US3268449A - Lubricating compositions containing resinous polysulfides - Google Patents

Description

Aug. 23, 1966 l.. coLAs Erm. 3,268,449

LUBURICATING COMPOSITIONS CONTAINING RESINOUS POLYSULFIDES Filed May 1s, 196s a0/S C0495 fR/wm 06h00/IE5 United States Patent C 3,268,449 LUBRICATING COMPDSITIONS CONTG RESINOUS POLYSULFIDES Louis Colas and Bernard Dernoures, Lyon, and Yolande f Bourgau, Neuville-sur-Saone, France, assignors to Society, Progil, Paris, France Filed May 13, 1963, Ser. No. 280,005 Claims priority, application France, May 15, 1962., 897,599 2 Claims. (Cl. 252-488) The present invention relates to additives for lubricants and particularly to products which are capable of conferring extreme pressu-re properties upon an oil, so as to render it more especially suitable for use as a cutting oil.

It is current practice to incorporate various additives in lubricants for the purposes of improving the lubricating qualities, inhibiting corrosion, serving as dispersants and/or modifying the viscosity. In the very important case of cutting oils, for use under severe conditions of operation Where the cutting tool exerts a high pressure upon the workpiece, suitable additives are particularly useful. -In fact, at the extreme pressures developed at the edge of the tool, the lubricating iilm formed by a normal oil has a tendency to become disrupted, which removes the lubrication from the very point where it should #be present, thus involving the known disadvantages. The inclusion of an additive has the object of causing the formation of a second, more resistant lubricating film on the edge -of the tool and on the workpiece in contact therewith.

A large number of different additives are known for heavy oils, such as lard oil, sulphur-containing oil, chlorinated organic derivatives, such as chlorinated paraiiins, alkyl `or aryl phosphates, thioethers and dithiophosphates. When the oil contains a mixture of sulphur-containing compounds, on the one part, and chlorinated organic derivatives, on the other part, the eilicacy of such additives appears to be better. However, lit has been found that substances containing both sulphur and chlorine, particularly chlorinated chlorodibenzyl-disulphide containing 20% of S and 13'% 0f Cl are not eiective.

The present invention relates to an improvement in additives for lubricants, which is particularly advantageous in the formulation of cutting oils which are required to be used under extreme pressure conditions. The additives according to the invention have an efficacy at least as good or better than that of the most suitable extreme pressure `adjuvants utilised at the present. Also, they have the advantage over the latter of being more readily preparable and of being applied with greater facility. In fact, the new additives contain both chlorine and sulphur, in the same chemical compound, which avoids the admixture of several additives separately containing Cl and S. Tests to ascertain the `optimum amount of each one is thus avoided.

The new additives according to the invention consists of resinous halogenated aryl sulphides which are soluble in hydrocarbons. These additives are, particularly, halo aryl polysulphides having one or more halogenated aromatic rings, which if desired can carry side chains containing halogen and/or -other substituents.

According to a preferred embodiment of the invention, the additives added to the :lubricants in accordance with the invention are chlorophenyl polysulphides, particularly polychlorophenyl polysulphides. Excellent results are obtained with polychlorophenyl polysulphides containing, by weight, 44 to 55% of chlorine and 15 to 25% of sulphur. Although the chemical structure of these substances is not precisely defined, it is probable that these compounds can be represented, at Ileast approximately, by the general formula:

Xp Xm in which X is at least one halogen; the numbers of halogen atoms, "m and "p, are integral numbers from 1 to 5. Preferably, they are both equal `to 3 or 4; m can be equal to 17. It required, one of these numbers can be 0 which corresponds to the absence of :a halogen from one of the nuclei. As regards the number of sulphur atoms, '71, this can vary, but is preferably about 3. Resinous polychlorophenyl polysulphides which have been used most in carrying the invention into effect have molecular weights ranging from 400 lto, 600.

The novel additives of the invention can be prepared by heating one or more halo-aryl polysulphides to such a temperature and for such a time that the compounds become resinous.

