DE1149907B - Process for the production of higher molecular weight alcohols which contain the grouping -CH-CH-O- - Google Patents

Description

INTERNAT. KL. C 08 g

GERMAN

PATENT OFFICE

B52238IVd / 39c

REGISTRATION DAY:

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL:

FEBRUARY 25, 1959

June 6, 1963

It is known that by reacting ethylene oxide with ethylene glycol or lower polyethylene glycols produce higher molecular weight polyethylene glycols in the presence of an alkaline catalyst can. These products are not uniform, but are made up of higher and lower molecular weight Connections together. This is called the molecular weight of such a mixture average resulting from the molecular weights and the proportions of the individual compounds Molecular weight. Its size depends on the amount of ethylene oxide used.

A disadvantage of the above-mentioned process is that the reaction products, depending on the degree of purity of the ethylene oxide reacted, are more or less dark in color, and generally even have an extremely dark brown appearance. Although you can change the color by treatment with strong bleaching agents such as sodium hypochlorite or hydrogen peroxide, usually at ^zo temperatures above 100 ⁰ C, improve, however, often achieved even by any colorless products, but only a faint illumination. Apart from the undesired color, another disadvantage of the polyethylene glycols after-treated in the manner described is that considerable amounts of undesired by-products, such as organic peroxides, are often formed which cannot be removed or can only be removed with considerable effort affect the cosmetic industry.

From US Pat. No. 1,970,578 it is known that ethylene glycols have a relatively low Excess of ethylene oxide to higher polyethylene glycols can be implemented. You can work in the absence of a catalyst or but use an acidic catalyst. However, this method is not suitable for production of colorless, higher molecular weight polyethylene glycols, for example with molecular weights from 400 to 4000.

It is from the published documents of the patent 974767 (patent application U 2915 IVb / 12o) known that polyglycol ethers of higher alcohols are obtained if higher, saturated, aliphatic, monohydric alcohols first in an acidic medium and then in an alkaline medium with ethylene oxide implements.

The advantage of such a two-step procedure is that one products with more uniform Molecular weight distribution obtained.

The invention, however, was not apparent that one in the implementation of ethylene glycol or Method of manufacture

of higher molecular weight alcohols,

which contain the grouping -CH ₂ -CH _{2 -O-}

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. August Spaeth, Ludwigshafen / Rhein-Oggersheim, has been named as the inventor

low molecular weight polyethylene glycols first in acidic and then in alkaline medium, im In contrast to the known procedure using only alkaline catalysts, can produce colorless to slightly colored polyethylene glycols.

A two-stage process is also described in US Pat. No. 2,674,619. In doing so, however Glycol reacted with propylene oxide in the first stage and with ethylene oxide in the second stage.

An indication of the possibility of colorless polyethylene glycols in a two-stage reaction Implementation of glycols or low molecular weight polyethylene glycols with ethylene oxide alone, could not be found in the patent specification.

It has now been found that higher molecular weight, colorless to pale colored alcohols containing the —CH ₂ —CH ₂ —O— grouping with molecular weights of 400 "to 4000 can be obtained by reacting alcohols with ethylene oxide, optionally under excess pressure, at higher temperatures in two-stage reaction in the presence of catalysts, acidic catalysts being used in the first stage and these being neutralized after condensation has taken place, then alkaline catalysts are used in the second stage and further ethylene oxide is condensed, advantageously obtained when ethylene glycol or a low molecular weight polyethylene glycol is used as the alcohol .

