DE1025855B - Process for the production of moisture-retaining sorbitol monoethers of 1,2-alkylene glycols - Google Patents

Description

The invention relates to the production of sorbitol monoethers of 1,2-alkylene glycols, the new Represent products with valuable moisturizing properties.

Sorbitol has many of those required for an ideal moisturizing and moisture conditioning agent Properties: It is stable, not at all volatile and stabilizes the moisture content of treated substances in a satisfactory manner. However, it has a disadvantage of using it as a humectant seems unsuitable for a number of types of application: namely, it is at room temperature a solid crystalline substance and can, under conditions of low humidity, from mixtures, in which it is contained as a wetting agent, crystallize out.

Numerous attempts have been made with varying degrees of success to find sorbitol-containing or sorbitol-related To produce mixtures that do not have this undesirable tendency to crystallize. The USA patent 2172 357 describes e.g. B. a mixture produced by electrolytic reduction of types of sugar under certain Conditions is produced and the sorbitol along with considerable amounts from the reduction Contains resulting by-products that are intended to prevent the crystallization of the sorbitol. To these mentioned By-products are said to be deoxyhexites and pentites, anhydrous hexites and organic acids or their salts belong.

Processes have recently been developed by which very pure sorbitol can be produced economically on a large scale Way can produce by catalytic hydrogenation under pressure. One aim of the present invention is it now, very pure sorbitol, obtained by such a catalytic hydrogenation of glucose or otherwise is available to convert into products that enhance the hygroscopicity and moisturizing properties of sorbitol but do not crystallize at ordinary temperatures.

According to the invention, sorbitol monoethers of 1,2-alkylene glycols, in which the alkylene group contains no more than 3 carbon atoms, are prepared in a known manner by condensation of sorbitol with a 1,2-alkylene oxide containing no more than 3 carbon atoms, optionally up to 5 ° / ₀ water may be present. Small amounts of water of up to about 5% can be present in the sorbitol without noticeably disrupting the course of the reaction. The product thus obtained may accordingly contain minor amounts of unreacted sorbitol, alkylene glycols and higher oxyalkylated sorbitol derivatives, but the main component is the monosorbitol of an alkylene oxide and the reaction mixture can be used for the present purpose as such without purification.

Method of manufacture

Moisture retentive

Sorbitol monoether of 1,2-alkylene glycols

Applicant:

Atlas Powder Company,
Wilmington, Del. (V. St. A.)

Representative: Dr. W. Beil, lawyer,
Frankfurt / M.-Höchst, Antoniterstr. 36

Claimed priority:
V. St. v. America April 17, 1953

John David Brandner, Arden, Del. (V. St. A.),
has been named as the inventor

For the preparation of ethers according to the invention one to 9O ⁰ C pre-warmed to 85 autoclave with dry or only slightly water-containing sorbitol is charged together with a catalyst for the reaction. The air is then removed from the autoclave, the charge is heated to the reaction temperature with stirring and alkylene oxide is introduced in such portions that the pressure in the autoclave does not rise above 4.22 atm. After a molar amount of the oxide has been added, heating and stirring are continued until the reaction has ended, which can be recognized by the pressure drop to a constant value. Depending on the type of catalyst selected, the oxide and the reaction temperature, this can take 6 to 36 hours. The reaction takes place at temperatures as low as 100 ^° C .; But to achieve practically useful reaction rates it is necessary to work at temperatures above 125 ° C and preferably at 140 to 15O ⁰ C. On the other hand, it is recommended not to let the temperatures exceed 175 ° C.

The condensation is promoted by both basic and acidic catalysts. To the appropriate Reaction catalysts include sodium methylate, sodium hydroxide, primary, secondary and tertiary Disodium, sodium phosphate, phosphoric acid, boron trifluoride, sodium acetate, mixtures of sodium acetate and Acetic acid, acetic acid itself, and the like. Of these, primary sodium phosphate is the best catalyst. The cata-

709 909/400

Analyzers are present at concentrations ranging from 0.25 to 2 percent of the total reactant charge weight effective. Preferably about 0.5% is used.

