Note: Descriptions are shown in the official language in which they were submitted.
Le A 31 389-Forei~n Countries/Zb/ngb/S-P ~ l 9 5 9 3 1
Process for the PreParation of polvmers havin~ recurrin~ succinvl units
The invention relates to a process for the prep~lion of polymers having recurring
5 succinyl units.
The polymers thus prepared can be hydrolyzed by organic and inorganic bases to
give the corresponding derivatives.
The plq)al~Lion of polymers cont~ining succinyl units, in particular polyaspartic
acids and polysuccinimide, has been the subject of intensive research for some
10 years.
US-A 4 839 461 (= EP-A 0 256 366) describes the preparation of polyaspartic
acid from maleic anhydride, water and ammonia. It is known from US-A
4 590 260 that amino acids can be subjected to polycondensation together with
derivatives of malic, maleic and/or fumaric acid at 100 to 225C. According to
US-A 4 696 981, microwaves can be employed for carrying out such a reaction.
US-A 5 288 783 describes the preparation of polyaspartic acid from maleic acid or
fumaric acid, water and ammonia at temperatures of 190 to 350C and at
temperatures of 160 to 200C by extrusion. The polysuccinimide prepared by one
of the two process routes is then hydrolyzed under alkaline conditions to give
20 polyaspartic acid.
EP-A 0 625 531 describes a continuous process for the preparation of polymers
from monoethylenically unsaturated acids or anhydrides and a nitrogen-cont~iningcomponent, it being possible for a fluidizing agent to be present.
The present invention relates to a process for the preparation of polymers having
25 recurring succinyl units by reaction of A, an unsaturated C4-dicarboxylic acid or a
derivative thereof, with B, a nitrogen-donating compound, in a first reaction step
to give a reaction mixture comprising at least one low molecular weight reactionproduct of A and B and/or a prepolymer of A and B, preferably having a
molecular weight Mw <1300, and subsequent continuous feeding of the reaction
30 mixture into a continuously operating reactor and treatment of the reaction mixture
at a temperature of 140 to 350C to give the polymer having recurring succinyl
units and a molecular weight Mw >1300 in a second reaction step.
Le A 31 389-Foreign Countries 2 ~ 9 5 9 3 1
Preferred compounds A are maleic anhydride, maleic acid and fumaric acid. They
can be employed individually or as a mixture.
Preferred compounds B are ammonia or compounds which liberate ammonia, in
particular ammonium salts and amides of carbonic acid, such as, for example,
5 ammonium bicarbonate, diammonium carbonate, urea, isourea (ammonium cya-
nate), carbamic acid or ammonium carbonate. Other organic and inorganic
ammonium salts can also likewise be employed. These precursors can be
employed individually or as mixtures in bulk or solution. If ammonia is employedas precursor B, this can also be used in gaseous form.
10 The reaction mixtures are preferably prepared either by reaction of maleic
anhydride with ammonia or ammonia derivatives or by reaction of maleic
anhydride first with water to give maleic acid, and subsequent reaction with
ammonia and ammonia derivatives.
In a preferred embodiment, maleic anhydride is reacted with ammonia or ammonia
15 derivatives. Suitable solvents can be used in this reaction. Water is preferably to
be employed.
Depending on the conditions under which the reaction is carried out, maleic
anhydride secondary derivatives are formed, such as, for example, maleamic acid,maleamic acid ammonium salt, maleic acid monoammonium salt, maleic acid
20 diammonium salt, aspartic acid, aspartic acid monoammonium salt, aspartic acid
diammonium salt, iminodisuccinate mono-, di-, tri- or tetraammonium salt, aspara-
gine, asparagine ammonium salt, iminodisuccinatediamide diammonium salt and
condensation products resulting therefrom. In the presence of water, the corres-ponding ammonium salts are also formed by hydrolysis of the acid amides.
25 In another preferred embodiment, maleic anhydride is first reacted with water to
give maleic acid, which then reacts with ammonia or ammonia derivatives in
aqueous solution to give a reaction mixture.
According to the invention, reaction mixtures which can additionally comprise the
corresponding fumaric acid derivatives and malic acid derivatives can also be
30 formed. Furthermore, all components containing amino groups can occur in
Le A 31 389-Foreign Countries 2 1 9 5 ~ 3 1
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condensed form with the other components cont~ining carboxylic acid to form
peptide bonds.
Maleic anhydride and derivatives thereof are preferably employed as precursor A
in amounts such that the molar ratio of nitrogen in precursor B in relation to the
5 maleic anhydride or a derivative thereof in precursor A is between 0.1 and 25,preferably between 0.5 and 8 and especially preferably between 0.9 and 4.
