<div class="application article clearfix" id="description">
<p class="printTableText" lang="en">New Zealand Paient Spedficaiion for Paient Number £05688 <br><br>
205688 <br><br>
. Pc.artty OcrtetAS <br><br>
\ Compete SI <br><br>
\a^j ;;;;:;. <br><br>
\ publication 0°^ <br><br>
\ P.O. — <br><br>
N.Z.No. <br><br>
NEW ZEALAND <br><br>
Patents Act 1953 <br><br>
HO DRAWINGS <br><br>
COMPLETE SPECIFICATION <br><br>
"MICROEMULSIONS" <br><br>
We, BAYER AKTIENGESELLSCHAFT, a Company registered under the laws of the Federal Republic of Germany, of Leverkusen, Germany do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : - <br><br>
- 1 - <br><br>
(followed by 1A) <br><br>
205688 <br><br>
- ifl-- <br><br>
The present invention relates to aqueous micro-emulsions of agrochemical active compounds, active compounds for combating pests in the domestic and hygiene sectors, and/or pharmacologically active substances. The 5 invention also relates to a process for the preparation of these microemulsions and to their use. <br><br>
-S <br><br>
Oil-in-water emulsions of numerous agrochemical active compounds of low solubility in water are already known; in addition to the active compounds, these 10 emulsions also contain, in each case, either a surface-active substance and a thickener or else a relatively large quantity of surface-active substances (compare U.S. Patent No 4,303,604}. This addition of thickeners or of large quantities of surfactant is associated with additional expense and thus constitutes a serious disadvantage of the known oil-in-water emulsions. In addition to this, the preparation which 20 has hitherto been described of emulsions of this type is not generally applicable. This is because, essentially, it is possible to emulsify by this process only those active compounds of low solubility in water which are liquid at room temperature or at least have a very low 25 melting point. It is also disadvantageous that the known oil-in-water emulsions are frequently not adequately stable under cold conditions and that, in some cases, forced emulsification using homogenisers is required. Aqueous microemuIsions which contain 0.1 to 80% by weight of at least one agrochemical active compound of low solubility in water, one active compound for combating pests in the household and hygiene sectors of lew solubility in water and/or one pharmacologically active corrpound of low solubility in water, <br><br>
30 - <br><br>
2 0 5 6 8 8 <br><br>
- 2 - <br><br>
1 to 20% by weight of a mixture of emuLsifiers consisting of a) at least one alkylaryl polyglycol ether of the fo rmu la <br><br>
-0-(X)m-(Y)n-H <br><br>
(I) <br><br>
irt which <br><br>
R represents alkyl having 8 to 20 carbon atoms, <br><br>
X and Y each represent a -C^-CH^'O"/ -CHo-CH-0- or -CH-Cgroup, but X and Y <br><br>
i t ch3 CH3 <br><br>
do not simultaneously represent an oxyethylene or oxypropylene unit, <br><br>
m represents numbers from 10 to 45 and n represents numbers from 10 to 45, and at least one a Iky lary Isu Iphonic acid salt of the fo rmu la <br><br>
_1 © © (II) <br><br>
~S03 Me in which <br><br>
R^ represents alkyl having 8 to 35 carbon atoms and <br><br>
Me^7 represents an alkali metal cation, an equivalent of an a I k a I i ne* e a r t h metal cation or a cation of the formula ;R" ;. © ;R' ~ N - r"' ;RIV ;wherein ;R', R", R"1 and R1^ independently of one ;205688 ;another represent hydrogen, alkyl having 1 to 4 carbon atoms or hydroxyalkyl having 1 to 4 carbon atoms, or b) at least one alkylaryl polyglycol ether of the formula ;0-(CH2-CH2-0)--H (III) ;p ;(CH, ) ;in which p represents numbers from 5 to 20 and q represents numbers from 1 to 3, and ;10 at Least one a Iky LaryIsuLphonic acid salt of the formula ;R±^Vso3 9 (ii> ;in which and have the meaning indicated ;15 above, ;and also water and if appropriate, 1 to 30% by weight of at Least one organic