GB2166974A

GB2166974A - An evaporation inhibitor

Info

Publication number: GB2166974A
Application number: GB08526995A
Authority: GB
Inventors: Josef Koster; Adolf Asbeck; Holger Tesmann; Margarete Grunert; Karl Schmid; Konrad Albrecht; Paul Bittner; Fritz Keim
Original assignee: Henkel AG and Co KGaA; Hoechst AG
Current assignee: Henkel AG and Co KGaA; Hoechst AG
Priority date: 1984-11-14
Filing date: 1985-11-01
Publication date: 1986-05-21
Also published as: HUT38795A; EP0185185B1; KR860003776A; MX9206187A; GR852752B; AU4985185A; DE3575514D1; DK523985D0; DK165158B; ES8704706A1; MY101422A; PL255501A1; MA20573A1; KE3836A; EP0185185A1; PH23126A; AR242334A1; CA1318495C; BR8505708A; AU580811B2

Description

1 GB 2 166 974 A 1

SPECIFICATION An Evaporation Inhibitor

Agricultural chemicals are widely used nowadays to safeguard the growth and yield of crops, having to be applied in particular by airplane to cover the large areas under cultivation. To minimize the costs involved, every effort is made to keep the quantities of water required for diluting the commercial concentrates as small as possible and to apply high concentrations of active compound in small amounts. Today, quantities of from 5 to 50 liters/ha are applied by the low-volume (LV) method using known commercial products, such as wettable powders (WP) suspended concentrates (SC) or solvent-containing emulsifiable concentrates (EC) which are normally sprayed in suspension in 300 to 600 liters of water/ha 10 using ground appliances.

The smaller the quantities of spray mixture applied per unit area, the finer the droplets applied have to be to obtain satisfactory coverage of the crops. This plus the high concentration of the spray mixtures has hitherto created the main obstacle to application of the low-volume method, particularly under sub-tropical and tropical climatic conditions, namely: the water evaporates too quickly on account of the large surface of 15 the fine droplets, so that increased drifting losses can occur.

In addition to drifting losses, damage may even be caused to adjacent crops, depending on the plant treatment agent used. Accordingly, controlled application from air-craft is difficult; damage to the environment or losses of harvest may have to be accepted.

In addition, heavy foaming can occur during preparation of the spray mixture with the greatly reduced quantities of water, because the dispersants and wetting agents in the wettable powders or concentrated 20 dispersions are then present in correspondingly higher concentrations. The product foams out of the spray tanks unless the filling level is greatly reduced.

The spray mixtures in question of agricultural chemicals are prepared from commercial concentrates by dispersion or emulsification in the desired quantity of water. The concentrates are either self-emulsifying solutions in an organic solvent (EQ or wettable powders (WP) or suspended concentrates (SC).

The agricultural chemicals used maybe insecticides, fungicides, virucides, herbicides, acaricides, desiccants, growth regulators, ripening accelerators, repellents, pheromones, leaf fertilizers, defoliants, etc.

In addition, the concentrates optionally contain dispersants, emulsifiers, wetting agents, defoamers, stickers, carriers and pigments for obtaining a marking effect.

The object of the present invention is to reduce the evaporation of water in the application by the 30 low-volume method of agricultural chemicals in the form of spray mixtures. Measures in that direction are the subject of DE 22 05 590, although the mineral-oil-based evaporation inhibitors claimed therein are not sufficiently effective under sub-tropical and tropical climatic conditions. In addition, it is known from US-PS 3 791839 that the release of water from living plants, particularly during growth in dry climates, can be reduced by applying to the surface of the plants an aqueous emulsion which, in addition to paraffin wax 35 and emulsifier, contains vaseline- like hydrocarbons (petrolatum). However, the function of these emulsions is not to reduce the evaporation of spray mixtures of plant protection agents during spraying by the low-volume method.

The present invention relates to an evaporation inhibitor (EI) for spray mixtures of agricultural chemicals applied by the LV method in the form of a wax-containing aqueous dispersion or self-emulsifying 40 solution in an organic solvent, characterized by the following composition:

from 15 to 50% by weight of a wax or wax mixture, from 4 to 20% by weight of nonionic and/or anionic emulsifiers, from 19.5 to 81 %by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points of from 70 to 2800C, from 0 to 5.5% by weight of auxiliaries, from 0 to 5.0% by weight of amines or alkali.

The inhibitor preferably has one of the following compositions X or Composition X from 15 to 40% by weight of paraffin waxes or a wax mixture containing paraffin waxes having a 50 dropping point of from 35 to 80'C, from 4to 20% by weight of nonionic and/or anionic emulsifiers, from 35 to 81 % by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points of from 70 to 280'C, from 0 to 5.5% by weight of other auxiliaries.

Of inhibitors having the composition X, it is preferred to use those formulated as aqueous dispersions having the following composition:

from 15 to 40% by weight of paraffin waxes or of a mixture of paraffin waxes having different dropping points in the range from 35 to 700C or of a mixture of those paraffin waxes with microcrystailine 2 GB 2 166 974 A 2 waxes having dropping points of from 50 to WC, the paraffin waxes making up at least 50% by weight of the wax mixture, from 4 to 20% byweight and preferably from 4 to 14% by weight of nonionic emulsifiers from 0 to 10% by weight and preferably from 1 to 7% by weight of anionic emulsifiers, the nonionic emulsifiers making up at least 50% by weight of the emulsifiers, from 35 to 81 % by weight of water, from 0 to 10% by weig ht of xylene or cyclohexanone or petroleum fractions having boiling points in the range from 145 to 21 O'C or esters having boiling points in the range from 70 to 2800C, from 0 to 5% by weight of hydrotropes, from 0 to 0.5% by weight of inorganic salts.

The composition Y comprises the following components:

from 15 to 50% by weight of a wax mixture containing a wax component having an acid number of from 10 to 95 mg KOH/g wax, from 4 to 20% by weight of nonionic and/or anionic emulsifiers, from 19.5 to 81 % by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points in the range from 70 to 2800C, from 0 to 5.5% by weight of auxiliaries, from 0 to 5.0% by weight of amines or alkali.

