Cleaner, preservative and antioxidant compositions

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BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates, generally, to water insoluble cleaners having preservative and antioxidant properties for use in cleaning insulated telecommunication cables.

2. Description of the Prior Art

The cleaning of insulated telecommunication cables, has proven particularly troublesome in the telecommunication industry. Telecommunication cables are customarily made up of one or more conductors which are surrounded by an insulating material. The one or more insulated conductors are then surrounded by a protective sheath. The voids or interstices between and around the insulating material inside the protective sheath are filled with a waterproof filling medium. The waterproof filling medium can be made of any number of materials, but typically contains hydrocarbon oils, gelling agents and other components. The waterproof filling medium contacts the insulation and acts as a waterproofing agent. Filling media adhere tenaciously to insulation and require repeated mechanical wiping away from the insulation to prepare individual insulated wires for jointing and terminating purposes.

The telecommunication industry has traditionally used solvent based cleaning agents to remove filling media, traces of dirt and moisture from electric cable and other equipment. For example, U.S. Pat. No. 5,238,504 to Henry proposes the use of a blend of terpene hydrocarbons and aliphatic or cyclic ketones for use as effective cleaners. U.S. Pat. No. 5,405,547 to Rinehart discloses a combination of diacetone alcohol and a compatible terpene fraction for use as cleaning and drying compositions. U.S. Pat. No. B1 4,411,488 to Matta discloses a combination of a terpene, surfactant and coupling agent for use as a cleaning composition. U.S. Pat. No. 4,867,800 to Dishart et al. discloses cleaning compositions which include a terpene compound and a dibasic ester for removing residues on the surface of a substrate.

These cleaning compositions provide contact surfaces which are free of filling media and other residual contaminates. However, these prior art cleaners significantly decrease the Oxidative Induction Time (OIT) of the cable. The determination of the Oxidative Induction Time of insulated telecommunication cable is a means for determining the level of stabilization of the cable and cable components. The Oxidative Induction Time is correlated to the suitability of the cable or cable component to withstand the rigors imposed by field service conditions. A decrease in the Oxidative Induction Time indicates that the cable or cable components are susceptible to oxidation. During installation and splicing operations cable components can be exposed to the atmosphere for extended periods of time which can result in extensive oxidation. In addition, some service applications require cable components to be exposed to the atmosphere throughout their useful life. Over time the oxidation of the cable components, can result in corrosion which eventually necessitates the replacement of the affected cable.

In order to maintain the Oxidative Induction Time of the cable after cleaning with conventional cleaners, the filling media, must be replaced after the splicing operation is complete. One approach for replacing the filling media is reapplication by the technician. However, this approach is not practical in the field since these filling media are very messy and tacky, making them difficult to handle.

Another approach is that disclosed in U.S. Pat. No. 4,783,226 to Senn which provides an apparatus which is used to pump a filling medium through a sealed off portion of cable. This approach is both costly and time consuming and necessitates additional equipment to complete the cable installation.

Thus, there remains a need for water insoluble cleaning compositions that not only adequately remove the filling media, but also maintain the Oxidative Induction Time of the cable so that the cable is not rendered susceptible to oxidation. However, at the time the present invention was made, it was not obvious to those of ordinary skill in this art how this need could be fulfilled, in view of the prior art as a whole.

SUMMARY OF THE INVENTION

The long-standing but heretofore unfulfilled need for water insoluble cleaners for cleaning insulated telecommunication cables which maintain the Oxidative Induction Time of the cable is now fulfilled by a cleaning composition that includes a solvent, a preservative oil and an antioxidant. Solvents useful in the present invention include aliphatic solvents, aromatic solvents, terpene hydrocarbons, aliphatic or cyclic ketones, ester solvents and chlorinated solvents. The solvent portion of the cleaning compositions of the present invention can be a combination of one or more aliphatic solvents, aromatic solvents, terpene hydrocarbons, aliphatic or cyclic ketones, ester solvents and chlorinated solvents.

Aliphatic solvents useful in the present invention include petroleum distillates, white spirit, gasolines, kerosene, mineral spirits and dearomatized mineral spirits having from eight to fourteen carbon atoms. In particular, petroleum distillates useful in the present invention include n-octane, n-nonane, n-decane, n-undecane, n-dodecane and n-tetradecane.

Aromatic solvents used in the present invention are C.sub.1 -C.sub.8 alkyl derivatives of benzene and naphthalene. Naphthalene-depleted aromatic petroleum distillates are also useful in the present invention. For example toluene, xylene, cumene, ethylbenzene, ethylmethylbenzene, meisitylene and durene are useful in the present invention.

Terpene hydrocarbons useful in the present invention include dipentene, alpha-pinene, beta-pinene, nonal, octanal, para-menthadiene, para-cymene, limonene, cedrene, turpentine, 2-methly-6-methylene-2,7-octadiene,2, 6-dimethyl-2,4,6-octadiene, and the like, and mixtures thereof.

Aliphatic or cyclic ketones useful in the present invention include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, mesityl oxide, methyl isoamyl ketone, diacetone alcohol, methyl amyl ketone, cyclohexane, diisobutyl ketone, isophorone, cyclohexanone, ethyl butyl ketone, acetophenone, cyclopentanone, and the like, and mixtures thereof.

Ester solvents useful in the present invention include ethyl acetate, isopropyl acetate, n-propyl acetate, isobutyl acetate, n-butyl acetate, amyl acetate, isobutyl isobutyrate, 2-ethylhexyl acetate, vinyl acetate, sec-butyl acetate, butyrolactone, cyclohexyl acetate, amyl propionate, ethylene glycol monoacetate, ethylene glycol diacetate, methyl benzoate, phenyl acetate, and the like, and mixtures therof.