An advantageous mode of preparation consists in subjecting to moderate heating, particularly between 20 and 30 C., a reaction mixture comprising a chlorosulphide and a poly-halo-aryl compound, in the presence of a Friedel-Crafts catalyst. The polysulphide so formed is then heated to a temperature of to 250 C. After separation of any excess reactants and washing, the resinous product `obtained is added to the lubricant which is to be improved, either directly or after rst being dissolved in a suitable solvent.

Depending upon the nature of the lubricant and the purpose for which it is intended, the amount of additive added according to the invention can range over wide limits, for example from 0.2 to 20%. For high pressure cutting oils, suitable amounts are from 2 to 10% by weight. It is found, in this case, that there is a very great elevation of the frictional limit and a considerable reduction in the Wear 0f the tool.

In order to explain the invention, several specific examples are described below, by Way 0f illustration only.

Example I A sulphide of intermediate composition between the diand trisulphides of lbis-trichlorophenyl Was prepared in the following manner.

20 g. of AlCl3 was added to 817 g. of technical trichlorobenzene (TCB), the mixture being heated to 45 C. under stirring, and there was then added in portions, over two hours, 405 g. of S2Cl2 previously diluted with 363 g. of the same TCB. The latter technical product contained, by weight, 30% of 1,2,3-TCB, 65% of 1,2,4-TCB and 5% of 1,2,4,5 and 1,2,3,4-tetrachlorobenzenes.

On discontinuing the addition of sulphur dichloride, agitation was maintained for 1/2 hour at 45 C. and then the reaction mixture was heated for 2 hours at 80 C. The reaction mixture was then poured into Water to destroy the catalyst the destruction and elimination of which was terminated by washing with dilute HC1, followed by washing with a dilute solution of sodium carbonate and washing with water until the mixture was neutral. The organic solution was decanted olf and subjected to distillation under 20 mm. pressure until the boiling point had attained 193 to 200 C. There was thus obtained, after elimination of 260 g. yof TCB, 950 g. of resinous chloroybenzene polysulphides containing 49.0% of chlorine and 19.0% of sulphur.

A solution of these polysulphides `at about 70% concentration was prepared in the oil known as 370 Neutral (registered trademark), so that the solution contained 14% of sulphur and 35% of chlorine. This concentrated solution of the resinous product was tested as an additive as an oil intended for use `as a cutting oil.

Friction in Wear on the Percent ci additive in the oil kg. hearings 1n nun.

Very similar results were also obtained with the same additive in another oil currently in use, of paraiinic type, known under the trademark 100 Neutral.

Example 2 Resinous polysulphides prepared according to the method of Example 1 were obtained, which contained 47.4% of chlorine and 21% of sulphur. They were dissolved at 33.3% concentration in the parafrinic oil known as 350 N.v In the accompanying graph, curve I shows the variations in the frictional pressure as a function of the percent content by weight of the concentrated solution in the oil. Curve Il indicates the frictional pressures yfor the same proportions of a conventional commerciallyavailable additive, containing chloroparafns and known under the trademark N-490l of OROGIL Society. 1t will be seen that the haloaryl polysulphide according to the invention is more effective in an equal amount.

Example 3 Friction in Wear on the Percent of additive in the oil kg. bearings 111 IDII'L Example 4 Polysulphides prepared as in Example 3 were obtained though with the addition of more free sulphur to the SZClz (90 g. in 405 g. of S2Cl2), giving 23.3% of sulphur and 43.9% of chlorine. An 80% solution of these polysulphides in 350 N oil was obtained and was added to a spindle parafnic oil with the following results:

Friction in Wear on the Percent oi additive in the oil kg. bearings in mln.

o 80 2. 5 2 110 o. 6 4 125 O. 6 8 140 0. 6

Example An additive was prepared by the method of preparation of Example 1, but using a mixture of 80% by weight of trichlorobenzenes and by weight of 1,2,4,5 and 4 1,2,3,4-te-trachlorobenzenes, particularly rich in 1,2,3 ,4- tetrachlorobenzene. The product so obtained reduced the wear on bearings to 0.3 mm., when added to a cutting oil composed of heavy alkyl-benzenes of molecular weight about 300, known under the trademark Progiline 152.

