Skin-adhesive silicone gel

Abstract

The present invention relates to skin-adhesive silicone gels that can be used, in particular, for skin-adhesive articles for medical or paramedical use. The skin-adhesive article comprises, in particular, a layer of a skin-adhesive silicone gel obtained by crosslinking a silicone composition comprising at least one organopolysiloxane A, at least one branched organohydrogenpolysiloxane B and a catalytically effective amount of at least one polyaddition catalyst C.

Description

[0001] DESCRIPTION

[0002] TITLE: Skin-adhesive silicone gel

[0003] Technical field

[0004] The present invention relates to skin-adhesive silicone gels, useful in particular in skin-adhesive articles for medical or paramedical use. More particularly, the present invention relates to:

[0005] - a skin adhesive dressing, or part of such a dressing, in particular intended for the atraumatic removal of healthy skin and a wound, or

[0006] - a device for holding medical accessories, or part of such a device, used in contact with the skin, such as a sensor, probe, catheter or needle, or

[0007] - a transdermal drug delivery system, a patch.

[0008] State of the prior art

[0009] The use of silicone gels in medical devices intended to come into contact with the skin is now widespread. Indeed, the intrinsic properties of silicone gels mean that they adhere quickly to dry skin, but do not stick to the surface of a moist wound, thus not causing damage upon removal.

[0010] The prior art describes different types of medical devices comprising silicone gels.

[0011] The applicant company has, in the past, described in patent EP 3352804 B1 a skin-adhesive article comprising a support on which is coated an adhesive silicone gel having improved static shear strength, as well as good adhesion properties. Patent EP 3430086 B1 describes a silicone gel having good adhesion to a plastic support (for example polyurethane) and good tack to the skin.

[0012] US Patent 10,662,330 B2 also describes adhesive silicone gels useful for the manufacture of adhesive dressings having improved adhesion properties.

[0013] Patent KR 102549100 B1 describes a silicone adhesive composition, as well as dressings for medical use. The medical adhesive composition comprises: 40 to 78% by weight of vinyl-terminated polydimethylsiloxane, 20 to 58% by weight of polydimethylsiloxane having only one vinyl terminal, 0.5 to 5.0% by weight of a hydrogenosilyl-terminated poly(dimethylmethylhydrogen)siloxane crosslinking agent, 0.2 to 2.0% by weight of a hydrogenosilyl-terminated linear polydimethylsiloxane chain extender, 0.5 to 2.0% by weight of 1-ethylcyclohexanol as a retarder, and 0.1 to 1.5 parts by weight (per 100 parts by weight of silicone base) of a platinum-based catalyst. The crosslinking agent is a linear organohydrogenpolysiloxane whose SiH functions are found in the chain.Improved shear strength is a desirable property because it allows for effective and prolonged use in medical devices subjected to shear stresses, for example, from repeated rubbing of clothing on a dressing applied to a patient's skin, or when used as adhesives in ostomy bag fixation devices.

[0014] However, improving shear strength should not come at the expense of other important properties such as adhesive power (or peel strength).

[0015] An objective of the present invention is to provide a skin-adhesive article comprising a backing coated with an adhesive silicone gel having improved dynamic shear strength and adhesive power, preferably without residue.

[0016] Furthermore, silicone gels have been described in the literature for applications in the field of electronics. Indeed, silicone gels are commonly used for the encapsulation and protection of integrated circuits and other similar electronic components. Some documents describe silicone gels that may be structurally close to adhesive silicone gels for medical or paramedical use (for example, patents EP 2 395 053 Bl, EP 2 039 722 B1 and EP 0 851 000 A2). However, the properties sought for electronic applications are different. Gels for electronic applications are very fluid to allow good deposition of the product during encapsulation. Silicones are developed to have better tear resistance or excellent retention in the face of thermal variations (heat resistance 150°C, cold resistance -60°C).Finally, EP 0 851 000 A2 describes silicone compositions having improved adhesion to various substrates such as glass, textiles, paper, polyurethane, plastics such as polyester or polyvinyl chloride, and metals. These properties are of no use in the field of adhesives for medical or paramedical use.

[0017] Summary of the invention

[0018] The present invention therefore relates to a skin-adhesive article comprising:

[0019] - a support having a top face and a bottom face,

[0020] - optionally at least one bonding primer applied to at least part or all of the top face of said support,

[0021] - at least one layer of adhesive gel applied continuously or discontinuously to the top face of said support or to said bonding primer when present, and which consists of a silicone gel adhesive to the skin,

[0022] - optionally at least one protective layer consisting of a peelable protective material and applied to said adhesive gel layer, said silicone gel being obtained by crosslinking a silicone composition comprising:

[0023] - at least one organopolysiloxane A having, per molecule, at least one C2-C12 alkenyl group linked to silicon,

[0024] - at least one branched organohydrogenpolysiloxane B represented by the following general formula: lM' a M b D c From d T e Qf in which M: siloxyl unit R 2 3SiOi / 2, M': siloxyl unit R 2 2HSiOi / 2, D: siloxyl unit R 2 2SiO2 / 2, D': siloxyl unit R2 HSiO2 / 2, T: siloxyl unit R 2 SiOs / 2, Q: SiO4 / 2 siloxyl unit, with R 2 representing a monovalent radical having from 1 to 12 carbon atoms; a, b, c, d, e and f are numbers such that, for a+b+c+d+e+f = 100, 1 < a < 4, 0 < b < 2, 90 < c < 99, 0 < d < 0.1, 0.4 < (e+f) < 4, and

[0025] - a catalytically effective amount of at least one polyaddition catalyst C, the amounts by weight of the organopolysiloxanes A and B being determined so that the value of the RHalk ratio is within the following range: 0.5 < RHalk < 1.0, with RHalk = nH / tAlk, nH = number of moles of hydrogen atom directly bonded to a silicon atom of the organopolysiloxane B and tAlk = number of moles of alkenyl directly bonded to a silicon atom of the organopolysiloxane A.

