Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N35/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical
  • A01N35/02—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical containing aliphatically bound aldehyde or keto groups, or thio analogues thereof; Derivatives thereof, e.g. acetals
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/113—Silicon oxides; Hydrates thereof
  • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
  • C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/28—Compounds of silicon
  • C09C1/30—Silicic acid
  • C09C1/3081—Treatment with organo-silicon compounds
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability

Definitions

• the invention relates to a silica dispersion, a process for production thereof and also use thereof.
• Pulverulent hydrophobic silica is used for controlling sucking insects, wherein the application proceeds by means of dusting (DE 3 835 592) .
• aqueous dispersions which are likewise described in DE 3835592, which consist of a hydrophobic silica and water, do not exhibit sufficient stability.
• US 5830512 describes a dispersion in which sufficient stability is achieved by adding hydrophilic substances, such as, for example, silicas. However, by this means the active hydrophobic component is diluted by a hydrophilic substance. In addition, only a very low stability of the dispersion from hours to a few days is achieved.
• hydrophilic substances such as, for example, silicas.
• EP 1 250 048 discloses stabilizing the dispersion of hydrophobic silica by gelling additives, such as xanthan gum, sodium alginates or neutralized carboxy- vinyl polymers, wherein mixtures of these additives are also possible.
• gelling additives such as xanthan gum, sodium alginates or neutralized carboxy- vinyl polymers
• DE 10 2004 021 532 discloses a dispersion which, in addition to water, contains 0.5 to 20% by weight hydrophobic silica, 0.01 to 10% by weight of a gelling additive, or viscosity-increasing additive, 0.1 to 1% by weight of a preservative, 0 to 1% by weight of a surface-active substance.
• This dispersion can be used as insecticide against 200700371
• the known dispersion has the disadvantage that it loses activity at high atmospheric humidity, because the mites cannot then be dried out to the required extent. This fact is shown graphically in Figure 1.
• the object was therefore to modify the silica dispersion such that activity of the dispersion is provided even at high atmospheric humidity.
• the invention relates to a dispersion containing, in addition to water, 0.5 to 20% by weight of hydrophobic silica, 0.01 to 10% by weight of a gelling additive, or viscosity-increasing additive, which dispersion is characterized in that, as further components, it contains at least one phenol or at least one phenol derivative and/or at least one aldehyde.
• the dispersion as phenol derivative, can contain p-chloro-m-cresol .
• the dispersion as aldehyde, can contain glutardialdehyde .
• the content of p-chloro-m-cresol in the dispersion can be 0.1 to 5% by weight, preferably 0.1 to 0.5% by weight .
• the content of glutardialdehyde in the dispersion can be 0.1 to 5% by weight, preferably 0.5 to 3% by weight.
• the fraction of water can be 68 to 99.4% by weight.
• the specific density of the dispersion can be greater than 0.6 g/ml, preferably 0.7 to 1.02 g/ml .
• hydrophobic silica use can be made of a 200700371
• hydrophobized silica can have a BET surface area of 20 to 600 m 2 /g.
• hydrophobic silica use can be made of a pyrogenically produced silica which has been hydrophobized using hexamethyldisilazane (HMDS) . It can have a BET surface area of 220 ⁇ 25 m 2 /g and a carbon content of 3.0 to 4.0% by weight.
• HMDS hexamethyldisilazane
• the gelling additive or viscosity-increasing additive can be a biopolymer, such as, for example, xanthan gum, sodium alginate, carob bean meal, pectin, agar, carrageenans, alginates and/or neutralized carboxyvinyl polymers, or mixtures of these substances.
• the dispersion according to the invention can contain, in addition, preservatives.
• preservatives use can be made of preservatives which are approved for foods. These can be: sorbic acid, sodium sorbate, potassium sorbate, calcium sorbate, benzoic acid, sodium benzoate, potassium benzoate, calcium benzoate, PHB ethyl ester, PHB ethyl ester sodium salt, PHB propyl ester, PHB propyl ester sodium salt, PHB methyl ester, PHB methyl ester sodium salt, sulphur dioxide, sodium sulphite, sodium hydrogensulphite, sodium disulphite, potassium disulphite, calcium disulphite, calcium hydrogen- sulphite, biphenyl, orthophenylphenol, sodium ortho- phenylphenolate, thiabendazole, nisin, natamycin, formic acid, sodium formate, calcium formate, hexamethylenetetramine, dimethyl dicarbonate, propionic acid, sodium propionate, calcium propionate, potassium propionate .