The first reaction step is a rapid, highly exothermic reaction, as a result of which
product damage may arise in the case of a non-specific reaction procedure, for
example by a severe increase in temperature. According to the invention, however,
10 a controlled temperature program can be ensured under preferably constant
reaction conditions in order to prepare a desired reaction mixture. Preferred
reaction conditions are temperatures between 60 and 250C, in particular 70 to
170C and particularly preferably 80 to 150C. The residence times can vary, in
particular, between 1 minute and some hours and are preferably 2 mimltes to
15 3 hours. The pressures are established specifically as a function of the reaction
procedure and/or the temperature. If applopliate, the pres~we can be establishedby addition of inert gas.
All reactors which allow good regulation of the reaction conditions are suitable in
particular for carrying out the first reaction step. It is advantageous to carry out
20 the reaction in discontinuously operating apparatuses which can provide an
adequate residence time. In this case, the reaction volume can be used to dilute the
precursor streams and therefore reduce the rate of reaction and nevertheless realize
a sufficient reaction temperature which allows the formation of the desired
intermediate products. Preferred reactors are all types of stirred tank reactors with
25 and without pumped circulation, stirred tank cascades, loop reactors, tube reactors
with recycling and the like. If gaseous ammonia is used, examples of reactors
which may be mentioned are: bubble columns, gassed stirred tanks and airlift loop
reactors.
The first reaction step is preferably carried out in a discontinuous stirred tank. In
30 this case, one of the precursors A or B can be initially introduced, if appropriate
in a solvent, and the other precursor can be added. In another embodiment, the
precursors A and B are fed simultaneously to a discontinuous reactor (semi-batchprocedure). If appropriate, the precursors are fed to the discontinuous reactor in
Le A 31 389-Foreign Countries 2 1 `~ 5 ~ 3 1
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~ premixed form. All types of mixers can be employed here. For example, these can
be jet mixers, such as, for example, nozzle mixers, static mixers or dynamic
mixers.
If gaseous ammonia is used, this is preferably fed to the reactor via suitable gas
5 distributors. All types of static gassing units (for example perforated plate,sint~.ring plate, annular gassing unit, gassing lance and the like) and dynamic
gassing units (for example injectors, ejectors, gassing stirrers and the like) are
conceivable. The gaseous ammonia feed can also be effected in a pumped
circulation using suitable in-line mixers (nozzles, static mixers, injectors, ejectors).
10 When metering into the reactor has been concluded, the reaction mixture can
either be polymerized directly or, preferably, heated up to the desired reactiontemperature and kept at the reaction temperature for a certain time. The reactor is
as a rule kept under pres~ure here. This prevents the solvent and/or any water of
reaction formed from evaporating out of the reaction mixture. In another
15 embodiment, the solvent and/or any water of reaction formed are evaporated off in
a specific manner by controlling the pressure, in order to control the temperature
and/or the properties of the reaction mixture in a specif1c manner.
The complex reaction mixtures obtained in the first discontinuous reaction step
have not yet been described for preparation of polymers having recurring succinyl
20 units. They differ from the known starting products for the preparation of
polyaspartic acid by their complex composition. Above all, the amino group of
aspartic acid necessary for building up polypeptides is blocked in the imino-
disuccinates by addition of a further C4 unit. It was therefore not obvious thatsuch compounds or mixtures comprising these compounds are suitable for building
25 up polymers.
The reaction mixture produced in the first reaction step, which also includes
mixtures of various previously prepared reaction mixtures and, where appropriate,
mixtures of a reaction mixture or various reaction mixtures with the precursors A
and/or B, is subjected to thermal polymerization in a suitable apparatus in the
30 second reaction step to give the desired product. The choice of reaction mixtures
here depends on the desired product quality for the various fields of use of theproducts. In a preferred embodiment, several discontinuous reactors for the first
reaction step are operated in parallel with the reactor for the continuing thermal
Le A 31 389-Forei~n Countries 2 i 9 5 9 3 1
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polymerization in one plant. A high degree of flexibility of the production plant is
achieved in this way.
All appal~uses which provide the necessary minimum residence time for the
polymerization, coupled with a narrow residence time distribution of the viscous-
liquid phase, and allow the necessary temperature program and at the same time at
least partial evaporation of the solvent, in particular the water, and of the water
formed during the reaction are preferably suitable for the thermal polymerization.
Furthermore, for building up polymer chains of uniform chain length, the thermalpolymerization should be carried out as far as possible in a residence time which
is the same for all molecules under reaction conditions which are as identical as
possible. Suitable reactors having a narrow residence time spectrum are known inthe relevant literature (for example Ullmann: Encyclopedia of Industrial
Chemistry, 1992, Volume B4, 97-120).
