EP1137651A1

EP1137651A1 - 1-hydroxy-3-sulfonoalkane-1,1-diphosphonous acids

Info

Publication number: EP1137651A1
Application number: EP99958148A
Authority: EP
Inventors: Christoph Holzner; Roland KLEINSTÜCK; René GRAUPNER
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1998-12-11
Filing date: 1999-12-01
Publication date: 2001-10-04
Also published as: AU1558200A; DE19857251A1; KR20010087419A; CA2353863A1; WO2000035926A1; JP2002532506A

Abstract

The present invention relates to 1-hydroxy-3-sulfonopropane-1,1-diphosphonous acids, to phosphonate-containing mixtures which contain said acids, to a method for producing the same and to the application thereof as water treatment chemicals and sequestering agents.

Description

l-Hydroxy-3-sulfonoalkane-l, l-diphosphonic acids

The present invention relates to l-hydroxy-3-sulfonopropane-l, l-diphosphonic acids and phosphonate-containing mixtures containing these acids, a process for their preparation and their use as water treatment chemicals and

Sequestrant.

In industrial aqueous systems such as cooling water systems or steam-generating systems, but also in alkaline cleaning, for example in the food industry, water treatment chemicals or sequestering agents are used to protect against unwanted deposits of poorly soluble calcium salts (scale) and, if necessary, also against corrosion of the iron-containing materials.

l-Hydroxyalkane-l, l-diphosphonic acids with the structural element -C (OH) (PO ₃ H ₂ ) ₂ have long been known as water treatment chemicals. They are obtained by reacting carboxylic acids or carboxylic acid derivatives with inorganic compounds of trivalent phosphorus under dehydrating conditions and subsequent hydrolysis.

The best-known representative of l-hydroxyalkane-l, l-diphosphonic acids is 1-hydroxyethane-l, l-diphosphonic acid (HEDP) of the formula

CH ₃ -C (OH) (PO ₃ H ₂ ) ₂

HEDP is prepared from an acetyl derivative used in excess and an inorganic compound of trivalent phosphorus under initially dehydrating conditions, for example by reaction of 2.4 mol of acetic acid, 1 mol of PC1 ₃ and 0.6 mol of water, subsequent hydrolysis and removal of excess acetic acid (see US-A-4,060,546, Example 2). The most important The application for HEDP is the inhibition of scale formation in cooling water (PR Puckorius, SD Strauss; Power, May 1995, pages 17 to 28, especially page 18).

One advantage of HEDP is the one-step synthesis from inexpensive raw materials. A disadvantage of HEDP is the fact that it forms a very poorly soluble calcium salt. When the calcium content in the cooling water is high, the HEDP-Ca salt precipitates, so that the effective concentration of the inhibitor in the solution decreases and deposits of the HEDP-Ca salt can occur instead of the calcium carbonate deposits to be prevented.

In US-A-5 221 487 it is proposed ω-sulfono-l, l-diphosphonic acids of the formula

to be used as scale and corrosion inhibitors, where n can take integer values between 3 and 10 and X can be OH or NH ₂ . The

Compounds with X = OH are similar to HEDP in that both compounds have an l-hydroxy-l, l-diphosphonic acid group -C (OH) (PO ₃ H ₂ ) ₂ . One advantage of sulfonated phosphonic acids over HEDP is their significantly higher calcium tolerance. This is impressively demonstrated by Example 10 in US-A-5 221 487.

The calcium tolerance of a stone inhibitor can easily be determined in a standardized turbidity test by gradually increasing the concentration of the inhibitor at a fixed calcium concentration and a fixed pH until a clouding-causing precipitate occurs. The higher the inhibitor can be dosed without significant precipitation, the higher its calcium tolerance. A high calcium tolerance means that a high effective inhibitor concentration is set with an inhibitor in water with a high calcium content can be. This is a necessary but not sufficient condition for the use of an inhibitor in very hard water. The actual effectiveness of the inhibitor must also be proven in a stone inhibition test.

In US-A-5 221 487, however, a stone inhibition test is missing, which tests the effectiveness of the ω-

Sulfono-l, l-diphosphonic acids as stone inhibitors compared to HEDP shows. A technical advantage over the HEDP, as the closest prior art, is therefore not shown. A clear disadvantage of the sulfonated species from this publication compared to HEDP is their costly synthesis: expensive ω-bromoalkanecarboxylic acids are used as raw materials for the preparation of the l-hydroxy-ω-sulfonoalkane-l, l-diphosphonic acids. These are first reacted with phosphorus trichloride and water under dehydrating conditions to give ω-bromo-1-hydroxyalkane-l, l-diphosphonic acids. The bromine is then replaced by the sulfonic acid group by treating the reaction mixture with aqueous sodium sulfite solution and alkali metal hydroxide solution. The bromide that is split off remains dissolved in the aqueous product solution. It cannot be separated and recovered with reasonable effort.

Another l-hydroxy-ω-sulfonoalkane-l, l-diphosphonic acid of the formula

with n = 1

is mentioned in US-A-3,940,436 as a potential stone inhibitor (ibid., compound

No. 21 in column 8). The shortest possible synthetic route for this compound (ibid., Column 3, lines 1 to 29) begins with the dehydration of the solid HEDP sodium salt to the vinylidene diphosphonic acid sodium salt, which is expensive must be cleaned. The vinylidene diphosphonic acid sodium salt is then epoxidized with hydrogen peroxide in the presence of sodium tungstate as a catalyst. The epoxyethane-l, l-diphosphonic acid sodium salt obtained must then be reacted with sodium disulfite in aqueous solution (not with sulfuric acid, as described in error in US Pat. No. 3,940,436, Example XI).

The present invention was based on the object of providing a stone and corrosion inhibitor which

- Accessible from inexpensive raw materials and with high yield

- Has a good stone inhibition effect in a very wide range of water hardness and

- Especially in waters with a very high calcium concentration, it does not separate out poorly soluble calcium salts.

This object is achieved according to the invention by providing l-hydroxy-3-sulfonopropane-l, l-diphosphonic acids of the formula (I) and their salts,

where R ¹ and R ² independently of one another are hydrogen or methyl and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion,

preference being given to those compounds of the formula (I) in which

R ¹ and R ^{2 are} hydrogen and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion or those in which R ^{1 is} methyl and R ^{2 is} hydrogen and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion or those in which

R ^{1 is} hydrogen and R ^{2 is} methyl and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion

and the provision of phosphonate-containing mixtures, which are characterized in that they consist of the following components:

one or more sulfonic acids of formula (II) or their salts

one or more hydroxy acids of formula (III) or their salts

a phosphite of the formula (IV) = M'M ² HPO ₃

a phosphate of the formula (V) = M ¹ M ² M ³ PO 4

where R ¹ and R ^{2 are} independently hydrogen or methyl, M ¹ to M ⁵ and M ¹ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion, Z represents a group of the formula -COOM ¹ or -C (OH) (PO ₃ M ¹ M ² ) ₂ , n can assume integer values from 1 to 5 and the mean value for n over all compounds of types (II) and (III) is between 1 and 2. The mixture must contain at least one compound of the formula (II) with Z = -C (OH) (PO ₃ M'M ² ) ₂ and n = 1, that is to say a compound of the formula (I).

If appropriate, the mixtures according to the invention also contain a chloride of the formula (VI) = M'Cl or a hypophosphite of the formula (VII) = M ¹ H ₂ PO ₂ .

The preferred proportions of the individual components in the phosphonate-containing mixture are such that

at least 30%, particularly preferably at least 60% of the total phosphorus of the mixture is present in a compound of the formula (I),

- The molar ratio of the compounds of formula (II) to compounds of

Formula (III) is at least 5 to 1, particularly preferably at least 10 to 1,

- The molar ratio of the compounds of the formulas (II) and (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ to compounds of the formulas (II) and (III) with Z = COOM at least 1 to 1, especially is preferably at least 2.3 to 1,

a maximum of 50%, particularly preferably a maximum of 30% of the total phosphorus of the mixture is present in inorganic phosphorus compounds of the formulas (IV) and (V),

- A maximum of 15% of the total phosphorus of the mixture is present in a phosphate of the formula (V).

The proportion of phosphorus in the individual compounds of the mixture is determined by the relative intensity of the signals of the respective compounds in the ³¹ P-NMR

Spectrum determined (see Examples 1 and 2). The phosphonate of formula (I) shows a characteristic triplet with a coupling constant J _PH of 14.8 Hz (aqueous solution of the free acid at pH 0 to 1).

The molar ratio of compounds of type (II) to compounds of type (III) is in ^! H-NMR spectrum through the intensity ratio of the -CHR'-SO ₃ H signals

(Compounds of formula (II)) determined for the -CHR'-OH signals (compounds of formula (III)). For example, the signals of the compounds (II) with R ¹ = H show a chemical shift of 3.1 to 3.4 ppm, the signals of the compounds (III) with R ¹ = H show a chemical shift of 3.75 to 4.0 ppm, both measured against 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt in D ₂ O at a pH of 0 to 3.

The molar ratio of the compounds of the formulas (II) and (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ to compounds of the formulas (II) and (III) with Z = COOM is shown in the 'H-NMR Spectrum by the intensity ratio of the -CHR ² -C (OH) (PO ₃ M ₂ ) ₂ -

Signals to the -CHR ² -COOM signals determined. The former signals indicate, for example, for the case that R ² = H, ppm a chemical shift of 2.0 to 2.5, the latter for the case that R ² = H, a chemical shift of 2.5 to 3, 0 ppm, both measured against 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt in D ₂ O at a pH of 0 to 3.

