DE4425951A1 - Poly:succinimide, poly:aspartic acid and maleamic acid prepn. without extraneous additives - Google Patents

Abstract

Continuous prepn. of polymers (I) with recurring succinyl units comprises: (i) mixing (A) maleic anhydride (II) or its deriv. with (B) NH3 (source) or amides of carbonic acid; (ii) conversion to a low mol. -contg. maleic acid derivs. (III) in a first exothermic reaction stage; and (iii) polymerisation of (III) in a second stage. The novel features are that: (a) stage (i) is carried out adiabatically and the heat of reaction is used to bring the reaction mixt. to the polymerisation temp. and (b) (III) is at least partly polymerised to (I) in stage (iii). Also claimed is a process for continuous prepn. of maleamic acid (IV) by mixing (II) (deriv.) with NH3 (source) rapidly in less than 2 seconds and reaction in a reactor in which the dwell and temp. ensure (almost) no polymerisation. (A) is (II), its derivs. maleic acid and/or fumaric acid; and (B) is NH3, NH4HCO3, (NH4)2CO3 or ammonia salts and amides or carbonic acid. e.g. urea, isourea (ammonium cyanate) carbamic acid and/or ammonium carbamide. Other monomers may be added continuously to (A, B) e.g. alcohols, opt. unsatd. di- and poly-carboxylic acids, unsatd. monocarboxylic acids etc..

Description

The invention relates to a process for the continuous production of polymers with repeating succinyl units, in the case of the maleic anhydride or a derivative thereof (educt A) with ammonia, an ammonia-providing compound or amides of carbonic acid (educt B) are reacted with one another. The Polymers containing PSI can subsequently become aspartic acid-containing polymers be hydrolyzed. By adding co-monomers, copolymers of Polysuccinimide (PSI) can be produced. Furthermore, the invention relates to a continuous Process for the preparation of maleic acid.

The production and use of polyaspartic acid (PAS) and its derivatives has long been the subject of numerous publications and patents.

According to J. Org. Chem., 24, p. 1662-1666, (1959), polysuccinimide, which is referred to there as "anhydropolyaspartic acid" by thermal polycondensation of maleic acid, malic acid monoammonium salt at temperatures obtained up to 200 ° C. The polymer yields were 75% to 79% at 200 ° C. Malic acid, maleic anhydride, Called fumaric acid and asparagine.

Likewise, the production by thermal polycondensation of aspartic acid according to J. Org. Chem. 26, 1084 (1961). It occurs as an intermediate stage first the polysuccinimide (PSI), which is also called "anhydropolyaspartic acid" referred to as. By hydrolysis, PSI can be converted into PAS will.  

US-A 4 839 461 (= EP-A 0 256 366) describes the preparation of polyaspartic acid from maleic anhydride, water and ammonia. Maleic anhydride is in the aqueous medium with the addition of concentrated ammonia solution in the monoammonium salt is converted and then the water from the Solution evaporates. The monoammonium salt is polymerized in bulk. While this polymerization, the mass is first highly viscous and then solid-porous, which requires procedurally complex handling.

From US-A 4 590 260 it is known that amino acids together with derivatives of Malic, maleic and / or fumaric acid are polycondensable at 100 to 225 ° C. According to US Pat. No. 4,696,981, such a reaction can be carried out Use microwaves successfully.

DE-A 22 53 190 describes a process for the preparation of polyamino acid Derivatives, especially polyaspartic acid derivatives, described. After that in addition to aspartic acid, also maleic acid derivatives (monoammonium salt and Monoamide) to the intermediate stage PSI thermally polymerized, which then in suitable solvents with amines to the desired polyamino acid Derivatives can be implemented.

US Pat. No. 5,296,578 describes the production of PSI from maleic anhydride, Water and ammonia. Maleic anhydride becomes maleic acid in water hydrolyzed and then with conc. Ammonia solution in the ammonium salt transferred. The water is evaporated from the solution in a stirred reactor then the monoammonium salt in bulk at temperatures above Polymerized 170 ° C to PSI. The mass is over in several hours Highly viscous phase states converted to the fixed PSI and then hydrolyzed to PAS.

US Pat. No. 5,288,783 describes the production of PAS from maleic acid or fumaric acid, Water and ammonia. Maleic anhydride is mixed with water in a stirred tank mixed and converted to maleic acid with cooling. By adding conc. The maleic acid monoammonium salt is produced in ammonia solution. The water contained is then evaporated and the dry monoammonium salt polymerized at temperatures of 190 to 350 ° C. Alternatively, will  proposed the monoammonium salt present in aqueous solution at temperatures processing from 160 to 200 ° C by extrusion to PSI. The PSI produced using one of the two process routes is then used alkaline hydrolyzed to PAS.

EP-A 593 187 describes the production of PSI by thermal polymerization of maleic acid at temperatures of 160 to 330 ° C with a reaction time from 2 minutes to 6 hours. It is also based on the polycondensation Solvent indicated using condensation aids.

DE-A 42 21 875 describes the production of modified polyaspartic acids through polycondensation and their use as additives for detergents, cleaning agents, Water treatment agent and deposit inhibitor when evaporating of sugars.

This range of PAS applications is already known from other patents. So PAS can be avoided according to EP-A 256 366 (= US-A 4 839 461) and Removal of incrustations by hardening agents ("scale inhibition" and "scale Deposition Removal "). According to US-A 5 116 513, EP-A 391 629 and EP-A 454 126 PAS and their salts are active constituents in washing and cleaning agents. PAS is also used as a bone replacement material in EP-A 383 568 called.

The known processes are initially largely isothermal in stirred tanks Base product for thermal polymerization to PSI and similar substances and then polymerize in bulk at temperatures between 140 and 350 ° C in long times (mostly in several hours) or in solvents. Maleic acid, maleic anhydride, fumaric acid or Maleic acid, as well as water and ammonia are used. As an intermediate PSI production mostly calls the monoammonium salt of maleic acid. The processes described are complex in terms of process technology of handling the viscous phase in thermal polymerization or require non-reactive auxiliaries for thermal polymerization, which subsequently must be removed from product PSI or from PSI hydrolyzed to PAS. Furthermore, these procedures lead to long dwell times due to the handling effort  in the reaction zone. The long thermal load can result in and side reactions, such as. B. lead to decarboxylations. In particular are the proposed methods are energetically unfavorable.

The task was therefore to develop a new process for continuous production to develop polymers with recurring succinyl units, which is procedurally inexpensive, d. H. simple and extensive Use the heat of reaction of the primary reaction step, a fast thermal Polymerization as far as possible while avoiding non-reactive additives, which then have to be separated in a complex manner. In addition, the overall response time should be compared to the prior art significantly reduced and a constant due to the continuous driving style Quality can be guaranteed.

The invention relates to a method for producing polymers recurring succinyl units, in which maleic anhydride or a derivative thereof (educt A) with ammonia, an ammonia-providing compound or Ammonium salts or amides of carbonic acid (educt B) to an N-containing low molecular weight derivative of maleic acid in a first exothermic reaction step converted to an N-containing low molecular weight derivative of maleic acid and this derivative in a subsequent second reaction step is polymerized.

The solution according to the invention to the object stated above is characterized in that that the reaction of the starting materials (A, B) largely in the first reaction step takes place adiabatically and the heat of reaction released is used is to in the second reaction step under the N-containing low molecular weight derivative Obtaining a polymer with recurring succinyl units at least partially to polymerize.