[0026] Another object of the present invention relates to a method for preparing a skin adhesive article as described above. Said method comprises:

[0027] - a first step consisting of depositing on the top face of the support, or on the bonding primer when it is present, a sufficient quantity of the silicone composition precursor of adhesive gel according to the invention, and

[0028] - a second step consisting of crosslinking said silicone composition so as to form said layer of adhesive gel.

[0029] Finally, another subject of the present invention relates to an article adhesive to the skin characterized in that it is a medical or paramedical device, or an element of a medical or paramedical device.

[0030] Detailed description of the invention

[0031] Unless otherwise indicated, all viscosities of the silicone oils discussed in this disclosure correspond to a dynamic viscosity quantity at 25°C known as “Newtonian”, i.e. the dynamic viscosity which is measured, in a manner known per se, with a Brookfield viscometer at a shear rate gradient sufficiently low so that the measured viscosity is independent of the rate gradient.

[0032] In this text, the expression "silicone gel" refers to a crosslinked silicone product characterized in particular by a penetration rate (or "penetrability") of between 50 and 500 tenths of a mm. Penetrability is measured by penetrometry, typically according to standard NF ISO 2137, using a Petrotest PNR 12 penetrometer with a total weight of the rod and cone set at 62.5 g. The cone penetrability of a silicone gel is determined at 25°C by measuring the depth of penetration of the cone into the sample, this being obtained by releasing the cone assembly from the penetrometer and leaving the cone to act for 5 seconds.

[0033] The present invention therefore relates to a skin-adhesive article which comprises in particular a layer of a skin-adhesive silicone gel. Said silicone gel is obtained by crosslinking a silicone composition comprising at least one organopolysiloxane A, at least one branched organohydrogenpolysiloxane B and a catalytically effective amount of at least one polyaddition catalyst C.

[0034] In the following section regarding the description of organopolysiloxane A, the following nomenclature has been used to represent the siloxyl units:

[0035] M: siloxyl unit R SiO ,

[0036] M V1 : siloxyl unit chosen from YRkSiOi / and YzR'SiOi / z.

[0037] D: siloxyl unit R SiCL / z.

[0038] D V1 : siloxyl unit chosen from YzSiCL / z and YR'SiCL / z.

[0039] T: siloxyl unit R'SiCL / z.

[0040] Q: siloxyl unit SiC>4 / 2, with Y and R 1such that: Y represents a C2-C12 alkenyl group, preferably a vinyl group; R 1 represents a monovalent hydrocarbon group having from 1 to 12 carbon atoms, preferably selected from alkyl groups having from 1 to 8 carbon atoms such as methyl, ethyl, propyl groups, cycloalkyl groups having from 3 to 8 carbon atoms and aryl groups having from 6 to 12 carbon atoms.

[0041] As examples of terminal motifs M and M V1 , we can cite the trimethylsiloxy, dimethylphenylsiloxy, dimethylvinylsiloxy or dimethylhexenylsiloxy groups.

[0042] As examples of patterns D and D V1 , we can cite the dimethylsiloxy, methylphenylsiloxy, methylvinylsiloxy, methylbutenylsiloxy, methylhexenylsiloxy, methyldecenylsiloxy or methyldecadienylsiloxy groups.

[0043] Examples of T units include the methylsiloxy group.

[0044] It is understood in the above formulas that, if several R groups 1 are present, they can be the same or different from each other.

[0045] The organopolysiloxane A according to the invention has, per molecule, at least one C2-C12 alkenyl group linked to silicon, preferably at least two C2-C12 alkenyl groups linked to silicon.

[0046] Preferably, the organopolysiloxane compound A has a mass content of alkenyl units of between 0.001% and 30%, preferably between 0.01% and 10%, preferably between 0.02% and 5%, and even more preferably between 0.05% and 1% (mass % of alkenyl units, based on the total weight of the organopolysiloxane A). The silicone composition preferably comprises from 40% to 98% by weight of organopolysiloxane A, even more preferably from 50% to 95% by weight of organopolysiloxane A.

[0047] Preferably, said organopolysiloxanes A are oils with a dynamic viscosity of between 50 mPa.s and 100,000 mPa.s, preferably between 100 mPa.s and 80,000 mPa.s, and more preferably between 1,000 mPa.s and 60,000 mPa.s.

[0048] Preferably, the organopolysiloxane A may have a linear structure. By “linear structure” is meant a structure which does not contain, or substantially does not contain, siloxy units T and / or Q. It may consist essentially of siloxyl units selected from M, M V1 , D, D V1 , and combinations thereof. Preferably, it may be a linear organopolysiloxane formed from at least two siloxyl units M V1 and D patterns.

[0049] Examples of linear organopolysiloxanes which may be an organopolysiloxane A according to the invention are:

[0050] - a poly(dimethylsiloxane) with dimethylvinylsilyl ends;

[0051] - a poly(dimethylsiloxane-co-methylphenylsiloxane) with dimethylvinylsilyl ends;

[0052] - a poly(dimethylsiloxane-co-methylvinylsiloxane) with dimethylvinylsilyl ends; and

[0053] - a poly(dimethylsiloxane-co-methylvinylsiloxane) with trimethylsilyl ends; poly(dimethylsiloxane) with dimethylvinylsilyl ends being particularly preferred.

