Self-adhesive multi-layer item and method for the production thereof

A process for preparing a self-adhesive multi-layer item comprising a dorsal support DO having a top face SI1 and a bottom face SI2 and a first layer of silicone release coating RC, the process comprising a) to d):

• a) applying between 0.1 and 5 g per m2 of the composition C on the top face SI1 of the dorsal support DO to obtain the dorsal support DO coated with composition C, wherein composition C is a curable silicone composition not containing any solvent comprising 1 and 2:
• 1) at least one functionalized organopolysiloxane A comprising:
• i) at least one unit of formula (I):
• RaZbSiO(4-a-b)/2 (I)
• wherein
• R, which may be identical or different, each represent a linear or branched C1 to C18 alkyl group, a C6 to C12 aryl or aralkyl group, which is optionally substituted, optionally with halogen atoms, or an alkoxy radical —OR4 with R4 being a hydrogen atom or a hydrocarbon-based radical comprising from 1 to 10 carbon atoms,
• represents a monovalent radical of formula -y-(Y′)n in which:
• y represents a linear or branched C1-C18 polyvalent alkylene radical optionally extended by C1 to C4 oxyalkylene or polyoxyalkylene divalent radicals, which is optionally substituted with a hydroxyl radical,
• Y′ represents an alkenylcarbonyloxy monovalent radical, and
• n is equal to 1, 2 or 3, and
• a is an integer equal to 0, 1 or 2, b is an integer equal to 1 or 2 and the sum a+b=1, 2 or 3;
• and
• ii) optionally units of formula (II) below:
• RaSiO(4-a)/2 (II)
• in which formula:
• the symbols R, which may be identical or different, each represent a linear or branched C1 to C18 alkyl group, a C6 to C12 aryl or aralkyl group, which is optionally substituted, optionally with halogen atoms, and
• a is an integer equal to 0, 1, 2 or 3, and
• 2) an effective amount of at least one type I photoinitiator P of the family of acylphosphine oxide derivatives of formula (III) below:
• in which formula:
• the symbol R5 is a monovalent radical —O—R8 with the symbol R8 being a hydrocarbon-based radical comprising from 1 to 8 carbon atoms;
• the symbol R6 is a phenyl radical optionally substituted with:
• one or more halogen atom(s),
• a hydrocarbon-based radical comprising from 1 to 8 carbon atoms,
• a hydrocarbon-based alkoxy radical comprising from 1 to 8 carbon atoms, and/or
• a hydrocarbon-based thio radical comprising from 1 to 8 carbon atoms;
• and
• the symbol R7 represents a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, a benzyl radical or a phenyl radical optionally substituted with one or more halogen atom(s), a hydrocarbon-based radical comprising from 1 to 8 carbon atoms, a hydrocarbon-based alkoxy radical comprising from 1 to 8 carbon atoms and/or a cycloalkyl radical;
• b) subjecting the dorsal support DO coated with the composition C to ultraviolet radiation in order to cure, by polymerization and/or crosslinking, the composition C to obtain a layer of silicone release coating RC, and
• c) applying at least one adhesive PSA, optionally a pressure-sensitive adhesive PSA on the layer of silicone release coating RC, and then applying a frontal support FR on the adhesive PSA,
• d) preparing an adhesive construction AD by applying, on a frontal support FR, at least one adhesive PSA, optionally one pressure-sensitive adhesive PSA, then joining the adhesive construction AD with the dorsal support DO coated with the composition C prepared in a) in such a way that the adhesive PSA is located between the dorsal support DO and the frontal support FR, and
• e) optionally, applying the composition C on the bottom face SI2 of the dorsal support DO and then subjecting it to ultraviolet radiation to cure, by polymerization and/or crosslinking, the composition C, to obtain a layer of silicone release coating RC on the bottom face SI2 of the dorsal support DO, and subsequently applying at least one adhesive PSA, optionally at least one pressure-sensitive adhesive PSA, on the same layer of silicone release coating RC.