GB2164929A - Liquid triazone fertilizer composition - Google Patents

Abstract

A liquid fertilizer composition comprises an aqueous solution of one or more substantially water soluble triazone compounds, one or more urea compounds, the triazone compound:urea compound weight ratio being 0.48:1 or more, and contains not more than the indicated amounts (dry weight basis) of the following: methylene diurea compounds 3% monomethylol urea compounds 7% hexamethylenetetramine compounds 2%, the triazone compound:methylene diurea compound weight ratio being 6:1 or more. The composition is prepared by (a) reacting in aqueous solution a urea, an aldehyde and ammonia or a primary amine; (b) thereafter further reacting in a first heating stage at a temperature between 80 DEG C-95 DEG C whilst adding aldehyde, urea or amine (or ammonia) to maintain the ratios of ingredients, and in a second stage at 80-95 DEG C to give a final reaction product having a triazone compound:unreacted urea compound weight ratio of at least 0.48.

Description

SPECIFICATION Liquid triazone fertilizer composition This invention relates to a novel liquid fertilizer and a method of making it. In particular it relates to a liquid triazone fertiliser composition.

The method of the invention may be said to relate to the preparation of a urea/aldehyde condensate. Prior methods of making fertilizers by apparently somewhat similar or related methods result in products exhibiting low or poor stability which decompose and/or convert to crystalline compounds or products that precipitate out thereby destroying their utility for use as liquid fertilizers, especially for foliar use. Solid fertilizers of the triazone or related types of waterinsoluble nature are not capable of releasing nitrogen to the roots so rapidly and thus are generally not economically or commercially feasible or practical.

Moreover, it has been found that by current technology, it is impossible to separate individual triazone compounds from mixtures thereof in water-containing reaction product mixtures thereof, and until procedures utilized by the present inventor, it has heretofore not been readily possible to ascertain exact structures and formulae of aqueous reaction products of processes related to or somewhat similar to the present method. Likewise until research by the present inventor, it heretofore had not been recognized or known what factors and/or constituents of a reaction product of a urea/aldehyde condensation reaction contribute to major instability of the watersolubility thereof, not has it been recognised what factor(s) in such a method control stability and/or yield of the final product(s) thereof.

While there is no certainty that somewhat similar or related processes to that of the present invention have resulted in the production of any triazone products as a part of the product mixture in water solution, nor that if any were so produced-the amount of triazone therein was present in any appreciable or significant amount, or for how long triazone compounds would be present prior to decomposition thereof or prior to the mixture (reaction product) becoming worthless as regards utility as a liquid fertilizer, especially a foliar fertiliser, because of crystallization and precipitation of constituents thereof, the closest apparently related method to that of the present invention appears to be the Justice et al United States Patent 3,462,256 issued on 19th August 1969.U.S. 3462256 is directed to and claims a process utilizing different process parameters and different mole ratio parameters for reactants, failing to recognize the presence (if any) of triazones and the importance thereof as a liquid fertilizer.

It would be desirable to provide a liquid fertilizer composition suitable for foliar application and soil application devoid of potential burning of foliage and/or soil, and to provide a liquid fertilizer composition suitable for situations requiring slow-release nitrogen sources.

The invention comprises three aspects, namely a liquid fertilizer of novel composition, a novel method of producing fertilizer compositions, and a novel method of fertilizer application.

In the first aspect there is provided a liquid fertilizer composition whose components are present in amounts within stated ranges. The components include one or more triazone compounds that are substantially soluble in water, a urea compound, water sufficient in amount to obtain and retain a solution of the triazone(s), limited minor percentages of monomethylol urea and methylene diurea compounds, and potentially minor amounts of dimethylol urea and hexamethylenetetramine compounds.

One or more triazone compounds are present in an amount of at least about 30% and preferably more than about 35%; desirably the triazone compounds content does not exceed 40% and most preferably it is between about 35% and about 40%. The one or more triazone compounds are present in an amount in ratio to urea compounds by weight of at least about 1.

One or more urea compounds are present in an amount of about 10%, preferably about 20%, up to about 60%, preferably less than 35%, and monomethylolurea is up to about 7%. Methylene diurea compounds may be present up to about 3%, preferably less than about 2.5%, and the monomethylolurea compounds may be present up to about 7%, preferably less than about 3%, preferably with the amount of monomethylolurea compounds plus methylene diurea compounds not exceeding about 5%. The ratio of triazone(s) on a dry weight basis, to methylene diurea compounds is at least about 6%, preferably at least about 11. Hexamethylenetetramine compounds may or may not be present in an amount of up to about 2%, preferably up to about 1% or less, normally there being no hexamethylenetetramine present.Typically, dimethylol urea compounds are present in an amount of no more than about 3% and most preferably 2.75%. If dimethylol urea is present the maximum content of urea compounds may be increased by the amount of dimethylol urea present.

