Resumen
The invention relates to a novel adhesive technology and more particularly, to a separable fastener system based on the functionalization of two copolymers, that could be functionalized and then processed on a surface, or the opposite, processed on a surface and then functionalized in order to generate high hetero-/homo-adhesion ratio and low moisture sensitivity, due to a good combination of H-bonding and ionic interactions, preferably functionalizing the polymeric surface without modifying the bulk material, as well as its procedure for obtainment and their uses as adhesive.
Reivindicaciones
1. A separable fastener system characterized in that it comprises two elements, a first element and a second element, wherein each of the first element and the second element comprises a hydrophobic polymer surface grafted with a positive ionic compound or a negative ionic compound, wherein the positive ionic compound or the negative ionic compound of the first element is configured, in use, to be bound to the negative ionic compound or the positive ionic compound, respectively, of the second element. 2. The separable fastener system according to claim 1, wherein the hydrophobic polymer surface comprises a copolymer obtained from polymerization of two different olefin monomers M1 and M2, one of them comprising a pentafluorophenyl group. 3. The separable fastener system according to any of claims 1 or 2, wherein the hydrophobic polymer is obtained by polymerization of two different olefin monomers M1 and M2, being one of them pentafluorostyrene. 4. The separable fastener system according to claim 2 or 3, wherein the other monomer is selected from aromatic or aliphatic acrylic or methacrylic monomer; and wherein M2 monomer is an olefin substituted by a pentafluorophenyl group, preferably pentafluorophenyl acrylic monomer. 5. The separable fastener system according to any of claims 2 to 4, wherein the distribution of M1 and M2 along the polymer chain is random, alternate or in the form of block copolymers. 6. The separable fastener system according to any claims 2 to 5, wherein M1 monomer is aliphatic acrylate monomer of the general formula: <img class="EMIRef" id="6b7d9ad0-a1ab-4a12-8b92-99b7f25644ac-ib0017" /> wherein n1 is an integer between 1 and 12; and/or M2 monomer is pentafluorostyrene of the general formula: <img class="EMIRef" id="6b7d9ad0-a1ab-4a12-8b92-99b7f25644ac-ib0018" /> 7. The separable fastener system according to any of claims 1 to 6, wherein the polymer has the following formula: <img class="EMIRef" id="6b7d9ad0-a1ab-4a12-8b92-99b7f25644ac-ib0019" /> wherein: n1 is 1-12, and n2 and n3 can be any number, reaching average molecular weights from 100 to 100.000. 8. The separable fastener system according to any of claims 1 to 7, wherein the negative ionic compound grafted in the polymer surface of the second element are selected from a compound containing carboxylate, sulfonate or phosphate ions (C) and/or the positive ionic compound grafted in the polymer surface of the first element are selected from a compound containing amidinium groups (A), wherein the compound (C) and (A) are covalently bonded to the hydrophobic polymer. 9. Separable fastener system according to claim 8, wherein the compound carboxylate C has the general formula: <img class="EMIRef" id="6b7d9ad0-a1ab-4a12-8b92-99b7f25644ac-ib0020" /> (X<1>-R2)<n5> substituents at ortho- or meta positions with respect to the carboxylate group, wherein: n5 is an integer between 0 to 4, wherein: X<1> is O, N or S, R2 is selected from an c1-c6 alkyl group, phenyl, benzyl or fluorocarbon chain with formula C<n>F<2n+1> wherein n is an integer between 1 to 6; and wherein X2-(CH<2>)<n4>-Nu is a substituent at ortho-, meta- or para- position with respect to the carboxylate, preferably para-, wherein Nu is selected from thiol (-SH), an alcohol (-OH) and an amine (-NH<2>), more preferably thiol, X<2> is selected from -CH<2>-, - O-, -N-, and -S-, and n4 is an integer between 1 to 12 10. The separable fastener system according to any of claims 8 to 11, wherein the compound A is a guanidinium or an amidinium derivative and has the general formula: <img class="EMIRef" id="6b7d9ad0-a1ab-4a12-8b92-99b7f25644ac-ib0021" /> (X<1>-R2)<n5> substituents at ortho- or meta positions with respect to the amidinium/guanidinium group, wherein: n5 is an integer between 0 to 4, wherein: X1 is O, N or S, R2 is selected from an c1-c6 alkyl group, phenyl, benzyl or fluorocarbon chain with formula C<n>F<2n+1> wherein n is an integer between to 6; and wherein X2-(CH<2>)<n4>-Nu is a substituent at ortho-, meta- or para- position with respect to the amidinium/guanidinium, preferably para-, wherein Nu is selected from thiol (-SH), an alcohol (-OH) and an amine (NH2), more preferably thiol, X<2> is selected from -CH<2>-,- O-, -N-, and -S-,and wherein Y = C or N; more preferably Y=C; and wherein R3 is selected from hydrogen (H), c1-c6 alkyl group, phenyl or benzyl. 11. A process to obtain the separable fastener system described in claims 1-10, characterized in that it comprises the following steps: I. synthesizing a polymer by a polymerization reaction, preferably the polymerization is an aqueous emulsion radical co-polymerization method; and II. grafting a positive ionic compound or a negative ionic compound on the polymer obtained in step (I), wherein the grafting is selected from a grafting reaction in solution and grafting reaction on film surface. 12. The process according to claim 11, wherein the polymerization method of step (I) is aqueous emulsion radical polymerization method comprising the following steps: a) adding monomer ratios from 0/100 to 100/0 to a solution containing the emulsifier in deionized water and purging the mixture with inert gas, preferably Argon; b) heating the mixture obtained in (a) to a temperature of between 50 ºC and 80 ºC, and then injecting the initiator in a shot; c) reacting for a time between 12 h and 36 h under constant stirring the heated mixture obtained in (b); a) extracting the polymer or copolymers obtained in (c), concentrating, and then washing the polymer 2-3 times with methanol and filtering and dried under vacuum of between 100 and 1 mbar. 13. The process according to any of claims 11 or 12, wherein the step (b) of the present invention the grafting is the reaction on film surface comprising the following steps: i. dissolving the copolymer obtained before in haloform and evaporating the haloform; ii. adding the positive ionic compound or a negative ionic compound in methanol and dropwise adding to the copolymer of the step (a); iii. reacting the mixture for at least 45 hours in a temperature of between 20 and 40 ºC in an inert atmosphere; iv. washing with acidic methanol, methanol and drying under vacuum of between 100 and 1 mbar. 14. Use of the separable fastener system according to any of claims 1 to 10 as an adhesive coating of two different planar surfaces of different or identical nature element with weight up to 0.5 kg selected from metal, glass, or plastic. 15. An article comprising two substrates coated of the separable fastener system according to any claims 1 to 10, wherein the substrates are selected independently each one from glass, paper, wood, plastic, brick or metal.
