DE2952477A1 - Higher alkyl:amine poly:phosphate or meta:phosphate prodn. - by treating amine soln. in organic solvent with aq. poly- or meta-phosphate, useful as heavy metal complexing agent - Google Patents

Abstract

In a new process for the prodn. of water-insoluble alkylamine polyphosphates and/or metaphosphates, higher (8-30C)alkylamines of the formula R1-N(R2)(R3) (I) (where R1 and R2 are H or alkyl and R3 is alkyl) dissolved in an organic solvent which is immiscible with water and mineral acids are reacted with polyphosphoric acid and/or metaphosphoric acid so that the resulting alkylamine polyphosphate and/or metaphosphate is dissolved in the organic solvent and excess polyphosphoric acid and/or metaphosphoric acid migrates into the aq. phase. The phases are subsequently sepd. and the alkylamine polyphosphate and/or metaphosphate is isolated from solvent. The higher alkylamine poly-and/or metaphosphate prods. are water-insoluble cpds. which are complexing agents for heavy metals.

Description

Process for the production of water-insoluble

Alkylamine poly and / or metaphosphates The present invention relates to a process for the preparation of water-insoluble amine polyphosphates and / or amine metaphosphates from amines and poly and / or metaphosphoric acids.

Amines are able to form salt-like compounds with acid. Depending on the chain length and number of alkyl radicals, the salts formed show the Amines behave differently towards water and other solvents. For example, the amines with shorter-chain alkyl radicals in water are whole or limited solubility. Through the formation of salts with acid residues, especially acid residues of the mineral acids, the solubility in water is increased.

There are water-soluble amine polyphosphates known that by reacting of amines, e.g. Ethanolamines, made with polyphosphoric acids in aqueous solution will.

DE-PS 12 45 979 also describes the production of water-soluble Amine polyphosphates from acid alkali salts of polyphosphoric acids and amines and Addition of organic solvents known.

U.S. Patent 2,592,273 describes quaternary ammonium salts of high molecular weight Polyphosphoric acids and their production.

ED has now found a process for the preparation of water-insoluble alkylamine poly and / or metaphosphates from alkylamine and polyphosphoric acids and / or metaphosphoric acids, which is characterized by the fact that alkylamines which have 8 to 30 carbon atoms in the alkyl radical and the formula: correspond, where R1 and R2 are hydrogen or alkyl groups and R3 are alkyl groups, and which are dissolved in an organic solvent, these solutions not being miscible with water and mineral acids, with polyphosphoric and / or metaphosphoric acids, so that the amine polyphosphate or metaphosphate formed is dissolved in the organic solvent, and the excess polyphosphoric acid or metaphosphoric acid migrates into the aqueous phase, the phases are then separated and the amine polyphosphate and / or metaphosphate is isolated from the solvent.

It is possible to use those alkylamines which have 8 to 3 C atoms in the alkyl radical and the formula correspond, where R1 and R2 are hydrogen or alkyl radicals and R3 are alkyl radicals, and which result in solutions with organic solvents which are immiscible with water or mineral acid.

Primary, secondary or tertiary amines and mixtures thereof can be used can be used.

The amines or their mixtures are in organic solvents solved. The concentration of the amine in the solvent is not important, rather, it is based on the possibility of such solutions in practice to be able to handle.

The solvents must not be miscible with water and mineral acids Do not absorb his or her water and mineral acid. You need to have good solubility for the alkylamines and the alkylamine poly u / or metaphosphates, may but do not react with these themselves.

The following groups have proven to be particularly useful solvents proven: a) aliphatic and aromatic hydrocarbons in the form of defined Compounds, mixtures or distillation fractions b) chlorinated hydrocarbons c) ethers, ketones, esters, as long as they meet the above conditions.

As useful polyphasphate and / or metaphosphate components for production of the amine-poly-phosphates and / or -metaphosphates, the following substances have been found: Di-phosphoric acid tri-phosphoric acid tetra-phosphoric acid medium to long-chain polyphosphoric acid cross-linked polyphosphoric acid made from Kurrol's salt tri-metaphosphoric acid Tetra-metaphosphoric acid and mixtures thereof, such as those used when concentrating from monophosphoric acid.

