WATER REACTIVE SEALANT COMPOSITION

Abstract: Water reactive sealant composition comprising a polyfunctional carboxylic acid or anhydride, an inorganic basic oxide, a hydrophilic additive, and a thickening agent. Composition can be effectively used as an encapsulant or sealant, exhibits electrically insulating properties, and is reactive upon contact with moisture to prevent further ingress of water.

Description: ATER REACTIVE SEALANT COMPOSITION Technical Field The invention relates to a composition which can be effectively used as an encapsulant/sealant, has electrically insulating properties, and is reactive upon contact with moisture to prevent further ingress of water therein. More specifically, the composition comprises a polyfunctional carboxylic acid/anhydride, an inorganic basic oxide, a hydrophilic additive, and a thickening agent. Background Art Modern sealants are comprised of one-part and two-part compositions which, in the uncured state, are either pourable or putty-like. When cured> such materials are transformed into three-dimensional structures which in theory form a barrier against moisture, gases and various. contaminates. Two classes of sealants are activated by moisture: moisture-cured sealants and moisture-activated catalyst cured sealants. The majority of moisture-cured sealants are one-part urethanes and one-part silicones. Urethane sealants contain unreacted isocyanate groups which react with moisture to form a continuous three-dimensional network through urea linkages (see, e.g., U.S. Patent No. 4,539,345) . One-part silicones contain hydrolyzable groups which react with moisture to yield silanol groups, form Si-O-Si bonds and crosslink (see, e. g. , U.S. Patent No. 4,652,624). Polysulfides and polymercaptans are examples of moisture-activated catalyst cured sealants (such as those disclosed in U.S. Patent Nos. 3,872,059 and 4,830,688). Atmospheric moisture ionizes the heavy metal catalyst which then catalyzes the curing reaction. U.S. Patent No. 4,116,886 represents an example of moisture-curable epoxies, which are not as common in sealant usage as those above. All of these systems have inherent problems to their use. It is well known that isocyanate compounds can induce allergic reactions in certain persons. Silicones are the highest in price among marketed sealants; thio-functional sealants have an obnoxious odor. Hydrocarbon greases have existed for a long time and are still used as insulating materials. Great Britain Patent Nos. 526,510; 530,374; 1,039,166; and 1,592,165 and U.S. Patent No. 3,314,886 all describe the use of insulating oils containing additives therein, typically based on the reaction of a carboxylic acid and an inorganic base dispersed in the insulating oil, primarily a hydrocarbon oil. The ability to insulate is attributed to the hydrocarbon oil. The additives typically include a higher fatty acid and a base, capable of reacting with the acid, which forms a water-insoluble, oleophilic, metal soap. The compositions may contain polycarboxylic acid as gelling agents, polymers, antioxidants and dispersants. All examples contain a liquid vehicle, such as a hydrocarbon oil, which is taught to provide the insulative characteristics to the composition. The acid/base reaction occurs upon mixing, in most cases at elevated temperatures. The practice of using an insulating oil is also seen in the manufacture of reenterable encapsulants. Various polyurethane based gels are disclosed in U.S. Patent Nos. 4,102,716; 4,533,598; 4,375,521; 4,355,130; 4,281,210; 4,596,743; 4,168,258; 4,329,442; 4,231,9.86; 4,171,998; 4,029,626 and 4,008,197. The third class is the water-reactive grease composition, such as that disclosed in U.S. Patent No. 4,639,483. This composition consists of an insulating oil, a carboxylic