FR2698242A1 - Compsns. contg. water-soluble herbicide or plant hormone - dispersed in mixt. of powdered mineral and oil or grease. - Google Patents

Abstract

Compsns. comprise a water-soluble herbicide or plant hormone dispersed in a carrier comprising: (a) up to 3.3 wt. % of a powdered absorbent mineral component with a water uptake above 15 wt. % where 90% of the particles are smaller than 40 microns; and (b) up to 66 wt. % of a hydrophobic component selected from animal, vegetable or mineral oils and greases. The compsns. pref. comprise 2-30 (esp. 5-20) wt. % ethephon, 0.4-2.5 (esp. 4-15) wt. % finely divided silica and/or clay, 7-60 (esp. 35-45) wt. % paraffinic mineral oil, 7-60 (esp. 40-60) wt. % petroleum, and less than 1 wt. % of a thickener, esp. a 'Rehodopol' (RTM) biopolymer. USE/ADVANTAGE - Compsns. contg. 2-chloroethylphosphonic acid (ethephon) are useful for stimulating latex secretion by Hevea trees. The compsn. are easy to apply, have a controlled-release effect and resist washing off by water (esp. rain).

Description

PHYTOSANITARY COMPOSITION
The subject of the invention is a plant protection composition of the kind comprising a water-soluble active ingredient chosen from the group comprising herbicidal substances and plant hormones.

 It relates more particularly to the phytosanitary compositions of the kind in question in which the active material is constituted by 2-chloroethylphosphonic acid normally designated by the term ethephon.

 One of the known applications of ethephon lies in its implementation for the stimulation of the secretion of rubber latex.

 This application is carried out by setting up the ethephon by means of a composition containing it on a part of the rubber tree, the bark of which has previously been removed to the vicinity of the laticiferous vessels.

It is found that the compositions of the kind in question which are already known have many disadvantages among which include:
- that of not having a delay effect,
- that of presenting insufficient resistance to
water runoff, particularly water from
rain.

The object of the invention is, above all, to overcome the disadvantages of the prior art and to provide a composition of the kind in question - which has an adjustable delay effect, possibly
combined with an immediate effect or "shock effect", which effectively resists water runoff, particularly
rainwater and - which is easy to apply and maintain on the
implementation site.

 And it is to the merit of the Applicant Company to have found that this goal was achieved when the active ingredient in the constitution of phytosanitary compositions of the genus in question was dispersed in a carrier consisting essentially of a mineral constituent, pulverulent and absorbent and a hydrophobic product of mineral, vegetable or animal origin.

It follows that the phytosanitary composition according to the invention is characterized in that it comprises a water-soluble active ingredient chosen from the group comprising herbicidal substances and plant hormones, dispersed in a support consisting of for not more than about 33% by weight of a constituent
mineral, powdery and absorbent
more than 15% by weight and 90% of which
constitutive particles have a particle size less than
than approximately 4ohm, - for not more than approximately 66% by weight of a hydro product
selected from the group consisting of oils and
fats of mineral, vegetable or animal origin.

According to an advantageous embodiment, the phytosanitary composition according to the invention is characterized in that it comprises: as active ingredient, from 2 to 30% by weight, of
preferably from 5 to 20% by weight, based on the mass
total composition, eventually etherphon
partially neutralized, - as a mineral constituent, powdered and absorbed
bant, from 0.4 to 25%, preferably from 4 to 15% by weight
relative to the total mass of the composition,
silica and / or clay powder with 90% of the particles
constituents have a particle size less than about 40%, as a hydrophobic product, from 7 to 60%, preferably
35 to 45% of a mineral oil with
pre-dominant paraffinic and 7 to 60%, preferably
from 40 to 60% by weight relative to the total mass of the
composition, a fat or vaseline firm type
petrolatum and - optionally less than 1% by weight per
relative to the total mass of the composition, an agent
rheological.

 The above composition may comprise from 2 to 12%, preferably from 3 to 6% of water.

 According to another advantageous embodiment, the phytosanitary composition according to the invention is characterized in that the ethephon is used in the form of an aqueous solution containing in particular 400 to 1000 g / l of active ingredient consisting of technical ethephon which is a waxy white solid melting at about 74-750C.

According to another advantageous embodiment, the phytosanitary composition according to the invention is characterized by the fact that
the silica powder is chosen from micronised, precipitated, pyrogenic, surface-treated silicas of natural or synthetic origin, this silica powder being able to be that marketed by the
DEGUSSA company under the brand AEROSIL 2009 and
that the clay powder consists essentially of metal aluminosilicates (for example of the Fe-Mg type) obtained from sedimentary rocks consisting essentially of phyllitous or fibrous minerals.