Altylamine polyphosphate and / or metaphosphate can be different Kind be formed. For example, it is possible to use an alkali and ammonium salt of polyphosphoric acid u / or metaphosphoric acid to dissolve in the orthophosphoric acid, with the corresponding Free polyphosphoric acid and / or metaphosphoric acid forms, which then of the added Alkylamine is added.

It is also possible to use free polyu / or metaphosphoric acid instead of a salt to use as they are z.O. arise during evaporation of orthophosphoric acid.

It is also possible and particularly advantageous to use polyphosphoric acid u / or metaphosphoric acid by treating an alkali and / or ammonium polyphosphate Uloder metaphosphate solution to be prepared separately with a cation exchange resin and introducing the eluate directly into the organic solution of alkylamine and solvent. Two phases are formed, with polyphosphoric acid and / or metaphosphoric acid migrates into the organic phase and forms the compound with the alkylamine. the heavy phase consists of an aqueous solution of excess polyphoaphoric acid ulor metaphosphoric acid, which is separated. The isolated organic phase exists from the alkylamine polyphosphate and / or metaphosphate salt formed. The organic one Solvent is removed by gentle distillation. The distillation residue represents the alkylamine polyphosphate or metaphosphate compound.

The alkylamine polyphosphates obtained in the process according to the invention u / or metaphosphates are high molecular weight substances whose molecular weight is between 300 and about 4,300,000, preferably between 1,000 and 70,000. In the Use of a long-chain polyphosphoric acid with a degree of polymerization of n = 30 and an amine of 36 carbon atoms result in compounds with a molecular weight of approx. 13,000, the molar N: P ratio being approx. 1: 1.

Figure 1 shows the quantitative relationship between the reactants Alkylamine and polyphosphoric acid excel in the formation of alkylamine polyphosphate. The absorption of long-chain polyphosphate ions in moles is plotted on the abacissa.

The amounts of amine dissolved in the solvent are on the ordinate given in moles. It turns out that there is a linear relationship between the mitcinander reactive amounts of polyphosphate and amine is given.

Are other starting materials for the formation of the Alkylaminpolyphosphatu / or metaphosphate compound selected in the process of the invention, then the molar N: P ratio is within the limits of 1: 2 to 2: 1.

Furthermore, the salt-like character of the alkylamine polyu / or results metaphosphates from the position of the signals in the 13C and 31p -NMR spectra. The signal of the NCH2 group shows a characteristic in the C nuclear magnetic resonance spectrum of the salt Shift to a lower field compared to the free alkylamine. Also shows the 13C-NMR spectrum that the alkylamine has been converted quantitatively into the salt is (Figure 2). The 31P-NMR spectrum shows that all P-members of the Polyphosphoric acid are equally saturated with alkylamine molecules. The location of the 1P nuclear magnetic resonance signal is typical of a phosphate salt.

The facts presented here can be seen on the basis of the 31P-NMR spectra trace in Figure 3 and 4.

The alkylamine is used as a free base in an organic solvent solved. The solvent mix is mixed with an aqueous solution of polyphosphoric acid brought in contact.

The reaction between the alkylamine and the polyphosphoric acid takes place takes place at the phase boundary. The alkylamine salt formed is from the organic Solvent dissolved and remains in the organic phase. The reaction between the alkylamine and the poly- and / or metaphosphoric acid run stoichiometrically.

As a rule, a small excess of acid is used, to add any alkylamine dissolved in the organic solvent to the salt overdo it. The excess acid remains in the aqueous phase. At this The procedure eliminates the need to separate the free, unreacted alkylamine from the alkylamine salt. The reaction between the reactants is very quick and follows the resection progress with a neutralization reaction.

The reaction can be carried out in batches in closed tubular vessels will. For better utilization of the free poly and / or metaphosphoric acid available the reaction can also be carried out in a countercurrent extraction apparatus, whereby from one side the organic solvent with the free amine and from on the other hand, the aqueous acid solution into the countercurrent extraction apparatus be introduced.

The course of the reaction is exothermic. It may therefore be necessary to condense the evaporating organic solvent through a recooling system. This is always the case when the reactants are in relatively high concentration are present.

