WO1998004615A1 - Process for the preparation of polyaspartic acid - Google Patents
Process for the preparation of polyaspartic acid Download PDFInfo
- Publication number
- WO1998004615A1 WO1998004615A1 PCT/EP1997/003408 EP9703408W WO9804615A1 WO 1998004615 A1 WO1998004615 A1 WO 1998004615A1 EP 9703408 W EP9703408 W EP 9703408W WO 9804615 A1 WO9804615 A1 WO 9804615A1
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- WIPO (PCT)
- Prior art keywords
- acid
- mol
- process according
- reaction product
- reaction
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Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1092—Polysuccinimides
Definitions
- the invention relates lo a process for preparing polyaspartic acid
- Polyaspartic acid which herein refers to the free acid or to a salt thereof, can among a lot of applications suitably be applied as a builder for detergents, as a scale inhibitor, anticorrosive agent or additive foi fertilizers (EP-A 613 920)
- Object of the invention therefore is to develop an economic and technically feasible process which does not comprise the disadvantages mentioned above, delivering polyaspartic acid with very good quality
- the piocess for the preparation of polyaspartic acid is characterised in that a) maleic anhydride is converted with ammonia to a reaction product comprising 60 to 90 mol% aspartic acid,
- the reaction product is heated under atmospheric or sub-atmospheric pressure at a temperature from about 150 ° to 300 °C for a sufficient period of time to reach a dehydiation condensation to polysuccinimide and c) the polysuccinimide accordingly obtained is subsequently hydrolyzed in the presence of a base
- step a) is expediently performed by introducing maleic anhydride in water in such a manner that the reaction temperature during the addition does not exceed 90
- °C preferably 70 °C and a maleic acid concentration in water of 20 to 70% by weight, preferably 40 to 60% by weight is achieved
- an aqueous ammonia solution having a concentration of 15% by weight to 30% by weight of ammonia, preferably of 20% by weight to 25% by weight of ammonia is then added in such a manner that the reaction temperature does not exceed 50 °C
- OptionalK gaseous anhydrous ammonia can be introduced into the maleic acid solution until the intended concentration is reached
- the reaction mixture is treated in a sealed vessel, at a temperature of 140 °C to 200 C C , preferably 150 °C to 180 °C
- This reaction is conducted for a sufficient period of time, which as a rule is in the range of 0 5 to 6 h until the above mentioned reaction product composition (calculated on the dry product) is achieved
- the reaction mixture can then expediently be dried for instance by evaporation of the watei to get a product which preferably is in a granular form
- reaction product composition comprises
- step b) the reaction product is heated under atmospheric or sub-atmospheric pressure at a tempeiatuie from about 150 ° to 300 °C for a sufficient pe ⁇ od of time to reach a dehydration condensation to polysuccinimide
- the reaction preferably can be run at a temperature from about 180 °C to 250 °C for a sufficient period of time, as a rule from about 0 5 h to about 4 h, to reach a conversion to polysuccinimide of at least about 80%
- the reaction proceeds via a "solid state polymerization" and can be conducted in common equipments like a forced ventilation oven
- the reaction can be performed in presence of a catalyst, preferably in presence of phosphoric acid as catalyst
- Preferably concentrated phosphoric acid having a concentration of about 85% can be applied Usually similar reaction conditions as used for dehydration condensation without catalyst can be applied.
- the polysuccinimide accordingly prepared shows an average molecular weight Mw in the range from 1000 to l 'OOO, preferably in the range from 3000 to 8000
- the polysuccinimide obtained in step b) is converted to polyaspartic acid following methods well known in the art Accordingly the polysuccinimide is treated at an elevated temperature preferably from about 50 ° to 70 °C with an inorganic base expediently with an alkali- or an earth-alkali hydroxide Preferably an aqueous solution of sodium hydroxide is applied until the final pH is in the range of 9 to I I Usually no further recovery slcp is necessary
- the polyaspartic acid obtained shows an average molecular weight Mw in the range of
- the reactor was hermetically sealed and the temperature was raised at 150 °C in 1 h, 5) The temperature was kept at 150 +/- 2 °C for 6 h; then the reactor was cooled and the result inu solution was collected
- the reaction product is according to HPLC analysis and referred to 100 moles of starting MA composed of
- PSI 30 8 g PSI were obtained from 49 3 g of product (see point 4)
- Example 3 The same procedure as described in Example 1 was adopted, but the following differences were introduced
Abstract
Polyaspartic acid is prepared by converting maleic anhydride with ammonia in such a manner that a specific composition of Aspartic acid, Iminodisuccinic acid, Malic acid and Fumaric acid results, this composition is further reacted under dehydration condensation conditions to polysuccinimide and finally the polysuccinimide is hydrolysed to polyaspartic acid.
