Columnar zinc oxide particles and method of obtaining thereof

FIELD: chemistry.

SUBSTANCE: invention relates to particles of zinc oxide, increasing heat conductivity or electric conductivity. The particles are represented by the following formula (1): ZnMn+xO1+nx/2 · aH2O (1), where Mn+ stands for a trivalent or tetravalent metal, x and a satisfy the ratio 0.002<x<0.05 and 0≤a<0.5, respectively, n stands for metal valence. The particles are characterised by a content of columnar particles 80% or higher. Also claimed are: method of obtaining the zinc oxide particles, burnt particles (A) and (B), resin compositions (A) and (B).

EFFECT: invention makes it possible to obtain the zinc oxide particles, used for an improvement of electric conductivity or heat conductivity of resins.

13 cl, 12 dwg, 5 tbl, 3 ex

 

The technical field to which the invention relates

The present invention relates to new particles of zinc oxide. More specifically, it refers to the columnar particles of zinc oxide, suitable for use as an additive for improving thermal conductivity, or additives that improve the electrical conductivity.

The level of technology

It is common practice to introduce into the resin composition containing rubber or plastic, various additives for improving the physical properties of the resin compositions.

For example, as additives to improve thermal conductivity, use crystalline silicon oxide, magnesium oxide, boron nitride, aluminum nitride, aluminum oxide, beryllium oxide, etc. as additives that improve the electrical conductivity, use tin oxide, zinc oxide, carbon black, titanium oxide coated with tin oxide, etc. is Well known that to make the song good conductivity it is necessary to enter in the composition of a large number of additives that improve the electrical conductivity, so that these additives are in contact with each other, and expensive additives that improve the electrical conductivity, have restrictions in use. Carbon black is an inexpensive additive that improves the conductivity, however, its use is limited, where for example black color is t, and at the stage of molding he sometimes wakes up and spoils the production site. As improving the electrical conductivity additive, which is mixed with a resin composition, we need to improve the conductivity additive white color, which allows you to use any desired color of the base material.

Therefore, zinc oxide, which is relatively cheap, non-toxic and chemically stable, have recently become widely used as an additive for improving thermal conductivity, or additives that improve the electrical conductivity.

In recent years, because of functional composite materials is growing interest in improving the physical properties of the additives have been improved, have conducted various studies are not only functional properties of additives that improve the physical properties of the material, but also forms of these supplements.

Zinc oxide may be in the form of spheres, array, plates, flakes, needles, tetrapods, sea urchins or ultrafine particles. Of these, the zinc oxide in the form of needles or tetrapods, which are considered to be easily formed in the resin compositions of the mesh structure, even when used in small quantities, it is proposed as an additive for improving thermal conductivity, or additives that improve the electrical conductivity.

For example, in patent documents 1, 2 and 3 is predlagajutsja particles of zinc oxide, obtained by mixing needle-shaped zinc oxide with an additive, such as Al, Ge, Ga, Sn and In, and subsequent restorative firing the mixture. However, these particles of zinc oxide are thin needles and easily broken during mixing with the resin. Broken particles worse form the mesh structure in the resin composition, they cannot fully realize the property of electrical conductivity or thermal conductivity.

In addition, in patent document 4 is disclosed a method of obtaining particles of zinc oxide in the form of fine powder, whereby an aqueous solution containing a water-soluble zinc salt and a water-soluble salt of the metal, which can be converted to aluminum oxide, gallium oxide or indium oxide, neutralized with alkali or alkaline carbonate order to obtain precipitated together product, this product is subjected to preliminary firing, and then calcined at a temperature of from 600 to 1000°C in nitrogen atmosphere. However, since the particles obtained in this way are in the form of fine powder and too small size, their conductivity is insufficient.

In patent document 5 proposes a method, in accordance with which the aluminum particles and particles of zinc oxide with an average diameter of from 0.1 to 5 μm are used in combination as additives to improve thermal conductivity.

Ka is indicated above, as additives that improve the electrical conductivity, or additives that improve thermal conductivity, it is proposed to use particles of zinc oxide in the form of needles or fine powder. However, if we take into account the resistance to fracture during mixing with the resin, and the ability to form in the resin mesh structure, the ideal form of zinc oxide is columnar, and not needle-like or powder.

