US2344016A - Corrosion-preventive hydrocarbon oil - Google Patents

Description

2,344,016 CORROSION-PREVENTIVE HYDROCARBON OIL Alvin P. Anderson, Berkeley,

Qompany,

Shell Development Calm, assignor to San Francisco,

Calif., a corporation of Delaware No Drawing. Application March 25, 1942, Serial No. 436,155

Claims.

ting power of the oil for the metal at these temperatures may. be highly important. Tests have been developed for measuring the critical adhesion temperatures of oils for metals, which tests show that a wide variety exists between the critical adhesion temperatures of different types of oils.

It is a purpose of this invention to produce a lubricating oil which has a high critical adhesion temperature. It is another purpose to produce an oil which not only does not withdraw from metals at high temperatures, but on the contrary, tends to spread over them in spite of the high temperature. Another purpose is to produce ,oils which have powerful anti-corrosive properties and which can be used for coating freshly machined metal parts to prevent their being attacked by moisture.

I have discovered that the addition of a substance which I call wax amine and which will be described hereinafter in more detail, has the peculiar property of greatly increasing the wetting power of mineral lubricating oils or other refined liquid or solid hydrocarbons to which it is added. This wetting power is greatly enhanced by the further addition of a carboxylic acid having at least 12 carbon atoms. Hydrocarbon oils to which the invention is particularly applicable comprise oils substantially free from asphalts, such as refined mineral lubricating oils or lubricants containing them, such as various greases, e. g., soda, soap greases, calcium soap greases, aluminum soap greases, etc.- Oils used; for dipping metals to prevent their being attacked by moisture or acids in the atmosphere may, if desired, be lighter than lubricating oils and may comprise gas oil, kerosene or naphtha. Other compositions for rust protection may comprise petrolatum, paraffin wax, etc.

The amount of paramn wax to be added to mineral lubricating oils to be effective for my purpose may range from about .25% to 5%, and preferably from around .5% to 2%. Amounts of the carboxylic acids, if added, may range from about .1 to 2%, it being preferred that at least a slight excess of the wax amine over the stoichiometric equivalent of the monocarboxylic acid be present. I

Wax amines of this invention. are reaction products of chlorinated hydrocarbon wax treated with ammonia under conditions to cause ammonolysis. Following is a description of the process by which they are manufactured:

A parafiin wax or petrolatum is chlorinated by bubbling chlorine through it, preferably at a temperature between and C. until a chlorine content above at least 20% and preferably 25%- 38% by weight is reached. The chlorinated wax is dissolved in a suitable solvent, such as absolute ethyl alcohol, and ammonia is added thereto in suflicient quantity, e. g., 8%-l0% by weight. The mixture is heated in an autoclave to a temperature of the order of -175 C. which produces a pressure of about 300-500 lbs. until ammonolysis is substantially completed, which may require, for example, 6 hours. The ammonium chloride, solvent and excess ammonia are then separated by filtration and distillation.-

Wax amines prepared under the above preferred conditions have more pronounced metal-wetting properties than wax amines prepared under different conditions.

The composition and properties of wax amines vary in general within the following normal range:

They are'translucent viscous liquids of amber to brown color having an average molecular weight of 450-600; bromine number below 100, usually 25-100 (gms. Br/100 gm); a nitrogen content of 3%6%, of which about 10%-50% is tertiary and the remainder primary or secondary amines. A typical sample of wax amin had an average molecular weight of 505, bromine number of 60, contained 5.50% nitrogen, of which 69% was in the form of primary or secondary amines and 31 of tertiary amines.

Thus it can be seen that 'wax amine is a mixture of aliphatic amines, containing no apprecia ble proportion of quaternary ammonium compounds. Most paramn chains carry more than one nitro en and are slightly unsaturated. However, the molecules contain no aromatic groups.

Carboxylic acids to be added in addition to the wax amine should have at least 12 carbon atoms and should preferably be saturated, i. e., be free or substantially free from olefinic double bonds.

hesive properties of the oiL Saturated acids in general are less apt to break down through oxidation, and also in general are far more effective in the matter of enhancin the effect of the wax amines. They should preferably be predominantlyaliphatic, i. e., should contain more than half of their carbon atoms in aliphatic formation, inasmuch as the predominantly cyclic acids, and particularly the aromatics, are normally less effective. The acids may be monoor polycarboxylic.

Suitable acids are, for example. lauric, palmitic, stearic, behenic, arachic, phenyl stearic, etc., acids. Other suitable acids may be produced by oxidation of paraffin wax, for example, by blowing air through it at an elevated temperature, if desired, in the presence of an oxidation catalyst. Of the polycarboxylic acids, the alkylated succinic acids and agarlc acids are very suitable. Still other acids are the alkylated' glutaric, adipic, pimelic, suberic, azelaic, sebacic, tricarballylic, wax phthalic, polymerized olelc, etc., acids. Airline, hydroxy, halogen, sulfur, etc.,

derivatives of the above may be used, as, for ex- A ample, hydroxy or amino palmitic or stearic acids, chlorinated or sulfurized fatty or alkyl maleic acids, N-amino bis fatty acids, etc.