In addition to maleic anhydride, preferred educt A are also maleic acid and fumaric acid or malic acid.

In addition to ammonia, educts B are preferably an ammonia-providing compound, especially ammonium bicarbonate or diammonium carbonate  or ammonium salts and amides of carbonic acid such as urea, isourea (Ammonium cyanate), carbamic acid or ammonium carbamide. These Educts can be used individually or in mixtures in bulk or solution will.

Maleic anhydride or its derivatives are used in a preferred embodiment used as a melt.

The reaction of the starting materials can optionally in the presence of a solvent be performed. Suitable solvents are water, polar aprotic Solvents such as dimethylformamide, N-alkyl pyrrolidone, sulfolane, acetone etc. Polyalkylene glycols, polyalkylene glycol monoalkyl ethers and polyalkylene glycol dialkyl ethers. Supercritical gases such as e.g. B. carbon dioxide. Especially water is suitable.

In a preferred embodiment, the starting materials are molten maleic anhydride (Educt A) and ammonia solution, especially an aqueous ammonia solution (Educt B).

Maleic anhydride or derivatives thereof are preferably used as starting material A in such amounts are used that the molar ratio of nitrogen in the educt B relative to the maleic anhydride or a derivative thereof in the starting material A between 0.1 and 5.0, preferably between 0.5 and 4.0 and very particularly preferably between 0.9 and 3.0.

The first reaction step is a quick reaction, in the consequence of which is unspecific Reaction management by parallel and subsequent reactions undesirable by-products can arise.

Reduction of unwanted by-products in complex reaction systems of many parallel and follow-up reactions through the micromixing of the Educts, which must happen faster than the reactants react with each other, are in known in the literature (Ullmann: Encyclopedia of Industrial Chemistry, 1992, Vol. B2, Chap. 24; J.R. Bourne, H. Maire: Chem. Eng. Process 30 (1991) 23-30).  

Are the chemical reaction rates and the mixing rates of the educts of the same order of magnitude, there is one complex interaction between the reactions and the local, from the Turbulence determined mixing behavior in the reactor and on the mixing element. If the reaction speeds are even much faster than the mixing speeds, so the yields become clear through the mixing, i.e. H. by the local speed and concentration field of the reactants and thus influenced by the reactor design and turbulence structure (see e.g. R. S. Brodkey, Turbulence in Mixing Operations - Theory and Application to Mixing and Reaction, Academic Press, N.Y. 1975).

Suitable devices for mixing two liquid streams sufficiently quickly are known from many references and patents (e.g. Ullmann: Encyclopedia of Industrial Chemistry, 1982, Vol. B2, Chap. 25; Vol. B4, 561-586; Perry's Chemical Engineers Handbook, 6th ed. (1984), Mc-Graw-Hill, N.Y., 21-61; M. H. Pohl, E. Muschelknautz, Chem. Ing. Tech. 51: 347-364 (1979); Chem. Ing. Tech. 52: 295-291 (1980).

Preferred devices for rapid mixing of the educt streams are all types of

• a) jet mixers,
• b) static mixers,
• c) dynamic mixers.

Particularly preferred devices for the rapid mixing of the educts and to start the exothermic reaction are jet mixers, the others Advantages with hermetic tightness, the variably adjustable mixing energy and the global plug-flow characteristics.

In a preferred embodiment, the starting materials are carried out the 1st reaction step to avoid undesirable side reactions mixed in a fast mixing apparatus of the above type and the exothermic formation of the intermediate products is carried out in parallel or thereafter.  

The heat released is in the educt-intermediate mixture in the essentially saved. This brings the reaction mixture to the polymerization temperature brought and optionally the organic solvent or all or at least part of the water and water formed during the reaction evaporates.

In a particularly preferred embodiment, the mixing takes place in <2 s and the exothermic formation of the intermediates in less than 60 s.

The reaction mixture emerging from the first reaction stage is then brought to polymerization in a suitable apparatus.

In principle, all apparatuses suitable for thermal polymerization are suitable for a narrow residence time distribution of the viscous liquid phase the necessary minimum residence time for polymerization and at the same time an at least partial evaporation of the solvent, especially water, and that in the reaction enable water formed.

In the known PSI production from maleic acid or a derivative thereof Ammonia, gaseous or liquid, urea, isourea, ammonium cyanate, Carbamic acid, ammonium carbamide, ammonium hydrogen carbonate, diammonium carbonate and mixtures of the aforementioned substances in substance or in solution, especially in aqueous solution, a complex reaction system with many arises Parallel and follow-up reactions. To maximize product yield and thus to reduce unwanted polymer components in such complex reaction system with undesirable parallel and subsequent reactions it is known in principle that the micromixing of the starting materials takes place more quickly must react as the reactants with one another (e.g. K. H. Tebel, H.-O. May: Chem.- Ing.-Tech. 60 (1988) and MS 1708/88; J.R. Bourne, H. Maire: Chem. Eng. Process. 30 (1991) pp. 23ff; R. S. Brodkey: Chem. Eng. Commun. 8 (1981) pp. 1ff).

Furthermore, should build up polymer chains with uniform chain length thermal polymerization, if possible, in the same residence time for all molecules be carried out under identical reaction conditions as possible. Suitable  Reactors with a narrow residence time spectrum are known in the relevant literature (e.g. Ullmann: Encyclopedia of Industrial Chemistry, 1992, Vol. B4, 97-20).

Preferred devices for thermal polymerization are all devices, which have a defined dwell time with a narrow dwell time distribution for the fixed or have a highly viscous phase and at the same time good temperature control by at least partially evaporating the solvent (organic solvent and / or water) and / or the water of reaction formed in the polymerization enable. Such preferred devices can be, for example

• a) indwelling tubes,
• b) high-viscosity reactors (e.g. screw, list reactor),
• c) dryer (e.g. paddle dryer, spray dryer),
• d) cascade of stirred tanks,
• e) thin film evaporator,
• f) Multi-phase spiral tube reactors (MPWR) (DE 16 67 051, DE 2 19 967).

Particularly good results are achieved if the starting materials (A, B) are a jet mixer are supplied, which is followed by a tubular reactor or an MPWR. This combination of devices has been used to implement the invention Proven procedure.

To check the reactor temperature of the reactions carried out, a complete or partial circulation of the reaction mixture in combination with heat dissipation. Are particularly suitable for such a reaction all reactors of the above type with recycling of the reaction mixture in combination with heat dissipation and all loop reactors.

In a further variant of the method according to the invention can be avoided a rapid and strong rise in temperature of the reaction mixture due to the very exothermic rapid maleic acid formation reaction Educt component at several points in a suitable manner along the pipe or Multi-phase spiral tube reactor are metered in, so that an optimal temperature profile can be achieved. This prevents the occurrence of  Temperature peaks (excess temperatures) occur, which lead to product damage can. The number of additional (without dosing in the mixing nozzle on Tube or multi-phase spiral tube reactor inlet) metering points is preferably in Range of up to 10. The type of feed is chosen so that a good Mixing with the reaction solution takes place.

The mixing of the starting materials can, depending on the starting materials used, at temperatures between 0 ° C and 200 ° C. The exothermic adiabatic reaction of the The first reaction step then provides enough heat that the second reaction step then depending on the type and concentration of the starting materials used at 120 to 500 ° C, preferably at 140 to 450 ° C and particularly preferably at 140 to 400 ° C can take place. The temperature over the pressure in the reactor and is advantageous the volume flows of the starting materials (A, B) and the organic content Solvent and / or water adjusted. To support temperature control cooling and heating media can also be used during the reaction will. Furthermore, product educt areas with different temperatures directly or indirectly in contact in the reaction system for the purpose of heat exchange to be brought.

