Elastomeric compositions and their applications
A condensation curable gel composition is the disclosed. The composition comprises: (i) at least one condensation curable silyl terminated polymer having at least one hydrolysable and/or hydroxyl functional group(s) per molecule; (ii) a cross-linker selected from the group of a silicone, an organic polymer, a monosilane or a disilane molecule which contains at least two hydrolysable groups per molecule; and (iii) a condensation catalyst selected from the group of titanates, zirconates or tin (II). The molar ratio of hydroxyl and/or hydrolysable group(s) in polymer (i) to hydrolysable groups from component (ii) is between 0.5:1 and 1:1 using a monosilane cross-linker or 0.75:1 to 3:1 using disilanes. The titanates and zirconates comprise M-OR functions where M is titanium or zirconium and R is an aliphatic hydrocarbon group. The molar ratio of M-OR or tin (II) functions to the hydroxyl and/or hydrolysable groups in polymer (i) is comprised between 0.01:1 and 0.5:1.
1. A medical application comprising a gel, wherein the gel is the reaction product of a condensation curable gel composition, the composition comprising:
(i) at least one condensation curable silyl terminated polymer having at least one hydrolysable and/or hydroxyl functional group(s) per molecule;
(ii) a cross-linker selected from the group of a monosilane or a disilane molecule which contains at least two hydrolysable groups per molecule; and
(iii) a condensation catalyst selected from the group of titanates, zirconates or tin (II);
wherein the molar ratio of hydroxyl and/or hydrolysable group(s) in polymer (i) to hydrolysable groups from component (ii) is between 0.5:1 and 1:1 using a monosilane cross-linker or 0.75:1 to 3:1 using disilanes;
wherein the titanates and zirconates comprise M-OR functional groups where M is titanium or zirconium and R is an aliphatic hydrocarbon group; and
wherein the molar ratio of M-OR functional groups to the hydroxyl and/or hydrolysable group(s) in polymer (i) is comprised between 0.01:1 and 0.5:1.
2. The medical application comprising the gel in accordance with claim 1 , wherein prior to cure, the composition is stored in two parts having polymer (i) and cross-linker (ii) in one part, and polymer (i) and catalyst (iii) in the other part.
3. The medical application comprising the gel in accordance with claim 1 , wherein prior to cure, the composition is stored in two parts having cross-linker (ii) in one part, and polymer (i) and catalyst (iii) in the other part.
4. The medical application comprising the gel in accordance with claim 1 , wherein prior to cure, the composition is stored in two parts having a first polymer (i) and cross-linker (ii) in one part, and a second polymer (i) and catalyst (iii) in the other part.
5. The medical application comprising the gel in accordance with claim 1 , wherein the molar ratio of M-OR functional groups to the hydroxyl and/or hydrolysable group(s) in polymer (i) is comprised between 0.02:1 and 0.2:1.
6. The medical application comprising the gel in accordance with claim 1 , the composition further comprising a polymer curable by hydrosilylation, a hydrosilylation cross-linker, and a hydrosilylation catalyst.
7. The medical application comprising the gel in accordance with claim 1 , wherein the cross-linker (ii) comprises the monosilane.
8. The medical application comprising the gel in accordance with claim 7 , wherein the molar ratio of hydroxyl and/or hydrolysable group(s) in polymer (i) to hydrolysable groups from component (ii) is between 0.5:1 and 0.75:1.
9. The medical application comprising the gel in accordance with claim 1 , wherein the cross-linker (ii) comprises the disilane molecule.
10. The medical application comprising the gel in accordance with claim 9 , wherein the molar ratio of hydroxyl and/or hydrolysable group(s) in polymer (i) to hydrolysable groups from component (ii) is between 0.75:1 to 1.5:1.
11. The medical application comprising the gel in accordance with claim 1 , wherein:
i) the polymer (i) has at least two hydrolysable and/or hydroxyl functional groups per molecule;
ii) the cross-linker (ii) contains at least three hydrolysable groups per molecule; or
iii) both i) and ii).
12. The medical application comprising the gel in accordance with claim 11 , wherein the polymer (i) has at least two hydrolysable and/or hydroxyl functional groups per molecule.
13. The medical application comprising the gel in accordance with claim 11 , wherein the cross-linker (ii) contains at least three hydrolysable groups per molecule.
14. The medical application comprising the gel in accordance with claim 1 , wherein the gel is for drug delivery, the gel is for wound care, a soft skin adhesive comprises the gel, a transdermal patch comprises the gel, and/or the gel is for the controlled release of medicaments.