The above percentages are calculated on a dry weight basis of 100% solids.

The improved lower urea content in the product is to achieve both lower phototoxicity and higher triazone content. Naturally there are broad ranges for many of the parameters of the invention within which some degree of success may be obtained, but with optimum results being achieved by the preferred parameters.

In a preferred embodiment of the invention the fertilizer composition comprises a mixture of triazone compounds a major amount of which mixture on a weight percentage basis is triazones having the formulae:

of total triazone, the triazone of formula (I) on a weight basis normally amounting to substantially 80% or more, in order to obtain preferred results.

The composition of the invention may be prepared by reacting, by the method described below, a urea compound, an aldehyde and ammonia or an amine, in the presence of water.

In the first step of the process, a urea compound, an aldehyde and ammonia or a primary amine are reacted or mixed in aqueous solution. Preferred results may be obtained by maintaining the temperature below 65"C and preferably below 60"C.

During the next phase of the process, reaction of the above-noted reactants is achieved by heating the admixture thereof at a temperature within a range of from about 80"C to about 95"C for a period of time ranging from about 15 minutes to about 1 hour while maintaining the pH within the range of about 8 up to about 9.5 by adding a strong base, as pH tends to drop during that reaction period; during this second phases of the process, the mole ratio of urea compounds to aldehyde must be maintained at least during a dominant or substantial portion of the phase during the earlier part thereof at between about 0.5 and about 2, and likewise the mole ratio of ammonia or amine to aldehyde should be maintained within a range of from about 0.15 to about 0.65.On a weight basis of ammonia, relative to weight basis of 100% of reactants, the ammonia or amine must be reacted in an amount within a range of from about 2% to about 6%, relative to above-noted reactants on a weight basis of total water solution weight.

Following the first stage of heating, heating is continued within the same temperature range, for an additional period of up to about 1 hour, preferably 10-30 minutes, so as to result in a reaction product of which triazone compounds thereby produced relative to unreacted amounts of urea compounds on a weight basis have a ratio of at least about 0.48. Generally during this second heating period the pH is allowed to decrease by reducing or more usually terminating the addition of base.

In order to have the stability of the composition of fertilizer of this invention, the method must be limited to the above stated maximum amounts of compounds such as the monomethylol urea, dimethylol urea and methylene diurea because of their low and limited water solubility and instability insofar as tending to crystalize and/or precipitate out. Substantially the same thing is true for hexamethylenetetramine that is likewise limited in its maximum permissible amount in the inventive composition.

For the above-stated method, optimal results may be obtained using the following preferred conditions. During the first heating phase, the reaction temperature is maintained at between about 85"C and about 93"C, more preferably between about 87"C and about 92"C. Although we have found by experiment that the broader temperature range of about 80-95"C appears to produce the desired composition, we have found that for a commercially viable process a temperature of between about 87 and 92"C is to be preferred. The period of first-phase heating preferably ranges between about 20 minutes and about 30 minutes. The mole ratio of the urea compounds to aldehyde is preferably maintained between about 0.5 and 1.2, more preferably between about 0.9 and 1.2, and the ammonia or amine to aldehyde mole ratio is about 0.25 to about 0.65. Desirably, the amount of ammonia or amine is maintained at from about 4% to about 6% by weight with the total nitrogen content of the solution being between 16 and 31% by weight. The pH should preferably be between about 8.5 and 9.

The second, final phase, of heating preferably lasts from about 10 minutes to about 30 minutes, and the reaction temperature is preferably maintained at from about 87"C to about 92"C.

In the product composition, the desired triazone is believed to be in equilibrium with the methylene diurea compounds, monomethylol urea compounds and hexamethylene compound, as well as dimethylol urea compounds, and the removal of these undesirable end products is thus not possible.

The urea compound reactant may either be urea, thiourea or a substituted urea or thiourea derivative. The substituent will not materially affect the chemistry of the urea or of the reaction products thereof, for example the solution stability and biological acceptability of the components of the fertilizer composition will not be harmed. Acceptable substituents include aliphatic groups, especially lower aliphatic groups (e.g. containing 1 to 4 carbon atoms) and more especially lower alkyl groups. It is contemplated that the aliphatic group may be substituted by acceptable substituents, e.g. a secondary amine group. Preferably the urea compound is urea or, less preferably, mono- or di-methyl- or ethyl-urea. When a mixture of urea compounds is used, a major proportion thereof is urea or, less preferably, thiourea or methyl urea.Ethyl urea is also very acceptable as the major proportion of such a mixture.

The aldehyde is generally formaldehyde or an alkanal, esepcially a lower (e.g. C,-C4) alkanal, e.g. acetaldehyde or propionaldehyde. When formaldehyde is used it may be in the form of paraformaldehyde. It is envisaged that other aldehydes may be used so long as the resultant product(s) are acceptable, e.g. as to solution stability, for example in general aliphatic aldehydes.