The residence times of the abovementioned starting materials in the reactor system described earlier are up to 120 minutes. Residence times of up to are preferred 30 minutes. Decreasing with increasing temperature are particularly preferred Dwell times, d. H. at temperatures between 120 and 200 ° C less than 30 Minutes; at temperatures between 200 to 250 ° C less than 10 minutes; at Temperatures between 250 to 300 ° C less than 5 minutes; at temperatures above 300 ° C less than 2 minutes.

The residence time in the reactor system is preferably chosen so that a practical complete implementation of the starting material A used in the deficit, preferred MSA, is guaranteed. It may be necessary for virtually complete polymerization shortly after mixing in the first reaction zone, particularly preferably in a tubular reactor, monomer and oligomer mixture obtained into another device proposed above, preferably one High viscosity reactor to implement. However, it is particularly preferred to use one High-viscosity reactor can be dispensed with and it already works in an indwelling tube,  preferably in an MPWR, complete PSI formation. The received Reaction products are depending on the water or solvent content because of the released Enthalpy of reaction hot solutions or solvent-based or water-containing Melt. The enthalpy of reaction can largely be used in the reactor will. This ensures optimal heat management with low investment and operating costs a process engineering plant that leads to high economic efficiency.

When using the PSI oligomer-containing melts in a high-viscosity reactor can the reaction rate in a preferred reaction in Contrary to direct synthesis from the educts maleic acid ammonium salt or Maleic acid in such a device through the already preheated and due to the heat of reaction released partially by evaporation on solvent impoverished viscous mass can be increased significantly. The dwell time is significantly reduced by this procedure compared to the prior art.

The polymers produced by the process according to the invention have recurring Succinyl units with one of the following structures:

In addition, other reactions can be carried out by appropriate reaction management and choice of the starting materials recurring units may be included, e.g. B.

a) Malic acid units of the formula  

b) Maleic acid and fumaric acid units of the formula

The chemical structure is preferably analyzed with 13 C-NMR, FT-IR and after total hydrolysis with HPLC, GC and GC / MS.

According to a further development of the invention, the structure of the obtained Polysuccinimide can be influenced by the stoichiometric ratio of the starting materials. In particular, the educts maleic anhydride and ammonia a molar excess of ammonia, a polymer is obtained with recurring succinyl units:  

Preferably 1.8 to 25.0 per mol of maleic anhydride are preferred 2.0 to 10.0 mol, particularly preferably 2 to 5 mol, of ammonia are used.

The polymerization products can optionally be reacted with a base be converted into a PAS-containing salt in the presence of water. This conversion from PSI-containing to PAS-containing polymers then happens in a suitable device by hydrolysis. A pH value is preferred suitable between 5 and 14. A pH value is in a particularly preferred form from 7 to 12 g, especially by adding a base. Suitable bases are alkali and alkaline earth metal hydroxides or carbonates such as sodium hydroxide solution, Potash lye, soda or potassium carbonate, ammonia and amines such as triethylamine, Triethanolamine, diethylamine, diethanolamine, alkylamines etc.

The temperature in the hydrolysis is suitably in a range including up to the boiling point of the PSI suspension and preferably at 20 to 150 ° C. The hydrolysis is optionally carried out under pressure.

However, it is also possible, by purely aqueous hydrolysis or treatment of the Salt with acids or acidic ion exchangers to free polyaspartic acid receive. The term "polyaspartic acid" (= PAS) in the present context  Invention also the salts, unless expressly stated otherwise. The finished Product is obtained by drying, preferably spray drying.

Depending on the reaction conditions, the polymer produced shows for example, residence time and temperature of the thermal polymerization differ Chain lengths or molecular weights according to gel permeation chromatography Analyzes (Mw = 500 to 10,000, preferably 700 to 5,000, especially preferably 1,000 to 4,500). In general, the proportion of the beta form is included more than 50%, preferably more than 70%.

The polyaspartic acids according to the invention can be added in low-phosphate and phosphate-free detergents and cleaning agents can be used. The polymers are builders for detergents and work during the washing process a reduction in incrustation and graying on the washed textile.

Furthermore, the polyaspartic acids according to the invention are water treatment agents suitable. You can use the water in cooling circuits, evaporators or seawater desalination plants. They can also be used as Anti-scale agents can be used for the evaporation of sugar juice.

Because of their good dispersing properties, the inventive ones are suitable Polyaspartic acids also as dispersants for inorganic pigments and Production of highly concentrated solid dispersions (slurries).

Another object of the invention is the production of modified polyaspartic acids, at which one

• a) 0.1-99.9 mol% of the aforementioned educts
• b) 99.9-0.1 mol%

of fatty acids, fatty acid amides, polybasic carboxylic acids, their anhydrides and amides, polybasic hydroxycarboxylic acids, their anhydrides and amides, Polyhydroxycarboxylic acids, aminocarboxylic acids, sugar carboxylic acids, alcohols, Polyols, amines, polyamines, alkoxylated alcohols and amines, amino alcohols,  Amino sugars, carbohydrates, ethylenically unsaturated mono- and Polycarboxylic acids and their anhydrides and amides, protein hydrolyzates such. B. Corn protein hydrolyzate, soy protein hydrolyzate, aminosulfonic acids and aminophosphonic acids according to the inventive method described above for Brings reaction.

The starting materials described under a) are in the polymerization according to the invention 0.1 to 99.9 mol%, preferably 60 to 99.9 mol% and particularly preferably from 75 to 99.9 mol%.

All fatty acids can be considered as component (b) of the polymers. They can be saturated or ethylenically unsaturated. Examples are formic acid, Acetic acid, propionic acid, butyric acid, lauric acid, palmitic acid, stearic acid, Oleic acid, linoleic acid, linolenic acid, sorbic acid, myristic acid, undecanoic acid as well as all naturally occurring fatty acid mixtures, for example C₁₂ / C₁₄- or C₁₆ / C₁₈ fatty acid mixtures. Acrylic acid can also be used as unsaturated fatty acids and methacrylic acid can be used.

Furthermore, these acids can also be used in the form of their amides. As polybasic carboxylic acids can, for example, oxalic acid, succinic acid, glutaric acid, Adipic acid, malonic acid, suberic acid, aconitic acid, itaconic acid, sulfosuccinic acid, Alkenyl succinic acids (C₁-C₂₆), 1,2,3-propane tricarboxylic acid, Butane tetracarboxylic acid, furandicarboxylic acid, pyridinedicarboxylic acid can be used. The anhydrides of polybasic carboxylic acids such. B. succinic anhydride, Itaconic anhydride, aconitic anhydride and phthalic anhydride be used. Coming in as component (b) are also polybasic Hydroxycarboxylic acids and polyhydroxycarboxylic acids into consideration. Polybasic In addition to at least one hydroxy group, hydroxycarboxylic acids carry at least one two or more carboxyl groups. Examples include malic acid, tartaric acid, Called grape acid, citric acid and isocitric acid.

