DE1010686B - Process for making light colored soaps - Google Patents

Description

GERMAN

The invention is concerned with the manufacture of soaps, in particular the bleaching of soaps with a Alkali hypochlorite.

If a soap of good color is to be made, it is necessary to bleach the oil with a fuller's earth. However, bleaching oils with fuller's earth is a cumbersome and costly process that requires filtration of the oil required from the fuller's earth. It also includes a treatment of the depleted earth in order to to recover the substantial amount of oil left by the bleaching earth during the treatment is adsorbed. As a result, earth bleaching of oils is only used in soap production when when the highest quality soaps, such as toilet soaps, are to be produced.

The bleaching of oils by treatment with chemical bleaching agents followed by saponification to make good colored soaps, or the bleaching of soaps from unbleached oils avoids the disadvantages of bleaching with earth mentioned above. As a chemical bleach the hypochlorites, and especially sodium hypochlorite, have been recommended. Such hypochlorites however, most oils do not bleach effectively, although some oils have some bleaching effect on the very high concentrations of hypochlorite can take place. Hypochlorites have also been used as bleach for Soaps and soap sticks are known. The bleaching achieved in this way, however, is often unsatisfactory.

In soap production, the liquor which separates from the salted out soap has a content of unconsumed alkali which is usually higher in continuous processes than in batch processes, as well as impurities such as contaminants and dyes, which are present in the oil before saponification Method of manufacture
light colored soaps

was.

It is uneconomical to drain this liquor for glycerol recovery without recovering the alkali. The unconsumed alkali in such lye can be neutralized by mixing the lye with an oil which contains free fatty acids. The free fatty acid in this oil neutralizes the alkali to form a neutral oil-soap mixture. This neutral oil-soap mixture, which contains all the dirt from the starting oil, is then treated, for example by centrifugation, in order to remove the greater proportion of the aqueous constituents and the dirt impurities. The oil-soap mixture is then added to the oil which is to be saponified in a continuous saponification process. Although most of the dirt and other contaminants are removed from the oil-soap mixture before going into the continuous soap making process, some amount of contaminants are not removed and therefore contaminants are steadily being returned to the Seifenher applicant:
Unilever NV, Rotterdam (Netherlands)

Representative: Dr.-Ing. A. van der Werth, patent attorney,
Hamburg-Harburg I ₁ Wilstorfer Str. 32

Claimed priority:
Great Britain 16 February 1954

Norman Albert Hurt, Lymm, Chester (Great Britain), has been named as the inventor

Position process led. For a while there is an advancing one Discoloration in the continuous soap making process with consequent pollution of the soap produced, a state can be achieved in which the soap is treated as those with most known hypochlorite-using methods are unsuccessful in making the soap more satisfactory Way to bleach.

According to the invention, light-colored soaps are made by adding an oil containing free fatty acids treated with a chlorite, then saponified the chlorite-treated oil with alkali and the soap obtained with a Hypochlorite is bleached.

The chlorite can be an alkali chlorite, such as sodium chlorite, and is preferably added to the oil in the form of a added aqueous solution. In the same way, the hypochlorite can be an alkali hypochlorite, e.g. B. a sodium hypochlorite and is added to the soap in the form of an aqueous solution. If desired, can the hypochlorite or the chlorite are formed in situ in the soap or in the oil, for example the Hypochlorite by adding alkali, e.g. B. sodium hydroxide, to the soap and passage of chlorine gas through them.

The method of the invention can be used for bleaching soaps made from any vegetable and animal oil a content of free fatty acids are used,

709 549/421

d. that is, it can be used for soaps rather than unrefined oils which generally contain free acids. It is of particular advantage for decolorizing Soaps made from oil mixtures that contain the acidic oils obtained by splitting soap stick, which latter is obtained from the alkaline refining of crude oils.

Treating the oil with chlorite, saponifying and bleaching the soap with hypochlorite can all in one The crude, mixed, split oils can be hard, acidic oils, e.g. B. hydrogenated, acidic palm oil, whale oil or Be palm kernel oil or mixtures thereof. Soft acidic oils, e.g. B. sour peanut oil, cottonseed oil 5 or corn oil, or mixtures containing some soya oil.

