Mineral oil extended polyurethane system containing a coupling agent for decontaminating and sealing the interior spaces of an insulated electrical device

Abstract

This invention provides a method of sealing and purging contaminants from the internal free spaces of an insulated electrical device by forcing into said free spaces a low viscosity material that acts to displace fluid contaminants from within said free spaces. The material later cures in situ to form a hydrophobic seal with good electrical properties. Also disclosed herein is a method for rehabilitating waterlogged plastic insulated multiconductor communications cables of the type employed in telephone systems.

We claim: 
     
       1. A .Iadd.cured, cross-linked, .Iaddend.mineral oil extended polyurethane .[.system.]. comprising the reaction product of an isocyanate terminated prepolymer with a polyol .Iadd.selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof, .Iaddend.in the presence of a mineral .Iadd.oil .Iaddend.and a liquid coupling agent for compatibilizing said mineral oil with said polyurethane, said .Iadd.mineral oil extended .Iaddend.polyurethane .[.system.]. containing from about 8 to about 20 parts of .[.said urethane polymer.]. .Iadd.polyurethane.Iaddend., from about 60 to about 75 parts mineral oil and from about 10 to about 25 parts of .[.coupler.]. .Iadd.coupling agent.Iaddend., all parts expressed on a weight basis, said liquid coupling agent being miscible in all proportions with said mineral oil, said coupling agent .Iadd.being .Iaddend.selected from the group consisting of a ketone and an ester .[.of an organic compound selected from the group consisting of a diol and a diacid.]., said agent having a boiling temperature above 220° F., a solubility parameter between 7.0 and 9.5 and a hydrogen bonding index number in the range from .[.8.2 to 8.8.]. .Iadd.6.0 to 12.0, and said agent being non-reactive with the prepolymer and the polyol.Iaddend., said isocyanate terminated prepolymer .Iadd.being prepared by reacting a polyisocyanate .Iaddend.selected from the group consisting of cycloaliphatic diisocyanate, aliphatic diisocyanate and aromatic diisocyanate .[.; said.]. .Iadd.with a .Iaddend.polyol selected from the group consisting of castor oil.Iadd., .Iaddend..[.and.]. polyether .Iadd.polyols, hydroxyl bearing homopolymers of butadiene, hydroxy bearing copolymers of butadiene and styrene, and combinations thereof .Iaddend.wherein at least .[.one of said urethane forming reactants include a hydroxy bearing polybutadiene constituent.]. .Iadd.a portion of the polyol used in the preparation of the polyurethane is selected from the group consisting of hydroxyl bearing homopolymers of butadiene and hydroxyl bearing copolymers of butadiene and styrene.Iaddend., the mineral oil extended polyurethane when cured retaining the mineral oil within its structure, thereby preventing the oil from spewing and exuding from said cured composition.[., said composition possessing a gel-like consistency.].. 
     
     
       2. .[.Product according to.]. .Iadd.The cured, cross-linked, mineral oil extended polyurethane of .Iaddend.claim 1 in which the mineral oil employed is paraffin oil. 
     
     
       3. .[.Product according to.]. .Iadd.The cured, cross-linked, mineral oil extended polyurethane of .Iaddend.claim 1 in which the liquid coupling agent is 2,2,4-trimethyl .Badd..[.1,1,3-pentane diol.]..Baddend. .Iadd.1,3 pentanediol .Iaddend.diisobutyrate. 
     
     
       4. .[.Product according to.]. .Iadd.The cured, cross-linked, mineral oil extended polyurethane of .Iaddend.claim 1 in which the coupling agent is di-2 ethyl hexyl adipate. 
     
     
       5. .[.Product according to.]. .Iadd.The cured, cross-linked, mineral oil extended polyurethane of .Iaddend.claim 1 wherein said isocyanate terminated prepolymer is the reaction product of .Badd..[.3-isocyanatoemethyl.]..Baddend. .Iadd.3-isocyanato-methyl .Iaddend.3,3,5-trimethylcyclohexyl isocyanate and a liquid hydroxyl terminated homopolymer of butadiene. 
     
