Dispersion of hydrophobisated silicon dioxide particles and granules made therefrom

FIELD: chemistry.

SUBSTANCE: disclosed is a method of producing a dispersion of silicon dioxide particles with a modified surface, having mean diameter of not more than 100 nm, via high-pressure grinding of a pre-dispersion containing a) 10-50 wt % silicon dioxide particles with a modified surface, b) at least one glycol monoether of general formula H3C(CH2)m-O-(CH2)n-[O-(CH2)o]p-OH (A), c) at least one carboxylic ester of general formula H2x+1Cx-O-CH2-(CHR)-[O-CHR]y-O-C(=O)-CzH2z+1 (B), where the molar ratio A/B ranges from 10:90 to 40:60 and m, n, o, p, x, y and z do not depend on each other. Also disclosed is a dispersion obtained using the disclosed method, a method of producing granules of silicon dioxide particles with a modified surface by separating the liquid phase of the dispersion, granules obtained using the disclosed method and use of the dispersion and granules in coating materials.

EFFECT: disclosed dispersion and particles can be used in transparent coating compositions.

10 cl, 2 tbl, 6 ex

 

The present invention relates to a method for producing a dispersion of particles of the silicon dioxide surface modified with an organic solvent, and the dispersion obtained in this way. The present invention also relates to a method for producing granules based on the variance and to these granules.

Long known particles of silicon dioxide as a component of coating compositions. The present invention is to develop coating compositions, which are characterized by a particularly high degree of transparency and resistance to scratching, combined with good technical characteristics and storage stability.

In EPA 943664 disclosed containing nanoparticles transparent film-forming binder, which is obtained by ink jet dispersing the nanoparticles in the binder. Examples of nanoparticles that can be used include hydrophobizated obtained by pyrogenic method particles of silicon dioxide.

In contrast, EPA 1923412 found that the method disclosed in EPA 943664, does not provide effective dispersion used hydrophobized obtained by pyrogenic method, particles of silicon dioxide and therefore there are cases of opacity of the film-forming binder.

In EPA 1923412 additionally it was found that obtained by the pyrogen is th methodology particles of silicon dioxide have a modular structure and therefore they are unsuitable for use as a component of coating compositions to obtain highly transparent coatings,

In DEA 102006020987 also noted that cases of turbidity of the compositions of the coatings probable when using obtained by pyrogenic method of silicon dioxide. Therefore, DEA 102006020987 proposed to use special stucture-modified pyrogenic (colloidal) silica. Particles of silicon dioxide can stucture to modify, for example, by mechanical impact and possible subsequent grinding. Thus it is possible to reduce the number of cases of opacity of the coating compositions.

Obtained by pyrogenic method particles of silicon dioxide are easily accessible and of high purity. In their dispersions are usually aggregated patterns part lead to lack of transparency. Although increasing transparency can be used grinding ball mill, the material is separated from the balls, pollutes the variance. Also, when the dispersion with a high energy organic dispersant additives can decompose and this can lead to cases of turbidity, reduced stability and high viscosity.

Therefore, an object of the present invention is to obtain aggregated particles of silicon dioxide, in particular obtained by pyrogenic method in a form that enables them to be used in the clear coating compositions.

This izobreteny which relates to a method for producing a dispersion of particles of silicon dioxide with a modified surface, having an average diameter of not more than 100 nm using carried out at high pressure grinding preliminary dispersion containing

a) from 10 to 50 wt.% particles of silicon dioxide with a modified surface, which

at least partially aggregated and

- associated with the component, modifying the surface of SiOSi linkages and

- still contain reactive groups on their surface,

b) at least one simple monoether glycol of General formula

in which

m=0, 1, 2 or 3,

n and o=2, 3, or 4, and

p=0 or 1,

c) at least one ether carboxylic acids of General formula

in which

R=H, CH3With2H5or3H7,

x and z=1, 2, or 3, and

y=0 or 1,

d) the molar ratio a/b is from 10:90 to 40:60 and m, n, o, p, x, y and z do not depend on each other.

Reactive groups on the particle surface are such that are already on the surface of the particles used, as well as groups that were formed during the dispersion operation.

Reactive groups are predominantly or exclusively of group IT. These reactive groups may be completely or only partially interact with components of the liquid phase with the formation of the Cove is Lenten, ionic or coordination bonds. The reason for this is partly that, for example, a single reactive group not available due to steric shielding connections, modifying the surface.

In the method proposed in the present invention, at least part of the used particles of silicon dioxide with a modified surface is in the form of aggregates. Part means that the share of the aggregated particles is not less than 5 wt.% in terms of the sum of the number of aggregated and non-aggregated particles; in the context of the present invention are primary particles. However, it is preferable to use particles that are in a very aggregated form, i.e. in a degree constituting not less than 80 wt.%, usually in a degree constituting not less than 90 wt.% in terms of the sum of the number of aggregated and non-aggregated particles. The content can be determined, for example, by counting the images obtained by TEM (TEM=transmission electron microscopy).