The mean value of the coefficient n over all compounds of the formulas (II) and (III), that is to say the average degree of oligomerization n ^ ,,,,,, is likewise calculated from the Η-NMR spectrum. In the event that the radicals R ¹ and R ² both represent hydrogen (raw material acrylic acid), the intensities are those described above

-CH ₂ -SO ₃ H - and -CH ₂ -OH - signals added and multiplied by a factor of 2. The size obtained gives the relative signal intensity of the protons on the outside. The signal intensity of the protons inside is determined from the intensity of the very broad signals in the range from 1.3 to 2.3 ppm (at pH 6 to 7, compared to sodium 3- (trimethylsilyl) tetradeuteropropionic acid in D ₂ O) or in Range from 1.3 to 2.55 ppm (at pH 0 to 3, compared to 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt in D ₂ O). One calculates n ^^ according to the following formula:

ft _m i _tte i ⁼ 4/3 (intensity inner protons / intensity outer protons) + 1

The formula must be modified accordingly for methacrylic acid or crotonic acid as raw materials.

The compounds and mixtures according to the invention can be prepared in accordance with the following process steps, steps a), d) and e) being necessary, steps b), c), f) and g) being optional:

a) reaction of 1 mol of sulfur dioxide with at least 1 mol of water, at least 1 mol of a monovalent base and with 0.9 to 2 mol of an unsaturated carboxylic acid or a carboxylic acid mixture, carboxylic acids of the formula

are used and R ¹ and R ^{2 are} independently hydrogen or methyl;

b) optionally treating the reaction mixture from step a) with a strongly acidic cation exchanger in the H ⁺ form;

c) optionally dewatering the reaction mixture from step b);

d) reaction of the reaction mixture from a) or c) under dehydrating conditions with a P (III) -containing raw material, the molar amount of phosphorus used being 1.6 to 2.4 mol, optionally in the presence of an amine salt; e) hydrolysis of the reaction mixture from step d) with the addition of a sufficient amount of water or aqueous hydrochloric acid;

f) if necessary, a distillation to remove and recover volatile constituents;

g) if appropriate, recovery of the amine added in step a) or d) by alkalizing the reaction mixture with alkali metal hydroxide solution, separating off the released amine and reusing the amine in process step a) or d).

The unsaturated carboxylic acids to be used in process step a) are, for example, acrylic acid, methacrylic acid or crotonic acid, preferred are acrylic acid and crotonic acid, particularly preferably acrylic acid. Mixtures of the carboxylic acids mentioned can also be used, for example a mixture of acrylic acid and crotonic acid.

The monovalent base to be used in process step a) can be an alkali metal hydroxide, ammonia or an aliphatic primary, secondary or tertiary amine. Sodium hydroxide or a tertiary amine is preferably used, particularly preferably tributylamine.

The type of base used influences, inter alia, the proportion of oligomers in the end product. When using sodium hydroxide as the base, for example, significantly more oligomers are obtained than with tributylamine as the base.

The preferred molar amount of the base added must not be higher than the molar amount of sulfur dioxide and unsaturated carboxylic acid combined. Together with the minimum amount of base already defined, the preferred amount of base can be calculated using the following formula: Preferred number of moles of base = number of moles of SO ₂ + (factor ^■ number of moles of unsaturated carboxylic acid)

The factor in the above formula preferably takes values from 0 to 1, particularly preferably values from 0.3 to 0.9. Any amine salt possibly formed in process step a) can advantageously also be used in this amount in the later process step d).

The preferred amount of water to be used, if sodium hydroxide is used as the base, is 20 to 30 mol. If a tertiary amine is used as the base, the preferred amount of water is significantly smaller. The reason for this difference is on the one hand the different solubility of the salts, on the other hand the advantageous fact that dewatering according to process step c) can be saved if an amine is used as the base and if the amount of water in

Step a) is adapted to the substantially lower amount of water preferred in step d). If tributylamine is used as the base in step a) and as the P (III) -containing raw material in later process step d) PC1 ₃ , 3 to 5.8 mol, preferably 3.8 to 4.6 mol, are preferred in process step a) Water used. This amount of water already corresponds to the amount required in process step d) plus the amount of water (1 mol) consumed by chemical reaction in process step a), so that dewatering (process step c) and ion exchange (process step b) can be dispensed with.

The preferred amount of carboxylic acid to be used, if sodium hydroxide is used as the base, is 1 to 2 mol, particularly preferably 1.05 to 1.15. If a tertiary amine is used as the base, 0.90 to 0.98 mol of carboxylic acid are preferably used.

The molar amounts just mentioned are total amounts over the entire decay step a). The amount of base added and the amount of water can step-wise execution of process step a) can be divided: So it turned out to be advantageous, initially

1) React 1 mol SO ₂ with at least 1 mol water and at least 1 mol base and then this solution with

2) 0.9 to 2 mol of unsaturated carboxylic acid, the remaining base and the remaining water

to react. This division into two sub-steps 1) and 2) has the advantage that the pH can more easily be kept constant during the reaction with the unsaturated carboxylic acid. The preferred pH range for substep 2) is 3 to 8, particularly preferably pH 5 to 6.

Process step a) is particularly simple if

Sodium hydroxide is used as the base. Instead of reacting SO ₂ with sodium hydroxide solution and water, a solution of the commercially available sodium disulfite in water can be prepared directly here and reacted with a solution of carboxylic acid and sodium hydroxide in water. If the sodium disulfite solution is initially introduced and the sodium carboxylate solution is added, the proportion of oligomers in the end product is lower than if the sodium carboxylate solution is initially introduced and then the sodium disulfite solution is added.

The preferred reaction temperature for substep 1) is 0 to 40 ° C. For sub-step 2), 20 to 80 ° C. are preferred if an alkali metal hydroxide is used as the base, and 40 to 100 ° C. if an amine is used as the base.

Process step b) is only necessary if an alkali hydroxide was used as base in step a). In the ion exchange process, at least 50%, preferably at least 70%, of all alkali ions should be exchanged for H ⁺ ions. If an amine is used as the base, step b) can be omitted. A resin with SO ₃ H groups, such as LEWATIT® S 100, can be used as the ion exchanger.

Process step c) is necessary if the aqueous solution from process step a) or b) contains more than 4.8 mol of water per mol of SO used. Process step c) is usually necessary after process step b), since the eluates from the ion exchange resin usually contain too much water. If an amine is used as the base, step c) can be omitted, provided that no more than 5.8 mol of water was used in step a).

Dewatering is preferably carried out by distillation in vacuo at a pressure greater than or equal to 20 mbar and a bottom temperature of less than or equal to 90 ° C. A membrane process for concentrating the solution is also suitable.

The P (III) -containing raw material to be used in process step d) can be one of the following pure compounds or a mixture of the same compounds of trivalent phosphorus: phosphorus trichloride (PC1 ₃ ), phosphorus tribromide (PBr ₃ ), phosphorus trioxide (PO ₆ ), pyrophosphorous Acid (H ₄ P ₂ O ₅ ), Phosphorous acid

(H ₃ PO ₃ ) and monoalkyl, dialkyl and trialkyl esters of phosphorous acid, methyl and ethyl preferably being used as alkyl groups.

The raw material containing P (III) only gives the desired reaction under dehydrating conditions. Dehydrating conditions means that in the

Reaction mixture from step d) the initial molar ratio of the oxygen atoms bound to phosphorus (mol Op _-bound ) to all the phosphorus atoms present in the mixture (mol P _total ) must not be greater than 2.4. To calculate this initial molar ratio (mol Op _-bound ) / (mol P _total ), all oxygen atoms from the phosphorus-containing raw materials plus the oxygen atoms from possibly added water or from the water already present in the reaction mixture and divided by the number of P atoms from all added phosphorus-containing raw materials. The oxygen atoms from raw materials other than water and P (III) raw material are not counted.

Initial molar ratios (mol O _P-bonded ) / (mol P _total ) of 1 to 2.4 are preferred.

The suitable raw materials show as pure substances the following initial molar ratios (mol O _P _born and _s y ^(m ol Pg _^tal). Phosphorus trichloride and phosphorus trihalides bromide (0), phosphorus trioxide (1.5), pyrophosphoric acid (2.5 ), Phosphorous acid and its esters (3) According to the above condition, only phosphorus trioxide can be used as pure substances, all other substances must be mixed with another suitable P (III) raw material or in a mixture to achieve the desired molar ratio be used with water.

Preferred P (III) raw materials are the readily available and inexpensive chemicals phosphorus trichloride and phosphorous acid. If these preferred raw materials are used, an initial molar ratio (mol O _P. _Bound ) / (mol P _total ) of 1.4 to 1.8 is very particularly preferred. To achieve an initial molar ratio (mol O _P-bonded ) / (mol P _total ) ^of 1 _> 5, for example, 1 mol of phosphorus trichloride must be used together with 0.5 mol of phosphorous acid or together with 1.5 mol of water. Phosphorus trichloride, phosphorous acid and water can also be used in a combination of three. The use of 3/3 mol PC1 ₃ to 2/3 mol water and 1/3 mol H ₃ PO _{3 is} particularly advantageous because

Phosphorous acid can then be used in the form of a particularly inexpensive 70% aqueous solution, a waste product of fatty acid chlorination.

Reaction step d) can be carried out in the presence of an amine salt, the amine salt of the amine which has already been added in process step a) preferably being used. Was in process step a) in addition to Amine amount also adjusted the amount of water according to the conditions of process step d), only the P (III) -containing raw material needs to be added to the reaction mixture in step d).