When a mixture of aldehydes is used a major amount is preferably formaldehyde; good results are also obtained if a major portion is acetaldehyde. We prefer to use formaldehyde, acetaldehyde or a mixture thereof.

The ammonia may be introduced into the reaction mixture as aqueous ammonia or anhydrous ammonia. As suitable primary amines there may be mentioned aliphatic amines, e.g. lower alkylamines, alkanolamines and alkylenediamines. Specific examples of useful compounds are methylamine, ethylamine, methylolamine, ethanolamine and ethylenediamine.

Especially when using urea, formaldehyde and ammonia as reactants, an optimum urea: aldehyde: ammonia/amine ratio is about 1.2:1:0.25.

At least a portion of the urea and aldehyde may be added as an already partially condensed urea-aldehyde, especially urea formaldehyde, product. A portion, generally a minor portion of the urea and aldehyde compounds may be added as hexamethylene tetramine or analogous compounds-this is not so preferred, however.

Urea aldehyde mixture, as commercially available, is normally of pH range of about 7.5 to about 9; old solution that might have a lower pH which should be adjusted to pH 7.5-9 for preferred results.

In the liquid fertilizer composition, the triazone compound or compounds will be substituted in accordance with the substituents (if any) of the reactants, and the same will appiy to the urea compounds, including the methylene diurea compounds and monomethylol urea compounds and also to hexamethylenetetramine. The terms triazone compounds" "methylene diurea compounds", "monomethylol urea compounds, "dimethylol urea compounds" and hexamethylenetetramine compounds" will be understood accordingly.

As will be seen from the foregoing discussion, the fertilizer composition may be said to contain from about 10% to 50% of urea and/or inertly substituted urea compounds. By "inertly" substituted is meant substituents as referred to above, which do not affect the solution stability and this expression excludes methylene diurea, monomethylol urea and analogous compounds.

It is noted that the development of the process of the present invention, and the eventual production of the novel compositions thereof, resulted from the finding and recognition that the previously available liquid fertilizer concentrates, such as obtained from the process of US 3462256, had unreliable shelf life as to the period of stability prior to crystallization and/or precipitation, rendering the products commercially useless and commercially impractical for foliar application, the shelf life having been observed to be variable from batch.For the method of the present invention it has been determined that stable products cannot be made with less than about 2% of ammonia (by weight of ammonia relative to about total weight of reactants) up to about 6% ammonia, and that stable product(s) cannot be made at temperature(s) higher than about 95"C, generally 93"C, and that it is difficult to make stable products at a pH above about 9.5. During the developing of this invention, it was determined that the pH of the reactant-mix, the reaction temperature, and the mole % of ammonia (or primary amine), were all much more critical to the reaction than had been previously believed.

Also, the present inventor discovered that monomethylolurea and dimethylolurea convert to methylenediurea on standing at ambient temperature and typically over a period of several weeks, causing solids to deposit. Moreover, it has been found that methylol compounds when reacted with urea at low temperatures merely sufficiently high to dissolve the urea over a period of about 15 minutes result in an unstable mixture, due to slow reactions at ambient temperatures to form methylolureas, such product being typically produced by US Patents 4,304,588 and 4,244,727, in which patents monomethylol urea is identified as a product.It was further discovered by the inventor, that the concentration of methylene diurea is a major limiting factor to the storage stability of the products of the present invention, and that the amount of methylenediurea converted from urea, should not exceed about 3% on a weight-basis, in order to insure adequate storage life from a commercial viewpoint of utility of a liquid fertilizer product.

Also, because each of monomethylol urea and dimethylol urea have been found to be unstable in solution and tend to convert to urea and methylene ureas, each, especially monomethylol urea, should be kept to a minimum, as previously stated herein.

While the inventor is not to be bound by any hypothesis of the exact reactions that occur, studies and research conducted by the present inventor indicate that triazones of the present invention are formed as a result of serially consecutive reactions as follows. Urea reacts with formaldehyde, for example, to produce monomethylol urea; the monomethylol urea reacts with formaldehyde, for example, to produce dimethylol urea; and typically methylamine reacts with the dimethyiol urea to produce a methyl triazone, or ammonia reacts with dimethylol urea to produce a hydrogen triazone (S-tetrahydrotriazone), for example.

In experiment(s) using hexamethylenetetramine as the source of ammonia, it was found that the reaction proceeds very slowly and that an unsatisfactory product is formed which rapidly crystallizes on standing. A large percentage of the hexamethylene-tetramine remained unreacted.