acid having 18 to 200 carbons, a basic oxide selected from calcium oxide or zinc oxide, optionally an elastomer, soluble in the composition, and optionally a hydrophilic additive. This composition remains in a soft, reenterable state. The mixture of insulating oil, carboxylic acid and basic oxide has the consistency of grease. Upon the ingress of water, the composition cures to the consistency of hard rubber or plaster of paris which stops water from further penetration. This reference teaches the surprising feature that certain carboxylic acids may be combined with certain inorganic basic oxides (i.e., CaO and ZnO) in oils to form a paste in which no reaction between the acid and base will take place, and which is stable at ambient conditions. However, upon the addition of water the acid and base react to form a hard solid. In contrast with the foregoing, the present invention consists of a polyfunctional carboxylic acid/anhydride, an inorganic basic oxide, a hydrophilic additive, and a thickening agent. Surprisingly, a moisture-curable insulative composition is provided which is capable of consuming water, reacting and forming a barrier from further penetration of water or water vapor. Also, surprisingly, the very additives taught to act as modifiers to an insulating oil have themselves been found to provide an excellent insulating material, superior in its ability to prevent the ingress of water. Detailed Description of Illustrative Embodiments As discussed above, the present invention consists of a mixture of a liquid polyfunctional carboxylic acid or anhydride together with an inorganic basic oxide. These two components are inert toward each other and when mixed with a hydrophilic additive and a suspending or thickening agent, a composition having the consistency of grease is formed. When water comes in contact with the basic oxide component, hydrolysis occurs and the corresponding hydroxide is formed. The hydroxide then enters into a second reaction with the organic acid to produce a barrier layer of various thickness depending on the specific components. Surprisingly, the remaining material remains reenterable and has excellent insulating properties. Prior art sealants are either soft, allowing water to penetrate, are hard and not reenterable, or turn hard on water contact and become difficult to reenter. The acidic component has been determined to be a liquid polyfunctional carboxylic acid or anhydride. Any acidic material can be utilized as long as it does not react with the basic oxide component. In fact, numerous saturated, unsaturated or aromatic di-, tri-, and polycarboxylic acids or anhydrides are available for use. Commercial examples of suitable acidic materials include the Empol™ series from the Quantum Chemical Company; the Hystrene™ series available from Witco Chemical; the Ricon™ series available from the Colorado Chemical Specialties, Inc. ; the Versadyme™ series available from Henkel/Emery Industries; the Unidyme™ series available from Union Camp; the LIR™ and NISSO™ series available from Kennedy and Klim, Inc.; and the Hycar™ series available from B. F. Goodrich. The amount of acid may vary from about 35 to about 70 parts by weight of the total composition, with from about 45 to about 60 parts by weight being preferred. Mono-acids within dimer acids have been found to reduce the stability of the composition during heat aging; i.e., the composition may become a solid at elevated temperatures without the presence of water. It has been discovered that increasing the basic oxide content allows for an increase in stability such that compositions containing high mono-acid contents such as Empol™ 1003 which has a mono-acid content of about 20 weight percent, do not react in the absence of water. Preferred acidic materials