solvent of low miscibility with water and/or of a soLubiliser and also, 20 - if appropriate, 0.05 to 15% by weight of additives, ;the sum of the components being in each case 100% by weight, have been found. ;It has also been found that the microemuLsions according to the invention can be prepared by adding, while 25 stirring, to water optionally containing additives, a homogeneous mixture consisting of at least one agrochemical active compound of low solubility in water, one active compound for combating pests in the household and hygiene ;205688 ;sectors of low solubility in water and/or one pharmacologically active oonpound of low solubility in water, ;a mixture of emuLsifiers consisting of a) at Least one alkylaryl polyglycol ether of the formula ;-O-(X) -(Y) -H ;m n ;(I) ;10 ;in which ;R, X, Y, m and n have the meaning indicated above, and at Least one alkylaryLsulphonic acid salt of the formula ;e ;Me ;(II) ;15 ;in whi ch ;R^ and Me® have the meaning indicated above, or b) at Least one alkylaryl polyglycol ether of the formula ;0-(ch -ch,-0) h ;(ch. ;(Ill) ;) ;20 ;in which p and q have the meaning indicated above, and at Least one aLkylarylsulphonic acid salt of the fo rmu I a ;R1- ;)>-so22 ;© ;(II) ;Me. ;ft ;A' ;r r y» " "VI© ;-'W ;t ;-\\ ,«p "'if l l w b ;- 5 - ;205688 ;in which ;1 (?) ;R1 and Mew have the meaning indicated above, ;- if appropriate, at Least one organic solvent of low miscibility with water and/or a solubiliser, ;5 and also, ;- if appropriate, additives. ;Finally, it has been found that - depending on the active compounds they contain - the microemuIsions according to the invention can be used for various pur-10 poses in agriculture or horticulture, in the household and hygiene sectors or in the medicinal sector. ;It must be described as extremely surprising that the microemuIsions•according to the invention are stable, since it would have been expected on the basis of the 15 known state of the art that emulsions of this type, which contain no thickeners and also only a small proportion of surfactant, would not be stable for a pro longed^period. Thus it is apparent frcm U.S. Patent No 4,303,640 that the oil- ;-in-water emulsions described in those texts necessarily contain a thickener as a stabiliser. Sane known emulsions have a very high proportion of surfactant in relation to the quantity of active com-25 pound. The excellent stability of the microemu Isions according to the invention could not, therefore, have been foreseen. ;The microemuIsions according to the invention are distinguished by a number of advantages. Thus the expen-30 sive addition of thickeners or Large quantities of emuLsifiers is not necessary in their preparation. Furthermore, these emulsions contain either only an extremely small quantity of organic solvents or none at all. Therefore, they are incombustible and free, or at Least virtually 35 free, from odour troubles caused by organic solvents, and have a lower toxicity or phytotoxicity than corresponding ;2056 88 ;- 6 - ;formulations containing organic solvents in the concentrations otherwise customary. In addition, the micro-emulsions according to the invention are stable under the conditions which prevail in practice. When stored for 5 long periods, these emulsions remain unchanged both at temperatures of 50°C and at low temperatures. Finally, the microemu I sions according to the invention can be prepared in a simple manner. Forced emu Isification using homogenisers is not necessary. In addition, a very con-10 siderable advantage consists in the fact that active compounds of low solubility in water which are solid or liquid at room temperature can be emulsified with equal ease. Furthermore, the microemu I sions according to the invention have a relatively low viscosity, so that accurate metering 15 presents no difficulties. Finally, the microemu Isions according