The wax mixture preferably has one of the following compositions:

Mixture (A) Mixture (B) Mixture (C) from 60 to 95% by weight of paraffin wax and/or microcrystalline paraffin wax having a setting point of from 40 to 70'C, from 5 to 40% by weight of oxidized polyethylene wax having a dropping point of from 95 to 1400C and an acid number of from 10 to 9. mg KOH/g wax.

from 60 to 95% by weight of paraffin wax and/or microcrysta I line paraffin wax having a setting point of from 40 to 700C, from 5 to 40% by weight of wax containing ester bonds and having a dropping point of from 75 to 1 OO'C and an acid number of from 10 to 95 mg KOH/g wax.

from 20 to 50% by weight of paraffin wax having a setting point of from 30 to WC, from 50 to 80% by weight of oxidized paraffin wax having a setting point of from 60 to 900C and an acid number of from 10 to 95 mg KOH/g wax.

The present invention also relates to a process for reducing the evaporation of water from spray mixtures of agricultural chemicals during application by the LV method, characterized in that from 1 to 15% 35 by weight and preferably from 5 to 10% by weight of an evaporation inhibitor corresponding to the above definition is added to the spray mixtures adjusted in the in-use concentration. In inhibitors having the composition X, the dropping points of the paraffin wax or wax mixture should preferably be 10 to 4WC and more especially at least WC above the particular airtemperature prevailing during application.

The inhibitors according to the invention may be present in the form of solutions of the wax and 40 emulsifier constituents in the organic solvents. Solutions such as these are temperature-stable and storable and, when stirred into water or spray mixtures adjusted to the in-use concentration, form dispersions which show high thermal stability under normal practical conditions.

However, the inhibitors are preferably used in the form of concentrated aqueous dispersions because, in that form, they are easier to incorporate in the spray mixtures through the absence or substantial absence 45 of solvents. The dispersions are prepared, for example, by melting the constituents to be dispersed (wax mixture, emulsifiers, optionally organic solvents) together and then adding the desired amount of water and, optionally, other constituents. In the case of relatively high melting wax mixtures, it can be more suitable to stir the wax mixture melted togetherwith the emulsifiers and organic solvents, if any, into the waterwhich has been heated to 60-1 OWC and preferably to 80-1 OWC and which optionally contains further constituents, followed by rapid cooling. The dispersion is distinguished by outstanding temperature stability and high stability in storage, enabling it to be used even under sub-tr6pical and tropical climatic conditions. More particularly, the claimed inhibitors are used in the form of aqueous dispersions having the following composition:

from 15to 40% byweightof wax mixture (A), (B) or(C), from 4 to 20% by weight and preferably from 4to 14% by weight of nonionic emulsifiers from 0 to 10% by weight and preferably from 1 to 7% by weight of anionic emulsifiers, the nonionic emulsifiers making up at least 50% by weight of the emulsifiers, so 3 GB 2 166 974 A 3 from 29.5 to 81 % by weight of water, from Oto 10% by weight of xylene orcyclohexanone or petroleum fractions having boiling points in the range from 145 to 2100C or esters having boiling points in the range from 70 to 280'C, from 0 to 5% by weight of hydrotropes, from 0 to 0.5% by weight of inorganic salts, from 0 to 5.0% by weight of amines or alkali.

The aqueous dispersions are particularly suitable for use in spray mixtures based on solvent-containing concentrates (EC) and wettable powders (WP). The ready-to-use spray mixtures are prepared simply by stirring the aqueous dispersion into the spray mixtures adjusted to the in-use concentration.

In the treatment of large areas, the spray mixtures are generally applied by airplane in the form of a 10 very fine spray mist, although portable or mobile appliances may be used for smaller areas.

By virtue of the present in them of wax mixtures specifically adapted to the particular in-use conditions, the claimed evaporation inhibitors greatly inhibit the evaporation of water from the droplets of spray mist during application. In this way, the droplets largely retain theirweight, resulting in an increased rate of fall and less drifting underthe effect of wind. This leads to a better effect of the plant treatment agents and, 15 hence, to increases in crop yield. On the other hand, the quantities of active ingredients may also be reduced. In addition, the fact that the quantity of liquid is maintained in the droplets of spray mixture avoids undesirable concentrations of the active ingredients, providing for slow release which can have a positive effect on the phytotoxicity of the agents used.

In addition, the wax present in the inhibitors has a foam-damping effect, thus preventing excessive 20 foaming during preparation of the spray mixtures and their introduction into tanks and the like.

The paraffin waxes used in the inhibitors consist essentially of linear C20_C4() hydrocarbons having an average molecular weight of from 280 to 560. Paraffin waxes such as these have dropping points of from 35 to 80'C or setting points of from 30 to 700C. In order reliably to obtain the evaporation-inhibiting effect even at elevated air temperatures, it is best to combine paraffin waxes having different dropping points or setting 25 points or paraffin waxes with microcrystalline waxes. In either case, however, the paraffin waxes must make up at least 50% by weight of the total wax mixture of composition X.

Microcrystalline waxes consist mainly of naphthenes with long side chains together with isoparaffins and small quantities of other aliphatic and aromatic hydrocarbons. The individual constituents contain from 30 to 60 carbon atoms in the molecule. The waxes have average molecular weights of from 580 to 700, 30 dropping points of from 50 to 900C or setting points of from 40 to 70'C.

The following products are preferably used in wax mixtures (A), (B) or (C) of the composition Y:

(a) Natural or synthetic paraffin waxes of microcrystal line paraffin waxes having setting points in the above-m entioned ranges, for example ozocerite, paraffin waxes from the distillation of petroleum, microparaffins from crude oil residues or synthetic paraffins obtained by Fischer-Tropsch synthesis.

(b) Oxidized polyethylene waxes having dropping points of from 95 to 140'C, of the type obtained by partial oxidation of polyethylenes. The acid number is preferably in the range from 10 to 70 mg KOH/g wax.

(c) Oxidized paraffin waxes having setting points of from 60 to 90'C and an acid number of from 10 to 95 mg KOH/g wax, of the type obtained by partial oxidation of paraffins.

(d) Waxes containing ester bonds, preferably emanating from natural sources, such as for example 40 montan waxes in crude or refined form, vegetable waxes, such as carnauba or candelilla wax, or insect waxes, such as shellac wax. The ester waxes have dropping points of from 75 to 100'C and are optionally used in prehydrolyzed form with an aciq number of from 10 to 95 mg KOH/g wax.

