NO128776B - - Google Patents

Description

Process for the preparation of a salt or a mixture of salts of mono-(alkyl-polyethoxy) sulfates which are liquid under normal temperature and

pressure ratio.

Acid sulfates corresponding to the formula

R(OCH2CH2)nOS02OH

where n has an average value of 2-3 and R

means alkyl groups with 8-16 carbon atoms, are known. One can produce them

e.g. while condensing lauryl alcohol

with epoxyethane and sulfates the obtained

product. Where R is dodecyl, one goes for

mostly based on technical lauryl alcohol and

uses the epoxyethane in an amount, which

corresponds to the desired average number of ethoxy groups. In general, you therefore get mixtures in which approximately 75% of the alkyl groups are

dodecyl groups, while the value for n can

differ quite strongly for the individual

compounds in the mixture. Upon neutralization with sodium hydroxide, these compounds give neutral salts with very good

surfactant effect. See above Soap,

Perfumery & Cosmetics, December 1956, p

1367 and Soap and Chemical Specialties,

August 1956, page 45.

It appears from these two publications

that sodium lauryl sulfate, where n = 0,

is a solid and that at increasing values

of n the consistency changes little by little

over pasty until liquid. In practice

one preferably uses no compounds of the above-mentioned type, in which n has

a greater mean value than 3, because it

surfactant action no longer increases

above this value, while the cost price

becomes higher. If n has an average value of 3, the sodium salts are still pasty.

In practice, surface-active substances with a paste-like consistency are not good for sale in an anhydrous state, as the paste is relatively difficult and can never be completely removed from the containers. The commercial form of these substances is also generally an approximately 30% solution. However, this means a strong increase in transport costs, while such solutions are also not usable for anhydrous application purposes, e.g. when you want to use the surfactants as an emulsifier in anhydrous insecticidal mixtures.

In the second of the two above-mentioned publications, it is further mentioned that other types of these compounds among the triethanolamine salt have also already been prepared. Nothing is mentioned about the consistency in the anhydrous state. From experiments, however, it can be seen that at values for n from 2-3, the triethanolamine salt in the anhydrous state is likewise pasty.

It was now found that new salts can be obtained from the compound with the formula

in which n has an average value of 2-3 and R are alkyl groups with 8-16 carbon atoms, R however in the majority of possibly all compounds in the mixture meaning dodecyl, which salts are liquid under normal temperature and pressure conditions, neutralizing this compound or mixture of compounds with diethylamine, isopropylamine and/or butylethanolamine.

The neutralization can be carried out by adding the amines to the acid sulphates or

facing. The two former amines are tem-

volatile so that losses can occur due to its evaporation from the surface during the occurring reaction

heat. In such cases, it is preferable to in-

pass the amine below the surface of the acid sulfate. Naturally, it is appropriate to

stirring during the neutralization. Optionally, one can work with a return cooler, while if desired, the neutralization can be carried out in a closed system under pressure.

The neutralization preferably takes place

at a somewhat elevated temperature, e.g. at 30° C, due to the fact that the viscosity of the

is then lower, which facilitates discussion

the ring.

The required amount of amine can be easily determined by simple experiments beforehand or during the neutralization. Because you start from strongly acidic products and the an-

reversed amines are not strong bases, this amount always amounts to more than the equivalent weight.

One can start both from the pure mono-(dodecyl-polyethoxy)-sulfates and from the

corresponding acid sulfates which are prepared from technical dodecyl alcohol which is preferred for economic reasons. Likewise, it is mu-

first to isolate di- or triethoxyforbin-

the part and then apply the procedure

ten according to the invention, but this also naturally entails an increase in costs. Naturally, one can also an-

reverse mixtures of the aforementioned amines.

The new products have in aqueous solution

ning the same surfactant properties as the corresponding sodium salts, but also have the advantage that they are liquid in the anhydrous state. This enables them to be delivered undiluted to consumers, whic-

ket means a considerable saving in transport costs. They dissolve well in water, as the dissolution rate naturally

can obviously be increased by heating. dissolve-

however, the reaction also takes place quickly at room temperature when the most diverse compounds are added, e.g. alcohol,

glycols and salts. The products according to the invention are dissolved, e.g. at room temperature

ture well in a 1% sodium bicarbonate solution.

The fact that the products according to the invention are liquid in an anhydrous state also makes them suitable for a number of

dre applications. Thus, they can be used e.g. such as shampoo, in that they are diluted with warm water on the skin.

This makes it possible to bring the new products

in the trade in small capsules or similar that contain approximately the dose that is

necessary for a hair wash. Furthermore, in contrast to the corresponding sodium sal-

can also be used as emulsifiers in anhydrous systems, e.g. in anhydrous insecticide preparations.

As already mentioned, by an-

turning triethanolamine into a pasty product. This is also the case when

reversal of e.g. monoethanolamine and ethyl ethanolamine. It is therefore surprising that by using the three amines mentioned above, liquid neutralization products are obtained

ter.

The products according to the invention dissolve

sees clearly up to 25% paraffin oil.

Example I:

The starting point is 100 g of an acid sulphate

which was prepared by condensing technical lauryl alcohol with 2.2 mol of epoxy

ethane and then sulfates. During the re-

under the surface, pores were added

tionwise diethylamine, the temperature during cooling being kept at 30° C. After the equivalent amount of amine had been added, the neutralization reaction was continued, regularly preparing a concentrated aqueous solution from small samples of the reaction mixture and determining the pH value.

In this way, so much was added

amine until the pH value in the aqueous

solution amounted to approximately 7. A total of 27.2 g of diethylamine was added.

In the same way, 100 g of the above

standing acid sulfate neutralized with 34.5

g isopropylamine. The products obtained are clear, viscous liquids.

Example II:

An acid sulfate was produced on it

in the manner described in example I with the pre-

shell that 2.8 mol of epoxyethane was used instead of 2.2 mol. 100 g of this sour sul-

butylethanolamine was added in portions while stirring, allowing the amine to drip onto the surface of the acidic sulfate,

while the temperature was kept at 30°C.

After the equivalent amount of amine was

added, the pH course was followed on that in ek-

sample In the manner described. It turned out that a total of 38.5 g of butylethanolamine was required for the neutralization.

You get a clear, viscous liquid.

Claims (3)

1. Process for the preparation of a salt or a mixture of salts of compounds with the formula where n has an average value of 2-3, R means alkyl groups with 8-16 carbon atoms, with R however in the majority of the compounds in the mixture possibly in all the compounds, meaning dodecyl, which salts are liquid under normal temperature and pressure conditions, characterized by neutralizing this compound or the mixture of compounds with diethylamine, isopropylamine or butylethanolamine. 2. Method according to claim 1, characterized in that the neutralization is carried out by introducing the amines below the surface of the acidic sulphate. 3. Process according to claim 1 or 2, characterized in that one starts from compounds in which approximately 75% of the alkyl groups are dodecyl groups.