MACROCYCLIC ORGANIC POLYPHOSPHONATES

Abstract: Macrocyclic organic polyphosphonates belonging to the class of macrocyclic poly(methylene phosphonic) polyamines having general formula (I), in which n is an integer of from 2 to 5 and m is an integer of from 3 to 7, Me represents an element selected from hydrogen, an ammonium group, an alkali metal or an alkaline earth metal and x represents the valency of the element Me. These products find application for the stabilisation of aqueous solutions of hydrogen peroxide.

Description: Macrocyclic organic polyphosphonates. The present invention relates to organic polyphosphonates and particularly to macrocyclic organic polyphosphonates, a process for the preparation of these compounds, and stabilised aqueous solutions of hydrogen peroxide. The process for stabilising aqueous solutions of hydrogen peroxide using such stabilisers also comes within the scope of the invention. It is already well known particularly through the patent US-A-4001212 (E I Dupont de Nemours and Company) how to synthesise macrocyclic polyamines containing 3 to 7 atoms of nitrogen. The purpose of the invention is to provide compounds derived from macrocyclic polyamine organic polyphosphonates having particular properties, thereby rendering them particularly suitable for certain purposes, and especially for stabilising peroxygen compounds. To this end, the inve relates to macrocyclic organic polyphosphonates belonging to the class of macrocyclic poly (methylene phosphonic acid) polyamines having the following general formula 1: CH PO-jMe 2/x in which n is an integer of from 2 to 5 which can remain the same or vary within the same molecule, m is an integer of from 3 to 7 Me represents an- element selected from hydrogen, an ammonium group, an alkali metal or an alkaline earth metal and x represents the valency of the element Me. The polyphosphonates according to formula 1 have proved to have a good capacity for stabilising hydrogen peroxide. To this end, polyphosphonates in accordance with formula 1 which have proved to be particularly advantageous are those in which the element Me is chosen from alkali metals or alkaline earth metals. Alkali metals are preferred, and - most conveniently sodium. The macrocyclic poly(methylene phosphonic) polyamines according to formula 1 can be obtained by reaction between macrocyclic polyamines, formaldehyde and phosphorous acid: for example, according to the reaction scheme (A) below:- NH-(CH 2 ) n ,-- * fc5rf++ mm HHCCHHOO ++ m H3PO3 + m H 2° Hexaazacyclo-octadecane (n=2, m=6), tetraazacyclo- hexadecane (n=3, m=4) and tetrazacyclodecane (n=2, 3 alternately, m=4) can be mentioned as examples of macrocyclic polyamines which are particularly convenient for the preparation of macrocyclic polyphosphonates according to reaction scheme (A). The operating conditions under which the catalytic synthesis of the macrocyclic polyphosphonates from the corresponding macrocyclic polyamine according to formula 1 is carried out are those which are well known for polyphosphonate preparation generally, such as described by Moedritzer and Irani; Journal of Organic Chemistry, 1966, 31, 1603-1607 and can vary widely depending on the nature of the polyphosphonate whose preparation is desired. The synthesis is carried out in a reaction mixture containing strong acid, which is typically mineral acid catalyst, and especially is sulphuric acid or hydrochloric acid. For convenience in practice, a small excess such as up to 100% above the stoichiometric amounts of formaldehyde and phosphorous acid are preferred. Reaction is often carried out at or within 10°C below reflux conditions, typically for 1 to 6 hours. The resultant product is in the acid form and can be appropriately neutralised with suitable alkali earth bases or ammonia to produce the corresponding salts. In a particularly important aspect, the present inventio relates to an aqueous solution of hydrogen peroxide containi an effective amount of a stabiliser selected from macrocycli organic polyphosphonates having the general formula 1: CH 2 P0 3 Me 2/χ where n is a whole number between 2 and 5 and m is also a whole number between 3 and 7 Me represents an element selected from hydrogen, the ammonium group, alkali metals and alkaline earth metals x means the valency of the element Me. Aqueous solution of hydrogen peroxide means any aqueous solution of hydrogen peroxide whose concentration by weight is between 0.1 and 99g H 2 0 100g of solution and preferablybetween 0.5 and 95g H 2 O 2 /100g of solution. Advantageously, this solution can be a commercial solution of hydrogen peroxide with a concentration by weight of between 25 and 70g H O /100g of solution, or more dilute solutions sold for some purposes containing from 2.5 to 12.5g H 2 O 2 /100g solution. The most highly desirable macrocyclic organic polyposphonate content of the aqueous solution of hydrogen peroxide according to the invention depends on various parameters, including, particularly, the concentration of the hydrogen peroxide solution, its pH and the nature of the polyphosphonate selected, particularly its parameters n and