 8 mm parallel plate fixture (top) and a 25 mm parallel plate fixture (bottom). Conduct small amplitude oscillatory shear at 10 rad / s while increasing the temperature from 25 °C to 130 °C at a rate of 10 °C / min

[0126] Adhesion to Protein Leather

[0127] Test Substrate: Protein leather PBZ13001 KAKI (IDEATEX Japan), protein leather is made from a special resin and protein powder. Protein leather PBZ has an excellent touch similar to human skin, and many cosmetic companies use it for cosmetic testing applications.

[0128] * Synthetic Sweat Dispersion : Synthetic sweat dispersion is used for wet adhesion testing and is prepared by mixing the following materials.

[0129] Synthetic sweat dispersion: 750 ml synthetic sweat + 0.75 g synthetic sebum

[0130]

[0131] Dry Adhesion to Protein Leather

[0132] A sample strip with a size of 25 mm × 125 mm is laminated on a PL with a size of 30 mm × 125 mm using a 2 kg roller. The applied strip is removed by T-peel using a peel tester SP-2100 (Imass) at a test speed of 150 mm / min, and the average peel adhesion is recorded.

[0133] Wet Adhesion to Protein Leather

[0134] The synthetic sweat dispersion is sprayed onto the protein leather and allowed to stay for 10 minutes to 40 minutes. After wiping the protein leather, the synthetic sweat dispersion is sprayed again (5 times). The T-peel adhesion is measured by the same procedure as the dry adhesion.

[0135] Shrinkage Test

[0136] Cut a piece of adhesive with a size of 10 cm × 10 cm on a release liner and fold it itself parallel to the coating direction of the solvent-free adhesive. Gently apply pressure and remove the release liner from the top. For the adhesive sample with a current size of 10 cm × 5 cm, fold the adhesive again parallel to the coating direction while gently applying pressure to obtain a 10 cm × 2.5 cm sample. Repeat the folding and pressure application process one more time to obtain a final sample size of 10 cm (length) × 1.25 cm (width) and define it as the non-relaxed length. Then place the adhesive sample in a talc bed and heat the adhesive in the talc to 65 °C for 3 minutes. Then measure the length of the sample to obtain the "relaxed" sample length. The shrinkage of the sample is defined as ("non-relaxed length" - "relaxed length") / "relaxed length".

[0137] Wet Shear Adhesion on Protein Leather

[0138] Cut samples of DCT (double-sided tape laminated to a Sontara backing) or ATT (adhesive transfer tape laminated to two release liners) into 25 mm × 25 mm sizes. After removing the liners, laminate the first adhesive surface layer onto a polycarbonate sheet (30 mm × 30 mm × 2 mm). Laminate a fine ribbon onto the other surface of the polycarbonate sheet when pulling the pull tub. Spray the synthetic sweat dispersion onto the protein leather and let it sit for 10 minutes to 40 minutes. After wiping the protein leather, spray the synthetic sweat dispersion again (5 times). After removing the second liner, place the test sample on the wet test substrate and then place a 275 g weight on it for 1 minute. Pull the filament tub horizontally at a test speed of 90 inches per minute and measure the peak adhesion in Newtons.

[0139] Examples

[0140] Example 1 (E-1A - E-1H)

[0141] Samples of the materials of Examples E-1A - E-1H in Table 1 (raw materials RM in parts by weight) were compounded in a twin-screw extruder at 300°F (149°C) and 300 rpm for three minutes. The resulting hot melt was coated onto a silicone release liner using a forging die. The extrusion temperature of the die and the extruder was maintained at 300°F (149°C). The extruded samples were coated to a thickness of 1.5 mils (38 microns). In a separate step, the samples were then cured using a UV fusion lamp and an H-type bulb under UV-C radiation of 40 mJ / cm 2 and then the samples were hand-laminated onto polyurethane to produce the final constructs. The gel content was tested and summarized as follows.