The units are solid primary particles are connected, for example, tails sintering. In turn, the units can be combined with the formation of agglomerates in which the units are only weakly related to each other. The agglomerates can be re-destroy simply by the application slightly the th shear energy.

The average diameter of the particles contained in the dispersion after grinding at high pressure, including agglomerates and primary particles is not more than 100 nm. Preferably from 50 to 100 nm, more preferably from 60 to 90 nm.

The average diameter of the particles contained in the preliminary dispersion exceeds 100 nm. The average particle diameter may be from 200 nm to several hundreds of micrometers and these include primary particles, aggregates and agglomerates. Typically, the diameter of the particles is from 10 to 500 μm. It can be defined, for example, using dynamic light scattering. Pre-dispersion can be prepared at much lower shear rates than the variance. For example, you can use conventional mixers, the apparatus for dissolving or rotor/stator machine. Preliminary dispersion mainly intended for destruction of agglomerates of particles of silicon dioxide with a modified surface, which may be formed by combining the aggregates due to cohesive forces.

Depending on the specific use surface modifier and the specific quantity it is possible to obtain particles dioxide Varenna, with different degree of hydrophobicity or hydrophilicity. One measure of surface characteristics used in the way that particles of silicon dioxide is surface modified, from hydrophilicity to hydrophobicity, is wetting with methanol. When determining the wettability of methanol in each case 0.2 g (±0.005 g) of hydrophobic particles of silicon dioxide weighed in transparent tubes for centrifuges. Each weighted sample added to 8.0 ml of a mixture methanol/water, in each case containing 10, 20, 30, 40, 50, 60, 70 and 80% vol. of methanol. The covered tubes shaken for 30 s and then centrifuged at 2500 min-1within 5 minutes, Determine the volume of the sludge are converted to percentages and build its dependence on the content of methanol (vol.%). Extreme point of dependence corresponds to the methanol wettability. The greater the wettability of the methanol, the greater the hydrophobicity of the particles of silicon dioxide. The methanol wettability used particles of silicon dioxide with a modified surface is preferably from 20 to 50, more preferably from 25 to 45, and most preferably from 30 to 40.

Usually not all of the reactive groups used particles of the silicon dioxide surface modified interact with the surface modifier. In particular, the role of the accessibility of the reactive groups.

In one preferred embodiment, the method proposed in the present invention, it is possible to use particles dioxide cream the Oia with a modified surface, which is obtained by surface modification of the particles of pyrogenic silicon dioxide, i.e., obtained by hydrolysis in a flame or by oxidation in the flame. You can also use subjected to further surface modification products. The structure of the particles of the silicon dioxide surface modified can be modified by mechanical impact and possible subsequent grinding. The structure can be modified, for example, using a ball mill or a ball mill continuous action. Subsequent grinding can be carried out, for example, using vostokstrojj mills, toothed disc mill or a pin mill. Modification of the structure is also described in EPA 808880 and DEA 102006048509.

Modifiers to obtain particles of the silicon dioxide surface modified contained in the preliminary dispersion, are those which contain at least one functional group that can form SiOSi bond with the reactive groups on the surface modified particles of silicon dioxide.

In addition to the functional groups that can form a chemical bond with the surface group of particles, the modifier usually contains a molecular radical, which after the accession of the surface modifier can make the particle more or less hydrophob is s or hydrophilic characteristics.

The surface modifiers, preferably used to obtain the used particles of the silicon dioxide surface modified, are silanes. In the carbon chains of these compounds can be included in the group O, S or NH. You can use one or more modifiers. Used silanes containing at least one dehydrolinalool group.

Preferred silanes are described General formula RxSiY4-x(I)in which x is 1, 2 or 3, and the radicals R are identical or different and are all neytralizuya groups, and the radicals Y are the same or different and are all gidrolizuemye groups or hydroxy groups.

In the General formula (I) gidrolizuacy groups Y, which may be identical or different, represent, for example,

- hydrogen

halogen, such as F, Cl, Br or I,

- alkoxygroup, preferably C1-C6-alkoxygroup, such as a methoxy group, ethoxypropan, n-propoxylate, isopropoxy and butoxypropyl,

- alloctype, preferably6-C10-alloctype, such as fenoxaprop,

- alloctype, preferably C1-C6-alloctype, such as acetoxy or propionyloxy,

- alkylsulphonyl, preferably2-C7 -alkylsulphonyl, such as acetyl.