According to another advantageous embodiment, the phytosanitary composition according to the invention is characterized by the fact that
that the predominant paraffinic mineral oil is that marketed by FINA under the brand name Oil F 9805 and
- that fat or vaseline ferme is that marketed by SHELL under the name
Petrolatum S3285.

 According to another advantageous embodiment, the phytosanitary composition in accordance with the invention is characterized in that the rheological agent is constituted by a thickening agent of the carboxymethylcellulose type or by one or more of the biopolymers that can be obtained by fermentation in fermentation. presence of microorganisms of the Xanthomonas campestris type and marketed by RHÔNE-POULENC under the trademark RH0D0P0L.

The phytosanitary composition according to the invention may comprise: a protic solvent such as a C1 to Q short alcohol
and / or a glycol of the ethylene glycol or propylene type
glycol, - one or more surfactants, one or more
wetting agents, one or more dispersing agents,
optionally a dye and / or agents
preservatives and / or antioxidants and / or fragrances
or pheromones.

 The invention can be better understood by means of the additional description which follows and which essentially comprises examples of formulation of the phytosanitary compositions according to the invention as well as comparative examples showing the advantages of the phytosanitary compositions according to the invention. invention compared to the prior art.

 The composition according to the invention is in the form of a creamy paste that can be spread with a brush.

 Three compositions according to the invention, designated respectively by A, B and C, have been prepared.

The constituents selected for this preparation were:
- as regards ethephon: a 72% aqueous solution with a density of 1.389 and marketed by the
Applicant company under the brand BASE A250X,
- with regard to the mineral component: silica marketed under the trademark AEROSIL 200X,
- as regards the oil: that marketed under the trademark Oil F 9805X,
- As regards the fat, that marketed under the brand Petrolatum S3285.

 In Table I which follows, the proportions of the various constituents used for the preparation of compositions A, B and C were indicated.

TABLE I

<tb><SEP> Nature <SEP> of <SEP> Quantity <SEP> of <SEP> components <SEP> (in <SEP> g)
<tb><SEP> Constituents <SEP> Composition <SEP> A <SEP> Composition <SEP> B <SEP> Composition <SEP> C
<tb> Etephon <SEP> to <SEP> 72% <SEP> 6.95 <SEP> 6.95 <SEP> 6.95
<tb> Constituent <SEP> mineral <SEP> 4.93 <SEP> 5.07 <SEP> 5.20
<tb> Oil <SEP> 30.22 <SEP> 34.58 <SEP> 38.85
<tb> Fat <SEP> 57.90 <SEP> 53.40 <SEP> 49.00
<tb><SEP> 100.00 <SEP> 100.00 <SEP> 100.00
<Tb>
The compositions A, B and C are in the form of a creamy brown paste with 5% ethephon; this paste is spreadable with a brush.

 In some cases it is preferred to use partially neutralized thesphon.

 To prepare this partially neutralized ethephon, it is possible to use ethephon in the form of the aqueous solution described above.

 The neutralizing agent is generally selected from the group consisting of hydroxides, oxides, carbonates, alkali metal or alkaline earth metal bicarbonates, alkanolamines, optionally oxyalkylenated fatty amines and basic amides.

 In the case of neutralization with monoethanolamine, this is added slowly with stirring and under cooling with the etherphon solution.

 Since the neutralization reaction is highly exothermic, it is important to control the addition rate of monoethanolamine so that any significant heating and reaction is avoided.

 Three samples of partially neutralized ethephon were prepared in this way.

 These three samples, respectively called M, N and P have ethephon contents which are respectively 55, 58.4 and 62.3% by weight.

They are obtained by mixing:
76.75 g of the above solution of ethephon and
23.25 g of monoethanolamine with regard to
the sample M,
- 81.50 g of the above solution of ethephon and
18.50 g of monoethanolamine with regard to
sample N,
86.84 g of the above solution of ethephon and
13.16 g of monoethanolamine with regard to
the sample P.

 The molar ratio monoethanolamine / ethephon is 1 in the case of the sample M, 0.75 in the case of the sample N and 0.5 in the case of the sample P.

 The 200C appearance and pH of the M, N and P samples are shown in Table II.

