Formulations comprising phosphite

Abstract

The invention relates to an aqueous suspension comprising a solubilized salt and insolubilized ingredients such as lignosulfonate and a dodecyl sulfate salt. The invention further relates to methods of producing said aqueous suspension, and to methods to employ said suspension for fertilizing agricultural plants and for protecting a plant or plant part against a pathogen. The invention additionally relates to methods of preventing, reducing and/or eliminating the presence of a pathogen on a plant or plant part, and to methods for treatment of a soil, comprising providing a suspension according to the invention.

Claims

1. A stable aqueous suspension of phosphite comprising a solubilized phosphite salt at 20-50% (w/w), insolubilized lignosulfonate at 2-30% (w/w), a dodecyl sulfate salt as an insolubilized anionic surfactant at 0.5-10% (w/w), and an ethylene oxide/propylene oxide block copolymer at 0.2-3% (w/w).

2. The suspension according to claim 1, wherein the solubilized phosphite salt is disodium hydrogen phosphite.

3. The suspension according to claim 1, wherein the anionic surfactant is sodium dodecyl sulfate.

4. The suspension according to claim 1, wherein the ethylene oxide/propylene oxide block copolymer is polyoxypropylene that is flanked by two chains of polyoxyethylene.

5. The suspension according to claim 4, wherein the block polymer has a molecular mass of about 2000 g/mol and a 10% polyoxyethylene content by weight.

6. The suspension according to claim 1, wherein the average particle size is between 0.2 and 5 micrometers.

7. A method of fertilizing an agricultural plant, comprising applying to said agricultural plant the suspension according to claim 1.

8. A method of protecting an agricultural plant or plant part against a pathogen, comprising applying to said agricultural plant or to said plant part the suspension according to claim 1.

9. A method of preventing, reducing and/or eliminating the presence of a pathogen on a plant or on one or more plant parts, comprising applying to said plant or plant part the suspension according to claim 1.

10. The method of claim 8, wherein the plant part comprises seed, leaf or fruit.

11. A method for treatment of a soil, comprising a) providing the suspension according to claim 1; and b) adding the suspension to the soil.

12. The method according to claim 8, wherein the suspension is diluted with an aqueous liquid and mixed with a fungicide prior to application to said plant or plant part.

13. The method according to claim 10, wherein the plant part is a post-harvest fruit.

14. The method according to claim 9, wherein the plant part comprises seed, leaf or fruit.

15. The method according to claim 14, wherein the plant part is a post-harvest fruit.

16. The method according to claim 11, wherein the soil is a growth substrate for mushrooms.

17. The method according to claim 12, wherein the fungicide is a metal-containing fungicide.

18. The method according to claim 11, wherein the suspension is diluted with an aqueous liquid and mixed with a fungicide prior to application to said soil.

19. A method of producing a stable aqueous suspension of phosphite, said method comprising providing a 10-50% (w/w) aqueous solution of a solubilized phosphite salt, adding 2-20% (w/w) of powderous lignosulfonate to said solution, adding 0.5-10% (w/w) of powderous dodecyl sulfate salt, and adding 0.2-2% (w/w) of an ethylene oxide/propylene oxide block copolymer.

20. The method of producing an aqueous suspension according to claim 19, further comprising crushing the resulting suspension to an average particle size of between 0.2 and 5 micrometers.

21. The method according to claim 20, whereby the suspension is crushed by milling.

Description

EXAMPLES

Example 1

(1) Experiments were performed to search for an optimal surfactant combination which provides a stable, highly concentrated suspension of phosphite that is compatible to mixing with other agricultural active ingredients. All experiments were performed with 500 g/L Na2HPO3 and undissolved calcium lignosulfonate in the presence of a polyalkylene-oxyde block copolymer (Synperonic PE/L61 (Croda); 0.9% (w/w)). A summary of the experiments is provided in Table 1.

(2) CIPAC MT 46.3 (Accelerated storage procedures), by storing the formulations at 54 C. over a period of 2 weeks was applied to check whether a formulation is stable or not is.

(3) From all tested combinations, a stable suspension was only obtained when using HELIWET NLS 90 (Mosselman s.a., B-7011 Ghlin, Belgium), in combination with Synperonic PE/L61.

(4) The stabilizing effects of HELIWET NLS 90, in combination with Synperonic PE/L61, were found in the range of 0.5-5% (w/w) for HELIWET NLS 90, and 0.5-1.5% (w/w) for Synperonic PE/L61.

