DE1619865A1 - Use of a finely divided, amorphous silica with a high structure as a carrier filler for active ingredients - Google Patents

Description

GERMAN GOLD AND SILVER SCIIEIDEANSTALT FORMERLY ROESSLER

Frankfurt / Main, Weissfrauens.tr. 9 1619865

Use of a finely divided, amorphous silica with a high Structure as a carrier filler for active ingredients.

The invention relates to the use of finely divided, amorphous Silicas with a high structure as carrier fillers for liquid ", pasty or waxy active ingredients, especially in crop protection, Pest control and livestock feed additives.

Highly dispersed, precipitated silicas and silicates have been used since Used as a carrier filler for pesticides for more than 15 years. In the course of constant further development, a number of new silica grades have been added for this area of application in recent years specific properties on the market.

When using highly dispersed silicas as a carrier filler in highly concentrated pesticide formulations, their active ingredients due to certain physico-chemical properties high Make demands on the wearer, it comes down to high absorbency for liquid, pasty and waxy active ingredients of all kinds or their highly concentrated solution forms, extremely good The floating behavior of wettable powders in the spray liquid (high Fine division) good compatibility with all pesticides (neutral pH value) and loosening up those that tend to agglomerate powdery products (low bulk density).

Pest control and crop protection agents are essentially used handled in two forms, as wettable powders and as dust concentrates:

Wettable powders consist of the following components: pesticidal active ingredient, carrier filler, dispersing and wetting agent and, depending on the type of formulation, other additives. After 'thorough premixing of these constituents , coarse grinding follows, followed by fine grinding.

T09812 / T70 8

161.P865

As a pesticide carrier prevent silicas with High Satigvermögen · (high Oelabsorptionszahl) adhesion of the grinding units and 'blocking of the mills, so that a trouble-free grinding process is guaranteed. "The suspension properties of wettable powders in the scheduled spray mixture must be guaranteed" the dispersed powder must gleichinässig distributed and must practically not settle, which can be achieved through a high degree of fineness. By using precipitated silicas of low bulk density, the dusty products that tend to agglomerate are loosened, so that improved storage stability and thus preservation of the active substance is guaranteed The neutral pH of the carrier silica means that it is compatible with most pesticides.

Dust concentrates, on the other hand, only consist of active ingredient and filler, The formulation is similar to that of wettable powders. It does not happen a fine grinding, as these products after blending can be applied in dust form with cheap mineral fillers such as kaolin, talc or dolomite.

Silicas, which, due to their high pumping speed and high "Oe!" are also suitable as carrier fillers for liquid, pasty and waxy active ingredients of all kinds, e.g. also in feed additives,

Various types of silica are known which differ in terms of on their dibutyl phthalate (-DBP) or oil absorption of differentiate other pebbles 1 acids (e.g. xerogels). It deals This includes wet-precipitated silicas or silica gels to which a special variant of the drying process SiO_- containing substances, their "structure" or DDP absorption is particularly high:

a) AorogeIo

b) Silicas, their intermiscellare liquid before drying from organic solvents or mixtures thereof Solvent with water consists and

c) spray-dried silicas.

10 9817/1708

- 3 - ■■■■■■■

While the silicas belonging to a) and b) due to their high manufacturing costs as carrier fillers for all active ingredients Spray-dried silicas can hardly be used in addition to the usual types of silica due to their significantly higher "structure" and the associated high absorbency increasingly used as carrier fillers for liquid active ingredients . Although spray-dried silicas are superior to normally dried silicas in terms of their absorbency, the use of expensive equipment required for spray drying and the increased drying energy requirement have an unrestricted effect Use as a carrier filler for pesticides and other substances strongly opposed.

The aim of the invention is the use of finely divided, amorphous Silicas with a high structure or high DBP or oil number as carrier fillers for liquid, pasty or waxy Active ingredients of all kinds, but especially for pesticides and cattle feed ingredients, through which the previously described Disadvantages are avoided.

