US2588326A - Manufacture of block grease - Google Patents

Description

Patented Mar. 4, 1952 MANUFACTURE BLOCK GREASE Albert E. Ogden, Franklin, Pa., Richard A. Butcosk, Jackson Heights, N. Y., and Raymond C. Williams, Franklin, Pa., assignors to Socony- Vacuum Oil Company, IneorporatedNew York, N. Y., a corporation of New York No Drawing. Application July 28, 1949, SerialNo. 107,378

4 Claims.

This invention relates to the manufacture of block greases and is concerned with addition of a small amount of a surface active material to the grease batch which results in great reductions in the losses normally incident to the manufacture of block greases due to rejection of portions of the batch.

The block greases are a group of hard greases having high penetration values used in the form of firm blocks for lubrication of high temperature bearings such as those on rotary kilns used in cement manufacture, paper mill dryer rolls, textile calender rolls and the like. The structure of these greases has a very significant bearing on the rate of consumption in use and good block greases are characterized by the presence of small pockets of oil in the grease and freedom from inclusion of pockets of air or other gas.

The block greases are typically high soap content anhydrous greases containing about 20 per cent or more of soap and as small a water content as can be obtained without overcooking, say less than about 1 per cent. These greases are prepared by cooking together suitable ingredients and raising the temperature of the batch suificiently high to dehydrate and then pouring the grease into pans about 6 inches deep and allowing the grease to cool in the pans. In a typical operation the pans are about 4 inches wide, 6 inches deep and 46 inches long.

Conventional block greases have the manufacturing disadvantage of tending to bread loaf in the cooling pans. The term applied to this disadvantage is peculiarly descriptive in that the grease in. the cooling pan will acquire a hard upper crust due to cooling and the crust will then rise up and crack in a manner strongly reminiscent of old fashioned home baked bread. That portion of the block lying under the raised and broken crust is found to be highly porous and this porosity may extend to a considerable depth of the grease in the pan. Grease of this nature is unsuitable for the desired use and must be cut off and rejected. In extreme cases the rate of rejection due to bread loafing and related phenomena may run as high as 60 per cent of the batch.

Although the rejected grease can be added to a subsequent batch and reworked, rejection represents a serious economic loss because of the high cost for labor and utilities involved in breaking up the rejected grease, supplying it to the kettle, heating it and maintaining it at cooking temperature for the required period of time and again pouring it into pans by the use of hand ladles.

A'further source of loss in this type of operation is that the capacity of the expensive kettles representing substantial capital investment is greatly reduced.

It has been found that a number of materials tend to reduce bread loafing but all of them known prior to this invention also have the efiect of altering the structure of the. grease: in such manner that it had to be rejected as unsuitable. For example, glycerol may be added in amounts large enough to inhibit bread loafing, but the desired structure of oil pockets is lost when glycerol is included in such amounts and the grease must therefore be rejected. The problem involved is unusual and is peculiar to block greases, that is the greases which are relatively high in soap content, anhydrous and are cooled by pouring into pans. It might be thought olfhand that a defoamant would inhibit bread loafing but it is found that the outstanding oil defoamant, namely polymerized dimethyl silicone, is ineffective for this purpose. onstrated that dimethyl silicone polymer is not capable of suppressing the tendency to breadloaf. Batches of double size, otherwise corresponding to Example I, were prepared with dimethyl silicone polymer to suppress foaming during cooking in the kettle. This additive was successful for that purpose, thus permitting larger batches, but bread-dealing, batch uniformity and yield were the same with and without silicone polymer. The latter does not affect the characterizing ingredient of this invention, which acts the same regardless of presence or absence of the silicone.

According to the present invention, bread loafing of block greases is inhibited while retaining the. desired structure. of the grease by adding to the batch a small amount, less than about 1 per cent by weight, of an oxygen containing surface active organic compound of specified nature. The

compounds effective for the present purpose are the monoand di-esters of dibasic carboxylic acids with aliphatic alcohols. Typical compounds Within the scope of the invention are di-isobutyl adipate, di-Z-ethyl-hexyl sebacate, di-isobutyl sebacate, di-butyl phthalate, mono-2-ethyl hexyl adipate and similar compounds.

Example I This example represents manufacture of a typical commercial block grease withoututilizing the principles .of thisinvention and is supplied for purposes of comparison to subsequent ex amples showing: the benefits of the invention.

It has been dem- A thousand pound batch was prepared containing the following ingredients:

' Weight percent Tallow 5.00

Hydrogenated fish oil 22.45 Caustic soda 5.40 Glycerine 0.55 Mineral oil 66.60

A thousand gallon kettle is charged with all of the hydrogenated fish oil, tallow and mineral oil. This mixture is then heated to 250 F. by fire on the outside of the kettle. A portion about of the'alkali is mixed with an equal weight of water and heated to 200 F. and added to the hot contents of the kettle. About minutes later the remainder of the caustic soda is added to the kettle as a 50 per cent by weight solution in water heated to about the same temperature as the kettle contents. After addition of the caustic soda, dehydration of the grease iscarried on as rapidly as possible by heating to 500 F. and maintaining that temperature until foam has subsided. The grease is then tapped from the bottom of the kettle into hand ladles from which it is poured into pans about 4 x 6 x 46 inches. The pans are allowed to cool in the air, and the grease is then trimmed and packed for shipping. In a typical commercial run the bread loafing in the first pans to be poured is extremely great, declining with successive pans and being practicably unnoticeable in the last pans to be poured. Much of the grease is of poor structure and it is found that uniformity of the grease throughout the batch is highly unsatisfactory. Typically, upwards of 50 per cent of the batch must be rejected, with the rate of rejection being as high as 60 per cent by weight for some batches.