Preferred gidrolizuacy radicals are halogen, alkoxygroup and alloctype. Especially preferred gidrolizuacy radicals are1-C4-alkoxygroup, preferably the methoxy group and ethoxypropan.

Neytralizuya radicals R, which may be the same or different, are radicals R with a functional group or without it.

Neytralizuya radical R without a functional group is,for example,

- alkyl, preferably C1C8-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl, pentyl, hexyl, octyl or cyclohexyl; substituted alkyl,

alkenyl, preferably2-C6alkenyl, such as vinyl, 1-propenyl, 2-propenyl and butenyl,

- quinil, preferably2-C6-quinil, such as acetylenyl and propargyl,

- aryl, preferably6-C10-aryl, such as phenyl and naphthyl, and the corresponding alkylaryl and arylalkyl, such as tolyl, benzyl and phenethyl.

Preferred surface modifiers may constitute, in particular,

Neytralizuya radical R with a functional group may, for example, contain as functional groups epoxy the foam (such as glycidyl or glycidyloxy), the hydroxy-group, ether group, amino group, monoalkylamines, dialkylamines, optionally substituted aniline group, amide group, carboxypropyl, acryloyl, acryloyloxy, methacryloyl, methacryloyloxy, mercaptopropyl, cyano, alkoxygroup, isocyanate group, aldehyde group, alkylaryl, the anhydride group of the acid group and phosphoric acid.

Preferred examples neytralizuya radicals R having functional groups are

- glycidyl or glycidyloxy-(C1-C20)-alkalinity radical, such as beta-glycidyloxy, gamma glycidyloxy, Delta glycidyloxy, Epsilon-glycidyloxy, omega-glycidyloxy and 2-(3, 4-epoxycyclohexyl)ethyl,

- (meth)acryloyloxy-(C1-C6)-alkalinity radical, such as (meth)acryloyloxy, (meth)acryloyloxy, (meth)acryloyloxy or (meth)acryloyloxy, and

- 3-isocyanatopropyl radical.

Specific surface modifiers that can be used are gamma glycidylmethacrylate, glycidylmethacrylate, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminomethyltransferase, aminomethyltransferase, AMI is propyltrichlorosilane, (N-cyclohexylamine)triethoxysilane,

2-amino-ethyl-3-aminopropyltrimethoxysilane,

N-(n-butyl)-3-aminopropyltrimethoxysilane,

2-amino-ethyl-3-aminopropyltrimethoxysilane,

(3-aminopropyl)diethoxymethylsilane,

(3-aminopropyl)ethyldichlorosilane,

(3-methylaminopropyl)trimethoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane,

(N,N-diethyl-3-aminopropyltrimethoxysilane,

(N,N-dimethylamino)dimethylchlorosilane,

(N,N-dimethylaminopropyl)trimethoxysilane,

(N-acetylphenyl)-3-aminopropyltrimethoxysilane,

(N-cyclohexylamine)metildigoxin,

(N-cyclohexylamine)triethoxysilane,

(N-phenyliminomethyl)metaldimension,

(N-phenyliminomethyl)trimethoxysilane,

11-aminoheterocycles,

3-(1,3-dimethylbutylamino)aminopropyltriethoxysilane,

3-(1-aminopropoxy)-3,3-dimethyl-1-propyltrimethoxysilane,

3-(2,4-dinitroaniline)propyltriethoxysilane,

3-(2-aminoethylamino)propylmethyldimethoxysilane,

3-(2-aminoethylamino)propyltrimethoxysilane,

3-(cyclohexylamino)propyltrimethoxysilane,

3-(aminophenoxy)propyltrimethoxysilane,

3-(N-allylamino)propyltrimethoxysilane,

3-(N-sterility-2-aminoethylamino)propyltrimethoxysilane,

3-(phenylamino)propyltrimethoxysilane,

3-aminopropyltrimethoxysilane,

3-aminopropyldimethylamine cicilan,

3-aminopropylsilyl(trimethylsiloxy)silane,

3-aminopropyltriethoxysilane,

3-aminopropyl(methoxyethoxyethoxy)silane,

3-aminopropyl(trimethylsiloxy)silane,

4-aminoethylthiomethyl, aminodinitrotoluenes, bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane,

