Encapsulant compositions for use in signal transmission devices

• US 4,985,475 A
• Filed: 11/25/1988
• Issued: 01/15/1991
• Est. Priority Date: 03/09/1987
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Haugen, Hartwick, Croft, Thomas S.
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Mulcahy, Peter D.
• Application Number:
  US07/274,337
• Time in Patent Office: 781 Days
• Field of Search: 523/173, 524/77, 524/322, 525/64, 525/74, 525/285
• US Class Current: 523/173
• CPC Class Codes: G02B 6/4401 Optical cables glass fibres with a protective coating G02B6/02395
• CPC Class Codes: H01B 3/26 asphalts; bitumens; pitches
• CPC Class Codes: H01B 3/44 vinyl resins; acrylic resins silicones H01B3/46
• CPC Class Codes: H01B 7/285 by completely or partially filling interstices in the cable

Abstract

The invention provides a grease compatible encapsulant composition capable of use with signal transmission devices, such as electrical or optical cable. The composition is the extended reaction product of an admixture of an anhydride functionalized compound, a crosslinking agent, and an oxirane containing material which provides improved hydrolytic stability to the encapsulant composition.

Claims

1. A grease compatible, hydrolytically stable dielectric encapsulant capable of being used to encapsulate a splice of a signal conducting device comprising:

an extended reaction product of an admixture of

(a) an effective amount of an anhydride functionalized compound having reactive anhydride sites;

(b) an effective amount of a crosslinking agent that reacts with the anhydride sites of said compound to form a cured cross-linked material; and

(c) an effective amount of an oxirane containing material to provide hydrolytic stability;

wherein said reaction product is extended with at least one plasticizer present in the range of between 5 and 95 percent by weight of the encapsulant and said at least one plasticizer is essentially inert with said reaction product and is substantially non-exuding therefrom; and

said encapsulant having a C-H adhesion value of at least 4.

2. The encapsulant of claim 1 wherein said oxirane containing material has at least one oxirane group.

3. The encapsulant of claim 2 wherein said admixture has a ratio of equivalents of anhydride functionalized compound to epoxy equivalent of between about 0.25 to about 1.5.

4. The encapsulant of claim 3 wherein said ratio is between about 0.25 to about 0.55.

5. The encapsulant of claim 2 wherein said oxirane containing material is selected from the group consisting of aliphatic alkyl, alkenyl, alkadiene, and cycloalkyl epoxies.

6. The encapsulant of claim 5 wherein said oxirane containing material is selected from the group consisting of aliphatic glycidyl ethers, aliphatic glycidyl esters, epoxidized dienes, epoxidized polyesters, epoxidized alpha olefins, epoxidized polyolefins, epoxidized natural rubber, epoxidized oils.

7. The encapsulant of claim 6 wherein said oxirane containing material is an epoxidized oil.

8. The encapsulant of claim 7 wherein said epoxidized oil is an epoxidized polyunsaturated vegetable oil.

9. The encapsulant of claim 2 wherein said oxirane containing material is selected from the group consisting of monoepoxy, diepoxy and polyepoxy compounds and combinations thereof.

10. The encapsulant of claim 1 wherein said oxirane containing material is present in an amount ranging between about 1.5 to about 50 percent by weight based on the total solids of said reaction product.

11. The encapsulant of claim 10 wherein said anhydride functionalized compound is present in an amount ranging between about 1 to about 90 percent by weight based on total solids of said reaction product and said crosslinking agent is present in an amount ranging between about 0.5 to about 80 percent by weight based on the total solids of said reaction product.

12. The encapsulant of claim 1 wherein said anhydride functionalized compound is present in an amount ranging from about 3 to 60 percent by weight, said crosslinking agent is present in an amount ranging from about 1 to 30 percent by weight and said oxirane containing material is present in an amount ranging from about 1.5 to about 20 percent by weight, each based on the total weight of the encapsulant.

13. The encapsulant of claim 11 further comprising a catalyst present in an amount between 0.1 and 5 percent by weight based on total solids of said reaction product.

14. The encapsulant of claim 1 wherein said encapsulant has a tensile strength of less than about 21.1N/cm² and between about 50 to 250 percent elongation.

15. The encapsulant of claim 1 having a total solubility parameter of between about 7.9 to about 9.5.

16. The encapsulant of claim 1 having a Polycarbonate Compatibility Value of at least 80.

17. A hydrolytically stable dielectric encapsulant capable of being used to encapsulate a signal transmission device comprising:

(1) an extended reaction product of an admixture of

(a) an effective amount of an anhydride functionalized compound having reactive anhydride sites;

(b) an effective amount of a polyol cross-linking agent that reacts with the anhydride sites of said compound to form a cured crosslinked material;

(c) an effective amount of an oxirane material sufficient to provide hydrolytic stability;

(d) an effective amount of a catalyst for the reaction between said anhydride functionalized composition, said polyol crosslinking agent and said oxirane material capable of catalyzing the reaction thereof in less than about 24 hours at 25°

C.; and

(2) at least one plasticizer present in the range of between 5 and 95 percent by weight of said encapsulant and being essentially inert with said reaction product and substantially non-exuding therefrom,

wherein said encapsulant has a C-H adhesion value of at least 4.