Preferred devices for the therrnal polymerization are thus all appa~ ses which
have a defined residence time with a narrow residence time distribution for the
solid or highly viscous liquid phase and at the same time allow good temperaturecontrol by at least partial evaporation of the solvent and/or of the water of reaction
formed during the polymerization. Such preferred devices can be, for example,
a) Delay tubes, cf.
O. Levenspiel
The Chemical Reactor Omnibook
OSU Book Stores Inc. Corrallis Oregon
January 1989, Chapters 3-5
b) High viscosity reactors with movable baffles, preferably a screw or List
reactor, such as are described in EP-A 0 612 784 Al.
c) Driers (for example paddle driers or spray driers), preferably such as are
described in DE-A-4 425 952.
d) Stirred tank cascades, in particular such as are described by Levenspiel (see above).
Le A 31 389-Foreign Countries 2 1 ~ 5 ~ 3 1
e) Thin film evaporators, in particular such as are described by W.L. McCade,
J.C. Smith, Unit operations of chemical engineering, McGrace Hill, 2nd
edition, 1967, Chapter 16, page 445.
f) High viscosity reactors without movable baffles (for example multi-phase
helical tube reactors (MP~)), in particular such as are described in DT
1 667 051 and DE 219 967
g) Microwave reactors, in particular such as are described in US-A 4 696 981.
Of course, combinations of the above-mentioned devices may be used. Particularlygood results are achieved if a tube reactor or an MPHR has been used. These
10 apparatuses have proved particularly suitable for carrying out the process
according to the invention.
To control the reactor temperature of the reactions carried out, complete or also
partial circulation of the reaction mixture in combination with removal and supply
of heat can be effected. All the reactors of the abovementioned construction with
15 recycling of the reaction mixture in combination with removal and supply of heat
and all loop reactors are particularly suitable for such a reaction procedure.
In a preferred embodiment, for the desired reaction procedure a reaction mixtureproduced in the first reaction step or mixtures of various previously prepared
reaction mixtures and, where appropriate, mixtures of a reaction mixture or various
20 prepolymers with the precursors A and/or B or one precursor component A and/or
B or a solvent can be metered in at several points in a suitable manner along the
tube or multiphase helical tube reactor, so that an optimum temperature profile and
optimum product properties can be achieved. The number of metering points is
preferably in the range of up to 10. The type of feeding is chosen such that good
25 mixing with the reaction solution takes place.
The prepolymer produced in the first reaction step or mixtures of various
previously prepared prepolymers or, where appropriate, mixtures of a prepolymer
or various prepolymers with the precursors A and/or B are fed into the
polymerization reactor at temperatures between 50C and 270C, depending on the
30 substances used. The removal or supply of heat to the reactor is controlled such
that the second reaction step can then take place at 120 to 350C, preferably at
Le A 31 389-Forei~n Countries ~ 1 9 5 9 3 1
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140 to 300C and particularly preferably at 140 to 270C, depending on the nature
and concentration of the substances used. The temperature is advantageously
established via the pressure in the reactor and the mass flows of the prepolymerproduced in the first reaction step and fed in or mixtures of various previously5 prepared prepolymers or, where applopliate, mixtures of a prepolymer or various
prepolymers with the precursors A and/or B, and the content of solvent. Product-precursor ranges with different telllpel~ules can furthermore be brought into
contact directly or indirectly in the reaction system for the purpose of heat
exchange.
10 The residence times in the reactor system to be used for the second reaction step
are up to 120 minutes. Residence times of up to 30 mimltes are preferred.
Residence times which decrease with increasing temperature are particularly
preferred, i.e. less than 30 minutes at temperatures between 120 and 200C; lessthan 10 minutes at temperatures between 200 and 250C; less than 5 minutes at
temperatures between 250 and 300C; and less than 2 minutes at temperatures
above 300C. The residence time is preferably chosen such that virtually complete
polymerization takes place. The resulting reaction products are hot solutions orsolvent-cont~ining or aqueous melts, depending on the water or solvent content,
because of the enthalpy of reaction liberated and the removal or supply of heat.
20 The polymers prepared by the process according to the invention contain recurring
succinyl units having at least one of the following structures:
o O -- o --
~NH-- ~NH ~U,
NH2 ~ONH4
_ O _ _ O _ O
2 3
-- O o
--NH ~ NH--
N
O H O
Le A 31 389-Foreign Countries 2 1 9 5 9 3 1
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-- o o
- N /~ N
\~N~
O H O
-- O O
N /L~ ~ NH -
\~N~
O H O
R = ONH4, NH2 or the structures 1, 2, 3, 4, 5 and 6
In general, the polymers chiefly contain recllrring units 1, 2 and 3.