Monobasic polyhydroxycarboxylic acids carry two in addition to one carboxylic acid group or more hydroxy groups, e.g. B. glyceric acid, dimethylol propionic acid, dimethylol butyric acid, Gluconic acid. In addition, monohydric alcohols are included, for example 1 to 22 carbon atoms such as B. methanol, ethanol, n-propanol, i-propanol,  Butanol, pentanol, hexanol, octanol, lauryl alcohol, stearyl alcohol etc. suitable. The alcohols can also optionally have a double bond, such as allyl alcohol or oleyl alcohol. These alcohols can also be alkoxylated be, for example with ethylene oxide or propylene oxide. From technical The adducts of 3 to 50 mol ethylene oxide with fatty alcohols are of particular interest or oxo alcohols. Furthermore, as component (b), polyols can either saturated or unsaturated, such as. B. ethylene glycol, propylene glycol, Butanediol, butenediol, glycerol, trimethylolpropane, pentaerythritol, Sorbitol, neopentyl glycol and alkoxylated polyols such as polyethylene glycols, polypropylene glycols, with ethoxylated trimethylolpropane, glycerin or pentaerythritol Molecular weights up to 6000 can be used. Furthermore are suitable as Comonomer (b) also amines such as C₁-C₂₂ alkylamines, e.g. B. methylamine, ethylamine, Propylamine, butylamine, cyclohexylamine, octylamine, isooctylamine (ethylhexylamine), Stearylamine, allylamine, oleylamine, ethylenediamine, diethylenetriamine, Hexamethylene diamine, piperazine, diaminobutane, dimethylamine, diethylamine, Hydroxylamine, hydrazine, ethanolamine, diethanolamine, aminopropanediol, and Polyalkylene amines such as polyethylene amine with molecular weights up to 6000. Die Amines can also be alkoxylated, e.g. B. the addition products from 3 to 30 mol ethylene oxide to fatty amines such as oleylamine, palmitylamine, or stearylamine. Aminosugars such as aminosorbitol or chitosamine are also suitable. In addition, as component (b) carbohydrates such as glucose, sucrose, maltose, Dextrins, starch or sugar carboxylic acids, for example mucic acid, gluconic acid, Glucuronic acid, glucaric acid. In addition, amino acids, proteinogens such as glycine, alanine, glutamic acid and lysine or non-proteinogens such as 4- Aminobutyric acid, diaminosuccinic acid, 11-aminoundecanoic acid and 6-aminocaproic acid can be used as component (b). The connections of the component (b) are in amounts of 0.1 to 99.9 mol%, preferably 0.1 to 40 mol%, particularly preferably 0.1 to 25 mol%, are used for the polymerization. One can use a single compound of component (b) or mixtures use two or more connections from (b). The connections of the component (b) can in the desired ratio with one of the main educts (a) are mixed and used as a mixture in the first reaction stage.

In another embodiment, the compounds of component (b) the reaction mixture shortly after the mixing of the main starting materials (a) in one  added early stage of polymerization. The connections are also possible component (b) simultaneously with the main educts (a) into the mixer system meter in.

If monofunctional compounds such as alcohols, amines, Fatty acids or fatty acid amides are used, so they are installed at the chain end. They act as chain terminators and lower the molecular weight. Multifunctional Compounds of component (b) can both in the finished polymer installed at the chain end as well as statistically distributed over the polymer chain his.

The crude polymers can be processed, for example, by customary workup methods by extraction with water and 1N hydrochloric acid or by membrane filtration of monomeric parts are exempt. The copolymers are analyzed by ¹³C and ¹⁵N NMR spectroscopy, FT-IR spectroscopy and after total hydrolysis with HPLC, GC and GC-MS. This occurs in the polymerization according to the invention Polymer primarily in the form of the mostly water-insoluble modified polysuccinimides at.

The modified polyaspartic acids are preferably derived from the polysuccinimides by aqueous hydrolysis at 20 ° C to 150 ° C and pH 7 to 12, optionally manufactured under pressure. This reaction can also be found in Temperatures outside the specified temperature range and at other pH Perform values. Suitable bases are alkali and alkaline earth metal hydroxides or Carbonates such as sodium hydroxide solution, potassium hydroxide solution, soda or potassium carbonate, Ammonia and amines such as triethylamine, triethanolamine, diethylamine, diethanolamine, Alkylamines etc. Partially or completely neutralized copolymers are obtained, the 0.1 to 99.9 mol% aspartic acid and 99.9 to 0.1 mol% of contain at least one compound (b) in copolymerized form.

Become primary amines or bases bearing primary amino groups for hydrolysis used, the resulting amine salts by dehydration in the corresponding amides are converted. The elimination of water can Annealing at temperatures from 30 ° C to 250 ° C, optionally supported by Vacuum.  

The modified polyaspartic acids prepared by the process according to the invention according to the "OECD Guidelines for testing of chemicals (1981)" as classified as biodegradable.

The modified polyaspartic acids according to the invention can be added as Low-phosphate and phosphate-free detergents and cleaning agents are used will. The polymers are builders for detergents and act during the Washing process a reduction in incrustation and graying on the washed textile.

Furthermore, the modified polyaspartic acids according to the invention are water treatment agents suitable. You can use the water in cooling circuits, evaporators or seawater desalination plants. You can also they are used as deposit inhibitors in the evaporation of sugar juice.

Because of their good dispersing properties, the inventive ones are suitable modified polyaspartic acids also as dispersants for inorganic pigments and for the production of highly concentrated solid dispersions (slurries).

The invention further relates to a process for the production of maleic acid, characterized in that maleic anhydride or a derivative thereof (Educt A) with ammonia, an ammonia-providing compound (educt B) in a fast mixing apparatus with a mixing time <2 s, preferably in a jet mixer, mixed and in a subsequent reactor are implemented, the residence time and the temperature being chosen so that no or almost no polymerization takes place.

It is already known that maleic acid can be obtained by reacting maleic anhydride can be prepared with ammonia in inert solvents. So you get Maleic acid by introducing ammonia into a solution of maleic anhydride in xylene, ethylene chloride, tetralin or dioxane at 50 to 100 ° C and isolating the precipitated amic acid by filtration (US 2 459 964 / DE 8 47 287 / JP 49 035 325 / C. K. Sauers, R. J. Cotte, J. Org. Chem., 26.6 (1961). This solvent process have the disadvantage that because of the high heat of reaction in  dilute solution must be worked, what the separation, workup and Recycling of larger amounts of solvent. requirement for this process is furthermore that the maleic anhydride no maleic or Fumaric acid contains the solvent used and the ammonia gas absolutely are dry and that work is carried out with the exclusion of moisture. Disadvantageous this procedure also has the effect that it is at the point of initiation of the Ammonia gas to form crusts and clog the inlet pipe can.

In German Patent No. 9 45 987 a method is described in the maleic anhydride with ammonia in the presence or absence of Water is converted to maleic acid. A variant is powdered Maleic anhydride in a chilled 21% aqueous ammonia solution to be entered. This has the disadvantage that during the addition and reaction of must be cooled externally, otherwise there will be a noticeable hydrolysis of the MSA, but the yield losses are considerable even below 10 ° C. The aqueous solution of the ammonium salt of maleic acid (by-product) must be isolated the maleic acid can be worked up. Another variant is the Fumigation of powdered maleic anhydride with ammonia. Here must for good mixing must be ensured, which in gas-solid reactions with considerable technical problems are connected; the gas introduction must be relatively slow take place and it must also be cooled from the outside. The maleic anhydride must be used in finely powdered form, which is hygienic is not harmless.

