Method of making polydiorganosiloxane adhesive with porous substrate and articles

Abstract

Adhesive (e.g., medical) articles are described that include a layer of a crosslinked non-functionalized polydiorganosiloxane adhesive composition having a first major surface and an opposing second major surface; and a porous substrate proximate to the first major surface, proximate to the second major surface, embedded within the polydiorganosiloxane adhesive layer, or a combination thereof. The porous substrate is a fibrous substrate or an open-cell organic polymer film. The pores can be formed prior to or after application of the polydiorganosiloxane adhesive composition.

Description

Summary of the Invention

[0001] Adhesive articles, such as medical articles, are described, comprising a layer of a crosslinked, nonfunctionalized polydiorganosiloxane adhesive composition having a first primary surface and an opposing second primary surface; and a porous substrate adjacent to the first primary surface, adjacent to the second primary surface, embedded within the polydiorganosiloxane adhesive layer, or a combination thereof.

[0002] The porous substrate is a fibrous substrate or an open-cell organic polymer membrane. The pores can be formed before or after the application of the polydiorganosiloxane adhesive composition.

[0003] In some embodiments, the thickness of the polydiorganosiloxane adhesive composition is at least 250 micrometers. In some embodiments, the article includes a plurality of pores extending through a porous substrate and a layer of crosslinked, nonfunctionalized polydiorganosiloxane adhesive composition.

[0004] Methods for manufacturing adhesive (e.g., medical) products are also described. Attached Figure Description

[0005] Figures 1 to 3 This is a schematic side view of an article comprising a cross-linked silicone adhesive and a porous substrate. Detailed Implementation

[0006] refer to Figures 1 to 3 The adhesive articles (100, 200, 300) typically include layers of crosslinked polydiorganosiloxane compositions provided on a carrier, such as a release liner (140, 240, 340) . The layers of the polydiorganosiloxane compositions also include a porous substrate (180, 280, 380). The layers of the polydiorganosiloxane compositions have a first primary surface (121, 221, 321) adjacent to the release liner carrier (140, 240, 340) and opposing second primary surfaces (123, 223, 323). The primary surfaces are generally parallel to each other. The thickness of one or more layers is a distance in a direction orthogonal to the primary surfaces.

[0007] Polydiorganosiloxane Composition

[0008] Silicone gel materials have been used in medical therapies to promote scar tissue healing. Slightly cross-linked silicone gels are soft, tacky, and elastic materials with low to moderate adhesive strength compared to traditional tackifying silicone PSA. Silicone gels are generally softer than silicone PSA, resulting in less discomfort when adhering to and removing from the skin. This combination of relatively low adhesive strength and moderate tack makes silicone gels suitable for gentle adhesive applications on the skin.

[0009] The crosslinked siloxane networks described in this paper are formed from nonfunctional organosilicon materials. These gel adhesives exhibit excellent wetting properties due to the very low glass transition temperature (Tg) and modulus of the polysiloxane networks.

[0010] Organosilicon materials are polydiorganosiloxanes, i.e., materials comprising a polysiloxane backbone. In some embodiments, nonfunctionalized organosilicon materials can be linear materials described by the following formula, which exemplifies a siloxane backbone having aliphatic and / or aromatic substituents:

[0011] R1, R2, R3, and R4 are independently selected from alkyl and aryl groups, each R5 is an alkyl group, and n and m are integers, with at least one of m or n being non-zero. In some embodiments, one or more of the alkyl or aryl groups may contain a halogen substituent, such as fluorine. For example, in some embodiments, one or more of the alkyl groups may be -CH2CH2C4F9.

[0012] In some embodiments, R5 is a methyl group, i.e., the nonfunctionalized polydiorganosiloxane material is end-capped with a trimethylsiloxy group. In some embodiments, R1 and R2 are alkyl groups, and n is zero, i.e., the material is poly(dialkylsiloxane). In some embodiments, the alkyl group is a methyl group, i.e., poly(dimethylsiloxane) (“PDMS”). In some embodiments, R1 is an alkyl group, R2 is an aryl group, and n is zero, i.e., the material is poly(alkylarylsiloxane). In some embodiments, R1 is a methyl group, and R2 is a phenyl group, i.e., the material is poly(methylphenylsiloxane). In some embodiments, R1 and R2 are alkyl groups, and R3 and R4 are aryl groups, i.e., the material is poly(dialkyldiarylsiloxane). In some embodiments, R1 and R2 are methyl groups, and R3 and R4 are phenyl groups, i.e., the material is poly(dimethyldiphenylsiloxane).

[0013] In some embodiments, the nonfunctionalized polydiorganosiloxane material may be branched. For example, one or more of the R1, R2, R3 and / or R4 groups may be linear or branched siloxanes having alkyl or aryl (including haloalkyl or aryl) substituents and a terminal R5 group.

[0014] As used herein, a “nonfunctional group” is an alkyl or aryl group consisting of carbon, hydrogen, and, in some embodiments, a halogen (e.g., fluorine) atom. As used herein, a “nonfunctionalized polydiorganosiloxane material” is a polydiorganosiloxane material in which the R1, R2, R3, R4, and R5 groups are nonfunctional groups.