According to the process in the first stage, i.e. when using acidic catalysts, one obtains advantageous polyethylene glycols with molecular weights up to about 370, which is an average of eight

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._. ■ - "■■■ - ■ -. ³ - ⁴

(—CH ₂ —CH ₂ —O -) groups. For the specified in a solvent, such as lower

subsequent production of higher molecular weight polyalcohols and water, dissolved, to.

ethylene glycols in a second stage from the conversion The implementation is advantageous in the second stage

Settlement product obtained in the first stage, adhered at temperatures between 110 and 170 ⁰ C, in particular

is then used alkaline catalysts. The 5 "special, between 120 and 130 ⁰ C, carried out,

thus obtainable higher molecular weight "polyethylene glycols" The ethylene oxide is in the desired amount such as

have added molecular weights from 400 to 4000th described. The pressures are generally

Namely, already in the first stage, ie with my, similar to the reaction in the first acidic catalysts available polyethylene glycols stage I = ^{5 to 16 10} to instruct a bright, to many cases colorless loading It performs the procedure generally as through, creation. Aberration the products that you get the starting material in a heatable by further conversion with ethylene oxide in counter-reaction vessel with mixing device with the waiting of alkaline catalysts from them, catalyst added, the mixture on the reaction are considerably lighter in color than those that are temperature heated and the desired amount of ethylene by the known method in an only alkaline ¹ S oxide to the extent to which it is implemented, catalyzed conversion using The reaction vessel will then produce the same degree of purity after the neutral ethylene oxide and after addition of the leave alkaline catalyst. Another major advantage of being implemented with more ethylene oxide. A prior to the claimed process available poly- separation of low molecular weight components is not ethylene glycols is that they are easy, z. B. ao required because the molecular weights of the components with dilute hydrogen peroxide at Tempe- des mixture obtained in the first stage, temperatures below 100 ⁰ C, can be decolorized. The polyethylene glycols are, if desired, obtainable products lightened in a more uniform composition, for example by treating with active ingredients those obtained by the known charring or by exposure to 0.1 to 0.3 dangers, which is desirable in some cases. weight percent of 30% hydrogen peroxide on the

Ethylene glycol and polyethylene glycol in the form of a concentrated, z. B.

low molecular weight polyethylene glycols, for example 80%, aqueous solution at temperatures below

those with up to four (—CH ₂ —CH ₂ -O -) groups of 100 ° C.

pen, especially diethylene glycol. 30 The produced by the method according to the invention

Of the suitable acidic catalysts, adjustable polyethylene glycols can be found, for example

Phosphoric acid, oxalic acid, zinc chloride, silicon use in pharmaceutical and cosmetic

hydrofluoric acid, hydrofluoric acid, boron see industry.

fluoride or boron fluoride etherate and, in particular, the parts mentioned in the following examples

Called sulfuric acid. They are advantageously used in 35 parts by weight.

Amounts from 0.01 to 5 percent by weight, in particular “. . , ..

from 0.05 to 1 percent by weight. Particularly sensitive ^l ^ ¹

the use of sulfuric acid is absent, in a pressure vessel with a stirrer

which, with a view to the lightest possible color of the 450 parts of diethylene glycol with a solution of

Reaction product, expediently in the form of about 40 1.4 parts of 98% sulfuric acid in 18 parts of water

2 to 50%, in particular 3 to 20%, aqueous added and the mixture to 95 to 98 ° C

gene solution is added. heats. The air is displaced by nitrogen and

The reaction is carried out in the first stage at 1060 parts of liquid temperatures between about 70 and 120 ° C., pre-ethylene oxide is continuously run in over a period of 30 hours. The pressure is preferably between 90 and 100 ⁰ C, through. 45 carries 1.5 to 3.9 ata. 1350 parts are obtained

The ethylene oxide is gaseous or in an almost colorless polyethylene glycol with a liquid

Form and in the first stage advantageously in a sol-average molecular weight of 357.

chen amount that polyethylene glycols with 375 parts of the same are then 0.75 parts

average molar weights up to about 370 decalcined soda added and at 130 ⁰ C to the above

stand, applied. 50 described manner with 476 parts of ethylene oxide to

The applied when using liquid ethylene oxide. The end product obtained is 790 parts

occurring pressures, depending on the implementation of polyethylene glycol with a molecular weight of

temperature, about 1 to 16 ata. about 800. It is pale yellow in color and can be

For the subsequent manufacture yet easily purified by treatment with 30% hydrogen High molecular ethylene glycols, for example with 55 peroxide at 90 ⁰ C in a colorless state überMolgewichten of 400 to 4,000, neutralized to perform.