In addition, by a suitable reaction procedure and choice of precursors, the
polymers can contain other recurring units, for example
a) malic acid units of the formula
-- O
~O
~,ONH4 and
b) maleic acid and fumaric acid units of the formula
o o
~¦ and ~\
~f
O _ O
Le A 31 389-Forei~n Countries 2 1 9 5 9 3 1
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The chemical structure is preferably analyzed by l3C-N~, FT-IR and, after total
hydrolysis, by HPLC, GC and GC/MS.
According to a further development of the invention, the structure of the resulting
polysuccinimide can be influenced by the stoichiometric ratio of the precursors.
The polymerization products can be solvolyzed. Suitable reaction partners are
alkali metal and alkaline earth metal hydroxides or carbonates, such as, for
example, sodium hydroxide solution, potassium hydroxide solution, sodium
carbonate or potassium carbonate, ammonia and amines, such as triethyl~mine,
triethanolamine, diethylamine, diethanolamine, alkylamines and the like. Hydro-
lysis at a pH of 7 to 12 is preferred here.
The resulting products contain recurrin~ aspartic acid units which, in the form of
the free acid, correspond to the following formulae:
--CH--CO -NH - CH2 CO--NH--
and ¦
CH2 COOH --CH--COO H
a form 13 form
If the polymer is built up entirely or essentially from these recurring units, it is a
polyaspartic acid.
In general, the content of the ~ form is more than 50 %, preferably more than
7o o/o
The temperature during the hydrolysis is suitably in a range including up to theboiling point of the polymer suspension, and preferably 20 to 150C. If
applop.iate, the hydrolysis is carried out under pressure. A salt is as a rule
obtained here.
However, it is also possible to obtain free acids by purely aqueous hydrolysis or
treatment of the salt with acids or acid ion exchangers.
Different chain lengths or molecular weights can be established, depending on the
reaction conditions, for example residence time and temperature of the
Le A 31 389-Forei~n Countries 2 ~ 9 5 9 3 1
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polymerization. According to analyses by gel permeation chromatography,
molecular weights of Mw = 1300 to 10,000, preferably 1300 to 5000, particularly
preferably 1300 to 4500, are obtained in particular.
The polymers prepared according to the invention can be used in non-hydrolyzed
or, preferably, in hydrolyzed form as an additive in low-phosphate and phosphate-
free detergents and cleaning compositions. They are builders for detergents and
have the effect of reducing encrustation and graying on the washed textile goodsduring the washing operation.
The polymers prepared according to the invention are furthermore suitable as
water treatment agents. They can be added to the water in cooling circulations,
evaporators or seawater des~lin~tion plants. They can furthermore be employed asagents for prevel~ling deposits during concentration of sugar cane juice.
They are furthermore suitable as a dispersing agent, bleaching agent stabilizer and
corrosion inhibitor, for dispersing organic and inorganic pigments, as an additive
in fertilizers and as a grinding auxiliary.
Because of their good dispersing properties, the polymers according to the
invention are also suitable as dispersing agents for inorganic pigments and for the
preparation of highly concentrated solids dispersions (slurries) of, for example,
alkaline earth metal hydroxides, such as, for example, Ca(OH)2 and Mg(OH)2, or
also their oxides and carbonates, and as an additive for cement or as a cement
liquefier.
The invention furthermore relates to a process for the preparation of modified
polymers in which
a) 0.1 to 99.9 mol% of precursors A and B and
b) 99.9 to 0.1 mol%
of fatty acids, fatty acid amides, polybasic carboxylic acids, anhydrides and
amides thereof, polybasic hydroxycarboxylic acids, anhydrides and amides thereof,
polyhydroxycarboxylic acids, aminocarboxylic acids, sugar-carboxylic acids,
alcohols, polyols, amines, polyamines, alkoxylated alcohols and amines, amino-
30 alcohols, amino-sugars, carbohydrates, ethylenically unsaturated mono- and poly-
Le A 31 389-Forei~n Counh-ies 2 1 9 5 9 3 1
11
carboxylic acids and anhydrides and amides thereof, protein hydrolysates, for
example maize protein hydrolysate and soya protein hydrolysate, aminosulfonic
acids and aminophosphonic acids are reacted by the process according to the
mvenhon.
5 The precursors A and B described under a) are employed in the polymerizahon
according to the invention to the extent of 0.1 to 99.9 mol%, preferably to the
extent of 60 to 99.9 mol% and particularly preferably to the extent of 75 to
99.9 mol%.
Possible components (b) of the polymers are all the fatty acids. They can be
10 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 and all the
naturally occllrring fatty acid mixtures, for example Cl2/Cl4- or Cl6/Cl8-fatty acid
mixtures. Acrylic acid and methacrylic acid can also be employed as unsaturated
15 fatty acids.