are dimer acids having mono-acid contents of less than about 2 weight percent. Representative basic oxides are those of copper (I) , barium, calcium, magnesium, zinc and strontium. As discussed above, the oxide must be stable with the acid material and be hydrolyzable to form a hydroxide reactive with the acid. The preferred basic oxide is calcium oxide. The basic oxide may vary from about 15 to about 50 parts by weight, and preferably about 25 to about 35 parts by weight, based on the total composition. The hydrophilic additive may be a hydrophilic clay, such as BEN-A-GEL™ available from NL Industries or a hydrophilic polymer, such as polyvinyl pyrrolidone or polyvinyl alcohol. There are various grades of hydrophilicity of such additives, i.e., they may not function at the same rate or efficiency but are still useful herein. Other commercial examples of hydrophilic additives include: Aridall™ 1125, the potassium salt of polyacrylic acid, from Chemdal Corp.; Elvanol™ 71-30, a 99% to 99.8% hydrolyzed polyvinyl alcohol from DuPont; Vinol™ 540S, an 87% to 90% hydrolyzed polyvinyl alcohol from Air Products Company; and the sodium salts of various high molecular weight organic acids available as Waterlock™ from the Grain Processing Corp. Preferably, the hydrophilic additive is dry or has been dried, e.g., oven dried, before use in compositions of the invention as adsorbed water therein may tend to reduce the shelf life or stability of the resultant composition. The Elvanol™ 71-30 has been found to produce a hard cured composition at the water interface, while the Vinol™ material, being less hydrolyzed, yields a softer cured composition at the water interface. The hydrophilic additive may vary from about 1 to about 25 parts by weight based on the total composition, with the preferred concentration being from about 8 to about 20 parts by weight. A preferred hydrophilic additive is polyvinyl alcohol. The suspending agent must be capable of suspending the inorganic oxide. The agent may vary from about 0.1 to about 10 parts by weight, with the preferred being from about 1 to about 4 parts by weight, again based on the total composition. There are many suspending agents which are sufficient, examples thereof being Cab-O-Sil™ M-5, an amorphous fumed silica from the Cabot Corp, (our preferred agent) ; aluminum octoate; Alumagel™ from the Witco Chemical Corp.; Infusorial Earth™, a diatomateous earth available from Fisher Scientific Company; metal soaps such as the calcium salt of lauric acid commercially available from Pfaltz & Bauer, Inc.; magnesium or aluminum salts of stearic acid available from Fisher Scientific Co.; powdered polyvinyl chloride commercially available from B. F. Goodrich Co. ; and glass-walled hollow microspheres available from Minnesota Mining and Manufacturing (3M). Other conventional additives such as fillers, antioxidants and fungicides may be added as desired. The compositions of the present invention find utility in all applications where it is desired to seal or block water within electronic components, copper or fiber optic cable, and power cable. They are particularly useful as reenterable sealants for the protection of telephone cable or power cable splices where good insulating properties are needed along with a means to inhibit the ingress of water. Other useful applications include: telephone pedestal sealant, buried service wire closure sealant, cable filler, water blocks, manhole restoration sealant, duct sealant, connector filler, module splice protection, closure system component (as either a hermetic cable seal or air block between closure walls) , mastic, and firebarrier material. The present invention is also directed to a splice assembly, comprising the moisture reactive material (sometimes referred to as the