[0015] Nonfunctionalized polydiorganosiloxanes do not contain functional groups (including hydride groups, hydroxyl groups, alkoxy groups, vinyl groups, epoxy groups and acrylate groups).

[0016] Polydiorganosiloxanes (such as polydimethylsiloxane PDMS) can be oils, fluids, gums, elastomers, or resins, such as brittle solid resins. Materials with lower molecular weights and lower viscosity are referred to as fluids or oils, while materials with higher molecular weights and higher viscosity are referred to as gums; however, there is no clear distinction between these terms. Silicone oils are commercially available (e.g., from Wacker) and have a viscosity of 0.65 mPa at 25°C. s to 1,000,000 mPa In typical embodiments, a high-viscosity (e.g., nonfunctional) liquid polydiorganosiloxane is preferred. In some embodiments, the liquid polydiorganosiloxane has a viscosity of at least 50,000 mPa at 25°C. s, 100,000 mPa s, 250,000 mPa s, 500,000 mPa s, 750,000 mPa s or 1,000,000 mPa When using polydiorganosiloxane adhesive, the viscosity at 25°C can exceed 1,000,000 mPa. s.

[0017] Skin-friendly adhesives are prepared by optionally combining one or more polydiorganosiloxane materials (e.g., silicone oils or fluids) with a suitable tackifying resin, coating the resulting combination, and crosslinking it using radiation (typically an electron beam (E-beam) or gamma radiation). Typically, any known additives that can be used in the adhesive formulation may also be included.

[0018] In some embodiments, silicate tackifying resins may be used. In some exemplary adhesive compositions, a variety of silicate tackifying resins may be used to achieve the desired properties.

[0019] Suitable silicate tackifying resins include those composed of the following structural units: M (i.e., monovalent R'3SiO) 1 / 2 Unit), D (i.e., divalent R'2SiO), 2 / 2 Unit), T (i.e., trivalent R'SiO), 3 / 2 Unit) and Q (i.e., quaternary SiO) 4 / 2(units) and combinations thereof. Typical exemplary silicate resins include MQ silicate tackifying resin, MQD silicate tackifying resin, and MQT silicate tackifying resin. These silicate tackifying resins typically have a number average molecular weight in the range of 100 gm / mol to 50,000 gm / mol, for example, 500 gm / mol to 15,000 gm / mol, and typically the R' group is a methyl group.

[0020] MQ silicate tackifying resin is a copolymer resin in which each M unit is bonded to a Q unit, and each Q unit is bonded to at least one other Q unit. Some Q units are bonded only to other Q units. However, some Q units are bonded to hydroxyl radicals, producing HOSiO 3 / 2 Unit (i.e., "T") OH (Unit), thereby obtaining the content of some silicon-bonded hydroxyl groups in the silicate tackifying resin.

[0021] Based on the weight of the silicate tackifying resin, the amount of silicon-bonded hydroxyl groups (i.e., silanols) on the MQ resin can be reduced to no more than 1.5 wt%, no more than 1.2 wt%, no more than 1.0 wt%, or no more than 0.8 wt%. This can be achieved, for example, by reacting hexamethyldisilazane with the silicate tackifying resin. This reaction can be catalyzed, for example, with trifluoroacetic acid. Alternatively, trimethylchlorosilane or trimethylsilylacetamide can be reacted with the silicate tackifying resin, in which case a catalyst is not necessary.

[0022] MQD silicone tackifying resin is a terpolymer having M, Q, and D units. In some embodiments, some methyl R' groups of the D unit can be replaced by vinyl (CH2=CH-) groups (“D…”). Vi (Unit) replacement. MQT silicate tackifying resin is a terpolymer having M, Q and T units.

[0023] Suitable silicate tackifying resins are commercially available from sources such as Dow Corning (e.g., DC 2-7066), Momentive Performance Materials (e.g., SR545 and SR1000), and Wacker Chemie AG (e.g., BELSIL TMS-803).

[0024] In some embodiments, the layer of the polydiorganosiloxane composition comprises at least 5%, 6%, 7%, 8%, 9%, or 10% by weight of a (e.g., silicate) tackifying resin. In some embodiments, the amount of (e.g., silicate) tackifying resin is no more than 20%, 25%, or 10% by weight. In other embodiments, the amount of (e.g., silicate) tackifier is less than 5%, 4%, 3%, 2%, or 1% by weight (e.g., zero).

[0025] In some embodiments, the polydiorganosiloxane composition may include any of a variety of known fillers (e.g., siliceous fillers, such as pyrolytic silica) and additives, including but not limited to pigments, additives for improving adhesion, additives for improving moisture permeability, antimicrobial agents (e.g., silver materials), pharmaceuticals, cosmetics, natural extracts, silicone waxes, silicone polyethers, hydrophilic polymers, and rheology modifiers. Hydrophilic additives for improving adhesion (particularly to wet surfaces) include polymers such as poly(ethylene oxide) polymers, poly(propylene oxide) polymers, and copolymers of poly(ethylene oxide and propylene oxide), acrylic polymers, hydroxyethyl cellulose polymers, carboxyethyl cellulose, silicone polyether copolymers, such as copolymers of poly(ethylene oxide) and polydiorganosiloxane, and copolymers of poly(propylene oxide) and polydiorganosiloxane, as well as blends thereof. The polydiorganosiloxane composition may contain various combinations of additives.