(Patent document 1) JP-A 3-60429

(Patent document 2) JP-A 5-17298

(Patent document 3) JP-A 7-2519

(Patent document 4) JP-62-35970

(Patent document 5) JP-A 2005-64281

The invention

Therefore, the present invention is the provision of the columnar particles of zinc oxide that is resistant to breaking during introduction into the mixture and mixing with the resin and give it sufficient conductivity or electrical conductivity. In addition, another objective of this invention is the provision of a method of obtaining the above columnar particles of zinc oxide. Another objective of the present invention is the provision of a resin composition containing the columnar particles of zinc oxide and superior in thermal conductivity or electrical conductivity.

The author of the present invention conducted diligent research on finding ways recip is of columnar particles of zinc oxide. In the result, it was found that when an aqueous solution containing a zinc salt and an aqueous solution of compounds of alkali metal (s) react with each other, 80% or more formed after hydrothermal treatment of the particles have a columnar shape, if the number of connections of the alkali metal (C) relative amount of zinc is less than the equivalent weight, and if the pH of the reaction is neutral. Also it was found that the thus obtained columnar particles resistant to fracture and retain their shape, without being destroyed during introduction into the mixture and mixing with the resin; thus took place the present invention.

That is, the present invention provides particles of zinc oxide, represented by the following formula (1):

ZnMn+xO1+nx/2· aH2O(1)

where Mn+means trivalent or tetravalent metal, x and satisfy the ratio of 0.002<x<0.05 and 0≤a<0.5 a, respectively, n denotes the valence of the metal, and characterized by the content of the columnar particles is 80% or more.

In addition, the present invention provides a method of obtaining these particles of zinc oxide, which involves the following stages:

(I) reaction of an aqueous solution, the salt containing a series of zinc (a) and a salt of trivalent or tetravalent metal (b), with a water solution containing a compound of an alkali metal (s), so that the pH of the reaction mixture after the reaction is from 5.0 to 7.0,

(II) washing the thus obtained particles,

(III) emulsification washed particles and their subsequent hydrothermal treatment, and

(IV) drying of past hydrothermal processing of particles.

The present invention is provided calcined particles (A)obtained by firing the above-described particles of zinc oxide at a temperature of from 300 to 1100°C in non atmosphere. In addition, the present invention includes a resin composition (A)containing 100 weight. resin parts and from 150 to 400 weight. parts of these calcined particles (A).

In addition, the present invention is provided calcined particles (B)obtained by firing the above-described particles of zinc oxide at a temperature of from 300 to 1100°C in reducing atmosphere. In addition, the present invention includes a resin composition (C)containing 100 weight. resin parts and from 200 to 400 weight. parts of these calcined particles (B).

Brief description of drawings

Figure 1 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 1 of example 1.

Figure 2 is a obtained by scanning electron micro is Kobe image of the columnar particles of zinc oxide, formed in synthesis example 2 example 1.

Figure 3 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 3 example 1.

Figure 4 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 4 example 1.

Figure 5 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 5 example 1.

6 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 6 example 1.

Fig.7 is a obtained by scanning electron microscope image of the columnar particles of zinc oxide formed in synthesis example 7 example 1.

Fig is a obtained by scanning electron microscope image of the cubic particles of zinc oxide formed in comparative synthesis example 1 of example 1.

Fig.9 is a obtained by scanning electron microscope image of the cubic and columnar particles of zinc oxide formed in comparative synthesis example 2 example 1.

Figure 10 is polucen the e scanning electron microscope image of the needle-shaped particles of zinc oxide, formed in comparative synthesis example 3 example 1.

11 is a obtained by scanning electron microscope image of the cubic and columnar particles of zinc oxide formed in comparative synthesis example 4 example 1.

Fig represents x-ray diffraction of the columnar particles of zinc oxide obtained in example of synthesis 1 of example 1.

Description of the preferred option of carrying out the invention

The columnar particles of zinc oxide

Particles of zinc oxide of the present invention have a composition represented by the following formula (1):

ZnMn+xO1+nx/2· aH2O(1)

In the formula (1) Mn+means trivalent or tetravalent metal. Mn+covers Al3+, Ga3+In3+Ge4+, Fe3+, Cr3+, Cr4+and Ti4+. Preferably, Al3+or Fe3+.

Thus x satisfies the ratio of 0.002<x<0,05, preferably, of 0.004<x<0.02 and more preferably, 0,0065<x<0,01, and satisfies the relation 0≤a<10, more preferably 0≤a<0.5 in.