If an amine is only added in process step d), the molar amount of the in

Process step d) added free acids plus the acids formed by hydrolysis of PC1 ₃ , PBr ₃ or P ₄ O _{6 are} greater than the molar amount of the free amine, ie the reaction mixture must have an excess of acid. If, for example, PC1 ₃ , water and H ₃ PO ₃ are used as raw materials, this condition can be expressed in the following inequality:

2 (mol number H ₃ PO ₃ ) + 2 (mol number water) - (mol number amine)> 0

The amine salt accelerates the reaction and leads to a higher yield of phosphonate in a shorter time. In the presence of an amine salt, the reaction in

Process step d) at 75 ° C for about one to three hours.

The temperature in process step d) can be 40 to 180 ° C. Reaction temperatures of 60 to 130 ° C are preferably used. If low-boiling PC1 _{3 is used} as raw material, the reaction temperature is 130 ° C

- Depending on the amount of water added and the amount of amine - under certain circumstances not immediately, but only after an approximately one-hour heating phase, during which a large part of the PC1 ₃ reacts to form non-volatile secondary products.

The order in which the raw materials are put together is arbitrary.

In process step e), the reaction mixture from process step d) is hydrolyzed. To this end, at least as much water or aqueous hydrochloric acid is added that all PCI or PBr bonds or P-O-P- used in process step d)

Bridges can be hydrolyzed. The one already used in process step d) The amount of water is taken into account. For example, if 1.5 mol PC1 ₃ and 1 mol water were used in addition to other raw materials in process step d), at least 2 mol water must be added again in process step c). The preferred amount of water is 1.1 to 20 times the minimum amount. The hydrolysis is preferably carried out at temperatures from 70 to 120 ° C., particularly preferably at 90 to 110 ° C. The hydrolysis can also be carried out at elevated pressure. The preferred time for the hydrolysis is one hour to 24 hours, particularly preferably 12 to 20 hours.

In optional process step f), volatile constituents of the reaction mixture, especially water and hydrogen chloride, are distilled off. For this purpose, the mixture is preferably heated to temperatures of up to 130 ° C. and aqueous hydrochloric acid is taken off at normal pressure or in vacuo.

If process step d) was carried out in the presence of an amine salt, the process is completed by process step g). For this purpose, the reaction mixture is adjusted to a pH greater than 7, preferably to pH 10-14, by adding alkali metal hydroxide solution, preferably sodium hydroxide solution. This frees the amine. In the case of trimethylamine, triethylamine or tripropylamine, it can be separated off by distillation. Due to their low water solubility, tributyl-, tripentyl- or trihexylamine can be separated from the phosphonate mixture very well by phase separation. The recovered amine can be reused in process step a) or d).

The substances and mixtures according to the invention can be used in many ways, for example as scale inhibitors and also as corrosion inhibitors. Areas of application of such agents can be, for example: water treatment (e.g. treatment of cooling water, process water, injection water for secondary oil production and water treatment in mining) as well as industrial and institutional cleaning applications (e.g. container and equipment cleaning in the food industry, bottle cleaning, institutional dishwashing detergents and detergents) . Such agents contain an l-hydroxy-3-sulfonopropane-l, l-diphosphonic acid of the formula (I) or a phosphonate-containing mixture of substances of the formulas (II) to (V), optionally also (II) to (VII), preferably in a total phosphonic acid concentration of 1 to 20%. Calculating the concentration of free

Phosphonic acid is described in Example 1, process step g). The agents can of course also contain the phosphonic acids in the form of their alkali metal, ammonium or alkylammonium salts.

The substances and mixtures according to the invention can be used alone or in combination with one or more substances which have proven useful for the particular application. Examples of such further components are:

Zinc salts, molybdates, borates, silicates, azoles (e.g. tolyl or benzotriazole), other phosphonic acids, homo-, co- and terpolymers based on acrylic acid, methacrylic acid, maleic acid, and possibly also co-monomers with phosphonate Containing sulfonate and / or hydroxy side groups, further polyaspartic acids, lignin sulfonates, tannins, phosphates, complexing agents, citric acid, tartaric acid, gluconic acid, surfactants, disinfectants, dispersants, biocides. For the person skilled in the art it goes without saying that instead of acids (e.g. "phosphonic acids") their salts ("phosphonates") and vice versa can also be used.

Substances and mixtures according to the invention, to which polyaspartic acids and / or their salts have been added as an additional component, have proven particularly advantageous. Preferred embodiments of the polyaspartic acids are described in DE 4 439 193 AI, which are also included in the present application. The present invention further relates to a method for water treatment, which is characterized in that the substances or mixtures according to the invention are introduced into the water to be treated.

Furthermore, the present invention relates to a process for alkaline cleaning, characterized in that the substances or mixtures according to the invention are used as incrustation inhibitors / sequestering agents.

The process for water treatment will be explained in the following using examples:

For example, the substances or mixtures according to the invention for preventing deposits and deposits when used in cooling systems with fresh water cooling are added to the incoming water in concentrations between about 0.1 and 1 omg / l of active ingredient.

In cooling circuits, the additives for stone and / or corrosion protection are often dosed depending on the quantity of the make-up water. The concentrations are between about 1 and 50 mg / 1 active ingredient in the circulating cooling water, the water hardness of which is usually much higher than that of fresh water cooling. Even higher water hardness often occurs - at least temporarily - in smaller cooling water systems, e.g. B. for air conditioners for hospitals or large office buildings, due to insufficient monitoring. Additives with a high calcium tolerance are particularly desirable for such systems. Dosages are around 10 to 500 mg / 1 active ingredient in the circulating cooling water.

In the case of distillative seawater desalination in MSF (multi stage flash) and VP (vapor compression) systems, incrustations on the heat exchanger surfaces are prevented by adding additives of about 1 to 5 mg / 1 active ingredient, added to the incoming seawater. The required dosages for RO (reverse osmosis) systems are generally significantly lower due to the lower maximum temperatures due to the process.

The process for using the substances and mixtures according to the invention in alkaline cleaning is explained as follows:

The active ingredient concentrations used to inhibit incrustation and sequestering in alkaline cleaning are based in particular on the technical and physical conditions, such as, for. B. pH values, residence times, temperatures, water hardness.

While in the weaker alkaline range (pH to about 10) at temperatures below 60 ° C and shorter residence times, active substance concentrations of well below 100 mg / 1, generally 5 to 80 mg / 1, are often sufficient, higher concentrations are

Alkali concentrations and temperatures dosages of e.g. T. over 100 mg / 1 to 1000 mg / 1 required.

The substances and mixtures according to the invention have the following advantages over the commercially used product HEDP:

they do not form poorly soluble calcium salts in water with a very high calcium concentration. Their calcium tolerance is significantly higher, which is evidenced by the low turbidity values in Table 1 from Example 3;

They are the more effective stone inhibitors in water with a total hardness of 300 to 600 ppm CaCO ₃ , because they prevent the formation of tight deposits (= scale) in these waters, which are oversaturated with calcium carbonate, even at a lower dose than HEDP (see the characteristic - signs * for scale in tables 2 and 3). Furthermore, this is

Water the proportion of calcium ions caused by the stone inhibitor in solution can be maintained (= residual hardness RH [%]), when used significantly higher than when using HEDP (see tables 2 and 3). Even very hard water with a total hardness of 1200 ppm CaCO ₃ is stabilized by the inhibitors according to the invention at a correspondingly high dosage to give a clear solution, while HEDP, due to its low calcium tolerance, leads to the precipitation of poorly soluble calcium salts under the same conditions (see Table 4, inhibitor concentration 400 mg / 1).

Compared to the l-hydroxy-ω-sulfonoalkane-l, l-di-phosphonic acids of the formula proposed in the literature

With n = 1 and n = 3 to 10 and X = OH, the substances and mixtures according to the invention have the following advantages:

- They can be produced in good yields and from inexpensive raw materials;

they are the more effective stone inhibitors in water with a total hardness of 300 to 600 ppm CaCO ₃ , because they hold a larger proportion of potassium ions in solution than the previously described l-hydroxy-ω- even at very low doses of 2 to 5 mg / 1 inhibitor. sulfonoalkane-l, l-diphosphonic acids of the above formula. This is evidenced by the measured residual hardnesses in Tables 2 and 3 (compare substance from example 1 (according to the invention) with the substances from comparison examples 3 and 4 (previously described)). In addition, the agents according to the invention prevent the formation of tight deposits (= scale) in water with 600 ppm CaCO ₃ even at a lower level

Dosage as the above-described l-hydroxy-ω-sulfonoalkane-l, l-di-phosphonic acids (see the indicator * for scale in Table 3). The process for the production of the substances according to the invention has the formula of the formula for the 1-hydroxy-ω-sulfonoalkane-1,1-diphosphonic acids already described above

with n = 1 and n = 3 to 10 and X = OH the following advantages:

it gives the previously unknown compounds of the above formula with n = 2 in good yield;

it provides good stone inhibitors with very high calcium tolerance;

it also provides additional methyl-substituted compounds of the formula I where R ¹ or R ² is methyl;

Both production processes mentioned in the literature for the literature-known l-hydroxy-ω-sulfonoalkane-l, l-diphosphonic acids of the above formula with n = 1 and n = 3 to 10 do not lead to the compounds of formula (I) according to the invention.