     
       6. A .Iadd.cured, cross-linked, .Iaddend.mineral oil extended polyurethane .[.system.]. comprising the reaction product of an isocyanate terminated prepolymer with a polyol .Iadd.selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof, .Iaddend.in the presence of a mineral oil and a liquid coupling agent for compatibilizing said mineral oil with said polyurethane, said .Iadd.mineral oil .Iaddend.extended polyurethane .[.system.]. containing from about 8 to .Iadd.about .Iaddend.45 parts of polyurethane .[.said urethane polymer.]., from about 25 to about 75 parts mineral oil and from about 10 to about 35 parts of .[.coupler.]. .Iadd.coupling agent.Iaddend., all parts expressed on a weight basis, said liquid coupling agent being miscible in all proportions with said mineral oil, said coupling agent selected from the group .[.consiting.]. .Iadd.consisting .Iaddend.of a ketone and an ester .[.of an organic compound selected from the group consisting of a diol and a diacid.]., said agent having a boiling temperature above 220° F., a solubility parameter between 7.0 and 9.5 and a hydrogen bonding index number in the range from .Badd..[.8.2 to 8.8.]..Baddend., .Iadd.6.0 to 12.0 and said agent being non-reactive with the prepolymer and the polyol, .Iaddend.said isocyanate terminated prepolymer .Iadd.being prepared by reacting a polyisocyanate selected from the group consisting of cycloaliphatic diisocyanate, aliphatic diisocyanate and aromatic diisocyanate with a polyol .Iaddend.selected from the group consisting of castor oil .[.and.]..Iadd., .Iaddend.polyether .Iadd.polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof, .Iaddend.wherein at least .[.one of said urethane forming reactants include a hydroxy bearing polybutadiene constituent.]. .Iadd.a portion of the polyol used in the preparation of the polyurethane is selected from the group consisting of hydroxyl bearing homopolymers of butadiene and hydroxyl bearing copolymers of butadiene and styrene.Iaddend., the mineral oil extended polyurethane when cured retaining the mineral oil within its structure, thereby preventing the oil from spewing and exuding from said cured composition.[., said composition possessing a gel-like consistency.].. 
     
     
       7. A .Iadd.cured, cross-linked, .Iaddend.mineral oil extended polyurethane .[.system.]. comprising the reaction product of an isocyanate terminated prepolymer with a polyol .Iadd.selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof, .Iaddend.in the presence of a mineral oil and a liquid coupling agent for compatabilizing said mineral oil with said polyurethane, said .Iadd.mineral oil extended .Iaddend.polyurethane .[.system.]. containing from about 20 to about 45 parts of .[.said urethane polymer.]. .Iadd.polyurethane.Iaddend., from about 25 to about 60 parts mineral oil and from about 25 to about 35 parts of .[.coupler.]. .Iadd.coupling agent.Iaddend., all parts expressed on a weight basis, said liquid coupling agent being miscible in all proportions with said mineral oil, said coupling agent .Iadd.being .Iaddend.selected from the group consisting of a ketone and an ester  .[.of an organic compound selected from the group consisting of a diol and diacid.]., said agent having a boiling temperature above 220° F., a solubility parameter between 7.0 and 9.5 and a hydrogen bonding index number in the range from .Badd..[.8.2 to 8.8.]., .Iadd.6.0 to 12.0 and said agent being non-reactive with the prepolymer and the polyol, .Iaddend.said isocyanate terminated prepolymer .Iadd.being prepared by reacting a polyisocyanate .Iaddend.selected from the group consisting of cycloaliphatic diisocyanate, aliphatic diisocyanate and aromatic diisocyanate.[.; said.]. .Iadd.with a .Iaddend.polyol selected from the group consisting of castor oil .[.and.]..Iadd., .Iaddend.polyether .Iadd.polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof, .Iaddend.wherein at least .[.one of said urethane forming reactants include a hydroxy bearing polybutadiene constituent.]. .Iadd.a portion of the polyol used in the preparation of the polyurethane is selected from the group consisting of hydroxyl bearing homopolymers of butadiene and hydroxyl bearing copolymers of butadiene and styrene.Iaddend., the mineral oil extended polyurethane when cured retaining the mineral oil within its structure, thereby preventing the oil from spewing and exuding from said cured composition.[., said composition being useful as a casting system.].. 
     
     
       8. .[.Composition according to.]. .Iadd.The cured, cross-linked, mineral oil extended polyurethane of .Iaddend.claim 1 which .[.preferably contains.]. .Iadd.comprises from .Iaddend.about 121/2 to about 15 parts by weight of .[.said urethane polymer.]. .Iadd.polyurethane, from .Iaddend.about 65 to about 70 parts .Iadd.by weight .Iaddend.of mineral oil and from about 15 to about 20 parts by weight of .[.coupler.]. .Iadd.coupling agent.Iaddend.. .Iadd. 
     