Cholorinated solvents useful in the present invention include methylene chloride, chloroform, 1,1,1-trichlorethane, carbon tetrachloride, ethylene dichloride, trichlorethylene, propylene dichloride, perchlorethylene, monochlorbenzene, dichlorobenzene, and the like, and mixtures thereof.

Preservative oils used in the present invention include polybutene oil and mineral oil. Antioxidants useful in the present invention include 3,4-dihydro-2-methyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-ol, 2-methyl-2-(4,8,12-trimethyltridecyl)-6-chromanol, thio-diethylene-bis-(3,5,-di-tert-butyl-4-hydroxyhydrocinnamate), 2-methyl-2-phytyl-6-chromanol, 6-hydroxy-2-methyl-2-phytylchroman and 2-methyl-2-phytyl-6-hydroxychroman.

A method of cleaning and preserving insulated telecommunication cables which comprises applying a water insoluble cleaning formulation to a cable to be cleaned, said water insoluble cleaning formulation comprising a solvent, a preservative oil and an antioxidant and allowing the cable to dry whereby the Oxidation Induction Rate of the cable is essentially the same as that prior to cleaning, is also disclosed.

Thus it is understood that a primary object of this invention is to advance the art of insulated telecommunication cable cleaners by providing a water insoluble cleaner which does not decrease the Oxidative Induction Time of the cable or cable components.

This and other important objects, features and advantages of the invention will become apparent as this description proceeds.

The invention accordingly comprises the features of water insoluble cleaning compositions for cleaning insulated telecommunication cables which maintain the Oxidative Induction Time of the cable components that will be exemplified in the description hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts one embodiment of the invention showing a base section, a test section and a control section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to water insoluble cleaning compositions, having preservative and antioxidant properties for use in cleaning and preserving insulated telecommunication cable. The water insoluble cleaners of the present invention include a solvent, a preservative oil and an antioxidant. In a preferred embodiment, the present invention is directed to a cleaning composition which includes from 80 to 98.45 percent by weight solvent, from 0.5 to 20 percent by weight preservative oil and from 0.05 to 1.0 percent by weight antioxidant. In a more preferred embodiment, the composition includes from 80 to 98.45 percent by weight solvent, from 2.0 to 8.0 percent by weight preservative oil and from 0.09 to 0.9 percent by weight antioxidant. In a most preferred embodiment, the composition includes 94 percent by weight solvent, 5.88 percent by weight preservative oil and 0.12 percent by weight antioxidant.

The cleaning compositions of the present invention are effective, in general, for removing filling media and displacing water or moisture as well as maintaining the Oxidative Induction Time of the cable. The cleaning compositions of the present invention, are effective at inhibiting oxidation of cable components. The Oxidative Induction Time of the cable or cable components cleaned with the inventive compositions are not significantly reduced and remain substantially the same as untreated, intact cable in which the filling media has not been removed.

The solvent portion of the cleaning compositions of the present invention can be a combination of one or more aliphatic solvents, aromatic solvents, terpene hydrocarbons, aliphatic or cyclic ketones, ester solvents and chlorinated solvents. In particular, aliphatic solvents useful in the preparing the compositions of the present invention include aliphatic petroleum solvents such as petroleum distillates, white spirit, gasolines, kerosene, mineral spirits, and dearomatized mineral spirits having from eight to fourteen carbon atoms. For purposes of the present invention, petroleum distillates are generally defined as a highly complex mixture of aliphatic paraffinic and cycloparaffinic (naphthenic) hydrocarbons derived from cracked or distilled petroleum. Such mixtures include a mixture of any of naphtha of several grades, gasoline, kerosene, fuel oils, gas oil, lubricating oils, paraffin wax and asphalt. For example, aliphatic solvents include compounds having from eight to fourteen carbon atoms. Aliphatic solvents such as n-octane, n-nonane, n-decane, n-undecane, n-dodecane and tetradecane are suitable for use in the present invention. In particular, suitable solvents useful in the present invention include aliphatic solvents having a flash point from 140.degree. F. to 190.degree. F. The aliphatic solvents useful in the present invention preferably have a flash point of 170.degree. F. Other suitable petroleum distillates useful in the present invention, are known in the art, such as for example, those described in CAS# (Chemical Abstracts Service) No. 64742-47-8.

Aromatic solvents useful in the present composition include C.sub.1 -C.sub.8 alkyl derivatives of benzene and naphthalene, such as toluene, xylene, cumene, ethylbenzene, ethylmethylbenzene, meisitylene, durene and the like and mixtures thereof. Naphthalene-depleted aromatic petroleum distillates are also useful in the present invention.

Other specific commercially available aliphatic and aromatic solvents suitable for use in the present invention, are known in the art, such as for example, those described in Industrial Solvents, 3rd Ed., E. W. Flick, Ed., Noyes Data Corp. (1985), pp. 57-83.

The terpene hydrocarbons useful in the present invention include dipentene, alpha-pinene, beta-pinene, nonal, octanal, para-menthadiene, para-cymene, limonene, cedrene, turpentine, 2-methly-6-methylene-2,7-octadiene, 2,6-dimethyl-2,4,6-octadiene, and the like, and mixtures thereof.

The aliphatic or cyclic ketones useful in the present invention include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, mesityl oxide, methyl isoamyl ketone, diacetone alcohol, methyl amyl ketone, cyclohexane, diisobutyl ketone, isophorone, cyclohexanone, ethyl butyl ketone, acetophenone, cyclopentanone, and the like, and mixtures thereof.

The ester solvents useful in the present invention include ethyl