The emulsifiers used are preferably nonionic surfactants or surfactant mixtures, including for example the sorbitan esters of higher fatty acids and long-chain alkyl glycosides and also alkylene oxide adducts 45 with higher, linear monofunctional and polyfunctional alcohols, alkylphenols, longchain carboxylic acids, carboxylic acid amides and C10_C24 hydroxy fatty acids as well as with fatty acid glycerol or sorbitan esters and long-chain alkyl glycosides. It is preferred to use the adducts of from 2 to 50 moles of ethylene oxide with long-chain, more especially primary alcohols and with C12-CIS fatty acids. To improve the temperature stability of the aqueous inhibitor dispersions, it is advisable to combine two or more alkylene 50 oxide adducts differing in their degree of alkoxylation with one another. A mixture of ethylene oxide adducts with Clr-Cl, fatty alcohols or alkylphenols consisting of from 10 to 40% by weight of adducts containing from 1 to 4 moles of ethylene oxide, from 25 to 70% by weight of adducts containing from 4to 10 moles of ethylene oxide, from 5 to 35% by weight of adducts containing from 10 to 50 moles of ethylene oxide has proved to be particularly effective.

The dispersions may be further stabilized by replacing part of the nonionic emulsifiers by anionic emulsifiers. Suitable anionic emulsifiers are the alkali, ammonium, amine and alkaline-earth salts of long-chain alkyl sulfates, sulfonates and phosphoric acid partial esters. Particularly suitable anionic emulsifiers are the salts of sulfuric acid serniesters or phosphoric acid partial esters of linear alcohols or 60 alkylphenols containing from 12 to 18 carbon atoms or polyglycol monoalkylethers containing from 12 to 18 carbon atoms in the alkyl group and also olefin sulfonates, ester sulfonates and alkane sulfonates 4 GB 2 166 974 A 4 containing from 12 to 20 carbon atoms, alkylbenzene sulfonates containing from 6 to 16 carbon atoms in the alkyl groups, sulfonates of polyglycol monoalkylethers and salts of polyglycol monoalkylether carboxylic acids containing from 12 to 18 carbon atoms in the alkyl groups. Of these surfactants, alkylbenzene sulfonates and alkane sulfonates are preferably used. The emulsifiers are used in a total quantity of from 4 to 20% byweight and preferably in a total quantity 5 of from 4to 14% by weight, based on the inhibitor dispersion or solution. Where anionic emulsifiers are present, they preferably make up at least 0.5% by weight and more especially at least 1.0% by weight of the inhibitor as a whole. The nonionic emulsifiers should preferably make up at least 50% by weight of the total quantity of emulsifiers. 10 The organic solvents optionally present in the inhibitor formulations are liquid hydrocarbons, esters or 10 ketones having boiling points of from 70 to 280'C, for example light mineral oils, toluene, liquid fatty acid methyl esters and the like. Preferred solvents are xylene, cyclohexanone or petroleum fractions boiling at temperatures in the range from 145 to 21 OOC. Other auxiliaries which may be added as required in a total quantity of up to 5. 5% byweight, more especially to the inhibitor dispersions, include dyes, viscosity regulators, foam regulators, preservatives, 15 inorganic salts, hydrotropes and other dispersion aids. Of particular importance to the dispersions in this respect are hydrotropes and salts which influence the structure of the aqueous component of the dispersion and thus enable viscosity and degree of dispersion to be regulated. Preferred hydrotropes are non-surface-active salts of aromatic sulfonic acids, such as sodium cumene sulfonate, and of sulfuric acid serniesters with C6--C10 alcohols. The hydrotropes need only be used in quantities of up to 5% by weight. 20 Suitable inorganic salts, which may be added in quantities of up to 0.5% by weight, are in particular the sodium or potassium salts of mineral acids. In addition, small quantities of up to 5% by weight of amines or alkali are preferably used for adjusting the pH of the dispersion and for neutralizing the oxidized polyethylene or paraffin waxes or ester waxes containing acidic groups. Alkanolamines, such as diethanolamine, morpholine, sodium or potassium hydroxide are particularly suitable.

The type of agricultural chemicals used in the spray mixtures is not critical to the use of the evaporation inhibitors (EI) according to the invention. For example, the inhibitors may be used for applying the following plant protection agents (the list of which is not intended to limit the invention in any way) Pyrethroids, such as deltamethrin, cypermethrin, fenpropathrin, cyfluthrin, fenvalerate, permethrin; (thio)phosphoric acid esters, such as triazophos, parathionmethyl, dimethoat, heptenophos, pyrazophos, 30 profenofos, sulprofos, dialifos, chlorpyrifos, anilofos; carbarnates, such as BPMC, carbaryl, propoxur, methomyl, carbofuran, phenmedipham, desmedipham, pririmicarb; chlorinated hydrocarbons, such as camphechlor, dicofol; chitin synthesis inhibitors, such as diflubenzuron, trifluron, teflubenzuron (CME 134) or chlorfluazuron (IKI 7899); the agents endosulfan, amitraz, clofentezine, phosethyl AL, prochloraz.

Herbicides of the phenoxy or heteroaryloxy phenoxy propionic acid derivative type, such as diclofop-methyl, fenoxapropethyl, fluazifop-butyl, haloxyfopethoxy-ethyl (Dowco 453), quinofop-ethyl; urea derivatives, such as diuron, isopropturon, linuron, monolinuron, chlortoluron, sulfonyl ureas, such as chlorsulfuron, sulfometuron; triazines such as ametryn, atrazine, simazine; halogenated phenoxy acetic acid or propionic acid derivatives, such as MCPA, dichlorprop, 2,4,5-T, mecoprop, 2,4-D, esters or salts thereof; aniline derivatives, such as butachlor, propanil, benzoylprop- ethyl, alachlor, metolachlor; nitrophenol derivativesl such as binapacryl or dinosebacetat; nitroaniline derivatives, such as trifluralin or pendimethalin; benzothiadiazines, such as bentazone; the agents ioxynil, bromoxynil, metamitron, glufosinate or salts thereof, bialophos or salts thereof, glyphosphate or salts thereof, triazole derivatives, such as triadimefon; the fungicides metal axyl, iprodione, fenarimol, triforine, propiconazol, tridemorph, pyracarbolid; agents containing heavy metals, such as maneb, sineb, triphenyl tin compounds, such as 45 fentin-acetate orfentin hydroxide, azocyclotin, cyhexatin, copperoxy chloride; plant growth regulators, such as mepiquatchloride orchlormequatchloride or similar salts, ancymidol, tetcyclasis or mefluidid.