sealant) , at least two conductors spliced together, and optionally, a closure (sometimes also referred to as a splice closure or connector) . Prior to exposure to moisture, the inventive composition is sufficiently soft to flow around and into the interstices of the splice assembly and establish intimate contact with the splice. The moisture-activatable material remains soft until such time as it is contacted by moisture, such as through contact with liquid water or water vapor. While the sealant remains soft, the splice closure is readily reenterable. Upon contact with moisture, the sealant begins to react. When in contact with surface water, the reaction is limited to a "skinning" on the surface, while remaining unreacted beneath the skin. When water is mixed in with the sealant, the sealant consumes the moisture. Consequently, the sealant can actually improve (and even restore) service which has been impaired (or interrupted) through entry of water into the splice area. The invention is more specifically delineated by the following non-limiting examples. In all instances, the compositions were prepared by mixing the indicated components under ambient conditions using a Hobart N-50 dough mixer, commercially available from Hobart Manufacturing. Unless otherwise indicated, all amounts are expressed in parts by weight. The samples were then examined to determine the insulating properties thereof by insertion of a probe having two conductors spaced about 0.5 inch apart (1.25 cm) into the material being tested, with the assembly, i.e., the probe and material, being immersed under 30.5 cm of water and aged at 60°C. A second test, one to determine the effect of temperature cycling on the composition, was configured in the same manner as the water test above, with the difference being that a temperature cycle from -40°C to 60°C, at three cycles per day, was used. The samples were considered to have failed if the insulation resistance thereof fell to below 100 mega ohms (1.0 E 8 ohms). Penetrometer readings were undertaken according to ASTM D-217, using a full cone. Examples Example 1 2 3 4 5 6 Formulation Versadyme™ 288 55.82 64.75 49.55 58.81 49.55 58.81 Calcium Oxide 27.09 21.62 35.28 28.81 24.04 19.63 Elvanol™ 71-30 15.82 12.63 14.04 11.47 25.28 20.64 Cab-O-Sil™ M-5 1.27 1.01 1.12 0.92 1.12 0.92 Material Characterization Specific Gravity (gm/cc) 1. 155 1. 171 1. 197 1. 224 1. 204 1. 178 Full Cone Penetration (1/10 mm) 398 423 392 419 350 431 Aging in Water @ 60°C (Days to Failure) 57+ 57+ 57+ 57+ 57+ 57+ Temperature Cycling (Cycles to Failure) 102+ 102+ 102+ 102+ 102+ 102+ + Denotes the test was terminated without failure. Example 7 8 9 10 11 12 Formulation Versadyme™ 288 44.55 53.87 54.44 63.47 48.86 57.75 Calcium Oxide 31.72 26.39 26.42 21.19 34.51 28.29 Elvanol™ 71-30 22.73 18.91 15.43 12.38 13.74 11.26 Cab-O-Sil™ M-5 1.01 0.84 3.70 2.97 3.30 2.70 Example 7 8 9 10 11 12 Material Characterization Specific Gravity (gm/cc) 1. 287 1. 190 1. 221 1. 216 1. 220 1. 278 Full Cone Penetration (1/10 mm) 395 377 302 283 285 367 Aging in Water § 60°C (Days to Failure) 57+ 57+ 57+ 57+ 57+ 57+ Temperature Cycling (Cycles to Failure) 102+ 102+ 102+ 90 102+ 102+ + Denotes the test was terminated without failure. Example 13 14 15 16 17 18 Formulation Versadyme™ 288 48.46 57.75 43.66 52.98 46.54 59.79 Calcium Oxide 23.52 19.28 31.09 25.95 30.75 23.13 Elvanol™ 71-30 24.73 20.27 22.28 18.59 20.38 15.33 Cab-O-Sil™ M-5 3.30 2.70 2.97 2.48 2.33 1.75 Material Characterization Specific Gravity (gm/cc) 1. 281 1. 264 1. 218 1. 213 1. 230 1. 