TABLE II

<tb><SEP> Sample <SEP> M <SEP> Sample <SEP> N <SEP> Sample <SEP> P
<tb> Appearance <SEP> at <SEP> 20 C <SEP> Paste, <SEP> white <SEP> half liquid <SEP> liquid <SEP> syrupy
<tb><SEP> crystallized <SEP> half-pasty
<tb> pH <SEP> of <SEP> product <SEP> 3.25 <SEP> 2.7 <SEP> 1.9
<Tb>
Three partially neutralized ethephon-based compositions according to the invention have been prepared designated Composition D, Composition E and Composition F.

 The nature of the constituents is the same as in Table I.

 The constitution of compositions D, E and F results from Table III.

TABLE III

<tb><SEP> Nature <SEP> of <SEP> Quantity <SEP> of <SEP> components <SEP> (in <SEP> g)
<tb> constituents <SEP> Composition <SEP> D <SEP> | <SEP> Composition <SEP> E <SEP> | <SEP> Composition <SEP> F
<tb><SEP> Sample <SEP> M <SEP> 9.1
<tb><SEP> Samples <SEP> N <SEP> - <SEP> 8.56 <SEP>
<tb><SEP> Sample <SEP> P <SEP> - <SEP> - <SEP> 8.03
<tb><SEP> Constituent <SEP> mineral <SEP> 5.20 <SEP> 5.20 <SEP> 5.20
<tb><SEP> Oil <SEP> 37.90 <SEP> 38.15 <SEP> 38.38
<tb><SEP> Fat <SEP> 47.80 <SEP> 48.09 <SEP> 48.39
<tb><SEP> 100.00 <SEP> 100.00 <SEP> 100.00
<Tb>
The compositions D, E and F are in the form of a creamy brown paste, spreadable with a brush; they contain 5% of ethephon equivalent in the form of monoethanolamine partial salt.

 In the case where it is desired to have a composition in accordance with the invention which comprises both the immediately available ethephon and the gradually released ethephon, it is possible to include a composition according to the invention. an aqueous ethephon formulation according to the prior art.

 The subject of the invention is therefore also phytosanitary compositions comprising at least 50% by weight of the phytosanitary composition in accordance with the invention and at most 50% by weight of an aqueous ethephon formulation, the percentages being expressed relative to the total mass of the composition.

 In practice, one can proceed as follows.

 On the one hand, 25 g of an ethephon-based aqueous product R according to the prior art are prepared, the 25 g of the product in question consisting of 3.50 g of an aqueous solution of ethephon at 1000 g / l, 0.40 g of RHODOPOL B23 and 21.10 g of water.

 On the other hand, 75 g of a composition G according to the invention are prepared by proceeding according to the indications given above, these 75 g consisting of - 10.40 g of the same ethephon solution, - 6.90 g of the aforesaid mineral constituent, 25.50 g of the aforesaid oil, 32.20 g of the aforesaid fat.

 R and G products are in the form of pasty semi-finished products.

 The 25 g of product R and the 75 g of composition G are intimately mixed.

 An unctuous brown paste, spreadable with a brush and containing 10% by weight of ethephon is obtained, of which a quarter is available immediately and the remaining three quarters are available to spread over time.

 In the following comparative examples, the retardation effect and the resistance to water runoff were measured in the case of compositions A, B and C, on the one hand, and in the case of compositions according to the prior art, 'somewhere else.

1. COMPARATIVE EXAMPLE RELATING TO THE DELAY EFFECT.

 To measure the delay effect, the ethephon paste is placed in a diffusion cell immersed in water.

 The ethephon liberated as a function of the residence time is measured by alkalimetric titration.

 The equipment used, which is made of borosilicate glass, cellulose or rubber plastic, is carefully cleaned beforehand and rinsed with deionized water.

 This apparatus essentially comprises a diffusion cell consisting of a polystyrene petri dish whose bottom has an inner diameter of 85 mm, the lid has an inner diameter of 90 mm and the inner height is 10 mm.

 The lid is hollowed out with a disk about 70 mm in diameter and the orifice thus created is closed off with the aid of a porous membrane of cotton cellulose paper, for example DURIEUX S 11 filtration paper. mm diameter and 0.16 mm thick, loose texture, fast filtration, 10% retention, and calcining residue <0.01%.

 The bottom of the box is ballasted with a sufficient mass of alumina balls to avoid floating and then loaded with exactly 20 g of 5% ethephon paste spread in regular layer.

 Three experiments are carried out using 20 g of compositions A, B and C, respectively.