Columnar form

Each particle of the present invention has a columnar shape. In the context of this image is to be placed "columnar shape of the particles means, in regard at least to 10 particles in the field of view, magnified by a scanning electron microscope to 5000 diameters, the number of particles having an average size of 10 or less and an average degree of Stolbtsy in the range from 0.5 to 1 (the content of the columnar particles is 80% or more. The shape of each particle of the present invention is preferably in the form of a square column (column) or hexagonal columns.

The average size

In the context of the present invention, the average size is a ratio (L/D) length (L) of the column to the width (D) or the diameter of the Central part of the column. Length of column (L) and the width of the column (D) of the columnar crystal can be measured using a scanning electron microscope. When the length of column (L) and the width of the column (D) is large, the increase should be reduced so that the field of view was at least 10 particles, thus it is possible to measure the ratio of the size.

The average size is defined as the average value relationships sizes obtained on the basis of the measured length of column (L) and the width of the column (D) for 10 or more particles in the field of view, magnified with a scanning electron microscope diameters up to 1000 or more. The average size of the particles of the present invention is the provision of the equipment, from 1 to 10, more preferably from 2 to 6, even more preferably, from 5 to 6.

The average degree of Stolbtsy

The ratio (D2/D1) width (diameter) D2one end of the particle to the width (diameter) D1the other end of the particle represents the degree of Stolbtsy. In accordance with this definition, the particle with the degree of Stolbtsy close to 1, a bar, a particle with a degree of Stolbtsy close to 0, is the needle. The width of the column (D) of the columnar crystal can be measured using a scanning electron microscope. When the width of the column (D) is large, the magnification of a scanning electron microscope should be reduced so that the field of view was at least 10 particles, thus it is possible to measure the degree of Stolbtsy.

The average degree of Stolbtsy defined as the average value of the degree of Stolbtsy calculated for the width of the D1one end and the width of the D2the other end for 10 or more particles in the field of view, magnified with a scanning electron microscope diameters up to 1000 or more. The average degree of Stolbtsy particles of the present invention is, preferably, from 0.5 to 1, more preferably from 0.7 to 1.

The average length of the column of particles of the present invention is preferably from 0.5 to 20 μm, more is preferable, from 1 to 10 μm. The average width of a column of particles of the present invention is preferably from 0.25 to 1.5 μm, more preferably from 0.5 to 1 micron.

Particles of the present invention preferably have an average length of the pole from 0.5 to 20 μm, an average width of column from 0.25 to 1.5 μm, an average size of from 1 to 10 and an average degree of Stolbtsy from 0.5 to 1. More preferably, the particles of the present invention have an average length of the column from 1 to 10 μm, an average width of column from 0.5 to 1 μm, an average size of from 2 to 6 and an average degree of Stolbtsy from 0.7 to 1.

Specific surface area by BET (Brunauer-Emmett-teller) particles of the present invention is preferably from 1 to 10 m2/g, more preferably from 1 to 7 m2/year

A method of producing particles

The columnar particles of the zinc oxide of the present invention can be obtained through the following stages (I)-(IV).

Stage (I)

Stage (I) represents the stage at which an aqueous solution containing a salt of zinc (a) and a salt of trivalent or tetravalent metal (b), is reacted with an aqueous solution containing a compound of an alkali metal (s)used for co-deposition, so that the pH of the reaction mixture after the reaction is from 5.0 to 7.0, with the formation of the particles of the basic zinc compounds following formula (2):

ZnMn+x(OH)yAndm-(2+nx-y)/m· aH2O(2)

In the formula (2) Mn+, x and a are the same as in the formula (1).

y corresponds to a ratio of 1≤y≤1,6, preferably 1,1≤y≤1.5 times, more preferably 1,2≤y≤1,4. Am-means anion selected from the group consisting of Cl-, NO3-, SO42-and CO32-m indicates the valency of the anion.

Zinc salts (a)

Zinc salts (a), which is used as a material in this invention may be any salt of zinc, provided that it is soluble in water. For example, it may be selected from the group which includes zinc nitrate, zinc sulfate, zinc chloride and zinc acetate.

Salt of trivalent or tetravalent metal (b)

Salt of trivalent or tetravalent metal (b), which are used as additives include salts of aluminum, gallium, indium, germanium, iron (III), chromium, titanium, etc. i.e., can be used such metal salts, such as chlorides, nitrates, sulfates, carbonates, acetates, formate and oxalate of these metals. This salt, preferably selected from the group consisting of aluminum sulfate, aluminum chloride, aluminum nitrate, iron nitrate and NITR is the chrome.