The Soviet patent SU 362 821 describes the conversion of maleic anhydride with ammonia in a homogeneous vapor phase at temperatures of 215 to 350 ° C in the absence of solvents and contact times from 0.2 to 1.0 s. The maleic acid is only obtained in approx. 70% purity, so that to achieve pure product an expensive post-cleaning with losses and contaminated waste water becomes necessary.

The starting materials are preferably mixed and at a temperature of 20 ° C to 250 ° C, preferably from 60 ° C to 200 ° C, to maleic acid implemented. The maximum temperatures are preferably exceeded by  Relaxation and rapid cooling of the reaction mixture prevented. In a preferred embodiment, the starting materials are molten maleic anhydride and an aqueous ammonia solution or ammonia dissolved in one organic solvents. The residence time in the reactor is 0.1 to 200 s, preferably 0.1 to 60 s. These educts are again advantageous fed to a jet mixer, which is followed by a reactor.

It must be described as extremely surprising that maleic acid by atomizing and quickly mixing the starting components with MSA especially aqueous ammonia solution in quantitative yield and high purity can be obtained, it is known that maleic acid in the presence of Water already at low temperatures with the formation of the ammonium salt Maleic acid hydrolyzed. The fast mixing in connection with the high Reaction rate to maleic acid and rapid cooling of the Reaction mixture leads to the fact that atomized MSA does not lead to the water Maleic acid hydrolyzed.

The following advantages are achieved with the invention:
The process according to the invention enables the simple production of maleic acid in high yield and purity. The process can be carried out technically without great effort; subsequent cleaning steps are not necessary; the use of organic solvents that have to be reprocessed is eliminated.
The technical implementation allows a high throughput, the energy costs due to external heating or cooling are minimized, which leads overall to a significantly improved economy of the process.
The maleic acid produced by the process according to the invention can serve as a starting material for the production of polysuccinimide (J. Org. Chem., 24, 1662-1666 (1959)), which in turn is a valuable starting material for polyaspartic acid and its salts. The latter are widely used as detergents, dispersing and formulation aids.
Maleic acid is also used as a starting material for alkyl-β-cyanoacrylate (J. Org. Chem. 26, 6 (1961)), which in turn has a variety of uses, for. B. as active ingredient intermediates (US 2,437,231, US 2,531,408, US 2,850,486 and US 2,850,487).

The invention is described below using exemplary embodiments and drawings explained in more detail.

It shows

Fig. 1 is a process scheme for the preparation of polysuccinimide substantially adiabatic,

Fig. 2 is a process diagram for the production of polyaspartic acid,

Fig. 3 shows a process scheme for the production of maleic acid.

According to Fig. 1, consisting of maleic anhydride or a derivative of maleic anhydride reactant A is fed to a jet mixer 2 with a downstream tubular reactor 3 via the dosing pump 1. The starting materials A, B can also be interchanged on the jet mixer 2 . At the same time, the educt B is injected into the jet mixer 2 with the aid of the metering pump 4 . At the nozzle outlet, the starting materials A, B are mixed intensively. At the same time, the exothermic reaction between the starting materials A, B is started. This reaction then continues in the tube reactor 3 following downstream, a nitrogen-containing low-molecular derivative of maleic acid being formed in the first reaction step. The heat of reaction released in this reaction step is now used to polymerize the nitrogen-containing low-molecular-weight derivative to a polymer with recurring succinyl units in a second immediately subsequent reaction step, which also takes place in tubular reactor 3 . The starting materials are mixed in the jet mixer 2 and the exothermic reaction takes place so quickly in the first reaction step that essentially no heat is released into the environment; ie the reaction to the nitrogen-containing low molecular weight derivative of maleic acid is largely adiabatic. The polymer obtained, e.g. B. polysuccinimide, can be fed directly to the spray reactor 5 for drying after the tubular reactor 3 , at the discharge 7 the finished free-flowing product is withdrawn. Steam and gas are discharged through the nozzle 6 . Orifices 8 or other resistors for determining the reaction pressure can be installed in the tubular reactor 3 . The reaction temperature for given starting materials can be precisely controlled by means of the pressure and, if necessary, an additional trace heating or cooling. In addition, the tubular reactor 3 can be equipped in the manner of a loop reactor with a return line 9 which has a feed pump 10 and a heat exchanger 19 . In the return line 9 , further solvent (water, organic solvent or supercritical gas such as CO₂) can optionally be metered in to lower the viscosity of the mixture. Instead of a tubular reactor 3 , an MPWR can be used in a preferred variant of the method according to the invention.

Another variant of the process is that the reaction conditions, in particular the temperature and the residence time in the tubular reactor 3, are set such that the product emerging from the tubular reactor 3 has not yet been completely polymerized. The residence time in the tubular reactor can essentially be set via the flow rate (throughput), the slope of the coiled tubing at the MPWR and over the total length of the tubular reactor, while the temperature is expediently via the reactor pressure and / or cooling / heating medium and / or the solvents to be evaporated - / amount of water is set. If the polymerization is incomplete, the reaction product in this process variant can be fed via line 11 to a high-viscosity reactor 12 and polymerized there completely. The pasty or powdery product emerging from the high-viscosity reactor is then optionally subsequently dried in a known manner (dryer 13 ). As a high viscosity reactor z. B. used a continuously operated, self-cleaning and equipped with hollow shafts constant twist worm machine. In this process variant, the reaction conditions are expediently set such that the product emerging at the tubular reactor 3 or MPWR is converted to a prepolymer of 5 to 95%, preferably at least 20%, particularly preferably greater than 50%. The polymerization is then completed in the high-viscosity reactor 12 .

Water or an organic solvent or a supercritical gas such as CO₂ can be used as a solvent for the nitrogenous starting material B, which largely evaporates due to the exothermic nature of the first reaction step in the tubular reactor 3 or MPWR. The reaction can easily be carried out so that 50 to 99% of the solvent (water, organic solvent or supercritical gas such as CO₂) evaporate in the tubular reactor 3 or MPWR. The reaction temperature in the tubular reactor 3 or MPWR can be set via the solvent content and the pressure.

The polysuccinimide produced by the process according to FIG. 1 can be further hydrolyzed to polyaspartic acid by the process shown in FIG. 2. To this end, the fully polymerized product from the tubular reactor 3 and MPWR is passed directly into a suitable hydrolyzer 14, while in process variant with an incomplete polymerization of the light emerging from the high-viscosity reactor 12 product is conveyed in the above-mentioned apparatus fourteenth The hydrolysis is carried out in the above-mentioned device 14 in a known manner by adding a base C at temperatures between 20 ° C. and the boiling point of the suspension containing polyaspartic acid, optionally under pressure. A preferred embodiment of the hydrolysis device 14 is a pump-around reactor with external / internal heat exchangers 21 for good temperature control and gentle hydrolysis of the polymers with recurring succinyl units. The circulation of the base-containing product solution can be fed into the end piece of the tubular reactor or MPWR for intensive mixing. The base is preferably fed in on the suction side of the circulation pump 20 suitable for intensive mixing. The finished polyaspartic acid is drawn off at the outlet 15 of the above-mentioned device 14 and, if appropriate, fed to a post-reactor. It is then dried in a downstream spray dryer 16 .

In the method of Fig. 3 is a similar procedure is used to prepare maleamic acid. The reaction conditions in the reactor 17 are deliberately chosen so that at most a small proportion of the starting materials A, B polymerize. In practice, the procedure is such that the reactor 17 is made shorter and cooled (external and / or evaporative cooling) in order to prevent the polymerization. The reaction product (maleic acid) is similar to the first-described process variant according to FIG . B. dried in a spray dryer 18 .