Further information on these treatment agents may be found in CH. R. Worthing, S. B. Walker, The Pesticide Manual, 7th Ed., British Crop Protection Council, London, 1985.

1. Formulation Examples for Evaporation Inhibitors (Ell All quantities in percent by weight.

Dp.=dropping point (as determined by DGF method 1113) Sp.=setting point (as determined by DGF method III 4a) A No.=acid number (as determined by DGF method IV 2) Br.=boiling range EO=ethylene oxide PO=propylene oxide.

Examples of Composition X EXAMPLE 1

30.0% paraffin, 13p. 50-52'C 2.0% C,27-Cl. fatty alcohol+2 EO 6.0% C16-Cls fatty alcohol+6 EO 2.0% C167-Cla fatty alcohoi+12 EO 60.0% water GB 2 166 974 A 5 EXAMPLE 2

26.0% paraffin, Dp. 50-52T 4.0% white spirit, Br. 180-21 OT 2.0% C127-Cl. fatty alcohol+2 EO 8.0% tallow fatty alcohol+6 EO 2.0% tallowfatty alcohol+12 EO 58.0% water EXAMPLE3

EXAMPLE 5

EXAMPLE6

EXAMPLE 7

EXAMPLE 8

23.0% paraffin, Dp. 50-52T 2.0% paraffin, Dp. 38-400C 10.0% white spirit, Br. 145-200T 6.0% tallow fatty alcohol+6 EO 4.0% C127-Cl. fatty alcohol+4 EO 1.0% tallowfatty alcohol+25 EO 54.0% water EXAMPLE 4.

40% paraffin, Dp. 40-42T 8% oleyllcetyl alcohol+5 EO 52% water 30.0% paraffin, Dp. 38-400C 55.0% xylene 10.5% dodecylbenzene sulfonate, Ca salt (70%) 4.5% CB--Clo 1Clg-C18 fatty alcohol mixture+2 PO+1 1 EO 30.0% paraffin, Dp. 40-42T 55.0% xylene 7.5% petroleum sulfonate, Na salt 7.5% oleic acid+ 15 EO 20.0% paraffin, 13p. 38-40T 65.0% white spirit, Br. 145-200T 7.5% dodecylbenzene sulfonate, Ca salt (70%) 7.5% oleic acid+8 EO 15% microwax, Dp. 68-720C 15% paraffin, Dp. 50-520C 2% Cl-Cls fatty alcohol+2 EO 6% C12-Cl. fatty alcohol+6 EO 40 2% C127-C1,3 fatty alcohol+ 1 2 EO 60% water EXAMPLE 9

15% paraffin, Dp, 57-600C 15% paraffin, Dp. 50-52T 2% C12-Cls fatty alcohol+2 EO 6% C,2-C,8 fatty alcohol+6 EO 2% C, 2-Cl. fatty alcohol+ 12 EO 60% water EXAMPLE 10

30% paraffin, Dp. 50-52T 3% Cl-C14 fatty alcohol+2 EO 5% tallow alcohol+6 EO 3% tallow alcohol+12 EO 3% sodium fatty alcohol ether phosphate (C127-C18+10 EO phosphate, 30%) 56% water 6 GB 2 166 974 A 6 EXAMPLE 11

25.0% paraffin, Dp. 57-600C 3.0% technical oley] alcohol+2 EO 5.0% tallow alcohol+6 EO 2.0% tallow alcohol+12 EO 0.1 % NaCI 64.9% water EXAMPLE 12

30% paraffin, Dp- 50-52'C 3% Clg--Cl, fatty alcohol +2 EO 5% tallow alcohol+6 EO 3% tallow alcohol+12 EO 1 % sodium fatty alcohol sulfate (Cc-Clo sulfate, 30%) 2% sodium cumene sulfonate, 50% 56% water Examples of Composition Y EXAMPLE 13 (Type: Wax Mixture (A)) 20.0% paraffin wax. Sp. 50 to WC 10.0% oxidized polyethylene wax, Dp. 100 to 105'C, A No. 23 to 28 0.5% diethanolamine 2.0% Cjg-Cj8 coconut oil fatty alcohol+2 EO 6.0% tallow fatty alcohol+6 EO 2.0% tallow fatty alcohol+1 2 EO 59.5% deionized water.

EXAMPLE 14 (Type: Wax Mixture W) 27.0% paraffin wax, Sp. 50 to 540C 3.0% oxidized polyethylene wax, Dp. 108 to 11 VC, A No. 20 to 30 0.1% diethanolamine 2.0% Cjg-Cj. coconut oil fatty alcohol+2 EO 30 6.0% tallow fatty alcohol+6 EO 2.0% tallowfatty alcohol+12 EO 59.9% deionized water.

EXAMPLE 15 (Type: Wax Mixture (M) 25.0% paraffin wax, Sp. 50 to 54T 2.5% oxidized polyethylene wax, Dp. 100 to 105'C, A No. 23 to 28 35 2.5% oleyl alcohol (iodine number 50-55)+2 EO 4.2% tallow fatty alcohol+6 EO 2.5% tallow fatty alcohol+1 2 EO 0.1% diethanolamine 2.0% sodium cumene sulfonate (40%) 40 2.7% octanol/decanol sulfate, sodium salt 58.5% deionized water.

EXAMPLE 16 (Type: Wax Mixture (B)) 27.0% paraffin wax, Sp. 50 to 53T 3.0% ester wax (montan wax), Dp. 82 to 88T A No. 25 to 35 0.1 % diethanolamine 2.0% C1r-C18 coconut oil fatty alcohol +2 EO 6.0% tallow fatty alcohol+6 EO 2.0% tallow fatty alcohol + 12 EO 59.9% deionized water.

