US2234935A - Vegetable wax - Google Patents

Description

' many special uses.

Patented Mar. 11, 1941 UNITED STATES PATENT OFFICE.

VEGETABLE (AX No Drawing. Application April 26, 1940, Serial No. 331,806

6 Claims.

This invention relates to a process for manufacturing wax and deals, more specifically, with a process for manufacturing a vegetable wax of satisfactory lightness of color from crude vegetable wax powder.

Many vegetable waxes such as carnauba wax, esparto grass wax, sugar cane wax and ouricury wax are obtained from the plants by means of mechanically removing the wax from the plant leaves and/or stems. The powder so obtained is herein referred to as crude wax powder and is composed of small particles of pure wax together with particles of vegetable matter of like size.

A brief description of the manufacture of carnauba wax from its crude powder will illustrate the methods heretofore employed in processing a crude wax powder to obtain the raw material wax. The carnauba wax powder is obtained by thoroughly beating the dried carnauba palm leaves. This powder contains leafy material and other non-waxy matter which may equal as much as 20% of the total mass of the powder. The wax is separated from the leafy material and other non-waxy matter by heating the powder in pots over an open fire to a temperature above the melting point of the wax and crudely straining the molten mass through a cloth. The molten wax filtrate, upon cooling, forms the dark green, brown or brownish black raw material carnauba wax of commerce. The term raw material wax refers to the wax cakes obtained after the first melting of the wax powder.

The untreated dark colored wax is not suited for many of the commercial uses of this wax without subjecting it to costly bleaching treatments. Many such bleaching treatments have been proposed and they may be classified generally as those employing adsorbents; those employing oxidizing and reducing agents, and those which combine both adsorbents and the chemical agents. While the bleaching with adsorbents, such as adsorbent clay or carbon, is satisfactory for many commercial purposes, it does not produce a wax of sufficient lightness of color for The bleaching methods which employ chemicals as bleaching agents often provide a wax product of satisfactory lightness of color, but the chemical action required therefor also alters the structural and chemical nature of the original wax to an extent which interferes with those uses of the wax which depend on the chemical and structural characteristics of the original wax.

It is therefore an important object of this invention to provide a process for manufacturing a of the raw material wax cakes.

raw material vegetable wax from its crude powder which is of satisfactory lightness of color for all commercial purposes. Another object of this invention is to provide a process for manufacturing a wax from vegetable wax powder which is of satisfactory lightness of color and contains the chemically and structurally unaltered components of the original wax. A further object of this invention is to provide an economical process for manufacturing a light-colored wax from crude vegetable wax powder.

Raw material wax as heretofore produced contains appreciable quantities of resinous matter which is highl undesirable in many of the commercial uses of the wax. This resinous or gummy matter cannot be satisfactorily removed according to the bleaching treatments or commercial purification processes heretofore proposed. It is therefore a further object of this invention to provide a process for manufacturing raw material wax from vegetable wax powder which produces a wax substantially resin free. Other objects will readily appear from the description of the invention hereinafter set forth.

It has heretofore been thought that the dark coloration of the raw material wax cakes obtained from vegetable wax powder was inherent within the components of the wax itself. We have discovered that the pure wax particles in the wax powder will form a light colored wax when mechanically separated from the non-wax matter under a microscope. We discovered further that the undesirable deep coloration of the raw material is introduced into the wax by virtue of the melting of the wax in the presence of the leafy material and other non-waxy matter. Part of the coloration is obtained from sources other than leafy matter, such as sand, clay, dirt and humus material, but this coloration can readily be satisfactorily removed from the wax cake by means of subsequent remeltin and filtration. The leafy matter, however, contains diiiicultly removable high coloring substances, such as chlorophyll and xanthophyll, which, together with their decomposition products and the decomposition products of other color-forming substances, are extracted by the hot molten wax to form the greater part of the undesirable deep coloration This coloration is thereby so thoroughly incorporated within the wax that its subsequent complete removal has not been attained by any known process whereby the product produced retains the components of the original wax unchanged.

Contrary to the teachings of the art, we have discovered a process whereby a light colored wax is obtained from wax powder without bleaching the wax. Our process comprises the removal of the coloring and color-forming substances from the wax powder composed of wax and leafy particles, prior to the separation of the wax from the non-waxy matter. This removal of coloring substances is accomplished by means of suitable solvents. Any solvent which readily dissolves chlorophyll, xanthophyll and like substances found in dried leaf tissue, but which does not dissolve appreciable quantities of wax, may be employed in our process. We find that the oxygenated solvents are best suited for this purpose, such as alcohols, ketones, esters and ethers, and that ethyl alcohol is the preferred solvent.

