Compositions and method for improving the wetting of particulates

Abstract: New and improved compositions comprising particulates and an effective amount of one or more effective salt(s) to reduce significantly the wetting time and/or the dispersion time of said particulates relative to said time(s) in the absence of said salt(s) have been discovered. Methods for reducing the wetting time of particulates in liquid have also been discovered.

Description: Compositions containing particulates are often admixed with liquid compositions for application purposes. This broad operation includes mixing of powders in the household to making medical solutions to other applications such as on-site preparation of solutions in industrial or agricultural applications. Examples, without limitations, range from mixing flour with water in baking to making herbicidal or fungicidal agricultural compositions for field spraying or other distributing methods. One parameter of such operations is the time that it takes for the particulates to become wetted (i.e. "wetting time" or "wet-out time") to permit dispersion or dissolution of the particulates in a liquid application medium. "Wetting time" or "wet-out time" can be designated as the time for a known weight of solids poured on top of water in a container to submerge completely below the surface of the water. The wetting time can have a major impact on the time of operations, delays associated therewith, the degree of completeness of dissolution or dispersion and the effectiveness of the applied composition. There continues to be a need for new and/or improved methods to improve the wetting time of particulates. JP-A-56133202 discloses the addition of iron and/or copper salts as trace elements to manganese ethylene bisdithiocarbamate. However, since the trace elements added result in decrease in fungicidal activity and increase in phytotoxicity, a zinc or nickel compound is added as stabiliser to avoid such deleterious effects of the iron/copper salts. US-A-5,001,150 discloses the production of spray dried, non-dusty, dry-flowable granules of mancozeb which have aging stability, low ethylenethiourea content and improved dispersibility. The dry-flowable mancozeb granules are produced by initially preparing an aqueous slurry of maneb, zinc sulfate and various other components (including dispersant and surfactant) and then spray drying this slurry to produce the granules. The zinc sulfate is added for the purpose of reacting with the maneb to produce the mancozeb. We have surprisingly discovered that the addition to particulate compositions of certain salts increases the penetration rate of liquid into the particulates relative to the rate of penetration in the absence of said salt(s), and thereby can reduce the wetting time and/or the dispersion time of said particulates in liquids. According to the present invention there is provided the use, in a particulate composition, of one or more of ammonium, boron, zinc, manganese, copper, iron, cobalt, aluminum, magnesium, calcium, strontium, sodium, barium, gallium, tin, lead, silver, nickel or potassium salts to improve the penetration rate of a liquid into the particulates such that the wet-out time of said composition is at least 30% less than the wet-out time of a comparable composition comprising identical particulates and none of said salts. The incorporation of such salts into particulate compositions is shown to increase the penetration rate of liquid into the particulates relative to the rate of penetration in the absence of said salt(s), and consequently to reduce the wetting and/or dispersion time. For example, the wet-out time of the composition may be at least 50% less, preferably at least 75% less, than the wet-out time of a comparable composition comprising identical particulates and none of the salts. Mixing of the salts with the particulates may occur before, during or after addition of the particulates to the liquid. The methods can include simple admixing steps or milling of the solid particulates with the salt(s) so as to adfix or adhere the salt to the surface of the solid particulate. The particulates