US2633471A - Wax modifying agent - Google Patents

Description

Patented Mar. 31, 1953 f WAX MODIFYING AGENT Eugene Lieber, Chicago, Ill., and Aloysius F. Cashman, Staten Island, N. Y., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application December 1, 1949, Serial No. 130,606

2 Claims. (Cl. 260-407) The present invention relates to the art of producing wax modifying agents particularly those which may be employed for reducing the pour point or waxy lubricating oils or in connection with processes for dewaxing oils containing paramnic wax or in any other process or composition in which a wax structure is to be modified by reducing the crystal size. The invention will be fully understood from the following description.

In U. S. Patent 2,251,550, granted to E. Lieber, there was described a process of producing an effective wax modifying agent by heat condensation-polymerization of an acid chloride which had been derived from fatty acids containing to 20 carbon atoms. The production of such a material required a step of converting the fatty acid into a fatty acid chloride prior to the heat treatment.

It has now been found, in accordance with the present invention, that satisfactory wax modifying agents may be prepared by the direct pyrolysis of fatty acids and the like. For this purpose, aliphatic carboxylic acids containing 10 to 30 carbon atoms per molecule, the range of 12 to 22 carbon atoms being more generally preferred, are heated at a temperature of 400 F. to 800 F., preferably 500 F. to 700 F., for a period of 1 to 20 hours, more commonly from 4 to 10 hours. While normal atmospheric pressure may be used, reduced pressures are often advantageous in carrying out this process. It is enerally advantageous to conduct the heat treatment in the presence of a heat conducting material of large surface area such as steel wool, although such material is not required. The resulting product may be refined in various ways, such as by filtration or distillation to remove raw materials and low boiling condensation products, or by solvent extraction, clay treating, etc.

The exact nature of the chemical process involved is not known, but it is believed that the process is primarily a dehydration-condensation reaction.

The aliphatic acids employed in the process of the present invention may be straight or branched chain compounds, saturated or unsaturated, and may be monobasic or polybasic. Examples of the more preferred acids include stearic acid, palmitic acid, margaric acid, lauric acid, oleic acid, sebacic acid, coconut oil acids, wax oxidation acids, and the like.

The hydrocarbon base stocks into which the wax modifying agents of the present invention are incorporated are preferably waxy mineral heated at 600 F. for 6 hours.

lubricating oils such as a paraflinic lubricating oil base stock or a mixed base, which may have been subjected to any one or more of the commonly used refining steps, such as distillation, solvent extraction, acid treating, clay treating, etc., as Well as partial dewaxing. Such oil base stock may either be one which is within the known lubricating oil viscosity range or it may be an oil of much lower viscosity, such as a gas oil used in the preparation of hydraulic oils, etc., and which may have a viscosity as low as 40 seconds Saybolt at 100 F. Solid hydrocarbon base stocks maybe used, such as parafiin wax for hot melt coating of paper.

In carrying out the invention it is desirable to use the wax modifying additive in proportions of about 0.1 to 5% based on the lubricating oil base stock, although usually 1% is sufiicient for most purposes. It will be understood that different oils require slightly different amounts of the material to produce a given drop in pour point. and likewise material prepared from different types of acids vary somewhat in their pour depressing stren th.

The wax modifying agents of the present invention may be used in connection with the process for dewaxin hydrocarbon oils and then added either to the oil to be dewaxed or to the oil after it has been diluted with naphtha or with other su table dewaxing solvents. The mixture is chilled to the wax separating point and the actual separation may be conducted either by filtration, sedimentation or centrifugation. In any case it will be found that the presence of a relatively small amount of the material, say 1% more or less. will considerably increase the ease with which the separation is accomplished and increase the rate at which chilling may be carried out.

The desirable results obtained by the use of the additives described in the present specification may be illustrated by the following example which, however, is not to be considered as limiting the scope of the invention in any way.

Example 400 g. of commercial stearic acid and 10 g. of steel wool were placed in a Claisen flask and The product was recovered by vacuum distillation to 600 F. under a pressure of mm. mercury. The steel wool was removed from the product by filtering the bottoms from the distillation step through a steam funnel. A yield of 247 g. of a dark waxy material was obtained. The pour depressing potency of this product was tested by blending 1% by weight of the same in a waxy base oil consisting of 80 parts by weight of a. light parafiinic lubricating oil of the white Pennsylvania type and 20 parts of Pennsylvania, bright stock, the blend having-aviscosity of 5.0 secondssayboltat 210-F. The unblended base stock exhibited a pourj point of +30 F. as determined by the standard ASTM procedure while the blend containing 1% of the additive exhibited a pour point under this procedure of -30 F.

This application is a continuationein-partbf Serial No. 789,576, filed December .3, .1947, for the same inventors which is nowabandoned.

What is claimed is:

1. A process for the formation of a material having the characteristic of lowering the pour point of waxy mineral oils which comprises heating stearic acid at a temperature of from500".;F.

5 ing is about 6 hours.

EUGENE LIEBER. ALOYSIUS F. CASHIMAN.

REFERENCES CITED The following references are of record in the 'file'of this patent:

"UNITED STATES PATENTS Number Name Date 15 2,201,767 Franceway May 21, 1940 2,256,353 Rheineck et a1. Sept. 16, 1941 2,349,165 Grant May 16, 1944 2,373,015 Cowan et al. Apr. 3, 1945

Claims (1)

1. A PROCESS FOR THE FORMATION OF A MATERIAL HAVING THE CHARACTERISTIC OF LOWERING THE POUR POINT OF WAXY MINERAL OILS WHICH COMPRISES HEATING STEARIC ACID AT A TEMPERATURE OF FROM 500* F. TO 700* F. FOR A PERIOD OF FROM 4 TO 10 HOURS IN THE PRESENCE OF STEEL WOOL.