Also, in the method, too little ammonia and/or too much formaldehyde (or other aldehyde) results in too high a percentage of unreacted urea. When on a dry weight basis the ratio of triazone to methylene diurea of the final reaction product is less than about 6, the yield of triazone is unsatisfactorily low and, accordingly, the method of the invention maintains the methylene diurea in the final product at a satisfactory minimum.

The product of this invention is prepared by mixing together the required amount of urea compound, aldehyde and ammonia or amine in an aqueous solution, as a typical example. The mixture is heated thereafter to a carefully controlled temperature, maintained within the required temperature range for a specific length of time while also carefully controlled as to pH during the initial first phase of heating and reacting with a slow addition of strong aikali. Thereafter, the temperature is maintained within the same range for a second phase heating period to bring about a completion of the reaction. The batch is then cooled and packaged.

In a preferred method of the invention, improved product content may be obtained by cooling the reaction product promptly after the second stage heating period, down to a lower temperature below about 40"C, especially between about 33"C and about 37"C.

The order of addition of the source of urea, aldehyde, ammonia or amine and water are not considered to be very important provided there are no prolonged periods of time of adding a final ingredient and provided imbalance of reactants in the required necessary amounts is not permitted for any significant period during reaction, and provided the one or more admixed reactants are not permitted to sit in an unreacted state for any unreasonable or prolonged period of time.

The urea may be added either as pelleted or crystal urea, as urea solution or at least partially as an already partially condensed urea-formaldehyde reaction product. The formaldehyde may be added as commercially available formaldehyde solution or as paraformaldehyde, or partially in the form of hexamethylenetetramine or as an already partially condensed urea/formaidehyde product.

The ammonia may be added as anhydrous or aqueous ammonia or partly in the form of hexamethylenetetramine. The total nitrogen in the solution should generally be between at least 16% and 31% or more or a weight basis of the total reaction product solution which may be later diluted.

Because, as noted above, it has been proven impossible to obtain stable liquid urea-formaldehyde fertilizer solutions when following the procedures of prior art patents and literature, due to the limited solubility of monomethylol urea, dimethylol urea and methylene diurea and also due to the inherent instability of these materials, it therefore became necessary for the present inventor to separate and to identify the components of the reaction products of the present invention of liquid fertilizer solution.

High pressure liquid chromatograph was used to separate the separate reaction products prepared by the method of this invention, and prepared by related methods. Most of its components were identified by the preparation of pure compounds and running them as standards on the liquid chromatograph (HPLC).

One major component could not be identified by this procedure.

Paper chromatographic separation was used to concentrate this unknown component which was subsequently purified by recrystallization and identified as the unknown by further HPLC analysis.

This invention sample was then analysed by mass spectrophotometric, NMR, infrared and by an elemental analyzer, and determined to be an 80/20 mixture of S-tetrahydrotriazone of Formula (I) above (empirical formula C3H7N3O) and N-hydroxymethylformamide triazone of Formula (II) above (empirical formula CsHIoN4o3) Suitable alkali includes any one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate or other strong bases.

The triazones within the contemplation of this invention as liquid fertilizer suitable for application to foliage and/or soil, include the relatively few triazones that are characterized by being substantially soluble in water, most being insoluble.

In its third aspect, the invention relates to a method of fertilizing vegetation and/or soil comprising applying to plant foliage and/or soil a liquid fertilizer composition of the invention.

Preferably, the fertilizer composition is applied to foliage.

In a preferred embodiment there is provided a method of fertilizing vegetation comprising applying to vegetation foliage, a water solution of fertilizer consisting essentially of, as calculated on a dry weight basis of 100% solids: one or more triazone compounds that are substantially soluble in water in an amount of at least 30%; one or more inertly substituted urea compounds in an amount of from 20% to 50%, the triazone compound: urea compound ratio being at least 0.48:1; the composition containing not more, than the indicated amounts (dry weight basis) of the following compounds: methylene diurea compounds 3% monomethylol urea compounds 6% (methylene diurea compounds + monomethylol urea compounds) 6% hexamethylenetetramine compounds 2% and the composition containing water in an amount at least sufficient for solution of all the above compounds, and the triazone compound: methylene diurea compound ratio being at least 6:1 on a dry weight basis.

More preferably the triazone compound content is from 35% to 40%, the urea compound content is up to 35%, the triazone compound: urea compound ratio being at least 1:1 the methylene diurea compound content being not more than 2.5%, the monomethylol urea compound content being not more than 3%, with the total (methylene diurea compound plus monomethylol urea compound) content not more than being 5%, and the hexamethylenetetramine compound content being not more than 1%, the triazone compound: methylene diurea compound ratio being at least 11:1.