The process parameters and reaction conditions observed in the processes according to FIGS. 1-3 are further explained below using the exemplary embodiments.

Examples

The following examples were carried out in a reactor system which consisted of a jet mixer 2 of the smooth jet nozzle type and a subsequent tubular reactor 3 or MPWR. The thermal polymerization was optionally ended in a downstream, continuously operated, self-cleaning co-rotating screw machine 12 equipped with hollow shafts. In the examples, molten maleic anhydride was injected into a 25 or 50% strength by weight ammonia solution using a smooth jet nozzle and quickly mixed into the tube reactor 3 or MPWR. Tube reactors of various lengths with an inner tube diameter of 15 mm were fitted with an orifice 8 at the tube end in order to be able to control the reactor pressure via the pressure drop. Due to the design, the reactor pressure is approximately the same as the ammonia pressure during dosing. Behind the orifice 8 , the reaction mixture relaxed to normal pressure and flowed through an indwelling tube either into the screw machine 12 for thermal polymerization or directly into the hydrolysis tank 14 connected downstream.

Example 1

It was melted MSA at 80 ° C through a 0.4 mm smooth jet nozzle Nozzle cross section mixed with 8 ° C cold 25% by weight aqueous ammonia solution and metered into the downstream tubular reactor. After a reaction space length A diaphragm with an inner diameter of 10 cm was used for pressure maintenance of 0.75 mm screwed into the pipeline. The reaction room was followed by a 1 m long dwell pipe. The MSA melt was with a mass flow of 15.7 kg / h at 28 bar through the smooth jet nozzle in the Reaction space pressed. The aqueous ammonia solution was at 20 bar 11.4 kg / h metered into the reaction space. The temperature in the reaction space was 110 to 180 ° C. When relaxing behind the bezel, little was left Water evaporates so that there is only a slight drop in temperature came. The viscous pre-concentrated by already partially evaporating water The liquid mixture was then at 170 to 175 ° C on a heatable, twin-shaft co-rotating screw machine with a dwell time of 10 minutes  polymerized. It became a coarse-grained to powdery pink to orange Received product.

The analysis results are summarized in Table 1.

Example 2

Again, the tubular reactor provided with a smooth jet nozzle as a jet mixer used. It was melted MSA at 85 ° C through a smooth jet nozzle with 0.7 mm nozzle cross-section with 6 ° C cold 25% by weight aqueous Ammonia solution mixed and metered into the tube reactor. After a reaction space length The diaphragm with an inner diameter of 6 cm was used for pressure maintenance 0.75 mm in the pipeline. The downstream of the reaction space Dwell pipe was shortened to 40 cm. The residence time in the reaction space was about 0.4 s. With the shortened indwelling tube after the Reaction space, the total residence time was only about 1.6 s. The MSA The melt was passed through the at a mass flow of 45.8 kg / h at 36 bar Smooth jet nozzle pressed into the reaction space. The aqueous ammonia solution was metered into the reaction space at 30 bar at 34.3 kg / h. The temperature in Reaction space was about 185 ° C. When relaxing behind the bezel it happened by evaporating water to bring the temperature down to about 135 ° C. The viscous liquid mixture pre-concentrated in this way became then again at 170 to 175 ° C on a heatable, double-shaft Co-rotating screw machine polymerized with a residence time of 10 minutes. It also became a coarse-grained to powdery pink to orange Received product. The analysis results are in Table 1 summarized.

Example 3

The experiment was carried out in the same apparatus and under the same conditions performed as example 1.

It was melted MSA at 75 ° C through a 0.4 mm smooth jet nozzle Nozzle cross section mixed with 7 ° C cold 25% by weight aqueous ammonia solution  and dosed into the tubular reactor. After a reaction chamber length of 10 cm an orifice with an inner diameter of 0.75 mm in screwed the pipeline. A 1 m long pipe used. The MSA melt was with a mass flow of 12.8 kg / h at 25 bar through the smooth jet nozzle into the reaction chamber. The aqueous ammonia solution was at 20 bar at 17.7 kg / h in the reaction chamber dosed. The temperature in the reaction space and after relaxation was also 110 to 180 ° C. This by already partially evaporating Water pre-concentrated viscous liquid mixture was then directly at 170 to 175 ° C on the heatable, double-shaft co-rotating screw machine polymerized with a residence time of 10 minutes. It was a coarse-grained orange solid obtained.

The analysis results are summarized in Table 1.  

Analytics

Table 1

The structure of the polymerization products prepared in Examples 1-3 was examined by 13 C-NMR and FT-IR. It was found that the Products made in Examples 1 and 2 mainly from polysuccinimide consist. A minor component was polyaspartic acid found. In Example 3, the product consisted predominantly of polyasparagine and contained only minor amounts of polysuccinimide. Through an alkaline hydrolysis However, polyaspartic acid Na salt can be produced from it. A GPC Analysis of the hydrolysis product showed an average molecular weight of 2900.

Example 4

Again, the tubular reactor provided with a smooth jet nozzle as a jet mixer used. It was melted MSA at 82 ° C through a smooth jet with 0.7 mm nozzle cross section with 9 ° C cold 50 wt.% aqueous Ammonia solution mixed and metered into the tube reactor. After a reaction space length A diaphragm with an inner diameter of 15 cm was used for pressure maintenance of 0.9 mm used in the pipeline. The downstream indwelling tube was 40 cm long. The MSA melt was with a mass flow of 44.4 kg / h at 72 bar through the smooth jet nozzle into the reaction chamber. The aqueous ammonia solution was at 65 bar at 14.8 kg / h in the reaction chamber dosed. The temperature in the reaction chamber was 250 to 275 ° C. When relaxing behind the screen there was a vaporization of water Temperature drop to about 230 ° C. The viscous obtained in this way Liquid was a yellow-orange aqueous melt solution which was viscous at 140 ° C plastically solidified on cooling to room temperature. An analysis of this Melting solution showed that a clear polymerization had already taken place would have. According to GPC measurement, the average molecular weight Mw was 1150 found.

The melt solution was then re-polymerized at 170 up to 175 ° C on a heatable, double-shaft co-rotating screw machine polymerized with a residence time of 10 minutes. It was also a Powdery, pink to orange product obtained.

The analysis results are summarized in Table 1.  

Example 5

Again, the tubular reactor provided with a smooth jet nozzle as a jet mixer used. It was melted MSA at 70 ° C through a smooth jet with 0.7 mm nozzle cross-section with 5 ° C cold 50% by weight aqueous Ammonia solution mixed and metered into the tube reactor. After a reaction space length of 50 cm was now an aperture with a Inside diameter of 1.1 mm inserted in the pipeline. The indwelling tube after the reaction space again had a length of 40 cm. The MSA The melt was passed through the at a mass flow of 50.2 kg / h at 68 bar Smooth jet nozzle pressed into the reaction space. The aqueous ammonia solution was metered into the reaction space at 58 bar at 15.7 kg / h. The temperature in Reaction space was 320 to 340 ° C. When relaxing behind the bezel came it by evaporating water to bring the temperature down to about 260 ° C.

