US2491120A - Flushing compositions - Google Patents

Description

Patented Dec. 13, 1949 FLUSHING COMPOSITIONS Clarence M. Loane, Hammond, and Thomas H.

Rogers, Chesterton, Ind., assignors to Standard Oil Company, of Indiana Chicago, 111., a corporation No Drawing. Application December 29, 1945, Serial No. 638,487

3 Claims. (Cl. 260-4571) This invention relates primarily to flushing oils and particularly to flushings oils of the type which may be used in the lubricating systems of motors, such as turbines, engines, etc., for a period of time during the operation thereof in place of the usual lubricating oil.

It is an object of this invention to provide a flushing oil that has improved flushing and solvent properties making it suitable for removing deposits of lacquer or varnish and lacquer-bonded solid particles, sludge deposits, etc., from the internal and operating surfaces of motor parts, and particularly the sludge formations and rest accumulations in a turbine and other industrial circulating lubrication systems due to operation of the circulating oil over long periods. It is a further object to provide a flushing oil that has suitable lubricating properties so that the oil may be used while the unit is operating without danger of scoring bearings and other contacting surfaces. This is particularly important in turbines where the flushing oil is preferably used as the lubricant for a considerable time in order to allow suflicie'nt contact between the flushing oil and the deposits. It is yet a further object to provide such a flushing oil having no carcinogenic properties, thus enabling its safe use under reasonable conditions by unskilled personnel. It is minimum reduction in the solvency power of the solvent.

Our improved flushing oil comprises-predominantly alkyl polycyclic aromatic hydrocarbons having not more than 3 condensed aromatic rings and wherein at least part of the alkyls contain more than one carbon atom. These alkyl polycyclic aromatics are preferably a mixture of mono-, di-, and trimethylnaphthalenes and alkylated naphthalenes and methylnaphthalenes such as propylated, butylated, amylated, etc, naphthalenes and methylnaphthalenes. In our preferred flushing oil we use as the principal solvent a hydrocarbon mixture, produced by the catalytic conversion of aliphatic and alicyclic hydrocarbons by a process known as hydroforming, and known as hydroformer polymer or "bottoms," and as an additive for increasing the viscosity of the solvent, to improve its lubricating properties without inhibiting or reducing its solvent properties, we prefer to use hydroformer polymer" which has been alkylated by treatment or reaction with an olefin, for example, propylene, butylene, amylene, propylene polymer, hutylene polymer, ethylene polymer, etc. an'd'mixtures thereof.

Although we speak of the alkylated material as an additive, it may comprise a very substantial portion of our flushing oil and in some instances is satisfactory when used alone. In general,

however, our flushing oil will comprise a mixture of about 5 to percent of hydroformer polymer and the balance, at least 5 percent, alkylated hydroformer polymer" depending on the viscosity requirements of the finished oil. For flushing turbine lubricating systems we prefer that our flushing oil meet the viscosity specifications of a typical turbine oil and may range in viscosity from about 35 to about 600 seconds Saybolt Universal at F. and preferably from about to about 350. A flushing oil within this viscosity range can be run for a substantial period, e. g. several weeks, in a turbine and thus thoroughly clean by contact all the surfaces where deposits may occur. This method of cleaning turbines represents a marked improvement over prior mechanical methods and solvent methods when the turbine is down. :Ihe mechanical methods are tedious and costly while the prior solvent methods do not allow for suflicient contact time between the solvent and the deposits.

Hydroformer "polymer" (not a true polymerized material) is a complex mixture of monoand polycyclic aromatics. As an example, a' sample having a gravity of about 12.0 A. P. I. has from vacuum distillation the following composition by volume:

Fraction Components 0-2 per cent Toluene. 2-8 per cent Xylenes. 8-14 per cent l, 3. 5-Irlmethyl benzene. 14-17 per cent 1, 3, 4-lrimcthyl benzene. 17-22 per cent.. 1. 2. S-Trimethyl benzene. 22-27 per cent Tetramethyl benzenes. 27-37 per cent... Naphthalene. 37-50 per cent... Monomethylnnphthalenes. 59-61 per cent. Dlphenyl. 61-74 per cent Dimethvlnaphthalenes. 74-78 per cent. Methyldinhenyls. 78-83 per cent... 'lrimethylnaphthalenes. I 83-87 per cent. Fluorene.

87-89 per cenL... Mcthylflucrenes. 89-04 per cent Anthrnoene and Phemmthrene. 94-97 per cent.. Methylanthrocenes and Methylphenanthreues. 97-98 per oonL... Pyrene. 98-100 per cent. Tctracyclics and Higher.

From the above analysis of the polymer it is seen that it is composed predominantly of methyl and po-lymethylbenzenes, naphthalene and Y methyland polymethylnaphthalenes. Its gravity before re-running may vary from about 10 A. P. I. to about 13 A. P. I. and its approximate 1 12 A. P. I. A. P. I.

Per cent Per cent Methyland polymethylbenzenes Naphthalene and monomethylnaphthalenes...

Dlmethylnaphthalenes 16 The tetracyclic andhigher condensed aromatics are eliminated by rerunning the hydroformer "polymer" as produced to an end point of not more than 650 F. and preferably 625 F. in order that our solvent material may be free oi. these condensed polycyclic aromatics of more than three rings and thus safe from the point of view of possible carcinogenic properties. Consequently in our preferred solvent the composition of the principal constituents will be somewhat altered depending on how much material is eliminated upon rerunning.