[0026] In some embodiments, the polydiorganosiloxane composition comprises up to 10%, 15%, 20%, 25%, or 30% by weight of filler and / or additives in the total polydiorganosiloxane composition. In other embodiments, the polydiorganosiloxane composition comprises less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% by weight of filler and / or additives.

[0027] Polysiloxane materials, tackifying resins (if present), and any optional additives can be combined using any of a variety of known methods prior to coating and crosslinking. For example, in some embodiments, the various components can be pre-blended using common equipment such as mixers, blenders, mills, extruders, etc.

[0028] In some embodiments, the material can be dissolved in a solvent, coated, and dried prior to crosslinking. In some embodiments, a solvent-free compounding and coating process can be used. In some embodiments, solvent-free coating can be performed at approximately room temperature. For example, in some embodiments, the material may have a kinematic viscosity of no more than 100,000 centistokes (cSt), such as no more than 50,000 cSt. However, in some embodiments, a hot-melt coating process such as extrusion can be used, for example, to reduce the viscosity of higher molecular weight materials to a value more suitable for coating. Various components can be added together in various combinations or individually through one or more separate ports of an extruder, blended (e.g., melt-mixed) within the extruder, and extruded to form a hot-melt coated composition.

[0029] Porous substrate

[0030] Various porous substrates can be used in the articles described herein. Porous substrates can be made from a variety of (e.g., thermoplastic) organic polymer materials, such as polyesters, polyurethanes, polyamides (e.g., nylon), polyimides, and polyolefins. In typical embodiments, the porous substrate is a fibrous web or an open-cell membrane. When the membrane is an open-cell membrane, the membrane can be opened before or after the crosslinking of the polydiorganosiloxane layer. Thus, although the articles contain porous substrates, in some embodiments, the method utilizes a non-porous organic polymer membrane substrate that has been imparted with porosity during manufacturing.

[0031] Fiber webs can be made from the same organic polymer materials (e.g., thermoplastic) just described. Fiber webs can also be made from various organic fibers (such as cotton, wool, hemp, and flax). Although inorganic fibers (e.g., glass fiber, ceramics, and metals) are generally not used in medical products, porous substrates with inorganic fibers can be used in other adhesive products. In some embodiments, the fiber web comprises nylon, polyolefins, or cellulose acetate. Fiber webs come in many forms, including, for example, woven webs, nonwoven webs, knitted fabrics, loose fabrics, and mesh.

[0032] In other embodiments, the porous substrate is an open-cell organic polymer membrane. Pores can be formed in the organic polymer membrane using suitable techniques (such as die stamping as described in KR10-2251386). Pores can be formed before or after the layer of the polydiorganosiloxane composition is applied to the organic polymer membrane. Pores can contribute to the membrane's moisture permeability.

[0033] In some embodiments, the organic polymer membrane comprises a membrane material having high moisture permeability (non-porous). Suitable membranes include (e.g., thermoplastic) polyurethane membranes, such as those available under the trade names PELLETHANE or ESTANE from Lubrizol, Brecksville, Ohio; elastomeric polyesters, such as those available under the trade name HYTREL from El. duPont deNemours & Co., Wilmington, Del.; and polyether ester block amides, such as those available under the trade name PEBAX from Elf Altochem North America, Philadelphia, Pa. Other available membranes are those described in U.S. Patent No. 4,499,896 (Heinecke); U.S. Patent No. 4,598,004 (Heinecke); and U.S. Patent No. 5,849,325 (Heinecke et al.). Typically, the membrane has higher tensile strength and lower elongation than the crosslinked layer of the polydiorganosiloxane composition, and therefore provides reinforcement and improved web processing. In some embodiments, the membrane has a maximum tensile strength of at least 20 MPa, 30 MPa, or 40 MPa, and typically no greater than 60 MPa, 50 MPa, or 40 MPa (ASTM D 412). In some embodiments, the membrane has a maximum elongation of at least 100%, 200%, 300%, 400%, or 500%, and typically no greater than 1000%, 750%, or 500% (ASTM D 412). In some embodiments, the membrane thickness is at least 25 micrometers, 50 micrometers, or 75 micrometers. In some embodiments, the membrane thickness is no greater than 200 micrometers, 150 micrometers, or 100 micrometers. Perforated membranes can have lower tensile strength and higher elongation compared to the same membrane without pores.