m and the element Me, and also the nature of the end-use of the solution. A further factor influencing the stabiliser concentration, to some extent interrelated to the end use, comprises the extent and type of contaminants likely to be encountered by. the aqueous hydrogen peroxide solution, and particularly transition metal ions such as iron or copper. As a general rule, the higher the level of anticipated contamination, especially of transition metals, the higher the preferred content of stabilisers according to the present invention. In practice, it is generally desirable that the aqueous solution of hydrogen peroxide contain at least 0.5mg macrocyclic organic polyphosphonate or salt thereof per kg of solution, and preferably not more than 1500mg. The preferred contents are between 1 and 1000mg and amount chosen will usually take into account the above-identified parameters and factors. The invention has equal applicability to solutions of hydrogen peroxide which are acid, neutral or basic, such as from pHO to pH14. In particular, it finds an advantageous application for all acid solutions whose apparent pH is between 0 and 5, and the aqueous solutions used for the electronics industry, which have to be very pure can be highlighted. Examples of solutions suitable for stabilisation in accordance with the instant invention, are the solutions of hydrogen peroxide used for cleaning optical glass, particularly contact lenses, solutions of H 2 0 2 for hydrometallurgy, particularly the extraction of metals by leaching of ores or in the selective recovery of metals, H 2 0 2 solutions for engraving, pickling and polishing metals (for example liquors for the chemical polishing of copper, such as those described in patent application FR-A-87.13407 (Solvay and Co), H 0 2 solutions used for the protection of the environment, such as those used for detoxifying liquid or gaseous effluent and those used for the purification or disinfection of water, solutions of H 2 0 used in the food industry and, in particular those used for the disinfection of packaging and containers. According to another and advantageous method of employing the invention, the aqueous solution of hydrogen peroxide can be an aqueous bleaching liquor containing hydrogen peroxide in a concentration of between 0.5 and 50g H O 2 /100g of solution. Examples of such bleaching liquors, which are basic in nature, are the washing or bleaching liquors containing hydrogen peroxide for textile materials and the bleaching liquors containing hydrogen peroxide for pulps. In the methods for bleaching pulps using aqueous solutions of hydrogen peroxide, it can sometimes prove advantageous to pretreat the pulp to be bleached with an amino polycarboxylic acid of the type of those used in accordance with the invention or one of its salts such as those defined above, before carrying out the bleaching treatment with hydrogen peroxide. This latter method is particularly advantageous if the pulp to be bleached belong to the class of high yield pulps. The invention also relates to a process for stabilisin a peroxygen compound in which the compound is brought into contact with an effective amount of a stabiliser containing one or more phosphonate groups, characterised in that the stabiliser belongs to the class of macrocyclic poly ( ethylene phosphonic) organic polyphosphonates having the following general formula 1: where n is a whole number between 2 and 5 and m is also a whole number between 3 and 7 Me represents an element selected from hydrogen, the ammonium group, alkali metals and alkaline earth metals x means the valency of the element Me. The term peroxygen compound indicates herein a compound containing essentially the part structure -0-0- . The stabilising process' is particulary suitable for stabilising solutions of peroxygen compounds, such as an aqueous solution of hydrogen peroxide, by directly incorporating th stabiliser in the solution. For stabilisation of solid peroxygen compounds, the stabiliser is typically applied to the surface of the peroxygen compound, often in solution an remains on the surface or impregnates into the solid. Alternatively, the stabiliser can be present during the crystallisation of the peroxygen compound and thereby incorporated throughout the solid during manufacture. The invention has the advantage of providing aqueous solutions of hydrogen peroxide whose stability is improved with regard to decomposition brought about by the cations o heavy metals and transition metals in comparison with the known and commercially available organic stabilisers based upon organic -phosphonates. The non-limiting examples that follow are given with a view to illustrating the invention. Those not in accordance with the invention bear the suffix R. Example 1 This Example illustrates the preparation of the macrocyclic polyphosphonates according to the invention. The products were obtained in the following manner by mixing 2g hexacyclenetrisulphate (product made by EGA-Chemie) 3ml concentrated H 2 S0 (95 to 97%) 2ml distilled water and in a 25 cirr glass flask. The flask, fitted with a reflux condenser, was placed