For example, the above-described production process for the compounds with n = 3 to 10 from US Pat. No. 5,221,487 cannot be extended to compounds with n = 2. The mixtures obtained in this experiment contain a component of the formula (I) either not at all or only in a very low concentration (see comparative examples 1 and 2). Accordingly, in all the tests carried out, these mixtures show a much poorer stone inhibition effect than the mixtures according to the invention from Example 1 (see Tables 1 to 4 under “Substance Comparative Example 1 (C ₃ Framework)”). The preparation process likewise described above for the compounds with n = 1 from US Pat. No. 3,940,436 is in principle not suitable for the preparation of compounds of the formula (I), since sulfono group and -C (OH) (PO ₃ H ₂ ) ₂ - Group because of the synthetic route via the epoxyethane-l, l-diphosphonic acid sodium salt can only be separated from one another by a maximum of one CH ₂ group, but not by two CH ₂ groups.

The production process according to the invention is thus the only one which enables the preparation of compounds of the formula (I) in good yields.

The invention is illustrated by the following examples. For the description of the process steps, see above.

Examples

example 1

Implementation of acrylic acid according to the invention with tributylamine, SO ₂ , water and phosphorus trichloride

Process step a), sub-step 1)

740 g (4 mol) of tributylamine and 252 g (14 mol) of water are placed in a 2 1 multi-necked flask equipped with a stirrer, internal thermometer, pH electrode, gas inlet tube with glass frit, reflux condenser and gas outlet tube connected to it. Sulfur dioxide is introduced into this two-phase mixture with vigorous stirring at 20 ° C. to 30 ° C. until the mixture becomes single-phase and a pH of 4 is measured. The weight of the reaction mixture gives an increase in mass of 263.6 g, which means that 4.12 mol SO _{2 have been} absorbed. In order to set a molar ratio of sulfur dioxide / tributylamine / water of 1/1 / 3.5, 22 g of tributylamine and 7.5 g of water are added to the mixture. 312 g of this total mixture correspond to the quantities of 1 mol of sulfur dioxide, 1 mol of tributylamine and 3.5 mol of water.

Process step a), sub-step 2)

312 g of the above solution are placed in a 1 1 multi-necked flask with stirrer, internal thermometer, 2 dropping funnels, pH electrode and reflux condenser with an air line connected to it. The mixture is preheated to 60 ° C. 72.42 g (1 mol) of acrylic acid (99.5%) and 78.5 g (0.42 mol) of tributylamine are then added dropwise from this at this temperature from two separate dropping funnels. The pH of the reaction mixture is between 5 and 5.5. After the dropwise addition, stirring is continued at 60 ° C. for at least two hours.

An iodometric sulfite determination shows that after one hour of stirring 87.7%, after 2 h stirring time already 97.6% of the SO used, can no longer be detected as sulfite. 462.9 g of the mixture obtained correspond to amounts of originally 1 mol of SO ₂ , 1 mol of acrylic acid, 1.42 mol of amine and 3.5 mol of water. Since one mole of water per mole of SO _{2 was} already consumed by chemical reaction in sub-step 1), the amount of free water contained is only 3.5-1

= 2.5 mol. The amount of free water is decisive for the following process step d).

Sodium hydroxide solution is added to a sample of the solution and, after the amine has been separated off, concentrated on a rotary evaporator at 20 mbar and 90 ° C. A ^] H NMR

Spectrum of this sample (with 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance at 0 ppm) shows the compound (II) with Z = COOH, R ¹ and R ² = H and n = 1 as two triplets at 2.58 ppm (for the -CH, -COONa- group) and 3.13 ppm (for the -CH ₂ -SO ₃ Na group). At 3.65 to 3.85 ppm, a signal group for the different -CH ₂ -OH species is visible. The molar ratio of -CH ₂ -SO ₃ Na to -CH ₂ -OH is 42. The average degree of oligomerization n ^ ,,,,, is very close to 1, but cannot be determined exactly, since residues of tributylamine interfere in the spectrum.

Process step d)

126.62 g of the above reaction mixture and 5.04 g

(0.28 mol) of water initially charged, blanketed with nitrogen and heated to 60 ° C. The mixture presented corresponds to the original amount: 0.274 mol SO ₂ , 0.388 mol amine, 0.274 mol acrylic acid and 1.236 mol water, the amount of free water being only 0.964 mol. 77.0 g of this mixture are then added with stirring and cooling within 30 min at a temperature of 60 to 70 ° C

(0.561 mol) of phosphorus trichloride was added dropwise. The amount of phosphorus tri Chloride is calculated so that the molar ratio of the amount of phosphorus used to the amount of SO _{2 used is} 2.05, or the molar ratio of the amount of SO ₂ used to the amount of phosphorus used is 0.49. Furthermore, the molar ratio of free water before the PCl ₃ addition to the phosphorus used is 1.72. After the PCl ₃ addition, the reaction mixture is kept at 70 to for 3 hours

80 ° C stirred.

Process step e)

Then slowly drop in with stirring, after the initial has subsided

HCl gas evolution also faster, add 280 ml of water and keep the mixture at 100 ° C for 18 hours. A total of 1.07 mol HC1 and 0.02 mol H ₃ PO _{3 were} detected in the absorption vessel with 1 1 water for escaping HC1 and PCl ₃ gas (see process step d)).

Process step g)

The reaction mixture is cooled to 40 to 50 ° C. and 136 g (1.53 mol) of 45% sodium hydroxide solution are added with stirring. The 60 ° C warm, two-phase mixture is transferred to a separatory funnel. The separating lighter, more organic

Phase consists of 70.4 g of tributylamine, which can be used again in the synthesis without further purification (the degree of recovery for tributylamine in this experiment is 97.9%).

The heavier aqueous phase (490.4 g) is the desired phosphonate mixture. A phosphorus content of the solution of 3.41% is calculated from the mass of the aqueous phase, the molar amount of PC1 _{3 used} and the loss of PCl ₃ by evaporation.

According to the ³¹ P-NMR analysis, 72.1% of the total phosphorus is present in the aqueous phase as a phosphonate of the formula (I) with R ¹ and R ² = H. (The percentages from the NMR spectra here correspond to the relative ones as in the following text Area percentages under the signals). The compound (I) appears in the ³¹ P-NMR spectrum as a triplet with a chemical shift of 18.6 ppm. Another triplet with 2.8% of the total signal intensity is shown at 19.2 ppm. This signal can presumably be assigned to the compound (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ , R ¹ and R ² = H and n = 1. A phosphite of the formula (IV) can also be detected

3.8 ppm (5.4% of the phosphorus) and a phosphate of the formula (V) at 3.4 ppm (10.2% of the phosphorus). Together with other phosphonates of unknown structure, a total of 84.4% of the phosphorus is present in phosphonates. From this total phosphonate content in mol% according to ³¹ P-NMR analysis, the calculated total phosphorus content of the solution of 3.41 mass% and the molecular weight of the compound (I) with M and R = H of 300.1 g / mol, a phosphonic acid content of 13.9 mass% is calculated. This concentration is used to calculate the sample weight in the application test.

A sample of the aqueous phase is adjusted to pH 2 to 3 with hydrochloric acid, evaporated and dissolved in D ₂ O. An ^] H-NMR spectrum of this sample (with sodium 3- (trimethylsilyl) tetradeuteropropionic acid as internal reference substance at 0 ppm) shows two signal groups which predominantly originate from compound (I) with R ¹ and R ² = H: a multiple «At 2.37 ppm (for the -CH ₂ -C (OH) (PO ₃ M ₂ ) ₂ groups of compound (I) and too little of compound (III) with Z =

-C (OH) (PO ₃ M ₂ ) ₂ , R ¹ and R ² = H and and n = 1) and another multiple at 3.24 ppm (for the -CH ₂ -SO ₃ M groups of compound (I) and too little of compound (II) with Z = COOH, R ¹ and R ² = H and and n = 1). Two lower intensity triplets at 2.6 and 2.75 ppm represent the -CH ₂ -COOH groups of compound (III) with Z = COOH, R ¹ and R ² = H and and n = 1 and the analog, respectively Compound (II). The -CH ₂ -OH groups of the compounds of formula (III) appear as a signal group at 3.75 to 4 ppm. Residues of tributylammonium ions appear at 0.93, 1.38, 1.7 and 3.1 ppm. The molar ratio of the compounds of the formula (II) to compounds of the formula (III) determined from the signal intensities is 18.8 (= molar ratio -CH ₂ -SO ₃ M / -CH ₂ -OH). The molar ratio of the compounds of the formulas (II) and (III) with Z - -C (OH) (PO ₃ M ₂ ) ₂ to compounds of the Formulas (II) and (III) with Z = COOM is 5.3 (= molar ratio -C (OH) (PO ₃ M ₂ ) ₂ / COOM).

A ¹³ C-NMR spectrum of the acidic mixture (solvent D ₂ O, with 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance, adjusted to 1.7 ppm) shows the following chemical shifts and coupling constants at "H decoupling: For compound (I) with R ¹ and R ² = H: 1-C: 76.3 ppm (t, 'J _CP 149.8 Hz), 2-C: 33.0 ppm (s), 3-C: 50.6 ppm (t, J _CP 6.6 Hz) For compound (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ , R ¹ and R ² = H and n = 1: 1- C: 76.6 ppm (t, ^] J _CP 149.1 Hz), 2-C: 35.7 ppm (s), 3-C: 62.1 ppm (t, ³ J _CP 7.3 Hz).

Example 2

Implementation of acrylic acid according to the invention with sodium hydroxide solution, sodium disulfite, water and phosphorus trichloride

Process step a)

80.1 g (1.1 mol) of acrylic acid (99%) are placed in a ventilated apparatus and with stirring at 20 to 25 ° C within 30 min with 197.6 g (1.0 mol)

20.24% sodium hydroxide solution added. The final pH of the sodium acrylate solution is 6.5.