These acids can furthermore also be used in the form of their amides. Polybasic
carboxylic acids which can be employed are, for example, oxalic acid, succinic
acid, glutaric acid, adipic acid, malonic acid, suberic acid, aconitic acid, itaconic
acid, sulfosuccinic acid, alkenylsuccinic acid (C1-C26), 1,2,3-propanetricarboxylic
20 acid, butanetetracarboxylic acid, furandicarboxylic acid and pyridinedicarboxylic
acid. The anhydrides of polybasic carboxylic acids, for example succinic
anhydride, itaconic anhydride, aconitic anhydride and phthalic anhydride, can
likewise be used. Possible components (b) are furthermore also polybasic
hydroxycarboxylic acids and polyhydroxycarboxylic acids. In addition to at least25 one hydroxyl group, polybasic hydroxycarboxylic acids carry at least two or more
carboxyl groups. Examples which are mentioned here are malic acid, tartaric acid,
uvic acid, citric acid and isocitric acid.
In addition to one carboxylic acid group, monobasic polyhydroxycarboxylic acids
carry two or more hydroxyl groups, for example glyceric acid, dimethylolpropionic
30 acid, dimethylolbutyric acid and gluconic acid. Monohydric alcohols having, for
example, 1 to 22 C atoms, such as, for example, methanol, ethanol, n-propanol, i-
propanol, butanol, pentanol, hexanol, octanol, lauryl alcohol, stearyl alcohol and
the like are furthermore suitable. The alcohols can also optionally contain a double
Le A 31 389-Foreign Countries 2 1 9 5 9 3 1
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bond, such as allyl alcohol or oleyl alcohol. These alcohols can furthermore be
alkoxylated, for example with ethylene oxide or propylene oxide. The adducts of 3
to 50 mol of ethylene oxide on fatty alcohols or oxo alcohols are, in particular, of
industrial interest. Polyols which are either saturated or unsaturated can
5 furthermore be employed as component (b), such as, for example, ethylene glycol,
propylene glycol, butanediol, butenediol, glycerol, trimethylolpropane, penta-
erythritol, sorbitol and neopentylglycol, as well as alkoxylated polyols, such as
polyethylene glycols, polypropylene glycols, ethoxylated trimethylolpropane,
glycerol or pentaelyl~litol having molecular weights of up to 6000. Comonomers
10 (b) which are furthermore suitable are also amines, such as Cl-C22-alkylamines,
for example methylamine, ethylamine, propylamine, butylamine, cyclohexylamine,
octylamine, isooctylamine (ethylhexylamine), stearylamine, allylamine, oleylamine,
ethylenediamine, diethylenetriamine, hexamethylenediamine, piperazine, diamino-
butane, dimethylamine, diethylamine, hydroxylamine, hydrazine, ethanolamine,
15 diethanolamine and aminopropanediol, and polyalkyleneamines, such as poly-
ethyleneamine having molecular weights of up to 6000. The amines can also be
alkoxylated, for example the addition products of 3 to 30 mol of ethylene oxide on
fatty amines, such as oleylamine, palmitylamine or stearylamine. Amino-sugars,
such as aminosorbitol or chitosamine, are furthermore also suitable. Carbohydrates,
20 such as glucose, sucrose, maltose, dextrins, starch, or sugar-carboxylic acids, for
example mucic acid, gluconic acid, glucuronic acid or glucaric acid, are also
suitable as component (b). Amino acids, proteinogens, such as glycine, alanine,
glutamic acid and Iysine, or non-proteinogens, such as 4-aminobutyric acid,
diaminosuccinic acid, 11-aminoundecanoic acid and 6-aminocaproic acid, can
25 furthermore be employed as component (b). The compounds of component (b) are
employed for the polymerization in amounts of 0.1 to 99.9 mol%, preferably 0.1
to 40 mol%, particularly preferably 0.1 to 25 mol%. It is possible to employ a
single compound of component (b) or mixtures of two or more compounds of (b).
The compounds of component (b) can be mixed with one of the main precursors
30 (a) in the desired ratio and employed as a mixture in the f1rst reaction stage.
In another embodiment, the compounds of component (b) are added to the reaction
mixture when carrying out the second reaction step on entry into the reactor forthe thermal polymerization. It is likewise possible to meter in the compounds ofcomponent (b) simultaneously with the main precursors (a) in the first reaction
3 5 step.
Le A 31 389-Forei~n Countries 2 9 5 9 3 1
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If monofunctional compounds such as alcohols, amines, fatty acids or fatty acid
amides are used as component (b), they are incorporated at the chain end. They
act as chain t~rmin~tors and lower the molecular weight. Polyfunctional com-
pounds of component (b) can be incorporated in the finished polymer both at the
5 chain end and in random distribution over the polymer chain.