The characteristic feature of the invention can be seen in the fact that finely divided, wet-precipitated silicas with a high structure, determined by the dibutyl phthalate absorption number of 2.2 to 3 ml / g, and a grain size limit of less than 7 ti, determined according to Bahco analysis particle size distribution of jteßjc ^ bxue 57 wt.% proportions by mass of "C 2 μ particle size be used.

The silica to be used according to the invention can in the manner be prepared that during the precipitation of silica gels or silicas from alkali silicate solutions with acid through continuous action of certain, sufficiently large shear forces the growth of the secondary particles formed from primary particles is influenced in such a way that a certain size of the Secondary particles cannot be exceeded during their formation. For carrying out such a process step

/ and turbo devices are suitable dispersers; especially continuously working

Pumps with high flow rates.

.. ',' ■■ _ 4 10 9817/1708

For precipitation, 73 liters of hot water and 5.25 liters of soda water glass (density: 1.35 g / cm; module SiO ₂ : Na_0 = 3.3o) are added

₂ _

Stirring heated to 85 ° C. During the following 90 minutes, sodium waterglass (d = 1.35 g / cm and SiO: Na _p 0 = 3.3 °) at 11 l / h and conc. H ₂ SO ^ (96 # ig) dosed with ο, 965 l / h. During this reaction phase, the contents of the container are pumped through the disperser 3 times. The silica suspension is then adjusted to a pH of 3 »5 with 96 # strength sulfuric acid, which is achieved by an acid inflow of 1.25 l / h for 35 minutes.

Dispersion also takes place during this reaction phase. Yield; 8 kg of silica. The washed filter cake is dried and ground with a pin mill

8 kg of silica. The washed filter cake is at 11o-T2o C

The precipitated silica is a finely dispersed white powder which is characterized by the following data:

Gltihloss (iooo ° C) to., 5 wt. #

S0 ^ ~ ² content: o _f o8 "

pH value (k% ± ge suspension): 6.2o

Debris weight: 78 g / l

DBP number (structure): 2.84 ml / g

Particle size distribution (Bahcoanalyse) s 6o, 3% wt. ^ 2.1 μ

93.7 wt.% <3.4 μ

98.4 wt.% <6.9 μ

99.9 wt. # <24.9 µ

The silicas produced as described above are characterized by high values of DBP absorption (high structure). And resemble the spray-dried silicas. They also have a high degree of fineness, which that of the spray-dried Silicas far outperforms and the well-known high degree of fineness of steam-jet or air-jet milled xerogels does not come close. As a result, the dispersed silicic acids exhibit E.g. an enormously high ability to float in water, which none of the other named silicas can match. The following The table shows the previous statements:

T09817 / 1708

" ⁵ - copy

Characteristic: Commercially available
Xerogel, ver
grind Hand e 1 siibl i ches
Xerogel, steam
steel wedded Spray beverage KS
donated
len invented
manure
mfiss ver
turned
pebble
acid
(Pen-
grinder DDP number *
ml / g 1.77 2.28 2.83 2.85 Petroleum-
recording
Weight i » 18o 2k 5 26o 271 Massenan
share under
2μ **
Weight % 7th 41 1.8 57 Floating
ability
in water h3 82 . 57.5 9 R, k HET-Oberf1.
«Π / g 23o 23o I80 246 PH value 6.5 6.5 6.6 6.2 Bulk
weight g / l 1 oo 47 87 · 78 Glow loss
(1ooo ° C) 11 π 8.2 1o, 5

* ■ Determination according to the Cabot method with the Hrabender-PLasto ^ raphon ** Determination by Dahco comanalysis. ·

10 98 1 7/170

COPY

- -. - 6 -. ;. ■■; .- '■■■ - ■■ _-

The combination of a high DBP number (high structure) with extreme Fine division determines the excellent suitability of the dispersed Silicas with regard to their use according to the invention as Carrier filler ^ for liquid, pasty and waxy active ingredients of all kinds, / especially in pesticide formulations and cattle feed additives.

