WO2008057155A1 - Silicone skin adhesive gels - Google Patents

Abstract

This invention pertains to silicone gel forming compositions that have an average RHAIk of 0.7 to 1.5, typically 0.8 to 0.95 and with an average RHCE of 0.4 to 1, typically 0.8 to 0.95 and the silicone gels produced by curing the gel forming composition. These gels are suitable for temporarily adhering a medical device to a biological substrate such as skin. The silicone gels provide high adhesion to skin and low peel release force from polyethylene substrate.

Description

SILICONE SKIN ADHESIVE GELS

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] NONE

BACKGROUND OF THE INVENTION

[0002] This invention relates to silicone gel compositions which have suitable adhesive performance to adhere temporary a medical device to a biological substrate such as skin. [0003] Pressure sensitive adhesives (PSAs), including silicone PSAs, and tapes containing such adhesives are known in the art and many are commercially available. Typically, silicone PSAs comprise condensed blends of silicone fluids and silicone resins. Typically, such silicone PSAs are applied as thin coatings between substrates to be adhered together. [0004] It is likewise known in the art to use silicone PSAs in medical applications. For instance, it is known to use silicone PSAs to adhere transdermal drug delivery devices and medical prosthesis to patients.

[0005] Silicone PSAs, however, can have a number of properties that limit their use in medical applications. For instance, the adhesive strength of silicone PSAs is often so great that a patient's skin or the object to be adhered can be damaged on removal of the PSA. Additionally, silicone PSAs often exhibit cold flow properties at skin temperature. As such, the resultant inflexible layers of PSA can be very uncomfortable on the patient's body.

[0006] Silicone gels are also known in the art. These gels have been used, for example, as dielectrics, vibration dampers and in medical therapy for cutaneous scars or injuries (e.g., abrasions, surgical areas or burns). In this latter use, the silicone gel is in the form of a sheet with one tacky surface for adherence to the patient's skin and one non-tacky surface to inhibit undesirable adhesion to the gel (e.g., the patient's clothing). Since the silicone gels are softer than PSAs, when they are applied to tissue such as skin, they have a skin-like texture that provides a less disruptive interface with the skin (e.g. it is more flexible). However, the silicone gels exhibit a lower adhesion to skin than silicone PSAs. [0007] Moreover, when silicone gels are joined with certain substrates such plastics, however, the adhesive strength between the silicone gel and the plastic is often so weak that it delaminates. As such, when the silicone gel is used as an adhesive to adhere a medical substrate to a human or animal body, the gel often delaminates from the plastic substrate before the gel delaminates from the human or animal body to which it is applied. [0008] To solve this problem, the art suggested treating the substrate such as plastic surface with means such as corona, flame, and plasma. While such treatments are beneficial, they are difficult to implement on a continuous coating line. Moreover, the treatments must be precisely controlled to prevent damages to the substrate (e.g., heat damage) or inhibit the cure of the silicone materials. A second approach to improve the adhesion to substrates, especially plastic substrates, is to use a primer material, such as a titanate material, on the substrate. This approach, however, requires additional processing steps. [0009] Several silicone based technologies allow for preparing silicone gels. The gels are generally formed from linear or branched silicones having reactive groups thereon. Such reactive groups undergo a cross-linking reaction during curing. A preferred cross-linking reaction includes the hydrosilylation reaction in which a silicone having an Si-H reactive group reacts with a silicone having an aliphatically unsaturated reactive group in the presence of a hydrosilylation catalyst.

[0010] Typical silicone gel forming compositions include alkenyl functional polyorganosiloxanes (e.g. vinyl functional polyorganosiloxanes), α,ω-hydrogen polyorganosiloxanes known as chain extenders, hydrogen functional polyorganosiloxanes known as cross-linkers, and a hydrosilylation catalyst (e.g. platinum complex). Such silicone gels forming compositions are often described using the following molar ratios:

RHAIk = (moles of silicon-bonded hydrogen in (B))/(moles of silicon-bonded alkenyl in (A))

RHV = (moles of silicon-bonded hydrogen in (B))/(moles of silicon-bonded vinyl in (A)) RH_CEV = (moles of silicon-bonded hydrogen from chain extenders)/ (moles of silicon-bonded vinyl)

RHc_E = (moles of silicon-bonded hydrogen from chain extenders)/(moles silicon- bonded hydrogen) BRIEF SUMMARY OF THE INVENTION

[0011] This invention pertains to silicone gel forming compositions that have an average RHAIk of 0.7 to 1.5, typically 0.8 to 0.95 and with an average RH_CE of 0.4 to 1, typically 0.8 to 0.95 and the silicone gels produced by curing the gel forming composition. These gels are suitable for temporarily adhering a medical device to a biological substrate such as skin. The silicone gels provide high adhesion to skin and low peel release force from polyethylene substrate. In particular, this invention also pertains to silicone gel comprising the catalyzed reaction product of (A) 55 wt% to 95 wt% of an alkenyl-substituted polydiorganosiloxane; (B) 1 to 30 wt% of an organosiloxane containing silicon-bonded hydrogen atoms; and (C) 0.005% to 2 wt% of a hydroxy functional siloxane resin and (D) at least one hydrosilylation catalyst wherein (A) and (B) are present to provide an average RHAIk of 0.7 to 1.5 and an average RH_CE of 0.4 to 1.

[0012] This invention also pertains to adhering the silicone gel to skin and to medical substrates such as plastics, natural macromolecular materials (e.g. collagen, wood, cork, and leather), metals, glass, ceramics or composites. [0013] The adhesion and physical properties of the silicone gels used in the present invention can be tailored to specific end uses by modifying the silicone gel forming compositions.

Because of the ease in removability and because the silicone gel generally maintains its tack after removal, the devices of the invention can be reused. In addition, the reusability allows for easy and comfortable repositioning of medical prosthesis. Finally, the silicone gels of this invention lack cold flow and, as such, are sufficiently soft to allow comfortable use by a human or animal.

DETAILED DESCRPTION OF THE INVENTION

[0014] As used herein, a "silicone gel" is a visco-elastic, jelly-like solid material formed by lightly cross-linking silicone polymers. [0015] The silicone gels are generally formed from linear or branched silicones having reactive groups thereon. Such reactive groups undergo a cross-linking reaction during curing. In particular for the silicone gels of the instant invention, the cross-linking reactions include the hydrosilylation reaction in which a silicone having an Si-H reactive group reacts with a silicone having an aliphatically unsaturated reactive group in the presence of a hydrosilylation catalyst. These materials are described, for example in US5656279, US5891076, EP0322118 and US4991574 which are incorporated herein by reference. The silicone gel used in the present invention should be chosen to have the properties desired for the end application. Important properties can include softness, flexibility and strength. [0016] The silicone gels are obtained by reacting a silicone gel forming composition comprising (A) at least one alkenyl-substituted polydiorganosiloxane, such as a polydimethylsiloxane having silicon-bonded alkenyl groups such as vinyl, allyl or hexenyl groups, (B) at least one organosiloxane containing silicon-bonded hydrogen atoms, (C) at least one hydroxy containing siloxane resin and (D) at least one catalyst for the reaction of the SiH groups with the Si-alkenyl groups, wherein (A) and (B) are present to provide an average RHAIk of 0.7 to 1.5 and an average RH_CE of 0.4 to 1. Such silicone gel forming compositions react at normal ambient temperatures, but the reaction can be expedited by exposure to elevated temperatures, e.g., from about 40⁰C to about 140⁰C. [0017] The alkenyl-substituted polydiorganosiloxanes (A) are known in the art as described, for example, in US patent number 3,983,298, herein incorporated by reference. Suitable alkenyl groups contain from 2 to about 6 carbon atoms and are exemplified by, but not limited to vinyl, allyl, and hexenyl. The alkenyl groups in this component may be located at terminal, pendant (non-terminal), or both terminal and pendant positions. The remaining silicon-bonded organic groups in (A) are independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups free of aliphatic unsaturation. These groups typically contain from 1 to about 20 carbon atoms, alternatively from 1 to 8 carbon atoms and are exemplified by, but not limited, to alkyl such as methyl, ethyl, propyl, and butyl; aryl such as phenyl; and halogenated alkyl such as 3,3,3- trifluoropropyl. Typically at least 50 percent of the organic groups in (A) are methyl. [0018] The structure of (A) is typically linear, however it may contain some branching due to the presence of trifunctional siloxane units. The viscosity (A) can be any desired. For example, it can be less than 100,000 mm²/second, alternatively less than 80,000 mm²/second, and alternatively 300 mm²/second - 3,000 mm²/second. It should be noted that additional alkenyl-substitution can be included in resin (C) as described below. [0019] Methods for preparing the alkenyl-substituted polydiorganosiloxanes (A) of the present invention, such as condensation of the corresponding halosilanes or equilibration of cyclic polydiorganosiloxanes, are well known in the art.