The liquid fertilizer products of this invention were compared to certain other chemical and commercial products with regard to phototoxicity, as follows. When averaged over all four species of turf, grasses for St. Augustine, Hybrid Bermuda, Fescue and Perennial Ryegrass, for a series of tests employing different numbers of pounds per square foot as the N rate, ureatriazone mixture of this invention was less phytotoxic than Formolene or urea by 37.5% and 44.4%, respectively, at the most commonly used rate of N on turf (1 lb/1,000 sq. ft.). When averaged over all species and rates, urea-triazone mixture of this invention was 6.6% and 30% less phytotoxic than Formolene and urea, respectively.

Urea-triazone of this invention is substantially safer than Formolene when applied at 2.65 Ibs N/1000 sq. ft. (an undiluted application). Accordingly, the triazones (urea-triazones) above-identified for this invention, are a safer turf nitrogen than the other items above-tested for comparable uses.

Likewise, for the DOT skin corrosion tests, the triazone products of this invention were found to be not corrosive.

Following are typical runs, some by the method of this invention, and others comparative, to illustrate the invention.

EXAMPLE I (samples 1-2, 2-2, 3-2, 4-2, tested at one point in time) (Based on water soln.wt) Components of Percentage Dresent bv weight reaction Product 1-2 2-2 3-2* 4-2* Urea 28.7 27.3 30.0 36.9 Monomethylol urea 1.8 1.8 6.1 0.9 Methylene diurea *. 0.8 1.3 1.1 1.1 Dimethylol urea 0.7 1.1 0.7 1.2 Triazone 18.8 19.6 12.9 8.2 Hexamethylenetetramine... - - - 2. 9 * Comparative The Sample 3-2 having a monomethylol urea (MMU) percentage of 6.1 % had poor stability, the methylene diurea crystallising out as the monomethylol decomposed when stored for a short period on the shelf.Likewise, the sample 4-2 was unsatisfactory in its yield of triazone, at 8.2%, as a result of the final product having a high concentration of unreacted urea at 36.9% and as well there being present an unsatisfactorily large percentage of hexametheylene-tetramine at 2.9%, causing also instability resulting in crystallization and precipitation of components, rendering the product totally unsatisfactory for use as a liquid foliar feed.From the above table of which the balance of percentage for each sample is water, the percentages present on a basis of total solids are: 1-2 2-2 3-2 4-2 Urea 56.50 53.33 59.04 72.00 Monomethylol urea (MMU).. 3.54 3.52 12.01 1.76 Methylene diurea (MDU)... 1.57 2.54 2.17 2.15 Dimethylol urea (DMU).... 1.37 2.15 1.41 2.34 Triazone 37.01 38.28 25.89 16.02 Hexamethylenetetramine... - - - 6.36 Wt.ratio of Triazone/urea 0.65 0.72 0.43 0.22 Wt.ratio of Triazone/MDU 23.5 15.1 11.7 2.6 Four days later, again the components percentage after that additional shelf-life, were tested, giving the following results for the above-noted samples.

on on basis on total water solution) Components of 1-2 . 2-2 3-2 4-4 5-1 reaction Product (prior run) Urea 29.4 27.9 30.0 35.5 28.7 less than 0.1 0.8 5.3 0.4 2.3 MDU 0.9 1.2 1.2 1.2 1.2 DMU 0.5 0.5 0.8 1.0 0.6 Triazone 20.0 20.4 13.7 9.5 18.3 Hexamethylene- - - - 6.36 tetramine The solids percentages by weight for this preceding table are: (1-2) (2-2) (3-2) (4-2) (5-1) Urea 57.7 54.9 59.5 69.9 56.2 MMU 0.2 1.6 10.5 0.8 4.5 MDU 1. 8 2.4 2.4 2.4 2.4 DMU 0.98 0.98 0.4 1.2 1.2 Triazone 39.3 40.2 26.9 18.7 35.8 Hexamethylene- - - - 5.7 - tetramine As can be seen, the amount of hexamethylenetetramine is high and the triazone is low for experiment 4-2.

Some of the preferred triazones of this invention include S-tetrahydrotriazone, methyltriazone and beta-ethanoltriazone.

For the several above-noted reaction products of the preceding Example I, the formulations utilized and the common method applied to each were as follows: Formulation(wt.%) 1-2 2-2 3-2 4-2 Urea: 52.3 52.3 52.3 48.5 25% Urea-60% Formaldehyde: 31.3 31.3 31.3 29.0 KOH Soln. (25%): 3.0 3.0 0.3 0.3 A4ua Ammonia (28% NH3): 10.7 10.7 10.7 19.7 Water: 2.7 2.7 5.4 2.5 Mole ratio (urea/HCHO/NH3): 1.6/1/.28 1.6/1/.28 1.6/1/.28 1.6/1/.56 The procedures followed for the above-noted formulations, were as follows: 1-2: Water, urea-formaldehyde and the urea were mixed together in a reaction kettle and slowly the aqueous ammonia was added while mixing.That mixture was heated to 83"C and maintained at a temperature below 90"C and at a pH between about pH 8.7 and pH 9 for 45 minutes, pH being maintained by the addition of the KOH. Thereafter, further heating and reaction were accomplished by maintaining the temperature to the reactants at between 83"C and about 90"C for an additional 15 minutes. Thereafter, the reaction product was permitted to cool and was packaged.