155 Full Cone Penetration (1/10 mm) 231 331 227 349 355 381 Aging in Water § 60°C (Days to Failure) 57+ 57+ 57+ 57+ 57+ 57+ Temperature Cycling (Cycles to Failure) 102+ 12++ 102+ 102+ 102+ 102+ + Denotes the test was terminated without failure. ++ Denotes the test was terminated because of testing assembly failure. Example 19 20 21 22 23 24 Formulation Versadyme™ 288 58.22 50.53 58.22 50.53 54.87 53.35 Calcium Oxide 20.80 31.26 28.41 24.66 26.78 26.03 Elvanol™ 71-30 18.83 16.34 11.22 22.95 17.75 17.26 Cab-O-Sil™ M-5 2.15 1.87 2.15 1.87 0.60 3.36 Material Characterization Specific Gravity (gm/cc) 1.146 1.215 1.274 1.175 1.199 1.193 Full Cone Penetration (1/10 mm) 364 329 370 318 427 299 Aging in Water @ 60°C (Days to Failure) 57+ 57+ 57+ 57+ 57+ 57+ Temperature Cycling (Cycles to Failure) 18++ 102+ 102+ 102+ 102+ 102+ + Denotes the test was terminated without failure. ++ Denotes the test was terminated because of testing assembly failure. Example 25 Formulation Versadyme™ 288 54.10 Calcium Oxide 26.40 Elvanol™ 71-30 17.50 Cab-O-Sil™ M-5 2.00 Example 25 Material Characterization Specific Gravity (gm/cc) 1.184 Full Cone Penetration (1/10 mm) 318 Aging in Water @ 60°C (Days to Failure) 57+ Temperature Cycling (Cycles to Failure) 102+ + Denotes the test was terminated without failure. Example 26 27 28 29 30 31 Acidic Materials Hystrene™ 5460 54.1 Empol™ 003 54.1 Empol™ 1040 54.1 Empol™ 1041 54.1 Empol™ 1052 54.1 Versadyme™ 204 54.1 Hycar™ 2000X-162 CTB Ricon™ 156 C Ricon™ 157 C LIR™ 403 LIR™ 410 Nisso™ PB C-1000 Ricon™ 131/MA Ricon™ 130/13MA Ricon™ 181/10MA Basic Oxide Calcium Oxide 26.4 26.4 26.4 26.4 26.4 26.4 Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 2.0 2.0 2.0 2.0 Hydrophilic Additive Elvanol™ 71-30 17.5 17.5 17.5 17.5 17.5 17.5 Example 26 27 28 29 30 31 Material Characterization Specific Gravity (gm/cc) 1.204 1.174 1.204 1.162 1.273 1.207 Full Cone Penetration (1/10 mm) 267 252 322 358 381 315 Aging in Water @ 60°C (Days to Failure) 2 31+ 31+ 31+ 31+ 2 Temperature Cycling (Cycles to Failure) 0 81+ 81+ 81+ 81+ 0 + denotes the test was terminated without failure. NT denotes the material was not tested. Example 32 33 34 35 36 37 Acidic Materials 54.1 54.1 54.1 54.1 54.1 Calcium Oxide 26.4 26.4 26.4 26.4 26.4 26.4 Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 2.0 2.0 2.0 2.0 Hydrophilic Additive Elvanol™ 71-30 17.5 17.5 17.5 17.5 17.5 17.5 Example 32 33 34 35 36 37 Material Characterization Specific Gravity (gm/cc) 1.162 1.207 1.183 1.159 1.133 Full Cone Penetration (1/10 mm) 354 178 278 238 253 6 Aging in Water @ 60°C (Days to Failure) 31+ 31+ 31+ 31+ 31+ NT Temperature Cycling (Cycles to Failure) 81+ 81+ 81+ 81+ 81+ NT + denotes the test was terminated without failure. NT denotes the material was not tested. Example 38 39 40 Acidic Materials Hystrene™ 5460 Empol™ 1003 Empol™ 1040 Empol™ 1041 Empol™ 1052 Versadyme™ 204 Hycar™ 2000X-162 CTB Ricon™156 C Ricon™ 157 C LIR™ 403 LIR™ 410 Nisso™ PB C-1000 Ricon™ 131/MA 54.1 Ricon™ 130/13MA 54.1 Ricon™ 181/10MA 54.1 Basic Oxide Calcium Oxide 26.4 26.4 26.4 Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 2.0 Hydrophilic Additive Elvanol™71-30 17.5 17.5 17.5 Example 38 39 40 Material Characterization Specific Gravity (gm/cc) 1. 181 1. 141 1. 138 Full Cone Penetration (1/10 mm) 305 435 311 Aging in Water @ 60°C (Days to Failure) 31+ 31+ 31+ Temperature Cycling (Cycles to Failure) 75+ 75+ 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. Example 41 42 43 44 45 46 Basic Oxide Zinc Oxide 26.4 26.4 26.4 26.4 26.4 Magnesium Oxide 26.4 Barium Oxide Copper (I) Oxide Acidic Material Versadyme™288 54.1 51.1 54.1 Hycar™ 2000X-162 CTB 54.1 51.1 Ricon™131/MA 54.1 Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 2.0 2.0 Alumagel™ 5.0 5.0 Hydrophilic Additive Elvanol™71-30 17.5 17.5 17.5 17.5 17.5 17.5 Example 41 42 43 44 45 46 Material Characterization Specific Gravity (gm/cc) 1. 270 1. 156 1. 285 1. 183 1. 246 1. 