The invention is illustrated by the following examples: Example 1; .

The silica described above is used as a carrier filler used and compared in their effect with that of other silicas - namely with that of a milled commercially available, with a commercially available and with that of a milled spray-dried silica.

After a test analogous to petroleum intake *, malathion intake is determined ** determined in $. Malathion is listed as a 9 "$ 5 i.ges technical Product applied to pesticide formulations. The following Values are determined for the malathion intake; Commercial silica, ground: $ 21o

Commercial silica, steam jet milled: $ 23o Spray dried silica, grind: $ 318

Dispersed Silica of the Invention, $ 316

marry:

* Petroleum absorption

In a 250 ml beaker, 5 g filler are rubbed with a glass rod with petroleum, which is added dropwise from a burette. The end point of oil absorption is reached when the filler-petroleum mixture lifts off the glass wall in the form of flakes when rubbed vigorously and can be kneaded together as a waxy mass. The amount of petroleum absorbed is given in percent by weight (petroleum for chromatography; d β o, 79 _t from Merck).

-.7 10 9817/170 8

* * Malathion intake

The determination is carried out in the same way as the kerosene uptake, whereby it should be noted that the end point is reached when the filler on the wall of the beaker becomes waxy. It is important to ensure that special precautionary measures are to be taken when working with malathion, as it is an extremely toxic substance.
(Used is "a $ 95 iS ^it malathion Merck; D = 1.22).

In the malathion intake, the dispersed or the spray-dried Put silica aside. Both silicas outperform the normal and also the steam-jet milled silicas noticeable in their ability to absorb malathion. It consequently follows that the dispersed silicas according to the invention to powdery dust concentrates can be processed, the active ingredient concentration of which can be increased to over 70% by weight.

Similarly highly concentrated dust concentrates can also be used for other major liquid pesticides like parathion and chlordane produce.

In the case of malathion spray powder, due to the high absorption capacity of the carrier silica, the recipe by lowering the silica content and increasing the amount of cheap cheaper mineral filler kaolin.

Example 2;

This example shows the extraordinarily high absorption capacity of dispersed silica and their invented

/ Additive application as intended as a carrier filler for cattle feed shown.

The active ingredient to be absorbed is a '7o $ ig ^e aqueous solution of choline chloride.

10981? / Ϊ? 08 ⁸

In a common household mixer, 30 g of a ground, Disperse silica with ^ 3 »^ ml of previous choline chloride solution mixed. The amount of choline chloride absorbed is 55% by weight. The mixture of carrier silica and active ingredient creates a loose free flowing powder.

A spray-dried, ground silica produces a lumpy one in this test. sticky chunks of existing mass.

109817/170

Claims (3)

P at ft.tt fan s ρ r ü c Ii e 1.) Use of a finely divided, wet-precipitated silica with boiler, determined by the dibutyl phthalate 'AbsQrptionszafol of 2.2 t> is 3 ml / g, structure and a large grain size of
less than 7 hours with one determined according to Bahco-Ioalysis
Grain distribution of ste & cÄabs 57 wt.% Massera proportions of ^ 2 μ grain size as a carrier filler for liquid _s pasty
or waxy active ingredients of various types or their
high percentage solutions,. 2.) Use of a silica according to claim 1 as a carrier filler for liquid, paste-like or waetts-like cattle feed ingredients or their 100% solutions
to a loose, free-flowing powder-like powder concentrate with a high concentration of active ingredients. 3.) Use of a silica according to Claim 1 as carrier filler for liquid, paste or wax-like pesticide active ingredients or their high proof LcSstiageti, if applicable aa with other components, such as mineral fillers, dispersants and wetting agents to form a high strength wettable powder formulation or to a high-process egg powder concentrate. Goth
2o.1o.67 10981371708