Aqueous agrochemical suspension composition and method for spraying same

Abstract

An object of the present invention is to provide: an aqueous suspension agrochemical composition having a good storage stability, with which an increase in the viscosity of a formulation can be inhibited even when the composition contains a high concentration of pyroxasulfone; and a process of spraying the same. The present invention provides: an aqueous suspension agrochemical composition containing: pyroxasulfone; an acrylic graft copolymer; an alcohol alkoxylate; and a lignin sulfonate, in which composition the alcohol alkoxylate contains a polyoxyethylene alkyl ether; and a process of spraying an aqueous suspension agrochemical composition, the process including spraying the above-described aqueous suspension agrochemical composition to a field where agricultural/horticultural plants grow.

Claims

1. An aqueous suspension agrochemical composition comprising: pyroxasulfone; an acrylic graft copolymer of an acrylic polymer and a polyethylene glycol; an alcohol alkoxylate; and a lignin sulfonate, wherein the alcohol alkoxylate comprises a polyoxyethylene alkyl ether, and wherein the content ratio of pyroxasulfone is 50% or higher in terms of mass with respect to a total amount.

2. The aqueous suspension agrochemical composition according to claim 1, wherein the polyoxyethylene alkyl ether is an ethoxylation product of an aliphatic alcohol, and wherein the aliphatic alcohol has 12 to 15 carbon atoms and an average number of moles of added ethylene oxide of 5 to 9.

3. The aqueous suspension agrochemical composition according to claim 1, wherein the alcohol alkoxylate further comprises an alkoxyalkyl ether of a polyoxyethylene-polyoxypropylene block copolymer.

4. The aqueous suspension agrochemical composition according to claim 1, wherein the lignin sulfonate is a sodium salt, a potassium salt, a calcium salt, a magnesium salt, an ammonium salt, or a primary to quaternary substituted ammonium salt.

5. The aqueous suspension agrochemical composition according to claim 1, wherein the content ratio of pyroxasulfone is 55% or higher in terms of mass with respect to a total amount.

6. The aqueous suspension agrochemical composition according to claim 1, wherein the content ratio of pyroxasulfone is 60% or higher in terms of mass with respect to a total amount.

7. The aqueous suspension agrochemical composition according to claim 1, wherein the viscosity at 20° C., which is measured using a B-type viscometer at a rotation speed of 30 rpm after the aqueous suspension agrochemical composition is left to stand at 54° C. for 2 weeks, is 100 to 1,000 mPa.Math.s.

8. A process of spraying an aqueous suspension agrochemical composition, the process comprising spraying the aqueous suspension agrochemical composition according to claim 1 to a field where agricultural/horticultural plants grow.

Description

EXAMPLES

(1) The present invention will now be described in detail by way of Examples thereof; however, the present invention is not restricted thereto by any means. It is noted here that, in the below-described Examples, “part(s)” and “%” mean “part(s) by mass” and “% by mass”, respectively. The particle size is the average particle size (volume median diameter) measured using a laser diffraction-scattering particle size distribution analyzer (trade name “LASER MICRON SIZER LMS-2000e”, manufactured by Seishin Enterprise Co., Ltd.). The viscosity is a value measured for each sample at 20° C. and 30 rpm using a B-type viscometer (trade name “TVB-10-M”, manufactured by Toki Sangyo Co., Ltd.).

Examples 1 to 18 and Comparative Examples 1 to 5

(2) The materials shown in Tables 1 to 5 were mixed at the respective ratios (parts by mass) shown in Tables 1 to 5, and the resulting mixtures were each subsequently wet-ground to obtain pyroxasulfone-containing aqueous suspension agrochemical compositions. For the thus obtained aqueous suspension agrochemical compositions, the particle size, the viscosity and the suspensibility were measured, and the separation rate, the caking and the redispersibility were evaluated. In addition, for the aqueous suspension agrochemical compositions that were left to stand at 54° C. for 2 weeks, the particle size, the viscosity and the suspensibility were measured. The results thereof are shown in Tables below. It is noted here that pyroxasulfone used in Examples had a purity of 99.2%.

(3) (Suspensibility)

(4) For 1,400 mg of each of the thus obtained aqueous suspension agrochemical compositions, the suspensibility was measured in accordance with CIPAC MT184. In addition, the suspensibility was also measured in the same manner after a lapse of 2 weeks at 54° C.

(5) (Separation Rate)

(6) The thus obtained aqueous suspension agrochemical compositions were each placed in a cylindrical container and statically stored, after which the amount of the resulting supernatant and that of the whole liquid were measured in terms of height using a ruler, and the ratio of the height of the supernatant with respect to the height of the whole liquid was determined as the separation rate.

