Radiation curable compositions for coating optical fibers

2:

• The radiation curable formulation according to claim 1 in which the Mn of the one or more di- or trifunctional telechelic urethane acrylate oligomers with at least 4 urethane groups (b) is at least 1000 g/mol, or at least 1250 g/mol, or at least 1500 g/mol, and/or wherein the Mn of (b) is 60,000 g/mol or less, or 40,000 g/mol or less, or 30,000 g/mol or less, or between 1000 to 20,000 g/mol, or between 1500 to 15,000 g/mol.

3:

• The radiation curable formulation of claim 1, wherein the one or more di- or trifunctional telechelic urethane acrylate oligomers (b) is a polyether oligomer.

4:

• The radiation curable formulation of claim 1, wherein the Mn of the one or more monofunctional telechelic (meth)acrylate oligomers with 0-5 urethane groups (a) is at least 1000 g/mol, or at least 1250 g/mol, or at least 1500 g/mol, and/or at most 18,000 g/mol, or at most 16,000 g/mol, or at most 15,000 g/mol.

5:

• The radiation curable formulation of claim 1, wherein the one or more monofunctional telechelic (meth)acrylate oligomers according to (a) possesses from 1-3 urethane groups.

6:

• The radiation curable formulation of claim 1, wherein the one or more monofunctional telechelic (meth)acrylate oligomers according to (a) is a polyether oligomer.

7:

• The radiation curable formulation of claim 1, wherein the molar ratio of (b) to (a) is greater than 0.02, or greater than 0.04, or greater than 0.06 and/or less than 1.2, or less than 1.0, or less than 0.8, or less than 0.6.

8:

• The radiation curable formulation of claim 1, wherein (b) and (a) are present in an amount of at least 60 wt. %, or at least 65 wt. %, or at least 70 wt. %, or at least 80 wt. %, or at least 90 wt. %, or at least 95 wt. %, or at least 99 wt. %, relative to the weight of the entire composition.

9:

• The radiation curable formulation of claim 1, wherein the one or more reactive diluent monomer (c) is present in an amount, relative to the weight of the entire composition, in an amount of less than 40 wt. %, or less than 30 wt. %, or less than 20 wt. %, or less than 10 wt. %, or less than 5 wt. %.

10:

• The radiation curable formulation of claim 1, wherein (c) comprises an N-vinyl amide.

11:

• The radiation curable formulation of claim 1, wherein the composition further comprises an oligomeric adhesion promoter.

12:

• The radiation curable formulation of claim 1, wherein the oligomeric adhesion promoter comprises at least 2 urethane groups.

13:

• The radiation curable formulation of claim 11, wherein the oligomeric adhesion promoter is a reaction product of a monofunctional telechelic urethane acrylate oligomer comprising a telechelic hydroxyl group.

14:

• The radiation curable formulation of claim 1, wherein (d) is present in an amount, relative to the weight of the entire composition, of from 0.05-5 wt. %.

15:

• The radiation curable formulation of claim 1, wherein stabilizer is present, relative to the weight of the entire composition, in amount of from 0.05-2 wt. %.

17:

• A cured film comprising the radiation curable formulation of claim 1, wherein, the film possesses a storage modulus (G′) of less than 600 kPa, or from 1 to 550 kPa, or from 10 to 500 kPa, or of less than 300 kPa, or from 1 to 200 kPa, or from 10 to 150 kPa.

18:

• The cured film according to claim 17, wherein the film reaches 30% of the storage modulus increase in less than 1.2 seconds, or less than 1 second.