95.1 g (0.5 mol) of sodium disulfite are dissolved in 300 ml of water in a multi-necked flask equipped with a stirrer, dropping funnel, internal thermometer, pH electrode, reflux condenser and connected air line. The pH of the solution is adjusted to pH 4.5 with about 5 ml of 20% sodium hydroxide solution. With stirring and cooling, the above sodium acrylate solution is then added dropwise at 35 to 40 ° C. within 1.5 h. The final pH of the reaction mixture is 6.3. The mixture is stirred for a further hour at 30 to 35 ° C. An iodometric sulfite determination shows that 95.9% of the sulfite used is no longer detectable after one hour of stirring. A sample of the solution is concentrated on a rotary evaporator at 25 mbar and 90 ° C heating bath temperature. An 'H-NMR spectrum of this sample in D ₂ O indicates that acrylic acid is no longer present in the mixture. At 3.1 to 3.3 ppm (against 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance, set to 0 ppm) the -CH ₂ -SO ₃ Na groups are different

Species visible. At 3.8 ppm the triplet of a -CH ₂ -OH species appears, at 4.3 to 4.4 ppm a signal group for various -CH ₂ -O-CO group-containing compounds. The molar ratio of -CH ₂ -SO ₃ Na to (-CH ₂ -OH + -CH ₂ -O-CO-) is 7.1. The very broad signals for the inner protons of the various oligomers are found at 1.3 to 2.3 ppm. The average degree of oligomerization r ,, _; ,,,,, is calculated as 1.18.

The total mixture corresponds to the amounts of 1 mol of sulfur dioxide, 2.025 mol of sodium hydroxide solution, 1.1 mol of acrylic acid and 25.6 mol of water.

Process step b)

The solution from process step a) is passed through a column with 1.4 1 LEWATIT® S 100 ion exchanger (acid form).

Process step c)

The eluate from process step b) is first dewatered on a rotary evaporator at a heating bath temperature of 60 ° C. and a pressure of 50 mbar, and finally at 90 ° C. and 20 mbar for a further 10 minutes. 161 g of a solid residue are obtained. A titration after

Karl Fischer indicates a water content of 13.4%. Titration with sodium hydroxide solution gives a difference of 5.435 mmol COOH groups per g substance from the difference between the first and second equivalence point. Only half of the -SO ₃ Na groups have been converted into -SO ₃ H groups. A sample of the solution is concentrated on a rotary evaporator at 25 mbar and 90 ° C heating bath temperature. An 'H-NMR spectrum of this sample in D, O shows a triplet for the -CH ₂ - at 3.1 to 3.3 ppm (against 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance, set to 0 ppm). SO ₃ M group of compound (II) with Z = COOH, R ¹ and R ² = H and n = 1, and in the

Edge zones of the main signal as a broadening of the -CH ₂ -SO ₃ M groups of analog species with n> 1. At 3.85 ppm the triplet of a -CH ₂ -OH species appears, at 4.25 to 4.45 ppm a signal group for various -CH ₂ -O-CO group-containing compounds. The molar ratio of -CH ₂ -SO ₃ M to (-CH ₂ -OH + -CH ₂ -O-CO-) is 7.9. The very broad signals for the inner protons of the various oligomers are at 1.5 to 2.55 ppm. The average degree of oligomerization n- _n i _tt ,,] is calculated to be 1.18 (no change compared to the analysis after process step a)).

Process step d)

18.42 g of the reaction mixture from process step c), containing 0.1 mol COOH groups and 2.47 g (0.137 mol) water, are additionally 93 g (0.163 mol) of water and 37.08 g

(0.2 mol) tributylamine submitted. When heating to 60 ° C under nitrogen, two liquid phases are formed.

The mixture presented corresponds to the use amounts of originally 0.091 mol SO ₂ and 0.1 mol acrylic acid and currently 0.2 mol amine and 0.3 mol water. To this

Mixture is then added dropwise with stirring and cooling within 21 min at a temperature of 60 to 65 ° C 27.5 g (0.2 mol) of phosphorus trichloride. The added amount of phosphorus is calculated so that the molar ratio of amount of phosphorus employed to inserted SO ₂ amount 2.2, or the molar ratio of SO ₂ amount is employed to inserted amount of phosphorus 0.46.

Furthermore, the molar ratio of free water before adding PCl ₃ to put phosphorus 1.5. After the PCl ₃ addition, the reaction mixture is stirred at 75 ° C. for a further 21 hours.

Process step e)

100 ml of water are then added dropwise at 30 to 40 ° C. with stirring over a period of 15 minutes, and the mixture is kept at 75 ° C. for a further 21 hours. Then 40 ml of water are added and traces of a suspended matter are filtered off.

Process step g)

70 g (0.79 mol) of 45% sodium hydroxide solution are added to the filtrate. The 60 ° C warm, two-phase mixture is transferred to a separatory funnel. The lighter, organic phase that separates consists of tributylamine (the degree of recovery for tributylamine in this experiment is approximately 94%), which can be used again in the synthesis without further purification

The heavier aqueous phase (216 g) is the desired phosphonate mixture. From the mass of the aqueous phase, the molar amount of PC1 _{3 used} and the estimated PCl ₃ loss of 8% by evaporation and sampling for analysis, a phosphorus content of the solution of 2.72% is calculated.

According to the ³¹ P-NMR analysis, 37.6% of the total phosphorus is present in the aqueous phase as a phosphonate of the formula (I) with R ¹ and R ² = H. This connection

31, shows up in the P-NMR spectrum as a triplet (J _PH = 12.8 Hz) with a chemical

Displacement of 18.7 ppm. Another triplet with 7.7% of the total signal intensity is shown at 19.3 ppm. This signal can presumably be assigned to the compound (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ , R ¹ and R ² = H and n = 1. A phosphite of the formula (IV) at 3.75 ppm (1.1% of the phosphorus) and a phosphate of the formula (V) at 6.0 ppm (19.7% of the phosphorus) are also detectable. Along with other phosphonates of unknown structure, a total of 78.3% of the phosphorus is present in phosphonates.

Example 3

Implementation of crotonic acid according to the invention with tributylamine, SO ₂ , water and phosphorus trichloride

Process step a), sub-step 1)

185 g (1 mol) of tributylamine and 63 g (3.5 mol) of water are placed in a 500 ml multi-necked flask equipped with a stirrer, internal thermometer, gas inlet tube with glass frit, reflux condenser and connected gas outlet tube. Nitrogen is first introduced into this two-phase mixture, then sulfur dioxide with vigorous stirring at 25 ° C. to 30 ° C. until the second liquid phase disappears and the color of the mixture changes from colorless to yellow. Weighing out the reaction mixture gives an increase in mass of 65.5 g, which means that 1.02 mol of SO _{2 have been} absorbed. In order to set a molar ratio of sulfur dioxide / tributylamine / water of 1/1 / 3.5, 4.33 g of tributylamine and 1.47 g of water are added to the mixture. 312 g of this total mixture correspond to the amounts of 1 mol of sulfur dioxide, 1 mol of tributylamine and 3.5 mol of water.

Process step a), sub-step 2)

312 g of the above solution are placed in a 1 liter multi-necked flask equipped with a stirrer, internal thermometer, dropping funnel and pH electrode. The mixture is preheated to 60 ° C.

87.85 g (1 mol) of crotonic acid (98%) are melted together with 16.2 g (0.9 mol) of water in a beaker and at 60 ° C. with water cooling with 74.0 g

(0.40 mol) tributylamine added. This single phase mixture is made within Was added dropwise at 60 ° C. to the above solution from process step a), sub-step 2). The mixture is left to react at 60 ° C. for 23 h and at 80 ° C. for 5 h. The pH of the reaction mixture after the reaction is 5.8. The mixture obtained (490 g) corresponds to the initial use of 1 mol SO ₂ , 1 mol crotonic acid, 1.4 mol amine and 4.4 mol water. Since one mole of water per mole of SO _{2 was} already consumed by chemical reaction in sub-step 1), the amount of free water contained is only 3.4 moles. The amount of free water is decisive for the following process step d).

A sample of the solution is mixed with sodium hydroxide solution and after the

Amines on a rotary evaporator at 20 mbar and 90 ° C concentrated. A NMR NMR spectrum of this sample (with 3 - (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance at 0 ppm) shows for the compound (II) with Z = COOH, R ¹ = methyl, R ² = H and n = 1 the following signals: -CH ₃ : 1, 31 ppm (d), -CFI ₂ -COONa: 2.22 ppm (dd) and 2.84 ppm (dd), -CH-SO ₃ Na: 3.26 ppm (m).

By-products containing -CH-OH groups or oligomers cannot be detected.

Process step d)

In a 0.5 1 four-necked flask with stirrer, internal thermometer, dropping funnel, reflux condenser (coolant temperature -15 ° C), connected gas discharge pipe, safety vessel and absorption vessel with 1 1 water to collect HC1 and entrained PCI3, 196 g of the above reaction mixture are introduced, with Nitrogen superimposed and heated to 60 ° C. The mixture presented corresponds

Amounts originally used: 0.4 mol SO ₂ , 0.4 mol crotonic acid, 0.56 mol amine and 1.76 mol water, the amount of free water being only 1.36 mol. 110 g (0.8 mol) of phosphorus trichloride are then added dropwise to this mixture with stirring and cooling at 35 to 60 ° C. in the course of 35 minutes. The added amount of phosphorus is calculated such that the molar ratio of employed amount of phosphorus to be inserted SO ₂ quantity 2, or the Molar ratio of the amount of SO ₂ used to the amount of phosphorus used is 0.5. Furthermore, the molar ratio of free water before the PCl ₃ addition to the phosphorus used is 1.7. After the addition of PCl ₃ , the reaction mixture is stirred at 70 to 80 ° C. for a further 3 hours.