The crude polymers can be freed from monomeric contents by customary methods
of working up, for example by extraction with water and 1 N hydrochloric acid orby membrane filkation. The copolymers are analyzed by 13C- and l5N-NMR
spectroscopy, FT-IR speckoscopy and, after total hydrolysis, by HPLC, GC and
1 0 GC-MS.
The modified polymers are preferably prepared from the polysuccinimides by
aqueous hydrolysis at 20C to 150C and pH 7 to 12, if appropliate under
pressure. However, this reaction can also be carried out at temperatures outside the
stated temperature range and at other pH values. Suitable bases are alkali metal15 and alkaline earth metal hydroxides or carbonates, such as, for example, sodium
hydroxide solution, potassium hydroxide solution, sodium carbonate or potassium
carbonate, ammonia and amines, such as triethylamine, triethanolamine, diethyl-
amine, diethanolamine, alkylamines and the like. Partially or completely neu-
kalized copolymers which comprise 0.1 to 99.9 mol% of aspartic acid and 99.9 to
20 0.1 mol% of at least one compound (b) in copolymerized form are obtained
If primary amines or bases which carry primary amino groups are used for the
hydrolysis, the amine salts formed can be converted into the corresponding amides
by dehydration. The water can be split off by heat treatment at temperatures of
30C to 250C, if appropriate assisted by vacuum.
25 The modified polymers according to the invention can be used as an additive in
low-phosphate and phosphate-free detergents and cleaning compositions. The
polymers are builders for detergents and have the effect of reducing encrustation
and graying on washed textile goods during the washing operation.
The modified polymers according to the invention are furthermore suitable as
30 water treatment agents. They can be added to the water in cooling circulations,
evaporators or seawater des~lin~tion plants. They can furthermore be employed asagents which prevent deposits during concentration of sugar cane juice.
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Because of their good dispersing properties, the modified polymers according to
the invention are also suitable as dispersing agents for inorganic pigments and for
the preparation of highly concentrated solids dispersions (slurries) of, for example,
alkaline earth metal hydroxides, such as, for example, Ca(OH)2 and Mg(OH)2, or
5 also their oxides and carbonates, and as an additive for cement or as a cement liquefier.
The invention is explained in more detail in the following with the aid of
embodiment examples.
Exam~les
10 Polymers having recurring succinyl units were obtained as follows:
Exam~le 1
1.1 Preparation of a 74.5 % stren~th by wei~ht maleic acid (NHl!l7 salt
solution
51.7 kg of water are initially introduced into a stirred tank and heated to
60C. 75.0 kg _ 0.765 kmol of maleic anhydride are added in portions. The
temperature is increased to 80C. Thereafter, 22.1 kg _ 1.3 kmol of
ammonia gas are added. During this operation, the temperature is raised to
100C until the end of the metering of the ammonia. 148.8 kg of a 74.5 %
strength by weight MS(NH4)l 7 salt solution are obtained.
20 1.2 Heat treatment of the solution
The resulting solution is heat-treated at 100C for 16 hours.
1.3 Polymerization of the heat-treated solution
The heat-treated solution is pumped at about 21 kg/hour into a heated
helical tube of 58 m length and 15 mm cross-section. The polymerization
is carried out there at about 190-200C. During this operation, most of the
water of solution and reaction can evaporate.
Le A 31 389-Foreign Countries ~ 1 9 5 9 3 ~
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At the end of the tube, the polymeric crude product is discharged by the
flow which forms individually in the helical tube, without forced
conveying. The hot crude product is diluted with water in a tank connected
to the tube. Analysis shows the following composition, based on carbon
(C4 units): total nitrogen (N) 177 % of theory.
1.4 Hydrolysis to ~ive polyaspartic acid Na salt
The amount of sodium hydroxide solution necessary for complete
hydrolysis of the carboxyl groups is det~rmined by the hydrolysis number
(HN). Peptide bonds are not hydrolyzed by the determination method. The
HN for the resulting crude product is 3.08 mmol of NaOH/g of crude
product solution.
The hydrolysis is carried out with sodium hydroxide solution at 130C
under pressure for 3 hours. The ammonia liberated is then distilled off.
1.5 Analysis of the PAA Na salt solution
The resulting PAA Na salt solution has a content of 30 % of carbon.
