Heat fusible oil gels
The present invention is directed to a composition for a gel useful in fiber optic cable which has the normal consistency of a grease but which, if desired, will become a rubbery coherent gel upon heating; a method of making the heat-fusible gel, and a method of making a spliceable fiber optic cable, and a fiber optic cable. In the broadest sense, a heat-fusible oil gel composition for fiber optic cable is disclosed, comprising: from 50 to 80 wt. % of a grease-like gel based on a hydrocarbon oil containing from 2 to 10 wt. % of an S-EB or S-EP diblock polymer, or a mixture of these diblock copolymers, and from 20 to 50 wt. % of a grease-like gel based on a polar oil containing from 5 to 25 wt. % of an S-EB-S or S-EP-S triblock copolymer, or a mixture of these triblock copolymers.
1. A heat fusible oil gel composition comprising:
a) from 50 to 80 wt. % of a gel based on a hydrocarbon oil containing from 2 to 10 wt. % of an S-EB or S-EP diblock copolymer, or a mixture thereof, and
b) from 20 to 50 wt. % of a gel based on a polar oil containing from 5 to 25 wt. % of an S-EB-S or S-EP-S triblock copolymer, or a mixture thereof, where S, EB, and EP represent blocks of polystyrene, hydrogenated polybutadiene and hydrogenated polyisoprene, respectively, and wherein said hydrocarbon oil is an aromatic-free oil containing paraffinic and/or naphthenic species.
2. The heat fusible oil gel composition of claim 1 wherein said polar oil is an ether, ester or ketone oil.
3. The heat fusible oil gel composition of claim 1 wherein said polar oil is hydroxylated soybean oil or an ester of pentaerythritol and linear saturated fatty acids.
4. A method of producing a heat fusible oil gel composition comprising:
a) making a gel based on a hydrocarbon oil by mixing from 2 to 10 wt. % of a diblock polymer into the oil for about 30-60 minutes at about 120-140° C. with a high shear mixer,
b) making a gel based on a polar oil by mixing from 5 to 25 wt. % of a triblock polymer into the oil for about 30-60 minutes at about 120-140° C. with a high shear mixer, and
c) mixing about 50 to about 80 wt. % of the gel based on a hydrocarbon oil and about 20 to about 50 wt. % of the gel based on a polar oil at near room temperature with a low shear mixer.
5. A method of producing a spliceable fiber optic cable that can be easily spliced without spilling oil comprising:
placing a fiber optic waveguide into a flexible sleeve,
filling said sleeve with said heat fusible oil gel composition of claim 1 ,
when it is desirable to splice the optic fiber cable, the following steps are completed heating said filled sleeve in an area where the optical fiber waveguide and sleeve are to be cut, until said heat fusible oil gel composition solidifies, and
cutting said glass fiber and sleeve in said solidified area to splice it to another spliceable fiber optic cable.
6. The method of claim 5 wherein said heating is conducted at a temperature between about 120 and 150° C. for between about 5 and 60 minutes.
7. A fiber optic cable comprising: at least one fiber optic wave guide, a flexible sheath surrounding said at least one fiber optic wave guide and a heat fusible oil gel composition of claim 1 within said sheath, surrounding said at least one fiber optic wave guide.
8. A method of producing a spliceable fiber optic cable comprising:
placing at least one fiber optic waveguide into a flexible sleeve,
filling said sleeve with a heat fusible oil gel composition comprising 50 to 80 wt. % of a hydrocarbon oil gel containing from 2 to 10 wt. % of an S-EB or S-EP diblock polymer or a mixture thereof, and from 20 to 50 wt. % of a polar oil gel containing 5 to 25 wt. % of an S-EB-S or S-EP-S triblock polymer, or a mixture of these,
wherein said heat fusible oil gel is positioned between the at least one fiber optic waveguide and the flexible sleeve.
9. The heat fusible oil gel composition of claim 1 wherein S has a molecular weight from 3.0 to about 60 kg/mol, EB has a molecular weight from 30 to about 300 kg/mol, and EP has a molecular weight from about 30 to about 300 kg/mol.
10. The heat fusible oil gel composition of claim 1 wherein the amount of styrene of the triblocks copolymer is greater than about 20 wt. %.
11. The heat fusible oil gel composition of claim 1 wherein the amount of styrene in the diblock copolymer is from about 28 to about 30 wt. %.
12. The heat fusible oil gel composition of claim 1 wherein the diblock copolymer and triblock copolymer have been selectively hydrogenated and at least about 95% of the EB and EP double bonds have been reduced and between 0 and 10% of the styrene double bonds have been reduced.
13. The heat fusible oil gel composition of claim 1 wherein the vinyl content of the EB block is from about 30 to about 80 mol %.
14. The heat fusible oil gel composition of claim 1 wherein the hydrocarbon oil is a mineral oil or a synthetic oil.
15. The heat fusible oil gel composition of claim 1 wherein the gel based on a hydrocarbon oil further comprises a hydrophobic fumed silica in an amount up to about 7.5 wt. % based on the weight of the hydrocarbon oil gel.
16. The heat fusible oil gel composition of claim 1 wherein the gel based on a polar oil further comprises a hydrophilic fumed silica in an amount up to about 2.5 wt. % based on the weight of the polar oil gel.
17. The method of claim 4 wherein the diblock copolymer is S-EB or S-EP where S is a block of polystyrene, EB is a block of hydrogenated polybutadiene, and EP is a block of hydrogenated polyisoprene.
18. The method of claim 4 wherein the triblock copolymer is S-EB-S or S-EP-S where S is a block of polystyrene, EB is a block of hydrogenated polybutadiene, and EP is a block of hydrogenated polyisoprene.
19. The method of claim 4 wherein the hydrocarbon oil is an aromatic-free oil containing paraffinic and/or naphthenic species and is a mineral oil or a synthetic oil and the polar oil is an ether, ester or ketone oil.