[0020] Component (A) can be used in the silicone gel forming composition in an amount of 55 wt% - 95 wt% based on the weight of the composition, alternatively 65 wt% - 90 wt%, alternatively 70 wt% - 85 wt%. The amount of alkenyl group present in (A) is typically between 0.02 wt% to 5 wt%, alternatively 0.05 wt% to 1 wt%, alternatively 0.08 wt% to 0.5 wt% alkenyl based on the weight of the alkenyl-substituted polydiorganosiloxane (A). [0021] Organosiloxanes containing silicon-bonded hydrogen atoms (B) are also known in the art as described, for example in US patent number 3,983,298, herein incorporated by reference. The hydrogen atoms in (B) may be located at terminal, pendant, or both terminal and pendant positions. The remaining silicon-bonded organic groups in (B) are independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups free of aliphatic unsaturation. These groups typically contain from 1 to about 20 carbon atoms, alternatively from 1 to 8 carbon atoms, and are exemplified by, but not limited to alkyl such as methyl, ethyl, propyl, and butyl; aryl such as phenyl; and halogenated alkyl such as 3,3,3-trifluoropropyl. Typically, at least 50 percent of the organic groups in (B) atoms are methyl.

[0022] The structure of (B) is typically linear; however it may contain some branching due to the presence of trifunctional siloxane units. The viscosity of (B) can be any desired. For example, it can be less than 100,000 mm²/second and, alternatively, 5 mm²/second - 500 mm /second.

[0023] Component (B) can be used in the silicone gel forming composition of this invention in an amount of 1 wt% - 30 wt% based on the weight of the composition, alternatively 5 wt% to 20 wt%, and alternatively 5 wt% - 15 wt%. Typically, the amount of hydrogen group present in (B) is between 0.03 wt% - 1.44 wt% based on the weight of the organosiloxane containing silicon-bonded hydrogen atoms (B). [0024] The organosiloxane containing silicon-bonded hydrogen atoms (B) are typically prepared by co-hydrolysis of the appropriate chlorosi lanes using methods that are known in the art. U.S. Patent No. 2,877,255 to Clark; Japanese Laid Open Patent Application (KOKAI) SHO 62(1987)-39660 to Mogi et al.; and U.S. Patent Nos. 5,446,185 and U.S. No. 5,493,040 to Cobb et al., which are all hereby incorporated by reference.

[0025] In the silicone gel forming composition the amounts of (A) and (B) are such that the molar ratio RHAIk is in the range of 0.7 to 1.5, typically 0.8 to 0.95. The molar ratio RH_CE is in the range of 0.4 to 1, typically 0.8 to 0.95. [0026] Component (B) may be a single or mixture of organosiloxanes containing silicon- bonded hydrogen. The organosiloxane containing silicon-bonded hydrogen functions as a chain extender when it contains 3 or more SiH groups in the molecule. When the molar ratio RH_CE is 1 there typically a single organosiloxane containing silicon-bonded hydrogen. When the molar ration RH_CE is less than 1 there is typically a blend of organosiloxanes containing silicon-bonded hydrogen: one that contains at least 3 SiH groups per molecule and one that contains 1 or 2 SiH groups per molecule. One skilled in the art would know how to select the organosiloxanes containing silicon-bonded hydrogen to produce the desired RH_CE- [0027] The hydrosilylation catalyst (D) promotes the addition reaction of (A) with (B). The hydrosilylation catalyst can be any of the well known hydrosilylation catalysts comprising a platinum group metal, a compound containing a platinum group metal, or a microencapsulated platinum group metal or compound containing same. These metals include platinum, rhodium, ruthenium, palladium, osmium and iridium. Platinum and platinum compounds are preferred catalysts based on their high activity level in hydrosilylation reactions. One class of platinum catalysts is the complexes of chloroplatinic acid with certain vinyl -containing organosiloxane compounds disclosed by Willig in U.S. Pat. No. 3,419,593, which is hereby incorporated by reference. A specific catalyst of this type is the reaction product of chloroplatinic acid and l,3-diethenyl-l,l,3,3-tetramethyldisiloxane. [0028] The hydrosilylation catalyst (D) is present in an amount sufficient to cure the composition of the present invention. Typically, the concentration of (D) is sufficient to provide from 0.1 to 500 ppm (part per million), alternatively from 1 to 100 ppm, alternatively from 1 to 50 parts per million of a platinum group metal, based on the combined weight of the other components in the gel formulation. [0029] The silicone gel forming composition of the present invention also contains at least one hydroxy-substituted siloxane resin (C). Component (C) increases the adhesion of the silicone gel to the medical substrate and the skin. The resins contain silicone-bonded hydroxyl groups ranging from about 0.01 up to 5 weight percent of the resin, alternatively from about 1 to about 5 wt% of the resin.

[0030] Component (C) comprises R3SiOi/2 units (M units) and Siθ4/2 units (Q units) wherein each R is independently a linear, branched or cyclic hydrocarbon group having 1-20 carbon atoms. R can be unsubstituted or substituted with halogen atoms. Each R can be identical or different, as desired. The hydrocarbon group of R can be exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, vinyl, hexenyl, 3,3,3-trifluoropropyl, chloromethyl, and decyl, cycloaliphatic groups such as cyclohexyl, aryl groups such as phenyl, tolyl, and xylyl, chlorophenyl, and aralkyl groups such as benzyl, styryl and alpha- methylstyryl. Alternatively, each R group is an independently selected alkyl or alkenyl group comprising 1 to 8 carbon atoms or aryl group comprising 6 to 9 carbon atoms. Alternatively, each R group is independently selected from methyl and vinyl. Typically substantially all of the R groups are methyl. Alternatively no more than 0.5% of all R groups have olefϊnic unsaturation.

[0031] If an alkenyl group is present in the resin (C), typically the wt% of R groups present as alkenyl groups is less than 10%, alternatively less than 5%. For example, if the resin (C) contains vinyl groups, typically they are present in an amount of less than 5 wt% of the resin solids, alternatively less than 2.5 wt% of the resin solids, alternatively 1.5 wt% - 2 wt% of the resin solids.