The other special conditions for the preparation of the invention are described in the following examples Ether can be seen.

example 1

An upright, provided with stirrer autoclave of 7,561 contents were heated to about 100 ⁰ C and 3.22 kg of a sorbitol solution, which has been up to a water content of 2.13 ° / ₀ and concentrated and preheated to 80 to 90 ⁰ C. was, and charged with 20 g of sodium methylate as a catalyst. The oxygen was removed from the autoclave by purging with nitrogen below 0.7031 atm and venting the gas. The autoclave was then closed, began stirring, and the charge was heated to 14O ⁰ C. Ethylene oxide was pumped in until the pressure had risen to 4.2 at. The introduction of ethylene oxide was then interrupted until the reaction had consumed so much of it that the pressure had dropped to 2.8 at. Further portions of such a height were then repeatedly added and so often that the pressure was between 2.8 and 4.2 atm, up to a total addition of 820 g. This represents a 50 ° / ₀ by weight excess is with respect to a molar amount of the sorbitol syrup presented. The reaction mixture was ^{kept at 140 °} C. until the pressure had fallen to a practically constant value. The addition and reaction with the ethylene oxide took a total of 15 hours. After the reaction mixture had cooled to 100 ° C., the autoclave was emptied and the mixture was filtered. The filtrate was a light-colored syrup of very high viscosity with 1.45% water content and the hydroxyl number 1475, converted to anhydrous state. The mixture was miscible with water in any proportion and showed no tendency to crystallize at any concentration.

Further preparations were made by following the procedure of Example 1 with those given in the following table Modifications made.

Tabel

3 1.72 example 1.9 5 1.4 6th 1.9 2 3220 4th 3220 3030 3030 2.14 H ₃ PO ₄ * NaH ₂ PO ₄ NaH ₂ PO ₄ BF ₃ ** 3220 5.85 ml 20 g 20 g 4g Na ₃ PO ₄ Ethylene Ethylene Propylene Propylene 20 g 820 820 1010 1010 Ethylene 140 140 140 130 820 8th 11 14th 9 140 4.4 0.82 0.4 1.22 12.5 1340 1410 1385 1378 1.3 1487

Water in sorbitol, ° / ₀

Starting sorbitol, g

catalyst

Amount of catalyst

Alkylene oxide

Weight of alkylene oxide, g

Reaction temperature ^{, 0 C}

Response time, hours,

Water content of the reaction product, ° / ₀

Hydroxyl number (calculated on the anhydrous state) -

* 85% H ₃ PO ₄ solution.
** BF ₃ ether complex (48% active ingredients).

All of the products obtained were viscous, hygroscopic, syrupy liquids. It is worth mentioning -that the strongly acidic catalyst according to Example 3 accelerated the anhydration of the sorbitol residue, which in a slightly lower hydroxyl number and higher water content after removal from the autoclave is expressed. For many purposes this anhydration is not detrimental, although it is generally is better avoided, which is why strongly mineral acid catalysts are not so cheap.

Example 7

This example illustrates the condensation of about 2 ° / ₀ water containing sorbitol syrup with ethylene oxide in a slightly larger scale in a flask equipped with circulating device autoclave.

142.5 kg of sorbitol syrup with 2% water content was heated to 85 ° C. and, together with 885 g of NaH ₂ PO ₄ hydrate, placed in a pressure reaction vessel in which the charge could be circulated through heat exchange coils outside the actual reaction vessel. The air was displaced from the system by letting in nitrogen below 0.7 at and then releasing this gas. The recirculation began, the charge was heated to 145 ° C., and ethylene oxide was pumped into the reaction chamber in small quantities, the pressure always being kept below 3.86 atm. In the course of 11 hours, a total of 35.8 kg of ethylene oxide were introduced, whereupon the circulation was continued at 145 ° C. until the pressure had dropped back to 0.21 atm, which took another hour. The pressure was now released and the autoclave was emptied. The product was up to a content of 5% mixed with water and maintained by addition of 1 ° / ₀ activated carbon by spraying the slurry into a chamber in which to draw a vacuum of 380 mm, and decolorized 15 minutes long pumping at HO ⁰ C and made odorless. The vacuum was then released and the pumping continued for a further 45 minutes, the charge was ^{cooled to 100 °} C. and filtered. The resulting product was a light colored syrup with 5% water content, a viscosity of about 7500OcP at 25 ⁰ C and a hydroxyl number of 1498 (calculated at anhydrous state). It was miscible with water in all proportions and showed no tendency to crystallize on standing for a long time or on drying out.