[0054] According to a first embodiment, the silicone composition precursor of the adhesive gel according to the invention comprises only one linear organopolysiloxane A, or a mixture of several linear organopolysiloxanes A. According to this first embodiment, said silicone composition does not comprise, or substantially does not comprise, organopolysiloxane(s) A having a branched structure. By “branched structure” is meant a structure which contains siloxy units T and / or Q.

[0055] According to a second embodiment, the silicone composition precursor of the adhesive gel according to the invention comprises a mixture of at least one linear organopolysiloxane A and at least one branched organopolysiloxane A.

[0056] Branched organopolysiloxanes A, sometimes referred to as silicone resins, are well-known and commercially available compounds. They are typically available in diluted form, preferably in a vinyl silicone oil or a mixture of silicone oil and silicone gum, or in a solvent, for example, xylene.

[0057] In a branched organopolysiloxane A, the alkenyl groups may be located on siloxyl units M, D or T. Examples of branched organopolysiloxanes that may be an organopolysiloxane A according to the invention are:

[0058] - MD V1 Q, where vinyl groups are included in the D units,

[0059] - MD V1T, where vinyl groups are included in the D units,

[0060] - MD V1 TQ, where vinyl groups are included in D motifs,

[0061] - MM V1 Q, where vinyl groups are included in part of the M, - MM units V1 T, where vinyl groups are included in part of the M units,

[0062] - MM V1 TQ, where vinyl groups are included in part of the M motifs,

[0063] - MM V1 DD V1 Q, where vinyl groups are included in the M and D units,

[0064] - MM V1 DD V1 T, where vinyl groups are included in the M and D units,

[0065] - MM V1 DD V1 TQ, where vinyl groups are included in the M and D units,

[0066] - and their mixtures; MM compounds V1 Q and MD V1 Q being particularly preferred.

[0067] In said second embodiment, the amount of organopolysiloxane A connected in the silicone composition precursor of the adhesive gel according to the invention is preferably between 0.1% and 5% by weight, more preferably between 1.0% and 3% by weight.

[0068] In the following section concerning the description of organohydrogenopolysiloxane B, the following nomenclature has been used to represent the siloxyl units:

[0069] M: siloxyl unit R 2 3SiOi / 2,

[0070] M': siloxyl motif R 2 2HSiOi / 2,

[0071] D: siloxyl unit R 2 2SiC>2 / 2,

[0072] D': siloxyl motif R 2 HSiC>2 / 2,

[0073] T: siloxyl unit R 2 SiC>3 / 2,

[0074] Q: siloxyl unit SiC>4 / 2, with R 2 representing a monovalent radical having from 1 to 12 carbon atoms.

[0075] It is understood that, if several R groups2 are present in the above formulas, they can be the same or different from each other. R 2 represents a group preferably selected from alkyl groups having from 1 to 8 carbon atoms such as methyl, ethyl, propyl groups, cycloalkyl groups having from 3 to 8 carbon atoms and aryl groups having from 6 to 12 carbon atoms. R 2 preferably does not include an alkenyl function, in particular no vinyl function.

[0076] The branched organohydrogenpolysiloxane B according to the present invention is represented by the following general formula:

[0077] M'a Mb De D' d Te Qf in which a, b, c, d, e and f are numbers such that, for a+b+c+d+e+f = 100, 1 < a < 4, 0 < b < 2, 90 < c < 99, 0 < d < 0.1, 0.4 < (e+f) < 4.

[0078] It may be noted that this general formula is an apparent average formula and does not reflect the actual structure of the molecule or its molecular weight. The apparent formula is obtained by NMR analysis, analysis of the relative ratios of the different siloxyl units present, and representation of these ratios by a model of an equivalent molecule. The actual molecules can thus be much larger or much smaller than the apparent formula indicated. The presence of D' units in the branched organohydrogenpolysiloxane B according to the invention is optional. According to one embodiment, the branched organohydrogenpolysiloxane B does not contain, or substantially does not contain, D' units. Thus, d < 0.1, more preferably d < 0.05, and even more preferably d = 0. The hydrogen atoms of the SiH units are therefore carried mainly, or even exclusively, at the end of the chain by M' units.

[0079] The ratio (a+b) / (c+d) is preferably between 0.01 and 0.05, more preferably between 0.012 and 0.04.

[0080] The ratio (a+b) / (e+f) is preferably between 0.5 and 10, more preferably between 1 and 7.

[0081] The ratio (a) / (e+f) is preferably between 0.5 and 7, more preferably between 1 and 5.

[0082] Preferably, the branched organohydrogenpolysiloxane B has a mass content of SiH units of between 0.5% and 10%, more preferably between 0.7% and 5%, even more preferably between 0.8% and 2% (mass % of SiH units, based on the total weight of the organohydrogenpolysiloxane B).

[0083] Optionally, although not shown in the general formula, the branched organohydrogenpolysiloxane B may contain hydroxy OH groups. Said hydroxy groups may be carried by a D unit, a T unit, a Q unit, or a mixture thereof, then having respectively the formula R 2 2(OH)SiOi / 2 (= D OH ), R 2 (OH)SiO2 / 2 (= T OH ) and (OH)SiO3 / 2 (=Q OH ). Preferably, the branched organohydrogenpolysiloxane B has a mass content of OH units of between 0% and 1% (mass % of OH units, based on the total weight of the organohydrogenpolysiloxane B).