216 Full Cone Penetration (1/10 mm) 267 352 87 110 302 358 Aging in Water 6 60°C (Days to Failure) 31 31+ 31+ 3 57+ 57+ Temperature Cycling (Cycles to Failure) 75+ 75+ 75+ 75+ 75+ 12 + denotes the test was terminated without failure. NT denotes the material was not tested. Example 47 48 49 50 51 52 Basic Oxide Zinc Oxide Magnesium Oxide 26.4 26.4 26.4 26.4 Barium Oxide 26.4 26.4 Copper (I) Oxide Acidic Material Versadyme™288 51.1 54.1 51.1 Hycar™ 2000X-162 CTB 54.1 51.1 Ricon™131/MA 54.1 Suspending Agents Cab-0-Sil™M-5 2.0 2.0 2.0 Alumagel™ 5.0 5.0 5.0 Hydrophilic Additive Elvanol™71-30 17.5 17.5 17.5 17.5 17.5 17.5 Example 47 48 49 50 51 52 Material Characterization Specific Gravity (gm/cc) 1.141 NT NT 1.318 1.232 1.198 Full Cone Penetration (1/10 mm) 445 4 12 323 388 208 Aging in Water § 60°C (Days to Failure) 31+ NT NT 57+ 31+ 13 Temperature Cycling (Cycles to Failure) 48 NT NT 75+ 75+ 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. Example 53 54 55 56 57 58 Basic Oxide Zinc Oxide Magnesium Oxide Barium Oxide 26.4 26.4 26.4 Copper (I) Oxide 26.4 26.4 26.4 Acidic Material Versadyme™ 288 54.1 51.1 Hycar™ 2000X-162 CTB 54.1 51.1 54.1 Ricon™131/MA 54.1 Suspending Agents Cab-0-Sil™M-5 2.0 2.0 2.0 2.0 Alumagel" 5.0 5.0 Hydrophilic Additive Elvanol™71-30 17.5 17.5 17.5 17.5 17.5 17.5 Example 53 54 55 56 57 58 Material Characterization Specific Gravity (gm/CC) 1.204 1.159 1.183 1.290 1.222 1.149 Full Cone Penetration (1/10 mm) 295 265 365 362 381 110 Aging in Water § 60°C (Days to Failure) 31+ 6 31+ 31+ 13 57+ Temperature Cycling (Cycles to Failure) 75+ 75 75+ 75+ 75+ 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. Example 59 60 Basic Oxide Zinc Oxide Magnesium Oxide Barium Oxide Copper (I) Oxide 26.4 26.4 Acidic Material Versadyme™288 Hycar™ 2000X-162 CTB 51.1 Ricon™131/MA 54.1 Suspending Agents Cab-0-Sil™M-5 2.0 Alumagel™ 5.0 Hydrophilic Additive Elvanol™71-30 17.5 17.5 Example 59 60 Material Characterization Specific Gravity (gm/cc) 1.262 1.16 Full Cone Penetration (1/10 mm) . 140 313 Aging in Water § 60°C (Days to Failure) 3 31+ Temperature Cycling (Cycles to Failure) 27 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. Example 61 62 63 64 65 66 Hydrophilic Additive Elvanol™ 71-30 17.5 17.5 17.5 Vinol™ 540S 17.5 17.5 17.5 PVP™ K-90 Waterlock™ A-200 Waterlock™ G-400 Aridall™ 1125 Basic Oxide Calcium Oxide 26.4 26.4 26.4 26.4 26.4 26.4 Acidic Material Versadyme™ 288 54.1 54.1 Hycar™ 2000X-162 CTB 54.1 54.1 Ricon™ 131/MA 54.1 54.1 Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 2.0 2.0 2.0 2.0 Example 61 62 63 64 65 66 Material Characterization Specific Gravity (gm/cc) 1.168 1.138 1.129 1.186 1.123 1.138 Full Cone Penetration (1/10 mm) 291 208 377 363 390 456 Aging in Water § 60°C (Days to Failure) 57+ 31+ 57+ 57+ 57+ 57+ Temperature Cycling (Cycles to Failure) 75+ 75+ 75+ 75+ 75+ 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. Example 67 68 69 70 71 72 Hydrophilic Additive Elvanol™ 71-30 Vinol™ 54OS PVP™ K-90 17.5 17.5 17.5 Waterlock™ A-200 17.5 17.5 17.5 Waterlock™ G-400 Aridall™ 1125 Basic Oxide Calcium Oxide 26.4 26.4 26.4 26.4 26.4 26.4 Acidic Material Versadyme™288 54.1 54.1 Hycar™ 2000X-162 CTB 54.1 54.1 Ricon™ 131/MA 54.1 54.1 Suspending Agents Cab-0-Sil™M-5 2.0 2.0 2.0 2.0 2.0 2.0 Example 67 68 69 70 71 72 Material Characterization Specific Gravity (gm/cc) 1. 189 1. 126 1. 153 1. 147 1. 120 1. 