[0034] (For example, fiber) porous substrates can have a density of at least 15 g / m³. 2 20g / m 2 25g / m 2 30g / m 2 35g / m 2 40g / m 2 45g / m 2 Or 50g / m 2 The basis weight. (e.g., fiber) porous substrates typically have a basis weight of no more than 200 g / m³. 2 150g / m 2 Or 100g / m 2The basis weight. In some embodiments, the open area (which may be determined by the basis weight and density of the material) is at least 10%, 20%, 30%, 40%, 50%, 60%, or 70%. The thickness of the porous substrate (e.g., fiber) is typically at least 0.05 mm (50 micrometers), 0.10 mm (100 micrometers), or 0.15 mm (150 micrometers). In some embodiments, the thickness of the substrate (e.g., fiber) is not greater than 0.5 mm (500 micrometers), 0.4 mm, 0.3 mm, or 0.2 mm. The number of strands in the porous fiber substrate is typically at least 5 strands / inch, 10 strands / inch, 15 strands / inch, 20 strands / inch, or 25 strands / inch (2.54 cm). In some embodiments, the number of strands in the porous fiber substrate is not greater than 150 strands / inch, 100 strands / inch, 75 strands / inch, or 50 strands / inch (2.54 cm). The porous fiber substrate may be compressed during manufacturing, resulting in a greater basis weight and a smaller thickness in the article.

[0035] Exemplary porous fiber substrates are commercially available from industrial netting (e.g., WN0100 and WN0200), Bedford Weaving Inc., ANCI, and Tessitura A. Ghiringhelli & CSpA, Azzate, Italy. Some physical properties of exemplary fiber webs are as follows:

[0036] Manufacturing method

[0037] Methods of manufacturing adhesive articles typically involve providing a layer of polydiorganosiloxane composition (e.g., uncrosslinked or partially crosslinked) on a carrier (such as a release liner or an organic polymer film). The layer of polydiorganosiloxane composition also includes a porous substrate at a first main surface, at an opposing main surface, or embedded within the layer of the polydiorganosiloxane composition.

[0038] In some embodiments, a layer of a polydiorganosiloxane composition (e.g., uncrosslinked or partially crosslinked) is applied to a porous substrate, such as a fibrous web or an open-cell organic polymer membrane. This embodiment optionally includes forming pores through one or more crosslinked layers of the porous substrate and the unfunctionalized polydiorganosiloxane composition.

[0039] Alternatively, a layer of a polydiorganosiloxane composition (e.g., uncrosslinked or partially crosslinked) is applied to a nonporous substrate, such as an organic polymer membrane. The method also includes forming pores through one or more crosslinked layers of the nonfunctionalized polydiorganosiloxane composition via a fibrous web or organic membrane substrate.

[0040] In a typical implementation, the (e.g., porous) substrate is embedded within the polydiorganosiloxane composition, such as Figure 1 As depicted. This can be prepared by coating a release liner 140 with a first layer 120A of a polydiorganosiloxane composition (e.g., uncrosslinked or partially crosslinked), applying a (e.g., porous) substrate 180 to the first layer 120A, and coating a second layer 120B of the polydiorganosiloxane composition (e.g., uncrosslinked or partially crosslinked) to the (e.g., porous) substrate 180 (and the underlying layer 120A). It is also contemplated that the first layer 120A of the (e.g., uncrosslinked or partially crosslinked) polydiorganosiloxane composition may be at least partially crosslinked before the second layer 120B is applied. Figure 1 In this embodiment, a (e.g., porous) substrate 180 is depicted disposed in the middle of the total thickness of the polydiorganosiloxane composition (i.e., 120A together with 120B). In other words, approximately 50% by weight of the polydiorganosiloxane composition is disposed on both main surfaces of the (e.g., porous) substrate 180. However, the weight ratio of the polydiorganosiloxane composition of the first layer 120A to the second layer 120B can be changed from 9:1 to 1:9. In some embodiments, it is advantageous for the first layer 120A to be thicker than the second layer 120B. In this embodiment, the weight ratio of the polydiorganosiloxane composition of the first layer 120A to the second layer 120B can be greater than 1:1, such as 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, or 5:1.

[0041] In another embodiment, after the polydiorganosiloxane composition is applied to the release liner carrier 240, a (e.g., porous) substrate 280 is disposed on (e.g., uncrosslinked or partially crosslinked) polydiorganosiloxane composition 220, such as Figure 2 As illustrated. In one embodiment, the porous substrate may have a low porosity such that the polydiorganosiloxane composition 220 does not significantly permeate the porous substrate, thereby providing low viscosity at the first main surface 221. In this embodiment, the porous substrate may have less than 50%, 40%, 30%, 20%, or 10% open space.

[0042] In another embodiment, before providing the (e.g., uncrosslinked or partially crosslinked) polydiorganosiloxane composition 320 onto the release liner carrier, a (e.g., porous) substrate 380 is disposed on the release liner 380, such as... Figure 3As depicted. In this embodiment, the porous substrate is sufficiently porous that the polydiorganosiloxane composition permeates the porous substrate, thereby providing sufficient adhesion at the first primary surface 321. In one embodiment, the porous substrate typically has an open space of greater than 50%, 60%, or 70%. However, for pressure-wrapped articles, the porous substrate may have a lower amount of open space. In some embodiments, the porous substrate may first be coated with a low-viscosity polydiorganosiloxane (e.g., less than 100,000 centiliters (cSt)), and a higher viscosity (at least 500,000 or 1,000,000 centiliters) is applied to the coated porous substrate.

[0043] The polydiorganosiloxane composition has a layer having a first primary surface adjacent to a release liner carrier and an opposing second primary surface. The method includes subjecting the opposing second primary surface of the polydiorganosiloxane composition layer to radiation treatment, thereby crosslinking the polydiorganosiloxane composition layer.