To this mixture, soap stick was added in an amount sufficient to contain 20 parts of fatty acids in the mixture. That amount of soap stick

single boiler, e.g. B. a soap kettle executed io was not sufficient to make the mixture alkaline. Such boilers should preferably make acid-proof, and be the free fatty acid content of the final mixture, because the product of Chloritzusatzes was nichtsäure- 20.6 ° / _0, expressed as oleic acid,
can attack solid material. 100% of this oil mixture were at 80 ° in one with

Any reaction vessel equipped with a stirrer and containing 0.5 part alkali, which is usually used in soap production, can be used for the saponification. Examples 15 len sodium chlorite in the form of an aqueous solution of alkali metal hydroxides can play treated as sodium and about 50 ° / ₀ concentration. Treatment potassium hydroxide, used to make water soluble
To prepare soaps, while alkaline earth hydroxides, e.g. B.
Calcium and barium hydroxide can be used to make water-insoluble soaps.

The oil treated according to the invention can

a

any of those commonly used in soap making. Examples of preferred oils are rapeseed, peanut, Palm, coconut, OHven, palm kernel and the like oils and tallow.

The amount of the chlorite may be between 0.1 and 10 ° / _0, based on the total weight of oil and fatty acid, which are to be reacted with alkali is. The best results are obtained with 0.5% chlorite and continued for 30 minutes, after which it was saponified with caustic soda in the usual manner, after settling and removal of the lower liquor, the soap was washed and the washing water removed. To the soap, which had about 60% total fat content, 15% by weight water and 5% by weight based on the weight of the treated soap (equivalent to about 8.3% by weight of the total fat mass) of sodium hypochlorite liquid with about 14% by weight of available chlorine were added. The mixture was in a glass or of a suitable chemically resistant material existing _r and equipped with a stirrer reaction vessel was heated to 60 °

achieved. The amount of hypochlorite used (14 _{% / 0} chlorine that can be supplied at this temperature for about 15 minutes) is preferably between 0.25 and bleaches. The mixed soap was then in the usual manner 20%, which is about 0.04, made ready expressed to 3 ° / ₀ hypochlorite. Lovibond Color measurements of a 10 ° / ₀ as the alkali metal hypochlorite, based on the total weight of the alcoholic soap solution are in the following treated previously with oil and fatty acid chlorite. Table 1, which also Lovibond measurements The best results gives 7,5 ° / ₀ aqueous hypochlorite. 35 reproduces soaps which are produced by saponifying an

negotiated, a / _0-treated bleaching earth with 5 ° and

The temperature of the chlorite-associated oil and fatty acid should be between 40 and 100 °, preferably 80 °, the contact time between 5 and 300 minutes and preferably 30 minutes when running in batches of the proceedings. Preferably the contact time between the soap and the hypochlorite is kept as short as possible. In one embodiment of the invention which is for use in combination with a continuous soap making process is suitable, a soap stream of chlorite treated and oil containing free fatty acids by means of suitable mixing means with a stream of a aqueous solution of hypochlorite are mixed. Vigorous stirring of the soap and hypochlorite is not necessary. The color of the bleached soap shows less tendency to deteriorate on standing than it does do soaps bleached with hypochlorite alone.

The method of the invention is also particularly suitable for lightening using under liquor manufactured soaps.

The invention will be illustrated by the following examples, now, the Lovibond color unit readings at 10 ° / ₀ aqueous soap solutions in 70volumprozentigem ethyl alcohol in a 2-inch cell were carried out. All parts are by weight.

an oil mixture treated with 10% hypochlorite.

Table 1

Lovibond readings Red Origin of the soap with alcoholic
Soap solutions 2.1 yellow Untreated oil mixture ... 22.0 1.6 Oil mixture treated with 5% fuller's earth 7.0 1.3 Oil mixture treated with 10% hypochlorite 9.0 Treated with 0.5% chlorite Oil followed by a Be 0.3 treatment of soap with 5% Hypochlorite 1.5

The above numbers clearly illustrate the superior bleaching effect of the process of the invention over soap made from 10% hypochlorite or from oils bleached with fuller's earth.

example 1

This example illustrates the treatment of a crude oil blend to which soap stick has been added. An oil mixture of the following composition was made:

Raw palm oil 35 parts

Raw palm kernel oil 35 "

Raw, mixed, split acidic oils 10 "

Example 2

Soaps prepared in the same way according to the last line of the table above were used for 12 and 15 days Maintained 35 ° and 75% relative humidity. Lovibond readings on a 10% alcoholic soap solution of the Samples before and after standing are shown in the following tables, with those in Table 2 relate to a storage time of 12 days and those in Table 3 to a retention time of 15 days.