150 Full Cone Penetration (1/10 mm) 291 350 380 342 340 433 Aging in Water @ 60°C (Days to Failure) 57+ 57+ 57+ 57+ 57+ 6 Temperature Cycling (Cycles to Failure) 75+ 75+ 75+ 12 75+ 48 + denotes the test was terminated without failure. NT denotes the material was not tested. Example 73 74 Hydrophilic Additive Elvanol™ 71-30 Vinol™ 540S PVP™ K-90 Waterlock™ A-200 Waterlock™ G-400 17.5 Aridall™ 1125 4.0 Basic Oxide Calcium Oxide 26.4 30.4 Acidic Material Versadyme™ 288 54.1 62.6 Hycar™ 2000X-162 CTB Ricon™ 131/MA Suspending Agents Cab-O-Sil™ M-5 2.0 2.0 Example 73 74 Material Characterization Specific Gravity (gm/cc) 1.201 1.174 Full Cone Penetration (1/10 mm) 463 342 Aging in Water @ 60°C (Days to Failure) 2 13 Temperature Cycling (Cycles to Failure) 12 75+ + denotes the test was terminated without failure. NT denotes the material was not tested. The invention is further illustrated in the following comparative examples. The materials, amounts and conditions employed in these examples are illustrative only. Example 75 One of the compositions of the present invention, Example 25 (denoted as FE25) was compared to a calcium soap-based grease (the "standard grease") in 3M's five pair and twenty five pair 3800 "super can" Buried Service Wire, (BSW) . For example, into each of the four 3M 3800B 25 pair BSW "super can" bodies was loaded about 750 grams of FE25. Two general, twenty five pair 24 gauge cables were spliced together with dry Picabond™ connectors via standard splicing procedures. Each of these splices were then positioned into a 3M 3800B BSW "super can" splice tray and correspondingly each tray was then pressed into one of the 3800B BSW kit bodies containing FE25 sealant. Similarly, the balance of the samples were prepared. The Tip to Ring insulation resistance of all splice assemblies were then measured (500 VDC using a General Radio model 1864 megohmeter) . Freeze/Thaw in Water Description: The Freeze/Thaw samples were soaked under 30.5 cm of water contained in a 19 liter pail. Each sample was placed vertically in the water with its cable ends strapped to the outside of the container. The container was placed within a Thermotron™ wp762 environmental chamber and cycled for 50 cycles between -40°C and 60°C. The total time for each cycle was 12 hours. Each cycle consisted of 5 hour dwells at each temperature extreme and one hour transition time between the temperature extremes. Criteria for Failure: The samples should maintain insulation resistance of greater than 100 mega ohms (1.0 E8 ohms) when subjected to test requirements described above. Results: Table 1 provides the sample installation temperature, initial and final insulation resistance, and the final physical condition. Note that the insulation resistance was measured in ohms and stated in scientific notation. Conclusion: This example demonstrates that the 3800B and the 3800 sealed with FE25 provided excellent protection while submerged under freezing and thawing water. None of the samples showed any signs of physical damage and all four samples were completely reenterable. All of the samples sealed with a typical grease failed to maintain insulation resistance above the required 1.0 E8 ohms. These samples all contained water within the splice bundle. Example 76 Dielectric Breakdown Test Seven samples of the standard UR connector (filled with hydrocarbon based grease) and seven UR's (filled with FE25) were placed in a 5% salt solution according to Rural Electric Authority, REA, standard PE-52 Section 9.63 (wet). Each of the 14 samples was surged with an increasing amount of voltage until failure in the insulation occurred. (The breakdown occurs between the copper conductors and the salt water.) Table 2 illustrates the voltage breakdown values. Table 2 * Maximum effective reading of meter was 25.0 KV. This sample exceeded that reading. This example demonstrates that the FE25 sealant exhibits dielectric breakdown levels surprisingly greater than the standard grease used in copper joining connectors. There are three possible locations for the breakdown to occur: between the salt water and, a) the polycarbonate to the element, b) the filler material to the conductors, c) the insulation outside of the connector. The majority of the failures took place within the wire channel.