Salt of trivalent or tetravalent metal (b), which is used as an additive, may be added to the reaction system after the formation of basic zinc compounds of the above formula (2), despite the fact that the number of additives in this case is quite low. Therefore, it is desirable to mix this salt with an aqueous solution of zinc salts (a) in advance.

When the adulteration of salts of trivalent or tetravalent metal (b) or when diluted aqueous solution of zinc salts may precipitate zinc hydroxide. Therefore, in an aqueous solution of zinc salts (a) in advance, you can add a small amount of inorganic acid. Added inorganic acid selected from hydrochloric acid, sulfuric acid, nitric acid, etc.

The amount of salt of trivalent or tetravalent metal (b), which is used as an additive, is adjusted so that its amount in the form of metal ions per mole of metal zinc constituted, preferably, from 0.002 to 0.05 mol, more preferably 0.005 to 0.01 mol. When the amount of metal salt (b) is too small, columnar crystals grow poorly, which is undesirable. When it is too large, a large number of compounds hydrotalcite, which is also undesirable.

The connection of the alkali metal (C)

Compounds is their alkali metal (s), which is used as a material includes sodium hydroxide, potassium hydroxide, ammonia, urea, sodium carbonate, sodium bicarbonate, etc. Preferably, it is sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate.

Reaction

During this reaction an aqueous solution containing a compound of an alkali metal (s)may be added to aqueous solution containing a salt of zinc (a) and a salt of trivalent or tetravalent metal (b), and Vice versa. Either of these two water solution can be simultaneously added to the reaction vessel containing water.

For co-deposition during this reaction it is necessary to adjust the pH of the reaction near neutral values. the pH of the reaction is preferably from 5.0 to 7.0, more preferably 5.0 or more, but less than 7.0, even more preferably from 5.5 to 6.5. the pH of the reaction depends on the amount of added alkali. When the pH of the reaction above 7,0 that it is undesirable that the content of the columnar particles after hydrothermal treatment becomes 50% or less. When the pH of the reaction below 5.0, undesirable, reduced output.

When the equivalent weight fraction of alkali (molar ratio of [NaOH]/[ZnCl2]) in the reaction is small, there are a large number of anions, which is an impurity in the main compound of zinc, and during firing is formed Bo is lsoe amount of acidic gas. When add 2 mol of alkali, which constitute the equivalent weight 1 pray zinc, pH of the reaction becomes equal to 12 or more, and zinc at such a high pH can be dissolved again, as it is an amphoteric element. To regulate the pH of the reaction near neutral values, the amount of alkali per mole of zinc, preferably, should be equal to from 1 to 1.6 mol, more preferably from 1.1 to 1.5 mol, most preferably, from 1.2 to 1.4 mol. The reaction temperature preferably is in a range from 10 to 60°C.

Stage (II)

Stage (II) is a stage leaching of the above-described particles. In the suspension resulting from this reaction contains a large amount of salts, so they should be removed by washing the particles with water.

Stage (III)

Stage (III) is a stage in which the washed particles emuleret, and then subjected to hydrothermal treatment. During the emulsification washed particles suspended in deionized water, and then the slurry is subjected to hydrothermal treatment. The temperature of the hydrothermal treatment is preferably from 100 to 170°C., more preferably from 150 to 170°C. the Hydrothermal treatment is carried out, preferably, from 2 to 24 hours, more preferably from 12 to 20 hours. When the temperature of gidrotermicheskogo below 100°C, what is undesirable, there is no sufficient crystal growth, or you cannot get the columnar crystals. In addition, even when the temperature of the hydrothermal treatment is set to 170°C or above, changes in the crystal growth does not occur. By such hydrothermal treatment receive columnar particles of zinc oxide. Thus obtained particles partially contain the primary connection of zinc or a compound of hydrotalcite.

Stage (IV)

Stage (IV) is a stage of drying of past hydrothermal processing of particles. Drying can be carried out in the dryer with natural circulation, the dryer is heated by hot air, etc. are Sufficiently dried particles at a temperature of from 105 to 120°C for 10 to 20 hours.

The calcined particles (A)

The calcined particles (A) of the present invention can be represented by the following formula (3):

ZnMn+xO1+nx/2(3)

In the formula (3) Mn+and x are the same as in the formula (1). The form of sintered particles (A) is the same as in the columnar particles of the zinc oxide of the formula (1).