The foregoing examples prove that the wear on bearings is considerably diminished with quite low amounts of additives, of the order of 2%, and that this does not vary in practice with increasing proportions of additive. Decrease in wear from 2.5 to 0.6 mm. at 100 kg. constitutes a considerable improvement. It will also be seen that there is a suitable improvement in relation to friction, as the frictional pressure increases with the content of additive.

During .the tests described above, no foam formation was caused by the presence of the additive according to the invention. On the other hand, corrosion tests on cast iron plates have not revealed any attack after three days. Also after .this lapse of time, the bearings themselves were not attacked.

Example 6 The same additive as in Example 5 has been -added to the same heavy alkybbenzenes cutting oil (molecular @weight about 300), in the proportion of 8% by weight. Another sample of the same oil has been added with 8% of the known lubricant .additive which is composed of chloroparans and contains an oxidation inhibitor. Under strong charges, expressed in tkg., the following wears of bearings, in mm., have been found:

The additive of Example 5 1. 0 1. 35 1. 70 The above known additive 1. 25 1. 6D 1. 90

With the same additives in the spindle naphthenic oil Carnea 21 (trademark) of Shell Chem. Co., at the proportion of 8%, the following wearings have been stated:

The additive of Example 5 1. 25 1. 50 The above known additive l. 40 1. 85

Example 7 I II (percent) (percent) Mercapto-benzo-thiazole containing additive 20 10 Emulsifying agent (heavy alkyl-benzene sulfonate) 20 20 Naphthenic spindle oil 60 70 A 10% emulsion of 4these compositions in hard water, having a hardness of 30 French degrees, remained stable for months without settling, occurred.

On tests with four-bearings machine, the following wear diameters were found with the above soluble oils for different charges:

I--mm 0.35 0.45 0.55 1.05 1.4 II--mm 0.40 0.50 0.65 1.2

The emulsions used gave satisfactory results on known method corrosion tests with cast-iron and with copper.

We claim:

1. Lubricating composition which consists of a cutting oil having dissolved therein an amount in the range from 0.2% to 20% by Weight of at least one resinous .polysulde prepared by heating a crystallizable chlorinated polyphenyl polysultde at a temperature in the range from 80 C. to 250 C. until it ceases to be substantially crystallizable.

2. Lubricating composition which consists of a cutting oil containing dissolved therein an amount of 0.2% to 20% by weight of at least one resinous polysulde prepared by reacting a polychloro-benzene with sulphur chloride at a moderate .temperature below 80 C. in the presence of a Friedel-Crafts catalyst, heating the reaction mixture for one to `two hours at a temperature in the range from 80 C. to 250 C., and thereafter removing the catalyst by washing and separating the resinous polys'uliide formed.

References Cited by the Examiner UNITED STATES PATENTS 2,172,954 9/1939 Clark 252-488 X 2,208,163 7/1940 Prutton et al. 252-48.4 2,790,775 4/1957 Hughes et al 252-45 2,937,208 5/1960 Retter et al. 252--48J8 X 2,941,945 6/ 1960 (Fainman 25,2-45

DANIEL E. WYMAN, Primary Examiner.

I. R. MCBRIDE, L. G. XIARHOS, Assistant Examiners.

Claims (1)

1. LUBRICATING COMPOSITION WHICH CONSISTS OF A CUTTING OIL HAVING DISSOLVED THEREIN AN AMOUNT OF THE RANGE FROM 0.2% TO 20% BY WEIGHT OF AT LEAST ONE RESINOUS POLYSULFIDE PREPARED BY HEATING A CRYSTALLIZABLE CHLORINATED POLYPHENYL POLYSULFIDE AT A TEMPERATURE IN THE RANGE FROM 80* C. TO 250*C. UNTIL IT CEASES TO BE SUBSTANTIALLY CRYSTALLIZABLE.

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