[0044] An uncured polydiorganosiloxane composition can be applied to a release liner or (e.g., a porous) substrate, with no substrate on the opposing surface (“open surface”). Alternatively, the uncured polydiorganosiloxane composition and (e.g., a porous) substrate can be disposed between two release liners during curing. Generally, the chamber is inert (e.g., the oxygen-containing chamber air is replaced by an inert gas (e.g., nitrogen), and the sample is electron beam crosslinked, particularly when the open surface is crosslinked. In some embodiments, the polydiorganosiloxane composition crosslinks upon contact with a first release liner. After crosslinking, the pressure-sensitive adhesive surface is made accessible to a second release liner, and the first release liner is removed. In some embodiments, the method further includes winding the crosslinked layer of the polydiorganosiloxane composition into a roll (e.g., tape).

[0045] Various release liner types are known and commercially available. Release liner types may include a polyester terephthalate support film and a release coating. Other support films used for the release coating include polyolefins (e.g., polyethylene, polypropylene) and paper. In some embodiments, the release coating may be a fluorosilicone material. Release coatings free of silicone and / or fluorinated materials have also been described for use with polydiorganosiloxane adhesives.

[0046] Release liners are typically characterized as having light, medium, or heavy peel strength based on the peel force required to remove the pressure-sensitive adhesive from the adhesive article. This can be measured according to EN ISO 29862, Annex B (Self-adhesive tapes – Peel adhesion measured from a surface at a 90° angle) using an SP-2100 peel tester from IMass, Inc., equipped with a 10 lbf force sensor and a peel rate of 30 cm / min. When heavy peel strength is required, the peel force required to remove the pressure-sensitive adhesive from the adhesive article from the release liner can be at least 40 g / in (2.54 nm) or greater. When light peel strength is required, the peel force required to remove the pressure-sensitive adhesive from the adhesive article from the release liner can be less than 10 g / in or 5 g / in (2.54 nm). When medium peel strength is required, the peel force required to remove the pressure-sensitive adhesive from the adhesive article from the release liner can be greater than 10 g / in and less than 40 g / in (2.54 nm).

[0047] Various release liner products are commercially available, including release liner products purchased under the trade name "SILFLU" from Siliconature Spa (Godega di Sant'Urbano, Italy); and release liner products purchased under the trade name Cerapeel. ™ The stripping liner was purchased from Toray; the POLYSILK was from Loparex International BV (Apeldoorn, The Netherlands). ™ Silicone release liner; from 3M Company (St Paul, MN), Minnesota, USA. ™ Scotchpak ™ 9741 stripper gasket; and perfluorinated stripper chemicals as disclosed in US 4,472,480.

[0048] In a typical implementation, a thicker layer of the same polydiorganosiloxane composition is crosslinked from one side, thereby providing a crosslinking gradient, where one surface is a pressure-sensitive adhesive and the opposite surface is a film backing. When the opposite surfaces of the crosslinked polydiorganosiloxane composition are film backings, the article may not contain other film backing materials, such as polyurethane film backings.

[0049] However, it is also envisioned that the polydiorganosiloxane layer can be formed by coating more than one layer of the same polydiorganosiloxane composition. Furthermore, the polydiorganosiloxane composition can be subjected to more than one radiation treatment from both sides or (e.g., radiation treatment of different intensities).

[0050] The thickness and crosslinking conditions are selected such that a pressure-sensitive adhesive is formed on the first main surface (closer to the substrate), and a film backing is formed on the opposite second main surface (closer to the radiation energy source).

[0051] The total thickness of the polydiorganosiloxane layer is typically at least 250 micrometers. The thickness of the polydiorganosiloxane layer is typically no greater than 1000 micrometers, 900 micrometers, 800 micrometers, or 700 micrometers. In some embodiments, the thickness is no greater than 650 micrometers, 600 micrometers, 550 micrometers, 500 micrometers, 450 micrometers, 400 micrometers, 350 micrometers, 300 micrometers, or 250 micrometers.

[0052] In some embodiments, the polydiorganosiloxane composition can be crosslinked by treatment with electron beam irradiation. In some embodiments, the coating can be crosslinked by treatment with gamma radiation. In some embodiments, a combination of electron beam crosslinking and gamma-ray crosslinking can be used. For example, in some embodiments, the coating can be partially crosslinked by treatment with electron beam irradiation. Subsequently, the coating can be further crosslinked by gamma radiation.

[0053] Commercially available electron beam generating equipment is available, such as the CB-300 electron beam generator (available from Energy Sciences, Inc. (Wilmington, MA), also described in US 8,541,481). Commercially available gamma radiation equipment includes devices commonly used for gamma radiation sterilization of products intended for medical applications. In some embodiments, such equipment can be used to crosslink or partially crosslink the skin-friendly adhesives of this disclosure. In some embodiments, such crosslinking can occur simultaneously with the sterilization process of a semi-finished or finished product (e.g., tape or wound dressing).