Ezrample II Example III The batch of grease was similar to that of Example II except that di-Z-ethyl-hexyl sebacate was used in an amount of 0.1 weight per cent. Slightly greater tendency to bread loaf was found in the first pans poured with no bread loafing in the last pans. Structure of the grease was satisfactory and marked improvements over the blank run of Example I were found in yield and uniformity. The yield was 65 weight per cent,

Example IV The additive used in this batch was 0.05 weight per cent of di-isobutyl adipate. Marked improvement over the results of Example I were observed in bread loafing, structure and uniformity. The yield was '70 weight per cent.

Example V In this case 0.1 weight per cent of di-isobutyl' adipate was included in the batch. Still further improvement over Example I was observed with, structure and uniformity at satisfactory. levels.

and only very slight bread loafing. The yield was weight per cent.

Example VI Di-butyl phthalate in an amount of 0.1 weight per cent was used in the grease of Example I. Bread loafing was noticeably decreased and satisfactory structure was obtained. While this additive is of appreciable benefit, it is not as effective as the materials used in Examples II to V, inclusive, at this concentration. The yield was 60 weight per cent.

Example VII Di-amyl sebacate is also effective but, like dibutyl phthalate it does not give as satisfactory results as the other additive discussed. At a concentration of 0.1 weight per cent, bread loafing was appreciably reduced and satisfactory grease structure obtained. The yield was 60 weight per cent.

Example VIII At a concentration of 0.1 weight per cent, di-Z-ethyl-hexyl adipate also appreciably reduces bread loafing and gives satisfactory grease structure. Here again the increased yield, namely 60 per cent, is not as good as that obtained with the most effective of the additives discussed.

Example IX Mono-2-ethyl-hexyl adipate gives intermediate improvement at 0.1 Weight per cent concentration. There was some bread loafing in the first pans but none in the last and grease structure was satisfactory. Uniformity was improved and a yield of 60 weight per cent obtained.

Example X This example relates to a different type of block grease prepared from the following constituents:

Weight per cent.

Mineral oil 67.75 Tallow 12.50 Hydrogenated fish oil 12.50 Caustic soda 4.75 Calcium tallow soap 2.50

The kettle is charged with 80 per cent of the mineral oil together with all of the tallow and hydrogenated fish oil and a 50 per cent water solution of the caustic soda. The mixture is heated to approximately 300 F. and the calcium tallow soap added. Dehydration is then carried out as rapidly as possible to 350 F. at which time the remainder of the oil is added. The grease isthen heated to 470 F. at which time it is drawn into pans of the type described above and allowed to cool before cutting and packing. The tendency to bread loafing and poor structure is not as great as that of the grease described in Example I but it still represents a serious economic consideration. The advantages of this invention are shown by comparison of yields when making the grease described as compared with the same grease containing 0.1 Weight per cent of di-Z-ethyl-hexyl sebacate. The yields are 65-70 weight per cent for the straight grease and 70-75 weight per cent for the grease containing di-Z-ethyl-hexyl sebacate.

We claim:

I. In a process for cooking a mineral lubricating oil fraction with materials selected from the group consisting of (1) fatty acid soaps and (2) fatty acids together with saponifying com-'v pounds to manufacture a. block-grease contain-1 ing, as the predominating constituents thereof, mineral lubricating oil and a fatty acid soap, the improvement which comprises including in the cooking batch a small amount, less than about 1 per cent by weight, of an ester of a dibasic carboxylic acid with an aliphatic alcohol.

2. In a process for cooking a mineral lubricating oil fraction with materials selected from the group consisting of (1) fatty acid soaps and (2) fatty acids together with saponifying compound to manufacture a block grease containing, as the predominating constituents thereof, mineral lubricating oil and a fatty acid soap, the improvement which comp-rises including in the cooking batch a small amount, less than about 1 per cent by weight, of di-isobutyl adipate.

3. In a process for cooking a mineral lubricating oil fraction with materials selected from the group consisting of (1) fatty acid soaps and (2) fatty acids together with saponifying compounds to manufacture a block grease containing, as the predominating constituents thereof, mineral lubricating oil and a fatty acid soap, the improvement which comprises including in the cooking batch a small amount, less than about 1 per cent by weight, of di-Z-ethyl-hexyl sebacate.

4. In a process for cooking a mineral lubricating oil fraction with materials selected from the group consisting of (1) fatty acid soaps and (2) fatty acids together with saponifying compounds to manufacture a block grease containing, as the predomintaing constituents thereof, mineral lubricating oil and a fatty acid soap, the improvement which comprises including in the cooking batch a small amount, less than about 1 per cent by weight, of mono-Z-ethylhexyl adipate.

ALBERT B. OGDEN. RICHARD A. BUTCOSK. RAYMOND C. WILLIAMS.

REFERENCES CITED UNITED STATES PATENTS Name Date Morway Dec. 13, 1949 Number

Claims (1)

1. IN A PROCESS FOR COOKING A MINERAL LUBIRCATING OIL FRACTION WITH MATERIALS SELECTED FROM THE GROUP CONSISTING OF (1) FATTY ACID SOAPS AND (2) FATTY ACIDS TOGETHER WITH SAPONIFYING COMPOUNDS TO MANUFACTURE A BLOCK GRESE CONTAINING, AS THE PREDOMINATING CONSTITUENTS THEREOF,, MINERAL LUBRICATING OIL AND A FATTY ACID SOAP, THE IMPROVEMENT WHICH COMPRISES INCLUDING IN THE COOKING BATCH A SMALL AMOUNT, LESS THAN ABOUT 1 PER CENT BY WEIGHT, OF AN ESTER OF A DIBASIC CARBOXYLIC ACID WITH AN ALIPHATIC ALCOHOL.