[0032] In resin (C) the R3SiOi_/2 and SiC>_4/2 units are bonded to each other to form a resinous network. The molar ratio of R3SiOi_/2 to SiC>_4/2 is from 0.6:1 to 4:1 (M:Q). Alternatively, the molar ratio of M:Q is from 0.6: 1 to 1.9: 1. Alternatively, the molar ratio of M:Q is from 0.6:1 to 1.0:1. The resins (C) can also contain triorganosiloxy units (T units), for example 0.5 to 1 triorganosiloxy group for every S1O4_/2 unit, alternatively 0.6 to 0.9 triorganosiloxy group for every SiC^«4_/2 unit. [0033] It should be noted that more than one resin could be included in silicone gel forming composition. In this case, at least one of the resins should have the silanol content, but by the same token, one could have the silanol capped so that there is substantially no silanol present. It should also be noted that other resins can be also added to the silicone gel forming composition of this invention. For example, organic resins could be added if desired. In one embodiment, for example, a vinyl-functional resin can be added. For example two resins can be included — the first resin having substantially all of the R groups methyl and the second resin having 3.5 to 4 mole % of the R groups vinyl and substantially all of the remaining R groups methyl. [0034] Resins (C) comprising R3SiOj_/2 units and SiC<4_/2 units are well known in the art.

These copolymers are described, for example, in U.S. Pat. Nos. 3,936,582, 2,676,182, and 2,857,356. The resinous copolymers can be prepared by cohydrolysis of a mixture of si lanes having four hydrolyzable groups, e.g., silicon tetrachloride, and triorganosilanes having one hydrolyzable group, e.g., trimethylchlorosilane, in the proper ratio. A specific method for the preparation of these resinous copolymers is described in U.S. Pat. No. 2,676,182, wherein a silica hydrosol is reacted under acidic conditions with a source of triorganosiloxy units such as a hexaorganodisiloxane, for example, hexamethyldisiloxane, or a hydrolyzable triorganosilane, for example, trimethylchlorosilane, or mixtures thereof. [0035] Resin (C) can be used in the gel composition of this invention in an amount of 0.005% to 2 wt% based on the weight of the gel composition (components (A) - (D)), alternatively 0.01 t0 1.5 wt %.

[0036] If desired, other components can be included in the silicone gel forming composition of the present invention including, but not limited to, fillers, pigments, low temperature cure inhibitors, additives for improving adhesion, cross-linkers (e.g. Si-H cross-linkers), chain extenders, pharmaceutical agents, cosmetic agents, natural extracts, fluids or other materials conventionally used in gels.

[0037] Other optional components include silicone fluids, silicone waxes, silicone polyethers, and other polymers including, for example, hydrophilic polymers such as sodium polyacrylic acid, PVA, PVP, polyacrylic adhesive, cellulose and polysaccharide (which can make the gel more hydrophilic and more permeable to moisture). [0038] Still other optional components include rheology modifers such as thickening agents, thixotropic agents and materials that react with the ingredients of the gel such as castor oil or maleates that can react with the hydroxyl groups of the resin.

[0039] Typically the silicone gel forming composition (and hence the silicone gel) contains substantially no filler (e.g., less than 5 wt.%, alternatively less than 1 wt. %, alternatively les than 0.1 wt. %). Typically, the silicone gel forming composition contains substantially no solvent (e.g., less than 5 wt.%, alternatively less than 1 wt. %, alternatively less than 0.1 wt. %). [0040] The silicone gel forming composition of the present invention can be made by mixing the components in the desired ratio. It can be pre-compounded and supplied in multi-part system, typically as a two-part A & B system. This can be done in conventional mixing equipment. When used the various parts can be mixed in conventional mixing equipment including static mixer, prior application. The silicone gel forming compositions react at normal ambient temperatures, but the reaction can be expedited by exposure to elevated temperatures, e.g., from about 40⁰C to about 140⁰C

[0041] The consistency, strength, softness and tackiness of the silicone gel is determined by a number of factors including the ratio of reactive groups in the materials, the viscosity of the polymers, the quantity of ingredients including resin and the like. [0042] As measured by the Cone Penetration Test method based on ASTM D-217-88, the silicone gels typically have a penetration of 50 mm to 250 mm with a cone category 1806-1 weighted 62.5 g. Generally, the gels have a coating weight in the range of about 100 g/m² to 4500 g/m². Typically, the densities are in the range of about 150 g/m² to 1200 g/m². Such silicone gels would generally have thicknesses in the range of about 0.15 mm to about 5 mm, typically the gels have a thickness of 0.2 mm to 1.5 mm. [0043] The adhesive strength of the silicone gels should be sufficient to maintain adhesion to the medical substrate. Similarly, if the gel is to be adhered to a human or animal, the adhesive strength of the gel should be sufficient to ensure that it remains attached to the human or animal and yet not so strong that the human or animal is not excessively damaged when the gel is removed. As noted above, traditional silicone gels often do not adhere well to certain substrates such as plastics and, thus, delaminate. As such, the applicants herein have discovered that by adding a hydroxy-substituted siloxane resin to the silicone gel, the adhesive strength of the silicone gel to the plastic substrate is increased. [0044] When measured with a Probe Tack Tester, the tack of the silicone gel is generally between 50 g and 500 g, typically the tack is in the range of 150 g to 350 g. The adhesive property can also be measured using a texture analyzer (1/2 inch diameter cylinder Derlin probe, 100 gram force (gf) applied for 5 seconds and 10 mm/s separation speed). When measured by using a texture analyzer, the tack is generally between 50 gf to 500 gf. [0045] When used on a human or animal, the silicone gels should also be sufficiently soft and flexible to ensure comfort to the user. However, since softness also generally results in weaker gels, these two factors should be considered in selection and formulation of the gel. [0046] Additionally, an active agent may be formulated into the silicone gel forming composition and hence into the resulting gel. Active agents include any solid or liquid material that can be bound in the composition and subsequently released at the desired rate. The active agents should also not interfere with the reacting of the silicone gel forming composition to an unacceptable extent. Suitable active agents include cosmetics, personal care, cosmeceuticals, therapeutic or diagnostic materials, pesticides, herbicides, and the like. [0047] Therapeutic active agents which may be employed include, for example, antiacne agent, antibiotic, antiseptic, antifungal, antibacterial, antimicrobial, biocides, anti- inflammatory, astringents, hormones, anticancer agents, smoking cessation compositions, cardiovascular, histamine blocker, bronchodilator, analgesic, antiarrythmic, antihistamine, ^• alpha- I blocker, beta blocker, ACE inhibitor, diuretic, antiaggregant, sedative, tranquillizer, anticonvulsant, anticoagulant agents, vitamins, antiaging agents, agents for treating gastric and duodenal ulcers, anticellulites, proteolytic enzymes, healing factors, cell growth nutrients, peptides and others. Specific examples of suitable therapeutic active agents include silver and derivatives (for example silver ion, nanosilver), penicillins, cephalosporins, tetracyclines, macrolides, epinephrine, amphetamines, aspirin, acetominophen, barbiturates, catecholamines, benzodiazepine, thiopental, codeine, morphine, procaine, lidocaine, benzocaine, sulphonamides, ticonazole, perbuterol, furosamide, prazosin, prostaglandins, salbutamol, indomethicane, diclofenac, glafenine, dipyridamole, theophylline and retinol. [0048] In addition to the therapeutic or diagnostic materials, active, agents could be cosmetics such as perfumes, UV protectors, shaving products, deodorants or the like. Suitable cosmetics are known to those skilled in the art.

