US1594982A - Oil composition for saturating cable wrappings - Google Patents

Description

. trolatum or grease of suitable consis-' Patented Aug. 3, 1926.

ALBERT A. SOKERVILLE, OF FLUSHING, NEW YORK, ASSIGNOR 0]! 'IWO-THIRDS TO B. '1. VANDERBILT COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORA- TION OI NEW YORK.

OIL COMPOSITION FOR SATUBA'IING CABLE WRAIPIN No Drawing.

This invention relates to an improved oil or grease composition for use in saturating the paper or other materials used as-a wrapper for electrical cables.

In the manufacture of cables for use as conductors of electrical current, the wrap ping of paper or other material is saturated with a suitable oil composition, such as petency by passing the wrapped cable through a hot saturating or impregnating bath of the oil composition. The oil or grease is, in general, such as is not fluid below 30 C. and has a viscosity of not less than 100 seconds at 100 C. as measured by the Saybolt viscosimeter. In the manufacture of continuous lengths of cable, the impregnating bath is maintained at high temperature for long periods of time. The result, however, is that the saturating bath rapidly deteriorates in its insulating properties, and, at more or less frequent intervals of time, it is necessary to remove the bath and replace it with a fresh bath of suitable insulating properties. Moreover, after the impregnating bath is used, and after the wrapped and. saturated cable is enclosed in the usual lead casing, the saturating composition undergoes further deterioration under the influence of electrical stress and of the elevated temperatures to which it may be subjected in use.

The present invention provides an improved saturating or impregnating compo-- sition which can be used for greatly prolonged periods of time, as compared with the ordinary saturating or impregnating composition,-and which is stabilized so that it will resist deterioration, both during the saturating or impregnating operation, and during the subsequent use of the finished cable as an electrical conductor.

According to the present invention, the petrolatum or grease composition, which is to be used for saturating the wrappings of cables, has compounded therewith a small .amount of a nitrogenous stabilizing agent which will retard orprevent deterioration, both during the saturating treatment and during the subsequent use of the cable as an electrical conductor. When the cable wrapping is saturated with such a stabilized composition, the resulting cable may be considered .as a substantially. permanent con- Application filed January 8, 1926. Serial No. 80,065.

struction with a .minimum'liability of deterioration of the saturating or impregnatmg oil composition with which the wrapping is saturated.

The stabilizing materials which are added, in small amounts, to the oil composition used for saturating the wrappings of cables, may be of a somewhat varied character. Of particular advantage are compounds within the "group of organic amines, or imines, and particularly condensation products of aldehydes with ammonia or with amines. In general, the compound so added should be non-volatile at the temperature at which the saturating compositlon is used, and it should also be stable in the sense that it: is not decomposed into volatile or objectionable compounds at such temperature 'of use. The material added should also be soluble in the oil or grease composition to such an extent that it Will form a homogeneous admixture therewith. An oil of the general class of petroleum oils and containing a stabilizer comprising specifically the condensation product of an aldehyde and a nitrogenous base is claimed in my copending application Serial No. 103,- 374, filed Apr. 20th, 1926.

The stabilizing ingredients or ingredient may be added directly to the-oil, if readily soluble therein, or the dissolving of the stabilizing material may be promoted by heating, or the material may be first dissolved in a solvent such as-benzol, and the benzolmonly used for impregnating the paper wrapping of cables, has added thereto a small amount. e. g. 0.5% to 1% of a condensation product of acetaldehyde with anilin, the admixture being promoted by dissolving the condensation product in benzol and then intimately admixing the benzol solution with the saturating bath. When the resulting composition is used for saturat ng the paper wrapping of cables, by passing the cable through the hot saturating bath,

the bath .will retain high insulating proper ties for long periods of time. In fact, the bath mav increase in its electrical resistivity from that of the original oil being in this respect. radically different from the ordinary saturating bath which rap1dl v deteriorates in its electricalresistivity. Not only is 1t possible to use the saturating bath for greatly prolonged periods of time, but the resulting cables which have the wrappings satu rated with the improved stabilized compos1- tion, will likewise. resist deterioration 1n use, thus being a more valuable and 1mproved form of cable construction.

The mineral oil composition used for uppregnating cable wrappings may have I'OSlIl oil or pine oil added thereto, to impart somewhatdifi'erent characteristics to it, such as a change in viscosity and flow point. When such oils are added, the nitrogenous stabilizing ingredient or ingredients may be added to a mineral oil or with a pine oil or rosin oil. 7

Instead of using a condensation product of acetaldehyde and anilin, the condensation product of aldol and alphanaphthylamine can be similarly pod.

While I do not wish to limit myself by any theoretical explanations of the action of the stabilizers used in the present invention, yet I believe their actions to be due to prevention of oxidation at the elevated temperatures to which the oils are subjected in use. Although the stabilizing ingredients are used only in very small amounts,

not usually exceeding about 2%, and in some cases being only a fraction of a per cent. nevertheless they appear to impart remarkable stability to the oil compositions from the standpoint of preventing the usual rapid deterioration of such oil compositions at elevated temperatures.

Instead of using the particular stabilizing materials above mentioned, other nitrogenous stabilizing materials can be used. Among these may be mentioned other members of the group of organic amines and imines, such as homologues of anilin, benzidin and its homologues, paraphenylenediam-inc, and other aromatic diammes, alpha or beta naphthylamine, etc. Among the condensation products of aldehydes and ammonia or amines may be mentioned, in addition to those above given, other condensaacetaldehyde with anilin (both the acid and i the neutral condensate), the condensation product of formaldehyde with anilin, the condensation product of acetaldehyde with ortho or para toluidine, etc., the condensation product of furfuraldehyde with am-' monia or with aniline or orthotoluidine, etc.

It will thus be seen that the present invention is of more or less general application to petroleum oil compositions of the kind used for saturating cable wrappers imparting to these oils improved stabilized properties such that they resist the usual deterioration and can be used for long periods of time without losing their valuable electrical insulating properties. It will also be seen that-,in the case of the cables which have their wrappings saturated with the new composition, the resulting cables are themselves of an improved character, because of the stabilized nature of the saturating composition with which the cable wrappings are saturated.

'I claim v 1. An improved composition for saturating cable wrappings, comprising petrolatum and a small amount of a nitrogenous stabilizing material which retards loss of electrical resistivity of 'the saturating material-at an elevated temperature during the saturating of the cable w-rappings, and subsequently in the use of the cables as electrical oonductors.

2. An improved composition for saturat-f ing cable wrappings, consisting of a petroleum oil of suitable consistency and a small amount of an inert nitrogenous stabilizing material substantially free from acid radicals which retards loss of electrical resistivity of the saturating material at an elevated temperature during the saturating of the cable wrappings, and subsequently in the use of the cables as electrical conductors.

3. In a process for treating cable wrappings, the step of impregnating the cable wrapping with a composition comprising a petroleum oil of suitable consistency and a condensation product of a nitrogenous base and a carbonyl compound.

- In testimony whereof I afiix my signa ture.

ALBERT A. SOMERVILLE.