FR2473272A1 - EXPANDED BUT PARTICLES WITH INCREASED ABSORPTION CAPACITY, PROCESS FOR PREPARING THE SAME, AND PESTICIDE COMPOSITION CONTAINING THE SAME - Google Patents

Abstract

The present invention relates to expanded corn particles and a process for their preparation. The expanded particles have an increased absorption power and have been found useful for the formulation of insecticide baits, in particular baits for ants of the genus Solenopsis, and other compositions for agricultural use.

Description

The present invention relates to expanded particles. from

grains of corn on the cob (called

  hereinafter "corn particles"), as well as a process for pre-

  paration of said particles. The invention is more particularly

  especially for expanded particles which present

  have increased absorption capacity and have

  useful in the formulation of insecticidal baits, in particular

bait for ants of the genus Solenopsis, and other com

  agricultural uses such as pesticide formulations, food additives and the like. The invention relates to

  even more specifically insecticide baits and

  very agricultural compositions using said particles

of but expanded.

  We know corn particles of different shapes and dimensions. These particles are incorporated into

various compositions as carriers for biological compounds

  only active in agriculture. Corn particles having an apparent specific gravity of approximately 384 g / l to approximately 561 g / l are generally satisfactory for the absorption of liquid formulations, except that the absorption capacity of said liquid formulations is rather limited and does not exceed about 15% by weight of the total of the composition. The compositions having a

  higher proportion of absorbed liquid appear to be hu-

  mides and do not flow freely, but are on the contrary

re sticky.

It has been found, in accordance with the present invention,

  that the corn particles can be expanded in a way

re to present an apparent specific mass of approximately 280 g / l to approximately 353 g / l and, in addition, an ability to absorb increased quantities of liquids, to give compositions containing approximately 20% to approximately 30% by weight of these liquids relative to the weight of the composition,

  which corresponds to about 25% to 43% by weight compared to

  the initial weight of the particles. The liquids envisaged

  managed in this memo may have only one cons-

constituting or constituting a formulation with two or more constituents as in the case for example of the solution -2-

  an insecticide in an edible carrier such as oil

the soybean. This product can deliver more active ingredients than the initial unexpanded particles,

  in a more efficient and / or more economical way.

In general, in accordance with the process of the present invention, the corn particles are heated to a temperature of about 1050 C to about 1350 C, at a pressure higher than atmospheric pressure, and in the presence of steam. saturated water or water vapor and water, in an autoclave, for a period of about 10 minutes to about 60 minutes. The water vapor is then rapidly released into the atmosphere and the expanded particles thus obtained are dried, if necessary, and cooled to room temperature. Although the above process is particularly suitable when using industrial autoclaves, you can also use

using other devices allowing rapid heating

  under pressure and in the presence of saturated steam or steam and water, decompression and drying

  (for example an extrusion device).

So, for example, corn particles from 0.42 to 2.0 mm, having an apparent specific mass

  from approximately 384 g / l to approximately 561 g / l are pre-heated

  saturated steam or steam and water at a temperature of about 1050 C to about 1300 C and below

  a pressure from about 110 kPa to about 280 kPa during

  about 10 to 60 minutes. The steam is then released into

the atmosphere, the expanded particles are dried, if ne-

stop, and cooled to room temperature to

  give the expanded and highly absorbent corn particles

  bants of the present invention, having a specific mass

apparent specificity of approximately 280 g / l to approximately 353 g / 1.

Also good results can be

  carefully obtained by heating the corn particles during

a relatively short duration in the temperature interval

maximum aforementioned maximum or in the vicinity thereof, then in

slowly expelling the water vapor to obtain an interval

  the lowest temperature and pressure and then in -3 - keeping said particles in this temperature and pressure range for a short time, after which the particles are dried and cooled.

but expanded and highly absorbent thus obtained.

  The particles thus prepared can absorb

  increased amounts of liquids to give compounds

  containing about 20% to about 30% by weight of-

  said liquids relative to the weight of said compositions.

As specified above, the corn particles

and in particular the particles of maize which were ex-

bandaged by the process of the present invention,

are good for bait preparation, when used

as carriers of insecticides acting as a

  stomach sounds, such as the insecticide of formula (I) N

C NH-N = C (CH = CH CF

CH3'3

CH7 CF3) 2

NOT

H (I)

  described in US Patent No. 4,163,102, the method of using this insecticide being described in United States Patent No. 4,087,525 and in US Patent Application No. 004,645, granted the

  October 19, 1979. Reference may be made to these patents.

  This product is tetrahydro-5-, 5-dimethyl-2 (1H) -

pyrimidinone-f3- [4- (trifluoromethyl) phenyl 1- 1-2- [4- (tri-

  fluoromethyl) phenyl] -ethenyli-2-propenylidene} hydrazone. The baits thus prepared are effective against insects comprising masticatory buccal parts (orthopteran insects such as cockroaches or cockroaches, grasshoppers, crickets and isopteran insects such as termites). They are also effective in controlling ants of the genus Solenopsis, such as the southern ant

of the genus Solenopsis (Solenopsis xyloni), the black ant im-

  litter of the genus Solenopsis (Solenopsis richteri) and the four-

mi red imported from the genus Solenopsis (Solenopsis invicta).

