DE102006021523A1 - Preparation of phosphorus-containing alkoxylated product, useful as fire retardants in polyurethane, comprises reacting phosphorus trihalides and/or phosphorus oxyhalides with alkylene oxide, using aluminum as a catalyst - Google Patents

Abstract

Preparation of phosphorus-containing alkoxylated product comprises reacting phosphorus trihalide and/or phosphorus oxyhalides with alkylene oxide, using aluminum as a catalyst.

Description

The The invention relates to a process for the production of phosphorus-containing Alkoxylation products by means of aluminum as a catalyst, which as Flame retardants can be used in polyurethanes.

The Production of phosphorus-containing alkoxylation products, in particular of organic phosphonates and halogen-substituted alkyl phosphates is known in the art. It is mainly phosphoric acid, phosphorous Acid or Phosphorus trihalide, preferably phosphorus trichloride or phosphorus oxyhalide, in particular phosphoroxychloride, used and with epoxides such as Implemented ethylene oxide, propylene oxide and / or epichlorohydrin. to increase The reaction rate is often used catalysts. For homogeneous working catalysts are known in the art many variants.

in the Generally need but the obtained alkoxylated products are extensively cleaned, since one Isomer mixtures. The aftertreatment is usually by an aqueous workup of the crude reaction products achieved, wherein the catalyst irreversibly destroyed and separated becomes.

This is eg in DD 125 035 wherein inactivation or destruction of the titanium halide catalyst used there is achieved by adding a stoichiometric amount of water or washing the phosphorus-containing alkoxylation with water or alkalis.

such After-treatment for destruction or inactivation of the catalyst, however, have disadvantages. she require in addition Reactors, it comes to a deterioration of the space-time yield and it occurs Product losses. The resulting wash water must be disposed of consuming. Not Finally, the catalyst used for further use is lost.

A continuous production method of 2-haloalkylated phosphates using heterogeneous catalysts is reported in CN 1 034 206 described. BeO is used here. The process allows the production of low-acid products (acid number <0.2 mg KOH / g substance) such as (MeCHClCH ₂ O) ₃ PO, (ClCH ₂ CHClCH ₂ O) ₃ PO and (ClCH ₂ CH ₂ O) ₃ PO.

In US 3 557 260 the use of sulphates of different elements is proposed. The required reaction time is about 80 h and takes much longer compared to the prior art for economic processes.

The It is an object of the present invention to provide a process for the preparation of phosphorus-containing alkoxylation products using to develop a catalyst, ideally an optimized isomer supplies, but itself is hardly detectable in the product mixture.

• a) zunächst die Phosphortri- und/oder Phosphoroxihalogenide mit Aluminium kontinuierlich umsetzt,
• b) das Umsetzungsprodukt aus a) in einen Reaktor überführt und dort mit Alkylenoxiden zur Reaktion bringt.

The solution of the problem and thus the subject of the present invention is a process for the preparation of low-acid, phosphorus-containing alkoxylation by reaction of phosphorus tri- and / or Phosphoroxihalogeniden with alkylene oxides, characterized in that

• a) initially the phosphorus tri- and / or phosphorus oxyhalides continuously reacted with aluminum,
• b) transferring the reaction product from a) into a reactor and reacting there with alkylene oxides.

Possibly includes to step b) a step c), the washing of the reaction product from b) by means of water or alkali washing.

Surprisingly show the prepared by means of aluminum as a catalyst phosphorus-containing Alkylation products in comparison to the prior art pronounced isomer ratio.

worin das Verhältnis der Isomere (I)/(II) in der Mischung > 2 ist.Thus, it is surprising that in the case of the inventive synthesis of tri (chloropropyl) phosphate, a mixture of isomers of isomers (I) to (IV) is obtained

wherein the ratio of isomers (I) / (II) in the mixture is> 2.