In addition to the above compounds, other agents may be added, such as oxidation inhibitors, blooming agents, detergents, etc. The presence of anti-oxidants, such as oxidation inhibitors or retarders is particularly desirable, inasmuch as they will not only protect the mineral lubricating oil from deterioration, but the wax amine as well. may be of the aromatic'hyydroxy or amino type.

Example I The critical adhesion temperature of an oil with and without the wax amine additive was measured asfollows: The critical adhesion temperature apparatus comprises a 1" x 2" bar of cold rolled steel having a trough on one side. The bar is placed in a position of 1 inclination to horizontal with the trough on the upper surface. The bar is then heated at the lower end so as to maintain there a temperature of 400 Two or three dropsof oil to be tested are placed in the trough at a point where the temperature is exactly 400 F3, and the movement of the oil is then noted. The oil then begins to move up against the gravitational force away from the source of heat. If the, oil has good adhesion qualities, it will stop at arelatively short distance from the source of heat. If it has poor adhesion qualities,'it will travel farther. The temperature of the spot at which the oil stops is then noted and recorded as the critical adhesion temperature.

A western mineral lubricating oil S. A. E. 30

was tested by the above test. Its critical adhesion temperature was 150 F. To a sample of this oil was added 1% of the wax amine and 2.5% of a calcium petroluem sulfonate, the latter being a detergent having no influence on the ad- The critical adhesionv temperature rose to 164 F. To another samplewas added 1% wax amine, 5% stearic acid and 2.5% of the calcium petroleum sulfonate. The critical adhesion temperature now rose to 269 F., and the oil spread up the sides. of the trough. leaving a continuous film, thus showin: excellent wetting power.

the atmosphere for three days.

period, they were examined with the following Suitable oxidation inhibitors Example If- Stainless steel balls were coated with doped and undoped S. A. E. 30 lubricating oil. The coated balls were placed in a. water bath main- 5 tained at C. After 64 hours, the balls were examined with the following results:

Exam le In Mild steel plates were coated with doped and undoped S. A. E. 30 lubricating oil. The coated plates were then left undisturbed, exposed to At end of that results:

g Addition agent Condition:l giggstes after None Edges rusted. .5 7 free wax amines Edges somewhat rusted. .5 0 free wax amines-F591, stcaric acidflng No rust.

I claim as my invention:

1. A corrosion-protective composition for metals comprising a. normally non-gaseous hydrocarbon oil substantially free from asphalt and containing dissolved a small amount of a hydrocarbon wax amine substantially free from chlorine which amine is a reaction product of chlorinated paraflin wax and ammonia.

2. The composition of claim 1 wherein said non-gaseous hydrocarbon comprises a. refined lubricating oil.

3. The composition of claim 1 wherein said non-gaseous hydrocarbon is a. petrolatum.

4. A corrosion-protective composition for met-' als comprising a normally non-gaseous hydrocarbon oil substantially free from asphalt and containing dissolved a small amount of a hydrocarbon wax amine substantially free from chlorine having a molecular weight of about 458-660, a nitrogen content of 3%-8% and a bromine number below 100 which amine'is a. reaction product :1 chlorinated paraflln wax and ammonia. I

5. A corrosion-protective composition for metals comprising a normally non-gaseous hydrocar bon oil substantially free from asphalt and containing dissolved .25%-5% of a hydrocarbon wax amine substantially free from chlorine which amine is a reaction product of chlorinated parafin wax and ammonia.

'6. A corrosion-protective composition for metals comprising a normally non-gaseous hydrocarbon oil substantially free from uphalt and containing dissolved .5%-2% of a hydrocarb n we! amine substantially free from chlorine whicl a amine is a. reaction product of chlorinated paraffln-wax and ammonia.

'7. A corrosion-protective composition for met als comprising a. normally non-gaseous hydrocar bon oil substantially nee from asphalt and con taining dissolved small amounts each of hydro acid having at least 12 carbon ems.

'II is saturated.

taining dissolved from .25%-5% of a hydrocar- 10 bon wax amine substantially free from chlorine and from .1%-2% of a predominantly aliphatic saturated carboxylic acid having at least 12 carbon atoms. 13. A corrosion-protective composition for metals comprising a normally non-gaseous hydrocarbon oil substantially freeirom asphalt and containing dissolved from .25%-5% of a hydrocarbon wax amine substantially free from chlorine and from .1 %-2% or a saturated predominantly aliphatic carboxylic acid having at least 12 carbon atoms, the amount of the waxamine being in excess oi the stoichiometric equivalent of said acid.

14. A blended mineral lubricating oil having anti-corrosive properties for metals and a critical adhesion temperature substantially higher than that of said mineral lubricating oil alone, containing dissolved .25%-5% of a hydrocarbon wax amine substantially free from chlorine which amine is a reaction product of chlorinated paraffln wax and ammonia.

15. The composition of claim 7 wherein said acid is a saturated monocarboxylic acid.

ALVIN P. ANDERSON.