EXAMPLE 17 (Type: Wax Mixture (Q 14.0% paraffin wax, Sp. 30 to 35T 16.0% oxidized paraffin wax, Sp. 65 to 700C, A No. 30 to 35 3.5% diethanolamine 2.0% C127-Cla coconut oil fatty alcohol+2 EO 6.0% tallow fatty alcohol+6 EO 2.0% tallow fatty alcohol+1 2 EO 56.5% deionized water.

7 GB 2 166 974 A 7 EXAMPLE 18 (Type: Wax Mixture W) 25.0% paraffin wax, Sp. 50 to 520C 2.5% oxidized polyethylene wax, Dp. 108 to 11 I'C, A No. 20 to 30 2.5% oleyl alcohol+2 EO 4.2% tallow alcohol+6 EO 2.5% tallow alcohol+12 EO 0.1% diethanolamine 2.0% C1r_C18 alkane sulfonate, Na salt, 60% 1.5% sodium cumene sulfonate, 40% 0.2% preservative 10 59.7% water.

EXAMPLE 19 (Type: Wax Mixture (A)) 27.0% paraffin wax, Sp. 50 to 54oC 3.0% oxidized polyethylene wax, Dp. 108 to 11 10C, A No. 20 to 30 10.0% dodecyl benzene sulfonate, Ca salt, 70% in xylene 5.0% nonionic surfactant of Cg-Clo /C,6--Cl, fatty alcohol mixture+2 PO+ 11 EO 55.0% xylene.

11. Production of the Evaporation Inhibitors a) Production of the E] of Example 6 In a stirrer-equipped 460 1-vessel, 75 kg of paraffin wax (Dp. 40-42'C, in flake form), 18.75 kg of Na 20 petroleum sulfonate and 18.75 kg of oleic acid+l 5 EO were successively added with stirring to 137.4 kg of xylene. The mixture was stirred for 30 mins. at room temperature, a homogeneous solution being formed.

b) Production of the E] of Example 1 A melt was prepared from 54 kg of paraffin (13p. 50-52'C), 3.6 kg of C127- C1,3 fatty alcohol+2 EO, 10.8 kg of C16-C18 fatty alcohol +6 EO and 3.6 kg of C16-Cl, fatty alcohol+ 12 EO by heating to 60'C. 108 kg of water 25 at 60'C were then introduced into this melt over a period of 15 minutes with stirring. After the addition, the dispersion was cooled to below 30'C over a period of 3 hours.

Ill. Measurement on Evaporating Water Droplets Water droplets 50 to 100 microns in diameter were sprayed onto 12 micron diameter Perlon fibers and photographed at short intervals under a microscope (500x magnification) in order to record their evaporation behavior at laboratory temperature (22'C). The diameter and volume of the droplets after various evaporation times were calculated from the micrographs.

Water and a 2.5% aqueous dilution of the evaporation inhibitor of Example 1 were compared with one another.

Under the microscope, a water droplet approx. 70 microns in diameter evaporated completely after 13 35 seconds at room temperature. After the same time, a droplet of the same diameter containing 2.5% of evaporation inhibitor according to the invention has lost only about one quarter of its original volume through evaporation.

Thetimes afterwhich the droplets had shrunkto half their original volume or half their original diameter, as determined by linear interpolation between the microscope evaluation dots, are listed in Table 40 1.

TABLE 1 Measurement of Evaporation on Droplets Initial Evaporation Time to Diameter Half Initial Volume Half Initial Diameter 45 Water without 67 Microns 5 Seconds 10 Seconds inhibitor Water 64 Microns 18 Seconds 70 Seconds containing 2.5% of Inhibitor 50 IV. Testing the Evaporation-inhibiting Effect Directly on Droplets of the Test Mixtures Hemispherical droplets with a volume of approx. 0.01 pl were formed at the tip of a 1 VI Hamilton syringe arranged horizontally under a microscope by carefully pushing in the plunger. In order to measure evaporation, the size of the droplets was measured after certain time intervals using a graduated scale incorporated in the eyepiece and the droplet volume calculated therefrom. The tests were carried out at 55 230C/55% relative air humidity.

8 GB 2 166 974 A 8 The three spray mixtures tested contained 10% byweightof Hostaquick(R), HOECHSTAG (which contains the insecticide 6 -chlorobicyclo(3,2,0)hepta -2, 6 -dien -6 - V] di methyl phosphate, emulsifiers and xylene), the inhibitor of Example 15 and standard water having a hardness of 342 ppm. The test results are shown in Table 2 below in the form of average values from five tests.

TABLE 2 5

Inhibitor Droplet Volume in 111000 111 After Seconds Content 0 20 40 60 80 100 120 140 0% 11 2.8 0.0 2.5% 11 5.3 3.2 2.1 1.3 0.5 0.0- 5% 11 7.0 6.1 5.4 4.6 3.9 3.1 2.4 10 Water 11 2.0 0.0 - - - - V. Comparative Testing of E[ Using Test Mixtures Free From Active Substances (AS) The following test mixtures were used for testing evaporation inhibition and foaming behavior:

EC-type A:

10g of AS-free concentrate of 8 g of xyiene and 2 g of emulsifier mixture(1.2 9 of nonylphenol+15 EO, 15 0.8 g of dodecylbenzene sulfonate, Ca salt, 70%) were emulsified in 80g of water, followed by the addition of quantitied of 10g of the inhibitors of Examples 1, 2,3,4,89,13,14,15,16 and 17 (Blank value: 10 9 of concentrate without inhibitor in 90 9 of water) EC-type B:

10g of AS-free concentrate of 8 g of phthalic acid diisooctyl ester and 2 g of emulsifier mixture (1.6 g of castor oil+12 EO, 0.4 9 of dodecylbenzene sulfonate, Ca salt, 70%) were emulsified in 80 9 of water, followed by the addition of quantities of 10g of the inhibitors of Examples 5,6 and 7. 25 (Bland value: 10 9 of concentrate without inhibitor in 90 g of water).

WP-type:

5g of AS4ree wettable powder of 4.4 g of kaolin (bolus alba la, ground) and 0.6 g of emulsifier mixture (C127_C14 fatty alcohol sulfate, Na salt, inorganic salts) were suspended in 85g of water, followed by the addition of quantities of 10g of the inhibitors of Examples 1, 2,3,5,6 and 7.