[0084] According to a first embodiment, the branched organohydrogenpolysiloxane B comprises T units but not, or substantially not, Q units. It can be represented by the general formula above in which f < 0.1, more preferably f < 0.05, and even more preferably f = 0.

[0085] According to a second embodiment, the branched organohydrogenpolysiloxane B comprises Q units but not, or substantially not, T units. It can be represented by the general formula above in which e < 0.1, more preferably e < 0.05, and even more preferably e = 0.

[0086] The silicone precursor composition of the adhesive gel according to the invention preferably comprises 1% to 20% by weight, and more preferably from 3% to 15% by weight, of the branched organohydrogenpolysiloxane B.

[0087] According to one embodiment, the silicone composition according to the invention may further comprise at least one linear organohydrogenpolysiloxane. A linear organohydrogenpolysiloxane is essentially composed of siloxyl units D and / or D', and of terminal siloxyl units M and / or M'. Examples of linear organohydrogenpolysiloxanes are:

[0088] - a poly(dimethylsiloxane) with hydrogenodimethylsilyl ends,

[0089] - a poly(dimethylsiloxane-co-methylhydrogensiloxane) with trimethylsilyl ends, - a poly(dimethylsiloxane-co-methylhydrogensiloxane) with hydrogenodimethylsilyl ends, and

[0090] - a poly(methylhydrogensiloxane) with trimethylsilyl ends.

[0091] Poly(dimethylsiloxane) compounds with hydrogenodimethylsilyl ends, of general formula M'D XM' (x being typically between 0 and 100, and preferably between 1 and 50, and even more preferably between 3 and 30), are called "chain extenders". Particularly advantageous organohydrogenpolysiloxane chain extenders are polydimethylsiloxane oils with dimethylhydrogenosilyl ends having a dynamic viscosity at 25°C between 1 mPa.s and 500 mPa.s, preferably between 1 mPa.s and 250 mPa.s, and even more preferably between 1 mPa.s and 50 mPa.s.

[0092] When present, the amount of linear organohydrogenpolysiloxanes in the silicone precursor composition of the adhesive gel according to the invention is preferably between 0.1% and 5% by weight, more preferably between 1.5% and 3% by weight.

[0093] According to one embodiment, the silicone composition according to the invention does not contain, or substantially does not contain, silicone resins of formulas M'Q or MM'Q. Their concentration in the silicone composition precursor of the adhesive gel according to the invention is preferably less than 1% by weight, more preferably less than 0.1%, even more preferably between 0% and 0.01% by weight.

[0094] The amounts by weight of organopolysiloxanes A and B are determined so that the value of the RHalk ratio is within the following range: 0.5 < RHalk < 1.0, with RHalk = nH / tAlk, nH = number of moles of hydrogen atom directly bonded to a silicon atom of organopolysiloxane B and tAlk = number of moles of alkenyl directly bonded to a silicon atom of organopolysiloxane A.

[0095] The polyaddition catalyst C may in particular be chosen from platinum and rhodium compounds but also from silicon compounds such as those described in patent applications WO 2015 / 004396 and WO 2015 / 004397, germanium compounds such as those described in patent applications WO 20160 / 75414, nickel, cobalt or iron complexes such as those described in patent applications WO 2016 / 071651, WO 2016 / 071652, WO 2016 / 071654,

[0096] WO 2018 / 115601, WO 2019 / 008279, WO 2019 / 138194, WO 2023 / 031524 and WO 2023 / 031525, or manganese complexes such as those described in applications WO 2023 / 139322 and WO 2024 / 146993. Catalyst C is preferably a compound derived from at least one metal belonging to the platinum group. These catalysts are well known. In particular, it is possible to use the complexes of platinum and an organic product described in US patents 3,159,601, US 3,159,602, US 3,220,972 and European patents EP 0.057.459, EP 0.188.978 and EP 0.190.530, the complexes of platinum and vinyl organosiloxanes described in US patents 3,419,593, US 3,715,334, US 3,377,432 and US 3,814,730.

[0097] Alternatively, a polyaddition photocatalyst may be used. Such a catalyst may be activated by irradiation, preferably by UV irradiation. A platinum-based photocatalyst may be selected, for example, from: platinum bis(acetylacetonate), platinum trimethyl(acetylacetonate), platinum trimethyl(2,4-pentanedione), platinum trimethyl(3,5-heptanedione), platinum trimethyl(methyl acetoacetate), platinum bis(2,4-pentanedione), platinum bis(2,4-hexanedione), platinum bis(2,4-heptanedione), platinum bis(3,5-heptanedione) and platinum bis(1-phenyl-1,3-butanedione).

[0098] Preferably, catalyst C is a compound derived from platinum. In this case, the weight quantity of catalyst C, calculated as the weight of platinum metal, is generally between 2 ppm and 400 ppm by mass, preferably between 5 ppm and 200 ppm, based on the total weight of the silicone composition.

[0099] Preferably, catalyst C is a Karstedt platinum.

[0100] Furthermore, the silicone composition precursor of the adhesive silicone gel according to the invention may also comprise other compounds, in particular additives known to those skilled in the art and useful for the intended application.