[0049] Some additional examples of the cosmetics, personal care, and cosmeceutical ingredients and pharmaceutical excipients that may be used herein may be found in the CTFA ingredient Database and the handbook of pharmaceutical excipients and can include, for example, absorbents, anticacking agents, antioxidants, antistatic agents, astringents, binders, buffering agents, bulking agents, chelating agents, colorants, cosmetic astringents, cosmetic biocides, deodorant agents, emollients, external analgesics, film formers, flavoring agents, fragrance ingredients, humectants, lytic agents, moisturizing agents, occlusivity enhancers, opacifying agents, oxidizing and reducing agents, penetration enhancers, pesticides, plasticizers, preservatives, skin bleaching agents, skin conditioning agents, skin protectants, slip modifiers, solubilizing agents, solvents, sunscreen agents, surface modifiers, surfactants and emulsifying agents, suspending agents, thickening agents, viscosity controlling agents including increasing or decreasing agents, and UV light absorbers.

[0050] Cosmetic, personal care and cosmeceutical ingredients, and pharmaceutical excipients which may be employed are selected, for example, from the following chemical classes: alcohols, fatty alcohols and polyols, aldehydes, alkanolamines, alkoxylated alcohols (e.g. polyethylene glygol derivatives of alcohols and fatty alcohols), alkoxylated amides, alkoxylated amines, alkoxylated carboxylic acids, amides including salts (e.g. ceramides), amines, amino acids including salts and alkyl substituted derivatives, esters, alkyl substituted and acyl derivatives, polyacrylic acids, acrylamide copolymers, adipic acid copolymers, alcohols, aminosilicones, biological polymers and derivatives, butylene copolymers, carbohydrates (e.g. polysaccharides, chitosan and derivatives), carboxylic acids, carbomers, esters, ethers and polymeric ethers (e.g. PEG derivatives, PPG derivatives), glyceryl esters and derivatives, halogen compounds, heterocyclic compounds including salts, hydrophilic colloids and derivatives including salts and gums (e.g. cellulose derivatives, gelatin, xanthan gum, natural gums), plant extracts and their derivatives such as Arnica (e.g. Arnica montana), Myrrh (e.g. Commiphora myrrha), Ginkgo (e.g. Ginkgo biloba), Calendula (e.g. Calendula officinalis), Chamomile (e.g. Matricaria chamomilla, Matricaria recutita), Sophore (e.g. Sophora japonica), Thyme (e.g. Thymus vulgaris), Red Vine (e.g Vitis Vinifera), Witch Hazel (e.g. Hamamelis virginiana), Aloe (e.g. Aloe Vera, Aloe barbadensis), Licorice (e.g. Glycyrrhiza glabra, Glycyrrhiza uralensis), Tea Tree (e.g. Melaleuca alternifolia), Chickweed (e.g. Stellaria media), Cayenne (e.g. Capsicum frutescens, capsicum annuum), Horse Chestnut (e.g. Aesculus hippocastanum), Comfrey (e.g. Symphytum officinale ), Cat's Claw (e.g. Uncaria tomentosa), St. John's Wort (e.g. Hypericum perforatum), Peruvian Balsam (e.g. Balsamum peruvianum), Plantain (e.g. Plantago major), Eucalyptus (e.g. Eucalyptus cinerea, globulus), Burdock(e.g. Arctium lappa), Poplar bud (e.g. Populi gemma), Gotu Kola (e.g. Centella asiatica, Hydrocotyle asiatica), Sweet Clover(Meliloti herba), Butcher's Broom (Ruscus aculeatus), Oak Bark (e.g. Quercus robur), Oats (e.g. Avena sativa), Fir (e.g. Abies sibirica Ledeb), Dandelion (e.g. Taraxacum officinale Wigg), Sage (e.g. Salvia officinalis), Elecampane (e.g. Inula helenium), Celandine (e.g. Chelidonium majus), Oregon Mountain Grape (e.g. Berberis aquifolium), Barberry (e.g. Berberis vulgaris), Heartsease (e.g. Viola tricolor), Borace (e.g. Borago officinalis), Lemon Balm (e.g. Melissa officinalis), Elderberry (e.g. Sambucus nigra), Yarrow (e.g. Achillea millefolium), essential oils such as Citrus oil, Minth oil, Cypress oil, Sage oil, Lavender oil, Lavender oil, Thyme oil, Juniper oil, Verbena oil, Cypress oil, Ylang-Ylang oil, Sweet Almond oil (e.g. Prunus amygdales), Apricot kernel (e.g. Punus Armeniaca), Avocado oil (e.g. Persea Americana), Borage oil (e.g. Borago officinalis), Castor oil (e.g. Ricinus communis), Coconut oil (e.g. Cocos nucifera), Cottonseed oil (e.g. Gossypium hyrsutum barbadense), Evening primrose (e.g. Oenothera biennis), Grape seed oil (e.g. Vitis vinifera), Hazelnut oil (e.g. Corylus avellana), Hemp seed oil (e.g. Cannabis sativa), Jojoba oil (e.g. Simmondsia chinensis), Kukui nut oil (e.g. Aleurites moluccana), Madacamia nut (e.g. Madacamia integrifolia), Need oil (e.g. Madhucca latifolia), Olive oil (e.g. Olea europaea), Palm oil (e.g. Elaesis guineesis), Peanut oil (e.g. Arachis hyupogae), Rose hip seed oil (e.g. Rosa mosqueta), Safflower (e.g. Carthamus tinctorius), Sesame oil (e.g. Sesamum inducum), Soybean oil (e.g. Soya max), Sunflower oil (e.g. Helianthus annuus), Wheat germ oil (e.g. Triticum vulgare), propolis, imidazolines, inorganic materials (clay, TiO2, ZnO), ketones (e.g. camphor), isethionates, lanolin and derivatives, organic salts, phenols including salts (e.g. parabens), phosphorus compounds (e.g. phosphate derivatives), polyacrylates and acrylate copolymers, protein and enzymes derivatives (e.g. collagen), synthetic polymers including salts, siloxanes and silanes, sorbitan derivatives, sterols, sulfonic acids and derivatives and waxes. [0051] Some examples of antiacne agents are Salicylic acid and Sulfur. Some examples of antifungal agents are Calcium Undecylenate, Undecylenic Acid, Zinc Undecylenate, and Povidone-Iodine. Some examples of antimicrobial agents are Alcohol, Benzalkonium Chloride, Benzethonium Chloride, Hydrogen Peroxide, Methylbenzethonium Chloride, Phenol, Poloxamer 188, and Povidone-Iodine. Some examples of antioxidants are Acetyl Cysteine, Arbutin, Ascorbic Acid, Ascorbic Acid Polypeptide, Ascorbyl Dipalmitate, Ascorbyl Methylsilanol Pectinate, Ascorbyl Palmitate, Ascorbyl Stearate, BHA, p- Hydroxyanisole, BHT, t-Butyl Hydroquinone, Caffeic Acid, Camellia Sinensis Oil, Chitosan Ascorbate, Chitosan Glycolate, Chitosan Salicylate, Chlorogenic Acids, Cysteine, Cysteine HCI, Decyl Mercaptomethylimidazole, Erythorbic Acid, Diamylhydroquinone, Di-t-

Butylhydroquinone, Dicetyl Thiodipropionate, Dicyclopentadiene/t-Butylcresol Copolymer, Digalloyl Trioleate, Dilauryl Thiodipropionate, Dimyristyl Thiodipropionate, Dioleyl Tocopheryl Methylsilanol, Isoquercitrin, Diosmine, Disodium Ascorbyl Sulfate, Disodium Rutinyl Disulfate, Distearyl Thiodipropionate, Ditridecyl Thiodipropionate, Dodecyl Gallate, Ethyl Ferulate, Ferulic Acid, Hydroquinone, Hydroxylamine HCI, Hydroxylamine Sulfate, lsooctyl Thioglycolate, Kojic Acid, Madecassicoside, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Melatonin, Methoxy-PEG-7 Rutinyl Succinate, Methylene Di-t- Butylcresol, Methylsilanol Ascorbate, Nordihydroguaiaretic Acid, Octyl Gallate, Phenylthioglycolic Acid, Phloroglucinol, Potassium Ascorbyl Tocopheryl Phosphate, Thiodiglycolamide, Potassium Sulfite, Propyl Gallate, Rosmarinic Acid, Rutin, Sodium