and liquid in the invention can be any suitable combination of particulates and liquid for an intended utility. For example, the particulates could be commercial foodstuff, e.g. powdered milk, flour etc., and the liquid can be water or water-containing solutions (e.g. milk). Other combinations include agricultural utilities, such as in-field formulations of agrochemicals, e.g. herbicides etc., and water. It is not intended that the present invention is limited to water as the liquid by these examples. The salts suitable for use in the present invention preferably comprise ammonium or boron, or one or more metals selected from zinc, manganese, copper, iron, cobalt, aluminum, magnesium, calcium, strontium, sodium, barium, tin, lead, silver, nickel, and potassium. Such ammonium, boron or metal moieties are alternatively referred to as the cation of the salt. The anionic portion of the salt is preferably a moiety such that the one or more salt(s) has an anion portion which is SO 4 -2 ,Cl -1 , Br -1 , I -1 , C 2 H 3 O 2 -1 , CO 3 -2 , NO 3 -1 , OH -1 , S -2 , PO 4 -3 , AlO 2 -1 , AsO 3 -3 , HAsO 3 -2 , H 2 AsO 3 -1 , AsO 4 -3 , HAsO 4 -2 , H 2 AsO 4 -1 , B 4 O 7 -2 , CN -1 , PO 3 -3 , HPO 3 -2 , H 2 PO 3 -1 , HPO 4 -2 , , H 2 PO 4 -1 , P 2 O 7 -4 , S 2 O 6 -2 , CHO 2 -1 , SO 3 -2 or a mixture thereof. In a preferred embodiment of the invention the salt comprises zinc chloride. The amount of salt used is that amount which is effective to increase the penetration rate of liquid into the particulate, preferably a significant amount of increase. For example, the increase in penetration rate is such that the wet-out time is about thirty percent less, more preferably about fifty percent less, even more preferably about seventy-five percent less, than that without the salts. The weight amount of the salt can range preferably from about 0.1 to about 50 weight percent, more preferably from about 0.1 to about 10 weight percent, even more preferably from about 0.1 to about 6 weight percent, of the total solid composition weight. In one preferred embodied composition the amount of effective salt in the composition is in a weight percent of from about 0.1 percent to about 6 percent and the wet-out time of the composition is less than about fifty percent of the wet-out time of a comparable composition having an absence of said salt. The particular form or nature of the salt can vary and still provide the benefits of the present invention. For instance, the one or more salt(s) can comprise a multiple salt complex, ie a complex of two or more different salts. For example, a multiple salt complex can be represented by the formula 2NaCl·CaCl 2 or K 2 CO 3 ·Na 2 CO 3 . Such multiple salt complexes can be hydrated, such as ZnCl 2 ·3ZnO·5H 2 O for example. Other salts may also be hydrated, such as for example CuSO 4 ·H 2 O. The ratio of salt molecules to water molecules need not be one to one. The salt need not consist of only one cation in the salt compound. Accordingly, embodied compositions can comprise a multiple cation salt. One example of a multiple salt is K 2 Zn(SO 4 ) 2 . Similarly, the anionic portion can have multiple anions. One embodiment of the present invention is wherein the one or more salt(s) comprise a melted salt. A mixture of salts can be melted together for the melted salt. Examples are 2NaCl·CaCl 2 , Na 2 SO 4 ·MgSO 4 , and 2NaCl·SrCl 2 . In a preferred embodiment of the present invention the one or more salts comprise a multiple salt complex or a hydrated salt or a multiple cation salt or a melted salt. Without limiting the scope of the present invention, the following salts are representative of those of the invention: Zn(C 2 H 3 O 2 ) 2 ·H 2 O Zn(C 2 H 3 O 2 ) 2 ·2H 2 O Zn(C 2 H 3 O) 2 CuCl 2 CuSO 4 Cu(NO 3 ) 2 MnCl 2 ·4H 2 O MnCl 2 MnCl 2 ·2H 2 O ZnSO 4 ZnSO 4 ·H 2 O MnSO 4 CuCl 2 ·2H 2 O CuSO 4 ·H 2 O ZnBr 2 ZnI 2 MnSO 4 ·H 2 O Mn(NO 3 ) 2 Mn(CHO 2 ) 2 FeCl 2 Mn(C 2 H 3 O 2 ) 2 FeCl 3 FeCl 2 ·2H 2 O FeCl 2 ·4H 2 O FeCl 3 ·2.5H 2 O FeCl 3 ·6H 2 O FeSO 4 FeSO 4 ·H 2 O FeSO 4 ·4H 2 O CoCl 2 CoBr 2 BBr 3 CoCl 2 ·2H 2 O AlCl 3 AlCl 3 ·6H 2 O AlBr 3 AlI 3 Al 2 S 3 AlCl 3 ·SO 2 AlCl 3 ·5SO 