a thermostat and heated to 120°C. 2ml of an aqueous solution of formaldehyde containing 37% by weight formaldehyde was then added drop wise in a continuous manner over a period of one hour. The reaction mixture was kept at 120°C for two hours and then permitted to cool to ambient temperature. The final product was a yellow liquid. The NMR analysis of thi liquid shows that 82% of the phosphorus is in the form of methylene phosphonate. The product obtained is 1,4,7,10,13,16-Hexaazacyclo-octadecane hexa (methylene phosphonic) acid, also known as hexacyclenemethylenephosphonate or HCMP. Examples 2R to 7. Passivation of the equipment The equipment used in all the Examples that follow was subjected to a passivation treatment beforehand with a view to eliminating the deleterious, but non-quantifiable effect of the impurities adsorbed on the surface in contact with the stabilised solutions of hydrogen peroxide used. By so doing, it became possible to compare results to determine the effect of changes in which stabiliser that was present with confidence that the effect of euipment on the results had been virtually eliminated. To this end, all the glassware likely to be brought into contact with H 2 0 2 was immersed in an aqueous solution of 65% by weight HN0 3 and the whole assembly was kept at 75°C for two days. Stability tests 20.6ml of an aqueous solution of 85% by weight H 2 0 2 wa diluted into 29.4ml twice distilled water in a 100ml beaker passivated as described above, and 1ml of a contaminating solution containing, per litre, 0.540g FeCl 3 6H 2 0, 0.068g CuCl 2 .2H 0 and 3ml 1N HC1 was added. 1ml of aqueous solution of stabiliser containing 2.4 mmole/1 stabiliser to be tested was then added. After mixing, a test mixture wit a concentration of 40.2g H 2 O 2 /100g solution and containing 2.28 ppm metals and a stabiliser in a stabiliserrmetals molar ratio equal to 1.0 was thus obtained. The pH of the final mixture was then adjusted to 2.5 using a small quantity of HCl or concentrated NaOH, as necessary. The effect of HCMP as stabiliser in accordance with th invention was compared on the one hand, with no stabiliser and with a certain number of commercially available polyphosphonate stabilisers produced by Monsanto and sold under the br " and- name Dequest that are not in accordance wit the invention. These various stabilisers were designated by the following abbreviations: D2006 Na aminotrimethylenephosphonate D2016 Na 1-hydroxyethylidene 1 ,1-diphosphonate D2046 Na ethylenediamenetetra (methylenephosphonate) D2056 Na hexamethylenediamenetetra (methylenephosphonate) D2066 Na diethylenetriaminepenta (methylenephosphonate) A 25ml sample of the test mixture was then removed and introduced into a 50ml test tube with a ground glass neck. After the ground glass of the tube had been greased with silicone grease, the tube was assembled with a water manometer. The test tube and the manometer together were then immersed in a thermostat adjusted to 40°C for one hour in order to bring the temperature of the whole assembly into equilibrium. The initial level was then measured with the manometer and the measurement was repeated after a residence time of 1 hour at 40°C. The difference in the water levels measured with the manometer between the end and the beginning of the test was measured for each sample. This difference represents the volume of oxygen liberated by the solution of hydrogen peroxide during the duration (one hour) of the test. The volume of gaseous oxygen obtained after one hour when each of the various stabilisers was present in the test solution was measured and compared with the amount measured when no stabiliser was employed. This comparison n is expressed m Table 1 below as "proportion 0 liberated" . The proportion of 0 2 liberated varies inversely wirth the effectiveness of the stabiliser. It will be observed that Example 7 with the stabiliser HCMP which is in accordance with the invention gives the lowest measurement of all the stabilisers tested, thereby demonstrating that HCMP is more effective than all the commercially available stabilisers at stabilising aqueous solutions of hydrogen peroxide under otherwise identical test conditions. Example 8R to 10 With a view to increasing the accuracy of the test for the three best stabilisers in the foregoing test series, each of which restricted the proportion of oxygen liberated to less than 5% in comparison with the result obtained with the unstabilised solution, the stability test described in Examples 1R to 7 was repeated but incorporating the metals Fe/Cu, at 15 times higher concentration than in the previous test, the equimolar ratio between the metals and stabiliser still being retained. The results of the measurements of the oxygen liberated after one hour are shown in Table 2 below on the same comparative basis as before Table 2 Ex. No. Stabiliser reference Proportion 0 2 liberated, % 8R D2046 23.8 9R D2066 2.20 10 HCMP 0.25 These results confirm that the use of an HCMP stabiliser according to the invention achieves stabilisation of the aqueous solutions of hydrogen peroxide which is considerably more effective