[0054] In some embodiments, the polydiorganosiloxane material is subjected to electron beam radiation with a voltage of at least 200 kV, 250 kV, or 300 kV. The voltage of the electron beam radiation is typically no greater than 500 kV, 450 kV, 400 kV, 350 kV, or 300 kV. The total dose of the electron beam radiation is typically at least 2 MRad, 3 MRad, 4 MRad, 5 MRad, 6 MRad, 7 MRad, 8 MRad, 9 MRad, 10 MRad, 11 MRad, 12 MRad, 13 MRad, 14 MRad, or 15 MRad. In some embodiments, the total dose of the electron beam radiation is typically no greater than 25 MRad or 20 MRad. The intensity and total radiation exposure are based on the electron beam generating device and the duration of radiation exposure. It should be understood that in this invention, the first primary surface and the opposite second primary surface of the polydiorganosiloxane layer receive different doses of electron beam radiation.

[0055] Physical properties of cross-linked polydiorganosiloxane compositions

[0056] In some embodiments, the tack of the pressure-sensitive adhesive on the first main surface is at least 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L, 55 g / L, 60 g / L, 65 g / L, 70 g / L, 75 g / L, or 80 g / L. In some embodiments, the tack of the pressure-sensitive adhesive on the first main surface is not greater than 120 g / L, 110 g / L, or 100 g / L. In some embodiments, the tack of the pressure-sensitive adhesive on the first main surface is not greater than 75 g / L, 50 g / L, or 25 g / L. In some embodiments, the tack of the pressure-sensitive adhesive on the first main surface is not greater than 15 g / L, 10 g / L, or 5 g / L.

[0057] In some implementations, the adhesiveness of the membrane backing on the second primary surface is less than 30 g / L, 25 g / L, 20 g / L, 15 g / L, 10 g / L, or 5 g / L.

[0058] In some embodiments, the pressure-sensitive adhesive on the first main surface has greater tack than the membrane backing on the second main surface. The difference in tack can be at least 25 g / L, 50 g / L, 75 g / L, 100 g / L, 150 g / L, or greater. In other embodiments, the pressure-sensitive adhesive on the first main surface has substantially the same tack as the membrane backing on the second main surface (i.e., within 10% of the average tack value).

[0059] In some embodiments, the crosslinked polydiorganosiloxane layer has a tensile modulus of at least 0.10 N / inch, 0.15 N / inch, or 0.2 N / inch (2.54 cm). In some embodiments, the crosslinked polydiorganosiloxane layer has a tensile modulus of no more than 0.4 N / inch, 0.3 N / inch, or 0.2 N / inch. In some embodiments, the crosslinked polydiorganosiloxane layer has a maximum tensile strength of at least 1 N / inch, 1.5 N / inch, 2 N / inch, or 2.5 N / inch (2.54 cm). In some embodiments, the crosslinked polydiorganosiloxane layer has a maximum tensile strength of no more than 4 N / inch, 4.5 N / inch, 3 N / inch, 3.5 N / inch, or 2 N / inch. In some embodiments, the crosslinked polydiorganosiloxane layer has a maximum elongation of at least 100%, 150%, 200%, or 350%. In some embodiments, the cross-linked polydiorganosiloxane layer has a maximum elongation of no more than 500%, 400%, or 300%.

[0060] Peel adhesion to biological substrates such as human skin is known to be highly variable. Skin type, location on the body, and other factors can affect the results. Typically, the average peel adhesion to skin exhibits a large standard deviation. In some embodiments, the average peel adhesion to human skin can be less than 200 gm / 2.54 cm, and in some embodiments, less than 100 gm / 2.54 cm.

[0061] Products

[0062] In many embodiments, (e.g., medical) adhesive articles comprise a crosslinked layer of a polydiorganosiloxane composition having two main surfaces—a first main surface (proximity to the release liner during manufacturing) comprising a pressure-sensitive adhesive and a second main surface comprising a membrane backing. Both the pressure-sensitive adhesive and the membrane backing comprise the same polydiorganosiloxane composition, but the membrane backing comprises a larger crosslinking than the pressure-sensitive adhesive.

[0063] In some implementations, the second peeling liner contacts the surface of the membrane backing.

[0064] In another embodiment, the adhesive (e.g., tape) article may comprise a cross-linked layer of a polydiorganosiloxane composition without a release liner. The adhesive (e.g., tape) article may be wound in a roll such that the backing surface is in contact with the pressure-sensitive adhesive surface.

[0065] In some embodiments, the cross-linked layer of the polydiorganosiloxane composition is suitable for medical articles such as medical tapes, bandages, wound dressings, IV site dressings, pressure bandages, surgical drapes, prostheses, ostomy or ostomy bags, oral patches, or transdermal patches. In some embodiments, the cross-linked layer of the polydiorganosiloxane composition can also be used in other articles, including dentures and wigs.

[0066] In some embodiments, the cross-linked layer of the polydiorganosiloxane composition is suitable for contact with the skin or other tissues of humans and / or animals.

[0067] Additional components

[0068] (For example, medical) adhesive articles may include a variety of additional components known in the art. Such additional components are optional with respect to the most broad embodiments of the invention, but may be preferred for some medical articles.

