WO1994022991A1

WO1994022991A1 - Use of polyasparaginic acid in chain lubricants for conveyor belts of bottle filling and washing installations

Info

Publication number: WO1994022991A1
Application number: PCT/EP1994/000953
Authority: WO
Inventors: Birgit Potthoff-Karl; Matthias Kroner; Gunnar Schornick
Original assignee: Basf Aktiengesellschaft
Priority date: 1993-04-06
Filing date: 1994-03-25
Publication date: 1994-10-13
Also published as: DE4311237A1

Abstract

Polyasparaginic acid and condensates of asparaginic acid containing up to 40 % by moles of other condensed aminoacids, as well as the alkaline and ammonium salts of said polyasparaginic acids, are used in chain lubricants for conveyor belts of bottle filling and washing installations. Also disclosed are chain lubricants based on mixtures of water, soap, surfactants, fatty acid, alkanolamines and 1 to 30 % by weight polyasparaginic acid, condensates of asparaginic acid containing up to 40 % by moles of other condensed aminoacids, and/or alkaline and ammonium salts of the polyasparaginic acids useful for conveyor belts of bottle filling and washing installations.

Description

Use of polyaspartic acid in chain lubricants for conveyor belts in bottle filling and cleaning systems

description

The invention relates to the use of condensates of aspartic acid in chain lubricants for conveyor belts of bottle filling and cleaning systems and chain lubricants which contain condensates of aspartic acid.

The thermal polymerization of aspartic acid with other amino acids such as glutamic acid at temperatures of 160 to 210 ° C. is known from US Pat. No. 3,052,655. The polycondensation can optionally be carried out in the presence of phosphoric acid, it being possible to use molar amounts of phosphoric acid on the amino acids used in the condensation.

From DE-A-20 32 470 the thermal polycondensation of aspartic acid under reduced pressure at temperatures from 170 to 200 ° C is known. The polycondensation can optionally be carried out in the presence of phosphoric acid. The reaction products of the polyaspartimides obtainable in this way with alkanolamines are used as blood plasma expanders. US Pat. No. 4,534,881 describes the inhibition of inorganic or biological calcium carbonate precipitates by polyaspartate, polyglutamate and copolycondensates with other amino acids. The polycondensates preferably have molecular weights from 3500 to 10,000. For example, they are used as scale inhibitors in seawater treatment plants or cooling circuits.

According to the teaching of DE-A-36 26 672, polyaspartic acid is formed by thermal polycondensation of maleic monoammonium salt at 120 to 150 ° C. The polyaspartate can prevent glass from becoming dull in dishwashers. The potassium, magnesium and calcium salts of polyaspartic acid can also be used as fertilizers.

From DE-A-22 53 190 it is known that polyaspartic acids modified with long-chain alkyl amines can be used as surfactants in detergents.

DE-A-40 23 463 discloses a process for the preparation of polyaspartic acid in two stages, in which aspartic acid is first treated with phosphoric acids at temperatures up to 250 ° C condensed under reduced pressure, then crushed the reaction mixture and post-condensed. The polycondensates are used to produce, by means of polymer-analogous reactions, for example plasma expanders or by reaction with amines, polyaspartic acid derivatives which are used in pharmaceutical and food-technical preparations, these polymers having to be film-forming.

The use of polyaspartic acid as a builder in detergent formulations is known from EP-A-0 454 126 and EP-A-0 511 037. According to the teaching of WO-A-92/15535, polyaspartic acids with molar masses of 1000 to 5000 are used as dispersants. Chain lubricants for the tapes of bottle filling and bottle cleaning systems usually consist of 15 mixtures of water, soap, surfactants, fatty acids, alkanolamines and complexing agents. However, the substances used in practice as complexing agents, the sodium salts of ethylenediaminetetraacetic acid (EDTA), are not biodegradable.

The object of the invention is to provide biodegradable complexing agents for chain lubricants.

The object is achieved according to the invention with the use of polyaspartic acid and condensates of aspartic acid, which contain up to 25 40 mol% of other amino acids, as well as the alkali and ammonium salts of polyaspartic acid and the named condensates in chain lubricants for conveyor belts for bottle filling and Cleaning systems.

The invention also relates to chain lubricants based on mixtures of water, soap, surfactants, fatty acids and alkanolamines for conveyor belts in bottle filling and cleaning systems. According to the invention, the mixtures contain 1 to 30% by weight of polyaspartic acid, condensates of aspartic acid which

Contain 35 to 40 mol% of other amino acids in condensed form and / or alkali and ammonium salts of polyaspartic acid and the named condensates.