In a preferred embodiment, the process according to the invention thus relates to the synthesis of tri (chloropropyl) phosphate (TCPP) or the mixture of its configuration isomers, namely (MeCHClCH ₂ O ₃ ) PO, (ClCH ₂ CH ₂ CH ₂ ) ₃ PO, (ClCH ₂ CH ₂ CH ₂ O) (MeCHClCH ₂ O) ₂ PO, (ClCH ₂ CH ₂ CH ₂ O) ₂ (MeCHClCH ₂ O) PO).

Further Advantages of the method according to the invention based on aluminum as catalyst lie in the light, anhydrous separability of the catalyst from the educts and the reaction products. The easy separability thus allows it on an elaborate product washing largely to renounce and the production process against the State of the art to make more economical. Unreacted phosphorus tri- and / or phosphorus oxychloride can be recycled to the production process and used again.

When Phosphorus-containing starting materials are preferably in the process according to the invention Phosphorus tri- and / or Phosphoroxihalogenide, in particular phosphorus trichloride and / or Phosphoroxichlorid, used and individually or mixed with each other after passing by reacted on aluminum with the alkylene oxides. Examples for alkylene oxides are ethylene oxide, propylene oxide, styrene oxide, cyclohexene oxide, cyclopentene oxide, Glycidyl ether, epichlorohydrin, epoxidized polybutadiene, epoxidized unsaturated oils. The can Alkylene oxides also mixed with each other with the phosphorus tri- and / or Phosphoroxihalogeniden be used. In this way can phosphorus-containing alkoxylation products such as e.g. Tri (chloropropyl) phosphate (TOPP), tri (chloroethyl) phosphate (TCEP) tri (chloropropyl) phosphite or tri (chloroethyl) phosphite.

In a preferred embodiment is in step b) as the alkylene oxide propylene oxide and / or ethylene oxide used.

The Aluminum in step a) is preferably used in chips, in granulated form, used in spherical or aluminum grids. In any case one must be possible size surface available on aluminum stand.

Conceivable are also filled cartridges with, for example, aluminum granules which are suspended in a dissolving container, allowing them from the phosphorus tri- and / or phosphorus oxyhalides then the aluminum-containing mixture then the Reactor supplied becomes.

The execution of step b) and optionally to be performed step c) is the expert known, for example from methods of organic chemistry, Houben-Weyl, Vol. 12/2 p. 336 ff.

The inventive method for the preparation of phosphorus-containing alkoxylation by means of Aluminum as catalyst can be both continuous and discontinuous carried out become. Due to the step a), the method is preferred carried out continuously. It is characterized in that the aluminum before the reaction of phosphorus tri- and / or phosphorus oxyhalide with alkylene oxides in a dissolving container with the phosphorus tri- and / or Phosphoroxihalogeniden is brought into contact and the resulting reaction product together with not yet reacted phosphorus tri- and / or Phosphoroxihalogenid the reactor for the Reaction with an alkylene oxide is supplied.

The Temperature during the dissolution process of the aluminum in step a) should be in the range of 0 to 200 ° C, preferably 10 to 150 ° C, more preferably 15 to 100 ° C lie.

The Flow rate of phosphorus tri- and / or phosphorus oxyhalide on Aluminum catalyst depends on the implementation of stage b), but should be a continuous driving style too guarantee at 300 l / h. lie. After completion of stage a) the aluminum content is the reaction solution in the range of 10 to 1000 ppm, preferably in the range of 10 to 500 ppm.

As already described above, the implementation of stage b) the expert known. This is carried out at temperatures of 0 to 100 ° C. Preferably the reaction temperatures are between 50 to 80 ° C. The reaction takes place without pressure or under slight overpressure of up to 1 MPa. The reaction mixture from stage a) is initially charged in the reaction vessel and metered in the alkylene oxide continuously. The reaction medium can by adding phosphorus-containing alkoxylation with one of the reactants or separately diluted. After the end of the Alkylenoxiddosierung is at temperatures of 60 to 130 ° C a post-reaction phase connected and final by vacuum distillation or nitrogen stripping at temperatures from 90 to 150 ° C and pressing of up to <0.05 MPa volatile Removed impurities. Preferably, the removal of volatile Ingredients at approx. 130 ° C and about 40 mbar.