The hot mixture was fed into a cooled feed tank with a volume of 50 l. An orange-red melt solution was obtained, which after a GPC measurement has an average molecular weight Mw of 1700. By adding water a light red solid is filled out from this melt solution and separated, which consists of PSI. The average molecular weight was 2,700 The polysodium salt obtainable by alkaline hydrolysis already shows good sequestering and dispersing properties, so that for at least some Applications to postpolymerization in a high viscosity reactor can be. The analysis results are summarized in Table 1.

Example 6

In this example we used a smooth jet nozzle as a jet mixer provided MPWR without downstream high-viscosity reactor used. It was melted MSA at 100 ° C via a smooth jet nozzle with a 0.35 mm cross section mixed with 7 ° C cold 40 wt .-% aqueous ammonia solution and dosed into the MPWR. After a reaction chamber length of 290 cm Pressure maintenance now an aperture with an inner diameter of 2.1 mm in the Pipe of the MPWR used. An indwelling tube with a length of 40 cm leads  from the MPWR to a downstream 50 l stirred tank in which 20 kg of water be presented. The MSA melt was at a mass flow of 25.4 kg / h at 40 bar through the smooth jet nozzle into the reaction chamber. The aqueous ammonia solution was at 16.5 bar at 11.0 kg / h in the reaction chamber dosed. The temperature in the reaction space was 220 to 235 ° C. In the Relaxation behind the aperture came from the evaporation of water only to lower the temperature to around 210 ° C. The hot mixture was passed into the storage tank at a temperature of 60 ° C. and it became 45% by weight Sodium hydroxide solution metered in, the pH value being regulated at about 9.5 was held. An orange-red aqueous PAS solution is obtained. The isolated one Solid, polyaspartic acid sodium salt, has a medium according to GPC measurement Molecular weight Mw of 3000. The product shows good sequestering and Dispersing properties.

Example 7

Again, the one with a smooth jet nozzle was used as a jet mixer Tube reactor used without a downstream high-viscosity reactor. It was melted MSA at 130 ° C via a smooth jet nozzle with a 0.35 mm nozzle cross section mixed with a 90 ° C hot 75 wt.% aqueous urea solution and dosed into the tubular reactor. After a reaction chamber length of An aperture with an inner diameter became 290 cm for pressure maintenance of 2.1 mm in the pipeline. An indwelling tube with a length of 40 cm leads to a downstream 50 l stirred tank in which 20 kg of water be presented. The MSA melt was at a mass flow of 25.4 kg / h (259 mol / h) at 40 bar through the smooth jet nozzle into the reaction chamber pressed. The aqueous urea solution was at 26.5 bar at 20.70 kg / h (259 mol / h) metered into the reaction space. The temperature in the reaction space was 210 to 225 ° C. When relaxing behind the bezel, it came through that Evaporation of water to a temperature drop to around 200 ° C. At the same time excess ammonia and carbon dioxide formed during the reaction away. The hot mixture was placed in the storage tank, which was heated to 60 ° C. passed and 45% by weight sodium hydroxide solution was metered in, the pH was kept at about 9.5 by regulation. You get an orange-red aqueous PAS solution. The isolated solid, polyaspartic acid sodium salt, has  after GPC measurement an average molecular weight Mw of 2950. The product shows good sequestering and dispersing properties. The analysis results are summarized in Table 1.

Example 8

4.66 kg (64.8 mol) (25 mol% based on MA) acrylic acid are added an inhibitor (e.g. hydroquinone, 2,5-di-tert-butylphenol, methylphenol, N- Phenyl-β-naphthylamine, etc.) in 13.8 kg 40% aq. Ammonia solution as Ammonium salt dissolved. This mixture is used instead of the pure ammonia solution used in the reaction. Again, the was with a smooth jet nozzle Jet mixer provided tube reactor without a downstream high-viscosity reactor used. It was melted MSA at 100 ° C with a smooth jet 0.35 mm nozzle cross section with the 15 ° C cold acrylic acid-containing mixture solution mixed and dosed into the tubular reactor. After a reaction space length At 290 cm, an orifice with an inner diameter was now used for pressure maintenance of 2.1 mm in the pipeline. An indwelling tube with a length of 40 cm leads to a downstream 50 l stirred tank in which 20 kg Water are presented. The MSA melt was with a mass flow of 25.4 kg / h at 40 bar through the smooth jet nozzle into the reaction chamber. The aqueous mixture solution was at 18.5 bar at 18.6 kg / h in the reaction chamber dosed. The temperature in the reaction space was 220 to 235 ° C. In the Relaxation behind the aperture resulted in the evaporation of water Temperature drop to around 200 ° C. The hot mixture was applied to a Paddle snail given where one while evaporation of the remaining water Solidification of the product took place. An orange-red solid is obtained. By washing several times with water, it became unreacted starting materials exempted. After total hydrolysis, the isolated polymer contained aspartic acid units still found β-alanine units. The copoylymer has Measurement of an average molecular weight Mw of 2200.

Example 9

3.8 kg (25.8 mol) (10 mol% based on MA) glutamic acid are in 12.1 kg 40% aq. Ammonia solution dissolved as an ammonium salt. This mixture  is used in the reaction instead of the pure ammonia solution. In turn was the tube reactor provided with a smooth jet nozzle as jet mixer without downstream high-viscosity reactor used. It was melted with MSA 100 ° C via a smooth jet nozzle with a 0.35 mm nozzle cross section at 15 ° C cold glutamic acid-containing mixture solution and mixed in the tube reactor dosed. After a reaction chamber length of 290 cm, pressure was now maintained an orifice with an inner diameter of 2.1 mm in the pipeline used. An indwelling tube with a length of 40 cm leads to a downstream one 50 l stirred kettle in which 20 kg of water are placed. The MSA The melt was passed through the at a mass flow of 25.4 kg / h at 40 bar Smooth jet nozzle pressed into the reaction space. The aqueous mixture solution was metered into the reaction chamber at 18.6 bar at 15.9 kg / h. The temperature in Reaction space was 220 to 230 ° C. When relaxing behind the bezel came it by evaporating water to bring the temperature down to about 200 ° C. The hot mixture was placed on a paddle screw, where below Evaporation of the remaining water solidified the product. An orange-red solid is obtained. By washing it several times with water and 1N hydrochloric acid, he was freed from unreacted starting materials. In the isolated After total hydrolysis, polymer became glutamic acid units in addition to aspartic acid units found. According to GPC measurement, the copolymer has a medium Molecular weight Mw of 2600.

Design examples for the production of maleic acid Example 10

In this case too, a reactor system consisting of a Jet mixer and a tubular reactor used. It became melted MSA at 80 ° C via a smooth jet nozzle with a 0.4 mm nozzle cross section at 8 ° C cold 25% by weight aqueous ammonia solution mixed and in the downstream Dosed tubular reactor. After a reaction chamber length of 10 cm, pressure was maintained an orifice with an inside diameter of 0.75 mm in the pipeline screwed in. The reaction space was followed by an indwelling tube 1 m long before the product mixture was collected in a storage container. The MSA The melt was passed through the at a mass flow of 15.7 kg / h at 28 bar  Smooth jet nozzle pressed into the reaction space. The aqueous ammonia solution was metered into the reaction space at 20 bar at 11.4 kg / h. The temperature in Reaction space was 110 to 180 ° C. When relaxing behind the bezel came there is little to further evaporation of water and thus to a low Temperature reduction. The product was maleic acid in the form of white Crystals isolated. The melting point is 170 to 172 ° C, the purity 98%. The yield was 2.98 kg after a test period of ten minutes. H. 98.8% of theory Th., Maleic acid.