[0101] According to one embodiment, the silicone precursor composition of the adhesive silicone gel according to the invention may optionally comprise a crosslinking inhibitor. The function of the inhibitor is to slow down the polyaddition reaction. The crosslinking inhibitor may be chosen from the following compounds:

[0102] - an organopolysiloxane, advantageously cyclic, and substituted by at least one alkenyl, tetramethylvinyltetrasiloxane being particularly preferred,

[0103] - pyridine,

[0104] - organic phosphines and phosphites,

[0105] - unsaturated amides,

[0106] - alkylated maleates, and

[0107] - acetylenic alcohols.

[0108] Preferably, the crosslinking inhibitor is an acetylenic alcohol of formula (R 3 )(R 4 )C(OH)- C=CH, in which:

[0109] - R 3 is a linear or branched alkyl radical, or a phenyl radical,

[0110] - R 4 is a hydrogen atom, a linear or branched alkyl radical, or a phenyl radical,

[0111] - the R radicals 3 , R 4 and the carbon atom located alpha to the triple bond which can possibly form a cycle, and - the total number of carbon atoms contained in R 3 and R 4 being at least 5, preferably 9 to 20.

[0112] Said alcohols are preferably chosen from those having a boiling point above 250°C. Examples which may be mentioned are the following products which are commercially available: 1-ethynyl-1-cyclohexanol, methyl-3-dodecyne-1-ol-3, trimethyl-3,7,1-dodecyne-1-ol-3, diphenyl-1,1-propyne-2-ol-1, ethyl-3-ethyl-6-nonyne-1-ol-3 and methyl-3-pentadecyne-1-ol-3. Preferably, the crosslinking inhibitor is 1-ethynyl-1-cyclohexanol.

[0113] The presence of the inhibitor may or may not be necessary depending on the silicone composition and the process used. If necessary, such a crosslinking inhibitor may typically be present at a maximum of 3000 ppm, preferably at a maximum of 100 ppm to 2000 ppm relative to the total weight of the silicone composition.

[0114] The silicone composition may optionally comprise at least one diorganopolysiloxane gum. Diorganopolysiloxane gums are linear polymers of high molecular weight with a viscosity greater than 1000 Pa.s at 25°C, preferably greater than 2000 Pa.s and whose diorganopolysiloxane chain is essentially made up of units of formula R2SiO 2 / 2and blocked at each end by units of formula R2S i O i / 2, the radical R represents an alkyl radical having from 1 to 8 carbon atoms or an alkenyl radical having from 2 to 6 carbon atoms. The presence, along the diorganopolysiloxane chain, of small quantities of units other than R2SiO2 / 2, for example RSiC>3 / 2 and / or SiC>4 / 2 units, is however not excluded in the proportion of at most 2% relative to the number of R2SiO2 / 2 units. Preferably, the diorganopolysiloxane gums comprise at least two C2-Ci2 alkenyl groups linked to silicon. Advantageously, the diorganopolysiloxane gum has a mass content of vinyl units greater than 0.3%, preferably greater than 0.5%, more preferably between 0.5% and 6%, even more preferably between 0.5% and 4%, and even more preferably between 1% and 3.5%.

[0115] According to one embodiment, the silicone composition precursor of the adhesive silicone gel according to the present invention may contain a low level of volatile organic compounds, typically less than 100 pgC / g, preferably less than 70 pgC / g, or even less than 50 pgC / g. For this, the organopolysiloxane compounds used in the composition according to the present invention may preferably be chosen from compounds themselves containing a low level of volatile organic compounds.

[0116] According to one embodiment, the silicone composition precursor of the adhesive silicone gel comprises (by weight relative to the total weight of the silicone composition):

[0117] - from 40% to 98% by weight of at least one organopolysiloxane A as defined above,

[0118] - from 1% to 20% of at least one branched organohydrogenpolysiloxane B as defined above, - from 2 ppm to 400 ppm by mass of a polyaddition catalyst C chosen from platinum compounds (quantity calculated by weight of platinum metal),

[0119] - from 0 to 3000 ppm by weight of a crosslinking inhibitor.

[0120] According to another embodiment, the silicone composition precursor of the adhesive silicone gel comprises (by weight relative to the total weight of the silicone composition):

[0121] - from 50% to 95% by weight of at least one linear organopolysiloxane A as defined above,

[0122] - from 0% to 5% by weight of at least one branched organopolysiloxane A as defined above,

[0123] - from 3% to 15% of at least one branched organohydrogenpolysiloxane B as defined above,

[0124] - from 0% to 5% of at least one linear organohydrogenpolysiloxane as defined above,

[0125] - from 2 ppm to 400 ppm by mass of a polyaddition catalyst C chosen from platinum compounds (quantity calculated by weight of platinum metal),

[0126] - from 0 to 3000 ppm by weight of a crosslinking inhibitor.

[0127] The silicone composition precursor of the adhesive gel according to the invention can be prepared from a two-component (or multi-component) system characterized in that it is presented in two (or more) distinct parts intended to be mixed to form said silicone composition. In particular, in the case of the preferred silicone compositions as described above, the silicone composition can be prepared from a two-component system characterized in that one of the parts comprises catalyst C and does not comprise organohydrogenpolysiloxane B, while the other part comprises organohydrogenpolysiloxane B and does not comprise catalyst C. Other multi-component systems can be provided to improve the storage life and / or optimize the viscosity of each of the components.

[0128] After mixing in the case of a two-component or multi-component system, the silicone composition precursor of the adhesive gel can be used for the manufacture of the skin-adhesive article according to the present invention. For this, the silicone composition is deposited to form a layer of adhesive gel. The viscosity of the silicone composition is preferably between 5000 mPa.s and 100000 mPa.s, more preferably between 10000 mPa.s and 50000 mPa.s.