• the preservatives can be present in an amount of up to 0.1% by weight .
• the dispersion according to the invention can additionally contain surface-active substances in an amount of up to 1% by weight.
• ionic, nonionic and anionic surfactants use can be made of ionic, nonionic and anionic surfactants.
• the invention further relates to a process for producing the dispersion according to the invention which is characterized in that the individual components are dispersed successively or together in water, in which case the individual components are deaerated before and/or during the addition, or the dispersion is deaerated during the individual dispersion steps and residual dispersed air which is still present is finally removed by further mixing under vacuum.
• the deaeration can be carried out by means of application of vacuum.
• a stable and active dispersion can be achieved which does not contain extensive amounts of air.
• This deaerated dispersion can be achieved by the dispersion of previously deaerated hydrophobic Si ⁇ 2.
• subsequent deaeration of the dispersions is technically possible, it can only be achieved with great effort owing to the increased viscosity of the homogeneous phase water (gelling agent as additive) .
• At least a part as large as possible of the air which can be dispersed can be removed by deaeration measures before or during the dispersion. 200700371
• any dispersion process is suitable that either makes possible prior deaeration of the powder to be dispersed or prevents air being dispersed during the dispersion.
• One embodiment of the deaeration and dispersion is the utilization of a vacuum dissolver.
• water and the gelling additive can be briefly predispersed, then the entire amount of hydrophobic SiC>2 added without stirring to the surface of the solution, the mixture evacuated and only then dispersion of the hydrophobic SiC>2 started.
• a PSI Mix ® from NETZSCH can also achieve this deaeration of the powder.
• deaeration units such as the DA-VS NETZSCH vacuum deaerator from NETZSCH, a vacuum-thin-film rotary process.
• the invention relates to the synergistic action of the known dispersion with further biocidal additives for extending the activity spectrum into the "disinfecting range" also.
• the activity of the dispersion is restricted essentially to adult mites owing to the more physical mechanism of activity ("defatting/dewaxing" of the mite surface followed by a fatal course of water loss due to drying out) .
• the mite eggs in particular do not appear to be damaged by this "non-chemical attack”.
• DISPERMAT ® laboratory dissolver from VMA-GETZMANN GMBH having the CDS vacuum system.
• the CDS dispersion system permits dispersion processes to be carried out in vessels in a completely closed system under vacuum.
• a toothed disk of 70 mm diameter was used.
• the silica used is the pyrogenically produced, hexamethyldisilazane-hydrophobized (HMDS) silica AEROSIL ® 812S.
• This silica is based on the pyrogenically produced silica AEROSIL ® 300. It has a BET surface area of 220 ⁇ 25 m 2 /g and a carbon content of 3.0 to 4.0% by weight.
• Aerosil R 812 S are charged and the mixture is deaerated for 10 min under vacuum without stirring.
• Aerosil R 812 S is dispersed at 2000 rpm under vacuum.
• 0.5 g of p-chloro-m-cresol is stirred into 476.5 g of deionized water (cresol melts at approximately 60 0 C) at 500 rpm. Thereafter, 1 g of lecithin and 7.5 g of Satiaxane xanthan gum are added and the mixture is dispersed for 15 min at 1000 rpm under vacuum on the dissolver. Then, 15 g of Aerosil R 812 S are charged and the mixture is deaerated for
• Aerosil R 812 S is dispersed at 2000 rpm under vacuum.
• Dispersions R 10, R 14 and R 13 were produced in a similar manner to R 5.
• mite eggs For determination of the activity (mortality) on mite eggs, in each case approximately 100 mite eggs are placed onto a freshly spread active compound coating (wet film thickness 200 ⁇ m) on a galvanized steel plate in a plastic Petri dish, stored in a climatically controlled chamber and after, for example 24 h, the mite eggs are evaluated or the hatched larvae are enumerated. 200700371
• a combination of R 2 and R4 with 2% glutardialdehyde + 0.35% p-chloro-m-cresol is particularly advantageous .
• the hydrophobic, pyrogenically produced S1O 2 of the dispersion according to the invention is responsible for killing the mites
• the dispersion R 13 according to the invention - in contrast to a known disinfectant concentrate - is an emulsion and is also applied in undiluted form in the animal house, the DVG method was modified in such a manner that an opinion and a listing is possible.
