Particles containing pheromones and production process

Abstract

The present invention is directed towards microparticles consisting of a solid shell made of polymer, in particular an acrylic polymer, surrounding a core comprising a mixture of oil and wax and also pheromone. The present invention is also directed towards a production process and the use of an aqueous suspension of such microparticles containing pheromones comprising fatty chains, such as lepidopteran pheromones, and which are capable of releasing the pheromones in a sustained manner.

Claims

1. Particles comprising a solid shell surrounding a core, wherein: the solid shell comprises at least one acrylic copolymer, the core comprises a mixture of wax, oil and pheromone, the core represents 90-99% by weight of the particles, wherein the acrylic copolymer of the solid shell is selected from HASE-type copolymers and wherein it contains: between 30% and 40% by weight of methacrylic acid, between 45% and 60% by weight of ethyl acrylate, between 5% and 20% by weight of a macromonomer having the general formula (I): ##STR00003## where m is an integer between 1 and 40, and where R is a hydrophobic carbon group having the general formula C.sub.nH.sub.2n+1 wherein n is an integer between 9 and 25.

2. The particles according to claim 1, wherein the acrylic copolymer has carboxylate functions that are neutralized at a rate between 50% and 100%.

3. The particles according to claim 1 wherein the core contains: 10% to 90% by weight of wax, 10% to 90% by weight of oil, 0.1% to 25% by weight of pheromone, 0 to 0.8% by weight, of stabilizer.

4. The particles according to claim 1 wherein the wax is selected from the group consisting of beeswax, lanolin wax and Chinese insect waxes; rice wax, carnauba wax, candelilla wax, jojoba wax, ouricury wax, esparto wax, cork fiber wax, sugar cane wax, Japanese wax and sumac wax, montan wax, microcrystalline waxes and mixtures thereof.

5. The particles according to claim 1 where in the oil according to the invention is selected from the group consisting of sunflower oil, peanut oil, soybean oil, rapeseed oil, corn oil, olive oil, grape oil, walnut oil, linseed oil, palm oil, coconut oil, argan oil, avocado oil, almond oil, hazel nut oil, pistachio oil, rice oil, cotton seed oil, wheat germ oil, sesame oil and mixtures thereof.

6. The particles according to claim 3, wherein the stabilizer is selected from the group consisting of n-butyl-4-hydroxybenzoate (BHB), tocopherol, ter-butyl-hydroquinone (TBH), n-propyl-gallate (PG), t-butyl-hydroxyanisole (BHA), methyl para-hydroxybenzoate (MIHB), N,N-diethyl-toluamide (DT), t-butyl-hydroxy-toluene (BHT) and -thioglycerin (TG), nitroxides and alkoxyamines and mixtures thereof.

7. The particles according to claim 1, wherein the pheromone is selected from lepidopteran sex pheromones.

8. An aqueous suspension of particles according to claim 1 wherein the suspension contains between 1% and 70% by weight of particles, and has a pH between 2 and 7.

9. A process for preparing a suspension of particles according to claim 8 comprising the following steps: a) Prepare a fatty phase comprising oil, wax and pheromone, and optionally one or more stabilizers, b) Heat the fatty phase to a temperature above the melting point of the wax, c) Prepare an aqueous solution comprising the acrylic polymer, having a pH between 7.5 and 10 and heated to a temperature similar to that of the fatty phase, d) Mix the fatty phase in the aqueous solution to form a dispersion of fatty-phase droplets in a continuous aqueous phase, e) Acidify at a pH between 2 and 7, in order to solidity the acrylic polymer.

10. Method for spraying foliage comprising the application of particles according to claim 1 onto foliage in need thereof.

11. Method for luring lepidopterans according to a trapping protocol or a sexual confusion protocol in crops such as grapevine, field crops, garden market crops, fruit trees or ornamental trees comprising applying particles according to claim 1 into said crops in need thereof.

12. A process for protecting an agricultural plot, in particular a cultivated agricultural plot, against lepidopterans comprising applying a composition comprising particles according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1, FIG. 2 and FIG. 3 represent photographs obtained with a scanning electron microscope and are an illustration of the dimensions of the particles obtained: a few microns in this example.

Example 2

Preparation of European Grapevine Moth (Lobesia Botrana) Pheromone Capsules

(2) The preparation of European grapevine moth pheromone capsules was carried out according to the general procedure above with the amounts of reagents presented in the following table.

