DE1443596A1 - Process for the production of glycerol monoesters - Google Patents

Description

Process for the production of G-lycerol monoesters

According to patent (application C 25 830 IVb / 12 o), ethylene

glycol monoester from saturated carboxylic acids, which alone or in Mixture, can be used with each other, with ethylene oxide, optionally in excess, at temperatures between 25 and 200 C, preferably 80 and 160 C, in the absence of catalysts and in Presence of a mixture of water and neutral inorganic alkali salts, such as chlorides and / or nitrates and / or sulfates, in amounts up to 40 wt .- ^, based on the acid used, manufactured.

As saturated mono- and polycarboxylic acids, for example, come aliphatic carboxylic acids with 1 to 22 carbon atoms, benzene carboxylic acids and their substitution products, phthalic acids, benzene tri and tetracarboxylic acids, naphthalic acid and others in question.

The alkali salts to be used should at least have the purity level Possess "pure" and be free of by-products, the catalytic side effects on ethylene oxide, the intermediate products or those according to the invention Exercise end products, for example with regard to condensation or saponification.

The alkali salts used are preferably potassium chloride, potassium sulfate and potassium nitrate.

Instead of the neutral alkali metal salts mentioned, it is possible, if appropriate the corresponding alkaline earth metal salts can also be used, provided they are water-soluble and none in the reaction with the carboxylic acids provide poorly water-soluble salts.

It has now been found that glycerol monoesters can be used

the method according to the patent (application C 25 830 IVb / i2 0)

can be produced if glycide is used instead of ethylene oxide.

- 2 BATH ORIGINAL

80 98 07/0416

In general, the reaction with glycide proceeds under comparable conditions Conditions more slowly than with ethylene oxide. However, this does not result in poorer yields. The speed of reaction can be can be varied by changing the working conditions, for example the temperature can be increased or work can be carried out under pressure. An excess of glycide has the same effect.

The products produced by the process according to the invention can be used because of their high emulsifying power or their easy solubility in water with regard to their isolation. There is but enough known methods with which, experience has shown, the isolation of the glycerol monoester in question can be achieved. Particularly The separation is easy wherever the ester separates oily from the aqueous phase. Mechanical separation is sufficient here combined with possibly repeated washing and drying of the oily layer. Another possibility is the extraction of the reaction mixture with a suitable solvent, such as ether, Benzene o.a. If a particularly high purity of the monoester is desired, the purification can, for example, by recrystallization or Distillation take place.

The products which can be produced by the process according to the invention are Can be used as such or as intermediate products for the manufacture of emulsifiers, plasticizers, resins and lacquers.

example 1

61 g of benzoic acid
250 g of water
60 g glycid, approx. 85 $
6 g of potassium chloride

were combined in a cylindrical glass jar and kept for two hours Stirred at 23 to 25 C. Subsequently, within a further hour brought the temperature to 80 C. After a total of 10 hours

809807/04 1 6

the acid number of the reaction mixture 5 »7 and after a further 4 hours 0.4 · The monoeter can be isolated by ether extraction with the following Key figures

Acid value saponification value Hydroxyl number Boiling points

found » 0.8 285

576/573 151-154 ° C / O, 6 mm

calculated:

286 572

Example 2

72 g n-caprylic acid
250 g of water
15 8 sodium chloride
74 e glycid

were heated ^{to Θ0 0} C within two hours while stirring in a cylindrical vessel. After 1.5 hours the Reaktionsmisohung formed at 70 ° C, a uniform clear solution with an acid number - 26. laughing total of 2 hours, the temperature was 80 ⁰ C and the acid value - 0.7. After a total of 2.5 hours the acid number was -0 and the reaction mixture formed two layers, with the upper layer forming the ester, which contained some water. For the purpose of separating off the water, the oily layer was taken up in ether, mechanically freed from water, washed once, dried and distilled ether-free. The yield was 98 g caprylic-glycerinmonoester - 90 i <> the theory with the following Kennzahlent

Acid number saponification number: Hydroxyl number

found: calculated: 0.2 0 255 256 509 512

The ester forms a colorless liquid,

809807/04 1

BATH ORIGINAL

Bapiel?

86 tS oapriic acid, commercially available. (F * 24 to 26 "'C, 2 ^ 0 g water
74 S Slycid (approx. 35 followings)

were stirred in a cylindrical vessel within 2 stalls to 30 "0 c-rhitst. 2io Änfanga acid number of the milky-cloudy Misshuag was 6? and after S hours 64.

In parallel with the above experiment only using 12g sodium chloride -om ^ de nacl * 2 hours a reaction product with a .0 Acid number τοη 0.1 obtained. Working up the reaction mixture and isolation .iss capric acid glyoerinmonoesters can according to "known Methods are done. For example, the monoester can be separated off by cooling the reaction film to below 15 G Cake can be washed one or more times with water. Residual water can be distilled off with or without a vacuum. Of the Monoester can be extracted from the aqueous reaction mixture with ether or separated in hot oil.

Ss were 86.3 i <> theory capric glyeerinmonoester be isolated with the following characteristics?

found; calculated:

Acid number 0.8 0

Saponification number: 236 228

Hydroxyl number: 461,456

Melting point: 31 to 32 ° C

The deviations of the key figures found from the calculated values is based on inconsistencies in the source material.

- 5 -

BATH ORIGINAL 809807/041 G

Example 4

47 »3 β stearic acid, commercially available, F 250 g water 5 g sodium chloride

1443598

49. 54

were heated to 80 ° C. in a cylindrical glass vessel with stirring and 25 g of glycide, approx. 85%, were added dropwise over the course of 30 minutes. The temperature was increased to 90 ° C. over a further hour. After a total of 3 hours, the acid number of the reaction mixture was 0.2 compared to 28 at the beginning. The reaction mixture was stirred with twice the length M ⁿ of acetone and heated until a clear solution, filtered, left to crystallize, filtered off at 10 C and the Krietallisat dried. The yield was 48 g »80% of the theory of glycerol stearic acid monoester with the following key figures:

Acid number »saponification number: Hydroxyl number: melting point:

found:

0.9 151
312
71 to 72.2 ⁰ C

calculated 1

157 314

If the filtrates are used further, the yield can be increased even further will. Since the stearic acid used was not absolutely pure and uniform, but a technical product, there are differences between the found and calculated key figures.

BATH ORIGINAL

80980 7/0416

Claims (6)

1443696 • Claim Process for the production of monoesters by reacting saturated carboxylic acids, which are used alone or in a mixture with one another *! can, with ethylene oxide, optionally in excess, at fempere. «Doors between 25 and 200 C _5, preferably 80 and 160 G, in the absence of catalysts and in the presence of a mixture of water and neutral inorganic alkali salts in amounts of up to 40 wt. - ^, based on the acid used, according to patent '..... »., (Application C 25 830 IVb / i2 o) _s characterized in that glycide is used instead of ethylene oxide, Pat.-Dept. Schu / RS May 6, 1963 BATH ORIGINAL 809807/0416