Determin~tion of the molecular weight by gel permeation chromatography
(GPC) gives a weight-average Mw f 1390. Determination of the calcium
carbonate dispersing capacity (CCC) at 25C, pH 11, gives a CCC value of
22 mg of CaC03/g of PAA Na salt. The ZnO content of an aqueous
dispersion of 10 g of ZnO topped up to 200 ml with water shows a value
of 67 % of theory after 2 hours at a PAA Na salt amount of 20 mg, 74 %
of theory at 50 mg and 64 % of theory when the amount used is 100 mg.
The data show that by polymerization of a heat-treated MA NH4 salt
solution which has a heterogeneous composition, a polyaspartic acid Na
salt which has dispersing and sequestering properties can be obtained.
Example 2
The heat-treated solution from Example 1 is again employed for the
polymerization in an amount of 21 kg/hour. The reaction temperature in the 58 m
helical tube reactor is 200 to 210C. Analysis of the crude product introduced into
30 water shows the following composition: total nitrogen (N) 177 % of theory. With
Le A 31 389-Forei~n Countries 2 1 9 5 9 3 1
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an HN of 3.46 mmol of NaOH/g of PAA crude product solution, the hydrolysis is
carried out accordingly. The 24 % strength by weight PAA Na salt solution shows
the following analysis values and properties:
Mw (from GPC) = 1690; CCC = 35 mg of CaC03/g of PAA Na salt; ZnO content
of an aqueous dispersion at 20C, pH 9.5 = 71 % of theory if 20 mg of PAA Na
salt are used, = 76 % of theory at 50 mg of PAA Na salt, = 78 % of theory at
100 mg of PAA Na salt and = 73 % of theory at 200 mg of PAA Na salt.
Example 3
3.1 Preparation of a 73.6 % strength maleic acid (NH,I)I 3 salt solution
The procedure is as in Example 1.1. 51.7 kg of water, 75 kg of MAA and
16.9 kg of ammonia gas were employed this time. 143.6 kg of solution
were obtained.
3.2 Heat treatment of the solution
The solution is heat-treated at 100C for 5 hours.
15 3.3 Polymerization of the heat-treated solution
The heat-treated solution is pumped at 20 kg/hour continuously into a
heated 58 m helical tube. The polymerization is carried out chiefly
(because of the temperature pattern which establishes itself) at temperatures
of 185-200C. The crude product introduced into water shows the
following N content: total N = 139 % of theory.
3.4 Hydrolysis of polyaspartic acid Na salt
The HN for the PAA crude product was 3.22 mmol of NaOH/g. After
hydrolysis at 130C for 3 hours, the ammonia liberated is distilled off. The
virtually odorless solution is analyzed.
25 3.5 Analysis of the PAA Na salt solution
The PAA Na salt solution shows a content of 33 % by weight of carbon.
Total N = 83 % of theory. M~, from GPC = 1790, the ZnO content of an
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aqueous dispersion is 69 % of theory, 76 % of theory, 78 % of theory and
77 % of theory when 20, 50, 100 and 200 mg of PAA Na salt are used.
ExamPIe 4
4.1 Plepal~ion of an 80.4 % stren~th maleic acid (NH1!l 3 salt solution
The procedure is as has been described in Example 1.1. 39.5 kg of water,
75 kg of MAA and 16.9 kg of ammonia gas are employed. 131.4 kg of
solution are obtained. The temperature level is raised by 10-15C because
of the concentrated mode of operation. The ammonium salt is therefore
kept in solution at 110-115C.
4.2 Heat treatment of the solution
The solution is heat treated at 110C for 1.5 hours.
4.3 Polymerization of the heat-treated solution
At a mass flow of 20 kg/hour, the solution is first heated to 215C in a
preheater 8 m long. The polymerization is then carried out at temperatures
of 145-215C in a helical tube 11.5 m long. The crude product introduced
into water shows the following N content: total N = 131 % of theory.
4.4 Hydrolysis to ~ive the PAA Na salt
The HN for the PAA crude product solution is 1.96 mmol/g. The
hydrolysis is carried out as in the previous examples at 130C for 3 hours
with subsequent removal of aqueous ammonia by distillation.
4.5 Analysis of the PAA Na salt solution
The PAA Na salt solution shows a content of 38 % by weight of carbon.
Total N = 75 % of theory. The CCC value is 28 mg of CaC03/g of P~A
Na salt; the ZnO content of an aqueous dispersion is 67 % of theory, 73 %
of theory and 69 % of theory when 20, 50 and 100 mg of PAA Na salt are
used.