than that obtained using the two best commercially available stabilisers. Example 11 This Example illustrates the preparation of a second macrocyclic polyphosphonate according to formula 1, and specifically a derivative of cyclame. In this Example, cyclame (2.0g, 0.01m) was mixed with phosphorous acid (3.28g, 0.04m), demineralised water (10mls), hydrochloric acid (10mls, 36% w/w solution) in a 25ml glass flask fitted with a reflux condenser. The mixture was heated to reflux temperature about 107°C, and formaldehyde (6.01mls, 37% w/w solution, 0.08m) introduced gradually over a period of an hour whilst maintaining reflux conditions, which were subsequently maintained for a further hour. The product solution was permitted to cool to ambient and a white solid cyclame tetra (methylene phosphonic acid) was recovered in a yield of 4.13g, 72% of theoretical. Examples 12R and 13 In these Examples, the effectiveness of the invention stabiliser was compared with that from a commercially available organic phosphonic acid stabiliser under otherwise identical conditions. In each trial , an aqueous solution of 85% by weight H 2 0 2 was diluted with twice distilled water to form an aqueous solution of 70% byweight H 2 0 2 in a 100ml beaker pasεivated in the manner described above. A contaminating solution containing FeCl3.6H 2 0 was then added in order to obtain a concentration therein of 3.45.10 "* ^g Fe^ + /litre and 7.85.10 ~ Cu + g/1. 1000mg of stabiliser used per kg of aqueous solution of 70% by weight H 2 0 2 were then added. The solution was then diluted with its own volume of twice distilled water, and had a pH of 2.42. The stabilisers tested were 1,5,8,12- tetraazacyclotetradecanetetra (methylene phosphonic) acid, cyclame methylene phosphonate (CMP) produced in accordance with Example 11 of the invention, in Example 13, and a stabiliser D2010 not in accordance with the invention in Example 12R which was the fully acid form of D2016 previously mentioned herein. The volume of oxygen liberated over a period of three hours at 40°C was measured by the same type of apparatus as described for Examples 2R to 10, and used to calculate a gassing rate for each Example. These were 0.027mls 0 2 /min in Example 12R and 0.009mls 0 2 /min in Example 13. From the results it will be observed that the cyclame methylene phosphonate (CMP) achieved a reduction in the rate decomposition of hydrogen peroxide to one third that attained by the commercially available reference phosphonate stabiliser, showing it to be a much superior staibiliser and this demonstration was achieved despite the fact that the test is biassed in favourd of lower weight stabilisers such as D2010 (mol wt 212 compared with 612 for CMP) because it uses a constant weight of stabiliser. Example 14 In this Example, a long term storage trial was conducted of a concentrated aqueous solution of hydrogen peroxide containing as stabiliser a macrocyclic polyphosphonate produced by the process described in Example 1. Hydrogen peroxide solution, 85% w/w was diluted with twice distilled water to 70% w/w concentration in a 500 ml erlenmeyer flask, dosed with 200 ppm HCMP, calculated as the active material, and stored at laboratory ambient temperature. The residual concentration of hydrogen peroxide was measured by the standard iodide test after 6 months storage, and was found still to be 70% w/w, which indicates that the stabiliser is remarkably effective. In addition, the degradation of the phosphonate itself was monitored by a technique in which the phosphorous content of two samples of the aqueous 70% w/w solution were compared. The first sample was tested straightaway and the second sample after it had been passed through active carbon in order to retain the organic phosphonates. The difference between the two results is therefore an indication of the residual phosphonate content. The difference between the two samples at the start of the trial was 85% of the HCMP, and after respectively 3.5 and 6 months storage, the difference was still respectively 72% and 71%. Example 15 and Comparisons 16R to 21R In this Example and comparisons, solutions of hydrogen peroxide, works 70% w/w concentration, each containing a different stabiliser, were made up in passivated beakers. The concentration of stabiliser was always 100 ppm and the pH of the solution was adjusted to an initial pH of 1.0. A 50 ml sample of each-solution was introduced into a 50 ml cylindrical vessel fitted with a silicone greased ground joint to a manometer. The solution was maintained under the control of a thermostat at 70°C in a bath, 35 minutes being allowed for the solution to reach homogeneity. The volumes of gas, oxygen, generated in solution during in 4 hour period of the test were measured by the manometer, and expressed as a percentage of a blank trial. The results are summarised in Table 3 below. DTPA is diethylenetriamine- pentaacetic acid. The products Ionol and PHBN are known to trap radicals, PHBN being phenyl N-tertiary butyl nitrone. From the results given in Table 3, it can be seen that the invention stabiliser was easily the most efficient stabiliser.