L-, D- and DL-aspartic acid can be used as the starting material for the production of polyaspartic acid 40 and the reaction products containing condensed aspartic acid. DL-aspartic acid is technically easily accessible, for example by reacting ammonia with maleic acid or fumaric acid under pressure. L-aspartic acid can be produced, for example, by asymmetric addition of ammonia to fumaric acid catalyzed by 45 L-aspartase. Suitable microbes for the industrial bioconversion of fumaric acid into L-aspartic acid include mutated ones Strains of, for example, Pseudomonas, Brevibacterium flavum or lactoferum. The microorganisms can be immobilized on a solid phase in the catalyzed addition of ammonia to fumaric acid. The production of L-aspartic acid can thus flow economically and continuously in one

Reactor or tube are carried out, cf. Ullmann's Encyclopedia of Industrial Chemistry, 1985, volume A2, page 68. L-aspartic acid can also be produced, for example, by chemical or enzymatic hydrolysis of L-asparagine. L-asparagine is a by-product of sugar molasses and potato processing. L- and DL-aspartic acid are preferably used to produce the polycondensates. Biotechnologically produced L-aspartic acid is particularly preferably used as the starting material for the production of the polyaspartates.

In addition to the condensates which can be obtained by thermal condensation of aspartic acid alone, cocondensates of aspartic acid with up to 40 mol% of other α-amino acids can also be used as deposit inhibitors. Suitable other α-amino acids and their half-amides are, for example, asparagine, iso-asparagine, glutamic acid, glutamine, lysine, arginine, histidine, glycine, alanine, valine, leucine, isoleucine, 4-aminobutyric acid, 2-aminoisobutyric acid, hydroxyamino acids, such as serine , Threonine or N- (hydroxyethyl) glycine and imino acids such as proline, aromatic and heteroeyclic amino acids such as phenylalanine, tyrosine, anthranilic acid or tryptophan, and sulfur-containing amino acids such as cystine, cysteine and methionine. Also suitable as other amino acids for the preparation of the cocondensates are the aminodicarboxylic acids such as diaminobutyric acid or N-methylamino acids, for example sarcosine or N-methylalanine. All amino acids can be used in the L and D configuration or in the form of mixtures of L and D amino acids in any mixture ratio and as racemates. However, preference is given to using L-aspartic acid as the sole starting material for producing the thermal polyaspartic acid.

The aspartic acid is condensed by tempering the aspartic acid crystals at temperatures of 140 to 260 ° C., preferably at 190 to 240 ° C., for up to 50 hours. The tempering is preferably carried out in a vacuum or under an inert gas atmosphere. However, the condensation reaction can also be carried out under elevated pressure or in a gas stream, for example carbon dioxide, air, nitrogen or superheated steam. The times for the condensation depend on the chosen reaction conditions; they are generally between 10 minutes and 50 hours. For the technical production of the poly Condensates can be used, for example, a drying belt, a paddle dryer, a tumble dryer or a fluidized bed dryer. Low molecular weight polycondensates can also be produced in a pressure-tightly closed vessel by not or only partially removing the water formed during the condensation.

In the polycondensation of aspartic acid and the co-condensation of aspartic acid with other α-amino acids, one can also start from the salts of aspartic acid or the salts of the other amino acids if additional organic acids are used in the polycondensation. The condensation temperatures can then be reduced compared to the purely thermal polycondensation of aspartic acid. Another advantage is that practically non-colored polycondensates are obtained. When salts of aspartic acid and inorganic acids are used, the condensation temperatures are 120 to 260 ° C. and are preferably in the range from 140 to 220 ° C., while the reaction times are about 1 minute to 10 hours.

All hydrohalic acids can be used as inorganic acids. Hydrochloric acid is preferably used. The hydrohalic acids can be used in gaseous or liquid form. Concentrated aqueous solutions of hydrochloric acid are preferably used, in which aspartic acid is soluble to form aspartic acid hydrochloride. However, liquid or gaseous hydrogen chloride can also be used to produce the hydrochlorides. The aqueous solutions of the aspartic acid hydrochloride are evaporated to dryness and the residue is polycondensed by heating to temperatures in the range given above. For the continuous evaporation of the aqueous solutions of the hydrochlorides of aspartic acid, for example, a spray dryer or a spray whirl layer dryer can be used. The polycondensation of the hydrochlorides can take place directly after the evaporation or at a later point in time. Suitable apparatus for the condensation are all those devices in which solids can be heated to temperatures of up to 260 ° C. in a vacuum or in a gas stream. In the course of the polycondensation, the hydrogen chloride emerges again from the condensation product. The hydrogen chloride released can be recovered and reacted again with aspartic acid.