Table 2

Origin of the soap

Soap before storage,
Soap after 12 days
Retention period

Lo vibond readings

with alcoholic

Soap solutions

Yellow I red

0.9
1.0

0.2 0.2 mixer out and finished in the usual way. The same tests were carried out with untreated oil mixtures, and the results obtained are given in Table 4 below.

Table 4

Tabel 3 Lovibond readings
with alcoholic
Soap solutions
Yellow I red 0.3
0.3 Origin of the soap 1.0
1.1 Soap before storing ..
Soap after 15 days
Retention period

Lovibond readings 5.0 3.3 1.0 Origin of the soap with alcoholic
Soap solutions Yellow I red Untreated oil mixture ... 29.0 Treated with 0.5% chlorite Oil followed by sodium hydroxide and chlorine gas treatment of soap

35

These numbers clearly show the lack of a color change in soaps made according to the invention.

Example 3

This example illustrates the formation of hypochlorite in situ. A blend of oils was prepared from the following Approach:

Raw palm oil 24.0 parts

Raw sebum 22.5 "

Raw palm kernel oil 24.0 "

Raw mixed, soft, sour oil 9.5 "

40

The raw, mixed, soft, sour oil can be peanut acid, cottonseed oil, or corn oil, or something oil blends containing acid soya oil.

To this mixture, soap stick was added in an amount sufficient to result in 20% fatty acids in the mixture. This amount of soap stick was insufficient to make the mixture alkaline and the free fatty acid content of the above oil mixture was 15.1 % in terms of oleic acid.

The oil mixture was made with 0.5% sodium chlorite at 80 ° bleached and saponified in the manner described in Example 1. The soap was then made with about 15% of theirs Weight of the required amount of sodium hydroxide containing water, which, when reacted with chlorine, is the equivalent of about 5% by weight the soap (with 60% total fat content) has sodium hypochlorite liquid with about 14% by weight available Chlorine yields. This mixture was heated to about 60 ° and passed through a suitable closed mixing device, z. B. a centrifugal pump or other suitable pump. The necessary amount of chlorine gas to react with the sodium hydroxide to form the equivalent of about 5% sodium hypochlorite liquid with about 14% available chlorine, based on the soap mixture with a total fat content of 60%, was added to the stream of soap-sodium hydroxide mixture entering the mixer, z. B. into the inlet side of the pump. The bleached soap went steadily from the outlet of the

Example 4

The procedure given in Example 1 was carried out with crude palm oil. The palm oil was 0.5% Treated sodium chlorite in the form of an aqueous solution of about 50% concentration and after saponification the resulting soap is treated with 5% sodium hypochlorite liquid with about 14% available chlorine. Pattern of Soap was drawn from the reaction vessel at the intervals shown in Table 5. The color of the Sample was measured in Lovibond units as described in Example 1. The results are shown in Table 5.

Table 5

time in Lovibond readings in alcoholic yellow Red Seconds Soap solutions 7.0 0.7 2.6 0.2 0 2.4 0.2 10 2.3 0.2 20th 2.1 0.1 30th 2.0 0.1 45 1.8 0.1 60 1.6 0.1 90 1.4 0.1 120 1800

From this table it can be seen that for a soap made from a chlorite-treated oil, 90% of the total bleaching effect of the hypochlorite on the soap is achieved in 60 seconds. This explains the extraordinarily rapid bleaching action exhibited in bleaching the soap as a result of using the present Invention occurs.

Claims (3)

Patent claims: 1. A method for producing light-colored soaps, characterized in that a free fatty acid containing Glyceride oil treated with chlorite, preferably 0.1 to 10% sodium chlorite, then the chlorite treated Saponified oil with alkali and the soap obtained with about 0.04 to about 3% of an alkali hypochlorite, preferably sodium hypochlorite, based on the total weight of the chlorite-treated oil, is bleached. 7 8 2. The method as claimed in claim 1, characterized in that the documents considered: indicates that the temperature at which the handling _ _J , " _J ,, ..._ ,,., ^ ,,". "^ treatment of the oil with chlorite is carried out between 40 ^Deutsche ^ tentschnft No. 843 132; and 100 °. Schrauth, Handbook of Soap Manufacture, 6th edition 3. The method according to any preceding arrival 5 l ^a g ^e · S. 72, 306, 355; spoke, characterized in that the chlorite communications from the electrical engineering works in Munich and / or hypochlorite in situ in the oil and / or the A.G., »Guidelines for the Use of Sodium Soap are formed, chlorite EWM 80% * '> P. 3. © 709 54W421 6.57