Our preferred solvent is approximately a 90% cut of hydroiormer polymer" of about 10-11 Y A. P. I. gravity having the following typical inspection data:

As pointed out above, the polymer" is a product oi the well-known hydroforming process described in U. S. 2,335,596 and which. in general, comprises treating a virgin or cracked naphtha or a mixture of both with a solid, porous hydroiorming catalyst at a temperature in the range of about 850 F. to about 1050 F., preferably in the presence of hydrogen. Suitable catalysts are oxides of metals of groups 11 to VI of the periodic system, particularly oxides of the VI group metals such as chromium and molybdenum, preferably supported on alumina or magnesia. Excellent catalysts can be prepared by depositing about 4 to about 10 percent molybdenum upon an activated alumina. Suitable space velocities for hydroforming fall within the range of about 0.2 to about 4 volumes of liquid charge stock per hour per volume of catalyst space. About 0.5 to about 8 mols of hydrogen can be charged to the process with each mol of naphtha feed stock.

The hydroformer polymer" is a product of fractionating the reaction products from the hydroforming process and it has a boiling range of 350 F. to about 750 F. The composition of the hydroformer polymer" may vary to a minor extent depending upon the specific catalyst, the age of the catalyst, and particularly the type of feed stock. We prefer to use a conventional heavy naphtha feed stock having a gravity of about 40 to 65 A. P. I.

Although we prefer a hydroformer "polymer as our solvent, we may use, under some circumstances. fractions of comparable boiling range comprisin principally methylated aromatics such as can be obtained from a catalytic cracking refractory stock of the type described in U. S. 2,335,596, the distillation of coal tar, and solvent extrats of various hydrocarbon mixtures.

The.;alkylated hydroformer polymer is a material which is the reaction product of the alkylation of; hydroformer polymer produced in the above described manner with an olefin including a mono-olefin and olefin polymer. Olefins which we may use are preferably those of less than six carbon atoms. e. g. propylene, butylene, amylene, and the like. and polymers of these oleflns such as ethylene polymer. propylene polymer, isobutylene polymer, isoamylene polymer, and mixtures of oleflns and olefin polymers. Although the alkylation may be carried out by any of the wellknown allrylation processes, we prefer to produce our alkylated hydroformer "polymer by treating the hydroformer polymer preferably of 650 F. end point with an anhydrous toluene sulfonic acid in accordance with the teachings of Wadsworth et al. Serial 609,882, filed August 9, 1945. now U. 8. 2,462,792. The process for carrying out the alkylation may comprise, as for example, treating a liquid charging stock, of about 17% gallons (66.7 kg.) of a mixed mono-, diand trimethylnaphthalene fraction of hydroformer polymer" with about 10 mol percent (7.35 kg.) of technical toluene sulfonic acid. A butane and butylene gas stream is introduced in the treating or reaction zone at the rate of about 0.2 cubic foot per minute and the rate is subsequently increased to about 0.5 cubic foot per minute. The pressure in the reaction zone should be about 30 pounds p r Square" inch and the temperature in the range of about 265-285" F. The product of this reaction will have a boiling range of about 608-662 F., will be light yellow in color, will have a viscosity of about 174 seconds Saybolt Universal at F. and will have a refractive index (N a 1.5620. Substantially the same process can be used for preparing dibutylnaphthalenes, dipropylnaphthalenes. and naphthalenes alkylated with propylene and butylene polymers, resulting in alkylated products having a viscosity in the range of 100 to 1000 seconds Saybolt Universal at 210 F.

As was pointed out with regard to our solvent material, the alkylated naphthaienes may be produced, as for example, by alkylating naphthalenes or allrylnaphthalenes from coal tar or refractory cracking stock with an olefin. including an olefin polymer. in the presence of other alkylation'catalysts, such as sulfuric acid and Friedel- Crafts catalysts such as AlCla.

We may under certain circumstances add to our fiushing oil well-lrnown additives for increasing the viscosity index, film strength, oxidation stability and/or detergent properties. Such additives are well-known in connection with their use in lubricating oils. Other modifications will occur to those skilled in the art and no limitations are intended by the above-described examples except as are contained in the following claims.

We claim: A

l. A cgrnposition composed of a catalytic reformed naphtha traction boiling within the range of fromabout 350 F. to about 750 F., and having a gravity of from about 10 A. P. I. to about 13 A. P, I. and in, combination therewith from about 5 5% to about 95% of said catalytic reformed naphtha fraction alkylated with an olefin oi at least two carbon atoms.

2. The composition oil of claim 1 wherein the olefin is an olefin polymer, the monomer oi which contains less than 6 carbon atoms.

3. A flushing oil composition composed essentially of fromabout 5% to about 95% of methylated naphthalenes and from about 5% to about 95% 01' olefin polymer alkylated naphthalenes having a Saybolt Universal viscosity at 210 F. and from about 100 seconds to about 1000 seeonds. said polymer being the polymer of olefin monomers having from 2 to 5 carbon atoms inelusive.

ClL-ARENCE M. LOANE. THOMAS 1!. ROGERS.

REFERENCES CITED file of this patent:

6 mm sums rams Number Name Date Guinot et a1 Apr. 13, 1948 Boday Feb. 11, 1947 Ruthrufl Nov. 5, 1946 Shankland Mar. 5, 1946 Lieber Nov. 28, 1944 Sachanen et a1. Feb. 15, 1944 Marschn er Nov. 30, 1943 Loane Apr. 6, 1943 Matheson Apr. 7, 1942 Edgar Nov. 18, 1941 Sweeney et a1. Apr. 2, 1940 Barth Feb. 20, 1940 Pevere June 21, 1938