[0069] In some embodiments, when the adhesive article is a wound dressing, the article may also include an absorbent pad, such as that described in US2019 / 0231604; which is incorporated herein by reference.

[0070] Absorbent pads are typically positioned at the center of the surface of a pressure-sensitive adhesive, such that adhesive or pressure-sensitive adhesive is present on the opposite sides surrounding the absorbent pad.

[0071] The absorbent pad may be made of one or more layers, and each layer may be made of one or more absorbent materials. Preferably, the absorbent pad is relatively flexible. Flexibility allows the medical product incorporating the absorbent pad to be easily applied to flexible parts of the body, such as joints. The absorbent pad may be cut at one or more locations to provide additional flexibility. In some embodiments, the absorbent pad may be translucent or transparent, thus allowing visual inspection of the wound without removing the wound dressing.

[0072] Absorbent pads may be made of synthetic or natural materials and may include, but are not limited to, woven or nonwoven materials (e.g., woven or nonwoven cotton or rayon), hydrocolloids (e.g., pectin, gelatin, carboxymethyl cellulose (CMC), crosslinked carboxymethyl cellulose (X-link CMC), crosslinked polyacrylic acid (PAA), and hydrocolloids described in U.S. Patents 5,622,711 and 5,633,010), polymeric gels (e.g., hydrogels), foams, collagen, hydrocellulose, alginate, and combinations thereof. In some embodiments, the absorbent pad may comprise polymeric fabrics, polymeric foams, and combinations thereof. For example, the polymeric fabric may be a nonwoven fabric, and the polymeric foam may be a foam used in TEGADEM foam adhesive dressings, which are available from 3M Company, St. Paul, Minn. In some embodiments, the polymeric foam is a polyurethane foam. The absorbent pad may optionally include other components, including one or more active agents, such as pharmacologically active agents, as further described in US2019 / 0231604.

[0073] Example

[0074] Except for Examples 7 and 16, 100% silicone oil A was used as the polydiorganosiloxane composition in all examples. The polydiorganosiloxane composition of Example 7 contained 94% by weight of silicone oil A and 6% by weight of silicone tackifying resin. The polydiorganosiloxane composition of Example 16 contained 100% silicone oil B. The polydiorganosiloxane compositions were coated onto release liner (including a 50-micron polyethylene terephthalate film with a release coating) using the various methods described below.

[0075] The following porous substrates are used in the embodiments: WN0100 and WN0200 are nylon meshes available from industrial weaving, with open areas of 38% and 44%, respectively.

[0076] Cellulose acetate fabrics are derived from Bedford and TAG, including high-density and low-density types from TAG.

[0077] Claf S8520FM is a cross-laminated polyolefin open network from ANCI, featuring an open area of ​​up to 70%, greater than any other porous substrate used. This large open area facilitates the formation of pores extending throughout the entire article via method 4 below.

[0078] Manufacturing of the embodiments in Table 1 : The polydiorganosiloxane composition is coated onto both sides of a porous substrate using one of the following methods: Method 1 - A layer of polydiorganosiloxane composition is applied to a release liner, a porous substrate is placed on top of the layer of polydiorganosiloxane composition, a second layer of polydiorganosiloxane composition is applied on top of the porous substrate, a second release liner is placed on top of the second polydiorganosiloxane layer, and the assembled layers are pressed between the release liner using a Carver press, wherein metal spacer spacers surround the edge of the press (Examples 1-2). Method 2 - A layer of the polydiorganosiloxane composition is applied to a release liner, a porous substrate is placed on top of the layer of the polydiorganosiloxane composition, a second layer of the polydiorganosiloxane composition is applied on top of the porous substrate, a second release liner is placed on top of the second polydiorganosiloxane layer, and the assembled layer is pulled through a doctor blade coater set to a 24 mil gap (Examples 3-7), or Method 3 - A layer of the polydiorganosiloxane composition is applied to a release liner by pulling it through a doctor blade coater set to an 8-mil gap, and two such polydiorganosiloxane layers are manually laminated, one polydiorganosiloxane layer on each side of the porous substrate (Examples 8-15).

[0079] Method 4 A layer of polydiorganosiloxane composition is applied to a release liner, a porous substrate is placed on top of the polydiorganosiloxane composition layer, a second layer of polydiorganosiloxane composition is applied on top of the porous substrate, a second release liner is placed on top of the second polydiorganosiloxane layer, and the assembled layers are laminated using a hand roller (e.g., manually). Then, both release liner pieces are removed, and the polydiorganosiloxane-coated porous substrate is transferred to a new set of release liner pieces, thereby leaving openings in the polydiorganosiloxane layer corresponding to the openings in the porous substrate (Example 16).

[0080] All embodiments were passed through an electron beam chamber at a voltage of 300 kV with the release liner facing upwards at the doses listed in Table 1. Thus, the layer of the polydiorganosiloxane composition was cured via the release liner.

[0081] After electron beam curing, Examples 1-2 were perforated using a mold designed to cut holes with a square pattern having a diameter of 2 mm and a center-to-center distance of 4.5 mm.