Process step e)

400 ml of water are then slowly added dropwise while stirring, after the initial HCl gas evolution has subsided, and the mixture is kept at 100 ° C. for a further 18 h. A total of 1.69 mol HC1 and 0.072 mol H ₃ PO _{3 were} detected in the absorption vessel with 1 1 water for escaping HC1 and PCl ₃ gas (see process step d)).

Process step g)

The reaction mixture is cooled to 60 ° C. and 213 g (2.4 mol) of 45% sodium hydroxide solution are added with stirring. The 60 ° C warm, two-phase mixture is transferred to a separatory funnel. The lighter, organic phase which separates out consists of 102.5 g of tributylamine, which can be used again in the synthesis without further purification (the degree of recovery for tributylamine in this experiment is 98.9%).

The heavier aqueous phase (724.5 g) is the desired phosphonate mixture. A phosphorus content of the solution of 3.11% is calculated from the mass of the aqueous phase, the molar amount of PC1 _{3 used} and the PCl ₃ loss by evaporation.

31

According to P-NMR analysis, 52.2% of the total phosphorus is present in the aqueous phase as a phosphonate of the formula (I) with R ¹ = methyl, R ² = H. This connection shows

31 in the P-NMR spectrum as multiples and with Η decoupling in the form of two closely spaced signals at 18.9 ppm and 19.0 ppm. Furthermore, a phosphite of the formula (IV) at 3.7 ppm (11.1% of the phosphorus) and a are detectable Phosphate of formula (V) at 4.5 ppm (18.2% of the phosphorus). Together with other phosphonates of unknown structure, a total of 70.7% of the phosphorus is present in phosphonates.

Example 4

Implementation of methacrylic acid according to the invention with tributylamine, SO ₂ , water and phosphorus trichloride

Analogously to Example 3, methacrylic acid is used instead of crotonic acid.

In process step a), sub-step 2), the methacrylic acid is reacted at 80 ° C. from the start. A sample of the reaction solution obtained there is mixed with sodium hydroxide solution and, after the amine has been separated off on a rotary evaporator, concentrated at 20 mbar and 90 ° C. A Η NMR spectrum of this sample (with sodium 3- (trimethylsilyl) tetradeuteropropionic acid as internal reference substance at 0 ppm) shows for compound (II) with Z = COOH, R ¹ = H, R ² = methyl and n = 1 the following signals to: -CH ₃ : 1.23 ppm (d), -CH-COONa: approx.2.75 ppm (m), -CH ₂ - SO ₃ Na: 3.31 ppm (dd) and approx 2.85 (m).

After process step g), 960.6 g of aqueous phase are obtained. A phosphorus content of the solution of 2.93% is calculated from the mass of the aqueous phase, the molar amount of PC1 _{3 used} and the PCl ₃ loss due to evaporation.

31 According to P-NMR analysis, 39.1% of the total phosphorus is present in the aqueous phase as a phosphonate of the formula (I) with R ¹¹ == HH and RR ²² = methyl. This compound shows two multiplets in the ^J 'P NMR spectrum, and two in' H decoupling

Doublets at 19.4 ppm and 18.0 ppm with a ² J _PP coupling constant of respectively

Pass 22.3 Hz. A phosphite of the formula (IV) at 3.7 ppm (29.4% of the phosphorus) and a phosphate of the formula (V) at 4.6 ppm are also detectable (16.1% of the phosphorus). Together with other phosphonates of unknown structure, a total of 54.5% of the phosphorus is present in phosphonates.

Comparative Example 1

Analogously to Example 7 from US Pat. No. 5,221,487, 3-bromopropionic acid is first reacted with PC1 ₃ and water, then with sodium sulfite and KOH. In comparison to this example 7, the amounts of raw materials used are tripled.

13.8 g (90 mmol) of 3-bromopropionic acid and 4.05 g (225 mmol) of water are placed in a multi-necked flask equipped with a stirrer, dropping funnel, reflux condenser and gas discharge tube and heated to 40 ° C. At a temperature of 40 to 50 ° C, 20.7 g (150 mmol) of phosphorus trichloride are added dropwise with stirring within 20 min. After the addition has ended, the mixture is heated under reflux in an oil bath at 150 ° C. for 3 hours. The mass becomes solid at times. After 3 h, the mixture is allowed to cool to room temperature and a solution of 9.9 g (150 mmol) of 85% potassium hydroxide and 11.3 g (90 mol) of sodium sulfite in 90 g of water are added dropwise with cooling in the course of 15 min. The mixture is then heated to 100 ° C. for 19 hours with stirring. The clear solution has a final pH of 4.85 and is evaporated to dryness. 38 g of a solid are obtained.

The ³¹ P-NMR spectrum (solvent D ₂ O) shows a triplet characteristic of the -CH ₂ -C (OH) (PO ₃ M ₂ ) ₂ group of achiral compounds at 18.8 ppm. Only 13.2% of the phosphorus is contained in this -CH ₂ -C (OH) (PO ₃ M ₂ ) ₂ group. A compound of the formula can also be used

in the Η-decoupled ³¹ P-NMR spectrum by two doublets at 37.2 ppm (endocyclic phosphor) and 16.7 ppm (exocyclic phosphor) with a coupling constant of ² J _PP of 35.9 Hz. This compound contains 19.0% of the phosphorus. Together with other phosphonates of unknown structure, a total of 93.4% of the phosphorus is present in phosphonates. The structure of most of the phosphonates contained cannot be assigned. 5.8% of the phosphorus is present as the phosphate of the formula (V), the chemical shift of which is 1.0 ppm.

An H-NMR spectrum of this sample (with 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance at 0 ppm) shows two triplets, predominantly of compound (II) with Z = COOM, R ¹ and R ² = H and n = 1: one triplet at 2.62 ppm (for the -CH ₂ -COOM group of this compound) and another triplet at 3.15 ppm (for the -CH ₂ -SO ₃ M group of this compound binding). In the -CH ₂ -SO ₃ M-typical range from 3 to 3.3 ppm, no further signal can be seen except for the triplet just mentioned. This means that the majority of the sulfonic acid groups are not in a compound of type (I) but in a compound of formula (II) with Z = COOM. A compound of type (I) should result in a complicated multiple (see Example 1), but not a simple triplet, due to the P, H coupling for the protons of the -CH ₂ -SO ₃ M group. The -CH ₂ -OH groups of the compounds of formula (III) appear as two triplets at 3.75 to 4 ppm. The molar ratio of the compounds of formula (II) to compounds of formula (III) determined from the signal intensities is 4 (= molar ratio -CH ₂ -SO ₃ M / -CH ₂ -OH).

Comparative Example 2

Analogously to Comparative Example 1, 3-bromopropionic acid is first reacted with PC1 ₃ and water, then with an increased amount of sodium sulfite and KOH. The reaction is carried out as in Comparative Example 1, with the difference that 210 mmol of KOH are used instead of 150 mmol and 145 mmol of sodium sulfite instead of 90 mmol. The final reaction mixture has a pH of 6.45 before evaporation.

The ^3! P-NMR spectrum (solvent D ₂ O) shows two triplets characteristic of the -CH, -C (OH) (PO ₃ M ₂ ) ₂ groups of achiral compounds. One at 18.7 ppm, which has 2.9% of the total phosphor signal intensity and one at 19.5 ppm, which shows 15.4% of the total signal intensity. By metering in a sample from Example 1 and measuring the sample mixture again, it is found that the originally smaller signal has clearly increased in intensity with 2.9% of the phosphorus. It thus corresponds to the compound of formula (I) with R ¹ and R ² = H and n = 1. The originally larger signal with 15.4% of the phosphorus can be the compound of formula (III) with Z = -C (OH ) (PO ₃ M ₂ ) ₂ , R ¹ and R ² = H and n = 1 assign. Furthermore, a compound of the formula can be found in the pure sample from comparative example 2

to prove. This compound contains 11.5% of the phosphorus. Together with other phosphonates of unknown structure, a total of 91.0% of the phosphorus is present in phosphonates. The majority of the phosphonates contained cannot be assigned here either in terms of their structure. 8.0% of the phosphorus is present as phosphate of the formula (V), the chemical shift of which is 2.9 ppm.

An H-NMR spectrum of this sample (with 3- (trimethylsilyl) tetradeuteropropionic acid sodium salt as internal reference substance at 0 ppm) shows two triplets, which are predominantly composed of compound (II) with Z = COOH, R ¹ and R ² = H and n = 1: one triplet at 2.60 ppm (for the -CH ₂ -COOM group of this compound (II)) and another triplet at 3.16 ppm (for the -CH ₂ -SO ₃ M group this connection (II)). In the -CH ₂ -SO ₃ M-typical range from 3 to 3.3 ppm, no further signal can be seen except for the triplet just mentioned. This means that again the majority of the sulfonic acid groups are not in a compound of type (I) but in a compound of formula (II) with Z = COOM. The -CH ₂ - OH groups of the compounds of the formula (III) appear as two triplets

3.75 to 4 ppm. The molar ratio of the compounds of formula (II) to compounds of formula (III) determined from the signal intensities is 7.7 (= molar ratio -CH ₂ -SO ₃ M / -CPL-OH).

Comparative Example 3

Analogously to Example 5 from US Pat. No. 5,221,487, the homologous 4-bromobutyric acid is first reacted with PC1 ₃ and water, then with sodium sulfite and KOH instead of 5-bromovaleric acid. The amounts of raw materials used are increased sixfold compared to this example.