[0129] The skin-adhesive article according to the invention comprises a support having a top face and a bottom face. According to a preferred embodiment, the support is a woven, non-woven or knitted textile, or a plastic film.

[0130] A wide variety of plastics may be suitable for use as a backing according to the invention. Examples include polyvinyl chloride, polypropylene, regenerated cellulose, polyethylene terephthalate (PET) and polyurethane, particularly meltblown polyurethane. Preferably, the backing is a continuous or perforated flexible polyurethane film. This flexible polyurethane film may be made from meltblown polyurethane. Preferably, a transparent or translucent flexible polyurethane film is used. When the adhesive article is used as a dressing, the use of a transparent or translucent film has the advantage of allowing observation of the wound, injury or catheter entry site over which the dressing is to be centered.

[0131] Preferably, said support is a flexible polyurethane film having a thickness of 5 μm to 600 μm, preferably of 5 μm to 250 μm and even more preferably of 10 μm to 100 μm.

[0132] According to a preferred embodiment, the support is a continuous flexible film which is permeable to air and impermeable to fluids. The film may have a variable moisture vapor transmission rate (MVTR) depending on the intended application. A technique for measuring the moisture vapor transmission rate in liquid contact is described in standard NF-EN 13726-2. Preferably, the flexible film will be chosen so as to obtain a dressing having a moisture vapor transmission rate greater than 300 g / m 2 / 24 hours, preferably greater than or equal to 600 g / m 2 / 24 hours, preferably greater than or equal to 1000 g / m 2 / 24 hours.

[0133] According to one embodiment of the invention, the support is a perforated flexible film, so as to be able to promote the circulation of exudates. In this particular embodiment, it is advantageous for the perforations of the support to be circular and have a diameter of 50 μm to 10 mm.

[0134] In a particular embodiment, the invention relates to a skin-adhesive article characterized in that the backing is a flexible polyurethane film and comprises on at least a portion of the underside a pressure-sensitive adhesive ("PSA"). The pressure-sensitive adhesive can be any of the numerous pressure-sensitive adhesives known in the art. Examples of pressure-sensitive adhesives include rubber / resin adhesives, which are mixtures of rubbery material and hard resin, and acrylic (or acrylate) adhesives. Preferably for use in the present invention, the pressure-sensitive adhesive is an acrylic adhesive.

[0135] Optionally, at least one bonding primer may be applied to at least part or all of the top face of said support.

[0136] Examples of bonding primers include:

[0137] - Primers formulated in a solvent medium. An example is described in the patent application

[0138] WO 2011 / 092404 from the company Bluestar Silicones France, where a primer is made up of an active material (organopolysiloxane oil with hydrogenosilyl (SiH) and Si-alkenyl function or a silicone resin with hydrogenosilyl function) diluted in a silicone solvent (cyclopentasiloxane).

[0139] - The primers described in patent application WO 2016 / 207498 in the name of the company Bluestar Silicones.

[0140] - Silicone elastomer primers which are prepared from precursor compositions crosslinking by a polyaddition reaction, and comprising adhesion promoters which improve adhesion to various substrates, typically silanes. In addition, the skin-adhesive article may optionally comprise at least one protective layer made of a peelable protective material.

[0141] The protective layer made of a peelable protective material may consist of one or more parts that can be peeled off before use. This protective layer preferably covers the entire surface of the gel of the adhesive article and may be made of any material commonly used as protection by those skilled in the art in the field of dressings. It may be in the form of a film, for example a polyolefin film such as polyethylene or polypropylene or a polyester film. This film may advantageously be treated on at least one of its faces with a silicone compound such as a silane, a fluorinated compound, or a silicone and fluorinated compound. The choice of material is generally adapted to the nature of the silicone gel. The thickness of the protective layer made of a peelable protective material is preferably between 10 μm and 100 μm.

[0142] In addition to the elements described above, the skin-adhesive article according to the invention may comprise one or more additional element(s), for example intermediate layers, known to those skilled in the art and useful for the intended application. Mention may typically be made of the addition of an absorbent body, for example a hydrophilic foam, a fabric pad, a hydrogel, a hydrocolloid, an alginate, etc.

[0143] Another object of the present invention relates to a method for preparing a skin adhesive article as described above. Said method comprises:

[0144] - a first step consisting of depositing on the top face of the support, or on the bonding primer when it is present, a sufficient quantity of the silicone composition precursor of adhesive gel according to the invention, and

[0145] - a second step consisting of crosslinking said silicone composition so as to form said layer of adhesive gel.

[0146] Said method may further comprise:

[0147] - an optional preliminary step consisting of preparing and depositing said bonding primer on the face of the support; and / or

[0148] - an optional subsequent step consisting of depositing the protective layer on the adhesive gel layer.

[0149] The deposition on the top face of the support, or on the bonding primer when present, of the silicone composition precursor of adhesive gel may be total or partial, that is to say that the deposition of the silicone composition may be carried out on the entire surface or on one or more parts of this surface.

[0150] Preferably, the quantity of silicone composition deposited is determined so as to obtain a layer of adhesive gel of between 50 g / cm 2 and 300 g / cm 2 of support, preferably between 100 g / cm 2 and 200 g / cm 2 The thickness of the adhesive gel layer may be between 50 pm and 300 pm, preferably between 100 pm and 200 pm.