As the first step of our process, the wax powder is placed in the kettle and the cold solvent is added thereto. The amount of solvent employed depends on the type of wax powder, the percentage of leafy matter in such powder, and the quality of wax desired. We found that with carnauba wax powder, a good quality wax is obtained when using about five parts of ethyl alcohol to one part of powder and steeping the powder and solvent for about 12 hours. An exceptionally fine quality wax is produced with the same powder when using about 20 parts of solvent to one part of powder and steeping for a period of about 48 hours. We found that it was preferable to add the solvent in half, quarter or lesser portions and allow each such portion to steep for a period of from 6 to 48 hours. In adding the solvent in two or more steps, each portion of solvent is removed before adding more solvent.

After the final removal of the solvent from the powder by filtration or other suitable means, the filter cake, composed of wax particles and finely decolorized leafy particles, is treated further to remove all possible solvent therefrom. Mechanical presses may be employed for this purpose, but the best results are obtained by blowing air through the filter cake. The filter cake is then placed in a still and heated to a temperature sufiicient to melt the wax and drive off substantially all of the remaining solvent. The molten mixture is filtered to remove the leafy and other non-waxy matter and the molten wax filtrate, upon cooling, forms wax cakes of satisfactory lightness of color.

Certain uses of vegetable waxes demand a product of very light color free from resinous matter and all traces of the steeping solvent employed in the manufacture or bleaching of wax cakes. It has been found that the addition of a suitable adsorbent to the wax powder filter cake, such as adsorbent clays or carbons, prior to the heating and distillation step in the above process, effectively removes the resinous matter and the last traces of solvent and thereby provides a wax product of exceptional purity and lightness of color. The adsorbent serves the further purpose of facilitaing the large scale filtration of the molten wax in the presence of finely divided leafy material.

The following procedure is given as an example of our process:

100 grams of carnauba wax powder was placed in a beaker with 500 c. c. of cold ethyl alcohol and allowed to steep for six hours. The alcohol was then drawn off and another like portion was added to the powder and steeped for another six hours. The slurry of alcohol and powder was filtered and the filter cake pressed to remove all possible solvent. The filter cake was then placed in a still together with grams of adsorbent clay and heated sufiiciently to melt the wax and drive off the residual alcohol. The molten. residue in the still was filtered to remove the adsorbent and other non-waxy matter, and the molten wax filtrate, upon cooling, solidified to form wax cakes of satisfactory lightness of color.

Although the application of our process has been set forth with reference to carnauba wax powder, no limitation is thereby imposed on the process in that it is applicable generally to the manufacture of all vegetable waxes which are obtained from the plants in the form of a powder.

As many apparently widely different embodiments of this invention may be made without departing from the spirit or scope thereof, it is understood that we do not limit ourselves to the specific embodiment thereof except as defined in the appended claims.

We claim:

1. The method of manufacturing raw material wax cakes from vegetable wax powder which comprises steeping the wax powder in a solvent capable of dissolving chlorophyl, removing the solvent from the wax powder, heating the powder to a temperature above the melting point of the wax, filtering the resulting molten mass to remove the leafy material and cooling the filtrate.

2. The method of manufacturing raw material wax cakes from vegetable wax powder which comprises steeping the wax powder in a solvent capable of dissolving chlorophyl, removing the solvent from the wax powder, adding a suitableadsorbent thereto, heating to a temperature above the melting point of the wax, filtering and cool ing the filtrate.

3. In the art of manufacturing solid wax cakes from vegetable wax powder, the step which comprises steeping the vegetable wax powder in a solvent capable of dissolving chlorophyl and removing such solvent from the wax powder prior to the initial melting of the wax.

4. The method of manufacturing raw material carnauba wax from the carnauba wax powder which comprises steeping the wax powder in a solvent capable of dissolving chlorophyl, removing the solvent from the wax powder, heating the powder to a temperature above the melting point of the wax, filtering the resulting molten mass to remove the leafy material and cooling the filtrate.

5. The method of manufacturing raw material carnauba wax from carnauba wax powder which comprises steeping the wax powder in a solvent capable of dissolving chlorophyl, removing the solvent from the wax powder, adding a suitable adsorbent thereto, heating to a temperature above the melting point of the wax, filtering and cooling the filtrate.

6. In the art of manufacturing raw material carnauba wax, the step which comprises steeping the carnauba wax powder in a solvent capable of dissolving chlorophyl and removing such solvent prior to the initial melting of the wax.

JOHN VERNON STEINLE. ELBERT S. MCLOUD.