2-2: The water, urea-formaldehyde and the urea were mixed together in a reaction kettle and pH was adjusted to pH 9.0 by addition of KOH. That mixture was then heated to 81"C and the pH during the heating was maintained at between 8.7 and 9.0 by continual additions of KOH NH3 mixture while heating to 90"C. The temperature was thereafter maintained at between 88 and 90"C at a pH ranging from 8.7 to 9.0 until all of the KOH-NH3 mixture had been added.

Thereafter the mixture was heated and the temperature was maintained at between 88 and 90"C for an additional 15 minutes, following which the reaction product was allowed to cool, after which it was packaged.

3-2: The water, urea-formaldehyde and urea were mixed in the reaction kettle and the pH was adjusted to 9.5 with addition of the KOH solution. The mixture of reactants was then heated to about 73"C at which point the urea was completely dissolved, and thereafter the reaction mixture was maintained at a pH of 8.5 to 9.0 with a slow addition of aqueous ammonia for approximately 10 minutes while heating to 90"C. Thereafter heating and maintaining reactants at 88 to 90"C were continued for an additional 30 minutes, followed by permitting the reaction product to cool and then by packaging the reaction product.

4-2: The same steps were followed as for 3-2 above, except as follows. The addition of aqueous ammonia was started at about 75"C and pH was maintained between 8.5 and 9.0 by a slow addition of the KOH while heating the reactants to 90"C for approximately 18 minutes.

Thereafter the reactants temperature was maintained by heating, at between 88 and 90"C for an additional 3 minutes.

From the above procedures, which resulted in the reaction products already discussed, it will be seen that the limitations of this invention are in fact critical. It is also noted that in the 3-2 procedure, the first-phase addition of aqueous ammonia for the ten minutes, was not the equivalent of use of a strong base such as KOH and proved to be unsatisfactory and unacceptable for the method of the present invention. It is also noted that the pH 9.5 of procedure 3-2, was slightly above the broad range of the method of this invention, and that the yield was reasonably poor, as compared for example, to the much higher yields of 1-2 and 2-2. The reaction product of 4-2 crystallized when permitted to stand (shelf-life) for 72 hours.

EXAMPLE 11 Another series of experiments were designed in order to determine and illustrate the effects of various reaction conditions on the quality of the product. The first of the conditions investigated was the percentage of ammonia in the cook. This was varied from 0% to 3.0% (on the basis of weight of the water solution) with the following results.

Run No.: 1 2 3 4 5 6 Reactant or Product % NH3 0 1.0 1.5 2.0 2.5 3.0 Unreacted urea 31.8 30.6 34.8 37.7 34.7 35.8 MMU 20.2 4.3 7.1 1.8 1.7 Tr.

MDU 27.7 14.2 15.8 7.9 5.9 7.7 DMU 18.2 7.1 Tr. Tr. Tr. Tr.

Triazone(s) 1.3 43.8 42.3 52.6 57.7 56.5 (tpe Water soln.) Tr. = Trace The runs Nos. 4, 5 and 6 illustrate the method of the present invention. Runs 1, 2 and 3 are comparative.

For the above-note runs, ratio of triazone(s) to MDU and of NH2 to formaldehyde, and to triazone(s) to unreacted formaldehyde, were as follows: 1 2 3 4 5 6 triazone(s)/MDU 0.08 5.9 5.0 12.5 18.2 13.7 (weight basis) NH3/HCHO 0.0 0.09 0.14 0.18 0.23 0.28 (mole ratio) triazone(s)/un- 0.013 0.46 0.39 0.45 0.54 0.51 reacted urea (weight basis) It is noted particularly that triazone(s)/MDU ratios of runs 1, 2 and 3 were all below 6, and that the resltant yields were poor for the triazone(s), the % NH3 reactant for those runs being far below the required limitations of the method of this invention.

It is noted that the run No. 4 had insufficient ammonia reactant which results in excessive unreacted urea and also in a product of poor instability, i.e. quick crystallization and precipitation and a poor shelf-life resulted, even though the yield of the triazone(s) was reasonably acceptable.

Also these tests show that ammonia or an amine is necessary for production of a storage stable composition that includes the triazone products in acceptable yields, within the range of the method of this invention, and the importance of the ratio limitations.

It is within the scope and contemplation of this invention, to make such variations and modifications and substitution of equivalents as would be apparent to a person having ordinary skill in this particular art.