The polycondensation of aspartic acid or its co-condensation with the other possible acids can also be carried out with inorganic acids of phosphorus in various oxidation states. As inorganic acids of phosphorus sets phosphoric acid and polymeric anhydrides of phosphoric acid (polyphosphoric acids) are preferred. Technical, 75 to 85% aqueous ortho-phosphoric acid is preferably used as the phosphoric acid. However, 100% ortho-phosphoric acid or meta-phosphoric acid can also be used. Of the polymeric anhydrides of polyphosphoric acid, for example, diphosphoric acid (pyrophosphoric acid), triphosphoric acid and higher homologs are suitable. The polycondensation can also be carried out with an excess of phosphorus-containing acids. This measure can be of advantage in cases in which higher molecular weight polyaspartimides form very highly viscous solutions in phosphoric acids. In such cases, superstoichiometric amounts of phosphoric acid as solvents and diluents can reduce the viscosity of the resulting polymer solutions.

The reaction with the phosphoric acids takes place in such a way that aspartic acid and optionally other amino acids are slurried in phosphoric acid at 20 ° C. and heated to a temperature of about 100 ° C. in vacuo. The water that may be introduced with the phosphoric acid distills off, at the same time the aspartic acid dissolves in the phosphoric acid. A homogeneous melt of an aspartic acid phosphate is obtained which is thermally polycondensed by heating to temperatures in the range from 120 to 260 ° C., preferably in vacuo. As the polycondensation progresses, the viscosity of the reaction mixture increases. The increase in the molecular weight can be followed by the increase in the viscosity of the reaction mixture. The molecular weight of the polycondensates can be limited by premature termination of the polycondensation reaction, for example by introduction into water. If the polycondensation is carried out to the end, homogeneous, very highly viscous solutions of polyaspartimides in anhydrous phosphoric acid are obtained.

The polycondensation of aspartic acid and possibly the other amino acids in polyphosphoric acid takes place in an analogous manner. Polyphosphoric acids are formed by dissolving phosphorus pentoxide in phosphoric acid. For example, a slurry of crystalline aspartic acid in polyphosphoric acid is heated to a temperature of 120 to 250 ° C. The aspartic acid first goes into solution. This solution is then annealed, preferably in a vacuum. The aspartic acid is polycondensed. The polycondensation of aspartic acid can also be carried out in the presence of derivatives of phosphoric acid, for example phosphorus oxychloride, phosphorus oxybromide, phosphorus pentachloride and phosphorus pentoxide. Also suitable are phosphoric acids in which the phosphorus has a lower oxidation level than +5. This group of acids includes, for example, the phosphorous Acid, which, based on 1 mol of aspartic acid, is used in amounts of 0.05 to 0.3 mol in the polycondensation. However, phosphorous acid can also be used in combination with phosphoric acid or hydrochloric acid. For example, the condensation of aspartic acid with a mixture of 1 mol of phosphoric acid and 0.05 to 0.1 mol of phosphorous acid per 1 mol of aspartic acid has proven to be very advantageous. Mixtures of 1 mol of hydrochloric acid and 0.05 to 0.1 mol of phosphorous acid per 1 mol of aspartic acid can also be used in the polycondensation. In addition, derivatives of phosphorous acid are suitable as auxiliaries in the condensation in order to lower the temperature required for the condensation and to accelerate the reaction. In addition to the phosphorous acid, phosphorus trichloride, phosphorus tribromide, triethyl phosphite, diethyl chlorophosphite, ethyl dichlorophosphite or tetraethyl pyrophosphite can also be used in the condensation.

Another possibility is to condense aspartic acid in the presence of hypophosphorous acid. The hypophosphorous acid is usually used in the form of aqueous solutions. 0.05 to 0.5 mol of hypophosphorous acid is used per 1 mol of aspartic acid. The hypophosphorous acid is homogeneously distributed on the aspartic acid by dissolving the aspartic acid together with hypophosphorous acid in water and evaporating the solution. The hypophosphorous acid can also be used in combination with hydrochloric acid or phosphoric acid. For example, a mixture of 1 mol of phosphoric acid and 0.05 to 0.1 mol of hypophosphorous acid or a mixture of 1 mol of hydrochloric acid with 0.05 to 0.5 mol of hypophosphorous acid per 1 mol of aspartic acid is used in the condensate tion. The production of the condensates by elimination of water from crystalline L-aspartic acid at temperatures of 180 to 260 ° C. and the elimination of water from L-aspartic acid in phosphoric acid medium at 130 to 220 ° C. is particularly preferred.