 The box is closed with the cover provided with the paper membrane. The assembly is held at the bottom of a borosilicate glass beaker of 1 l (internal diameter: 100 mm, height: 140 mm) containing 500 g of demineralized water.

 At regular time intervals, the aqueous phase is gently but carefully mixed, 10 ml measured are taken exactly, and then it is diluted with about 30 ml of demineralized water; 3 drops of a hydroalcoholic solution of bromocresol green which is a colored indicator of equivalent point exhibiting a change in coloration from pale yellow to intense blue in the vicinity of pH equal to 4.

 The aforesaid samples are determined by means of a liquor titrated aqueous centinormal soda.

The control used is a 5% aqueous paste of ethephon with no delay effect, marketed by the
Applicant Company (the dye was omitted for the convenience of the assay); this control is treated as compositions A, B and C according to the invention, both for calibration and for release measurements.

In Table IV, the results recorded using the control and the compositions A, B and
C, namely the percentages of ethephon released (as a percentage of the totality of the ethephon contained in a given sample) as a function of time.

TABLE IV

% OF ETHEPHON <SEP> FREE <SEP> SPONTANEOUSLY
<tb> Experience <SEP> BY <SEP> SIMPLE <SEP> MACERATION <SEP> AQUEOUSAPTER <SEP> (duration <SEP> in <SEP> days)
<tb> with
<tb> 0 <SEP> 0.125 <SEP> 0.25 <SEP> 1 <SEP> 2 <SEP> 3 <SEP> 5 <SEP> 8 <SEP> 12 <SEP> 16 <SEP> 20 <SEP> 23 <SEP> 27 <SEP> 33 <SEP> 37 <SEP> 57 <SEP> (*)
<tb> Control <SEP> 0 <SEP> 5.56 <SEP> 28.63 <SEP> 71.52 <SEP> 91.38 <SEP> 94.04 <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP>
Compo0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 99.8
<tb> sition <SEP> A
<tb> Compo0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0.15 <SEP> - <SEP> 5.07 <SEP> 8.81 <SEP> 10.4 <SEP> 12.95 <SEP> 20.38 <SEP> 26.23 <SEP> 30.91 <SEP> 39.22 <SEP> 45.75 <SEP> 65.29 <SEP> sition <SEP> B
<tb> Compo0 <SEP> - <SEP> - <SEP> 0.07 <SEP> 0.34 <SEP> - <SEP> 10.10 <SEP> 13.56 <SEP> 21.1 <SEP> 27.74 <SEP> 34.81 <SEP> 38.60 <SEP> 42.00 <SEP> 54.25 <SEP> 56.87 <SE> 78.45 <SE> 94.5
<tb> sition <SEP> C
<tb> (*) It was verified that Composition A contains substantially all the ethephon after 57 days; to do this, it was forced trituration extraction of the dough placed in the Petri dish and perform the assay. This verification was repeated with the composition C, and the balance was made of the ethephon liberated added to that still present and freed by trituration.

 Examination of the results summarized in Table IV shows that compositions A, B and C release the active ingredient in a significantly more progressive manner than the control and according to a kinetics that can be controlled; in other words, by judiciously choosing the proportions of the various constituents, the delay effect can be varied at will, the latter being able, as shown by the composition A, to tend towards infinity.

 The delay effect in each experiment can be quantified by reporting the time required to release 50% of the active ingredient in the case of compositions A, B and C and the control.

 The results as well as the "half-release" times are shown in Table V.

TABLE V

<tb><SEP> Composition <SEP> A <SEP> Composition <SEP> B <SEP> | <SEP> Composition <SEP> C <SEP> | <SEP> Witness
<tb> Time <SEP> of
<tb> half-release <SEP> Oc <SEP> 46 <SEP> 34 <SEP> 0.5
<tb> (in <SEP> days)
<tb> Effect <SEP> delay
<tb> relative <SEP> by <SEP> rap- <SEP> Oc <SEP> 92 <SEP> 68
<tb> port <SEP> to <SEP> witness
<Tb>
Under the arbitrary conditions adopted (in vitro method by aqueous maceration), the compositions in accordance with the invention show a clear delay effect compared with the prior aqueous formulation.

2. COMPARATIVE EXAMPLE RELATING TO RESISTANCE TO RUISSEL
WATER, OR LEACHING.

 Two pastes with a 5% ethephon content were compared, under the same standard conditions, with respect to their behavior under spraying under running water, one of the pastes (prior art) being constituted by a paste aqueous solution marketed by the applicant company, the other being constituted by the composition C.