(Blank value: 5 g of powder without inhibitor in 95 g of water).

To test the inhibition of evaporation, quantities of 50 9 of the spray mixtures were introduced into a plane-bottomed glass dish (diameter 120 mm, height 20 mm) and, by weighing out, the evaporation produced by a steady stream of air was determined as a function of time and temperature. The results are shown inTabies3to7.

TABLE 3

Evaporation Loss in % by Weight at 20"C Spray Mixture EC-type A 0.5 h 1 h 2 h 3 h 4 h Blank Value 10 17 31 45 57 40 Example 1 0.4 0.4 0.4 0.4 0.5 Example 8 0.8 1.5 2.9 5.0 6.0 Example 9 0.6 0.6 0.6 0.7 0.8 9 GB 2 166 974 A 9 TABLE 4

Evaporation Loss in % by Weight Test Mixture at 250C EC-type A 112 h 1 h 2 h 3 h 4 h 24 h Blank Value 9.5 15.9 27.0 37.5 48.3 97.9 5 Example 1 0.4 0.4 0.4 0.4 0.5 0.9 Example 2 6.8 10.8 16.1 17.3 17.7 19.1 Example 3 0.1 0.1 0.1 0.2 0.3 1.2 Example 14 0.5 0.5 0.5 0.8 1.0 2.7 Example 15 0.7 0.8 1.0 1.1 1.3 3.1 10 Example 16 0.6 0.9 1.4 1.5 1.9 3.9 TABLE 5 Evaporation Loss in % by Weight Test Mixture at 500C EC-type A 112 h 1 h 1.5 h 2 h 2.5 h 3 h 15 Blank Value 37 71 92 - - - Example 1 20 36 48 53 58 62 Example 8 9 16 20 24 27 29 Example 9 14 24 31 37 40 42 Example 13 17 19 21 23 24 25 20 Example 14 5 7 10 13 15 17 Example 15 6 9 12 15 21 26 Example 16 11 16 20 24 27 30 Example 17 9 17 22 25 29 35 TABLE 6 25

Evaporation Loss in % by Weight Test Mixture at 25'C EC-type B 112 h 1 h 2 h 3 h 4 h Blank Value 9.9 15.9 29.9 42.6 64.9 Example 5 0.1 0.1 0.1 0.1 0.2 30 Example 6 0.2 0.3 0.5 0.8 1.0 Example 7 0.3 0.8 1.3 1.6 1.9 GB 2 166 974 A 10 TABLE 7 Evaporation Loss in % by Weight Test Mixture at 25% WP-type 112 h 1 h 2 h 3 h 4 h 5 h Blank Value 5.9 10.6 20.2 31.2 41.8 95.0 5 Example 1 3.8 5.5 8.6 11.7 15.3 59.5 Example 2 1.1 2.2 4.3 6.6 9.2 44.2 Example 3 6.7 7.6 8.6 9.5 10.4 21.9 Example 5 0.2 0.3 0.4 0.5 0.6 Example 6 0.7 0.9 1.5 1.8 2.0 - 10 Example 7 0.6 0.8 0.8 0.9 0.9 - VI. Testing of Foaming Behavior To testfoaming behavior, the spray mixtures were tested and evaluated bythe perforated-disc beating method (DIN 53902). The results are shown in Table 8.

TABLE 8 (Working Conditions: Volume 200 ml, No. of Strokes 30, Temperature 250C) Foam Volume in mi Spray Mixture Time (Minutes) EC-type A 0.5 2 10 30120 180 Blank Value 100 80 40 30 10 - 20 Example 1 0 - - - - - Example 2 5 0 - - - - Example 4 0 - - - - - Spray Mixture WP-type 25 Blank Value 580 570 550 540 540 540 Example 1 70 50 50 40 30 30 Example 2 0 - - - - Example 3 10 10 10 10 5 5 V11. Comparative Testing of El Using Commercial Products a) Using the same methods as in Section V, comparative tests were carried out with spray mixtures prepared from commercial concentrates.

The EC used was the insecticide concentrate, Hostaquick@ (a product of Hoechst), which contains 6 chlorobicyclo - (3,2,0) - hepta - 2,6 - then 6 - yl dimethyl phosphate as its active constituent. The WP used was the fungicide spraying powder, Derosal@ (a product of Hoechst), containing 2 (methoxycarbonylamino) - benzimidazole as its active constituent. Table 9 shows the results of the evaporation tests at 25'C.

11 GB 2 166 974 A 11 Spray Mixture of Hostaquick@ (EC 50) Blank Value Example 1

Derosal@ (WP 60) Blank Value Example 6

TABLE 9

112 h 1 h 2 h 3 h 4 h 24 h 6.3 10.3 20.3 0.6 0.8 0.9 8.1 19.5 29.0 0.1 0.1 0.1 33.7 41.7 1.1 1.2 5.1 45.8 67.6 95.0 0.1 0.2 0.7 b) Further Tests were Carried out as Follows Using a Thermobalance 10% test mixtures were prepared from three standard commercial plant protection agent concentrates. The inhibitor (E1) of Example 15 was then added to the test mixtures in quantities of 0%, 5% and 10%.

To measure evaporation behavior, quantities of 50 lil of these spray mixtures were introduced into a cylindrical aluminium dish (diameter 6.5 mm, height 1.5 mm). The evaporation as a function of time produced by a steady stream of air (40 1/h) at 50'C was measured by means of a thermobalance (Du Pont 15 Model TGA 951), the weight of the sample being continuously recorded by a recorder. The results are shown in Table 10 below:

TABLE 10

Active Inhibitor Weight of the Sample in mg Substance (% by After Mins. 20 Concentrate Weight) 0 30 60 90 120 150 Hostathion(E) 0% 50 8 3 3 3 3 5% 50 41 35 30 25 20 10% 50 43 41 40 39 38 Afugan@ 0% 50 9 2 2 2 2 25 5% 50 41 35 30 26 23 10% 50 42 40 38 37 36 liloxan(E) 0% 50 9 3 3 3 3 - 5% 50 40 36 31 26 21 10% 50 41 36 32 29 26 30 Water 0% 50 10 0 0 0 0 Hostathion@ (HOECHSTAG) contains the insecticide 1 -phenyl -3 -(0,0 diethylthionophosphoryl) -1,2,4 -triazole, emulsifiers and xylene.