• the dilutions of the disinfectant were made up with sterilized water of standardized hardness (WSH) immediately before the test.
• WSH sterilized water of standardized hardness
• the dispersion R 13 according to the invention is only miscible with WSH up to a ratio of 20% w/v, so that higher concentrations were not tested.
• step dilutions of the dispersion R 13 according to the invention with concentrated casein peptone-soybean meal peptone solution were produced, inoculated with a defined number of test microorganisms and subsequently incubated.
• quantification of the test organisms used was carried out in the surface process (before and after testing) , in order to be able to determine the bacteriostatic disinfectant concentration.
• a phenol dilution series was run in conjunction for control and for comparison.
• the minimal inhibitory concentration (MIC) determined of the dispersion R 13 according to the invention is between 7.5% (for Salmonella enterica ssp. enterica and Proteus mirabilis) and 15% (for Enterococcus faecium) . 200700371
• the bactericidal action of the dispersion R 13 according to the invention was determined in accordance with the DVG Guidelines IV. A.3 in the suspension test without and with protein loading.
• microorganism suspension was added to the disinfectant dilution to be tested and after defined exposure times in each case a sample was taken and superinoculated.
• the test proceeded not only without protein loading but also with a protein loading of 20% bovine serum.
• the dispersion R 13 according to the invention acted in the course of 30 minutes on all bacterial test microorganisms in a concentration of 4% and therefore below the established MIC.
• Salmonella enterica not only in the test without protein loading but also with protein loading was killed by a concentration of 6% in the course of 15 minutes, or a concentration of 10% in the course of 5 minutes. Since the product is used undiluted in the animal house, a still stronger activity can be assumed in practical use. 200700371
• the bactericidal action of the dispersion R 13 according to the invention in the germ carrier test was determined according to the method specified in the DVG guidelines under IV. A.4. In this case, not only product dilutions (10% and 20%) but also undiluted product was tested. It was found that the dispersion R 13 according to the invention, owing to its rheological properties, cannot penetrate into the germ carrier linden wood in sufficient active compound concentration so that here no activity sufficient according to the method was detectable.
• the dispersion R 13 according to the invention is readily active in the suspension test with and without protein loading, and only in the case of short-time exposure has a marked protein defect.
• the limiting factor is the determination of the MIC in the bacteriostasis test.
• the use of the dispersion R 13 according to the invention is possible for preventive disinfection in the animal husbandry sector. It must be noted that the product (contrary to the present test) is employed undiluted in the animal house and therefore the action on site may be still higher than can be declared according to the method.
• the dispersion R 13 according to the invention is unsuitable for special disinfection, since the penetration capacity into linden wood which is required for this cannot be ensured.

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Environmental Sciences (AREA)
• Wood Science & Technology (AREA)
• Plant Pathology (AREA)
• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Dentistry (AREA)
• General Health & Medical Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Zoology (AREA)
• Inorganic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Pest Control & Pesticides (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Silicon Compounds (AREA)

Priority Applications (6)

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• 2007
  • 2007-09-06 DE DE102007042417A patent/DE102007042417A1/de not_active Withdrawn
• 2008
  • 2008-08-14 PL PL08787226T patent/PL2188214T3/pl unknown
  • 2008-08-14 WO PCT/EP2008/060692 patent/WO2009030588A1/en not_active Ceased
  • 2008-08-14 US US12/676,373 patent/US20100203173A1/en not_active Abandoned
  • 2008-08-14 EP EP08787226A patent/EP2188214B1/en active Active
  • 2008-08-14 ES ES08787226T patent/ES2394891T3/es active Active
  • 2008-08-14 CN CN2008801052881A patent/CN101795966B/zh active Active
  • 2008-08-14 JP JP2010523466A patent/JP5328791B2/ja active Active

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