Description
Process for ( e preparation of Polyaspartic acid
The invention relates lo a process for preparing polyaspartic acid
Polyaspartic acid, which herein refers to the free acid or to a salt thereof, can among a lot of applications suitably be applied as a builder for detergents, as a scale inhibitor, anticorrosive agent or additive foi fertilizers (EP-A 613 920)
A great number of publications exist disclosing preparations and uses of polyaspartic acid Accordingly attempts have been made to directly convert Cj-dicarboxyhc acids or the anhydrides thereof like maleic anhydride or maleic acid with ammonia or ammonium salts to polysuccinimide which finallv is hydrolyzed to the polyaspartic acid (WO 95/20573 or WO 95/3 1494) The above mentioned raw materials are certainly the most convenient from the economic point of view However when thermally heated to form polysuccinimide a melt is formed at temperat ie of about 150 ° - 170 °C The melt iapidly transforms to a glassy, brittle solid This has the consequence that the reaction mass tends to stick and to become dark coloured while the reaction water is trapped thus giving a sponge-like reaction mass These problems had been overcome when aspartic acid either in its optical pure L- or D- form or in its racemic form (WO 95/00479. WO 93/04108 or EP 640641 ) were used as the condensation now could be performed in the solid state ("solid state polymerisation") Although giving polysuccinimide of good quality, the application of pure aspartic acid significantly increases process costs
Object of the invention therefore is to develop an economic and technically feasible process which does not comprise the disadvantages mentioned above, delivering polyaspartic acid with very good quality
The objects and advantages are achieved with the process of the invention
According to claim 1 the piocess for the preparation of polyaspartic acid is characterised in that a) maleic anhydride is converted with ammonia to a reaction product comprising 60 to 90 mol% aspartic acid,
2 to 20 moI% iminodisuccinic acid,
0 5 to 3 mol % malic acid and
0 5 to 1 5 moI% fumaric acid or the respective ammonium salts of the components b) the reaction product is heated under atmospheric or sub-atmospheric pressure at a temperature from about 150 ° to 300 °C for a sufficient period of time to reach a dehydiation condensation to polysuccinimide and
c) the polysuccinimide accordingly obtained is subsequently hydrolyzed in the presence of a base
The conversion within step a) is expediently performed by introducing maleic anhydride in water in such a manner that the reaction temperature during the addition does not exceed 90
°C, preferably 70 °C and a maleic acid concentration in water of 20 to 70% by weight, preferably 40 to 60% by weight is achieved
Suitably an aqueous ammonia solution having a concentration of 15% by weight to 30% by weight of ammonia, preferably of 20% by weight to 25% by weight of ammonia is then added in such a manner that the reaction temperature does not exceed 50 °C OptionalK gaseous anhydrous ammonia can be introduced into the maleic acid solution until the intended concentration is reached After this addition the reaction mixture is treated in a sealed vessel, at a temperature of 140 °C to 200 CC , preferably 150 °C to 180 °C This reaction is conducted for a sufficient period of time, which as a rule is in the range of 0 5 to 6 h until the above mentioned reaction product composition (calculated on the dry product) is achieved The reaction mixture can then expediently be dried for instance by evaporation of the watei to get a product which preferably is in a granular form
Preferably the reaction product composition comprises
70 to 88 ol% aspartic acid, 4 to 12 mol% iminodisuccinic acid,
1 to 2 mol °Ό malic acid and
5 to 12 mol% fumaric acid or the respective ammonium salts of the components
Within step b) the reaction product is heated under atmospheric or sub-atmospheric pressure at a tempeiatuie from about 150 ° to 300 °C for a sufficient peπod of time to reach a dehydration condensation to polysuccinimide
AH components, with the exception of iminodisuccinic acid, are hereby converted to polysuccinimide
As the unreacted iminodisuccinic acid itself is known as a potent additive for detergents or as antiscaling compositions (GB 1306331 ) it becomes evident that a major advantage of the process of the present invention is that instead of a pure aspartic acid a composition can be applied which is easily and economically accessible from maleic anhydride and ammonia