Usually, the process of the invention is carried out with an alkylamine solvent mixture with an alkylamine content of 1-10% and an aqueous poly and / or metaphosphoric acid solution operated from 0.5 - 5.0 X. Within these concentration limits, the Mastering the reaction process without special precautions, for example a recooling system.

However, the implementation can also come from other areas of concentration be made. For example, the polyphosphoric acid solution obtained by Condensing orthophosphoric acid can be used. Preferably an acid with approx. 30% P205 is used for this.

In the reaction of the condensed phosphoric acid with alkylamine remains the orthophosphoric acid contained in the acid mixture in the aqueous phase, during the poly- and metaphosphoric acid forms the alkylamine salt and enters the organic phase wanders.

After the reaction of the alkylamine with the polyul or metaphosphoric acid the phases are separated. The aqueous phase, which may have an excess contains poly- and / or metaphosphoric acid, is either sharpened again with the acid and used again or discarded. The organic phase contains what is formed Alkylamine poly and / or metaphosphate.

It is first washed with water to remove any debris that has been carried away to eliminate the aqueous acid phase. This can be done either in batches or in batches be carried out in countercurrent.

Then the organic phase, consisting of solvent, alkylamine poly- u / or metaphosphate, subjected to a gentle distillation. The distillation is carried out as vacuum or vacuum thin-layer distillation. After After the organic solvent has been separated off, the reaction product remains as a distillation residue.

The isolated alkylamine polyphosphates and / or metaphosphates are liquid highly viscous to waxy solid bodies. They cannot be distilled without decomposing themselves will. As liquids, they have a colorless to pale yellow appearance. as solid or waxy bodies they have a white appearance. You are not in Water soluble. They are very soluble in both non-polar and polar ones Solvents. They have complex-forming properties for heavy metals.

Example 1 480 parts by weight of naphthabenzine were added to a closed stirred vessel Bp 100-1200C submitted. While stirring, 20 parts by weight of a solvent own tridodecylamine base dissolved.

In another open stirred vessel, an aqueous 5.0% aqueous solution was added Solution made from long-chain sodium polyphosphate.

This solution was via a strongly acidic H + -charged cation exchanger converted into the free polyphosphoric acid. The polyphosphoric acid solution obtained in this way had a P 205 content of 3.46%. The aqueous polyphosphoric acid was in one Receiving tank caught.

80 parts by weight of the aqueous polyphosphoric acid solution were in the stirred vessel and by switching on the agitator with the 500 parts by weight the alkylamine-n-phthabenzine solution thoroughly mixed for 15 minutes. During the During the mixing process, the temperature in the solution rose by approx. 1.00C from 250C to 260C at.

After the agitator was shut down, the floor drain of the Stirring vessel drained the aqueous phase. The expiring solution had one more Residual P205 content of 0.096%. It was used to make a new sodium phosphate solution used.

The organic phase remaining in the stirred vessel with the dissolved tridodecylamine polyphosphate salt was carried away by washing twice in a row Polyphosphoric acid solution freed during the reaction.

200 parts by weight of desalinated water were used for each washing process. The washing water running off had the following P 205 contents: Wash water I: 0.022 X P205 washing water II: <0.002% P2O5 After the clean separation of the With the washing water, the tridodecylamine polyphosphate naphtabenzine solution was poured into the still transferred to a vacuum distillation and at a bottom temperature of 32 ° C and a Pressure of 14 torr driven off the solvent. The still residue existed from a liquid, oily, slightly yellowish colored product. After cooling down at room temperature the consistency of the product changed to a highly viscous one viscous substance. The analysis for P 205 and N2 gave the following values: P205: 11.30 % N2: 2.14 X.

The yield, based on the alkylamine used, was 99.5%.

Example 2 In the preparation of di-n-octylomin tripolyphosphate were the same equipment and workflows as described in Example 1 were used. However, in contrast to the information in Example 1, those used for the reaction had Solutions following data: The alkylamine solution was prepared by adding 20 parts by weight a 94% di-n-octylamine base were dissolved in 300 parts by weight of dibutyl ether.

The aqueous tripolyphosphoric acid solution was made from a 10% sodium tripolyphosphate solution manufactured. It had a P205 content of 5.79%.