2 AlCl 3 ·5H 2 S Al 2 (SO 4 ) 3 ·6H 2 O Al 2 (SO 4 ) 3 ·18H 2 O AlCl 3 ·NH 3 AlCl 3 ·3NH 3 AlCl 3 ·NH 4 Cl AlCl 3 ·5NH 3 AlCl 3 ·6NH 3 AlCl 3 ·9NH 3 AlCl 3 ·3/4ZnCl 2 AlCl 3 ·AgCl MgCl 2 MgCl 2 ·2H 2 O MgCl 2 ·4H 2 O MgCl 2 ·6H 2 O MgBr 2 MgSO 4 MgSO 4 ·H 2 O MgSO 4 ·2H 2 O CaCl 2 CaCl 2 ·H 2 O CaCl 2 ·2H 2 O Ca(NO 3 ) 2 CaBr 2 Ca(C 2 H 3 O 2 ) 2 ·H 2 O CaI 2 CaSO 4 MgI 2 MgSO 4 ·4H 2 O SrO SrCl 2 SrBr 2 SrBr 2 ·H 2 O SrBr 2 ·2H 2 O Na 2 O NaOH NaOH·1/2H 2 O NaOH ·H 2 O Na 2 S NaHS 2 Na 2 Se NaPO 3 Na 2 P 2 Cl 7 Na 2 HPO 3 Na 2 HPO 4 Na 3 HP 2 O 7 Na 2 CO 3 NaCl·AlCl 3 3NaCl·2AlCl 3 KOH K 2 CO 3 ·Na 2 CO 3 ZnCl 2 K 2 CO 3 ·2NaCO 3 K 2 CO 3 ·3Na 2 CO 3 K 2 CO 3 ·4Na 2 CO 3 K 2 S 2K 2 CO 3 ·Na 2 CO 3 3K 2 CO 3 ·Na 2 CO 3 K 2 CO 3 ·1/2H 2 O KC 2 H 3 O 2 K 2 Zn(SO 4 ) 2 KCl·AlCl 3 2KCN·Zn(CN) 2 KCl·MgCl 2 K 2 SO 4 ·CuSO 4 3KCl·2AlCl 3 3KCl·AlCl 3 2KCl·MgCl 2 Mn(C 2 H 3 O 2 ) 2 ·4H 2 O 4KCl·MgCl 2 K 2 Mg(SO 4 ) 2 2KCl·CaCl 2 Melted salt mixtures: Na 2 SO 4 ·MgSO 4 2NaCl·CaCl 2 2NaCl·SrCl 2 Other embodiments include compositions wherein the solid particulates comprise propanil or one or more dithiocarbamate or bisdithiocarbamoyl disulfide compound(s). In one embodiment there is preferred one or more dithiocarbamate compound(s) which are selected from ethylenebisdithiocarbamate metal salts, dimethyldithiocarbamate metal salts, propylenebisdithiocarbamate metal salts, and/or metiram-complex. Metiram-complex can be named as tris [ammine-[ethylen bis (dithiocarbamato)] zinc (II)] [tetrahydro-1,2,4,7-dithiadiazocine-3,8-dithione] polymer. In another embodiment, thiram [e.g. bis (dimethylthio-carbamoyl) disulfide] can be used in place of the dithiocarbamate compound. A preferred ethylenebisdithiocarbamate metal salt comprises zinc chloride. Also preferred are compositions wherein the solid particulates comprise N-(3,4-dichlorophenyl)propionamide (propanil). Such compositions can have applications in agricultural operations. Embodied compositions can additionally comprise a surface active agent in an amount up to about 20 weight percent of the total composition weight, preferably from about 0.1 percent to about 15 percent, more preferably from about 1 percent to about 10 percent. Preferred surface active agents are, but are not limited to, a group consisting of Wafex™ dispersant, Igepal™ CA 720 surfactant, Igepal CO 630 surfactant, Igepal DM 970 surfactant, Borresperse™ NA ligosulfonate, Aerosol™ OT-70PG surfactant, and Surfynol™ 104 S surfactant. The following examples are intended to illustrate but not limit the scope of the embodied invention. EXPERIMENT 1 A comparison of wetting time was made between regular baking flour without zinc chloride and with zinc chloride. "Wetting time" or "wet-out time" is defined as the time for a known weight of solids poured on top of water in a container to submerge completely below the surface of the water. The samples of flour with zinc chloride were prepared by first admixing the flour and zinc chloride powder (98%, A.C.S. reagent, Aldrich Chemical Company, Inc.) before addition to 100 ml of tap water for timing to wet-out condition. No stirring was performed after the addition of sample to the water. The following results were obtained: Sample No. Flour Weight (grams) ZnCl 2 Weight (grams) Wet-Out Time (seconds) 1 5.00 0.30 302 2 5.00 0.30 269 3 5.00 0.00 815 4 5.00 0.00 790 EXPERIMENT 2 A mancozeb powder was produced by spray-drying a slurry comprised of the following components: Component Weight Percent Maneb Wet-cake 65.9 ZnSO 4 ·7H 2 O 3.8 Hexamethylenetetramine Stabilizer 1.1 Reax™ 100M Dispersant 3.3 Water 25.9 The spray-dried mancozeb powder was separated into two samples, one sample being dry mixed with zinc chloride in a weight ratio of zinc chloride:mancozeb = 2:100. Using procedures similar to Experiment 1, the following results were observed: Sample Wet-out time (Minutes) without ZnCl 2 12.0 with ZnCl 2 3.5 EXPERIMENT 3 Samples of mancozeb powders which were sprayed-dried to a moisture content of about 6 to about 9 percent water by weight were produced from slurries comprising admixed 65.9 weight percent maneb wet-cake and 1.1 weight percent