to the invention are completely transparent preparations which can be diluted without problems in any desired ratio with water before use, stable, sprayable formulations being thus formed. ;20 The microemu I sions according to the invention con tain at least one agrochemical active compound of low solubility in water, one active compound for combating pests in the household and hygiene sectors and/or one pharmacologically active compound. These active compounds 25 are present in the liquid state in the oil phase. ;Suitable active compounds are substances which are liquid at room temperature, as well as those which are solid at room temperature. The only requirement for liquid active compounds is that they should be sparingly 30 soluble in water. Compounds of this type are to be under^ stood here as meaning substances which are soluble to the extent of not more than 0.5% by weight in water at 20°C. Solid active compounds must, however, additionally be adequately soluble in an organic solvent of low misci-35 bility with water and/or in a solubiliser. ;Agrochemical substances are to be understood in ;2 0 5 6 8 ^ ;- 7 - ;the present case as meaning any active compounds which can customarily be used in plant protection. These include, for example, insecticides, acaricides, nematocides, fungicides, herbicides, growth regulators and fertilisers. The 5 following may be mentioned as individual examples of active compounds of this type: ;0,0-diethyl 0-(4-nitropheny I) thionophosphate, ;0,0-dimethyl 0-(4-nitropheny I) thionophosphate, ;O-(ethyl) 0-(4-methylthiophenyl) S-propyl dithiophosphate, 10 (0,0-diethylthionophosphoryl) -C(- oximinophenyLacetonitri le, ;2-isopropoxyphenyl N-methylcarbamate, ;3-methylthio-4-amino-6-tert.-butyl-1,2,4-triazin-5-one, ;3-methylthio-4-isobutylideneamino-6-tert.-butyl-1,2,4-t ri azin-5-one, ;15 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine, 2,3-di hydro-2,2-dimethyl-7-benzofuranyl methylcarbamate, 3,5-dimethyl-4-methylthiophenyl N-methyl carbamate, ;0,0-diethyl 0-(3-chIoro-4-methyl-7-coumarinyI) thiophos-phate, ;20 6,7,8,9,10,10-hexach Loro-1,5,5A,6,9,9A-hexahydro-6,9-methane-2,3,4-benzodioxathiepin-3-oxide, 1,4,5,6,7,8,8-heptachloro-4,7-endomethylene-3A,4,7,7A-tetrahydroindene, ;2-(2-furyl)-benzimidazoLe, 25 5-amino-1-bis-(dimethylamido)-phosphoryl-3-phenyl-1,2,4-t ri azole, ;4-hydroxy-3-(1,2,3,4-tetrahydro-1-naphthyl)-coumarin, ;5-C1,2-bis-Cethoxycarbonyl)-ethyl3 0,0-dimethyl dithiophosphate, ;30 0,0-dimethyl 0-(4-methy I mercapto-3-methy1phenyI) thionophosphate, ;0-ethyl-0-(2-isopropoxycarbonylphenyl)-N-isopropylthiono-phosphoric acid ester-amide, ;1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)-35 2-butanone, ;( S) -C(-cy ano-3-ph enoxybenzy I (1 R)-c i s-3-<2 ,2-di b r omo vi ny I) - ;2056 88 ;- 8 - ;2,2-dimethylcyc LopropanecarboxyLate and ;<X-cy ano-3-ph eno xy-4-f luorobenzyL 2,2-dimethyl-3-(/?, /?- ;dichlorovinyU-cyclopropanecarboxylate. ;Active compounds for combating pests in the 5 domestic and hygiene sectors are to be understood, in the present case, as meaning any customary active compounds of Low soLubiLity in water which are suitable for indications of this type. The foLLowing may be mentioned as individual examples of active compounds of this type: 10 2-isopropoxyphenyl N-methylcarbamate, ;0,0-diethyl 0-(4-nitrophenyl) thionophosphate, ;0,0-dimethyl 0-(4-nitrophenyl) thionophosphate, S-C1,2-bis-(ethoxycarbony I)-ethy 13 0,0-dimethyl dithio-phosphate, ;15 0,0-dimethyl 0-<3-methyL-4-nitrophenyI) thionophosphate, 0,0-dimethyl 0-(4-methyI mercapto-3-methyLpheny I) thionophosphate, ;5-hexachlorocyclohexane and ;(cyclohex-1-ene-1,2-dicarboximidomethyl) 2,2-dimethyl-3-20 (2-methyLpropenyl)-cyclopropanecarboxylate. ;Pharmacologically active substances are to be under stood in the present case as meaning substances of low solu bility in water which can preferably