diethylaminoethylmethacrylate,

N,N-dimethylaminoethylmethacrylate,

N-(2-amino-ethyl)-3-aminoisobutyrate,

N-(2-amino-ethyl)-3-aminopropyltrimethoxysilane,

N-(2-amino-ethyl)-3-aminopropyltriethoxysilane,

N-(2-amino-ethyl)-3-aminopropyltrimethoxysilane,

N-(2-aminomethyl)-11-aminoheterocycles,

N-(3-acryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane,

N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane,

N-(6-aminohexyl)aminopropyltrimethoxysilane,

N-(hydroxyethyl)-N-methylenedicyclohexyl,

N-3-[(amino(polipropilene)]aminopropyltrimethoxysilane,

n-buylamisilnoprescriptionsale,

N-cyclohexyltrichlorosilane,

N-ethylenediaminetriacetate,

N-ethylenediaminetetramethylene,

N-methylenedioxymethylamphetamine,

N-methylenedicyclohexyl,

N-phenylaminopyrimidine, phenylbis(dimethylamino)chlorosilane,

tert-buylamisilnoprescriptionsale, aminopropyl what elantris,

N-(2-amino-ethyl)-3-aminopropylsilyl,

N-cyclohexylbenzothiazole,

N-cyclohexyldiazeniumdioxy and

N-phenylaminopyrimidine,

3-(meth)acryloyloxyhexyloxy and

3-(meth)acryloyloxyhexyloxy.

In addition, the surface of the particles of the silicon dioxide contained in the preliminary dispersion, it is also possible to modify silylamine. Silylamine mean compounds which contain at least one link with SiN and which can interact with the SiOH groups on the surface of particles of silicon dioxide. Their examples are vinylimidazole, octylimidazolium, phenyldimethylsilane, bis(dimethylaminomethylene)ethane, hexamethyldisilazane, (N,N-dimethylamino)trimethylsilane and bis(cryptochromes)tetramethyldisilazane. You can also use a circular silazane.

Suitable surface modifiers are also cyclic polysiloxane D3, D4, D5, and their homologues, D3, D4 and D5 mean cyclic polysiloxane containing 3, 4 or 5 units of the type SiO(CH3)2for example octamethylcyclotetrasiloxane=D4. Additional polysiloxane or silicone oil type YO[(RR'SiO)m(R"R'"SiO)n]uY, where

m=0, 1, 2, 3,... ∞, preferably 0, 1, 2, 3,... 100000,

n=0, 1, 2, 3,... ∞, preferably 0, 1, 2, 3,... 100000,

=0, 1, 2, 3,... ∞, preferably 0, 1, 2, 3,... 100000,

Y=CH3, H, CnH2n+1n=2-20; Si(CH3)3Si(CH3)2H, Si(CH3)2HE, Si(CH3)2(Och3), SiO(CH3)2(CnH2n+1), n=2-20, R, R', R", R'" are all independently represent alkyl, such asnH2n+1n=1-20; aryl, such as phenyl radicals and substituted phenyl radicals, (CH2)n-NH2, H. Polysiloxane or silicone oil to the surface modification is usually thermally activated.

Suitable particles of silicon dioxide with a modified surface that can be used in the preliminary dispersion, are commercially available materials AEROSIL®R104, AEROSIL®R106, AEROSIL®R202, AEROSIL®R805, AEROSIL®R812, AEROSIL®R812 S, AEROSIL®R972, AEROSIL®R974, AEROSIL®R8200, AEROXIDE®LE-1 and AEROXIDE®LE-2, AEROSIL®R9200, AEROSIL®R8200 and AEROSIL®R7200, all produced by the company Evonik Degussa.

The carbon content used in the particles of silicon dioxide with a modified surface may preferably be from 0.1 to 2.5 wt.%.

Particularly preferably, you can use AEROSIL®R974, which is obtained by the reaction of AEROSIL®200 clear.

The content of the used particles of silicon dioxide with a modified surface is Yu in terms of the preliminary dispersion is from 10 to 50 wt.% and depends on factors such as the nature of the surface modification used particles of silicon dioxide and the liquid phase composition. Content from 20 to 40 wt.% is preferred.

An important component in the method proposed in the present invention, is one or more simple monoamino glycols of General formula

in which

m=0, 1, 2 or 3,

n and o=2, 3, or 4, and

p=0 or 1.

Preferred are as follows; m=2 or 3, n=2 or 3, o=2 or 3 and p=0 or 1. Especially preferred are the following possibilities: m=2, n=2, o=2 and p=1. Most preferably it is possible to use H3C(CH2)3O(CH2)2HE.

Another important component in the method proposed in the present invention, is one or more esters of carboxylic acids of General formula

in which

R=H, CH3With2H5With3H7,

x and z=1, 2, or 3, and

y=0 or 1.

Preferred are the following possibilities: x=1, R=H or CH3, y=0 or 1 and z=1 or 2.

Especially preferred is the following possibility: x=1, R=CH3, y=0 and z=1, i.e. H3PINES2(SNSN3)OS(=O)CH3.

In addition, for the method proposed in the present invention, it is important that the molar ratio of N3C(CH2)m -O-(CH2)n-[O-(CH2)about]pHE (A)/H2x+1Cx-O-CH2-(CHR)-[O-CHR]y-O-C(=O)-CzH2z+1(C) ranged from 10:90 to 40:60, preferably from 15:85 to 35:65, more preferably from 20:80 to 30:70.