The reaction preferably can be run at a temperature from about 180 °C to 250 °C for a sufficient period of time, as a rule from about 0 5 h to about 4 h, to reach a conversion to polysuccinimide of at least about 80% Suitably the reaction proceeds via a "solid state polymerization" and can be conducted in common equipments like a forced ventilation oven
As an option the reaction can be performed in presence of a catalyst, preferably in presence of phosphoric acid as catalyst Preferably concentrated phosphoric acid having a concentration of about 85% can be applied Usually similar reaction conditions as used for dehydration condensation without catalyst can be applied. The polysuccinimide accordingly prepared shows an average molecular weight Mw in the range from 1000 to l 'OOO, preferably in the range from 3000 to 8000
Within the last step c) the polysuccinimide obtained in step b) is converted to polyaspartic acid following methods well known in the art Accordingly the polysuccinimide is treated at an elevated temperature preferably from about 50 ° to 70 °C with an inorganic base expediently with an alkali- or an earth-alkali hydroxide Preferably an aqueous solution of sodium hydroxide is applied until the final pH is in the range of 9 to I I Usually no further recovery slcp is necessary
The polyaspartic acid obtained shows an average molecular weight Mw in the range of
1 ' 100 to 12O00, preferably from 3'500 to 9'500 and is having a content of iminodisuccinic acid or of a salt thereof preferably the sodium salt thereof of from 2 parts to 22 parts per hundred parts of polyaspartic acid, preferably of from 3 parts to 13 parts per hundred parts of polyaspartic acid This illustrates that the process of the present inventions is best suited for the applications mentioned
Examples
Example I a) s nthesis of the raw material
1 ) 200 g of deionized water were poured into a stainless steel reactor,
2) 196 g (2 moles) of maleic anhydride (MA) were then added under stirring in small portions, taking care to avoid the temperature raises above 90 °C,
3) When the addition of MA was completed, the solution was cooled below 30 °C
272 g of a water solution of ammonia (25% weight = 4 moles of NH3) were added in such a manner that the temperature didn't exceed 50 °C,
4) The reactor was hermetically sealed and the temperature was raised at 150 °C in 1 h, 5) The temperature was kept at 150 +/- 2 °C for 6 h; then the reactor was cooled and the result inu solution was collected
The reaction product is according to HPLC analysis and referred to 100 moles of starting MA composed of
- Aspartic acid molar yield = 81 8%
- Imino-di-succinic acid molai yield = 9 6%
- Malic acid olai yield = 1 3%
- Fumaric acid molat yield = 1 0%
Consideiing the sloichiometry of the reaction, the components listed above as free acids were dissolved in the predominant form of mono-ammonium salts
b) Polysuccinimide (PSI) synthesis
500 g of solution of point a) were dried in a rotavapor at 70 °C, 5 bar 239 I g of a dried granular product were obtained, a part of that (51 2 g) was placed in a cap (8 cm diameter), reaching a layer of about 1 cm The cap was placed in a forced ventilation oven at 250 -f /- 3 °C for 4 h, thus obtaining g
30 O of PSI
c) preparation of polyaspartic acid, sodium salt
PSI was dissolved in NaOH 50% at 50 °C, and pH was adjusted to 10 5 The GPC analysis of the dissolved product showed a molecular weight (Mw) of 5700
Example 2
The same procedure as described in Example 1 was adopted, but the following differences weie introduced
I ) starling solution
- deionized water 280 0 g
- MA 147 g ( I 5 moles)
- Ni l. 25% 255 0 g (3 75 moles of NH,) 2) reaction conditions
- temperature 180 +/- 2 °C
- reaction time 4 h
3) l eactio product
- Aspartic acid molar yield = 86 9%
- lmino-di-succinic acid molar yield = 3 8%
- Malic acid molar yield = 1 0%
- Fumaric acid molar yield = 0 7%
4) dried reaction product 226 0 g of dried product were obtained from 560 g of solution ( see point 3)
5) PSI 30 8 g PSI were obtained from 49 3 g of product (see point 4)
6) Polyaspartic acid, sodium salt Mw = 7600
Example 3 The same procedure as described in Example 1 was adopted, but the following differences were introduced
I ) starting solution
- deionized water 280 0 g
- MA 196 g (2.0 moles)
- NH, 25% 204 g (3.0 moles of Nrf,)
2) reaction conditions - temperature . 140 +/- 2 °C
- reaction time 4 h
3) reaction product