Ascorbate, Sodium Ascorbyl/Cholesteryl Phosphate, Sodium Bisulfite, Sodium Erythorbate, Sodium Metabisulfide, Sodium Sulfite, Sodium Thioglycolate, Sorbityl Furfural, Tea Tree (Melaleuca Aftemifolia) Oil, Tocopheryl Acetate, Tetrahexyldecyl Ascorbate, Tetrahydrodiferuloylmethane, Tocopheryl Linoleate/Oleate, Thiodiglycol, Tocopheryl Succinate, Thiodiglycolic Acid, Thioglycolic Acid, Thiolactic Acid, Thiosalicylic Acid, Thiotaurine, Retinol, Tocophereth-5, Tocophereth-10, Tocophereth-12, Tocophereth-18, Tocophereth-50, Tocopherol, Tocophersolan, Tocopheryl Linoleate, Tocopheryl Nicotinate, Tocoquinone, o-Tolyl Biguanide, Tris(Nonylphenyl) Phosphite, Ubiquinone, and Zinc Dibutyldithiocarbamate. Some examples of cosmetic biocides are Aluminum Phenolsulfonate, Ammonium Phenolsulfonate, Bakuchiol, Benzalkonium Bromide, Benzalkonium Cetyl Phosphate, Benzalkonium Chloride, Benzalkonium Saccharinate, Benzethonium Chloride, Potassium Phenoxide, Benzoxiquine, Benzoxonium Chloride, Bispyrithione, Boric Acid, Bromochlorophene, Camphor Benzalkonium Methosulfate, Captan, Cetalkonium Chloride, Cetearalkonium Bromide, Cetethyldimonium Bromide, Cetrimonium Bromide, Cetrimonium Chloride, Cetrimonium Methosulfate, Cetrimonium Saccharinate, Cetrimonium Tosylate, Cetylpyridinium Chloride, Chloramine T, Chlorhexidine, Chlorhexidine Diacetate, Chlorhexidine Digluconate, Chlorhexidine Dihydrochloride, p-Chloro-m-Cresol, Chlorophene, p-Chlorophenol, Chlorothymol, Chloroxylenol, Chlorphenesin, Ciclopirox Olamine, Climbazole, Cloflucarban, Clotrimazole, Coal Tar, Colloidal Sulfur, o-Cymen-5-ol, Dequalinium Acetate, Dequalinium Chloride, Dibromopropamidine Diisethionate, Dichlorobenzyl Alcohol, Dichlorophene,

Dichlorophenyl Imidazoldioxolan, Dichloro-m-Xylenol, Diiodomethyltolylsulfone, Dimethylol Ethylene Thiourea, Diphenylmethyl Piperazinylbenzimidazole, Domiphen Bromide, 7-Ethylbicyclooxazolidine, Fluorosalan, Formaldehyde, Glutaral, Hexachlorophene, Hexamidine, Hexamidine Diisethionate, Hexamidine Diparaben, Hexamidine Paraben, Hexetidine, Hydrogen Peroxide, Hydroxymethyl

Dioxoazabicyclooctane, Ichthammol, Isopropyl Cresol, Lapyrium Chloride, Lauralkonium Bromide, Lauralkonium Chloride, Laurtrimonium Bromide, Laurtrimonium Chloride, Laurtrimonium Trichlorophenoxide, Lauryl Isoquinolinium Bromide, Lauryl Isoquinolinium Saccharinate, Laurylpyridinium Chloride, Mercuric Oxide, Methenamine, Methenammonium Chloride, Methylbenzethonium Chloride, Myristalkonium Chloride, Myristalkonium Saccharinate, Myrtrimonium Bromide, Nonoxynol-9 Iodine, Nonoxynol-12 Iodine, Olealkonium Chloride, Oxyquinoline, Oxyquinoline Benzoate, Oxyquinoline Sulfate, PEG-2 Coco-Benzonium Chloride, PEG-10 Coco-Benzonium Chloride, PEG-6 Undecylenate, PEG- 8 Undecylenate, Phenol, o-Phenylphenol, Phenyl Salicylate, Piroctone Olamine, Sulfosuccinylundecylenate, Potassium o-Phenylphenate, Potassium Salicylate, Potassium Troclosene, Propionic Acid, PVP-Iodine, Quaternium-8, Quatemium-14, Quaternium-24, Sodium Phenolsulfonate, Sodium Phenoxide, Sodium o-Phenylphenate, Sodium Shale Oil Sulfonate, Sodium Usnate, Thiabendazole, 2,2'-Thiobis(4-Chlorophenol), Thiram, Triacetin, Triclocarban, Triclosan, Trioctyldodecyl Borate, Undecylenamidopropylamine Oxide, Undecyleneth?6, Undecylenic Acid, Zinc Acetate, Zinc Aspartate, Zinc Borate, Zinc

Chloride, Zinc Citrate, Zinc Cysteinate, Zinc Dibutyldithiocarbamate, Zinc Gluconate, Zinc Glutamate, Zinc Lactate, Zinc Phenolsulfonate, Zinc Pyrithione, Zinc Sulfate, and Zinc Undecylenate. Some examples of external analgesics are Benzyl Alcohol, Capsicum Oleoresin (Capsicum Frutescens Oleoresin), Methyl Salicylate, Camphor, Phenol, Capsaicin, Juniper Tar (Juniperus Oxycedrus Tar), Phenolate Sodium (Sodium Phenoxide), Capsicum (Capsicum Frutescens), Menthol, Resorcinol, Methyl Nicotinate, and Turpentine Oil (Turpentine). Some examples of oxidizing agents are Ammonium Persulfate, Calcium Peroxide, Hydrogen Peroxide, Magnesium Peroxide, Melamine Peroxide, Potassium Bromate, Potassium Caroate, Potassium Chlorate, Potassium Persulfate, Sodium Bromate, Sodium Carbonate Peroxide, Sodium Chlorate, Sodium Iodate, Sodium Perborate, Sodium Persulfate, Strontium Dioxide, Strontium Peroxide, Urea Peroxide, and Zinc Peroxide. Some examples of reducing agents are Ammonium Bisufϊte, Ammonium Sulfite, Ammonium Thioglycolate, Ammonium Thiolactate, Cystemaine HCl, Cystein, Cysteine HCl, Ethanolamine Thioglycolate, Glutathione, Glyceryl Thioglycolate, Glyceryl Thioproprionate, Hydroquinone, p-Hydroxyanisole, Isooctyl Thioglycolate, Magnesium Thioglycolate, Mercaptopropionic Acid, Potassium Metabisulfite, Potassium Sulfite, Potassium