[0142] Table 1 Adhesive Composition and Gel Content Data

[0143]

[0144] Example 2 (E-2A -E-2D) and Comparative Example CE2

[0145] The solvent-free acrylate adhesives E-2A - E-2D and Comparative Example CE2 shown in Table 2 (raw materials RM in parts by weight) were pattern-coated onto a double-sided silicone-coated liner (Loparex, Hammond, WI) at a coating weight of 6 grains / 24 inches 2 (6 grains / 155 cm 2 ) and then at 50 mJ / cm 2They were UV cured (Hammer UV unit, H-type bulb) at a dose of

[0146] Table 2 Solvent-Free Adhesive Compositions and Properties ..

[0147]

[0148] Example 3 (E-3A – E-3C) and Comparative Example CE3

[0149] The solventless acrylate adhesives E-3A - E-3C and CE3 (raw materials RM in parts by weight) shown in Table 3 were pattern-coated onto a double-sided silicone-coated liner (Loparex, Hammond, WI) at a coating weight of 5.5 grains / 24 inches 2 (5.5 grains / 155 cm 2 ), then UV cured (Hammer UV unit, H-type bulb) at a dose of 40 mJ / cm 2 . They were laminated with a polyurethane film (Lubrizol, Wickliffe, OH) and then γ irradiated at approximately 30 kGy. The adhesion to steel and shear properties were tested and summarized in Table 2 below.

[0150] Table 3 Solvent-Free Adhesive Compositions and Properties

[0151]

[0152] Example 4 (E-4A -E-4I)

[0153] The solventless acrylate adhesives E-4A - E-4I (raw materials RM in parts by weight) shown in Table 4 were pattern-coated onto a double-sided silicone-coated liner (Loparex, Hammond, WI) at a coating weight of 5.5 grains / 24 inches 2 (5.5 grains / 155 cm 2 ), then UV cured (Hammer UV unit, H-type bulb) at a dose of 50 mJ / cm 2 . They were laminated with a polyurethane film (Lubrizol, Wickliffe, OH) and then γ irradiated at approximately 30 kGy. The adhesion to steel and moisture vapor transmission rate data are summarized in Table 4 below.

[0154] Table 4 Solvent-Free Adhesive Compositions and Properties

[0155]

[0156]

[0157] Example 5 (E-5A -E-5C and CE5A, CS5B)

[0158] The solventless acrylate adhesives E-5A - E-5C and CE5A (raw materials RM in parts by weight) shown in Table 5 were pattern-coated onto a double-sided silicone-coated liner (Loparex, Hammond, Wisconsin, USA) at a coating weight of 5.5 grains / 24 inches 2 (5.5 grains / 155 cm 2 ), and then UV-cured (Hammer UV unit, H-type bulb) at a dose of 50 mJ / cm 2 . CE5B adhesive was continuously coated without UV. The adhesives were laminated with a polyurethane film (Lubrizol, Wickliffe, OH, USA), and then γ-irradiated at approximately 30 kGy.

[0159] Table 5 Solvent-Free Adhesive Compositions

[0160]

[0161]

[0162] The samples were evaluated in the clinical study described below. A controlled, randomized, single-blind in-house clinical study was conducted. First, three groups of samples were cut into 3-inch (7.6 cm) strips and then applied to intact skin on the backs of healthy volunteers, which was prepared with 2% CHG (chlorhexidine gluconate) swabs (1.8%-2.2% CHG, 63%-77% alcohol). The first group of samples was removed using an IMASSSP-2100 to obtain T0 / pre-exercise skin adhesion data within a dwell time of 5 to 15 minutes after initial application. Then, the subjects were asked to run or walk on a treadmill to generate sweat to simulate a wet condition. When the subjects reached their target heart rate, they maintained the heart rate for 30 minutes, and then the T0 / post-exercise samples were removed using an IMASS SP-2100 to obtain skin adhesion data. Twenty-four hours later, the T24 / post-exercise samples were removed to obtain skin adhesion data. Before the removal of the T24 / post-exercise samples, edge lift in the numerical range of 0 - 100% was also observed and recorded. The results are summarized in Table 6 below.

