Radiation curable compositions for coating optical fiber with enhanced high-speed processability

1. A radiation curable composition for coating an optical fiber comprising:

a reactive oligomer component comprising at least one reactive urethane oligomer comprising a polymerizable group;

wherein at least 20% of a molar fraction of the polymerizable groups in the reactive oligomer component consist of methacrylate groups;

a reactive diluent monomer component comprising reactive diluent monomers having at least one polymerizable group that is able to (co)polymerize with the polymerizable group(s) of the reactive oligomer component; wherein the reactive diluent monomer component comprises a monofunctional acrylate monomer;

wherein at least 50% of a molar fraction of the polymerizable groups of the reactive diluent monomer component consist of acrylate groups, acrylamide groups, N-vinyl amide groups, or mixtures thereof;

a photoinitiator component; and

optionally, an additive component.

2. The radiation curable composition of the previous claim, wherein the reactive urethane oligomer comprises a reaction product of

a polyol compound;

a diisocyanate compound; and

a hydroxyl-functional compound having at least one methacryloyl group.

3. The radiation curable composition according to claim 1 , wherein the reactive urethane oligomer and/or the reactive oligomer component possess a number average molecular weight (Mn) from 6000 g/mol to 20,000 g/mol; wherein Mn is determined according to an SEC method using a triple detector array as described elsewhere herein.

4. The radiation curable composition according to claim 1 , wherein the reactive diluent monomer component comprises-monofunctional acrylate monomers possessing an Mn, theo or an Mn from 86 g/mol to 800 g/mol.

5. The radiation curable composition according to claim 2 , wherein the reactive oligomer component comprises difunctional reactive oligomers.

6. The radiation curable composition according to claim 2 , wherein the hydroxyl-functional compound having at least one methacryloyl group comprises two or greater than two methacryloyl groups.

7. The radiation curable composition of claim 6 , wherein the reactive oligomer comprises, in at least two different locations, the reaction product of a hydroxyl-functional compound possessing two or greater than two methacryloyl groups.

8. The radiation curable composition according to claim 6 , wherein the reactive oligomer component comprises trifunctional and/or tetrafunctional reactive oligomers.

9. The radiation curable composition according to claim 6 , wherein the hydroxyl-functional compound having two or greater than two methacryloyl groups comprises 1,2-glycerol dimethacrylate, 1,3-glycerol dimethacrylate, or combinations thereof.

10. The radiation curable composition according to claim 1 , wherein at least one polymerizable group is a polymerizable backbone group.

11. The radiation curable composition according to claim 1 , wherein the hydroxyl-functional compound having at least one methacryloyl group comprises 2-hydroxyethyl methacrylate, caprolactone 2-(methacryloyloxy)ethyl ester, or glycerol monomethacrylate, or combinations thereof.

12. The radiation curable composition according to claim 1 , wherein the reactive oligomer comprises a plurality of polymerizable groups, wherein the polymerizable groups comprise polymerizable endgroups and polymerizable backbone groups.

13. The radiation curable composition according to claim 12 , wherein the reactive oligomer component comprises pentafunctional reactive oligomers.

14. The radiation curable composition according to claim 1 , wherein, by molar fraction, at least 30% of the polymerizable groups of the reactive oligomer component consist of methacrylate groups.

15. The radiation curable composition according to claim 1 , wherein the polymerizable groups of the reactive oligomer component consist of or consist essentially of methacrylate groups.

16. The radiation curable composition according to claim 1 , wherein the polymerizable groups of the reactive diluent monomer component consist of or consist essentially of acrylate groups.

17. The radiation curable composition according to claim 1 , wherein a molar fraction of methacrylate groups present in the entire composition to a total amount of polymerizable groups present in the entire composition is from 2% to 16%.

18. The radiation curable composition according to claim 17 , wherein a molar ratio of acrylate groups to methacrylate groups in the entire composition is from 4:1 to 50:1.

19. The radiation curable composition according to claim 2 , wherein, relative to the entire weight of the composition,

the reactive oligomer component is present in an amount from 20 wt. % to 95 wt. %;

the reactive diluent monomer component is present in an amount from 4 wt. % to 75 wt. %;

the photoinitiator is present in an amount from 0.25 wt. % to 7 wt. %; and

the additives are present in an amount from 0 wt. % to 50 wt. %.