Afugan@ (HOECHSTAG) contains the fungicide 2 -(0,0 diethyithionophosphoryi) -5 -methyl -6 - carbethoxy -pyrazolo -(1,5 -a) pyrimidine, emulsifiers and xylene.

Illoxan@ (HOECHSTAG) contains the herbicide 2 -(4 -(2',4' dichlorophenoxy) -phenoxy) propionic acid methylester, emulsifiers, xylene and cyclohexanone.

c) In the same way as in b), tests were carried out with a thermobalance at 500C on the variously concentrated spray mixtures listed in Table 11 to which an El corresponding to Example 1 had been added.

Evaluation was based on the average evaporation rate.

To calculate this value, the times required to evaporate half the respective sample volumes were taken from the graphs. The volume evaporated divided by the time, based on one square centimeter of evaporation surface, is shown as the average evaporation rate in Table 11. For simplification, the curvature of the evaporation surface was not taken into account in the calculation.

The magnitude of the evaporation-inhibiting effect depends to a large extent on the type and concentration of the surfactants in the spray mixture. The fact that the various plant protection agents introduce varying amounts of various surfactants into the spray mixture accounts for the differences in the evaporation-inhibiting effect.

12 GB 2 166 974 A 12 TABLE 11 Concentrations Product Inhibitor Commercial Product Evaporation Rate mglmin. per CM2 Water 100 0 4.2 5 10 0.8 Endosulfan 35 EC 10 0 4.5 (insecticide) 20 10 1.9 10 0.8 5 2.5 1.5 10 Triazophos 40 EC: 10 0 4.4 (insecticide) 10 10 0.3 5 0.4 2.5 2.5 1.3 5 2.5 0.9 15 Heptenophos 50 EC 10 0 3.6 (insecticide) 10 10 0.1 Diclofopmethyl 36 EC 10 0 4.0 (Herbicide) 10 2.5 0.3 10 1 0.5 20 Pyrazophos 30 EC 10 0 4.4 (Fungicide) 10 10 0.8 Vill. Open-airTest The effect in practice of the reduction in evaporation rate observed in the laboratory was studied in an open-air test under subtropical climatic conditions. The pests Heliothis ssp. and Anthonomus grandis which 25 attack cotton plants were treated at average air temperatures of 38'C and low humidity levels.

The tests were carried out on two identical 3-hectare parcels planted with cotton which had been pretreated with the usual plant protection agents according to the level of infestation. Forthe nextfour applications, the inhibitor of Example 1 was added to the spray mixture applied to parcel 1 whilst parcel 2 was sprayed without any inhibitor.

The following amounts of plant protection agents per hectare were applied in each of the four sprayings:

Parcel 1 0.51 Decis@ (2.5 EQ1) 2.0 1 Thiodan@ (35 EQ') 27.0 1 water 0.51 inhibitor Parcel 2 0.51 Decis@(2.5 EC) 2.0 1 Thiodan(C) (35 EC) 27.5 1 water EC-concentrate@ Decis contains the insecticide (IR:3S). - 3 - (2,2 dibromovinyl) - 2,2 dimethylcyclopropane carboxylic acid (ciS) a - cyano 3 - phenoxybenzyl ester 2) EC-concentrate@ Thiodan contains the insecticide 6,7,8,9,10,10 - hexachloro -1,5,5a,9a tetrahydro -6,9 -methano -2,4,3 -benzodloxathiepin oxide as its active constituent.

The two parcels were then furthertreated in exactly the same way. All applications were made by airplane.

At the end of the spraying season, the yields were determined. Parcel 1 yielded another 200 kg of cotton per hectare, corresponding to an increase in yield of 5% over Parcel 2.,

Claims

1. An evaporation inhibitorfor spray mixtures of agricultural chemicals applied by the LV method in the form of a wax-containing aqueous dispersion or self-emulsifying solution in organic solvents having the following composition:

13 GB

2 166 974 A 13 from 15 to 50% by weight of a wax or wax mixture, from 4 to 20% by weight of nonionic and/or anionic emulsifiers, from 19.5 to 81 % by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points of from 70 to 2800C, from 0 to 5. 5% by weight of other auxiliaries, from 0 to 5,0% by weight of amines or alkali.

from from 2. An evaporation inhibitor as claimed in Claim 1 having the following composition:

from 15 to 40% by weight of a wax mixture containing paraffin waxes and. having a dropping point of from 35 to 80'C, 4 to 20% by weight of nonionic and/or anionic emulsifiers, 35 to 81 % by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points of from 70 to 280'C, from 0 to 5.5% by weight of other auxiliaries.

3. An inhibitor as claimed in Claim 2 in the form of an aqueous dispersion having the following 15 composition:

from from from from 1.5 from 15 to 40% by weight of paraffin waxes or of a mixture of paraffin waxes having different dropping.

points in the range from 35 to 700C or of a mixture of these paraffin waxes with microcrystalline waxes having dropping points in the range from 50 to 90T, the paraffin waxes making up at least 50% by weight of the wax mixture, 4to 20% by weight of nonionic emulsifiers, 0 to 10% by weight of anionic emulsifiers, the nonionic emulsifiers making up at least 50% by weight of the emulsifiers, from 35 to 81 % by weight of water, from 0 to 10% by weight of xylene or cyclohexanone or petroleum fractions having boiling points in the range from 145 to 21 OOC or esters having boiling points in the range from 70 to 280T, 25 from 0 to 5% by weight of hydrotropes, from 0 to 0.5% by weight of inorganic salts.

4. An evaporation inhibitor as claimed in Claim 1 having the following composition:

from 15 to 50% by weight of a wax mixture containing a wax component having an acid number of from 10 to 95 mg KOH/g wax, from 4 to 20% by weight of nonionic and/or anionic emulsifiers, from 19.5 to 81 % by weight of water and/or organic solvents from the group comprising hydrocarbons, esters and ketones having boiling points in the range from 70 to 2800C, 0 to 5.5% by weight of auxiliaries, 0 to 5.0% by weight of amines or alkali.