[0163] Table 6 Skin Adhesion and Edge Warping Data

[0164]

[0165] EM-05-014900 n = 16.

[0166] Example 6 (E-6A -E-6D)

[0167] The solventless acrylate adhesives E-6A - E-6D shown in Table 7 (raw materials RM in parts by weight) were coated at a coating weight of 23.5 grains / 24 inches 2 (23.5 grains / 155 cm 2 ) onto a double-sided silicone-coated liner (Fujimori Kogyo, Film by na TSB / TSC), and then UV cured (Heraeus UV unit, H-type bulb) at a dose of 60 mJ / cm 2 . The adhesives were laminated with Sontara and then the adhesion to protein leather was tested. For Example E-6D, the wet shear of the sample before lamination to Sontara (referred to as ATT, for adhesive transfer tape) and the sample laminated to Sontara (referred to as DCT, for double-sided tape) on protein leather was tested according to the above test method. The results are presented in Table 7.

[0168] Table 7 Adhesive Compositions and Adhesion to Protein Leather

[0169]

[0170] Example 7 (E-7A – E-7F)

[0171] The solventless acrylate adhesives E-7A - E-7E shown in Table 8 (raw materials RM in parts by weight) were continuously coated or pattern-coated at a coating weight of 6 grains - 12 grains / 24 inches 2 (6 grains - 12 grains / 155 cm 2 ) onto a double-sided silicone-coated liner (Loparex, Hammond, Wisconsin, USA), and then UV cured (Hammer UV unit, H-type bulb) at a dose of 50 mJ / cm 2 - 60 mJ / cm 2 . Two layers of the adhesives were laminated together and then laminated onto Sontara (Glatfelter, Charlotte, NC, USA) or a polyurethane film (BASF, Ludwigshafen, Germany), and then γ-irradiated at approximately 30 kGy, and the adhesion to protein leather was tested (Table 9).

[0172] Table 8 Solvent-Free Adhesive Compositions

[0173]

[0174] Table 9 Sample Constructs and Adhesion to Protein Leather

[0175]

Claims

1. An article, the article comprising: a substrate; and a layer disposed on at least a portion of the substrate, the layer comprising at least one hot-melt processable pressure-sensitive adhesive that has been coated and photocrosslinked, the at least one hot-melt processable pressure-sensitive adhesive comprising a (meth)acrylate-based copolymer, the (meth)acrylate-based copolymer being a reaction product of a reaction mixture comprising: at least one first (meth)acrylate monomer of general formula I: CH2=CR 1 -(CO)-OR 2 Formula I wherein R 1 is a hydrogen or methyl group; and R 2 is an alkyl, alkenyl or aryl group having 4 to 20 carbon atoms; and at least one second (meth)acrylate monomer of general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 is an epoxyalkyl group capped with an alkyl group; at least one copolymerizable reinforcing monomer; at least one copolymerizable photocrosslinking agent; and at least one initiator.

2. The article according to claim 1, wherein the substrate comprises a polymer film, a fabric, a nonwoven, a foam, a paper, a mesh, an adhesive, or a release liner.

3. The article according to claim 1, wherein the at least one first (meth)acrylate monomer has the general formula I: CH2=CR 1 -(CO)-OR 2 Formula I wherein R 1 is a hydrogen or methyl group; and R 2 is an alkyl group having 4 to 12 carbon atoms.

4. The article according to claim 1, wherein the at least one second (meth)acrylate monomer has the general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 is a polyethylene oxide group capped with an alkyl group.

5. The article according to claim 1, wherein the at least one second (meth)acrylate monomer has the general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 Having the general formula III: -(CH2-CH2-O) n -CH3 Formula III wherein n is an integer from 8 to 230.