the acid catalyst, e.g. B. by adding Example 2
Sodium hydroxide, sodium carbonate or sodium

alcoholate, and adds an alkaline catalyst, 1800 parts of diethylene glycol are mixed with a solution

for example potassium bicarbonate or one of the 60% solution of 1.2 parts 98% sulfuric acid in 16 parts

substances designated as suitable for neutralization, too. added parts by weight of water and at 90 to 95 ° C with

Of the alkaline catalyst which can also be used, 3000 parts by weight of ethylene oxide in the example 1

other alkali metal alcoholates, such as sodium, are implemented as described,

methylate, potassium isopropylate and the alkali metal alcoholates 450 parts of the polyethylene glycol thus obtainable

the starting materials, called. The catalyst is then set to have a molecular weight of about 280

Sator expediently in amounts of 0.1 to 2%, in particular with 2 parts by weight of sodium methylate (in the form of a

especially from 0.5 to 1%, based on that in the approximately 30% methanolic solution). Man

polyethylene glycol obtained in the first stage, and the methanol is distilled under reduced pressure

10

from, the residue is heated to 120 to 130 ⁰ C and reacts it in the manner described in Example 1 with 430 parts by weight of ethylene oxide. The pressure is 1.3 to 2.0 ata. The end product obtained is 820 parts of an only slightly colored polyethylene glycol with a molecular weight of 550 which becomes colorless on treatment with highly diluted hydrogen peroxide at 90.degree.

Example 3

500 parts of ethylene glycol are mixed with a solution of 1.0 part of 98% sulfuric acid in 5.0 parts Water added and at 90 to 95 ° C with 1780 parts of ethylene oxide within about 50 hours in the implemented in the manner described in Example 1. 2030 parts of a colorless polyethylene glycol are obtained with an average molecular weight of about 280.

280 parts of this polyethylene glycol are then neutralized by adding sodium methylate, and 5 parts of sodium methylate (in the form of an approximately 30% strength methanolic solution) are then added. Distilling the methanol off under reduced pressure, the residue is heated to 120 to 13O ⁰ C and converts it with further 1230 parts of ethylene oxide. The pressure is 1.3 to 3.8 ata. One receives 1400 parts of a polyethylene glycol with a molecular weight of about 1500, which easily - z. Can for example in the form of its 80% aqueous solution by the action of 30% hydrogen peroxide discolor at about 9O ⁰ C.

Claims (4)

PATENT CLAIMS: 1. Process for the preparation of higher molecular weight, colorless to pale colored alcohols which _{contain the grouping —CH 2} —CH ₂ —O—, with molecular weights of 400 to 4000 by reacting alcohols with ethylene oxide, optionally under excess pressure, at higher temperatures in two stages Reaction in the presence of catalysts, acidic catalysts being used in the first stage and these being neutralized after condensation has taken place, then alkaline catalysts are used in the second stage and further ethylene oxide is condensed, characterized in that the alcohol used is ethylene glycol or a low molecular weight polyethylene glycol. 2. The method according to claim 1, characterized in that the acidic catalyst in Amounts from 0.05 to 1 percent by weight (based on the starting material) and the alkaline Catalyst in amounts of 0.5 to 1 percent by weight (based on the reaction in acidic medium obtained reaction product) applies. 3. The method according to claim 1 and 2, characterized in that the acid catalyst 3 to 20% aqueous sulfuric acid is used. 4. The method according to claim 1 to 3, characterized in that the reaction is carried out in the first stage between 90 and 100 ⁰ C and between 120 and 130 ° C in the second stage. Considered publications:
German Patent No. 890 642;
German interpretation U2915 IVd / 39c
acquainted on December 22nd, 1955); U.S. Patent Nos. 2,674,619, 1,970,578. © 309 599/357 5.63