They are also effective in controlling ants such as the big-headed ant (Pheidole megacephala) and the - 4 -

  Argentine ant, Iridomyrmax humilis, which are the pre-

dominant daters in grapefruit plantations

  and sugar cane, as well as in the fight against many

  breuse species of ants that are classified: in the general category of domestic ants. Ants are predators that seriously threaten the economy and public health. The serious problems created by ants of the genus Solenopsis are the bites made on human beings and living species, the damage caused to

  plants on which said ants feed, in particular

  binder to seedlings or young plants and to seeds in the process of germination, damage caused to agricultural equipment which is invaded by ovipositive ants, crop losses and the refusal of workers to enter the

  infested fields to cultivate and harvest crops.

Ants invade houses, crawl on food, carry particles of it into their nests and also cause damage by establishing them

  in the woodwork of houses and other constructions

carrying wood.

  We can fight against these predators by means of

treated pasta which is distributed in infested areas or in the vicinity thereof, such as in meadows,

  livestock pens or other locations in the

which one wishes to get rid of the ants, these baits being thus made available for the workers who transport the treated bait to the colony where it is consumed by the queens and the young workers, which leads to their destruction. In practice, the effective amount of compound of formula (I) for destroying ants of the genus Solenopsis and / or protecting crops is generally from about 1.25 g / ha to 75.0 g / ha and preferably from 2, 5 g / ha to 37.5 g / ha;

  moreover, the effective amount of this compound to destroy

re domestic ants and / or other insects that can be controlled with bait is about 0.0625% at

  % by weight and preferably 0.125% to 2.0% by weight.

  The baits can be prepared by mixing, for example, an insecticide with vegetable oils such as soybean oil, using or not using a lure as

  lecithin. The composition thus obtained is then absorbed

open on the expanded particles of corn but which are distributed in the zone of the colony or infested zone. The use of these baits has a particular advantage - since such a distribution method presents little or no danger to non-target living beings which can frequent the

infested area.

The invention will now be further illustrated

  by the examples below, given without limitation.

EXAMPLE 1

Preparation of expanded corn particles Process

Particles of goat are treated in an autoclave

  ve, under a pressure of 210 kPa (1210 C), for 30 minutes

tes, in the presence of saturated steam. The pressure is then lowered by slowly releasing steam into the atmosphere until the internal temperature drops to 1000 C. The autoclave is maintained at approximately 157 kPa for an additional period of 10 minutes, then the pressure is

  quickly released and the contents are dried for 30 minutes

while it is still in the autoclave.

Three samples were prepared, in accordance with the above process, using 0.42 to 2.00 mm corn particles, having an apparent specific gravity of 466.1 g / l, as follows:

  1. 453 g of particles as received.

2. 453 g of particles with an addition of 1% by weight of water; and 3.453 g of particles, with an addition of 5%

by weight of water (22.7 g).

  After expansion according to the above process, the samples have a specific mass range

  apparent from 309.2 g / 1 to 318.6 g / l.

The absorption capacity of the samples is evaluated by preparing mixtures of said particles with soybean oil, these mixtures containing%, 25% and 30% by weight of soybean oil respectively. Mixtures containing 20 to 25% by weight of soybean oil flow freely and are dry. Mixtures containing 30% by weight of oil are somewhat damp and do not flow

not freely.

EXAMPLE 2

Preparation of expanded particles of corn

  Two samples of corn particles (approxi-

  ron 181 kg each), which differ only in the distribution

particle size distribution, are expanded according to

  the process of Example 1 above.

  The particle size distribution, the

apparent specific mass and oil absorption capacity

the soybean particles thus obtained are expanded

  prepared for those of the respective initial substances. The results obtained are summarized in Tables Ia and Ib below.

EXAMPLE 3

  Prep'arat'i'o'n 'of p'articules'.de' but exp'ans'é'es By operating according to the process of Example 1, two samples are prepared using particles

from 0.42 to 2.0 mm but with a specific mass

that apparent of 464.5 +32 g / l.

  ' at. a sample is heated for 10 minutes under a pressure

  sion of 210 kPa at 121 C, in the presence of saturated steam, which gives expanded granules having a

  apparent specific mass of 323.6 g / l.

b. a sample is heated for 10 minutes at 135 kPa, at 108 C, in the presence of saturated steam, which

  gives expanded granules having a specific mass

apparent specificity of 325.2 g / 1.