be employed in the field of veterinary medicine. The following may be men-25 tioned as an example of active compounds of this type: ;o(- cy a no-3-ph eno xy-4-fluorobenzyl 2,2-dimethyl-3-C^-(p-chlorophenyl)-£-chlorovinyl3-cyclopropanecarboxylate. ;The emulsifier mixtures present in the microemul-sions according to the invention consist of either at 30 least one alkylaryl polyglycol ether of the formula (I) ;and at least one a IkyI aryLsu Iphonic acid salt of the formula (II), or at least one alkylaryl polyglycol ether of the formula (III) and at least one a I ky I ary I su Iphonic acid salt of the formula (II). ;35 The alkylaryl polyglycol ethers of the formula ;(I) are defined in a general manner by the formula ;205688 ;indicated. In this formula, R preferably represents alkyl having 10 to 18 carbon atoms. X and Y each represent a -CHo-CH-p-0-, -CH-j-CH-0- or -CH-C H->-0- group, but ;C £. i , ;ch3 ch3 ;X and Y do not simultaneously represent an oxyethylene or 5 oxypropyLene unit. The index jn preferably represents numbers from 12 to 30 and the index preferably represents numbers from 12 to 40. The numbers for the indices £ and n represent average values. ;The emuLsifiers of this type which are used in 10 practice are generally mixtures composed of several compounds of the formula (I). In particular, they are mixtures composed of substances of the formula (I), differing in the number of oxyethylene and/or oxypropyLene units. Calculation thus also yields fractional numbers as 15 average values for the indices £ and ru Substances for which the following average compositions result may be mentioned as examples: ;C9H19 ;-O (CH2-CHO) (CH2-CH20) 2"Q H CH, ;G 9 H1 9 ;-o (CH-CH20) (CH2-CH20)jj- ;CH_ 27,5 ;H ;C9H1 9 ;0"(CH2"<7HO) 24—(CH2"CH20) 36~ H CH„ ;205688 ;- 10 - ;C9H1 9 ;jp)\o- (CH2-CH-0)I1-(CH2-CH20) 4Q-H ;CH. ;C9H19 ;O-(CH-CH20) 27 ^ (CH2-CH20)-jg—H CH_ ;C9H19 ;-0- (CH2-CH20) 2^-(CH2-CHO) ;CH-. ;The alkylaryl polyglycol ethers of the formula (I) 5 are known. ;The a Iky I ary I su Iphonic acid salts present in the microemulsiqns according to the invention are defined in a general manner by the formula (II). In this formula, ;A ;R preferably represents straight-chain or branched 10 alkyl having 9 to 30 carbon atoms. Me® preferably represents a sodium cation, one equivalent of a calcium cation or a cation of the formula ;R" ;f r> - N - R" ' ;RIV ;wherein ;15 R', R", R'" and RIV independently of one another preferably represent hydrogen, alkyl having 1 or 2 carbon atoms or hydroxyalkyl having 1 to 2 ca rbon atoms . ;The following may be mentioned as individual 20 examples of a IkyI ary I su lphonic acid salts of the formula (II) : ;205688 ;11 ;sodium 4-(n-nonyl)-phenylsulphonate, ;calcium 4-(n-dodecyl)-phenylsulphonate, ;sodium 4-(tetrapropylene)-phenylsulphonate, ;calcium 4-(n-nonyl)-phenylsulphonate, ;5 ammonium 4-(i-dodecy I)-pheny I su I phonate and ;(2-hydroxyethyl)-ammonium 4-(n-dodecyl)-phenylsulphonate. ;(II) are known. They are generally employed in the form of 50-75% strength solutions in organic solvents, for 10 example n-butanol, i-butanol or benzyl alcohol, but can, in principle, also be used without a solvent. ;(Ill) are defined in a general manner by the formula indicated. In this formula, the index p preferably represents 15 numbers from 8 to 18, and the index q preferably represents numbers from 1 to 2. The numbers for the indices p and q represent average values. ;practice are generally mixtures composed of several com-20 pounds of the formula (III). In particular they are mixtures composed of substances of the formula (III), differing in the number of oxyethylene units and/or in the degree of substitution on the phenyl radical. Calculation can thus also yield fractional numbers as average values 25 for the indices p and q. Substances for which the following average compositions result may