Compounds of the General formulas a and b usually form the liquid phase of the dispersion is proposed in the present invention. However, the dispersion may also contain additional solvents that can be added after grinding at high pressure. For mixing of the components is sufficient to use a mixer or other apparatus for dissolution. Suitable solvents can be alcohols, ethers, ketones and aromatic compounds.

Suitable alcohols may include methanol, ethanol, n-propanol, isopropanol, n-butanol, Isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, second-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, second-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonlevy alcohol, 2,6-dimethylheptan-4-ol n-decanol, second-undecylenic alcohol, trimethylantimony alcohol, sec-tetradecanoyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, datetoday alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-Boo is jinglian, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropyleneglycol, hexanediol, octanediol, triethylene glycol, tripropyleneglycol and glycerin.

Suitable esters may include the following: diethylcarbamyl, ethylene carbonate resulting, propylene carbonate, methyl acetate, ethyl acetate, gamma-butyrolactone, gamma-valerolactone, n-propyl, isopropylacetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentalateral, second-pentalateral, 3-methoxybutyl, methylphenylacetic, 2-ethylbutylamine, 2-ethylhexylacrylate, benzoylacetate, cyclohexylacetate, methylcyclohexylamine, n-nonlateral, methylacetoacetate, ethylacetoacetate, diacetate, glycol, acetate ethoxydiglycol, ethylpropyl, n-butylphosphonate, isoamylamine, diethyloxalate, dibutylamine, mutilated, ethyllactate, n-butylacetate, n-elillactoth, diethylmalonate, dimethylphthalate and diethylphthalate.

Suitable ethers include the following: DIPROPYLENE ether, diisopropyl ether, dioxane, tetrahydrofuran, tetrahydropyran, dimethyl ether of ethylene glycol, diethyl ether of ethylene glycol, DIPROPYLENE ether of ethylene glycol, dimethyl ether of propylene glycol, diethyl ether of propylene glycol, DIPROPYLENE ether of propylene glycol, dimethyl ether of diethylene glycol, diethyl ether dietology is Olya and DIPROPYLENE ether of diethylene glycol.

Suitable ketones may include acetone, methyl ethyl ketone, methyl-n-propylketone, methyl-n-butylketone, diethylketone, methyl isobutyl ketone, methyl-n-Penticton, ethyl-n-butylketone, methyl-n-hexillion, di-n-butylketone, trimethylene, cyclohexanone, 2-hexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, acetophenone, acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,4-octandiol, 3,5-octandiol, 2,4-nonindian, 3,5-nonindian, 5-methyl-2,4-hexanedione and 2,2,6,6-tetramethyl-3,5-heptanedione.

In addition, it is important that the powdered silicon dioxide surface modified, used in the preliminary dispersion was subjected to a grinding operation at high pressure. Grinding at high pressure, for example, you can conduct so that the preliminary dispersion is placed under a pressure of from 50 to 500 MPa, and the pressure drop through the nozzle, for example, a notch or a slit nozzle, the diameter of the hole or slit width of the nozzle is from 0.05 to 1 mm, preferably from 0.1 to 0.5 mm, and the ratio length/diameter for the hole or the ratio of depth/width of the slit nozzle is from 1 to 10. In some cases, this type of dispersion may require the removal of large particles, for example, by filtration or sedimentation.

Preferred is a variant of the method proposed in this is the next invention, in which the prior variance is shared by at least two substream and the latter is placed under pressure and relieve pressure through the corresponding nozzle aimed in the General situation of a collision.

Jet sub flows typically have a rate equal to not less than 300 m·s-1, more preferably from 400 to 1000 m·s-1and most preferably from 600 to 900 m·s-1. The speed means the speed of the sub flows in the nozzle channel. It is defined as the ratio of the volume flow passing through the nozzle, expressed in m3·with-1to the area of the orifice of the nozzle, expressed in m2. The hole diameter is usually from 0.1 to 1 mm, preferably from 0.2 to 0.4 mm

If the variance is used to obtain a translucent cover, and not to obtain a transparent coating, grinding at high pressure can be replaced by a rotor/stator dispersing. Rotor/stator dispersing preferably should be performed with a shear rate equal to 104with-1or more, more preferably at equal to 2·104up to 4·104with-1.

The present invention also relates to the dispersion obtained by the method proposed in the present invention.

The present invention also relates to a method in which pellets of particles of silicon dioxide with a modified surface is thew obtained by separation of the liquid phase dispersion, proposed in this invention.