For the reaction with the di-n-octylamine solution, 65 wt.

Part of the aqueous acid solution prepared. The after implementation The aqueous phase running off still had a residual P205 content of 0.44% a temperature increase of 4 ° C. occurred during the reaction.

The organic phase was washed three times with 100 parts by weight each time carried out in desalinated water. The washing water running off had the following P205 contents: Wash water I = 0.144 X P205 wash water II = 0.013% P2O5 wash water III = 0.002 % P2O5 The residue remaining after the solvent had been separated off existed from a waxy solid white mass. There were 120 parts by weight in the implementation of the product won.

The analysis for P205 and N2 gave the following values: P205 = 14.57% N2 = 4.51 X.

Examples 3-11 In addition to the workflows described in more detail in Examples 1 and 2 for the preparation of alkylamine polyphosphates, further alkylamine polyphosphate compounds were prepared from primary, secondary and tertiary alkylamine bases. Their properties are summarized in the table below: Type of compound Description Analysis data Molar ratio Mol-wt. consistency % P2O5% N2 N / P 1) [(RH2N) HPO3] n isonanylamine- 29.50 6.00 1.03: 1.00 about 6700 solids polyphosphate n = 26-34 2) (RH2N) 5H5P3C10 isonanylamine- 21.38 6.85 1.62: 1.00 973 viscous tripolyphosphate 3) [(RH2N) HPO3] 4 isonanylamine- 31.15 6.08 0.99: 1.00 892 pasty tetrapoly- phosphate 4) (R2HN) 5H5P3O10 ** Dioctylamine- 14.57 4.51 1.57: 1.00 1463 solids tripolyphosphate 5) [(R2HN) HPO3] n dioctylamine- 21.90 4.42 1.02: 1.00 about 9600 viscous n = 26-34 polyphosphate 6) [(R2NH) HPO3] 3 dioctylamine 22.29 4.48 1.02: 1.00 963 pasty trimethaphosphate 7) (R3N) 4H4P2O7 tridodecylamine- 6.08 2.39 2.00: 1.00 2266 syrupy pyrophosphate 8) (R3N) 5H5P3O10 Tridodecylamine- 7.20 2.28 1.60: 1.00 2868 pasty tripolyphosphate 9) [(R3N) HPO3] n Tridodecylain-11.3 2.14 0.96: 1.00 about 18000 viscous n = 26-34 polyphosphate 10) [(R3N) HPO3] n crosslinked chain. 12.05 2.18 0.92: 1.00 about 480000 waxy n = 800-2000 tridodecylamine- 1,200,000 polyphosphate 11) [(R3N) HPO3] 3 tridodecylamine- 11.80 2.33 1.00: 1.00 1806 pasty trimetaphosphate * as described in example 1 ** as described in example 2

Claims (4)

A process for the production of non-water-insoluble alkylamine polyphosphates and / or alkylamine metaphosphates from alkylamine and polyphosphoric acids and / or metaphosphoric acids, characterized in that amines which have 8 to 3C carbon atoms in the alkyl radical and the formula correspond, where R1 and R2 are hydrogen or alkyl radicals and R3 are alkyl radicals, and which are dissolved in an organic solvent, whereby these solutions are not miscible with water and mineral acids, with polyphosphoric and / or metaphosphoric acids, so that the formed alkylamine polyphosphate uloder metaphosphate is dissolved in the organic solvent, and the excess polyphosphoric acid and / or metaphosphoric acid taandert in the aqueous phase, the phases are then separated and the alkylamine polyphosphate and / or metaphosphate isolated from the solvent. 2) Method according to claim 1), characterized in that the Pnlyphosphoric acid and / or metaphosphoric acid by atinn £ riaexausch won by an alkali salt of poly- and / or metaphosphoric acid with an acidic catalyst exchange resin implements. 3) Method according to claim 1), characterized in that the Poly- and / or metaphosphoric acids obtained by condensing orthophosphoric acid. 4) Method according to claim 1), characterized in that the Poly and / or metaphosphoric acids by dissolving poly and / or metaphosphates in orthophosphoric acid wins and the thus formed poly and / or metaphosphoric acids with the amine, dissolved in organic solvent, extracted.