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ExamPle 5
A 73.6 % strength by weight MA (NH4)l 3 salt solution is employed for heat
treatment at 100C, as has also already been described in Example 3.1. After heat
treatment for 3 hours, this solution is employed for the polymerization at a mass
5 flow of 30 kg/hour. During this operation, the solution is heated to 235C in a
preheater 8 m long and then polymerized at temperatures of 185-215C in a
helical tube 21 m long, water being evaporated off. The crude product is
introduced into water and shows the following N content: total N = 135 % of
theory. At a hydrolysis number of 1.96 mmol of NaOH/g, the hydrolysis is carried10 out, as described. The resulting 29 % strength PAA Na salt solution shows thefollowing analysis and properties: total N = 80 % of theory, Mw (from GPC) =
1720; CCC = 23 mg of CaCO3/g, the ZnO content when 10, 20, 50, 100 and
200 mg of PAA Na salt are used per 10 g of ZnO in an aqueous dispersion
(200 ml volume) is 66 % of theory, 82 % of theory, 83 % of theory, 84 % of
15 theory and 76 % of theory.
Exam~le 6
6.1 Preparation of a 73.6 % strength maleic acid (NH1)l 3 salt solution
The preparation is carried out as described in Example 3.1.
6.2 Heat treatment of the solution
The solution is heat treated at 100C for 6 hours. Analysis gives total N =
130 % of theory.
6.3 Polymerization of the heat-treated solution
At a mass flow of 40 kg/hour, the solution is first heated to 230C in a
preheater 8 m long. The polymerization is then carried out at temperatures
of 170-205C in a 21 m helical tube, water being evaporated off from the
reaction mixture. Due to some of the water of solution and reaction being
evaporated off, the viscosity of the liquid mass increases. However, the
flow properties of the reaction mixture are retained The hot reaction
mixture is additionally passed into an extruder heated to 100C. This is an
extruder with self-cleaning twin shafts rotating in the same direction having
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a cross-section of 59 mm per shaft and a length of 1050 mm (such
extruders have already been described in DBP 862 668 of 1944). The
power consumption was 6.8 kW at a speed of revolution of 130 rpm. A
beige-brown powdery to flaky product was discharged from the extruder. It
S had the following N content: total N = 111 % of theory.
6.4 Hydrolysis to ~ive the PAA Na salt
The HN of the polysuccinimide is 10.3 mmol of NaOH/g. The hydrolysis
is carried out as in the previous examples at 130C for 3 hours in an
autoclave, aqueous ammonia subsequently being distilled off.
10 6.5 Analysis of the PAA Na salt solution
The PAA Na salt solution shows a content of 31 % by weight of carbon
(C4 units). Total N = 89 % of theory, CCC = 15 mg of CaCO3/g of PAA
Na salt; the ZnO content of an aqueous dispersion is 64, 74, 76, 77 and
71 % of theory if 20, 50, 100, 200 and 300 mg of PAA Na salt are used;
M~, (from GPC) = 2040.
It is thus demonstrated that a significant build-up of molecular weights was
obtained in this example by the use of an extruder. The polymer shows a
broad use profile in its dispersing properties. The dispersing action also
exists for numerous other pigments (for example titanium oxides and iron
oxides), mineral salts (for example calcium carbonate, magnesium
carbonate and calcium and magnesium hydroxides and oxides) and ceramic
powders.
The determination of the ZnO content of an aqueous dispersion was carried out inaccordance with the following instructions:
1 g of the substance to be investigated is dissolved in 100 ml of distilled water.
The pH of the sample should be 10 and is to be corrected if necessary by addition
of 1 N hydrochloric acid or 1 N sodium hydroxide solution. The sample thus
prepared is transferred into a 100 ml volumetric flask and made up to exactly
100 ml of stock solution with distilled water.
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10.0 g of ZnO analytical grade (Merck) are initially introduced into a 250 ml
mixing cylinder and suspended in 140 to 170 ml of water. The following amounts
of stock solution are needed for testing of the activity of the concentrations
mentioned:
mg in 1 ml of stock solution
mg in 2 ml of stock solution
mg in 5 ml of stock solution
100 mg in 10 ml of stock solution
200 mg in 20 ml of stock solution
300 mg in 30 ml of stock solution
The mixture is stirred with an Ultraturrax stirrer at 24,000 min~l for 30 seconds,
the stirrer is rinsed off with distilled water and the suspension is made up to
200 ml. The sample suspension finished in this way is shaken three times
m~nll~lly and left to stand at room temperature for 3 hours.
15 An aliquot is then removed with a 5 ml volumetric pipette at the 150 ml mark and
transferred to a 50 ml measuring cylinder into which 10 ml of 1 N hydrochloric
acid and about 20 ml of water have been initially introduced. After the measuring
cylinder has been topped up, an aliquot of 10 ml is removed from this and titrated
with 0.1 N EDTA solution against Eriochrome black T at pH 11 (ammonium/
20 ammonium chloride buffer).
Evaluation:
% of ZnO = V t 16.27
wherem
V = ml of EDTA solution
25 t = titer of EDTA solution