[0082] Probe viscosity test : Probe viscosity was tested using a texture analyzer (Stable Micro Systems). A hemispherical stainless steel probe with a radius of 6 mm was pushed into the sample at a speed of 1 mm / s until a force of 50 g was reached. The probe was removed from the sample at a speed of 0.1 mm / s, and the viscosity was recorded as the maximum force during removal, in grams. Measurements were taken on two main surfaces: the first main surface close to the release liner and the opposing second surface closest to the electron beam source during crosslinking.

[0083]

Claims

1. An adhesive article, said adhesive article comprising: A layer of a crosslinked, nonfunctionalized polydiorganosiloxane adhesive composition, the layer having a first primary surface, an opposing second primary surface, and a thickness of at least 250 micrometers; as well as A porous substrate, wherein the porous substrate is adjacent to the first main surface, adjacent to the second main surface, embedded within the layer, or a combination thereof.

2. The adhesive article according to claim 1, wherein the nonfunctionalized polydiorganosiloxane has the following formula: R1, R2, R3, and R4 are independently selected from alkyl and aryl groups, and each R5 is an alkyl group.

3. The adhesive article according to claim 2, wherein R5 is methyl.

4. The adhesive article according to claims 2 to 3, wherein R1, R2, R3 and R4 are methyl.

5. The adhesive article according to claims 1 to 4, wherein the polydiorganosiloxane adhesive composition is free of platinum group metal catalysts.

6. The adhesive article according to claims 1 to 5, wherein the polydiorganosiloxane composition has a viscosity of at least 50,000 mm before curing. 2 / s, 100,000mm 2 / s, 250,000mm 2 / s, 500,000mm 2 / s, 750,000mm 2 / s or 1,000,000mm 2 / s.

7. The adhesive article according to claims 1 to 6, wherein the layer of the crosslinked nonfunctionalized polydiorganosiloxane adhesive composition further comprises a tackifier.

8. The adhesive article according to claims 1 to 7, wherein the layers of the crosslinked nonfunctionalized polydiorganosiloxane composition comprise single or multiple layers of the same or different compositions.

9. The adhesive article according to claims 1 to 8, wherein the first primary surface is disposed on the release liner.

10. The adhesive article according to claim 9, wherein the pressure-sensitive adhesive on the first main surface has a tack of at least 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L.

11. The adhesive article according to claims 1 to 10, wherein the opposing second primary surface is a film backing.

12. The adhesive article of claim 11, wherein the tack of the film backing on the second main surface is less than 30 g / L, 25 g / L, 20 g / L, 15 g / L, 10 g / L or 5 g / L.

13. The adhesive article according to claims 1 to 12, wherein the porous substrate is a fiber web or an open-cell membrane.

14. The adhesive article according to claims 1 to 13, wherein the article comprises a plurality of pores extending through the porous substrate and a layer of the crosslinked nonfunctionalized polydiorganosiloxane adhesive composition.

15. An adhesive article comprising: A layer of a crosslinked, nonfunctionalized polydiorganosiloxane adhesive composition, the layer having a first primary surface and an opposing second primary surface; as well as An organic polymer film or fiber web, said organic polymer film or fiber web being adjacent to a first main surface, adjacent to a second main surface, embedded within said layer, or a combination thereof; wherein said article includes a plurality of pores extending through a layer of said organic polymer film or fiber web and a crosslinked nonfunctionalized polydiorganosiloxane adhesive composition.

16. The adhesive article according to claim 15, wherein the medical article is a medical tape, bandage, dressing, or pressure bandage.

17. A method for using an adhesive article, the method comprising providing the adhesive article according to claims 15 to 16 and contacting the pressure-sensitive adhesive with skin or a wound.

18. A method for manufacturing an adhesive article, the method comprising: a) Apply a layer of nonfunctionalized polydiorganosiloxane adhesive composition to a release liner carrier; b) Before or after applying the layer of the nonfunctionalized polydiorganosiloxane adhesive composition to the release liner carrier, a porous substrate is provided on the release liner carrier. c) Optionally, a second layer of nonfunctionalized polydiorganosiloxane adhesive is applied to the porous substrate, wherein the total thickness of the nonfunctionalized polydiorganosiloxane adhesive is at least 250 micrometers. d) subjecting one or more layers of the nonfunctionalized polydiorganosiloxane composition to radiation treatment, thereby crosslinking one or more layers of the polydiorganosiloxane composition.

19. The method of claim 18, further comprising forming pores through one or more crosslinked layers of the porous substrate and the nonfunctionalized polydiorganosiloxane composition.

20. A method for manufacturing an adhesive article, the method comprising: a) Applying a layer of nonfunctionalized polydiorganosiloxane adhesive composition between the release liner carrier and the organic polymer film or fiber web; c) Optionally, a second layer of nonfunctionalized polydiorganosiloxane adhesive is applied to the organic polymer film; d) subjecting one or more layers of the nonfunctionalized polydiorganosiloxane composition to radiation treatment, thereby crosslinking one or more layers of the polydiorganosiloxane composition; as well as Pores are formed through one or more cross-linked layers of the fiber web or organic membrane substrate and the nonfunctionalized polydiorganosiloxane composition.

21. The method according to claims 18 to 20, further characterized by the features defined in claims 2 to 16.

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