Grease compatible mineral oil extended polyurethane

• US 4,231,986 A
• Filed: 04/06/1979
• Issued: 11/04/1980
• Est. Priority Date: 04/06/1979
• Status: Expired due to Term

• Current Assignee: CasChem, Inc.
• Original Assignee: NL Industries Incorporated (Valhi Holding Company)
• Inventors: Brauer, Melvin, Kroplinski, Thaddeus F.
• Primary Examiner(s): Jacobs, Lewis T.
• Application Number:
  US06/027,819
• Time in Patent Office: 578 Days
• Field of Search: 264/272, 260/33.6 UB, 260/33.6 AQ, 260/31.8 R, 260/32.8 N
• US Class Current: 264/272.11
• CPC Class Codes: C08K 5/01 Hydrocarbons C08K5/0091 takes precedence
• CPC Class Codes: C08K 5/07 Aldehydes; Ketones
• CPC Class Codes: C08K 5/10 Esters; Ether-esters
• CPC Class Codes: C08K 5/52 Phosphorus bound to oxygen only
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: H01B 7/285 by completely or partially filling interstices in the cable
• CPC Class Codes: Y02A 30/14 Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables

Abstract

A cured, cross-linked, mineral oil extended polyurethane which is non-spewing. The mineral oil extended polyurethane is further characterized by being grease compatible in that the tendency of the mineral oil to migrate is substantially reduced or eliminated. The mineral oil extended polyurethane is comprised of a defined polyurethane, mineral oil, and coupling agent. In other aspects, the present invention relates to a process for reclaiming or sealing an insulated electrical device and to an insulated electrical device which is formed by such process.

Claims

1. A process for sealing an insulated electrical device comprising the steps of introducing into said device a composition comprising mineral oil, polyurethane precursor and coupling agent,

(a) said polyurethane precursor comprising the reaction product of

(i) a polyisocyanate compound or a polyisocyanate prepolymer prepared by the reaction of a polyisocyanate compound with a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of dienes, hydroxyl bearing copolymers of dienes, and combinations thereof, wherein at least about 0.25 equivalents of the polyisocyanate compound per 1.0 equivalents of the polyisocyanate compound used is a liquid long chain aliphatic polyisocyanate, and

(ii) a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of dienes, hydroxyl bearing copolymers of dienes, and combinations thereof,

(b) said mineral oil being characterized by having from about 1.0 to about 30% aromatic carbon atoms, based on the total number of carbon atoms present in the mineral oil, and

(c) said coupling agent being characterized by

(i) being miscible in all proportions with said mineral oil,

(ii) having a total solubility parameter from about 7.0 to about 9.5,

(iii) having a hydrogen bonding index number from about 6.0 to about 12.0, and

(iv) being substantially non-reactive with said polyisocyanate prepolymer and said polyol,

reacting said polyol with said polyisocyanate in the presence of said mineral oil and said coupling agent to obtain a grease compatible, cured, cross-linked, mineral oil extended polyurethane which is non-spewing, and which is characterized by the presence of a polydiene moiety in the polyurethane structure, and which comprises from about 8 to about 45 parts of polyurethane, from about 20 to about 75 parts of mineral oil and from about 10 to about 47 parts of coupling agent, all parts expressed on a weight basis.

2. The process of claim 1 wherein the hydroxyl bearing homopolymers of dienes of claim 1, (a) (i) and (a) (ii) are hydroxyl bearing homopolymers of butadiene and wherein the hydroxyl bearing copolymers of dienes of claim 1, (a) (i) and (a) (ii) are hydroxyl bearing copolymers of butadiene.

3. The process of claim 1 wherein said liquid long chain aliphatic polyisocyanate contains from about 12 to about 50 carbon atoms in the carbon chain.

4. The process of claim 1 wherein the polyisocyanate compound used in the preparation of the polyurethane comprises about 0.25 equivalents of a mixture of polyisocyanate isomers derived from a 36 carbon dimer aliphatic acid and about 0.75 equivalents of polymethylene polyphenylisocyanate per 1.0 equivalents of polyisocyanate compound used.

