Polyurea systems, processes for preparing the same and use thereof for postoperative adhesion barriers

1. A post operative adhesion barrier comprising a polyurea system comprising:

(a) an amino-functional aspartic ester of the general formula (I)

wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH 2 ) n , R 1 and R 2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2; and

(b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting:

(b1) an aliphatic isocyante; and

(b2) a polyol component having a number average molecular weight of ≧400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof, and

wherein the post operative adhesion barrier is a medical adhesion barrier,

wherein the post operative adhesion barrier is biodegradable within 6 month forming degradation products, and wherein the degradation products have no cell and tissue toxicity.

2. The post operative adhesion barrier according to claim 1 , wherein the polyurea system comprises: (c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas.

3. The post operative adhesion barrier according to claim 1 , wherein the polyurea system further comprises: (d) a reaction product of an isocyanate functional prepolymer according to (b) and an amino-functional aspartic ester according to (a).

4. The post operative adhesion barrier according to claim 1 , wherein the polyurea system further comprises: (d) a reaction product of an isocyanate functional prepolymer according to (b) and an amino-functional aspartic ester according to (a).

5. The post operative adhesion barrier according to claim 1 , wherein the polyurea system further comprises: (d) a reaction product of an isocyanate functional prepolymer according to (b); an amino-functional aspartic ester according to (a); and (c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas.

6. The post operative adhesion barrier according to claim 1 , wherein the polyurea system further comprises: (d) a reaction product of an isocyanate functional prepolymer according to (b); an amino-functional aspartic ester according to (a); and (c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas.

7. The post operative adhesion barrier according to claim 1 , wherein the polyol component has a hydroxyl number of 30 to 140 mg KOH/g, an acid number of 0.05 to 10 mg KOH/g and a DIN 53019 shear viscosity at 23° C. of 200 to 8000 mPas.

8. The post operative adhesion barrier according to claim 1 , wherein the polyol component comprises polyether polyols having a number average molecular weight of 100 to 2000 g/mol and having at least some of ether groups therein derived from ethylene oxide.

9. The post operative adhesion barrier according to claim 1 , wherein the polyol component comprises ≦50% by weight of polyether polyols based on the polyol component.

10. The post operative adhesion barrier according to claim 1 , wherein the polyol component has an ester group concentrations of 0.5 to 5.5 moles per kg.

11. The post operative adhesion barrier according to claim 2 , wherein the organic filler comprises a hydroxy-functional polyether polyol compound.

12. The post operative adhesion barrier according to claim 1 , wherein the polyurea system further comprises: (c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas, and (d) a reaction product of an isocyanate functional prepolymer according to (b) and an amino-functional aspartic ester according to (a); wherein the polyol component has a hydroxyl number of 30 to 140 mg KOH/g, an acid number of 0.05 to 10 mg KOH/g and a DIN 53019 shear viscosity at 23° C. of 200 to 8000 mPas; wherein the polyol component comprises ≦50% by weight of polyether polyols based on the polyol component; and wherein the organic filler comprises a hydroxy-functional polyether polyol compound.

13. A process for preparing a polyurea system, the process comprising:

(i) providing (a) an amino-functional aspartic ester of the general formula (I)

wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH 2 ) n , R 1 and R 2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2;

(ii) providing (b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolyrner prepared by reacting:

(b1) an aliphatic isocyante; and

(b2) a polyol component having a number average molecular weight of ≧400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof; and

(iv) mixing the (a) amino-functional aspartic ester and the (b) isocyanate functional prepolymer in a ratio of free or blocked amino groups to free NCO groups of 1:1,

utilizing the polyurea system in a post operative adhesion barrier, wherein the post operative adhesion barrier is biodegradable with 6 month forming degradation products, and wherein the degradation products have no cell and tissue toxicity.

14. The process according to claim 13 , further comprising: (iii) providing (c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas; and wherein the (c) organic filler is mixed with the (a) amino-functional aspartic ester and the (b) isocyanate functional prepolymer at a weight ratio of organic filler to amino-functional aspartic ester of 0:1 to 20:1.

15. A polyurea system prepared according to the process of claim 13 .

16. A polyurea system prepared according to the process of claim 14 .

17. A method comprising:

(i) providing cell tissue to be treated;

(ii) providing the post operative adhesion barrier according to claim 1 ; and

(iii) contacting the cell tissue with the post operative adhesion barrier.

18. A dispensing system comprising a first chamber and a second chamber; wherein the first chamber comprises (a) an amino-functional aspartic ester of the general formula (I)

wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH 2 ) n , R 1 and R 2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2; and wherein the second chamber comprises (b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting:

(b1) an aliphatic isocyante; and

(b2) a polyol component having a number average molecular weight of ≧400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof,

and wherein when the (a) amino-functional aspartic ester and the (b) isocyanate functional prepolymer are mixed to form a polyurea system which, when utilized in a post operative adhesion barrier, the post operative adhesion barrier is biodegradable with 6 month forming degradation products, and wherein the degradation products have no cell and tissue toxicity.

19. A post operative adhesion barrier comprising a polyurea system comprising:

(a) and amino-functional aspartic ester of the general formula (I)

wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH 2 ) n , R 1 and R 2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents and integer of at least 2; and

(b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting:

(b1) an aliphatic isocyante; and

(b2) a polyol component having a number average molecular weight of ≧400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof;

wherein the polyurea system is configured to be a medical barrier to adhesion,

and wherein the post operative adhesion barrier is biodegradable with 6 month forming degradation products, and wherein the degradation products have no cell and tissue toxicity.

20. A post operative adhesion barrier comprising a polyurea system consisting essentially of:

(a) an amino-functional aspartic ester of the general formula (I)

wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH 2 ) n , R 1 and R 2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2; and

(b) an ixocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting:

(b1) an aliphatic isocyante; and

(b2) a polyol component having a number average molecular weight of ≧400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof; and

(c) an organic filler having a DIN 53019 viscosity at 23° C. of 10 to 6000 mPas and having no cytotoxicity according to ISO 10993,

wherein the post operative adhesion barrier is a medical adhesion barrier,

wherein the post operative adhesion barrier is biodegradable with 6 month forming degradation products, and wherein the degradation products have no cell and tissue toxicity.