hexamethylenetetramine stabilizer as well as the following components in the reported weight percentages. The respective reported wet-out times were observed. Suspensibility of each sample was determined using the modified WHO method of admixing 2 grams of sample in 250 grams of water in a 250 milliliter cylinder, inverting thirty times and, after thirty minutes, collecting the bottom ten percent, which is then dried and weighed relative to the original 2 grams. The suspensibility for the samples ranged from about 60 to about 80 percent. Sample No ZnSO 4 ·7H 2 O ZnCl 2 Surface Active Agent Water Wet-Out Time(secs) 1 3.8 0.0 3.3 27.85 779 2 3.8 0.0 2.0 26.2 280 3 3.8 0.0 2.0 26.7 80 0.5 4 3.8 0.0 2.0 26.7 73 0.5 5 3.8 0.0 2.0 26.7 51 0.5 6 1.9 0.9 2.0 28.2 60 7 0.0 1.8 3.3 27.85 55 8 0.0 1.8 2.9 26.62 28 0.63 9 0.0 1.8 2.9 27.3 26 1 10 0.0 1.8 2.0 29.2 16

Claims: The use, in a particulate composition, of one or more of ammonium, boron, zinc, manganese, copper, iron, cobalt, aluminum, magnesium, calcium, strontium, sodium, barium, gallium, tin, lead, silver, nickel or potassium salts to improve the penetration rate of a liquid into the particulates such that the wet-out time of said composition is at least 30% less than the wet-out time of a comparable composition comprising identical particulates and none of said salts. Use as claimed in claim 1, wherein said one or more salts are used in an amount of 0.1 to 50 weight percent. Use as claimed in claim 2, wherein said one or more salts are used in an amount of 0.1 to 10 weight percent. Use as claimed in claim 3, wherein said one or more salts are used in an amount of 0.1 to 6 weight percent. Use as claimed in any preceding claim, wherein said one or more salts has an anion portion which is SO 4 -2 , Cl -1 , Br -1 , I -1 , C 2 H 3 O 2 -1 , CO 3 -2 , NO 3 -1 , OH -1 , S -2 , PO 4 -3 , AlO 2 -2 , AsO 3 -3 , HAsO 3 -2 , H 2 AsO 3 -1 , AsO 4 -3 , HAsO 4 -2 , H 2 AsO 4 -1 , B 4 O 7 -2 , CN -1 , PO 3 -3 , HPO 3 -2 , H 2 PO 3 -1 , HPO 4 -2 , H 2 PO 4 -1 , P 2 O 7 -4 , S 2 O 6 -2 , CHO 2 -1 , SO 3 -2 or a mixture thereof. Use as claimed in any preceding claim, wherein said salt comprises zinc chloride. Use as claimed in any of claims 1 to 5, wherein said one or more salts comprises a multiple salt complex or a hydrated salt or a multiple cation salt or a melted salt. Use as claimed in claim 7, wherein:- (a). said multiple complex salt is 2NaCl·CaCl 2 or K 2 CO 3 ·Na 2 CO 3 ; and/or (b). said hydrated salt is CuSO 4 ·H 2 O; and/or (c). said multiple cation salt is K 2 Zn(SO 4 ) 2 ; and/or (d). said melted salt is 2NaCl·CaCl 2 . Use as claimed in any preceding claim, wherein said particulates comprise propanil or one or more dithiocarbamate or bisdithiocarbamoyl disulfide compound(s). Use as claimed in claim 9, wherein said one or more dithiocarbamate compounds are selected from ethylenebisdithiocarbamate metal salts, dimethyldithiocarbamate metal salts, propylenebisdithiocarbamate metal salts and metiram-complexes. Use as claimed in claim 10, wherein said ethylenebisdithiocarbamate metal salt comprises zinc chloride. Use as claimed in claim 10 or claim 11, wherein said composition further comprises a surface active agent in an amount up to 20 weight percent of the total composition weight. Use as claimed in claim 12, wherein said surface active agent is present in an amount of 0.1 to 15 weight percent of the total composition weight. Use as claimed in claim 13, wherein said surfcae active agent is present in an amount of 1 to 10 weight percent of the total composition weight. Use as claimed in any preceding claim, wherein the wet-out time of said composition is at least 50% less than the wet-out time of a comparable composition comprising identical particulates and none of said salts. Use as claimed in claim 15, wherein the wet-out time of said composition is at least 75% less than the wet-out time of a comparable composition comprising identical particulates and none of said salts.

Inventors: GUO YILI, GUO, YILI
Applicants: ROHM & HAAS, ROHM AND HAAS COMPANY
Application year: 1993
Main classification: B01F17
IPC codes: C01G9, A23C9, B01F17, B01J20, C11D7, A01N25