For the following two examples of products produced within the preceding preferred parameters, the content based on analysis, on a wet (solution) basis, was as follows, where the processes employed a urea/formaldehyde ratio of 1.2, as contrasted to prior examples herein having had a ratio of 1.6.

Batch # : #1 *2 % urea 19.5 20.2 S MMU 3.8 4.3 %MDU 1.8 1.8 % Triazone 30.8 28.8 Triazone/urea ratio 1.58 1.43 (by weight/dry) Triazone/MDU 17.1 16.0 (by dry weight) For the above data. expressed on a dry basis, the analysis is: % urea: 32.5 33.7 %MMU 6. 3 7. 2 %MDU 3.0 3.0 $Triazone 51.3 48

Claims (35)

1. A liquid fertilizer composition comprising, as calculated on a dry weight basis of 100% solids: one or more substantially water soluble triazone compounds in an amount of at least 30%; one or more urea compounds in an amount of from 10% to 60%, the triazone compound: urea compound weight ratio being 0.48:1 or more; and water, the composition containing not more than the indicated amounts (dry weight basis) of the following urea compounds and of hexamethylenetetramine compounds: methylene diurea compounds 3% monomethylol urea compounds 7% hexamethylenetetramine compounds 2%, all the above compounds being dissolved in the water and the triazone compound: methylene diurea compound weight ratio being 6:1 or more.

2. A liquid fertilizer composition as claimed in claim 1, in which the triazone compound content is between 35% and 50%, the urea compound content is not more than 35%, the triazone compound: urea compound ratio being 1:1 or more, the methylene diurea compound content is not more than 2.5%, the monomethylol urea compound content is not more than 3%, with the total dry weight of methylene diurea compounds and monomethylol urea compounds being not more than 5%, and the hexamethylenetetramine compound content is not more than 1%, the triazone compound: methylene diurea compound ratio being 11:1 or more.

3. A liquid fertilizer composition as claimed in claim 1 or claim 2 in which a major portion on a dry weight basis of the triazone compounds are of the formula:

4. A liquid fertilizer composition as claimed in claim 3, in which a minor portion of the triazone compounds are of the formula:

5. A liquid fertilizer composition as claimed in claim 3 or claim 4 in which the triazone compound of formula (I) constitutes at least 80% of all triazones present, on a dry weight basis.

6. A liquid fertilizer composition as claimed in claim 1 or claim 2 which includes triazone compounds having empirical formulae C3H,N3O and CbH,0N403.

7. A method for producing a water solution fertilizer composition of substantially stable water-soluble components as a reaction product containing one or more substantially watersoluble triazone-type compounds, comprising: (a) reacting in aqueous solution a urea compound, an aldehyde and ammonia or a primary amine;; (b) thereafter further reacting in a first heating stage at a temperature between 80"C and 95"C for an additional reacting period of from 1 5 minutes to 1 hour while adding as necessary during the additional reacting period a strong base to maintain the pH within the range of 8 to 9.5 and while adding as necessary during the additional reacting period the urea compound and the aldehyde to maintain a mole ratio of the urea compound to the aldehyde within the range of from 0.5 to 2, and while adding as necessary during the additional reacting period ammonia or the amine to maintain a mole ratio of ammonia or amine to the aldehyde within a range of from 0.15 to 0.65, the ammonia or amine being reacted in an amount ranging from 2% up to 6% on a total water-mixture weight basis of 100% of reactants of the urea compound, the aldehyde and the ammonia or amine; and (c) thereafter as a second heating stage maintaining the reaction temperature between 80"C and 95"C for a further period up to 1 hour, such that the final reaction product has a triazone compound: unreacted urea compound weight ratio of at least 0.48.

8. A method as claimed in claim 7 wherein the temperature in stages (b) and (c) is between 85"C and 93"C.

9. A method as claimed in claim 7 or claim 8 in which during stage (b) the temperature is between 87"C and 92"C for from 20 minutes to 30 minutes, the urea compound: aldehyde molar ratio is from 0.9:1 to 1.2:1, the ammonia or amine: aldehyde mole ratio is from 0.25 to 0.65, and the ammonia or amine is in an amount from 4% to 6% such that total nitrogen on a basis of total weight of solution is between 16% and 31%; and in which stage (c) lasts from 10 minutes to 30 minutes.

10. A method as claimed in any one of claims 7 to 9 in which as the aldehyde there is used formaldehyde or a mixture of aldehydes a major portion of which is formaldehyde.

11. A method as claimed in any one of claims 7 to 9 in which as the aldehyde there is used acetaldehyde or a mixture of aldehydes a major portion of which is acetaldehyde.

12. A method as claimed in any one of claims 7 to 11, in which as the urea compound there is used urea or a mixture of urea compounds of which a major portion is urea.