5. An inhibitor as claimed in Claim 4 in which the wax mixture has one of the following compositions A, B or C:

Mixture (A) from 60 to 95% by weight of paraffin wax and/or microcrystalline paraffin wax having a setting point of from 40 to 70'C, from 5 to 40% by weight of oxidized polyethylene wax having a dropping point of from 95 to 1400C and an acid number of from 10 to 95 mg KOH/g Wax.

Mixture (B) from 60 to 95% by weight of paraffin wax and/or microcrystalline paraffin wax having a setting point of from 40 to 700C, from 5 to 40% by weight of a wax containing ester bonds and having a dropping point of from 75 to 1 OOOC and an acid number of from 10 to 95 mg KOH/g wax.

Mixture (C) from 20 to 50% by weight of paraffin wax having a setting point of from 30 to 50T, from 50 to 80% by weight of oxidized paraffin wax having a setting point of from 60 to 90T and an acid 50 number of from 10 to 95 mg KOH/g wax.

composition:

6. An inhibitor as claimed in Claim 5 in the form of an aqueous dispersion having the following 14 GB 2 166 974 A 14 from 15 to 40% by weight of wax mixture (A), (B) or (C), from 4 to 20% by weight of nonionic emulsifiers, from 0 to 10% by weight of anionic emulsifiers, the nonionic emulsifiers making up at least 50% by weight of the emulsifiers, from 29.5 to 81 % by weight of water, from 0 to 10% by weight of xylene or cyclohexanone or petroleum fractions having boiling points in the range from 145 to 21 OOC or esters having boiling points in the range from 70 to 2800C, from 0 to 5% by weight of hydrotropes, from 0 to 0.5% by weight of inorganic salts, from 0 to 5.0% by weight of amines or alkali.

7. An inhibitor as claimed in any of Claims 1 to 6 containing from 0.5 to 10% by weight of anionic emulsifiers, the nonionic emulsifiers making up at least 50% by weight of the emulsifiers.

8. An inhibitor as claimed in any of Claims 1 to 7 containing from 4 to 14% by weight of nonionic emulsifiers and from 1 to 7% by weight of anionic emulsifiers.

9. An inhibitor as claimed in any of Claims 1 to 8 in which the nonionic emulsifiers are selected from the 15 group comprising sorbitan esters of higher fatty acids, long-chain alkyl glycosides and alkylene oxide adducts with higher, linear, morlohydric and polyhydric alcohols, alkylphenols, long-chain carboxylic acids, carboxylic acid amides and hydroxy fatty acids containing from 10 to 24 carbon atoms, fatty acid glycerol or sorbitan esters or long-chain alkyl glycosides and mixtures thereof.

10. An inhibitor as claimed in any of Claims 1 to 9 in which the nonionic emulsifiers are selected from 20 the group comprising adducts of from 2 to 50 moles of ethylene oxide with long-chain primary alcohols or Clg-Cl, fatty acids and mixtures thereof.

11. An inhibitor as claimed in any of Claims 1 to 10 in the form of an aqueous dispersion in which the nonionic emulsifiers are mixtures of ethylene oxide adducts with C127-Cla fatty alcohols or alkylphenols, consisting of from 10 to 40% by weight of adducts containing from 1 to 4 moles of ethylene oxide, from 25 to 70% by weight of adducts containing from 4 to 10 moles of ethylene oxide and from 5 to 35% by weight of adducts containing from 10 to 50 moles of ethylene oxide.

12. An inhibitor as claimed in any of Claims 1 to 11 in which the anionic emulsifiers are selected from the group comprising salts of sulfuric acid serniesters or phosphoric acid partial esters of linear alcohols or 30 alkylphenols containing from 12 to 18 carbon atoms or polyglycol monoalkylethers containing from 12 to 18 carbon atoms in the alkVI group and olefin sulfonates, ester sulfonates and alkane sulfonates containing from 12 to 20 carbon atoms, alkylbenzene sulfonates containing from 6 to 16 carbon atoms in the alkyl group, sulfonates of polyglycol monoalkVlethers and salts of polyglycol monoalkylether carboxylic acids containing from 12 to 18 carbon atoms in the alkyl chain and mixtures thereof.

13. An inhibitor as claimed in any of Claims 1 to 12 in which the anionic emulsifiers are selected from the group comprising alkVIbenzene sulforlates containing from 6 to 16 carbon atoms in the alkVI groups, alkane sulfonates containing from 12 to 20 carbon atoms and mixtures thereof.

14. A process for reducing the evaporation of water from spray mixtures of agricultural chemicals during application by the LV method, in which from 1 to 15% by weight of the evaporation inhibitor claimed 40 in any of Claims 1 to 13 is added to the spray mixtures adjusted to the in-use concentration.

15'A process as claimed in claim 14 in which from 5 to 10% by weight of the evaporation inhibitor is added to the spray mixture adjusted to in-use concentration.

16. The use of the evaporation inhibitor claimed in any of Claims 1 to 13 for reducing the evaporation of water from spray mixtures containing agricultural chemicals applied by the LV method.

17. A process for producing the evaporation inhibitor in the form of an aqueous dispersion claimed in any of Claims 1 to 13 characterised in that either a) the wax or the wax mixture is melted together with the emulsifiers and, optionally, the organic solvents, after which the water is stirred into the melt, optionally together with the other constituents, and the dispersion subsequently cooled or b) the wax or the wax mixture is melted together with the emulsifiers and, optionally, the organic solvents, the melt is introduced with stirring into the water heated to 60-1000C which optionally contains the other constituents of the inhibitor and the dispersion formed is rapidly cooled.

18. An evaporation inhibitor as claimed in claim 1 substantially as herein described with reference to anyone of the Examples.

19. A process for the preparation of an evaporation inhibitor as claimed in claim 1 substantially as herein described with reference to the Examples.

20. A method as claimed in claim 15 for reducing the evaporation of water from spray mixtures containing agricultural chemicals substantially as herein described with reference to the Examples.

Printed for Her Majesty's Stationery Office by Courier Press, Leamington Spa. 5/1986. Demand No. 8817356.

Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.

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