14.0 g (84 mmol) of 4-bromobutyric acid and 3.8 g (210 mmol) of water are placed in a multi-necked flask equipped with a stirrer, dropping funnel, reflux condenser and gas discharge tube and heated to 40 ° C. At a temperature of 40 to 50 ° C 19.0 g (138 mmol) of phosphorus trichloride are added dropwise with stirring within 20 minutes. After the addition has ended, the mixture is heated under reflux in an oil bath at 130 ° C. for 3 hours. The inside temperature is approx. 120 ° C. After 3 h, the mixture is allowed to cool to room temperature and a solution of 8.9 g (138 mmol) of 86.7% potassium hydroxide and 10.8 g (85.6 mol) is added dropwise with cooling at 25 to 30 ° C. in the course of 15 min. Sodium sulfite in 90 g of water. The reaction mixture is alkaline immediately after the solution is added dropwise. After heating to 95-100 ° C., the pH drops to 5 to 6. The mixture is heated to 100 ° C. with stirring for 19 hours. The clear solution obtained (124.3 g) has a final pH of 4.7.

The ³¹ P NMR spectrum (solvent D ₂ O) shows one for the

-CH ₂ -C (OH) (PO ₃ M ₂ ) ₂ group of achiral compounds characteristic triplet 19.1 ppm. This group contains only 6.0% of the phosphorus. A compound of the formula can also be used

in the Η-decoupled ³¹ P-NMR spectrum by two doublets at 15.0 ppm (endocyclic phosphorus) and 17.7 ppm (exocyclic phosphorus) with a coupling constant of ² J _PP of 25.4 Hz. This compound contains 27.0% of the phosphorus. Together with other phosphonates of unknown structure, a total of 90.4% of the phosphorus is present in phosphonates. The structure of most of the phosphonates contained cannot be assigned. 9.6% of the phosphorus is present as phosphate of the formula (V), the chemical shift of which is 0.7 ppm.

Comparative Example 4

Analogously to Example 5 from US Pat. No. 5,221,487, 5-bromovaleric acid is first reacted with PC1 ₃ and water, then with sodium sulfite and KOH. In comparison to the patent example, only the quantities of raw materials used are increased six-fold.

In a multi-necked flask with stirrer, dropping funnel, reflux condenser and gas discharge pipe connected to it, 15.2 g (84 mmol) of 4-bromovaleric acid and

3.8 g (210 mmol) of water are introduced and heated to 40 ° C. At a temperature of 40 to 45 ° C 19.0 g (138 mmol) of phosphorus trichloride are added dropwise with stirring within 20 minutes. After the addition has ended, the reaction mixture is heated to 130 ° C. for 15 minutes and to 120 ° C. for 2.75 hours. Reflux initially occurs from an internal temperature of 110 ° C. The mixture is then allowed to cool to room temperature and a solution of 8.9 g (138 mmol) of 86.7% potassium hydroxide and 10.8 g is added dropwise with cooling at 25 to 30 ° C. in the course of 15 minutes (85.6 mol) sodium sulfite in 90 g water. The reaction mixture is alkaline immediately after the solution is added dropwise. After heating to 95-100 ° C., the pH drops to approximately 6. The mixture is heated to 100 ° C. with stirring for 19 hours. The solution obtained (129.9 g) has a final pH of 4.3.

The ^3, P-NMR spectrum (solvent D ₂ O) shows a triplet characteristic of the -CH ₂ -C (OH) (PO ₃ M ₂ ) ₂ group of achiral compounds at 19.0 ppm. This group contains 23.1% of the phosphorus. Together with other phosphonates of unknown structure, a total of 87.8% of the phosphorus is present in phosphonates. The majority of the phosphonates contained can be obtained from the

Do not assign structure. 8.9% of the phosphorus is present as phosphate of the formula (V), the chemical shift of which is 0.7 ppm.

Example 5

Calcium tolerance test

700 ml of demineralized water are placed in 1 -1 glass bottles and the inhibitor solution and 10 ml of a solution which contains 183.4 g of CaCl ₂ × 2H ₂ O / l are added with stirring. A neutralized solution with an active substance content of 10,000 mg / l is usually used as the inhibitor solution, so that an addition of 5, 10 or 20 ml corresponds to an inhibitor concentration of 50, 100 or 200 mg / l.

The pH of the solution is adjusted to 9.0 by adding sodium hydroxide solution or hydrochloric acid, and the volume is then made up to 1 liter. This solution contains 500 mg / 1

Ca ²⁺ .

The sealed bottles are stored in a forced-air drying cabinet at 75 ° C for 24 h. After cooling, the pH is measured (control) and - after stirring in any salts which may have precipitated for homogenization - the turbidity of the samples measured in a turbidity photometer according to EN 27027 in a 50 mm cuvette and given as FNU (formazin - nephelometry unit).

The higher the turbidity values, the more calcium inhibitor salt has separated out. Low turbidity values therefore correspond to a high calcium tolerance.

A high calcium tolerance is a prerequisite for an effective calcium carbonate inhibition in water with a high calcium concentration.

As Table 1 shows, the Ca tolerance of the substance according to the invention from Example 1 and of the substances from Comparative Examples 3 and 4 described by US Pat. No. 5,221,487 is significantly higher than that of HEDP. Somewhat better than HEDP, but significantly worse than the substance according to the invention from example 1, cuts off the sample which was produced from 3-bromopropionic acid in extension of the method proposed in US Pat. No. 5,221,487 to shorter carbon chain lengths (see comparative example 1 ).

In contrast to the other substances, the samples from comparative examples 1 and 3 are not stable under the experimental conditions of the Ca tolerance measurement. The pH value drops significantly during the measurement.

Table 1

Measurement of calcium tolerance using turbidity experiments

significant pH drop during storage over 24 h at 75 ° C

Example 6

Testing for stone-inhibiting effectiveness

Three different waters (see Examples 6a) to 6c)), which are oversaturated in calcium carbonate, are synthetically prepared from demineralized water by dissolving salts and adjusting the pH with sodium hydroxide solution or hydrochloric acid. In these waters, the deposition of solids during storage is examined depending on the added stone inhibitors of different structure and concentration.

Example 6a)

To test the stone-inhibiting effect, a synthetic tap water of the following composition is produced: 100 mg / 1 Ca ²⁺ and 12 mg / 1 Mg ²⁺ , corresponding to 3 mmol / 1 alkaline earth ions and a total hardness of 300 ppm CaCO ₃ or 17 ° d GH,

195 mg / 1 HCO ₃ ^" , corresponding to 3.2 mmol / 1 and a carbonate hardness of 9 ° d KH,

145 mg / 1 Na ⁺ , 197 mg / 1 SO ₄ ^{2 "} and 177 mg / 1 Cl ^" .

The total hardness (initial hardness) of this water is determined by titration with EDTA.

A small amount of the inhibitor is added to this water so that its concentration in the test solution, calculated as free inhibitor acid, is 2, 5, 10 or 25 ppm. The solution is adjusted to a pH of 11.0 by adding sodium hydroxide solution (c = 1 mol / 1) and stored in a closed glass bottle with the glass rod set in a drying cabinet at 60 ° C. for 24 h. After

Storage, the solution is visually examined for deposited crystals and filtered through a 0.45 μm membrane filter. The total residual hardness in the filtrate is determined by titration with EDTA. The "residual hardness in%" (RH [%]), listed in Tables 2 to 4, is calculated using the following formula:

a - b

RH [%] = x 100 c - b

a = residual hardness in the filtrate of the sample to be tested b = residual hardness in the filtrate of a blank sample without inhibitor c = initial hardness

The higher the RH [%] in the filtrate, the more effectively the CaCO ₃ precipitation is inhibited. The possible separation of scale, i.e. a coating that is stuck on the glass surfaces, is particularly serious and is noted in Tables 2 to 4 by an asterisk.

As Table 2 shows, the formation of scale from the simply concentrated synthetic water from an inhibitor concentration of 25 mg / 1 is only possible when using the substance according to the invention from Example 1 and the substances claimed by US Pat. No. 5,221,487 from Comparative Examples 3 and 4 reached. HEDP and the substance which was produced from 3-bromopropionic acid as an extension of the process proposed there to shorter carbon chain lengths (see comparative example 1) cannot prevent scale formation even at an inhibitor concentration of 25 mg / l.

At lower doses (<10 mg / 1 inhibitor), the substance according to the invention is able to stabilize a higher residual hardness than all other comparison substances.

Table 2

Residual hardening in simply concentrated synthetic water after 24 h at 60 ° C and pH 11

* = Deposition from scale

Example 6b)

In comparison to Example 6a), a synthetic water with double

Ion concentrations used. The inhibitor-containing test solution is adjusted to a pH of 9.0 by adding sodium hydroxide solution (c = 1 mol / 1) and stored at 80 ° C. for 24 hours. See Table 3 for results.

According to Table 3, the minimum inhibitor concentration which just prevents scale from being separated from double-concentrated synthetic water is 5 mg / l for the substance according to the invention from Example 1, and for the substances from the comparative examples claimed by US Pat. No. 5,221,487 3 and 4 at 10 mg / 1, in the case of the manufacturing process provided sample from comparative example 1 at 25 mg / 1 and at HEDP above 25 mg / 1. The substance according to the invention therefore already achieves the same effect as the substances described there at half the dosage.