- Aspartic acid molar yield = 63.5%
- Imino-di-succinic acid molar yield = 16.7%
- Malic acid molar yield = 2.2%
- Fumaric acid molar yield - 12 8%
4) dried reaction product 290 2 g of dried product were obtained from 540 g of solution (see point 3 )
5) PSI . 27 g PSI were obtained from 50 6 g of product (see point 4)
6) Polyaspartic acid, sodium salt: Mw = 3800
Claims
1 . Process for the preparation of polyaspartic acid or a salt thereof characterised in that a) maleic anhydride is converted with ammonia to a reaction product comprising
60 to 90 mol% aspartic acid, 2 to 20 mol% iminodisuccinic acid, 0 5 to 3 mol % malic acid and 0.5 to 15 mol% fumaric acid and/or the respective ammonium salts of the components b) the reaction product is heated under atmospheric or sub-atmospheric pressure at a tempeiatuie from about I 50 ° to 300 °C for a sufficient period of time to reach at least partly a dehydration condensation to polysuccinimide and c) the polysuccinimide accordingly obtained is subsequently hydrolyzed in the presence of a base
Process according to claim 1 characterized in that the preparation of the reaction product within step a ) is performed by introducing maleic anhydride in water in such a manner that the reaction temperature during the addition does not exceed 90 °C and a maleic acid concentration in water of 20 to 70% by weight is achieved, by subsequently adding an aeqoeus ammonia solution having a concentration of 15% to 30% in such a manner that the reaction temperature does not exceed 50 °C, by treating this reaction mixture under autogenous pressure and a temperature of 140 °C to 200 °C for a sufficient period of time and finally by removing the water to obtain said reaction product
3 Process according to claim I or 2 characterized in that a reaction product comprising 70 to 88 mol% aspartic acid,
4 to 12 mol% iminodisuccinic acid, I to 2 mol % malic acid and 2 to 12 mol% fumaric acid and/or the respectiv e ammonium salts of the components is obtained
Process according to claims 1 to 3 characterized in that the subsequent treatment of the reaction product within step b) is optionally accomplished in presence of a catalyst.
Process according to claim 4 characterized in that phosphoric acid is applied as catalyst 6 Process according to claims 1 to 4 characterized in that the dehydration condensation within step b) is performed in such a manner that the poysuccinimide obtained has an average moleculai weight Mw in the range of 1 '000 to l O'OOO
7 Process according to claims 1 to 6 characterized in that the hydrolysis within step c) is performed with an inorganic base
8 Process according to claims I to 7 characterized in that a polyaspartic acid is obtained having an average molecular weight Mw in the range of 1 ' 100 to 12O00
Process according to claims 1 to 8 characterized in that a polyaspartic acid is obtained having a content of iminodisuccinic acid or a salt thereof of 2 parts to 22 parts per hundred pai ls of polyaspartic acid
AMENDED CLAIMS
[received by the International Bureau on 24 December 1997 (24. 12.97) ; orig inal claims 1 -9 replaced by new claims 1 -8 (2 pages ) ]
1 Process for the preparation of polyaspartic acid or a salt thereof characterised in that a) maleic anhydride is converted with ammonia to a reaction product by introducing maleic anhydride in water in such a manner that the reaction temperature during the addition does not exceed 90 °C and a maleic acid concentration in water of 20 to 70% by weight is achieved, by subsequently adding an aqueous ammonia solution having a concentration of 15% to 30% in such a manner that the reaction temperature does not exceed 50 °C, by treating this reaction mixture under autogenous pressure and a temperature of 140 °C to 200 °C for a sufficient peπod of time and finally by removing the water to obtain said reaction product comprising 60 to 90 mol% aspartic acid, 2 to 20 mol% iminodisuccinic acid, 0 5 to 3 mol% malic acid, and
0 5 to 15 mol% fumaric acid and/or the respective ammonium salts of the components b) the reaction product is heated under atmospheric or sub-atmospheric pressure at a temperature from about 150° to 300 °C for a sufficient period of time to reach at least partly a dehydration condensation to polysuccinimide and c) the polysuccinimide accordingly obtained is subsequently hydrolyzed in the presence of a base
7, ζ Pi ocess according to claim I J *-ϊ}| characterized in that a reaction product comprising 70 to 88 mol% aspartic acid, 4 to 12 mol% iminodisuccinic acid,