13. A method as claimed in any one of claims 7 to 11 in which as the urea compound there is used thiourea or a mixture of urea compounds a major portion of which is thiourea.

14. A method as claimed in any one of claims 7 to 11 in which as the urea compound there is used methyl urea or a mixture of urea compounds a major portion of which is methyl urea.

15. A method as claimed in any one of claims 7 to 14 in which as the ammonia or amine there is used ammonia or a mixture of ammonia and one or more amines of which a major portion is ammonia.

16. A method as claimed in any one of claims 7 to 14 in which as the ammonia or amine there is used methylamine or mixture of amines or of one or more amines and ammonia, a major portion of which is methylamine.

17. A method as claimed in any one of claims 7 to 14 in which as the ammonia or amine there is used monoethanolamine or a mixture of amines or of one or more amines and ammonia, a major portion of which is monoethanolamine.

18. A method as claimed in any one of claims 7 to 14 in which as the ammonia or amine there is used ethylenediamine or a mixture of amines or of one or more amines and ammonia, a major portion of which is ethylenediamine.

19. A method as claimed in claim 9 in which the aldehyde comprises formaldehyde, the urea compound comprises urea, and the ammonia or amine reactant comprises ammonia.

20. A method as claimed in claim 19 in which the aldehyde is formaldehyde, the urea compound is urea, and the ammonia or amine reactant is ammonia.

21. A method as claimed in any one of claims 7 to 20, in which the temperature is maintained below 65"C during stage (a) of claim 7.

22. A method as claimed in claim 21, in which the temperature is maintained below 60"C duririg stage (a) of claim 7.

23. A method as claimed in any one of claims 7 to 22, in which a strong base is added as necessary to the aqueous solution to adjust the pH thereof to within a range of from 7.5 to 9 prior to the stage (a) reaction.

24. A method as claimed in any one of claims 7 to 23 including, immediately subsequent to completion of stage (c), cooling the reaction product thereof to a temperature of from 33 to 37"C.

25. A method as claimed in claim 7 and substantially as hereinbefore described.

26. A liquid fertilizer composition whenever prepared by a method as claimed in any one of claims 7 to 25.

27. A method of fertilizing vegetation and/or soil comprising applying to vegetation foliage and/or soil a triazone fertilizer composition as claimed in any one of claims 1 to 6 or 26.

28. A method as claimed in claim 27, in which the triazone compound is hydrogen-triazone (S-tetrahydrotriazone) .

29. A method as claimed in claim 27, in which the triazone compound is methyl-triazone.

30. A method as claimed in claim 27, in which the triazone compound is beta-ethanoltriazone.

3 1. A method of fertilizing vegetation comprising applying to vegetation foliage, a water solution of fertilizer consisting essentially of, as calculated on a dry weight basis of 100% solids: one or more triazone compounds that are substantially soluble in water in an amount of at least 30%; one or more inertly substituted urea compounds in an amount of from 20% to 50%, the triazone compound: urea compound ratio being at least 0.48:1; the composition containing not more, than the indicated amounts (dry weight basis) of the following compounds: methylene diurea compounds 3% monomethylol urea compounds 6% (methylene diurea compounds + monomethylol urea compounds) 6% hexamethylenetetramine compounds 2% and the composition containing water in an amount at least sufficient for solution of all the above compounds, and the triazone compound: methylene diurea compound ratio being at least 6:1 on a dry weight basis.

32. A method of fertilizing vegetation as claimed in claim 31, in which the triazone compound content is from 35% to 40%, the urea compound content is up to 35%, the triazone compound: urea compound ratio being at least 1:1, the methylene diurea compound content being not more than 2.5%, the monomethylol urea compound content being not more than 3%, with the total (methylene diurea compound plus monomethylol urea compound) content being not more than 5%, and the hexamethylenetetramine compound content being not more than 1%, the triazone compound: methylene diurea compound ratio being at least 11:1.

33. A method of fertilizing vegetation as claimed in claim 31 or 32 wherein a major portion, on a dry weight basis, of the triazone compounds is 5-tetrahydrotriazone.

34. A method of fertilizing vegetation as claimed in claim 33 wherein the triazone compounds further include N-hydroxymethylformanide triazone.

35. A liquid fertilizer composition comprising, as calculated on a dry weight basis of 100% solids: one or more substantially water soluble triazone compounds in an amount of at least 30%; one or more of uea and inertly substituted urea derivatives in an amount of from 10% to 50%, the triazone compund: (urea+urea derivative) ratio being substantially 0.48:1 or more; and water, the composition containing not more than the indicated amounts (dry weight basis) of the following compounds: methylene diurea compounds 3% monomethylol urea compounds 7% hexamethylenetetramine compounds 2%, all the above compounds being dissolved in the water and the triazone compound: methylene diurea compound ratio being substantially 6:1 or more.