Claims: What is claimed is: 1. A moisture-reactive composition free of insulating oil and comprising at least one liquid polycarboxylic acid or anhydride; at least one inorganic basic oxide capable of hydrolyzing; at least one hydrophilic material; and at least one suspending agent. 2. The composition of claim l wherein said polycarboxylic acid or anhydride is present at a concentration of from 35 to 70 parts by weight; said oxide is present at from 15 to 50 parts by weight; said hydrophilic material is present at from 1 to 25 parts by weight; and said suspending agent is present at from 0.1 to 10 parts by weight, all based on the total weight of said composition. 3. The composition of claim 2 wherein said acid or anhydride is present at from 45 to 60 parts by weight; said oxide is present at from 25 to 35 parts by weight; said hydrophilic material is present at from 8 to 20 parts by weight, and said suspending agent is present at from 1 to 4 parts, all based on the total weight of said composition. 4. The composition of claim 1 wherein said acid or anhydride is a dimer acid having a mono-acid content of less than 2 percent by weight. 5. The composition of claim 1 wherein said hydrophilic material is polyvinyl alcohol. 6. The composition of claim 3 wherein said polyvinyl alcohol is from 99 to 99.8 percent hydrolyzed. 7. The composition of claim 1 wherein said suspending agent is amorphous fumed silica. 8. The composition of claim 1 wherein said oxide is selected from the group consisting of calcium, barium, magnesium, zinc, strontium and copper I oxides, and said acid or anhydride is selected from the group consisting of dimer and trimer acids, and carboxyl-functional polybutadiene or the anhydride equivalent thereof. 9. The composition of claim 6 wherein said oxide is calcium oxide. 10. A moisture resistant splice assembly comprising at least two conductors spliced to each other and the moisture reactive composition of claim 1 surrounding and in intimate contact with said conductors. 11. The splice assembly of claim 10 wherein said polycarboxylic acid or anhydride is present at a concentration of from 35 to 70 parts by weight; said oxide is present at from 15 to 50 parts by weight; said hydrophilic material is present at from 1 to 25 parts by weight; and said suspending agent is present at from 0.1 to 10 parts by weight, all based on the total weight of said composition. 12. The splice assembly of claim 10 wherein said acid or anhydride is a dimer acid having a mono-acid content of less than about 2 percent by weight; said oxide is calcium oxide; said hydrophilic material is polyvinyl alcohol, and said suspending agent is amorphous fumed silica.

Inventors: HAUGEN HARTWICK A, HIBBARD WILLIAM A, HAUGEN, HARTWICK, A., HIBBARD, WILLIAM, A.
Applicants: MINNESOTA MINING & MFG, MINNESOTA MINING AND MANUFACTURING COMPANY
Application year: 1991
Main classification: C09K3
IPC codes: C08K3, C08K5, C08L101, C09K3, H01B3, H01B7