Self-adhesive article with foam support

1. A self-adhesive article comprising a support layer coated with an adhesive layer, said support layer having an elongation at break ranging from 50 to 1200% and a bulk density ranging from 25 to 1200 kg/m 3 , said adhesive layer being obtained by cross-linking an adhesive composition comprising:

a) a mixture of at least two polymers having at least 20% of dialkoxylated silyl functions, with respect to the total quantity of silyl functions in the mixture of polymers, and comprising:

at least 20% by weight, with respect to the total weight of the mixture of polymers, of at least one polyurethane or at least one polyether comprising two or three hydrolysable dialkoxysilane terminal groups and corresponding to formula (II):

and

at least one polymer corresponding to one of formulae (I), (III) or (IV) wherein:

when a polymer of formula (I) is present, the mixture of polymers comprises up to 80% by weight, with respect to the total weight of the mixture of polymers, of at least one polyurethane or at least one polyether comprising two or three hydrolyzable terminal groups of trialkoxysilane type and corresponding to formula (I):

when a polymer of formula (III) is present, the mixture of polymers comprises up to 15% by weight, with respect to the total weight of the mixture of polymers, of at least one polyurethane or at least one polyether comprising two or three hydrolyzable terminal groups of monoalkoxysilane type and corresponding to formula (III):

when a polymer of formula (IV) is present, the mixture of polymers comprises up to 15% by weight, with respect to the total weight of the mixture of polymers, of at least one polyurethane or at least one polyether comprising one hydrolyzable terminal group of the mono-, di- and-or trialkoxysilane type and corresponding to formula (IV):

in formulae (I), (II), (III), and (IV) above:

B represents one of the two formulae:

 where D and T represent a hydrocarbon radical comprising 2 to 66 carbon atoms, linear, branched, cyclic, alicyclic or aromatic, saturated or unsaturated, optionally comprising one or more heteroatoms,

R 1 represents a divalent hydrocarbon radical comprising 5 to 15 carbon atoms which can be aromatic or aliphatic, linear, branched or cyclic,

R 3 represents a linear or branched divalent alkylene radical comprising 1 to 6 carbon atoms,

R 2 represents a linear or branched divalent alkylene radical comprising 2 to 4 carbon atoms,

R 4 and R 5 , identical or different, each represent a linear or branched alkyl radical comprising 1 to 4 carbon atoms, R 4 optionally being part of a ring,

R 6 represents a hydrocarbon-containing radical comprising 1 to 22 carbon atoms, linear, branched, cyclic, alicyclic or aromatic, saturated or unsaturated, optionally comprising one or more heteroatoms,

n is an integer such that the average molar mass of the polyether block of formula —[OR 2 ] n — ranges from 300 g/mol to 40000 g/mol,

m is an integer such that the average molar mass of the polymer ranges from 600 g/mol to 100000 g/mol,

p is an integer equal to 0, 1 or 2,

f is an integer equal to 2 or 3;

b) at least one tackifier resin, and

c) at least one cross-linking catalyst.

2. The self-adhesive article according to claim 1 , wherein the support layer has a Young's modulus of less than or equal to 300 MPa.

3. The self-adhesive article according to claim 1 , wherein the support layer is in the form of a foam.

4. The self-adhesive article according to claim 1 , wherein the adhesive composition comprises:

from 20 to 85% by weight, with respect to the total weight of the adhesive composition, of a mixture of polymers,

from 15 to 80% by weight, with respect to the total weight of the adhesive composition, of at least one tackifier resin,

from 0.01 to 3% by weight, with respect to the total weight of the adhesive composition, of at least one cross-linking catalyst.

5. The self-adhesive article according to claim 1 , wherein the tackifier resin has a number-average molar mass ranging from 100 Da to 5 kDa and is chosen from:

(i) resins able to be obtained by polymerization of terpene hydrocarbons and phenols, in the presence of Friedel-Crafts catalysts,

(ii) resins able to be obtained by polymerization of alpha-methyl styrene,

(i) rosins of natural or modified origin;

(iv) resins obtained by hydrogenation, polymerization or copolymerization of mixtures of unsaturated aliphatic hydrocarbons having approximately 5, 9 or 10 carbon atoms, originating from petroleum cuts,

(v) terpene resins generally resulting from the polymerisation of terpene hydrocarbons in the presence of Friedel-Crafts catalysts,

(vi) copolymers based on natural terpenes, and

(vii) acrylic resins.

6. A mixture of at least two polymers suitable for use in an adhesive composition, said mixture comprising at least 20% of dialkoxylated silyl functions with respect to the total quantity of silyl functions in the mixture of at least two polymers and comprising:

at least 20% by weight, with respect to the total weight of the mixture, of at least one polymer comprising two or three hydrolyzable terminal groups of dialkoxysilane type and corresponding to formula (II):

and

at least one polymer corresponding to one of formulae (I), (III) or (IV) wherein:

when a polymer of formula (I) is present, the mixture comprises up to 80% by weight, with respect to the total weight of the mixture, of at least one polyurethane or at least one polyether comprising two or three hydrolyzable terminal groups of trialkoxysilane type and corresponding to formula (I):

when a polymer of formula (III) is present, the mixture comprises up to 15% by weight, with respect to the total weight of the mixture, of at least one polyurethane or at least one polyether comprising two or three hydrolyzable terminal groups of monoalkoxysilane type and corresponding to formula (III):

when a polymer of formula (IV) is present, the mixture comprises up to 15% by weight, with respect to the total weight of the mixture of polymers, of at least one polyurethane or at least one polyether comprising one hydrolyzable terminal group of the mono-, di- and-or trialkoxysilane type and corresponding to formula (IV):

in formulae (I), (II), (III), and (IV) above.

7. The mixture of at least two polymers according to claim 6 , comprising:

up to 95% by weight, with respect to the total weight of the mixture, of at least one polymer corresponding to formula (I), and

at least one polymer corresponding to formula (II).

8. The mixture of at least two polymers according to claim 6 , comprising:

from 10 to 85% by weight of at least one polymer corresponding to formula (I), and

from 15 to 90% by weight of at least one polymer corresponding to formula (II), with respect to the total weight of the mixture of at least two polymers.

9. The mixture of at least two polymers according to claim 6 , comprising:

up to 15% by weight, with respect to the total weight of the mixture, of at least one polymer corresponding to formula (III), and

at least one polymer corresponding to formula (II).

10. An adhesive composition suitable for use for the manufacture of a self-adhesive article, comprising:

the mixture of at least two polymers according to claim 6 ,

at least one tackifier resin, and

at least one cross-linking catalyst.

11. The adhesive composition according to claim 10 , comprising.

from 20 to 85% by weight, with respect to the total weight of the adhesive composition, of said mixture of at least two polymers,

from 15 to 80% by weight, with respect to the total weight of the adhesive composition, of at least one tackifier resin,

from 0.01 to 3% by weight, with respect to the total weight of the adhesive composition, of at least one cross-linking catalyst.