4 EXAMPLE 4

  Evaluation of the effect of modifications of the expansion process By operating according to example 1 above, a certain number of tests are carried out using corn particles of 0, 42 to 2.0 mm which have an apparent specific mass of 464.5 32 g / 1, as follows: 7-

TABLE Ia

  Echan-Tmis Distribution (in%) Specific gravity before till after apparent in mm before after + 0.84 42.8 64.7 465.5 g / 1,323.6 g / 1

+ 0.59 36.3 25.2

A + 0.42 17.9 8.8

-0.42 2.8 0.8

+0.84 89.4 96.8 488.6 g / 1,410.1 g / 1

+0.59 10.1 3.1

B B + 0.42 0.3 traces

-0.42 0.1 -

TABLE Ib

  Summary of absorption data for Soybean oil Echan-% in Aspect of mixtures prepared from the weight of the oil particles before expansion after expansion slightly oily,

flowing free

  oily, not draining, flowing freely A 25 sec, free flowing slightly moist very oily, not flowing very oily, not dry, flowing not flowing freely B 25 slightly damp

wet, do not drain

not

  Summary of data on the distribution of dimensions

sions, of particles and the apparent specific mass

-2473272

- 8 - a. a sample is autoclaved for 10 minutes, at a pressure of 210 kPa and at 121 C, with saturated steam, then the autoclave is then slowly brought back

  at atmospheric pressure. The pressure is then im-

  temporarily brought to 210 kPa (at 121 C) and maintained at this value for an additional period of 10 minutes. The autoclave is then quickly returned to the

atmospheric pressure and the sample is dried during

for 15 minutes.

  lO b. as in paragraph a except that one operates under a pressure of 136 kPa and at 108 C. c. a sample is autoclaved for 10 minutes under a pressure of 210 kPa, at 121 C, with saturated steam; the autoclave is then quickly returned to the

  atmospheric pressure and the sample is dried.

  d. as in paragraph c except that the pressure is 136 kPa and the temperature 108 C.

  e. as in paragraph c except that after quick-

  put the autoclave back to atmospheric pressure,

the sample is not dried.

  f. as in paragraph d except that after quick-

  put the autoclave back to atmospheric pressure,

the sample is not dried.

We then determine the specific masses ap-

  parent, moisture content and oil absorption capacity of the samples. The results thus obtained are

summarized in Table II.

- 9 -

TABLE II

  Physical characteristics of the samples obtained by the previous tests

Mass% of humidity

  Sample specificity (in% of absorbed oil; apparent weight) aspect of the sample

______. g / i ....

  A 318.8 7.9 20; very slightly today

  smooth, flowing freely; slightly oily, free flowing

  B 336.4 7.3 20; very slightly today

  smooth, flowing freely; slightly oily, free flowing

C 323.6 6.1 20; very slightly today

  smooth, flowing freely; slightly oily, free flowing

  D 325.2 3.6 20; very slightly today

smooth, flowing freely; slightly oily, ________ flowing freely

  E 307.6 7.1 20; very slightly today

smooth, flowing freely; slightly oily, free flowing

  F 315.6 7.7 20; very slightly today--

smooth, flowing freely; slightly oily, free flowing

- 10 -

R E E N D I C A T I.0 N S

  1. Process for the preparation of expanded maize particles having a specific mass range

  apparent of 280 g / l. at 353 g / l and a capacity to absorb

tion of liquids ranging from 25 to 43% by weight relative to said expanded particles, characterized in that it comprises the stages consisting in heating corn particles having an interval of apparent specific masses from 448 g / l to 561 g / l , in a temperature range of 105 to 130 C, at a pressure higher than atmospheric pressure, in the presence of saturated steam, for a period of 10 to 60 minutes, to then release the steam in the atmosphere and to cool

  these particles down to room temperature.

2. Method according to claim 1, characterized in that the particles R 121 C are heated in the presence of saturated steam for 30 minutes, this is released.

water vapor in the atmosphere to decrease the temperature

  the particles thus treated are heated for

  10 minutes at 113 C, residual vapor is released if necessary.

  tually present and the particles are cooled to

Room temperature.

  3. Method according to claim 1, characterized in that the above-mentioned particles are first heated to 120 - 122 C, under a pressure of 200 kPa to 220 kPa, then they are heated to 110 C - 115 C under a pressure of

kPa to 160 kPa.

  4. Method according to claim 1, characterized in that the aforementioned particles are firstly heated to 121 C, under a pressure of 210 kPa, for a period

30 minutes, then at 113 C for 10 minutes.

  5. Characterized but expanded corn particles

  in that they have a specific mass interval

  ques apparent from 280 g / l to 353 g / l and a capacity of-

sorption of liquids ranging from 25% to 43%, by weight, relative

to said particles.

- he -

  6. Pesticide composition, characterized in that it consists of particles according to claim 5, which

have absorbed soybean oil containing, in the dis-

  under 1.25% to 2.5%, by weight, of tetrahydro-5,5-dimethyl-

2- (1H) -pyrimidinone-13- [4- (trifluoromethyl) phenyl] -1- {2-

  [4- (trifl.uoromethyl) phenyl -ethenylj -2-propenylidene hydra-

zone, compared to this oil.