be mentioned as e x a mp I e s : ;The a Ikylary1su lphonic acid salts of the formula ;The alkylaryl polyglycol ethers of the formula ;The emuLsifiers of this type which are used in and ;205688 ;- 12 - ;<CH2\U/ >1,7 ;0-(CH2-CH2-0)12-H ;The alkylaryl polyglycol ethers of the formula (III) are also known. ;Any customary organic solvents of low miscibility 5 with water.are suitable as the organic solvents which can, if appropriate, be present in the microemuIsions according to the invention. Solvents which may be mentioned preferentially are aromatic hydrocarbons, such as xylene, toluene and dimethy lnaphtha lene, and also chlorinated 10 aromatic hydrocarbons, such as ch lorobenzenes, and also aliphatic hydrocarbons, such ligroin and petroleum ether, additionally halogenated aliphatic hydrocarbons, such as methylene chloride and chloroform, additionally cyclo-aliphatic hydrocarbons, such as cyclohexane, and also 15 alcohols and ketones, such as n-butanol, n-hexanol, iso-hexanol, n-octanol, eye Lohexanol, benzyl alcohol, di-n-butyl ketone and isophorone, and also ethers and esters, such as glycol monomethyl ether and glycol monomethyl ether-acetate., and, furthermore, also triethyl phosphate. 20 Any customary solubilisers are suitable as the solubilisers which can be present in the microemu I sions according to.the invention. Solubilisers which can be used preferentially are alkylphenols or cresols which have been subjected to a condensation reaction with, per mo I, 25 1 to 8 mols of ethylene oxide. p-Cresol which has been subjected to a condensation reaction with, per mo I, 1 to 8 mols of ethylene oxide should be mentioned specially in this connection. ;-Suitable additives which can, if appropriate, be 30 present in the microemulsions according to the invention are preservatives, dyestuffs, cold stabilisers and ;2 0 56 SB ;- 13 - ;synergists. ;2-HydroxybiphenyL and sorbic acid may be mentioned as examples of preservatives. Azo dyestuffs and phthalo-cyanine dyestuffs may be mentioned as examples of dye-5 stuffs. Urea, sugars and salts, such as ammonium sulphate and sodium oleate, may be mentioned as examples of cold stabilisers. 3,4-Methy lenedioxy-6-propyIbenzy l-n-buty I diethyIene glycol ether (piperonyl butoxide) may be mentioned as an example of a synergist. 10 The percentage proportions of the components pre sent in the microemu Isions according to the invention can be varied within specific ranges. In general, the propoi— tion of active compound or active compounds is between 0.1 and 80% by weight, preferably between 5 and 80% by 15 weight. The proportion of emulsifier mixture is, in general, 1 to 20% by weight, preferably 3 to 16% by weight, and the ratio of the emuLsifiers to one another can also be varied within a specific range. In general, there is 0.2 to 1.2, preferably 0.4 to 1, part of emulsifier of the 20 formula (II) to 1 part of emulsifier of the formula (I). Furthermore, there is, in general, 0.1 to 1.2 parts, preferably 0.2 to 1.0 part, of emulsifier of the formula (II) to 1 part of emulsifier of the formula (III). ;Organic solvents of low miscibility with water 25 and/or solubilisers can be present in proportions of 1 ;to 30% by weight, preferably 5 to 20% by weight. Additives can be present in proportions of 0.05 to 15% by weight, preferably 0.1 to 10% by weight. The percentage proportion of water in the microemu I sions according to the 30 invention is in each case the difference between 100% by weight and the total of the percentage proportions of the other components. ;The ratio of active compound(s), on the one hand, optionally mixed with organic solvents and/or solubilisers, 35 to the emusifier mixture on the other hand can be varied within a specific range in the microemuIsions according to ;2 056 8*? <br><br>
- 14 - <br><br>