This can be accomplished, for example, by distillation, filtration or centrifugation. Removal of the liquid phase must not be full. Thus, particles of silicon dioxide with a modified surface obtained by the method proposed in the present invention may contain an attached solvent. If necessary, you can then hold the stage of drying. In addition, the particles obtained after removal of the liquid phase can be washed with suitable solvents and then to separate, for example, by filtration or centrifugation.

It was found that the methods appropriate for removal of the liquid phase, are spray drying and drying by freezing.

In the preliminary dispersion is preferably possible to use particles of silica surface modified with a surface area BET (on the isotherm of the brunauer-Emett-teller)is from 40 to 200 m2/g, and wetting with methanol equal to from 30 to 40, which is obtained by the reaction obtained by pyrogenic method, particles of silicon dioxide with a clear.

The present invention also relates to granules obtained by the method proposed in the present invention. Despite the greater density utracki these pellets are much easier to disperse different than part of the s of the silicon dioxide surface modified, used to obtain the variance, proposed in this invention.

The present invention also relates to the use variance proposed in the present invention, or granules proposed in the present invention is resistant to scratching translucent or transparent surfaces.

Examples

Determination of the viscosity of dispersions: the viscosity of the resulting dispersion is determined using a rotational viscometer Physica model 300 and measuring cylinder SS 27 at 25°C.

Determination of the amount of particles contained in the dispersion: the size of the particles contained in the dispersion is determined using dynamic light scattering. Use the instrument Zetasizer 3000 HSa (Malvern Instruments, UK), Lead parameter is the average volumetric distribution of d50(V).

Determination of the shear rate: shear rate in the context of the present invention in the form of a peripheral speed divided by the distance between the surfaces.

Circumferential velocity can be calculated by the rotor speed and rotor diameter. The distance between the rotor and stator used in the dispersing device is approximately 1 mm.

Example 1 (corresponding to the present invention):

Preliminary dispersion, which contains 30 wt.% AEROSIL®R974, Evonik Degussa, prepared with the help of the apparatus for dissolving in a mixture of N3C-O-CH2-(SNSN3)-O-C(=O)-CH3 and H3C(CH2)3-O-(CH2)2HE, the molar ratio of N3C(CH2)3-O-(CH2)2-HE/H3C-O-CH2-(SNSN3)-O-C(=O)-CH3=22:78.

Then this pre-dispersion is divided into three sub-threads and is placed under pressure and the pressure in the sub-discharge through the diamond nozzle in the General situation of collision, each substream is directed at an angle of 120° with a speed of 700 m·s-1. Then, the resulting dispersion re-grind under the same conditions.

The average diameter of the particles in the resulting dispersion, determined using dynamic light scattering, is 78 nm.

The dispersion obtained through the rotor/stator dispersion is translucent; dispersion obtained by grinding at high pressure, is transparent.

The dispersion obtained by grinding at high pressure, has a very low viscosity.

Table 1
The dependence of viscosity on shear rate
Viscosity [MPa·s], example No.
Shear rate [s-1]14and 5b
0,122,5592,3789,0411,84
1,26919,2492,6479,8525,65
11,7218,883,7261,0124,42
108,3comprised 17.5464,4342,2818,69
100016,150,7189,0411,84

Another feature of the dispersions proposed in the present invention, is that without flocculation or gelation can include conventional dispersing additives, such as, for example, LAD 1045 or Dispers 652, produced by the firm Tego.

Then the dispersion obtained by grinding at high pressure, is subjected to spray drying (inert gas: nitrogen, atomization, 2 liquid nozzle, inlet temperature: 320°C, outlet temperature: 150-170°C; precipitation of solids: cyclone/filter).

These gr is noly have an average diameter, equal to 30 microns.

Example 2 (comparative):

With the help of the apparatus for dissolving 80 g of AEROSIL® R974 pre-dispersed in 154,3 g H3C-O-CH2CH(CH3)-O-C(=O)CH3and 25.7 g of N3C-O-CH2CH(CH3HE, the molar ratio of N3With-O-(CH2)3-HE/H3C-O-CH2CH(CH3)-O-C(=O)CH3=20:80, and then the preliminary dispersion is dispersed with the help of the apparatus, the rotor/stator. The dispersion enters the gel for 1 h obtaining a stable dispersion impossible.

Example 3 (corresponding to the present invention):

With the help of the apparatus for dissolving 90 g of AEROSIL® R974 pre-dispersed in 180 g of N3C-O-CH2CH(CH3)-O-C(=O)CH3and 30 g of N3C(CH2)3-O-(CH2)2HE, the molar ratio of N3C(CH2)3-O-(CH2)2-HE/H3C-O-CH2CH(CH3)-O-C(=O)CH3=16:84 and then the preliminary dispersion is dispersed with the help of the apparatus, the rotor/stator. Within 2 weeks there is only a slight increase in the viscosity of the dispersion.