The calcined particles (A) of the present invention can be obtained by firing the columnar particles of the zinc oxide of the above formula (1) in prisutstvie the non gas at a temperature of from 300 to 1100°C, preferably, from 600 to 900°C. in Atmospheric air, helium, oxygen, nitrogen, etc. are examples of non gas. As a device for roasting can be used for any intended for firing the device, provided that it enables the heating and firing at a temperature of from 300 to 1100°C. specific examples of such devices include Converter, open hearth furnace, rotary oven, tunnel oven, muffle furnace, etc.

The calcined particles (A) of the present invention can be used as an additive for improving thermal conductivity. In addition, the calcined particles (A) of the present invention can be used as an additive for improving thermal conductivity, in combination with other additives that enhance thermal conductivity, such as magnesium oxide, boron nitride, aluminum nitride, aluminum oxide and crystalline silica.

The resin composition (A)

The resin composition (A) of the present invention contains 100 weight. resin parts and from 150 to 400 weight. parts of calcined particles (A). The content of the calcined particles (A) per 100 weight. resin parts is preferably from 100 to 500 weight. parts, more preferably from 150 to 400 weight. parts.

Resin include polyolefin resins such as polyethylene, polypropylene and polystyrene, vinyl resins, such to the to polyvinyl chloride and a copolymer of ethylene-vinyl acetate, complex polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 6,6, simple polyester resin, such as Polyphenylene oxyde, acrylic resins such as polymethyl methacrylate, the synthetic rubbers such as styrene-butadiene rubber and Acrylonitrile-butadiene rubber, phenolic resins such as phenol-formaldehyde resin, epoxy resin, such as epoxy resin of bisphenol a type epoxy resin of the novolak type, silicone rubber, natural rubber (any suitable molecular weight), polyimide resin, polyster, ABS plastic, etc.

Resin and sintered particles (A) can be mixed using any mixing device, such as elasticator, a universal mixer, a rotating cylinder, etc. For mixing, it is preferable to apply the method of extruding the resin composition in the form of filaments by means of plasticators continuous action, which are then cut, receiving granules.

The resin composition (A) of the present invention provides unsurpassed heat conductivity and can be used as a material for the manufacture of the cooling fins of heat-generating parts such as transistor high power thyristor, rectifier, transformer, heater and integrated circuit.

Present from Britanie includes a method of increasing thermal conductivity of the resin composition (A), obtained by adding the calcined particles (A) to the resin. In addition, the present invention encompasses the use of the calcined particles (A) as to improve the conductivity of the additive to the resin.

The calcined particles (B)

The formula for the composition of the calcined particles (B) of the present invention similar to the above formula (3).

The form of sintered particles (C) is the same as that of the columnar particles of the zinc oxide of the formula (1).

The calcined particles (B) of the present invention can be obtained by firing the columnar particles of the zinc oxide of the above formula (1) in the presence of a reducing gas at a temperature of from 600 to 1000°C., preferably from 700 to 900°C. Hydrogen, carbon monoxide, etc. are examples of the reducing gas. As a device for roasting can be used for any intended for firing the device, provided that it enables the heating and firing at a temperature of from 600 to 1000°C. specific examples of such devices include Converter, open hearth furnace, rotary oven, tunnel oven, muffle furnace, etc. Calcined particles (B) of the present invention can be used as increasing the conductivity of the additive in combination with other improves the conductivity additives, such as commonly used ELEH tropology zinc oxide.

The resin composition (C)

The resin composition (C) of the present invention contains 100 weight. resin parts and from 200 to 400 weight. parts of sintered particles (In). The content of the calcined particles (B) per 100 weight. resin parts is preferably from 100 to 500 weight. parts, more preferably from 200 to 300 weight. parts.

Resin include polyolefin resins such as polyethylene, polypropylene and polystyrene, vinyl resins such as polyvinyl chloride and a copolymer of ethylene-vinyl acetate, a complex polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 6,6, simple polyester resin, such as Polyphenylene oxyde, acrylic resins such as polymethyl methacrylate, the synthetic rubbers such as styrene-butadiene rubber and Acrylonitrile-butadiene rubber, phenolic resins such as phenol-formaldehyde resin, epoxy resin, such as epoxy resin of bisphenol a type epoxy resin type novolak, silicone rubber, natural rubber (any suitable molecular weight), polyimide resin, polyster, ABS plastic, etc.