Table 3

Residual hardness in double concentrated synthetic water after 24 h at 80 ° C and pH 9

* = Deposition from scale

Example 6c)

In comparison to Example 6a), a synthetic water with four times the ion concentration is used. The inhibitor-containing test solution is adjusted to a pH of 9.0 by adding sodium hydroxide solution (c = 1 mol / 1) and stored at 60 ° C. for 24 hours. See Table 4 for results.

Table 4

Residual hardness in four times concentrated synthetic water after 24 hours

60 ° C and pH 9

sc e ung of ca e, = c amm ung

According to Table 4, 4-fold concentrated synthetic water is stabilized to a clear solution at 60 ° C. and pH 9 only at a very high inhibitor concentration of at least 400 mg / l, and also only when the inhibitor according to the invention or the inhibitor according to Example 1 Comparative Example 4 are used. HEDP and the substances from comparative examples 1 and 3 result in this Dosage for sludge formation. The negative value for the percentage residual hardness in the 400 mg / 1 HEDP test is remarkable. A negative RH [%] value means that the total hardness after the end of the test with inhibitor (in this case 723 ppm CaCO ₃ ) is lower than in a comparative test without inhibitor (750 ppm CaCO ₃ ). In this experiment, HEDP has a precipitating effect on the calcium ions. This behavior is in agreement with the low calcium tolerance of HEDP (see Table 1).

Example 7

Testing for corrosion-inhibiting effectiveness

To test the corrosion-inhibiting effect, a synthetic cooling water is produced which has twice the ion concentrations in comparison to example 6a). An inhibitor concentration of 30 mg / l is established in 12 liters of this synthetic water by adding de-neutralized inhibitor. This solution is poured into a 12 liter container in which four steel tube rings made of carbon steel (St 37) degreased by pretreatment with acetone are moved through the solution at a speed of 0.6 m / s on a stirrer. During the entire test period, 0.4 l / h of fresh aqueous solution, which in contrast to the 12 liters of initial solution contains 20 mg / 1 inhibitor, are metered into the container, and the same volume flow of solution is drained off via an overflow. After 72 hours, the rings are removed and pickled with hydrochloric acid. The loss of mass of the rings is determined and related to the surface of the rings and the test time. From this, a removal type of 0.06 mm / a is calculated for the substance from Example 1, and a removal rate of 0.05 mm / a for HEDP. In a blind test without inhibitor, the removal rate is 0.17 mm / a.

Claims

claims

1. Compounds of the formula (I) and their salts,

where R ¹ and R ² independently of one another are hydrogen or methyl and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion.

2. Compounds according to claim 1, characterized in that in formula (I) R ¹ and R ^{2 are} hydrogen and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion.

3. Compounds according to claim 1, characterized in that in formula (I) R ^{1 is} methyl and R ^{2 is} hydrogen and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion.

4. Compounds according to claim 1, characterized in that in formula (I)

R ^{1 is} hydrogen and R ^{2 is} methyl and M ¹ to M ⁵ independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion.

5. Mixtures, characterized in that in addition to a compound of formula (I) according to claims 1 to 4, the following further components are contained: one or more sulfonic acids of formula (II) or their salts

one or more hydroxy acids of formula (III) or their salts

a phosphite of the formula (IV) = M'M ² HPO ₃

a phosphate of the formula (V) = M'M ² M ³ Pθ4

where R ¹ and R ² independently of one another are hydrogen or methyl, M ¹ to M ⁵ and M 'independently of one another represent a hydrogen, alkali, ammonium or an alkylated ammonium ion, Z represents a group of the formula -COOM ¹ or C (OH) (PO ₃ M ¹ M ² ) ₂ , n can take integer values from 1 to 5 and the mean value for n over all compounds of types (II) and (III) is between 1 and 2.

Mixtures according to claim 5, characterized in that at least 30% of the total phosphorus of the mixture is present in a compound of formula (I).

7. Mixtures according to claim 5, characterized in that at least 60% of the total phosphorus of the mixture is present in a compound of formula (I).

8. Mixtures according to claim 5, characterized in that a maximum of 15% of the total phosphorus of the mixture is present in a phosphate of the formula (V).

9. Mixtures according to claim 5, characterized in that the molar ratio of the compounds of formula (II) to compounds of formula (III) is at least 5 to 1.

10. Mixtures according to claim 5, characterized in that the molar ratio of the compounds of the formulas (II) and (III) with Z = -C (OH) (PO ₃ M ₂ ) ₂ to compounds of the formulas (II) and (III) with Z = COOM is at least 1 to 1.

1 1. Process for the preparation of the compounds according to claim 1 and the

Mixtures according to claim 5, characterized in that

a) 1 mol of sulfur dioxide with at least 1 mol of water, at least

1 mol of a monovalent base and with 0.9 to 2 mol of an unsaturated carboxylic acid or a carboxylic acid mixture are reacted, carboxylic acids of the formula

are used and R ¹ and R ^{2 are} independently hydrogen or methyl;

b) the reaction mixture from step a) is optionally treated with a strongly acidic cation exchanger in the H ⁺ form;

c) the reaction mixture from step b) is optionally dewatered; d) the reaction mixture from step a) or c) is reacted with a raw material containing P (III) under dehydrating conditions, the molar amount of phosphorus used being 1.6 to 2.4 mol, if appropriate in the presence of an amine salt;

e) the reaction mixture from step d) is hydrolyzed with the addition of a sufficient amount of water or aqueous hydrochloric acid;

f) the reaction mixture from step e) optionally for distillation

Undergoes removal and recovery of volatile components;

g) the reaction mixture from step e) or f) is optionally alkalized with alkali metal hydroxide solution, the amine is separated off and reused in step a) or d).

12. The method according to claim 11, characterized in that acrylic acid, methacrylic acid or crotonic acid is used as the carboxylic acid.

13. The method according to claim 11, characterized in that acrylic acid, crotonic acid or a mixture of the two is used as the carboxylic acid.

14. The method according to claim 11, characterized in that acrylic acid is used as carboxylic acid.

15. The method according to claim 11, characterized in that an alkali metal hydroxide or an aliphatic primary, secondary or tertiary amine is used as the base.

16. The method according to claim 11, characterized in that the molar amount of the base added in step a) is not greater than the sum of the molar amounts of sulfur dioxide and carboxylic acid combined.

17. The method according to claim 11, characterized in that in step d) as

P (III) -containing raw material phosphorus trichloride is used and the reaction mixture before the PCl ₃ addition contains 1 to 2.4 mol of water per mol of PC1 _{3 to be added} .

18. The method according to claim 11, characterized in that in step d) as

P (III) -containing raw material phosphorus trichloride is used and the reaction mixture before the PCl ₃ addition contains 1.4 to 1.8 mol of water per mol of PC1 _{3 to be added} .

19. The method according to claim 11, characterized in that step d) are carried out at a temperature of 40 to 180 ° C and step e) at a temperature of 70 to 120 ° C.

20. The method according to claim 11, characterized in that the process steps b) and c) are omitted by

a) in a first substep 1 mol of sulfur dioxide with 3 to 5.8 mol

Water and 1 mol of a tertiary aliphatic amine are reacted, in a second sub-step the product mixture obtained is reacted with 0.9 to 2 mol of the same amine and at least the same molar amount, but at most 2 mol of an unsaturated carboxylic acid or a carboxylic acid mixture, carboxylic acids of the formula

are used and R ¹ and R ^{2 are} independently hydrogen or methyl;

d) the reaction mixture from step a) is reacted with 1.6 to 2.4 mol of phosphorus trichloride;

e) the reaction mixture from step d) is hydrolyzed with the addition of 5.2 to 100 mol of water;

f) the reaction mixture from step e) optionally for distillation

Undergoes removal and recovery of volatile components;

g) the reaction mixture from step e) or f) is alkalized with alkali metal hydroxide solution, the tertiary aliphatic amine is separated and in

Step a) is used again.

21. The method according to claim 20, characterized in that acrylic acid, methacrylic acid or crotonic acid is used as the carboxylic acid.

22. The method according to claim 20, characterized in that acrylic acid, crotonic acid or a mixture of the two is used as the carboxylic acid.

23. The method according to claim 20, characterized in that acrylic acid is used as the carboxylic acid.

24. The method according to claim 20, characterized in that tributylamine is used as the base.

25. The method according to claim 20, characterized in that the first sub-step from process step a) is carried out at a temperature of 0 to 40 ° C, the second sub-step at a temperature of 40 to 100 ° C.

26. The method according to claim 20, characterized in that step d) are carried out at a temperature of 40 to 180 ° C and step e) at a temperature of 70 to 120 ° C.

27. The method according to claim 20, characterized in that process step d) are carried out at a temperature of 60 to 130 ° C and process step e) at a temperature of 90 to 110 ° C.

28. Agents for water treatment and for use in alkaline cleaners, characterized in that an l-hydroxy-3-sulfonoalkane-l, l-diphosphonic acid according to claim 1 or a phosphonate-containing mixture according to claim 5 in a total phosphonic acid concentration of 1 to 20% is included.

29. A method of water treatment, characterized in that an agent according to claim 28 is added to the water and in the one to be treated

Water sets a total phosphonic acid concentration of 1 ppm to 500 ppm.

30. A process for alkaline cleaning, characterized in that an agent according to claim 28 is added to the water and in the to be treated

Water sets a total phosphonic acid concentration of 1 ppm to 1000 ppm.

31. Use of l-hydroxy-3-sulfonoalkane-l, l-diphosphonic acids according to claim 1 or the phosphonate-containing mixtures according to claim 5 for

Inhibition of metal corrosion and scaling in cooling water systems, sea water evaporators, steam generating systems, gas washing systems, cooling and heating systems and pressurized water for secondary oil production.