Example 11

Again this was done with a jet mixer and a subsequent one Pipe reactor reactor system used. It became melted MSA at 85 ° C via a smooth jet nozzle with a 0.7 mm nozzle cross section at 6 ° C cold 25% by weight aqueous ammonia solution mixed and in the downstream Dosed tubular reactor. After a reaction chamber length of 6 cm The diaphragm with an internal diameter of 0.75 mm is maintained under pressure Leave the pipeline. The indwelling tube downstream of the reaction space became shortened to 0.4 m. The MSA melt was with a mass flow of 45.8 kg / h at 36 bar through the smooth jet nozzle into the reaction chamber. The aqueous ammonia solution was at 30 bar at 34.3 kg / h in the reaction chamber dosed. The temperature in the reaction space was about 185 ° C. When relaxing behind the screen there was a vaporization of water Temperature drop to about 135 ° C. Maleinamic acid is obtained in 97% strength Yield and purity. The melting point is 169 to 172 ° C.

Claims (33)

1. A process for the continuous production of polymers with recurring succinyl units, in which maleic anhydride or a derivative thereof (starting material A) mixed with ammonia, an ammonia-providing compound or amides of carbonic acid (starting material B) and combined in a first exothermic reaction step N-containing low molecular weight derivative of maleic acid are reacted, and this derivative is polymerized in a subsequent second reaction step, characterized in that the reaction of the starting materials (A, B) takes place largely adiabatically in the first reaction step and the heat of reaction released is used to prevent the Bring reaction mixture to polymerization temperature and in the second reaction step to polymerize at least partially the N-containing low molecular weight derivative to obtain a polymer with recurring succinyl units. 2. The method according to claim 1, characterized in that as starting material A Maleic anhydride and derivatives of maleic anhydride, maleic acid or fumaric acid or mixtures thereof. 3. The method according to claim 1 to 2, characterized in that as educt B in addition to ammonia itself, ammonia-providing compounds ammonium hydrogen carbonate or diammonium carbonate or ammonium salts and Amides of carbonic acid, such as urea, isourea (ammonium cyanate), Carbamic acid, ammonium carbamide or mixtures of these are used will. 4. The method according to claim 1 to 3, characterized in that maleic anhydride or their derivatives and mixtures thereof as a melt or mixed with the nitrogenous educt B in solution. 5. The method according to claim 3 and 4, characterized in that the nitrogenous Educt B in pure form or in an organic solvent and / or dissolved in water is added to the starting material A.   6. The method according to claim 4 and 5, characterized in that as a solvent polar aprotic solvents such as dimethylformamide, N-alkylpyrrolidones, Sulfolan or supercritical gases such as CO₂ can be used. 7. The method according to claim 1 to 6, characterized in that the molar Ratio of nitrogen in educt B relative to maleic anhydride or a derivative thereof in the starting material A to a value between 0.1 and 5.0, preferably between 0.5 and 4.0 and very particularly preferably between 0.9 and 3.0. 8. The method according to claim 1 to 6, characterized in that the exothermic the first and second reaction step is used to organic solvents and / or the water or water of reaction formed to evaporate at least partially. 9. The method according to claim 1 to 8, characterized in that the starting materials (A, B) a fast mixing apparatus with a mixing time <2 s are supplied and then in the 1st reaction step the exothermic Reaction of the starting materials (A, B) takes place in less than 60 s. 10. The method according to claim 9, characterized in that the starting materials (A, B) are fed to a jet mixer, which is followed by a tubular reactor is. 11. The method according to claim 9, characterized in that the starting materials (A, B) are fed to a jet mixer, which is followed by an MPWR is. 12. The method according to claim 1 to 9, characterized in that the starting materials (A, B) in the first reaction step at temperatures of 0 ° C and 200 ° C are mixed and the exothermic reaction of the first reaction step provides enough heat so that the second reaction step at temperatures from 120 ° C to 500 ° C is carried out.   13. The method according to claim 10 to 12, characterized in that the Reaction temperature via the pressure in the reactor and the mass flows the feed materials A, B, and the content of organic solvent or water and / or a heating / cooling circuit is set. 14. The method according to claim 11, characterized in that the total residence time the starting materials (A, B) and the reaction mixture in the first and second reaction step at temperatures between 120 ° C and 200 ° C less than 30 min, at temperatures between 200 ° C and 250 ° C less than 10 min, at temperatures between 250 ° C and 300 ° C less than 5 min, and at temperatures above 300 ° C is less than 1 min. 15. The method according to claim 1 to 7, characterized in that the repeating succinyl units may have one of the following structures: 16. The method according to claim 1 to 14, characterized in that the starting materials A and B, preferably maleic anhydride and ammonia, are reacted with a molar excess of ammonia to give a polymer containing succinyl units with optionally recurring units of the following structure: 17. The method according to claim 16, characterized in that per mole of starting material A, preferably maleic anhydride, 1.8 to 25, preferably 2 to 10 mol, particularly preferably 2 to 5 mol of educt B, preferably ammonia, are used will. 18. The method according to claim 1 to 15, characterized in that in addition to the starting materials (A, B) further monomers, such as alcohols, dicarboxylic acids, Polycarboxylic acids, unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated polycarboxylic acids, aminocarboxylic acids, polyaminocarboxylic acids, Fatty acids, sugar or amines can be added continuously. 19. The method according to claim 16, characterized in that the co-monomers in the polymer in a proportion of 0.1 to 99.9 mol%, preferably from 0.1 to 40 mol% and particularly preferably from 0.1 to 25 mol% are included. 20. The method according to claim 1 to 19, characterized in that the resulting Polymer is hydrolyzed to the corresponding acid form. 21. The method according to claim 20, characterized in that the hydrolysis is carried out by adding a base.   22. The method according to claim 20, characterized in that the hydrolysis at temperatures between 20 ° C and the boiling point of polyaspartic acid containing suspension and carried out at a pH of 5 to 14 becomes. 23. A process for the continuous production of maleic acid, thereby characterized in that maleic anhydride or a derivative thereof with Ammonia or an ammonia-providing compound in one quick mixing apparatus with a mixing time <2 s and mixed in one subsequent reactor are implemented, the residence time and the temperature should be chosen so that none or almost none Polymerization takes place. 24. The method according to claim 23, characterized in that the starting materials mixed and at a temperature of 20 ° C to 250 ° C, preferably from 60 ° C to 200 ° C to be converted to maleic acid. 25. The method according to claim 23 to 24, characterized in that as a starting material melted maleic anhydride and as an educt an aqueous ammonia solution or ammonia dissolved in an organic solvent be used. 26. The method according to claim 22 to 25, characterized in that the Educts are fed to a jet mixer, which is followed by a reactor is. 27. The method according to claim 1 to 21, characterized in that one of the Educts (A, B) metered in at various metering points along the reactor becomes. 28. The method according to claim 1 to 21, characterized in that partially reacted reaction mixture is withdrawn from the reactor and in is recycled to the first reaction zone.   29. Use of the products produced according to claims 1 to 22 as a builder or cobuilders in detergents and cleaners. 30. Use of the products produced according to claims 1 to 22 as scale inhibitors in cooling circuits. 31. Use of the products prepared according to claims 1 to 22 for calcium sulfate inhibition in oil production. 32. Use of the products prepared according to claims 1 to 22 as dispersants for inorganic solids and dye pigments. 33. Use of the products produced according to claim 1 to 22 as a fertilizer additive.