Examples

Synthesis of tris (chloropropyl) phosphate (TCPP)

In a three-necked round bottomed flask with reflux condenser, 0.2 g aluminum semolina and phosphorus oxychloride was initially charged and then boiled for 10 min. It was then cooled to 50 ° C and by means of a BF 411/30 (pumping rate: 0.5 ml / min), a mixture of POCl ₃ (11.7 g, 7 ml) and propylene oxide (20.9 g, 25.1 ml) was added dropwise. The temperature was kept by means of cooling bath between 50 and 60 ° C. After a stirring time of 180 min at 60 ° C, an analysis of the TCPP composition by GC, ³¹ P-NMR was performed. In addition, the aluminum content was determined by ion chromatography.

Content of TCPP ( ³¹ P { ¹ H} NMR):

• 99.8 mol% with respect to P

Composition (GC area% off the integration of the gas chromatogram):

• 68.5 (isomer I)
• 21.9 (isomer III)
• 2.8 (isomer IV)
• 0.12 (isomer II)
• 1.53 residual propylene oxide from GC:
• 1.9 TCPP Ether

Al content:

• 110 ppm

Studies on the Al content in phosphorus oxychloride from the reaction aluminum with POCl ₃ At different temperatures:

AAS

= Atomadsorptiosspektroskopie

A glass jacketed tube reactor (30 ml) was charged with aluminum granules (10.4 g, 1 mm diameter) and glass beads (23.5 g, 2-3 mm). The volume ratio Al / glass beads was about 1: 2. At Finally, phosphorus oxychloride was fed at a flow rate of 10 ml of POCl ₃ / h and the aluminum content was determined at various temperatures. From 85 ° C, the formation of a yellow Al-containing solid was observed.

AAS

= Atomic adsorption spectroscopy

The Table shows that starting at about 70 ° C there is a sharp increase in Al concentration. This takes at temperatures of 85 to 90 ° C so strong that an insoluble Al connection arises. Therefore, the invention is preferred Process at temperatures from 70 to 100 ° C.

Claims (11)

A process for the preparation of phosphorus-containing alkoxylation by reaction of phosphorus tri- and / or Phosphoroxyhalogeniden with alkylene oxides characterized in that aluminum is used as a catalyst. Method according to claim 1, characterized in that one a) first the phosphorus tri- and / or Phosphoroxihalogenide which continuously reacts with aluminum and b) the reaction product from a) transferred to a reactor and there with the alkylene oxides brings to reaction. Method according to claim 2, characterized in that the step b) c) one Laundry using water or alkali washing followed. Method according to claim 1, characterized in that as alkylene oxide propylene oxide and / or ethylene oxide be used. Method according to claim 1, characterized in that as phosphorus-containing. alkoxylation Tri (chloropropyl) phosphate (TCPP) from phosphorus oxychloride and propylene oxide will be produced. Process according to Claim 5, characterized in that a reaction mixture containing the isomers (I) to (IV) is obtained,

wherein the ratio of isomers (I) / (II) in the mixture is> 2. Method according to claim 1, characterized in that the aluminum in chips, in granulated form, in spherical form or as aluminum lattice. Method according to claim 1, characterized in that the aluminum in cartridges in a Dissolving container is hung. Use of aluminum as a catalyst for the production alkyoxylated, phosphorus-containing compounds. Use according to claim 9, characterized in that as alkoxylated phosphorus-containing Compound tri (chloropropyl) phosphate is produced. Method according to one the claims 1 to 8, characterized in that this at temperatures of 70 to 100 ° C carried out becomes.