Suitable other inorganic acids which are used in the polycondensation of aspartic acid are, for example, sulfuric acid, disulfuric acid, sulfur trioxide, sodium and potassium hydrogen sulfate.

During the thermal polycondensation of aspartic acid, the polycondensate is obtained in the form of the water-insoluble polyaspartic acid amides. The polyaspartimides are soluble in phosphoric acid and dimethylformamide. They have a 1% solution in dimethylformamide K values from 8 to 70, preferably 10 to 45. The polyaspartimides or the co-condensates of aspartic acid with the other amino acids can be added from the unreacted starting materials. can be cleaned, for example, by comminuting the condensation product and extracting it with 1 to 10 times the amount of water at temperatures from 0 to 100.degree. The unconverted acids are released. Polyaspartic acid imide or the cocondensates remain as an insoluble residue. Unreacted aspartic acid can easily be removed by extraction with 1N hydrochloric acid.

The unmodified polyaspartic acids are preferably obtained from the polyaspartimides by slurrying the polyaspartimides in water and hydrolyzing and neutralizing them at temperatures in the range from 40 to 90 ° C. with the addition of base. These reactions can of course also be carried out at temperatures which are below and above the range given above. Suitable bases are, for example, sodium hydroxide solution, potassium hydroxide solution, sodium carbonate, potassium carbonate, ammonia and amines, such as trimethylamine, diethylamine, ethanolamine, diethanolamine, triethanolamine and morpholine. The neutralization can also be carried out using alkaline earth metal bases, e.g. Calcium hydroxide or barium hydroxide. The treatment of the polyaspartimides is preferably carried out at pH values from 8 to 10. Hydrolysis and neutralization can be accelerated by the action of ultrasound on the reaction partners. In the treatment with bases, partially or completely neutralized polyaspartic acids or condensates, which contain at least 60 mol% aspartic acid and up to 40 mol% of other amino acids condensed, are obtained in the form of the alkali metal or ammonium salts. The polymers have K values (determined according to H. Fikentscher in a 1% strength aqueous solution at pH 7 and 25 ° C. on the sodium salt) of 5 to 150 and preferably 10 to 100.

The polyaspartic acids and the condensates of aspartic acid with other amino acids are biodegradable according to OECD Guidelines for testing of Chemicals (1981), 302 B (modified Zahn-Wellens test). They are also degradable according to the decrease in dissolved oxygen in the closed bottle test.

Chain lubricants are usually used to lubricate the belts of machines on which bottles are transported, which are filled or cleaned. The composition of chain lubricants can only be given as an example because it is specially adapted to the conditions of the company in which they are used. The chain lubricants consist, for example, of mixtures which contain water, soap, surfactants, fatty acids, alkanolamines and complexing agents. Suitable fatty acids are, for example, -C ₂ to C ₂₂ carboxylic acids which are either aliphatic saturated or one or more contain ethylenically unsaturated double bonds in the molecule. Oleic acid is preferably used.

All conventional anionic or nonionic surfactants and mixtures of these surfactants can be used as surfactants. Suitable surfactants are, for example, alkyl sulfates, alkyl sulfonates, fatty alcohol alkoxylates, oxo alcohol alkoxylates, alkyl polyglucosides and fatty amine alkoxylates and fatty acid / protein condensates. Products of this type are commercially available.

Another essential component in chain lubricants are amine, potassium or sodium soaps, e.g. Potassium palmitate, sodium palmitate, potassium stearate, sodium stearate.

The chain lubricants also usually contain alkanolamines, such as monoethanolamine, diethanolamine, triethanolamine, morpholine or morpholm-N-oxide, or else mixtures, in particular mixtures of monoethanolamine and triethanolamine.

Another essential component of chain lubricants are complexing agents. According to the invention, polyaspartic acid and condensates of aspartic acid, which contain up to 40 mol% of other amino acids in condensed form, and the alkali and ammonium salts of these polymers are used as complexing agents. Condensates of aspartic acid which can be prepared in particular in the presence of phosphoric acid are biodegradable. Polyaspartic acid is preferably used as the complexing agent, which is obtainable by splitting off water from crystalline L-aspartic acid at temperatures of 180 to 260 ° C., or such condensates of aspartic acid are used which are split off from L-aspartic acid in a phosphoric acid medium at temperatures of 120 are available up to 250 ° C.