     
       9.  The cured, cross-linked, mineral oil extended polyurethane of claim 1 wherein said coupling agent has a hydrogen bonding index number in the range from 8.2 to 8.8. .Iaddend. .Iadd.10. The cured, cross-linked, mineral oil extended polyurethane of claim 6 wherein said coupling agent has a hydrogen bonding index number in the range from 8.2 to 8.8. .Iaddend. .Iadd.11. The cured, cross-linked, mineral oil extended polyurethane of claim 7 wherein said coupling agent has a hydrogen bonding index number in the range from 8.2 to 8.8. .Iaddend. .Iadd.12. A cured, cross-linked, mineral oil extended polyurethane which is non-spewing comprising: (a) from about 8 to about 45 parts, by weight, of polyurethane, said polyurethane being prepared by reacting (i) a polyisocyanate prepolymer prepared by the reaction of a polyisocyanate with a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene, and combinations thereof, with   (ii) a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene, and combinations thereof;     (b) from about 25 to about 75 parts, by weight, of mineral oil,   (c) from about 10 to about 35 parts, by weight, of coupling agent, said coupling agent being characterized by (i) being miscible in all proportions with said mineral oil,   (ii) having a solubility parameter between 7.0 and 9.5,   (iii) having a hydrogen bonding index number in the range of from 6.0 to 12.0, and   (iv) being non-reactive with the prepolymer and the polyol, and wherein the cured, cross-linked polyurethane is characterized by the presence of a polybutadiene moiety in the polyurethane structure.       
     
     
        .Iaddend. .Iadd.13.  The cured, cross-linked, mineral oil extended polyurethane of claim 12 wherein said coupling agent is selected from the group consisting of a ketone and an ester. .Iaddend. .Iadd.14. The cured, cross-linked, mineral oil extended polyurethane of claim 13 wherein said polyisocyanate is selected from the group consisting of cycloaliphatic diisocyanate, aliphatic diisocyanate and aromatic diisocyanate. .Iaddend. 
     
     
        .Iadd.15.  The cured, cross-linked, mineral oil extended polyurethane of claim 14 wherein said coupling agent is further characterized by having a boiling temperature above 220° F. .Iaddend. .Iadd.16. The cured, cross-linked, mineral oil extended polyurethane of claim 15 wherein said coupling agent has a hydrogen bonding index number in the range of from 8.2 to 8.8. .Iaddend. .Iadd.17. The cured, cross-linked, mineral oil extended polyurethane of claim 15 wherein one of the polyols of claim 12(a)(i) and (a)(ii) is castor oil. .Iaddend. .Iadd.18. The cured, cross-linked, mineral oil extended polyurethane of claim 15 wherein the polyols of claim 12(a)(i) and (a)(ii) are selected from the group consisting of hydroxyl bearing homopolymers of butadiene, hydroxyl bearing copolymers of butadiene and styrene, and combinations thereof. .Iaddend. .Iadd.19. The cured, cross-linked, mineral oil extended polyurethane of claim 15 wherein said mineral oil is a paraffin oil. .Iaddend. .Iadd.20. The cured, cross-linked, mineral oil extended polyurethane of claim 15 which comprises from about 8 to about 20 parts of polyurethane, from about 60 to about 75 parts of mineral oil and from about 10 to about 25 parts of coupling agent, all parts expressed on a weight basis. .Iaddend. 
     
     
        .Iadd.     The cured, cross-linked, mineral oil extended polyurethane of claim 15 which comprises from about 20 to about 45 parts of polyurethane, from about 25 to about 60 parts of mineral oil and from about 25 to about 35 parts of coupling agent, all parts expressed on a weight basis. .Iaddend. .Iadd.22. The cured, cross-linked, mineral oil extended polyurethane of claim 15 which comprises from about 121/2 to about 15 parts of polyurethane, from about 65 to about 70 parts of mineral oil and from about 15 to about 20 parts of coupling agent, all parts expressed on a weight basis. .Iaddend. .Iadd.23. A cured, cross-linked, mineral oil extended polyurethane which is non-spewing comprising from about 8 to about 45 parts of polyurethane, from about 25 to about 75 parts of mineral oil and from about 10 to about 35 parts of coupling agent, all parts expressed on a weight basis, wherein the cured, cross-linked polyurethane is characterized by the presence of a polybutadiene moiety in the polyurethane structure and is prepared from a mineral oil extended polyurethane precursor in admixture with the coupling agent, said coupling agent being characterized by: (a) possessing a solubility parameter between 7.0 and 9.5;   (b) having a hydrogen bonding index number in the range of 6.0 to 12.0;   (c) being miscible in all proportions with said mineral oil; and   (d) being non-reactive with said polyurethane precursor. .Iaddend.   
     
     
        .Iadd.     The cured, cross-linked, mineral oil extended polyurethane of claim 23 wherein the polybutadiene moiety is derived from at least one member of the group consisting of hydroxyl bearing homopolymers of butadiene and hydroxyl bearing copolymers of butadiene and styrene. .Iaddend. .Iadd.25. The cured, cross-linked, mineral oil extended polyurethane of claim 24 wherein said coupling agent is further characterized by having a boiling temperature above 220° F. .Iaddend.