(5) TABLE-US-00001 TABLE 1 Surfactant combination used Anion surfactant Non-ionic surfactant Comment Sodium di-octylsuccinate Phase separation Emulsogen SF8 Liquid within 24 hours (Clariant) Dosage: 2.5-5% Fatty alkoholethoxylate (30) Highly insoluble and Genapol EP 2584 (Clariant) flocculation Dosage: 2-4% Dodecylbenzenesulphonate Phase separation Heloxyl AL 80 (Chempri) within 7 days Dosage: 2.5-5% Polyoxyethylene C12-C15 Phase separation alcohol (20) within one hour Synperonic A20 (Croda) Dosage: 2.5-5% Acrylic copolymer solution Flocculation formed Atlox 4913 (Croda) immediately Dosage: 3.5% Polyarylphenol-ethoxylate Insoluble (direct phase phosphate separation) Amm.salt Soprophor FL (Azelis) Dosage: 2-3% Sulfonated Aromatic Increase in viscosity at Polymer temperature >30 C. Morwet D425 (Akzo) Dosage: 2.5-5% Polyoxyethylene-20 Sorbitan Flocculation formed mono-laurate Tween 20 immediately (Croda) Dosage: 3% Amine Increased viscosity at alkylbenzenesulfonate temperature >30 C. Zephrym 3300B (Croda) Dosage: 2-3% Sodium-N-Methyl Oleyl Phase separation, Taurate increase viscosity. Adinol OT-72 (Croda) Dosage: 2-4% Sodium dodecyl sulfate Stable product HELIWET NLS 90 (Mosselman s.a., B-7011 Ghlin, Belgium). Dosage: 1-5%

Example 2

(6) In this experiment, anionic surfactants were tested that have physical/chemical properties close to those of anionic surfactant Heliwet NLS 90.

(7) These surfactants are: 1. Atlox 2575 (alkyl polysaccharide with CAS number 68515-73-1). Croda Crop Care, Snaith Goole, UK). 2. Metasperse 550S-PW-(WD) (styrene (meth)acrylic copolymer, Atlox Metasperse 550S (Croda Crop Care, Snaith Goole, UK). 3. Sodiumlaurylethersulfate (C12-C14 ethoxlylated (2.5 e.o) sulfated sodiumsalt CAS:68891-38-3). 4. Sodiumlaurylsulphate Mackol CAS 100N (C12-C18 Sulfated sodiumsalt CAS:68955-19-1; Rhodia, France).

(8) Testing of the different surfactants was performed in a phosphite-calcium lignosulfonate product. A stock solution (amounts of the compounds used: see Table 2 below) containing all ingredients except the anionic surfactant was prepared by subsequently: Dissolving H3PO3 in water Adding NaOH to a pH of 8.15 Adding calcium lignosulfonate Adding Silcolapse 416 en Synperonic PE/L61 Mixing for at least 30 minutes Addition of the anionic surfactant Mixing for another 20 minutes

(9) TABLE-US-00002 TABLE 2 Composition of the product in which the different anionic surfactants were tested. Compound Amount (g/l) H3PO3 (99% pure) 325.4 NaOH (99% pure) 317.4 H2O 586.3 Calciumlignosulfonate 125.0 Anionic surfactant* 20.9 Synperonic PE/L61 12.5 Silcolapse 416 2.5

(10) After mixing of the anionic surfactant in the product, the resulting mixture was milled on a bead mill apparatus for 25 minutes.

(11) Test results: After milling the products with the different anionic surfactants were stored at 4 and 40 C.

(12) Results of the CIPAC tests MT46.1 (accelerated storage at high temp) and MT 39.1 (low temperature storage stability) are shown in Table 3.

(13) TABLE-US-00003 TABLE 3 Anionic surfactants used Anionic surfactant used Observation during Observation during Product in the product storage at 4 C. storage at 40 C. stability Atlox 2575 At 4 C., the product Solution contained Not stable became very viscous large lumps within 1 (almost solid) within 1 week week Metasperse 550S At 4 C. the product Phase separation in Not stable became very viscous three layers within 1 (almost solid) within 1 week week Sodiumlaurylethersulfate At 4 C. the product Phase separation: Not stable became very viscous large top layer with (almost solid) within 1 very high viscosity week (almost solid) and bottom layer low viscosity, within 1 week Sodiumlaurylsulphate Good viscosity no Increase in viscosity, Not stable Mackol CAS 100N phase separation no phase separation within 2 weeks within 2 weeks Heliwet NLS 90 Good viscosity no Good viscosity no Stable (sodiumlaurylsulphate phase separation phase separation product type) within 2 weeks within 2 weeks

(14) The results show that the formulation containing Heliwet NLS 90 was stable after 14 days of storage at 4 and 40 C. The product with sodiumlaurylsulphate Mackol CAS 100N remained stable at 4 C. but the viscosity of the product increased at 40 C. making the product not stable according to Cipac standards. These surfactants are very similar: both are non-ethoxylated sulfated sodium salts. The only difference is that Heliwet NLS 90 has a molecular chain length of C12-C14 and sodiumlaurylsulphate Mackol CAS 100N has a chain length of C12-C18. The other surfactants that are physical/chemical related to Heliwet NLS90 resulted to in clearly unstable products.