Example 8

In the autoclave described in Example 7, 44 kg of propylene oxide and 133.5 kg of sorbitol with a water content of 2.13% were condensed by the method described above. 885 g of NaH ₂ PO ₄ -H ₂ O were used as a catalyst; the reaction time was 13 hours. After the addition of water, up to 5%, the end product had a viscosity of 137,000 cP at 25 ° C. and a hydroxyl number (calculated on the anhydrous state) of 1415.

The products of the invention are useful for many industrial applications. As a humectant and plasticizer for flexible types of glue and glue mixtures, they have all the advantages of sorbitol without having the aforementioned tendency to crystallize out on the surface of the mixtures when these are stored in a dry atmosphere. Flexible types of glue, for which the novel humectants according to the invention can be used as additives , are advantageously used in bookbinding for sealing tapes and as a binding agent component in artificial cork pellet mixtures for sealing rings, bottle closures and the like. Other mixtures based on glue or gelatin which can advantageously be plasticized with the products according to the invention are soft gelatin capsules, gelatin foils and films, hectographing compounds and printing rollers. In such mixtures, the plasticizer can contain the novel products according to the invention together with the usual plasticizers made from polyhydric alcohols, namely glycerol, lower glycols and the like.

The products of the invention also have a wide variety of uses in the textile and related industries Find. You can use them to maintain textile finishes the moisture content of the fiber finishing system and for the production of products incorporate with a good grip and case. For plasticizers and conditioning agents in textile sizes, especially in gelatin-containing chain sizes, starch sizes and synthetic sizes as well as those based on of polyvinyl alcohol and other water-dispersible synthetic resins are those of the invention Sorbitol monoether is particularly suitable.

The products according to the invention are useful as conditioning agents for textile printing pastes and vat color pastes also very useful. Apart from its tendency to crystallize under dehydration conditions, sorbitol is extremely well suited for this type of application in every respect. With the invention Ether-made printing pastes, on the other hand, remain permanently soft and completely printable, even if their Moisture has evaporated to very low levels, for example when applied as a thin film coming pastes during a temporary shutdown of the effect of the heated press Rollers are exposed. There is therefore no need to scrape off dried flakes from the engraved roller or peel off so that there is no risk of damaging the printing surface.

The compounds according to the invention can also be used alone or together with other polyoxy compounds as a plasticizer for films made from regenerated cellulose, soft papers and for parchment-coated paper to serve. Their permanently fluid nature and their non-volatility make them permanent as plasticizers effective.

Other types of application of these substances are obvious to the person skilled in the art. In cosmetic and Pharmaceutical products retain their softness and absorbency, e.g. B. at Pastes and creams. They are also well suited as humectants for tobacco and tobacco products.

If the products according to the invention still contain reactive hydroxyl groups, they can finally as intermediates for the production of other chemical compounds such as esters, acetals, ketals and ethers, to serve.

Claims (5)

Patent claims: 1. Process for the production of moisture-retaining sorbitol monoethers of 1,2-alkylene glycols, wherein the alkylene group contains no more than 3 carbon atoms, characterized in that the Sorbitol with a 1,2-alkylene oxide, which is no more than Contains 3 carbon atoms, optionally condensed in a known manner in the presence of up to 5% water. 2. The method according to claim 1, characterized in that sorbitol and 1,2-alkylene oxide approximately equimolar proportions are used. 3. The method according to claim 1 or 2, characterized in that a catalyst for the reaction is used. 4. The method according to claim 1, 2 or 3, characterized in that the reaction under increased Pressure is carried out, which preferably does not exceed 4.2 atm. 5. The method according to claim 1 to 4, characterized in that the reaction at 100 to 175 ⁰ C, preferably at 140 to 150 ⁰ C, is carried out. Considered publications:
German Patent Nos. 598 596, 705 450,605973; British Patent No. 602 591. , © 709 909/405 p.