Resin and sintered particles (B) can be mixed using any mixing device, such as elasticator, universal stirrer and a rotating cylinder. For mixing, preferably, applied methods for the extrusion of the resin composition in the form of filaments by means of plasticators continuous action, which are then cut, receiving granules.

The resin composition (C) of the present invention is unsurpassed electrical conductivity and can be used as an additive for preventing the accumulation of static electricity on electrical parts, or as an additive for improving the conductivity, in the compositions of conductive floor coverings.

The present invention includes a method of increasing the electrical conductivity of the resin composition (C)obtained by adding the calcined particles (B) to the resin. In addition, the present invention encompasses the use of the calcined particles (B) as to improve the conductivity of the additive to the resin.

Surface treatment

The columnar particles of the zinc oxide of the formula (1), the calcined particles (a) and annealed particles (In)provided by the present invention, preferably, have on each of its surfaces, at least one coating selected from the group comprising higher fatty acids, esters of phosphoric acid, esters of fatty acids and polyhydric alcohols, anionic surfactants (surfactant) and a binder on the basis of silane, titanate, and aluminum. Due to the presence of such a coating improves their ability to mixing with the resin or rubber.

For example, use at least one of the components is NT selected from the group consisting of higher fatty acids, anionic surfactants, esters of phosphoric acid, binding agents (silane-based, titanate and aluminum) and esters of polyhydric alcohols and fatty acids.

To the higher fatty acids include higher fatty acid containing 10 or more carbon atoms, such as stearic acid, erucic acid, palmitic acid, lauric acid, Bekenova acid and salts of these acids and alkaline metals.

For anionic surfactants include salts of esters of sulfuric acid and higher alcohols such as stearyl alcohol and alerby alcohol, salt of ester of sulfuric acid and polietilenglikoli simple ester, salts of esters of sulfuric acid with amide bonds, salts of esters of sulfuric acid with ester bonds, sulfonates with ester bonds, salts of sulfonic acids with amide bonds, salts of sulfonic acids with simple ether bonds, salt alkylarylsulfonates acid with ether bonds, salt alkylarylsulfonates acid amide bonds and so on; to the phosphoric esters include mono - and diesters of orthophosphoric acid and alcohol olejowego, stearyl alcohol, etc. and their mixtures or their salts of acidic or alkaline type or amine salt.

Glue substances on the basis of silane include γ-chloropropyl amoxicilan, vinyltrichlorosilane, vinyltriethoxysilane, VINYLTRIMETHOXYSILANE, vinyl-Tris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropionylglycine, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-ureidopropionic etc.

Glue substances on the basis of titanate are isopropylthiazole the titanate, isopropyl-Tris(diastereotopic) titanate, isopropyl(N-amino-ethyl-amino-ethyl) titanate, isopropylbenzenesulfonyl the titanate, etc.

Glue substances on the basis of aluminum include diisopropylate acetoacetamide etc.

Esters of polyhydric alcohols and fatty acids include glycerylmonostearate, glycerylmonostearate etc.

The number of agent for surface treatment may be selected as needed, however, in accordance with the present invention, it is preferable to limit the specified amount relative to the weight of the columnar particles of the zinc oxide of the formula (1), the calcined particles (A) or sintered particles (In), approximately 10% of the weight. or less. The above-described particles with the processed surface can be converted into the form of the final product by implementing, for example, washing with water, dehydration, granulare the project, drying, comminution or classification, as appropriate.

The method of surface treatment of the above agent for surface treatment can be carried out as a dry method or wet method, essentially known. For example, a dry method may be carried out by adding an agent for surface treatment in the form of liquid, emulsion or solid material, while the columnar particles of zinc oxide or powder columnar particles of zinc oxide are thoroughly mixed using a mixing device such as a stirrer Henkel, and then thoroughly mixed under heating or without heating. The wet method can be carried out by adding the above agent for surface treatment in the form of a liquid or emulsion to the columnar particles of zinc oxide or suspension of the columnar particles of zinc oxide in alcohol, etc. and thorough mechanical mixing at a temperature up to about 100°C. the Number of agent for surface treatment relative to the weight of the columnar particles of zinc oxide is preferably from 0.1 to 10 wt%, more preferably, from 0.1 to 5 wt%.