[0151] As a technique for depositing the silicone composition, we can cite for example the coating techniques carried out by doctor blade, in particular by doctor blade on cylinder, doctor blade in the air and doctor blade on belt, or by padding, that is to say by squeezing between two rollers, or by licking roller, rotating frame, reverse roll or transfer, by spraying, or by curtain coating.

[0152] The second stage of crosslinking of the silicone composition can have a variable duration depending in particular on the silicone composition and the temperature of the crosslinking stage. Generally, a gel with good properties is obtained after a few minutes depending on the temperature and the concentration of catalyst and inhibitor in the silicone composition. The silicone composition can crosslink without external intervention if the reactivity between the parts brought into contact beforehand is sufficient. It is possible to thermally activate the crosslinking reaction. The means of thermal activation of the crosslinking are conventionally ovens (for example tunnel ovens), heated laminating rollers, or infrared sources. This thermal activation can be supplemented by actinic activation and / or by electron bombardment.The crosslinking temperature may be higher than 120°C, without exceeding the degradation temperature of the support, preferably between 160°C and 200°C.

[0153] After crosslinking, the silicone gel advantageously has a penetrability of between 50 and 500 tenths of a mm, more preferably between 100 and 200 tenths of a mm.

[0154] Another subject of the present invention relates to an article adhesive to the skin characterized in that it is a medical or paramedical device, or an element of a medical or paramedical device.

[0155] More particularly, said skin-adhesive article may be:

[0156] - a skin adhesive dressing, or part of such a dressing, in particular intended for the atraumatic removal of healthy skin and a wound, or

[0157] - a device for holding medical accessories, or part of such a device, used in contact with the skin, such as a sensor, probe, catheter or needle, or

[0158] - a transdermal drug delivery system, a patch.

[0159] Other details or advantages of the invention will appear more clearly from the examples given below for information purposes only.

[0160] Examples

[0161] The silicone compositions described as examples below were obtained from the following raw materials: Al: Polydimethylsiloxane oil, chain end, average viscosity 35,000 mPa.s

[0162] A2: MD type vinyl silicone resin V1 Q, vinyl group content = 2.4% by weight

[0163] Bl, B2, B3, B4, B5, B6: Branched organohydrogenpolysiloxane compounds defined in Table 1 below: [Table 1]

[0164] (general formula obtained by NMR analysis of proton and silicon on a Bruker device at 400 Hz)

[0165] B7: Hydrogendimethylpolysiloxane oil with SiH groups at the end of the chain (a / co), having a SiH content of 5.7% by weight, viscosity = 8.5 mPa.s

[0166] B 8: Poly(methylhydrogen)(dimethyl)siloxane oil with SiH groups in the middle and end of the chain (a / co), having a SiH content of 7.3% by weight, viscosity = 30 mPa.s

[0167] C: Karstedt platinum catalyst, containing 10% by weight of platinum metal

[0168] ECH: 1-ethynyl-l-cyclohexanol

[0169] Examples 1-3 and comparative examples C1 and C2: Silicone compositions were prepared by mixing the different compounds according to the concentration indicated in Table 2 below.

[0170] [Table 2]

[0171] (% by weight)

[0172] After mixing, the silicone composition was deposited onto a substrate sheet and coated using a coating blade, previously adjusted to ensure a coating thickness of 150 μm.

[0173] The substrate used was a 100 μm thick polyurethane (PU) from the Covestro brand. One side of the PU was previously primed with a silicone composition as described in patent application WO 2011 / 092404 from Bluestar Silicones France.

[0174] The coating was then cured flat in an oven at 120°C for 30 minutes. Finally, it was covered with a protective liner film 30 minutes after removal from the oven.

[0175] The analyses were carried out according to the measurement protocols described below:

[0176] Crosslinking: The crosslinking of a coating was assessed by touching the coating with a finger. “Yes” means that crosslinking and adhesion are satisfactory. “No” means incomplete crosslinking, the product leaves a lot of residue on the finger.

[0177] Penetration: Penetration measurement is carried out using the PNR12 penetrometer, equipped with a 47.5g drop rod with a 10mm diameter and a 15g hollow plexiglass cone with a stainless steel tip. The drop time of the cone in the gel is 5 seconds. The result is the average of three measurements taken on the same sample, and is expressed in 1 / 10 mm.

[0178] Shear: The dynamic shear strength of a silicone gel quantifies the resistance of the gel on a standardized surface, representing the skin, when the gel is subjected to a constant shear force. The dynamic shear strength was evaluated using the methodology described in FINAT Test Method No. 18 (FINAT Technical Handbook 6 th edition, 2001). More specifically, test pieces (5 cm x 2.5 cm) were cut from the previously made coating. A 2 cm x 2.5 cm area of ​​this test piece was glued onto Bristol board measuring 4 cm x 5 cm, then the whole thing was mounted with a 2 kg weight. The shear force was measured on the INSTRON extensometer by traction at 5 mm / minute.

[0179] Peel: The peel force of a silicone gel from the skin is the force required to detach the gel from a sheet of Bristol paper, simulating the skin, of well-defined dimensions, at an angle of 180° and at a constant speed of 300 mm / min and with the help of a 10 N (newtons) force cell in the case of silicone gels. It is evaluated by the methodology described in FINAT Test Method No. 1 (FINAT Technical Handbook 6 th edition, 2001). More specifically, test pieces (2.5 cm x 14 cm) were cut from the previously made coating. The adhesive gel was stuck onto the Bristol paper and mounted with a 2 kg weight. The peel test was carried out using the Cheminstrument “180° Peel Adhesion” peel bench at a speed of 30 cm / min.

