Sealant compositions and sealed electrical connectors

• US 5,360,350 A
• Filed: 05/05/1992
• Issued: 11/01/1994
• Est. Priority Date: 08/23/1991
• Status: Expired due to Term

• Current Assignee: The Whitaker Corporation (Meggitt PLC)
• Original Assignee: The Whitaker Corporation (Meggitt PLC)
• Inventors: Lynch, Thomas J., Mellinger, Ricky C., Koblitz, Francis F.
• Primary Examiner(s): Michl, Paul R.
• Assistant Examiner(s): MERRIAM, ANDREW EDWIN
• Application Number:
  US07/878,807
• Time in Patent Office: 910 Days
• Field of Search: 252/570, 252/575, 439/936, 439/276, 524/505, 524/507, 524/476, 525/89, 523/173
• US Class Current: 439/276
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/005 Modified block copolymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 modified
• CPC Class Codes: C09K 2200/0247 Silica
• CPC Class Codes: C09K 2200/0405 Hydrocarbons
• CPC Class Codes: C09K 2200/06 Macromolecular organic compounds, e.g. prepolymers
• CPC Class Codes: C09K 2200/0617 Polyalkenes
• CPC Class Codes: C09K 2200/062 Polyethylene
• CPC Class Codes: C09K 2200/0632 Polystyrenes
• CPC Class Codes: C09K 2200/0642 Copolymers containing at least three different monomers
• CPC Class Codes: C09K 3/10 Materials in mouldable or extrudable form for sealing or packing joints or covers filling pastes C09D5/34
• CPC Class Codes: H01B 7/282 Preventing penetration of fluid , e.g. water or humidity, into conductor or cable
• CPC Class Codes: H01B 7/285 by completely or partially filling interstices in the cable
• CPC Class Codes: H01B 7/292 using material resistant to heat
• CPC Class Codes: H01R 13/5216 characterised by the sealing material, e.g. gels or resins
• CPC Class Codes: H01R 4/2495 Insulation penetration combined with permanent deformation of the contact member, e.g. crimping
• CPC Class Codes: H01R 4/70 Insulation of connections end caps H01R4/22
• CPC Class Codes: Y10S 439/936 : Potting material or coating, e.g. grease, insulative coating, sealant or, adhesive
• CPC Class Codes: Y10S 525/903 : Interpenetrating network

Abstract

Disclosed are sealant compositions having excellent slump and spew resistance, even at relatively high operating temperatures for electrical connectors. The sealants, which are flowable at such elevated temperatures, comprise two essential components: elastomeric thermoplastic polymer, preferably an organic polymer composite comprising diblock and triblock copolymers, and extender for the polymer. The extender may comprise a primary and a secondary extender, such as polybutene oil and mineral oil, respectively.

Claims

1. A moisture and temperature resistant electrical connector for sealingly connecting transmission means comprising:

(a) a connector body comprising a substantially closed container having access means for allowing entry of said transmission means into said connector body and a terminal means for accepting and electrically connecting with said transmission means; and

(b) a sealant composition substantially filling said container and disposed along or adjacent to said terminal means, said sealant composition comprising an elastomeric thermoplastic polymer composite and an extender for said polymer composite, said extender comprising a major proportion by weight of said composition and said polymer composite comprising a minor proportion by weight of said composition,

wherein said polymer composite includes a mixture of

(i) a triblock copolymer and

(ii) a diblock copolymer, the weight ratio of said triblock copolymer to said diblock copolymer being in the range of about 1;

20 to about 1;

5; and

wherein said extender includes

(i) a primary extender for said polymer, said primary extender being selected from the group consisting essentially of C₁ -C₄ polyolefins and

(ii) a secondary extender for said polymer, said secondary extender being selected from the group consisting essentially of mineral oil the weight ratio of said primary extender to said secondary extender being in the range of about 50;

50.

2. The connector of claim 1 in which the weight ratio of said extender to said polymer is in the range of about 9.5:

0.5 to about 85;

15.

3. The connector of claim 2 wherein said weight ratio of said extender to said polymer is about 93:

7 to about 8;

2.