Thioglycolate, Sodium Bisulfite, Sodium Hydrosulfite, Sodium Hydroxymethane Sulfonate, Sodium Metabisulfite, Sodium Sulfite, Sodium Thioglycolate, Strontium Thioglycolate, Superoxide Dismutase, Thioglycerin, Thioglycolic Acid, Thiolactic Acid, Thiosalicylic Acid, and Zinc Formaldehyde Sulfoxylate. An example of a skin bleaching agent is Hydroquinone. Some examples of skin protectants are Allantoin, Aluminum Acetate, Aluminum Hydroxide, Aluminum Sulfate, Calamine, Cocoa Butter, Cod Liver Oil, Colloidal Oatmeal, Dimethicone, Glycerin, Kaolin, Lanolin, Mineral Oil, Petrolatum, Shark Liver Oil, Sodium Bicarbonate, Talc, Witch Hazel, Zinc Acetate, Zinc Carbonate, and Zinc Oxide. Some examples of sunscreen agents are Aminobenzoic Acid, Cinoxate, Diethanolamine Methoxycinnamate, Digalloyl Trioleate, Dioxybenzone, Ethyl 4-[bis(Hydroxypropyl)] Aminobenzoate, Glyceryl Aminobenzoate, Homosalate, Lawsone with Dihydroxyacetone, Menthyl Anthranilate, Octocrylene, Octyl Methoxycinnamate, Octyl Salicylate, Oxybenzone, Padimate O, Phenylbenzimidazole Sulfonic Acid, Red Petrolatum, Sulisobenzone, Titanium Dioxide, and Trolamine Salicylate. Some examples of UV light absorbing agents are Acetaminosalol, Allatoin PABA, Benzalphthalide, Benzophenone, Benzophenone 1-12, 3-Benzylidene

Camphor, Benzylidenecamphor Hydrolyzed Collagen Sulfonamide, Benzylidene Camphor Sulfonic Acid, Benzyl Salicylate, Bornelone, Bumetriozole, Butyl

Methoxydibenzoylmethane, Butyl PABA, Ceria/Silica, Ceria/Silica Talc, Cinoxate, DEA- Methoxycinnamate, Dibenzoxazol Naphthalene, Di-t-Butyl Hydroxybenzylidene Camphor, Digalloyl Trioleate, Diisopropyl Methyl Cinnamate, Dimethyl PABA Ethyl Cetearyldimonium Tosylate, Dioctyl Butamido Triazone, Diphenyl Carbomethoxy Acetoxy Naphthopyran, Disodium Bisethylphenyl Tiamminotriazine Stilbenedisulfonate, Disodium Distyrylbiphenyl Triaminotriazine Stilbenedisulfonate, Disodium Distyrylbiphenyl Disulfonate, Drometrizole, Drometrizole Trisiloxane, Ethyl Dihydroxypropyl PABA, Ethyl Diisopropylcinnamate, Ethyl Methoxycinnamate, Ethyl PABA, Ethyl Urocanate, Etrocrylene Ferulic Acid, Glyceryl Octanoate Dimethoxycinnamate, Glyceryl PABA, Glycol Salicylate, Homosalate, Isoamyl p-Methoxycinnamate, Isopropylbenzyl Salicylate, Isopropyl Dibenzolylmethane, Isopropyl Methoxycinnamate, Menthyl Anthranilate, Menthyl Salicylate, 4-Methylbenzylidene, Camphor, Octocrylene, Octrizole, Octyl Dimethyl PABA, Octyl Methoxycinnamate, Octyl Salicylate, Octyl Triazone, PABA, PEG-25 PABA, Pentyl Dimethyl PABA, Phenylbenzimidazole Sulfonic Acid, Polyacrylamidomethyl Benzylidene Camphor, Potassium Methoxycinnamate, Potassium Phenylbenzimidazole Sulfonate, Red Petrolatum, Sodium Phenylbenzimidazole Sulfonate, Sodium Urocanate, TEA- Phenylbenzimidazole Sulfonate, TEA-Salicylate, Terephthalylidene Dicamphor Sulfonic Acid, Titanium Dioxide, TriPABA Panthenol, Urocanic Acid, and VA/Crotonates/Methacryloxybenzophenone-l Copolymer.

[0052] The silicone gels are useful for temporarily adhering a substrate of a medical device to a biological substrate such as skin. When used to adhere a medical substrate to a biological substrate, the silicone gel is typically used in the form of a gel layer. The gel layer can also be made by any desirable technique. One example comprises preforming the silicone gel (e.g., as a sheet) by known procedures e.g. by molding, calendering, extruding, spraying, brushing, applying by hand, coating or casting on, for example, a releasable substrate. The silicone gel is then brought together with the medical substrate. Alternatively, the silicone gel may be preformed (e.g., as a sheet) by casting and curing the gel-forming composition on the medical substrate. [0053] If desired, the surfaces of the silicone gels to be adhered to the medical substrate or the patient can be covered or protected with a release liner prior to use. The adhesive strength between the silicone gel and such release liner is obviously less than that between the gel and the substrate such that the release liner can be peeled off of the silicone gel revealing the underlying tacky gel. Suitable release liner materials are known in the art and can include, for instance, a plastic or multi-ply material such as a silicone, a fluorinated silicone, a fluorine polymer, polyethylene, polypropylene, polyethylene terephthalate (PET), ethylvinyl acetate polymer, PVC or the like. Additionally, the release liner could be made from a wide variety of materials (e.g., paper) coated with a suitable release coating. Finally, the surface of the release coating can be smooth, embossed or in any other desirable form. [0054] If the adhesive strength of the silicone gel is still not sufficient to adhere it to the medical substrate, either the surface of the silicone gel or the surface of the substrate can be primed. Suitable primers include titanate materials such as organic titanates commercialized by Dupont® under Tradename Tyzor® ; organic zirconate; hydrogen functional siloxanes such as dimethyl, methylhydrogen siloxane, trimethylsiloxy-terminated, methylhydrogen siloxane, trimethylsiloxy-terminated, dimethyl siloxane, hydrogen-terminated, and methylhydrogen cyclosiloxanes; and platinum derivatives such as 1,3-diethenyl-l, 1,3.3 - tetramethyldisiloxane complexes (platinum).

[0055] The silicone gel forming composition may be applied to the substrate by techniques such as spraying, coating, bar coating, etc. If desired, the gel forming composition can be used as a dispersion or solution in a volatile solvent such as an organic solvent, a low molecular weight silicone or other suitable solvent and, thereafter, the solvent can be evaporated and the reaction to produce the silicone gel is initiated. Alternative the silicone gel forming composition that does not require a substantial quantity of solvent, for example less than 5 wt. %, alternatively less than 1 wt. % can be used [0056] The silicone gel forming composition may be applied as a continuous layer, a perforated layer, or a discontinuous layer forming various designs such as lines, dots, circles, networks etc.

[0057] The substrate onto which the silicone gel forming composition is applied can be any surface that will impart the desired configuration to the compositions. Thus, it may be a continuous belt onto which the silicone gel forming composition is spread. Depending on the consistency of the silicone gel forming compositions, the substrate may have barriers at its edges to restrict the flow of the compositions until the reaction takes place. Typically, the substrate is a releasable substrate to allow the silicone gel to be easily removed and used. [0058] If desired, the substrate can be a preformed blister package made of any of the conventional blister packaging materials including, for example, polyvinyl chloride, polypropylene, polyethylene, polyester, paper or composites with or without suitable release coatings.

[0059] The silicone gel formed above can be any size and shape desired based on the final use. For instance, it can be circular, square or rectangular and it can vary from a few square centimeters to in excess of several hundred square cm. [0060] The silicone gels of the present invention are useful in applications where the adhesion provided by a silicone gel is useful, such adhering medical substrates on patients. Examples of such substrates include devices such as breast prosthesis, catheters, cannulas, drainage bags, uridomes, incontinence devices, hygiene napkins, pouches, false hairpieces (e.g., toupees), tubes, ostomy and related devices, surgery drapes, facial masks, gloves, other medical devices and the like. The silicone gels can be used for the manufacturing of silicone adhesive tapes (e.g. PU non-woven fabric with gel), gel sheeting (e.g. PU film with gel), wound dressings using silicone adhesives (e.g. PU film or PU foam with gel), bandages, adhesive strips, surgery drapes (PE film with gel), adhesive medical devices (e.g. PVC tube with gel, latex catheter with gel), hygiene napkins (PE film with gel), external prosthesis (e.g. PU external breast prosthesis with gel), topical or transdermal patches, fragrance/cosmetics patches, and the like.