[0180] The results are presented in Table 3 below.

[0181] [Table 3] * not measured

Claims

CLAIMS 1. Skin adhesive article comprising: - a support having a top face and a bottom face, - optionally at least one bonding primer applied to at least part or all of the top face of said support, - at least one layer of adhesive gel applied continuously or discontinuously to the top face of said support, or to said bonding primer when present, and which consists of a silicone gel adhesive to the skin, - optionally at least one protective layer consisting of a peelable protective material and applied to said adhesive gel layer, said silicone gel being obtained by crosslinking a silicone composition comprising: - at least one organopolysiloxane A having, per molecule, at least one C2-C12 alkenyl group linked to silicon, - at least one branched organohydrogenpolysiloxane B represented by the following general formula: M'a Mb De D' d Te Qf in which M: siloxyl unit R 2 3SiOi / 2, M': siloxyl unit R 2 2HSiOi / 2, D: siloxyl unit R 2 2SiC>2 / 2, D': siloxyl unit R 2 HSiC>2 / 2, T: siloxyl unit R 2 SiOs / 2, Q: siloxyl unit SiC>4 / 2, with R 2 representing a monovalent radical having from 1 to 12 carbon atoms; a, b, c, d, e and f are numbers such that, for a+b+c+d+e+f = 100, l < a < 4, 0 < b < 2, 90 < c < 99, 0 < d < 0.1, 0.4 < (e+f) < 4, and - a catalytically effective amount of at least one polyaddition catalyst C, the amounts by weight of the organopolysiloxanes A and B being determined so that the value of the RHalk ratio is within the following range: 0.5 < RHalk < 1.0, with RHalk = nH / tAlk, nH = number of moles of hydrogen atom directly bonded to a silicon atom of T organopolysiloxane B and tAlk = number of moles of alkenyl directly bonded to a silicon atom of T organopolysiloxane A.

2. Skin adhesive article according to claim 1, in which the branched organohydrogenpolysiloxane B has a mass content of SiH unit of between 0.5% and 10%, more preferably between 0.7% and 5%, even more preferably between 0.8% and 2%, based on the total weight of T organohydrogenopolysiloxane B.

3. Skin adhesive article according to claim 1 or claim 2, wherein in the general formula of T branched organohydrogenpolysiloxane B, f < 0.1, more preferably f < 0.05, and even more preferably f = 0.

4. Skin adhesive article according to claim 1 or claim 2, wherein in the general formula of T branched organohydrogenpolysiloxane B, e < 0.1, more preferably e < 0.05, and even more preferably e = 0.

5. A skin adhesive article according to any one of claims 1 to 4, wherein the silicone composition further comprises at least one linear organohydrogenpolysiloxane.

6. Skin adhesive article according to any one of claims 1 to 5, in which the silicone composition comprises only one linear organopolysiloxane A, or a mixture of several linear organopolysiloxanes A.

7. Skin adhesive article according to any one of claims 1 to 5, in which the silicone composition comprises a mixture of at least one linear organopolysiloxane A and at least one branched organopolysiloxane A.

8. Skin adhesive article according to claim 7, in which the amount of organopolysiloxane A branched in the silicone composition precursor of the adhesive gel is between 0.1% and 5% by weight.

9. Skin adhesive article according to any one of claims 1 to 8, in which the silicone composition precursor of the adhesive silicone gel comprises, by weight relative to the total weight of the silicone composition: - from 40% to 98% by weight of said at least one organopolysiloxane A, - from 1% to 20% by weight of said at least one branched organohydrogenpolysiloxane B, - from 2 ppm to 400 ppm by mass of said polyaddition catalyst C chosen from platinum compounds (quantity calculated by weight of platinum metal), - from 0 to 3000 ppm by weight of a crosslinking inhibitor.

10. Skin adhesive article according to any one of claims 1 to 9, in which the silicone composition precursor of the adhesive silicone gel comprises, by weight relative to the total weight of the silicone composition: - from 50% to 95% by weight of said at least one linear organopolysiloxane A, - from 0% to 5% by weight of said at least one branched organopolysiloxane A, - from 3% to 15% by weight of said at least one branched organohydrogenpolysiloxane B, - from 0% to 5% by weight of at least one linear organohydrogenpolysiloxane, - from 2 ppm to 400 ppm by mass of said polyaddition catalyst C chosen from platinum compounds (quantity calculated by weight of platinum metal), - from 0 to 3000 ppm by weight of a crosslinking inhibitor.

11. A method of preparing a skin-adhesive article according to any one of claims 1 to 10, said method comprising: - a first step consisting of depositing on the top face of the support, or on the bonding primer when it is present, a sufficient quantity of the silicone composition precursor of adhesive gel as defined in any one of claims 1 to 10, and - a second step consisting of crosslinking said silicone composition so as to form said layer of adhesive gel.

12. Skin adhesive article according to any one of claims 1 to 10, characterized in that it is a medical or paramedical device, or an element of a medical or paramedical device.

13. Skin adhesive article according to claim 12, characterized in that it is: - an adhesive skin dressing, or part of such a dressing, in particular intended for the atraumatic removal of healthy skin and a wound, or - a device for holding medical accessories, or part of such a device, used in contact with the skin, such as a sensor, probe, catheter or needle, or - a transdermal drug delivery system, a patch.

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