1 to 2 mol % malic acid and 2 to 12 mol% fumaric acid and/oi the respective ammonium salts of the components is obtained
3 f Process according to claims 1 
in that the subsequent treatment of the teaction product within step b) is optionally accomplished in presence of a catalyst 3
-f jit Process accoiding to claιm 4" characterized in that phosphoric acid is applied as catalyst 3
5 # Process according to claims I to/ characterized in that the dehydration condensation within step b) is performed in such a manner that the poysuccinimide obtained has an average molecular weight Mw in the range of 1 '000 to l O'OOO
S ^ (t Process according to claims I to i characteπzed in that the hydrolysis within step c) is performed with an inorganic base
f £ Process according to claims 1 to X characterized in that a polyaspartic acid is obtained having an average molecular weight Mw in the range of 1 ' 100 to 12'000
8 Process according to claims I tθ/ ?K characterized in that a polyaspartic acid is obtained having a content of iminodisuccinic acid or a salt thereof of 2 parts to 22 parts per hundred parts of polyaspartic acid
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU34396/97A AU3439697A (en) | 1996-07-30 | 1997-06-30 | Process for the preparation of polyaspartic acid |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT96MI001635A IT1283642B1 (en) | 1996-07-30 | 1996-07-30 | PROCEDURE FOR THE PREPARATION OF POLYASPARTIC ACID |
| ITMI96A001635 | 1996-07-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1998004615A1 true WO1998004615A1 (en) | 1998-02-05 |
Family
ID=11374716
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1997/003408 WO1998004615A1 (en) | 1996-07-30 | 1997-06-30 | Process for the preparation of polyaspartic acid |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU3439697A (en) |
| IT (1) | IT1283642B1 (en) |
| WO (1) | WO1998004615A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109824893A (en) * | 2019-01-11 | 2019-05-31 | 吉林省产品质量监督检验院(吉林省农产品认证中心) | The preparation method of more gap polysuccinimides |
| WO2019157472A1 (en) * | 2018-02-11 | 2019-08-15 | Mcknight Gary David | Non-aqueous organo liquid delivery systems containing dispersed organo polycarboxylate functionalities that improves efficiencies and properties of nitrogen sources |
| CN116969611A (en) * | 2023-09-22 | 2023-10-31 | 杭州尚善若水环保科技有限公司 | Corrosion and scale inhibition mixture and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994006845A1 (en) * | 1992-09-18 | 1994-03-31 | Donlar Corporation | Production of polysuccinimide and polyaspartic acid from maleic anhydride and ammonia |
| WO1994015993A1 (en) * | 1993-01-02 | 1994-07-21 | Basf Aktiengesellschaft | Method of producing polymers of aspartic acid and the use of such polymers |
| EP0613920A1 (en) * | 1993-03-02 | 1994-09-07 | Bayer Ag | Process for preparing polyaspartic acid |
-
1996
- 1996-07-30 IT IT96MI001635A patent/IT1283642B1/en active IP Right Grant
-
1997
- 1997-06-30 WO PCT/EP1997/003408 patent/WO1998004615A1/en active Application Filing
- 1997-06-30 AU AU34396/97A patent/AU3439697A/en not_active Abandoned
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994006845A1 (en) * | 1992-09-18 | 1994-03-31 | Donlar Corporation | Production of polysuccinimide and polyaspartic acid from maleic anhydride and ammonia |
| WO1994015993A1 (en) * | 1993-01-02 | 1994-07-21 | Basf Aktiengesellschaft | Method of producing polymers of aspartic acid and the use of such polymers |
| EP0613920A1 (en) * | 1993-03-02 | 1994-09-07 | Bayer Ag | Process for preparing polyaspartic acid |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019157472A1 (en) * | 2018-02-11 | 2019-08-15 | Mcknight Gary David | Non-aqueous organo liquid delivery systems containing dispersed organo polycarboxylate functionalities that improves efficiencies and properties of nitrogen sources |
| CN109824893A (en) * | 2019-01-11 | 2019-05-31 | 吉林省产品质量监督检验院(吉林省农产品认证中心) | The preparation method of more gap polysuccinimides |
| CN116969611A (en) * | 2023-09-22 | 2023-10-31 | 杭州尚善若水环保科技有限公司 | Corrosion and scale inhibition mixture and application thereof |
| CN116969611B (en) * | 2023-09-22 | 2024-01-23 | 杭州尚善若水环保科技有限公司 | Corrosion and scale inhibition mixture and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| ITMI961635A1 (en) | 1998-01-30 |
| ITMI961635A0 (en) | 1996-07-30 |
| AU3439697A (en) | 1998-02-20 |
| IT1283642B1 (en) | 1998-04-23 |
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