Examples

Further, the present invention is specifically explained with reference to the examples below. The examples have used high-quality reagents supplied by Wako Pure hemical Industries, Ltd., if not stated otherwise. Properties were measured in the following ways :

Measuring instruments and methods of measurement

(1) Measurement of specific surface area by BET

Method: in accordance with method three points

Device: high-speed device for measuring the specific surface area/distribution then NOVA2000 (Yuasa Ionics, Inc.)

(2) Observation of the particles in the image obtained by scanning electron microscope

Device: scanning electron microscope (S-3000N (Hitachi)

Method: accelerating voltage 15 kV, a working distance of 10 mm

(i) the Content of the columnar particles

For at least 10 particles per field of view, increased to 5000 diameters using a scanning electron microscope, we measured the fraction of particles with an average size (%) 10 or less and an average degree of Stolbtsy in the range from 0.5 to 1.

(ii) the Average length of the column

For at least 10 particles per field of view, increased diameters up to 1000 or more using a scanning electron microscope, measured the length of a column (L)for which the expected average value.

(iii) the Average width of a column

For at least 10 particles per field of view, increased diameters up to 1000 or more using a scanning electron microscope, measured values of the width of the column (D), for which the expected average value is used.

(iv) the Average size

For at least 10 particles per field of view, increased diameters up to 1000 or more using a scanning electron microscope, the measured value of the length of a column (L) and the width of the column (D), was calculated the ratio of the size (L/D)values which were then averaged.

(v) the Average degree of Stolbtsy

For at least 10 particles per field of view, increased diameters up to 1000 or more using a scanning electron microscope, for each particle was measured width (diameter) D1one end and the width (diameter) D2the other end, used to calculate the degree of Stolbtsy (D2/D1), the values obtained were averaged.

(3) x-ray analysis

Device: x-ray spectrometer RINT2200N (manufactured by Rigaku Corporation)

Method: CU-α, angle (2θ): 5-65°, a step of 0.02°, scanning speed: 4°/min working voltage: 40 kV, working current: 20mV

(4) Measurement of thermal conductivity

Method: in accordance with the method of "hot buffet" ISO/CD22007-2

Device: a device for measuring the physical properties of hot materials TRA 501 (Kyoto Electronics Manufacturing Co., Ltd.): the sensor Φ7 mm RTK-7.

(5) measure the resistance powder

Method: the powder was pressed into pellets under a load of 200 kN using a BRIQUETTING PRESS BRE-30 (out by Maekawa), measurements were carried out by attaching the measuring tips of the samples is of IR chains (L-22/Yokokawa) to two points, located at a distance of 1 cm from each other.

(6) Measurement of specific volume resistance

Method: in accordance with the method controllable two-annular electrode (at 23°C and 50% relative humidity)

Device: R8340 (manufactured by ADVANTEST CORPORATION)

Example 1. Synthesis of columnar particles of zinc oxide

Example of synthesis 1

Reaction

To a liquid mixture of an aqueous solution of zinc chloride and an aqueous solution of aluminum sulfate with a concentration of zinc chloride 1,011 mol/l and the concentration of aluminum sulfate 0,00505 mol/l with stirring was added sodium hydroxide in an amount corresponding equivalent weight fraction of alkali 1,2, that is, to 1.2 mol of sodium hydroxide per mole of zinc chloride, the reaction mixture was carried out at 25°C for 30 minutes. the pH of the reaction suspension was 5,91.

Flushing

Thus obtained reaction suspension was washed with water.

Hydrothermal processing

The washed suspension re-suspended in deionized water and subjected to hydrothermal treatment at a temperature of 120°C for 15 hours.

Drying

Thus obtained product dehydrational, cleaned and dried, having a particle. In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a primary connection hydroxide is zinc using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. Particle properties are shown in table 1.

Example of synthesis 2

Particles obtained as in example of synthesis 1, except that the equivalent weights of alkali changed by 1.4, aluminum sulfate was replaced with a titanium sulfate (IV), and the conditions of the hydrothermal treatment were 170°C and 20 hours. In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. Particle properties are shown in table 1.

Example of synthesis 3

Particles obtained as in example of synthesis 1, except that the equivalent weights of alkali changed by 1.6, aluminum sulfate was replaced by acetate India (III). In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. The properties of the particles shown in the table 1.