 A sample of approximately 1 g of paste is spread as evenly as possible on a 76 x 26 mm glass slide, which corresponds to approximately 0.5 mg / mm 2.

 The test piece thus formed is placed under a stream of running water having a temperature of approximately 200 ° C. and a flow rate of approximately 10 ml / s, said test piece forming an angle of approximately 20 ° to the normal to trickle of water.

 The length of resistance to the detachment of the dough is measured.

 The recorded results are shown in Table VI.

TABLE VI

<SEP> Products <SEP> tested <SEP> Duration <SEP> of <SEP> test <SEP> Observations
<tb><SEP> Approximately <SEP> 90% <SEP> of <SEP> The <SEP> Quantity <SEP> of
<tb><SEP> paste <SEP> initial <SEP> have <SEP> el <SEP> mechanized
Product <SEP> according to
<tb> 30 <SEP> s <SEP> simply <SEP> off the hook <SEP> and
<tb><SEP> previous art <SEP>
<tb><SEP> trained <SEP> by <SEP> the <SEP> current <SEP> of water
<tb><SEP> Appearance <SEP> of <SEP> specimen
<tb> Composition <SEP> C <SEP> 120 <SEP> s
<tb><SEP> practically <SEP> unchanged
<Tb>
From these results, it appears that, under the conditions of the test, the hydrophobic paste according to the invention is substantially more resistant to leaching than the aqueous gel according to the prior art.

Claims (8)

 A phytosanitary composition characterized in that it comprises a water-soluble active ingredient selected from the group consisting of herbicidal substances and plant hormones dispersed in a carrier consisting of not more than about 33% by weight of a constituent  mineral, powdery and absorbent  more than 15% by weight and 90% of which  constitutive particles have a particle size less than  than about 40 pm, - for not more than about 66% by weight of a hydro product  selected from the group consisting of oils and  fats of mineral, vegetable or animal origin.  2. Phytosanitary composition according to claim 1, characterized in that it comprises: - as an active ingredient, from 2 to 30% by weight,  preferably from 5 to 20% by weight, based on the mass  total composition, eventually etherphon  partially neutralized, - as a mineral constituent, powdered and absorbed  bant, from 0.4 to 25%, preferably from 4 to 15% by weight  relative to the total mass of the composition,  silica and / or clay powder with 90% of the particles  constituents have a particle size less than about 4 ohm, - as a hydrophobic product, from 7 to 60%, preferably  35 to 45% of a mineral oil with  pre-dominant paraffinic and 7 to 60%, preferably  from 40 to 60% by weight relative to the total mass of the  composition, a fat or vaseline firm type  petrolatum and - optionally less than 1% by weight per  relative to the total mass of the composition, an agent  rheological.  3. phytosanitary composition according to claim 2, characterized in that the etherphon is used in the form of an aqueous solution containing in particular 400 to 1000 g / l of active ingredient consisting of ethephon technical which is a waxy white solid melting at about 74-750C.  4. Phytosanitary composition according to one of claims 2 and 3, characterized by the fact  the silica powder is chosen from micronised, precipitated, pyrogenic, surface-treated silicas of natural or synthetic origin, this silica powder being able to be that marketed by the DEGUSSA company under the brand name AEROSIL 2OO and  that the clay powder consists essentially of metal aluminosilicates (for example of the Fe-Mg type) obtained from sedimentary rocks consisting essentially of phyllitous or fibrous minerals.  5. Phytosanitary composition according to one of claims 2 to 4, characterized by the fact  that the predominant paraffinic mineral oil is that marketed by FINA under the trademark F 9805 # and  - That the fat or vaseline firm is that marketed by Shell Company under the name Petrolatum S3285.  6. phytosanitary composition according to one of claims 2 to 5, characterized in that the rheological agent is constituted by one or more of the biopolymers marketed by RHÔNE-POULENC under the brand RH0DOPO.  7. Phytosanitary composition according to one of Claims 2 to 6, characterized in that the etherphon has been neutralized by using a neutralizing agent chosen from the group comprising hydroxides, oxides, carbonates, alkali metal or alkaline earth metal bicarbonates, alkanolamines, optionally oxyalkylenated fatty amines and basic amides.  8. A phytosanitary composition characterized in that it comprises at least 50% by weight of a composition according to one of claims 2 to 7 and at most 50% by weight of an aqueous formulation of ethephon.