20. The radiation curable composition according to claim 19 , wherein at least one of conditions (a), (b), (c), or (d) applies:

(a) the polyol compound comprises a polyether, polyester, polycarbonate, polyamide, polycaprolactone, or acrylic moiety;

(b) the diisocyanate compound comprises isophorone diisocyanate, 2,4-isomer toluene diisocyanate, 2,4- and/or 4,4′-methylenedicyclohexyl diisocyanate, methylenediphenyl diisocyanate, tetramethylxylene diisocyanate, (hydrogenated) xylylene diisocyanate, 1,5-pentane diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate, or hexamethylene diisocyanate, or combinations thereof;

(c) the hydroxyl-functional compound having at least one methacryloyl group is a methacrylate compound, and comprises 2-hydroxyethyl methacrylate, caprolactone 2-(methacryloyloxy)ethyl ester, or combinations thereof; and/or

(d) the compound having a hydroxyl group and no polymerizable group comprises n-butanol, 2-ethyl hexanol, benzyl alcohol, or combinations thereof.

21. The radiation curable composition according to claim 19 , wherein the reactive diluent monomer component comprises 2-ethylhexyl acrylate, 2-phenoxyethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, n-vinyl pyrrolidone, acryloyl morpholine, dimethylacryl-amide, n-vinylcaprolactam, ethoxylated 2-phenoxy ethyl acrylate, 4-hydroxy butyl acrylate, lauryl acrylate, isobornyl acrylate, caprolactone acrylate, isodecyl acrylate, or ethoxylated nonylphenol acrylate, or mixtures thereof.

22. The radiation curable composition according to claim 19 , wherein the photoinitiator comprises, consists of, or consists essentially of 4-methyl benzophenone, 2,4,6-trimethyl benzophenone, dimethoxybenzophenone, 1-hydroxycyclohexyl phenyl ketone, phenyl(1-hydroxyisopropyl)ketone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, and 4-isopropylphenyl(1-hydroxyisopropyl)ketone, benzil dimethyl ketal, oligo-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone]; 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl phenyl, bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 4-benzoyl-4′-methyl diphenyl sulphide, 4,4′-bis(diethylamino)benzophenone, or 4,4′-bis(N,N-dimethylamino)benzophenone (Michler's ketone).

23. The radiation curable composition according to claim 19 , wherein the additives comprise an adhesion promoter.

24. The radiation curable composition according to claim 23 , wherein the adhesion promoter comprises mercaptopropyltrimethoxysilane, trimethoxysilyl propyl acrylate, tetraethoxysilane, or 3 trimethoxysilyl propane-1-thiol.

25. The radiation curable composition according to claim 19 , wherein the additives comprise an antioxidant, a polymerization inhibitor, a photosensitizer, a carrier surfactant, a tackifier, a catalyst, a stabilizer, a surface agent, and/or an optical brightener.

26. The radiation curable composition according to claim 1 , wherein the composition possesses a T 30%, modulus max value from 0.3 to 1.5 seconds, wherein the T 30%, modulus max value is measured by procedures as described herein, and/or wherein the composition possesses a maximum modulus (G′) value of less than 0.5 MPa, wherein the G′ value is measured by procedures as described herein.

27. The radiation curable composition according to claim 1 , wherein in a copolymerization between the compound having at least one methacryloyl group and 2-hydroxyethyl acrylate (HEA),

a self-reactivity ratio of the compound having at least one methacryloyl group (R 1 ) is between 1 and 5, or between 1.4 and 3.5;

wherein, R 1 is determined according to multivariate analysis using the infrared spectra of the copolymer input compounds.

28. The radiation curable composition according to claim 27 , wherein a reactivity ratio of the compound having at least one methacryloyl group with HEA (R 2 ) is from 0.1 to 0.5, or from about 0.15 to about 0.35;

wherein, R 2 is determined according to multivariate analysis using the infrared spectra of the copolymer input compounds.

29. The radiation curable composition according to claim 28 , wherein

R

1

R

2

is from 3 to 11.

30. The radiation curable composition according to claim 1 , wherein, by molar fraction, at least 50% of the polymerizable groups of the reactive oligomer component consist of methacrylate groups; and at least 90% of the molar fraction of the polymerizable groups of the reactive diluent monomer component consist of acrylate groups, acrylamide groups, N-vinyl amide groups, or mixtures thereof.