4. The connector of claim 1 wherein said weight ratio of said triblock copolymer to said diblock copolymer is in the range of about 1:

20 to about 1;

10.

5. The connector of claim 1 wherein said diblock copolymer comprises a block of non-elastomeric polymer connected to a block of elastomeric polymer, said non-elastomeric polymer block being selected from the group consisting of poly(alkenyl arenes), polyurethanes and combinations of these, and said elastomeric polymer block being selected from the group consisting of non-aromatic polyolefins, polyesters, polyethers and combinations of these.

6. The connector of claim 5 wherein said non-elastomeric polymer block comprises a poly(alkenyl arene) and said elastomeric polymer block comprises a non-aromatic polyolefin.

7. The connector of claim 6 wherein said non-elastomeric polymer block comprises polystyrene and said elastomeric polymer block comprises a C1-C6 non-aromatic polyolefin.

8. The connector of claim 7 wherein said non-elastomeric polymer block comprises polystyrene and said elastomeric polymer block comprises poly(ethylene-propylene).

9. The connector of claim 1 wherein said triblock copolymer comprises a block of non-elastomeric polymer connected to a block of elastomeric polymer, said block of elastomeric polymer being connected to another block of non-elastomeric polymer, said non-elastomeric polymer block being selected from the group consisting of poly(alkenyl arenes), polyurethanes and combinations of these, and said elastomeric polymer block being selected from the group consisting of non-aromatic polyolefins, polyesters, polyethers and combinations of these.

10. The connector of claim 9 wherein said non-elastomeric block comprises a poly(alkenyl arene) and said elastomeric block comprises a non-aromatic polyolefin.

11. The connector of claim 10 wherein said non-elastomeric block comprises polystyrene and said elastomeric block comprises a C₁ -C₆ non-aromatic polyolefin.

12. The connector of claim 11 wherein said elastomeric polymer block comprises poly(ethylene-butylene).

13. The connector of claim 1 wherein said weight ratio of said primary extender to said secondary extender is in the range of about 40:

60 to about 60;

40.

14. The connector of claim 1 wherein said primary extender comprises a C₄ polyolefin.

15. The connector of claim 14 wherein said primary extender is selected from the group consisting of polybutene, polybutadiene and polyisobutene.

16. The connector of claim 1 wherein said mineral oil compresses white oil.

17. The connector of claim 1 wherein said composition further comprises fumed silica.

18. The connector of claim 17 wherein said composition further comprises less than about 8 percent by weight of fumed silica.

19. The connector of claim 18 wherein said composition comprises from about 0.1 to about 6.0 percent by weight of fumed silica.

20. The connector of claim 19 wherein said fumed silica is selected from the group consisting of hydrophobic surface treated amorphous silica, hydrophilic amorphous silica and mixtures of these.

21. The connector of claim 1 wherein said composition further comprises a crosslinked polymer.

22. The connector of claim 21 wherein said crosslinked polymer comprises an inorganic crosslinked polymer.

23. The connector of claim 22 wherein said inorganic crosslinked polymer comprises a crosslinked silicon-based polymer.

24. The connector of claim 23 wherein said crosslinked silicon-based polymer is selected from the group consisting of polysilanes, polysiloxanes, polysilalkylenes, and polysilarylenes.

25. The connector of claim 24 wherein said crosslinked silicon-based polymer comprises a polysiloxane.

26. The connector of claim 21 wherein said inorganic crosslinked polymer comprises less than about 35 percent by weight of said composition.

27. The connector of claim 26 wherein said inorganic crosslinked polymer comprises less than about 25 percent by weight of said composition.

28. The connector of claim 21 wherein said organic elastomeric thermoplastic polymer and said inorganic crosslinked polymer together comprise less than about 20 percent by weight of the composition.

29. The connector of claim 28 wherein said organic elastomeric thermoplastic polymer and said inorganic crosslinked polymer together comprise less than about 15 percent by weight of the composition.