(7) (Caking)

(8) For each of the thus obtained aqueous suspension agrochemical compositions, the degree of caking on the bottom of a sample container was examined using a spatula. The evaluations of caking that are shown in Tables 1 to 5 were made based on the following criteria.

(9) −: No viscous matter was observed on the bottom of the container.

(10) ±: A small amount of viscous matter was observed on the bottom of the container.

(11) +: A viscous matter was observed on the bottom of the container.

(12) ++: An aggregate of viscous matter was observed on the bottom of the container.

(13) (Redispersibility)

(14) The thus obtained aqueous suspension agrochemical compositions were each shaken to examine the degree of separation and the degree of dispersion of caking.

(15) ∘: The aqueous suspension agrochemical composition was readily dispersed by shaking.

(16) x: A sample remained on the bottom even with vigorous shaking.

(17) TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 Com- Pyroxasulfone 60.48 60.48 60.48 60.48 60.48 position Acrylic graft 0.50 1.00 1.50 2.00 2.50 copolymer*.sup.1 Alcohol alkoxylate 1*.sup.2 1.00 1.00 1.00 1.00 1.00 Lignin sulfonate*.sup.3 3.00 3.00 3.00 3.00 3.00 Antifreezing agent*.sup.4 5.00 5.00 5.00 5.00 5.00 Thickening agent*.sup.5 0.20 0.20 0.20 0.20 0.20 Antifoaming agent*.sup.6 0.20 0.20 0.20 0.20 0.20 Preservative*.sup.7 0.03 0.03 0.03 0.03 0.03 Water remainder remainder remainder remainder remainder Total 100.00 100.00 100.00 100.00 100.00 Physical Particle Initial 2.5 2.5 2.6 2.5 2.6 prop- size (μm) 54° C. × 2.7 2.6 2.6 2.6 2.6 erties 2 weeks Viscosity Initial 1,375 1,244 1,231 798 1,136 (mPa .Math. s) 54° C. × 323 337 303 265 331 2 weeks Suspen- Initial 63.5 69.4 80.4 84.3 93.4 sibility 54° C. × 62.2 74.7 83.4 91.7 89.1 (%) 2 weeks Separation rate (%) 0 6 4 4 6 Caking — — — — — Redispersibility ∘ ∘ ∘ ∘ ∘ *.sup.1polyethylene glycol-polymethyl methacrylate graft copolymer (trade name: “ATLOX ™ 4913-LQ-(MV)”, manufactured by Croda International Plc) *.sup.2mixture of polyoxyethylene (n = 5 to 9) C.sub.12 to C.sub.15 alkyl ether and polyoxyethylene/polyoxypropylene-4-butoxybutyl ether (trade name “ATLOX ™ 4894-LQ-(MV)”, manufactured by Croda International Plc) *.sup.3sodium lignin sulfonate (trade name “PEARLLEX NP”, manufactured by Nippon Paper Industries Co., Ltd.) *.sup.4propylene glycol *.sup.5bentonite (trade name “KUNIPIA F”, manufactured by Kunimine Industries, Co., Ltd.) *.sup.6silicone-based antifoaming agent (trade name “ASAHI SILICONE AF-128”, manufactured by Asahi Chemical Co., Ltd.) *.sup.75-chloro-2-methyl-4-isothiazolin-3-one (trade name “BIOHOPE L”, manufactured by K.Math.I Chemical Industry Co., Ltd.)

(18) TABLE-US-00002 TABLE 2 Example 6 7 8 9 Com- Pyroxasulfone 60.48 60.48 60.48 60.48 position Acrylic graft copolymer*.sup.1 3.00 4.00 5.00 10.00 Alcohol alkoxylate 1*.sup.2 1.00 1.00 1.00 1.00 Lignin sulfonate*.sup.3 3.00 3.00 3.00 3.00 Antifreezing agent*.sup.4 5.00 5.00 5.00 5.00 Thickening agent*.sup.5 0.20 0.20 0.20 0.20 Antifoaming agent*.sup.6 0.20 0.20 0.20 0.20 Preservative*.sup.7 0.03 0.03 0.03 0.03 Water remainder remainder remainder remainder Total 100.00 100.00 100.00 100.00 Physical Particle Initial 2.5 2.4 2.4 1.9 properties size (μm) 54° C. × 2.6 2.6 2.6 2.1 2 weeks Viscosity Initial 1,013 820 734 1,504 (mPa .Math. s) 54° C. × 326 321 348 664 2 weeks Suspen- Initial 91.0 94.2 93.9 98.8 sibility 54° C. × 90.5 94.2 95.4 98.0 (%) 2 weeks Separation rate (%) 6 7 7 4 Caking — — — — Redispersibility ∘ ∘ ∘ ∘