(3) TABLE-US-00004 Components of the formulation Test 7 Aqueous HASE 1 3.7 g phase H.sub.2O 30.9 g NaOH (10%) 1.4 g Solution 1 Beeswax 7.8 g Sunflower oil 22.9 g Pheromone 1.5 g Solution 2 H.sub.3PO4 (4%) 3.2 g

Example 3

Preparation of a Vaporizable Suspension of European Grapevine Moth Pheromone Capsules

(4) To a suspension of 2 g of capsules containing the European grapevine moth pheromone, derived from example 2, is added 30 g of water. The fluid preparation is placed in a bottle provided with a manual sprayer. This particle suspension can be vaporized in fine droplets and thus form a thin film.

Example 4

Release Kinetics

(5) The release kinetics of the vine moth pheromone capsule preparation tests 1, 2 and 3 described in example 1 are presented below.

(6) TABLE-US-00005 Residual pheromone content (mg) Time (days) Test 1 Test 2 Test 3 0 62.8 31.4 15.7 3 42.0 24.6 14.9 7 13.9 10 30.3 19.4 14 26.4 17.4 12.1 17 15.6 12.9 21 22.2 9.8 9.9 24 22.4 8.5 Test 1 Test 2 Test 3 Average daily release rate (mg) 1.75 0.9 0.28

(7) These examples show that the capsules produced in example 1 make it possible to release the pheromone over long periods with a daily rate controlled by the ratio of the pheromone to the mass of the capsule.

(8) Likewise, the pheromone release of the capsules derived from tests 4, 5 and 6 was carried out in a controlled manner with daily rates between 0.5 and 2 mg/day of pheromone.

Example 5

Preparation of a Suspension of Mediterranean Corn Borer Pheromone Particles

(9) The preparation of a suspension of Mediterranean corn borer pheromone was carried out according to the general procedure above with the amounts of reagents presented below.

(10) TABLE-US-00006 Components of the formulation Test 8 Test 9 Test 10 Aqueous HASE 1 3.7 g 6.63 132.74 phase H.sub.2O 30.9 g 27.9 558.58 NaOH (10%) 1.4 g 2.56 51.32 Solution 1 Beeswax 7.8 g 13.9 278.94 Sunflower oil 22.9 g 33.2 664.07 Pheromone 1.5 g 10 200 Solution 2 H.sub.3PO4 (4%) 3.2 g 5.7 113.98 Suspension total mass 56.5 100 2000

Example 6

Coating of Particles Obtained in Example 5 and Release of the Pheromone

(11) The suspension of particles 10 was deposited on paperboard pads.

(12) The table below represents the residual amounts of the two compounds, (11Z)-hexadecenyl acetate/(11Z)-hexadecenol (9:1), of the pheromonal mixture in the particle coating over time.

(13) TABLE-US-00007 MAJORITY COMPOUND MINORITY COMPOUND Time (days) Amount of pheromone Amount of pheromone 0 360.0 40.0 3 297.1 36.2 8 312.5 38.1 13 335.3 35.9 20 316.2 37.9 24 319.2 38.0 34 323.0 38.9 38 290.1 34.7 45 245.0 29.2

(14) These data correspond to an average daily rate of the majority component of 1.6 mg/day and of the minority component of 0.15 mg/day, and show that beyond 45 days, the release of the two compounds is still effective. Moreover, it should be noted that the ratio of the two compounds present remains virtually constant during the study.

Example 7

Preparation of Pine Processionary Moth Pheromone Capsules

(15) The preparation of a suspension of pine processionary moth pheromone was carried out according to the general procedure above with the amounts of reagents presented below.

(16) TABLE-US-00008 Components of the formulation Example 1 Aqueous HASE 1 0.94 g phase H.sub.2O 7.74 g NaOH (10%) 0.36 g Solution 1 Beeswax 1.92 g Sunflower oil 5.62 g Pheromone 0.23 g

(17) The table below represents the residual amount of pheromone in the particle matrix over time.

(18) TABLE-US-00009 Amount of residual Duration (days) pheromone (mg) 1 13.6 11 13.6 14 13.3 18 13.3 30 13.1

(19) This study shows that with a 3% load of processionary pheromone, the release rate is slow and makes it possible to propose forest treatment systems that are active for 9 months.

Example 8

Deposition of a Capsule Suspension by Means of a Plastic Syringe

(20) Capsules containing pine processionary pheromone were packaged into syringes. Each syringe contains an amount of pheromone that can be deposited on a substrate in a processionary caterpillar trap. This provides a simple model for depositing pheromone in a trap.