Example 4 (corresponding to the present invention):

Using the apparatus of the rotor/stator Conti TDS 42,02 kg N3PINES2CH(CH3)OS(=O)CH3and 11,46 kg N3C(CH2)3O(CH2)2HE, the molar ratio of H3C(CH2)3O(CH2)2OH/H3COCH 2CH(CH3)OC(=O)CH3=23:77, and 22,92 kg of AEROSIL R711 is dispersed at a shear rate equal to 20000-1.

Example 5 (corresponding to the present invention):

Using the apparatus of the rotor/stator Conti TDS 42,35 kg N3PINES2CH(CH3)OS(=O)CH3, 11,55 kg N3C(CH2)3O(CH2)2HE, the molar ratio of N3C(CH2)3O(CH2)2HE/H3PINES2CH(CH3)OS(=O)CH3=23:77 and 30,80 kg of AEROSIL®R972 is dispersed at the shear rate equal to 20000-1.

Example 5b:

Then this dispersion is divided into three sub-threads and is placed under pressure and the pressure in the sub-discharge through the diamond nozzle in the General situation of collision, each substream is directed at an angle of 120° with a speed of 700 m ° C. Then, the resulting dispersion re-grind under the same conditions.

The average diameter of the particles in the resulting dispersion, determined using dynamic light scattering, equal to 82 nm.

Example 6: production of a material for coating

Get material for coating with the composition given in table 2. By spraying it put on the painted black paint sheet metal DT and dried at room temperature for 24 h and then at 70°C for 2 hours, the coating Material has a low turbidity with good resistance to scratching,

Table 2
Material to cover (amount in wt. parts [g])
The dispersion of example 133
Macrynal SM 565, 70%122
Methoxypropylacetate0,5
Butyl acetate3
Solvesso 1004
Xyleneof 5.4

1. A method of obtaining a dispersion of particles of the silicon dioxide surface modified, having an average diameter of not more than 100 nm, using carried out at high pressure grinding preliminary dispersion, including
a) from 10 to 50 wt.% particles of silicon dioxide with a modified surface, which
at least partially aggregated and
- associated with the component, modifying the surface bonds Si-O-Si and still contain reactive groups on their surface,
b) at least one simple monoether glycol of General formula

in which m=0, 1, 2 or 3,
n and o=2, 3, or 4, and
p=0 or 1,
c) at least one ether carboxylic acids of General formula is In

in which R=H, CH3With2H5or3H7,
x and z=1, 2, or 3, and
y=0 or 1,
d) the molar ratio a/b is from 10:90 to 40:60 and m, n, o, p, x, y, and z do not depend on each other.

2. The method according to claim 1, characterized in that the used particles of the silicon dioxide surface modified pyrogenic origin.

3. The method according to claim 1 or 2, characterized in that the use of H3C(CH2)3-O-(CH2)2HE.

4. The method according to claim 1 or 2, characterized in that the use of H3C-O-CH2-SSN3-O-C(=O)-CH3.

5. The method according to claim 1 or 2, characterized in that the grinding at high pressure is carried out by dividing the preliminary dispersion is at least two substream, which is placed under pressure and relieve pressure through the corresponding nozzle aimed in the General situation of a collision.

6. The dispersion obtained by the method according to any one of claims 1 to 5.

7. A method of producing granules particles of silicon dioxide with a modified surface, in which the liquid phase dispersion according to claim 6 separate.

8. The method according to claim 7, characterized in that use particles of silica surface modified with a surface area BET, equal to from 40 to 200 m2/g and a methanol wettability comprising from 30 to 40, which is obtained by reaccommodating on pyrogenic method, particles of silicon dioxide with a clear.

9. Granules are particles of silicon dioxide with a modified surface obtained by the method according to any of claims 7 and 8.

10. The use of a dispersion according to claim 6 or granules according to claim 9 in which is resistant to scratching transparent coatings.



 

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21 cl, 2 tbl

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FIELD: chemistry.

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9 cl, 5 tbl

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20 cl, 5 tbl, 13 ex

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13 cl, 23 ex, 2 tbl

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25 cl, 11 tbl

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67 cl, 33 ex

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2 tbl, 4 ex

FIELD: chemistry.

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13 cl, 4 tbl, 1ex

Pigment dispersion // 2455326

FIELD: chemistry.

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20 cl, 5 tbl, 13 ex

FIELD: nanotechnologies.

