D1378 CA RADIATION CURABLE PRIMARY COATING FOR OPTICAL FIBER

• US 20080226911A1
• Filed: 12/13/2007
• Published: 09/18/2008
• Est. Priority Date: 12/14/2006
• Status: Abandoned Application

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Inventors: Wu, Xiaosong, Murphy, Edward J., Zimmerman, John M., Schmid, Steven R., Tortorello, Anthony Joseph
• Application Number:
  US11/955,525
• Publication Number:
  US 20080226911A1
• Time in Patent Office: Days
• US Class Current: 428/392
• CPC Class Codes: C03C 25/106 Single coatings
• CPC Class Codes: C03C 25/1065 Multiple coatings
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08G 18/724 Combination of aromatic polyisocyanates with (cyclo)aliphatic polyisocyanates
• CPC Class Codes: C08G 18/755 and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• CPC Class Codes: C08G 18/7621 being toluene diisocyanate including isomer mixtures
• CPC Class Codes: C09D 175/16 having terminal carbon-to-carbon unsaturated bonds
• CPC Class Codes: G02B 6/02395 Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104
• CPC Class Codes: Y10T 428/2964 Artificial fiber or filament

Abstract

Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and methods for the preparation of coated optical fibers. A radiation curable Primary Coating composition comprising: an oligomer; a diluent monomer; a photoinitiator; an antioxidant; and an adhesion promoter; wherein said oligomer is the reaction product of: a hydroxyethyl acrylate; an aromatic isocyanate; an aliphatic isocyanate; a polyol; a catalyst; and an inhibitor, wherein said catalyst is an organo bismuth catalyst; wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and wherein a cured film of said radiation curable coating composition has a peak tan delta Tg of from about −25° C. to about −45° C.; and a modulus of from about 0.50 MPa to about 1.2 MPa.

Claims

1. A radiation curable Primary Coating composition comprising:

A) an oligomer;

B) a diluent monomer;

C) a photoinitiator;

D) an antioxidant; and

E) an adhesion promoter;

wherein said oligomer is the reaction product of;

i) a hydroxyethyl acrylate;

ii) an aromatic isocyanate;

iii) an aliphatic isocyanate;

iv) a polyol;

v) a catalyst; and

an

vi) inhibitor,

wherein said catalyst is an organo bismuth catalyst;

wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and

wherein a cured film of said radiation curable coating composition has a peak tan delta Tg of from about −

25°

C. to about −

45°

C.; and

a modulus of from about 0.50 MPa to about 1.2 MPa.

2. A process for coating an optical fiber, the process comprising:

a) operating a glass drawing tower to produce a glass optical fiber; and

b) coating said glass optical fiber with the radiation curable Primary Coating composition of claim 1.

3. The process of claim 2 wherein the glass drawing tower is operated at a line speed of between about 750 meters/minute and about 2100 meters/minute to produce a glass optical fiber.

4. A wire coated with a first and second layer, wherein the first layer is a cured radiation curable Primary Coating of claim 1 that is in contact with the outer surface of the optical fiber and the second layer is a cured radiation curable Secondary Coating in contact with the outer surface of the Primary Coating,

wherein the cured Primary Coating on the wire has the following properties after initial cure and after one month aging at 85°

C. and 85% relative humidity;

A) a % RAU of from about 84% to about 99%;

B) an in-situ modulus of between about 0.15 MPa and about 0.60 MPa; and

C) a Tube Tg, of from about −

25°

C. to about −

55°

C.

5. An optical fiber coated with a first and second layer, wherein the first layer is a cured radiation curable Primary Coating of claim 1 that is in contact with the outer surface of the optical fiber and the second layer is a cured radiation curable Secondary Coating in contact with the outer surface of the Primary Coating,

wherein the cured Primary Coating on the optical fiber has the following properties after initial cure and after one month aging at 85°

C. and 85% relative humidity;

A) a % RAU of from about 84% to about 99%;

B) an in-situ modulus of between about 0.15 MPa and about 0.60 MPa; and

C) a Tube Tg, of from about −

25°

C. to about −

55°

C.

6. A radiation curable Primary Coating composition comprising:

an oligomer;

a diluent monomer;

a photoinitiator;

an antioxidant; and

an adhesion promoter;

wherein said oligomer is the reaction product of;

i) a hydroxyethyl acrylate;

ii) an aromatic isocyanate;

iii) an aliphatic isocyanate;

iv) a polyol;

v) a catalyst; and

an vi) inhibitor,

wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol;

wherein a cured film of said radiation curable Primary Coating composition has a peak tan delta Tg of from about −

25°

C. to about −

45°

C.; and

a modulus of from about 0.50 MPa to about 1.2 MPa and

wherein said catalyst is selected from the group consisting of sulfonic acids, including but not limited to dodecylbenzene sulfonic acid, CAS 27176-87-0; and

methane sulfonic acid, GAS 75-75-2;

amino or organo-base catalysts, including, but not limited to;

1,2-dimethylimidazole, CAS 1739-84-0; and

diazabicyclo[2.2.2]octane (DABCO), CAS 280-57-9 (strong base); and

triphenyl phosphine;

alkoxides of zirconium and titanium, including, but not limited to zirconium butoxide, (tetrabutyl zirconate) CAS 1071-76-7; and

titanium butoxide, (tetrabutyl titanate) CAS 5593-70-4; and

ionic liquid phosphonium, imidazolium, and pyridinium salts, such as, but not limited to, trihexyl(tetradecyl)phosphonium hexafluorophosphate, CAS No. 374683-44-0;

1-butyl-3-methylimidazolium acetate, CAS No. 284049-75-8; and

N-butyl-4-methylpyridinium chloride, CAS No. 125652-55-3; and

tetradecyl(trihexyl)phosphonium.