30. The connector of claim 1 wherein said composition comprises:

about 45 parts by weight of mineral oil,

about 45 parts by weight of polyisobutene,

about 0.75 part by weight of poly(styrene-ethylene-butylene-styrene) triblock copolymer,

about 7.5 parts by weight of poly(styrene-ethylene-propylene) diblock copolymer,

about 0.5 part by weight of antioxidant/thermal stabilizer,

about 0.05 part by weight of corrosion inhibitor,

about 0.015 part by weight of fungicide, and

about 0.05 part by weight of surfactant.

31. The connector of claim 1 wherein said triblock copolymer consists essentially of poly(alkenyl arene) non-elastomeric polymer block material and non-aromatic polyolefin elastomeric polymer block material, and

said diblock copolymer consists essentially of poly(alkenyl arene) non-elastomeric polymer block and non-aromatic polyolefin elastomeric polymer block material.

32. The connector of claim 31 wherein said non-elastomeric polymer block material of said triblock copolymer consists essentially of polystyrene,

said elastomeric block material of said triblock copolymer consists essentially of C₁ -C₆ non-aromatic polyolefin,

said non-elastomeric polymer block material of said diblock copolymer consists essentially of polystyrene,

said elastomeric block material of said diblock copolymer consists essentially of C₁ -C₆ non-aromatic polyolefin,

said primary extender consists essentially of a C₄ polyolefin, and

said secondary extender consists essentially of a mineral oil.

33. The connector of claim 32 wherein said elastomeric block material of said triblock copolymer consists essentially of poly(ethylene-butylene),

said elastomeric block material of said diblock copolymer consists essentially of poly(ethylene-propylene), and

said primary extender consists essentially of a polyisobutene oil.

34. The connector of claim 31 wherein said weight ratio of said triblock copolymer to said diblock copolymer is about 1:

10.

38. The method of claim 25 wherein said weight ratio of said triblock copolymer to said diblock copolymer is in the range of about 1:

20 to about 1;

10.

43. The method of claim 2 wherein said mineral oil comprises white oil.

35. A method of manufacturing a moisture and temperature resistant electrical connector for sealingly connecting transmission means comprising:

(a) a connector body comprising a substantially closed container having access means for allowing entry of said transmission means into said connector body and a terminal means for accepting and electrically connecting with said transmission means; and

(b) a sealant composition substantially filling said container and disposed along or adjacent to said terminal means, said sealant composition comprising an elastomeric thermoplastic polymer composite and an extender for said polymer composite, said extender comprising a major proportion by weight of said composition and said polymer composite comprising a minor proportion by weight of said composition,

wherein said polymer composite includes a mixture of

(i) a triblock copolymer and

(ii) a diblock copolymer, the weight ratio of said triblock copolymer to said diblock copolymer being in the range of about 1;

20 to about 1;

5; and

wherein said extender includes

(i) a primary extender for said polymers, said primary extender selected from the group consisting of C₁ -C₄ polyolefins and

(ii) a secondary extender for said polymer, said secondary extender being selected from the group consisting essentially of mineral oil, the weight ratio of said primary extender to said secondary extender being in the range of about 50;

50.

36. The method of claim 35 in which the weight ratio of said extender to said polymer is in the range of about 9.5:

0.5 to about 85;

15.

37. The method of claim 36 wherein said weight ratio said extender to said polymer is about 93:

7 to about 8;

2.

39. The method of claim 35 wherein said weight ratio of said primary extender to said secondary extender is in the range of about 40:

60 to about 60;

40.

40. The method of claim 35 wherein said triblock copolymer comprises poly(alkenyl arene) non-elastic polymer block material and non-aromatic polyolefin elastomeric polymer block material, and said diblock copolymer consists essentially of polymer(alkenyl arene) non-elastic polymer block material and non-aromatic polyolefin elastomeric polymer block material.

41. The method of claim 40 wherein said elastomeric polymer block material of said triblock copolymer consists essentially of poly(ethylene-butylene), said elastomeric polymer block material of said diblock copolymer consists essentially of poly(ethylene-propylene) and said primary extender consists essentially of polyisobutene oil.

42. The method of claim 41 wherein said weight ratio of said triblock copolymer to said diblock copolymer is about 1:

10.