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20 cl, 1 tbl, 2 ex

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SUBSTANCE: invention can be used to produce magnesium chloride, silica and red pigment. Serpentinite calcined at 680-750°C is treated with 4-8% hydrochloric acid solution with weight ratio of serpentinite to hydrochloric acid equal to 1:(15-40). The hot pulp is then decanted and filtered. The residue is dried to obtain silica, the filtrate is evaporated and silicic acid is separated. After separating silicic acid in form of sol-gel, hydrochloric acid is added to a solution containing magnesium and iron (III) chlorides until 4-8% hydrochloric acid solution is obtained. The obtained hydrochloric acid solution is used to treat a new portion of serpentinite. Further, the decantation, filtration, evaporation of filtrate, separation of silicic acid and treatment of the obtained solution with hydrochloric acid are repeated 3-5 times using new portions of calcined serpentinite. The solution concentrated that way at 90°C is mixed with serpentinite and filtered. Magnesium chloride is separated from the residue which contains iron (III) hydroxide. Said residue is treated at 350-400°C to obtain red pigment.

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1 dwg, 1 ex

The invention relates to a method of sililirovanie SmartEncoding inorganic oxides and vysokonapornoj pyrogenic silicic acid obtained by this method, which is used as a thickener in polar systems, as an absorbent for oils, to improve the flowability of the toner, and antispywares

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19 cl, 1 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention relates to production of novel nanosized silica nanofiller materials for different polymer matrices. The modified organo-inorganic molecular silica sols of general formula: [SiO2]n[SiO1,5(CH2)3NRC(O)-Alk]m (I), where R denotes H or CH3; n is an integer from 40 to 20000; m is an integer from 20 to 10000; Alk is a C9-C17 hydrocarbon radical. The method of producing the modified organo-inorganic molecular silica sols involves first carrying out polycondensation of tetraethoxysilane in anhydrous acetic acid to obtain a given value of molecular weight of the inorganic part of the molecule, followed by addition of alkylamide trialkoxysilane into the reaction mixture, selected from alkylamide trialkoxysilanes of general formula: (R'O)3Si(CH2)3NRC(O)-Alk (II), where R and Alk assume values given above; R' denotes CH3- or C2H5-.

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9 cl, 2 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a sol containing silicon dioxide based particles, preparation and use thereof. The sol contains silicon dioxide based particles with axial ratio of at least 10 and specific surface area of at least 600 m2/g. The invention also relates to a sol containing silicon dioxide based particles with axial ratio of at least 10 and S-value approximately not higher than 25%. The invention also relates to a method of making paper, where a sol containing silicon dioxide based particles is used as an agent for increasing dehydration and retention of filler.

EFFECT: disclosed colloidal solutions (soles) have improved working characteristics for dehydration and retention of filler, as well as high stability of surface area with very small surface areas and content of SiO2.

27 cl, 15 tbl, 25 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and can be used to produce silicon oxide compounds doped with aluminium and rare-earth elements which are used in quartz and optical glass manufacturing and in fibre optics for making laser and luminescent glass. A solution of salts of rare-earth elements and an aluminium-containing compound are simultaneously added to an alkaline solution of tetraalkoxy silane with pH 7.5-9.0. The reaction mixture is intensely stirred at temperature 10-60°C. The formed sol is evaporated at temperature not higher than 100°C to a powdered state. The salts of rare-earth elements used are corresponding nitrates, chlorides or acetates. Isopropylate or aluminium fluoro-butylate is used as the aluminium-containing compounds.

EFFECT: invention enables to obtain highly-pure homogeneous powder not containing carbonaceous inclusions.

4 cl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in machine building and power engineering when making components for gas-turbine engines. The environmental protection coating (10) for components, containing silicon, having a first coefficient of thermal expansion, contains a silicon levelling layer (30) which is bound with at least part of the outer surface of the component. An intermediate layer (25, 27, 29) is bound with the silicon levelling layer (30) and has a second coefficient of thermal expansion matched with the first coefficient of thermal expansion. The intermediate layer (25, 27, 29) has a common composition RE2Si2O7. The protective layer (36) is bound with the intermediate layer (25, 27, 29) and has a common composition RE2SiO5. Destruction-resistant surface layer (35) has a surface layer (38) bound with the protective layer (36). The surface layer (38) contains RE and has ratio of RE to oxygen equal to at least 2:3. RE is at least one element from Y, Tb, Dy, Ho, Er, Tm, Yb, Lu. Thickness of the intermediate layer (25, 27, 29) is approximately equal to 0.0762-0.254 mm. Thickness of the destruction-resistant surface layer (35) is equal to approximately 0.0127-0.0508 mm.

EFFECT: high resistance of the component to water vapour and oxidation.

10 cl, 1 dwg, 1 tbl

FIELD: chemistry.

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EFFECT: invention enables to obtain silicon oxide sol with low content of sodium oxide which do not turn into gel-like state and do not form sediments during storage.

7 cl, 1 tbl, 3 ex

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