Claims: CLAIMS 1. Macrocyclic organic polyphosphonates belonging to the class of macrocyclic poly (methylene phosphonic) polyamines, characterised in that they comply with the following general formula 1: ' - in which n is an integer of from 2 to 5 and m is an integer of from 3 to 7 Me represents an element selected from hydrogen, an ammonium group, an alkali metal or an alkaline earth metal and x represents the valency of the element Me. 2. An aqueous solution of hydrogen peroxide containing an effective amount as a stabiliser of a macrocyclic poly- (methylene phosphonic acid) polyamine according to formula 1 CH 2 P0 3 Me 2/χ in which n is an integer of from 2 to 5 and m is an integer of from 3 to 7 Me represents an element selected from hydrogen, an ammonium group, an alkali metal or an alkaline earth metal and x represents the valency of the element Me. 3. A product or composition according to claim 1 or 2, characterised in that n in formula 1 equals 2 or 3. 4. A product or composition according to claim 3 characterised in that n in formula 1 is selected from 2 and 3 in a regular pattern around the macrocycle. 5. A product or composition acco ' rding to claim 4 characterised in that n informula 1 is alternately 2 and 3 around the macrocycle and m equals 4. 6. A product or composition according to claim 3 characterised in that n in formula 1 always equals 2. 7. A product or composition according to claim 6 characterised in that m in formula 1 equals 6. 8. A product or composition according to any preceding clai characterised in that Me in formula 1 represents hydrogen or sodium. 9. A composition according to any of claims 2 to 8 characterised in that it is a commercial solution with a concentration by weight of between 0.5 and 95% hydrogen peroxide. 10. A composition according to any of claims 2 to 8 characterised in that it is a washing or bleaching liquor for textiles. 11. A composition according to any of claims 2 to 8 characterised in that it is a bleaching liquor for pulp. 12. A composition according to any of claims 2 to 8 characterised in that it can be used in the electronics industry. 13. A process for the stabilisation of a peroxygen compound in which the compound is brought into contact with an effective amount of a stabiliser therefor which contains one or more phosphonate groups, characterised in that the stabiliser comprises an effective amount of macrocyclic poly (methylene phosphonic acid) polyamine according to formula 1 and as described in any one of claims 1 or 3 to 8. 14. A process for the preparation of a macrocyclic organic polyphosphonate characterised in that a macrocyclic polyamine of formula in which n is an integer of from 2 to 5 and m is an integer of from 3 to 7 is contacted at elevated temperature with formaldehyde and phosphorous acid in a strong acid reaction medium thereby producing methylene phosphonic acid derivatives of the macrocyclic polyamine. 15. A macrocyclic polyamine N substituted by a methylene phosphonic acid group or salt thereof produced by a process according to claim 14.

Inventors: CHARLOT MICHEL, FEASEY NEIL DAVID, FERGUSON PAUL ANDREW, MORRIS GARETH WILMOT, VAN HEMELRIJK DIRK, CHARLOT, MICHEL, FEASEY, NEIL, DAVID, FERGUSON, PAUL, ANDREW, MORRIS, GARETH, WILMOT, VAN HEMELRIJK, DIRK
Applicants: INTEROX CHEMICALS LTD, INTEROX CHEMICALS LIMITED
Application year: 1989
Main classification: C07F9
IPC codes: C01B15, C07F9