6. The article according to claim 1, wherein the at least one copolymerizable reinforcing monomer comprises an acid-functional monomer.

7. The article according to claim 1, wherein the reaction mixture comprises: 50 parts by weight to 85 parts by weight of at least one first monomer; 5 parts by weight to 30 parts by weight of at least one second monomer; 3 parts by weight to 25 parts by weight of at least one copolymerizable reinforcing monomer; 0.05 parts by weight to 0.5 parts by weight of at least one copolymerizable photocrosslinking agent; and 0.01 parts by weight to 1.0 parts by weight of at least one initiator.

8. The article according to claim 1, wherein the layer comprising at least one hot-melt processable pressure-sensitive adhesive comprises a continuous layer, a patterned layer, or a combination thereof.

9. The article according to claim 1, wherein the layer comprising at least one hot-melt processable pressure-sensitive adhesive comprises a layer of a first hot-melt processable pressure-sensitive adhesive composition forming a continuous layer and a second hot-melt processable pressure-sensitive adhesive composition forming a patterned layer.

10. The article according to claim 1, wherein the article comprises a polyurethane film substrate and has a 24-hour inverted moisture vapor transmission rate (MVT) of 350 g / m 2 to 20,000 g / m 2 .

11. The article according to claim 1, wherein the article has a peel adhesion to dry protein leather of 40 g / inch to 400 g / inch.

12. The article according to claim 1, wherein the article has a peel adhesion to wet protein leather of 30 g / inch to 300 g / inch.

13. The article according to claim 1, wherein the layer comprising the hot-melt processable pressure-sensitive adhesive further comprises at least one additive selected from antioxidants, tackifiers, and plasticizers.

14. An adhesive composition, the adhesive composition comprising: A hot-melt processable (meth)acrylate-based copolymer, said hot-melt processable (meth)acrylate-based copolymer being the reaction product of a reaction mixture comprising: At least one first (meth)acrylate monomer of general formula I: CH2=CR 1 -(CO)-OR 2 Formula I wherein R 1 is a hydrogen or methyl group; and R 2 is an alkyl, alkenyl or aryl group having 4 to 20 carbon atoms; And At least one second (meth)acrylate monomer of general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 is an epoxyalkyl group capped with an alkyl group; At least one copolymerizable reinforcing monomer; and At least one copolymerizable photo-crosslinking agent; and At least one initiator.

15. The adhesive composition according to claim 14, wherein the reaction mixture further comprises a chain transfer agent.

16. The adhesive composition according to claim 14, wherein the at least one first (meth)acrylate monomer has the general formula I: CH2=CR 1 -(CO)-OR 2 Formula I wherein R 1 is a hydrogen or methyl group; and R 2 is an alkyl group having 4 to 12 carbon atoms.

17. The adhesive composition according to claim 14, wherein the at least one second (meth)acrylate monomer has the general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 is a polyethylene oxide group capped with an alkyl group.

18. The adhesive composition according to claim 14, wherein the at least one second (meth)acrylate monomer has the general formula II: CH2=CR 1 -(CO)-OR 3 Formula II wherein R 1 is a hydrogen or methyl group; and R 3 Having the general formula III: -(CH2-CH2-O) n -CH3 Formula III wherein n is an integer from 8 to 230.

19. The adhesive composition according to claim 14, wherein the reaction mixture comprises: 50 to 85 parts by weight of at least one first monomer; 5 to 30 parts by weight of at least one second monomer; 3 to 25 parts by weight of at least one copolymerizable reinforcing monomer; 0.05 to 0.5 parts by weight of at least one copolymerizable photo-crosslinking agent; and 0.01 to 1.0 parts by weight of at least one initiator.

20. The adhesive composition according to claim 14, wherein the hot-melt processable (meth)acrylate-based copolymer is photo-crosslinkable.

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