(19) TABLE-US-00003 TABLE 3 Example 10 11 12 13 14 Com- Pyroxasulfone 60.48 60.48 60.48 60.48 60.48 position Acrylic graft 2.00 2.00 2.00 2.00 2.00 copolymer*.sup.1 Alcohol alkoxylate 1*.sup.2 1.00 1.50 2.00 5.00 8.00 Lignin sulfonate*.sup.3 3.00 3.00 3.00 3.00 3.00 Antifreezing agent*.sup.4 5.00 5.00 5.00 5.00 5.00 Thickening agent*.sup.5 0.20 0.20 0.20 0.20 0.20 Antifoaming agent*.sup.6 0.20 0.20 0.20 0.20 0.20 Preservative*.sup.7 0.03 0.03 0.03 0.03 0.03 Water remainder remainder remainder remainder remainder Total 100.00 100.00 100.00 100.00 100.00 Physical Particle Initial 2.5 2.0 2.0 2.5 2.3 prop- size (μm) 54° C. × 2.6 2.0 2.1 2.7 2.6 erties 2 weeks Viscosity Initial 798 1,713 1,296 1,164 2,669 (mPa .Math. s) 54° C. × 265 512 509 832 <1,000 2 weeks Suspen- Initial 84.3 95.4 95.6 86.8 97.2 sibility 54° C. × 91.7 92.3 95.4 94.9 96.2 (%) 2 weeks Separation rate (%) 4 0 4 4 4 Caking — — — — — Redispersibility ∘ ∘ ∘ ∘ ∘

(20) TABLE-US-00004 TABLE 4 Example 15 16 17 18 Com- Pyroxasulfone 60.48 60.48 60.48 60.48 position Acrylic graft copolymer*.sup.1 2.00 2.00 2.00 2.00 Alcohol alkoxylate 1*.sup.2 0 1.00 1.00 1.00 Alcohol alkoxylate 2*.sup.8 1.00 0 0 0 Lignin sulfonate*.sup.3 3.00 3.00 4.00 5.00 Antifreezing agent*.sup.4 5.00 5.00 5.00 5.00 Thickening agent*.sup.5 0.20 0.20 0.20 0.20 Antifoaming agent*.sup.6 0.20 0.20 0.20 0.20 Preseryative*.sup.7 0.03 0.03 0.03 0.03 Water remainder remainder remainder remainder Total 100.00 100.00 100.00 100.00 Physical Particle Initial 1.8 2.5 2.5 2.4 properties size (μm) 54° C. × 2.0 2.6 2.6 2.6 2 weeks Viscosity Initial 856 798 3,136 2,811 (mPa .Math. s) 54° C. × 687 265 514 504 2 weeks Suspen- Initial 98.3 84.3 96.5 97.3 sibility 54° C. × 97.4 91.7 95.3 96.1 (%) 2 weeks Separation rate (%) 0 4 0 0 Caking ± — — — Redispersibility Particle Initial Particle Initial *.sup.8polyoxyethylene (n = 5 to 9) C.sub.12 to C.sub.15 alkyl ether (trade name “SYNPERONIC ® A7”, manufactured by Croda International Plc)

(21) TABLE-US-00005 TABLE 5 Comparative Example 1 2 3 4 5 Com- Pyroxasulfone 60.48 60.48 60.48 60.48 0 position Diuron 0 0 0 0 60.48 Acrylic graft 0 2.00 2.00 2.00 2.00 copolymer*.sup.1 Alcohol alkoxylate 1*.sup.2 1.00 0 1.00 0 1.00 Polyoxyethylene/ 0 0 0 1.00 0 polyoxypropylene alkyl ether*.sup.9 Lignin sulfonate*.sup.3 3.00 3.00 0 3.00 3.00 Antifreezing agent*.sup.4 5.00 5.00 5.00 5.00 5.00 Thickening agent*.sup.5 0.20 0.20 0.20 0.20 0.20 Antifoaming agent*.sup.6 0.20 0.20 0.20 0.20 0.20 Preservative*.sup.7 0.03 0.03 0.03 0.03 0.03 Water remainder remainder remainder remainder remainder Total 100.00 100.00 100.00 100.00 100.00 Physical Particle Initial 2.6 2.6 2.3 1.9 2.8 prop- size (μm) 54° C. × 2.7 3.3 2.5 2.1 3.2 erties 2 weeks Viscosity Initial 1,471 1,342 439 1,118 431 (mPa .Math. s) 54° C. × 286 1,603 253 1,522 222 2 weeks Suspen- Initial 52.8 98.0 19.1 98.2 not sibility measured (%) 54° C. × 46.7 93.0 16.5 95.6 not 2 weeks measured Separation rate (%) 0 0 10 8 18 Caking — ++ — + ++ Redispersibility ∘ × ∘ × × *.sup.9trade name “PEPOL B-184” (manufactured by TOHO Chemical Industry Co., Ltd.)