[0061] Typical substrates to which the gel can be adhered comprise plastics or resins known in the art. Representative examples include polyolefins including polyethylenes (low density polyethylenes, high density polyethylenes and the like), polypropylenes, polybutylenes, polymethylpentenes, polyethylene-vinyl acetate (EVA) and their copolymers, polyvinyls, polyvinyl acetates, polyvinyl alcohol, polyvinylbutyral, polyvinyl formal, polyurethanes and polyurethane-ureas, polyvinyl chloride derivatives (polyvinyl chloride, polyvinylene chloride, copolyvinylchloride-propylene), polystyrenes and their copolymers (copolystyrene- butadiene, polystyrene acrylonitrile, polyacrylonitrile-butadiene-styrene), polyacrylic and polyacrylates derivatives (polymethyl methacrylate, ethylene/butyl acrylate copolymer, ethylene/methyl acrylate copolymer, ethylene/methacrylic acid copolymer), polyacrylonitrile, polyesters (including PETE, polyethylene terephtalate, polybutylene terephtalate, polyvinylacetate, polylactic-glycolic derivatives), cellulosic films (nitrocellulose, ethylcellulose, cellulose acetate, cellulose acetate butyrate, cellulose propionate), polyimides, polyamides (nylon), epoxy and phenolic plastics, silicone elastomers, polycarbonates, phenoplastes, fluorinated polymers (polytetrafluoroethylene, polyvinylidene fluoride), polyoxymethylenes, polyphenylene oxides, polysulfones (PSU, PESU, PPSU), polyphenyl sulfide, silicones and polysaccharide based materials. Typically the substrate is plastic and, alternatively, the plastic is polyurethane. [0062] The substrates used in the present invention can also be a continuous or perforated plastic film, a nonwoven film, a knitted fabric, a fiber network, a foam, a metal, a glass or ceramic material.

[0063] While the substrate can be in nearly any configuration, in one embodiment of the invention the substrate is in the form of a medical substrate. As used herein, a "medical substrate" is a substrate that is used in the treatment, maintenance or improvement of a human or animal. Such substrates can be used in combination with other materials for such purpose.

EXAMPLES [0064] The following examples are included to demonstrate embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention. All percentages are in wt. %.

Test Result were carried out as follows:

[0065] The viscosity before cure is recorded with a Brookfield viscometer. [0066] The softness in mm is recorded with a PNRG penetrometer with a 65mm diameter/62.5g cone probe. The sample is 80g to lOOg of adhesive gel cured at 103°C-140°C for 60 min in a plastic cup.

[0067] The tack in gf (gramforce) is recorded with a TA-XT Plus Texture Analyzer equipped with a probe P/0.5R (1/2" diameter Delrin cylinder). The sample is adhesive gel coated and cured on the appropriate substrate. Test parameters: test speed = 1.0 mm/s; force applied =

100 g; hold time = 5.0 s; trigger force = 1.0 g.

[0068] The peel adhesion in N (Newton) is recorded with a TA-XT Plus Texture Analyzer or

Tensile Testing equipment (e.g. Instron). The sample is adhesive gel coated and cured on the appropriate substrate, then cut in 2.5 cm strips, laminated to polyester film (Mylar). Test parameters: 180° peel release test, test speed = 10.0 mm/s, distance = 110.0 mm.

[0069] The polyurethane adhesion in N (Newton) is with a TA-XT Plus Texture Analyzer or

Tensile Testing equipment (e.g. Instron). The sample is prepared by coating silicone PSA such as 7-4602 on polyester (Mylar) using table top coater using shim size = 3 mil, covered with a suitable release liner, cut into strips (strip size = 1 inch wide X ~7 inches long). Then coat adhesive gel on polyurethane sheets using table top coater using shim size = 10 mil, cure and cover with polyethylene to protect adhesive, cut into strips (strip size = 1 inch wide X ~5 inches long), transfer the adhesive gel strip to the PSA strip minimizing air entrapment, use roller to adhere samples together, condition samples in oven for 20 minutes at 50⁰C, allowed samples to cool completely (minimum 10 minutes), test on Texture Analyzer using gel laminate adhesion test (180° peel test). Ran each sample in triplicate and reported the average force (N) and noted any observed characteristics.

[0070] The following materials were used in the preparation of silicone gels

[0071] Vinyl 400: A dimethylvinyl siloxy-terminated polydimethylsiloxane having a viscosity of 400 mPa.s containing 0.45 wt% vinyl.

[0072] Vinyl 2100: A dimethylvinyl siloxy-terminated polydimethylsiloxane having a viscosity of 2100 mPa.s containing 0.23 wt% vinyl.

[0073] Vinyl 9500: A dimethylvinyl siloxy-terminated polydimethylsiloxane having a viscosity of 9500 mPa.s containing 0.135 wt% vinyl. [0074] Vinyl 59600: A dimethylvinyl siloxy-terminated polydimethylsiloxane having a viscosity of 59600 mPa.s containing 0.086 wt% vinyl. [0075] MQ resin: a solid silicic acid, sodium salt, reaction products with chlorotrimethyl silane and iso-propyl alcohol containing 0 wt% vinyl and 2.0 - 2.5 wt% OH as SiOH.

[0076] Pt: 1,3-diethenyl-l, 1,3,3 -tetramethyldisiloxane platinum complex containing 0.5 w./w.% platinum and 2.27 w./w.% vinyl having a viscosity = 400 mPa.s. [0077] CE 15: A hydrogen-terminated polydimethylsiloxane having a viscosity of 15 mPa.s containing 0.137 wt% H as SiH.

[0078] CE 165 A hydrogen-terminated polydimethylsiloxane having a viscosity of 165 mPa.s containing 0.026 wt% H as SiH.

[0079] XL 5 : A trimethylsiloxy-terminated methylhydrogen polydimethylsiloxane having a viscosity of 5 mPa.s containing 0.784 wt% H as SiH.

[0080] XL 135 A trimethylsiloxy-terminated methylhydrogen polydimethylsiloxane having a viscosity of 135 mPa.s containing 0.116 wt% H as SiH

[0081] PDMS 12500: A trimethylsiloxy polydimethylsiloxane having a viscosity of 12500 mPa.s [0082] PDMS 1000: A trimethylsiloxy polydimethylsiloxane having a viscosity of 1000 mPa.s

[0083] PDMS 20: A trimethylsiloxy polydimethylsiloxane having a viscosity of 20 mPa.s

Examples 1-4 [0084] Silicone gel forming compositions were prepared by mixing together the polymer components in the amounts listed Table 1 and then adding the catalyst and mixing again. The blend was sampled in a cup for penetration testing and coating on polyurethane and polyester for adhesive performance testing after curing at 140⁰C for 6 min, the polyurethane laminates are cured at 120⁰C. Test results for the silicone gels are given in Table 2. Table 1: Formulations for Examples 1-4

Table 2: Test Results for Examples 1-4

Examples 5-8

[0085] Silicone gel forming compositions were prepared by mixing together the polymer components in the amounts listed Table 3 and thereafter adding the catalyst and mixing again. The blend was sampled in a cup for penetration testing and coating on polyurethane and polyester for adhesive performance testing after curing at 140⁰C for 6 min, the polyurethane laminates are cured at 120⁰C. Test results for the silicone gels are given in Table 4. Table 3: Formulations for Examples 5-8

Table 4: Test Results for Examples 5-8

Examples 9-13

[0086] Silicone gel forming compositions were prepared by mixing together the polymer components in the amounts listed Table 5 and thereafter adding the catalyst and mixing again. The blend was sampled in a cup for penetration testing and coating on polyurethane and polyester for adhesive performance testing after curing at 140⁰C for 6 min, the polyurethane laminates are cured at 120⁰C. Test results for the silicone gels are given in Table 6. Examples 9-13

Table 6: Test Results for Examples 9-13

Examples 14-18 [0087] Silicone gel forming compositions were prepared by mixing together the polymer components in the amounts listed Table 7 and thereafter adding the catalyst and mixing again. The blend was sampled in a cup for penetration testing and coating on polyurethane and polyester for adhesive performance testing after curing at 140⁰C for 6 min, the polyurethane laminates are cured at 120⁰C. Test results for the silicone gels are given in Table 8.