5. The process of claim 1 wherein the grease compatible, cured, cross-linked, mineral oil extended polyurethane comprises from about 25 to about 45 parts of polyurethane, from about 20 to about 40 parts of mineral oil and from about 25 to about 47 parts of coupling agent, all parts expressed on a weight basis, wherein said coupling agent is further characterized by having a boiling temperature above about 220°

F. and being selected from the group consisting of a ketone and an ester, and wherein said mineral oil is characterized by having from about 5.0 to about 25% aromatic carbon atoms, based on the total number of carbon atoms present in the mineral oil.

6. The process of claim 1 wherein the polyisocyanate compound used in the preparation of the polyurethane is a mixture of polyisocyanate isomers derived from a 36 carbon dimer aliphatic acid.

13. The process of claim 1 wherein the coupling agent is characterized by

(i) being miscible in all proportions with said mineral oil,

(ii) having a total solubility parameter from about 8.2 to about 9.4,

(iii) having a polar and hydrogen bonding solubility parameter from about 3.2 to about 4.3,

(iv) having a non-polar solubility parameter from about 7.6 to about 8.4,

(v) having a hydrogen bonding index number from about 6.0 to about 12.0, and

(vi) being substantially non-reactive with said polyisocyanate prepolymer and said polyol.

7. A process for sealing an insulated electrical device comprising the steps of introducing into said device a composition comprising mineral oil, polyurethane precursor and coupling agent,

(a) said polyurethane precursor comprising the reaction product of

(i) a polyisocyanate compound or a polyisocyanate prepolymer prepared by the reaction of a polyisocyanate compound with a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of dienes, hydroxyl bearing copolymers of dienes, and combinations thereof, wherein at least 0.25 equivalents of the polyisocyanate compound per 1.0 equivalents of the polyisocyante compound used is a liquid long chain aliphatic polyisocyanate, and

(ii) a polyol selected from the group consisting of castor oil, polyether polyols, hydroxyl bearing homopolymers of dienes, hydroxyl bearing copolymers of dienes, and combinations thereof and

(b) said coupling agent being characterized by

(i) being miscible in all proportions with said mineral oil,

(ii) having a total solubility parameter from about 8.2 to about 9.4,

(iii) having a polar and hydrogen bonding solubility parameter from about 3.2 to about 4.3,

(iv) having a non-polar solubility parameter from about 7.6 to about 8.4,

(v) having a hydrogen bonding index number from about 6.0 to about 12.0, and

(vi) being substantially non-reactive with said polyisocyanate prepolymer and said polyol,

reacting said polyol with said polyisocyanate in the presence of said mineral oil and said coupling agent to obtain a grease compatible, cured, cross-linked, mineral oil extended polyurethane which is non-spewing, and which is characterized by the presence of a polydiene moiety in the polyurethane structure, and which comprises from about 8 to about 45 parts of polyurethane, from about 20 to about 75 parts of mineral oil, and from about 10 to about 47 parts of coupling agent, all parts expressed on a weight basis.

8. The process of claim 7 wherein said liquid long chain aliphatic polyisocyanate contains from about 12 to about 50 carbon atoms in the carbon chain.

9. The process of claim 7 wherein the grease compatible, cured cross-linked, mineral oil extended polyurethane comprises from about 25 to about 45 parts of polyurethane, from about 20 to about 40 parts of mineral oil and from about 25 to about 47 parts of coupling agent, all parts expressed on a weight basis, wherein said coupling agent is further characterized by having a boiling temperature above about 220°

F. and being selected from the group consisting of a ketone and an ester, and wherein said mineral oil is characterized by having from about 5.0 to about 25% aromatic carbon atoms, based on the total number of carbon atoms present in the mineral oil.

10. The process of claim 7 wherein the hydroxyl bearing homopolymers of dienes of claim 7 (a) (i) and (a) (ii) are hydroxyl bearing homopolymers of butadiene and wherein the hydroxyl bearing copolymers of dienes of claim 7, (a) (i) and (a) (ii) are hydroxyl bearing copolymers of butadiene.

11. The process of claim 7 wherein the polyisocyanate compound used in the preparation of the polyurethane comprises about 0.25 equivalents of a mixture of polyisocyanate isomers derived from a 36 carbon dimer aliphatic acid and about 0.75 equivalents of polymethylene polyphenylisocyanate per 1.0 equivalents of polyisocyanate compound used.

12. The process of claim 7 wherein the polyisocyanate compound used in the preparation of the polyurethane is a mixture of polyisocyanate isomers derived from a 36 carbon dimer aliphatic acid.