The chain lubricants contain water in all cases. These are clear solutions which result in clear solutions when diluted with hard water. The chain lubricants composed according to the invention can have, for example, the following composition:

5 - 30 parts by weight of polyaspartic acid or condensates

Aspartic acid with other amino acids 5 - 10 parts by weight of a Cχ ₃ / Ci ₅ -oxoalcohol ethoxylate with one

Degree of ethoxylation of about 10 5 - 10 parts by weight of a C-. / Ci ₅ -oxo alcohol ethoxylates with a degree of ethoxylation of about 8 to 5 parts by weight of a commercially available alkyl carboxylic acid

Mixture as solution broker up to 15 parts by weight of triethanolamine up to 5 parts by weight of monoethanolamine 15 to 20 parts by weight of oleic acid 15 to 30 parts by weight of water.

The pH of the chain lubricants is due to the content of at least 8. The alkanolamines Kettengleit- ^'described above medium is used for the application by adding water in a weight ratio of for example 1: 500 diluted further advertising the order required in the for the application Concentration.

The chain lubricants described above may optionally contain further additives, e.g. Corrosion inhibitors.

The proportion of polyaspartic acid or condensates of aspartic acid in the chain lubricant prevents the precipitation of poorly soluble calcium salts of oleic acid or the soaps contained in the chain lubricants.

The K values of the neutralized polycondensates were determined according to H. Fikentscher, Cellulosechemie, Vol. 13, 58 to 64 and 71 to 74 (1932) in aqueous solution at a temperature of 25 ° C and a concentration of 1% by weight pH 7 determined on the sodium salt of polyaspartic acids. The K values of the polyaspartimides were determined in 1% strength solution in dimethylformamide (DMF) at 25 ° C. The percentages in the examples mean% by weight.

example

Polyaspartic acid 1

By condensing L-aspartic acid in the presence of phosphoric acid in a molar ratio of 1: 1, polyaspartimide is obtained within 1.5 hours at a temperature of 150 ° C, which - after removal of phosphoric acid by washing with water - becomes a treatment with sodium hydroxide solution 40% aqueous solution is processed. The polyaspartic acid had a K value of 38.7 (determined at 25 ° C. and a concentration of 1% by weight at pH 7 on the sodium salt of polyaspartic acid).

A chain lubricant for conveyor belts for bottles is produced, for example, by mixing the following components:

30 parts by weight of a 40% aqueous solution of polyaspartic acid 1 20 parts by weight of triethanolamine 20 parts by weight of oleic acid 5 parts by weight of a C ₃ / Ci ₅ oxo alcohol ethoxylate with a

Degree of ethoxylation of approx. 2 - 10

3 parts by weight of a commercially available alkyl carboxylic acid mixture and

22 parts by weight of water

Samples of the mixture described above are then diluted with drinking water of 30 ° d hardness in a ratio of 1: 100, 1: 200 and 1: 300. The 3 dilutions are then examined by nephelometric turbidity measurement. The values obtained are given in the table.

Comparative Examples 1 and 2

In the formulation given in the example, polyaspartic acid 1 is replaced by the same amount of EDTA or NTA. 3 dilutions of this chain lubricant are then prepared and examined nephelometrically. The values obtained are given in the following table.

table

Results of the nephelometric turbidity measurement in [NTU units] when diluted

As can be seen from the table, polyaspartic acid has a better effect than EDTA and has the advantage over this complexing agent that it is biodegradable and toxicologically harmless.

Claims

1. Use of polyaspartic acid and condensates of aspartic acid, which contain up to 40 mol% of other amino acids condensed, as well as the alkali and ammonium salts of polyaspartic acid and the condensates mentioned in in ^: chain lubricants for conveyor belts in bottle filling and cleaning systems.

2. Use according to claim 1, characterized in that condensates are used which are obtained by elimination of water from crystalline L-aspartic acid at temperatures of 180 to 260 ° C.

3. Use according to claim 1, characterized in that condensates are used which are obtained by elimination of water from L-Aspara¬ ginsäure in phosphoric acid medium at 120 to 250 ° C.

4. Chain lubricant based on mixtures of water, soap, surfactants, fatty acids and alkanolamines for conveyor belts in bottle filling and cleaning systems, characterized in that the mixtures contain 1 to 30% by weight of polyaspartic acid, condensates of aspartic acid which up to

Contain 40 mol% of other amino acids condensed, and / or alkali and ammonium salts of polyaspartic acid and the condensates mentioned.