the invention. In general, there are 1 to 15 parts by weight, preferably 2 to 10 parts by weight, of active com-pound(s), if appropriate mixed with organic solvents and/ or solubilisers, to 1 part of emulsifier mixture. <br><br>
5 In preparing the microemuIsions according to the invention it can be preferable to use all the components which have already been mentioned preferentially in connection with the description of the microemulsions according to the invention. <br><br>
10 If an active compound which is in the liquid state at temperatures up to 40°C is used in the process according to the invention, it is generally unnecessary to add an organic solvent and/or a solubiliser of low miscibility with water. <br><br>
15 If, on the other hand, an active compound which is in the solid state at temperatures up to 40°C is used in the process according to the invention, it is necessary to dissolve the active compound concerned in an organic solvent of low miscibility with water and/or a solubiliser 20 before emu I sification. The quantity of organic solvent and/or solubiliser in this case is such that it is exactly sufficient to dissolve the solid substance. <br><br>
The reaction temperatures in the process according to the invention can be varied within a fairly wide range. 25 In general, the process is carried out at temperatures between 10°C and 80°C, preferably between 20°C and 60°C. <br><br>
The method generally followed in carrying out the process according to the invention is first to prepare a homogeneous solution consisting of one or more active com-30 pounds, an emulsifier mixture, if appropriate an organic solvent of low miscibility with water and/or a solubiliser and, if appropriate, additives, and then to add this mixture, while stirring, to water, if appropriate containing additives. In doing so, the quantities of the components 35 are selected in such a way that the components in the resulting microemulsion are present in the concentration <br><br>
2 0 5 6 P ^ <br><br>
- 15 - <br><br>
desired in the particular case. The sequence in which the components of the organic phase are combined can be varied. The addition of the organic phase to the aqueous phase is advantageously effected slowly, while stirring uniformly 5 with customary stirring equipment. In the course of this, a finely disperse, transparent microemulsion which can no longer be distinguished optically from a solution, is formed. <br><br>
The microemu Isions according to the invention can 10 be applied either in the form in which they have been prepared or after prior dilution. The quantity applied depends on the concentration of the active compounds in the microemulsion and on the particular indication. <br><br>
The use of the microemulsions according to the 15 invention is effected by the customary methods, that is to say, for example, by spraying, sprinkling or pouring. <br><br>
The preparation of the microemulsions according to the invention can be seen from the following examples. Preparation Examples 20 Example 1 <br><br>
8 g of an emulsifier mixture consisting of - 6 parts by weight of a nonylphenol polyglycol ether which has an average of 27 oxyethylene and 27 oxypropylene units per molecule, <br><br>
25 and <br><br>
4 parts by weight of calcium 4-(n-dodecyI)-pheny l-sulphonate (dissolved in n-butanol), <br><br>
is added, at temperatures between 20°C and 40°C and while stirring, to 70 g of the insecticidal active compound 30 0,0-dimethyl 0-(4-methyI mercapto-3-methyIphenyI) thionophosphate. The homogeneous solution thus formed is poured, in the course of 2 minutes and while stirring vigorously, <br><br>
into 22 g of deionised water. When the addition is complete, stirring is continued for a further 5 minutes. A 35 transparent microemulsion is formed, which exhibits no physical or chemical changes even after storage at elevated <br><br></p>
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