Table 7: Examples 14-18

Table 8: Test Results for Examples 14-18

Claims

That which is claimed is:

1. A silicone gel forming composition comprising:

(A) 55 to 95 wt% of at least one alkenyl-substituted polydiorganosiloxane; (B) 1 to 30 wt% of at least one organosiloxane containing silicon-bonded hydrogen atoms; and

(D) at least one hydrosilylation catalyst wherein (A) and (B) are present in amounts to provide an average RHAIk 0.7 to 1.5 and an average RH_CE of 0.4 to 1.

2. The composition as claimed in claim 1 wherein the average RHAIk is 0.8 to 0.95 and the average RH_CE is 0.8 to 0.95.

3. The composition as claimed in claim 1 wherein (A) is a vinyl-substituted polydiorganosiloxane.

4. The composition as claimed in claim 1 wherein there is additionally present an additive selected from the group consisting of fillers, pigments, low temperature cure inhibitors, additives for improving adhesion, cross-linkers, chain extenders, pharmaceutical agents, cosmetic agents, natural extracts, silicone fluids, silicone waxes, silicone polyethers, hydrophilic polymers, and rheology modifers.

5. A silicone gel produced by reacting the composition as claimed in Claim 1.

6. The silicone gel as claimed in Claim 5 wherein the silicone gel has a softness between 50 and 250 mm/10 when using a penetration test equipped with a conical 62.5 g probe having a 65mm diameter.

7. The silicone gel as claimed in Claim 5 in which the layer of silicone gel has a thickness in the range of about 0.1 mm to 5 mm.

8. The silicone gel as claimed in Claim 5 in which the silicone gel is formed as a layer on a release liner.

9. A silicone gel forming composition comprising: (A) 55 to 95 wt% of at least one alkenyl-substituted polydiorganosiloxane;

(B) 1 to 30 wt% of at least one organosiloxane containing silicon-bonded hydrogen atoms;

(C) 0.005% to 2 wt.% of a hydroxy functional siloxane resin; and

(D) at least one hydrosilylation catalyst wherein (A) and (B) are present in amounts to provide an average RHAIk 0.7 to 1.5 and an average RH_CE of 0.4 to I .

10. The composition as claimed in claim 9 wherein the average RHAIk is 0.8 to 0.95 and the average RH_CE is 0.8 to 0.95

11. The composition as claimed in claim 9 wherein (A) is a vinyl-substituted polydiorganosiloxane.

12. The composition as claimed in claim 9 wherein there is additionally present an additive selected from the group consisting of fillers, pigments, low temperature cure inhibitors, additives for improving adhesion, cross-linkers, chain extenders, pharmaceutical agents, cosmetic agents, natural extracts, silicone fluids, silicone waxes, silicone polyethers, hydrophilic polymers, and rheology modifers.

13. A silicone gel produced by reacting the composition as claimed in Claim 9.

14. The silicone gel as claimed in Claim 9 wherein the silicone gel has a softness between 50 and 250 mm/10 when using a penetration test equipped with a conical 62.5 g probe having a 65mm diameter.

15. The silicone gel as claimed in Claim 9 in which the layer of silicone gel has a thickness in the range of about 0.1 mm to 5 mm.

16. The silicone gel as claimed in Claim 9 in which the silicone gel is formed as a layer on a release liner.

17. A method for adhering a medical substrate to a biological substrate comprising: (I) affixing to a medical substrate a layer of a silicone gel produced by reacting a composition comprising (A) 55 to 95 wt% of at least one alkenyl-substituted polydiorganosiloxane; (B) 1 to 30 wt% of at least one organosiloxane containing silicon-bonded hydrogen atoms and (D) at least one hydrosilylation catalyst; where in (A) and (B) are in such amounts to provide an average RHAIk of 0.7 to 1.5 and an average RH_CE of 0.4 to 1; (II) thereafter affixing the medical substrate containing the gel to the biological substrate.

18. The method according to claim 17 in which the average RHAIk is 0.8 to 0.95 and the average RH_CE is 0.8 to 0.95.

19. The method according to Claim 17 in which the medical substrate is made of a plastic selected from the group consisting of polyolefins, polyvinyls, polyurethanes and polyurethane-ureas, polyvinyl chloride derivatives, polyacrylic and polyacrylates derivatives, polyacrylonitrile, polyesters, cellulosic films, polyimides, polyamides, epoxy and phenolic plastics, polycarbonates, phenoplastes, epoxy resins, fluorinated polymers, polyoxymethylenes, polyphenylene oxides, polysulfones, polyphenyl sulfide, silicones and polysaccharide based materials.

20. The method according to Claim 19 in which the medical substrate is made of polyurethane.

21. The method as claimed in Claim 17 in which the silicone gel layer has a thickness in the range of about 0.1 mm to 5 mm.

22. The method as claimed in Claim 17 wherein the biological substrate is human.

23. The method as claimed in Claim 17 wherein the biological substrate is animal.

24. A method for adhering a medical substrate to a biological substrate comprising:

(I) affixing to a medical substrate a layer of a silicone gel produced by reacting a composition comprising (A) 55 to 95 wt% of at least one alkenyl-substituted polydiorganosiloxane; (B) 1 to 30 wt% of at least one organosiloxane containing silicon-bonded hydrogen atoms (C) 0.005% to 2 wt.% of a hydroxy functional siloxane resin; and (D) at least one hydrosilylation catalyst; where in (A) and (B) are in such amounts to provide an average RHAIk of 0.7 to 1.5 and an average RHc_E of 0.4 to 1;

(II) thereafter affixing the medical substrate containing the gel to the biological substrate.

25. The method according to claim 24 in which the average RHAIk is 0.8 to 0.95 and the average RH_CE is 0.8 to 0.95.

26 The method according to Claim 24 in which the medical substrate is made of a plastic selected from the group consisting of polyolefins, polyvinyls, polyurethanes and polyurethane-ureas, polyvinyl chloride derivatives, polyacrylic and polyacrylates derivatives, polyacrylonitrile, polyesters, cellulosic films, polyimides, polyamides, epoxy and phenolic plastics, polycarbonates, phenoplastes, epoxy resins, fluorinated polymers, polyoxymethylenes, polyphenylene oxides, polysulfones, polyphenyl sulfide, silicones and polysaccharide based materials.

27. The method according to Claim 26 in which the medical substrate is made of polyurethane.

28. The method as claimed in Claim 24 in which the silicone gel layer has a thickness in the range of about 0.1 mm to 5 mm.

29. The method as claimed in Claim 24 wherein the biological substrate is human.

30. The method as claimed in Claim 24 wherein the biological substrate is animal.