Example of synthesis 4

Reaction

To a liquid mixture of an aqueous solution of zinc chloride, aqueous solution of aluminum sulfate and hydrochloric acid with a concentration of zinc chloride 1,458 mol/l, the concentration of aluminum sulfate 0,00417 mol/l and the concentration of hydrochloric acid of 0.025 mol/l with stirring was added the sodium hydroxide in the amount of 1.2 moles per mole of zinc chloride, the reaction mixture was carried out at 25°C for 30 minutes. the pH of the reaction suspension was 5,97.

Clean

The resulting reaction suspension was purified by washing with water.

Hydrothermal processing

The washed suspension re-suspended in deionized water and subjected to hydrothermal treatment at 170°C for 13 hours. Thus obtained product dehydrational, cleaned and dried, having a particle. Through x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. Particle properties are shown in table 1.

Example of synthesis of 5

Particles obtained as in synthesis example 4, except that the concentration of aluminum sulfate was changed to 0,0073 m the l/l and was replaced with aluminum sulfate to nitrate gallium (III). In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. Particle properties are shown in table 1.

Example of synthesis 6

Reaction

To a liquid mixture of an aqueous solution of zinc chloride, aqueous solution of aluminum chloride and hydrochloric acid with a concentration of zinc chloride 1,458 mol/l, the concentration of aluminium chloride 0,0146 mol/l and the concentration of hydrochloric acid of 0.025 mol/l with stirring was added the sodium hydroxide in the amount of 1.4 mol per mole of zinc chloride, the reaction mixture was carried out at 40 ° C for 30 minutes. the pH of the reaction suspension was 6,03.

Clean

The resulting reaction suspension was purified by washing with water.

Hydrothermal processing

The washed suspension re-suspended in deionized water and subjected to hydrothermal treatment at 170°C for 13 hours.

Drying

Thus obtained product dehydrational, cleaned and dried. In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of zinc oxide with a primary connection hydrox is Yes zinc, it was also recorded that their specific surface area by BET is 3.1 m2/g, using images obtained by scanning electron microscope, found that the particle is a columnar crystal with the length of the pole from 0.6 to 3.8 μm, the width of the column from 0.25 to 0.35 μm, the ratio of sizes from 2 to 10,86 and degree of Stolbtsy from 0.73 to 0.89 as.

Example of synthesis of 7

Reaction

To a liquid mixture of an aqueous solution of zinc chloride, an aqueous solution of iron nitrate and hydrochloric acid with a concentration of zinc chloride 1,458 mol/l, the concentration of iron nitrate 0,0073 mol/l and the concentration of hydrochloric acid of 0.025 mol/l with stirring was added the sodium hydroxide in the amount of 1.4 mol per mole of zinc chloride, the reaction mixture was carried out at 25°C for 1 hour. the pH of the reaction suspension was 6,02.

Clean

The resulting reaction suspension was purified by washing with water.

Hydrothermal processing

The washed suspension re-suspended in deionized water and subjected to hydrothermal treatment at 170°C for 13 hours.

Drying

Thus obtained product dehydrational, cleaned and dried. The analysis of the obtained particles by x-ray diffraction analysis, it was found that the particles were a mixture of zinc oxide the main connection of zinc hydroxide, it was also recorded that their specific surface area by BET is 7.0 m2/g, using images obtained by scanning electron microscope, found that the particle is a columnar crystal with the length of the pole from 0.76 to 3,95 mm, a width of the pole from 0.25 to 0.5 μm, the ratio of sizes from 3.03 to 9,88 and degree of stanchest of 0.83 to 0.96.

Comparative synthesis example 1

Particles obtained as in example of synthesis 1, except that the equivalent weights of alkali changed 1.65. In the x-ray diffraction analysis, it was found that the thus obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a columnar crystal. Particle properties are shown in table 1.

Comparative synthesis example 2

Particles obtained as in example of synthesis 1, except that the equivalent weights of alkali changed on 1,70. In the x-ray diffraction analysis, it was found that the thus obtained particles were a mixture of columnar crystals form and crystals cubic shape. Particle properties are shown in table 1.

Comparative synthesis example 3/p>

Reaction

To a liquid mixture of an aqueous solution of zinc chloride and an aqueous solution of aluminum sulfate with a concentration of zinc chloride 1.05 mol/l and the concentration of aluminum sulfate 0,00525 mol/l with stirring was added simultaneously an aqueous solution of sodium carbonate with a concentration of 0,746 mol/l and 1,096 N sodium hydroxide so that the amount of sodium carbonate per mole of zinc chloride was 0.005 mol, and the amount of sodium hydroxide per mole of zinc chloride was 2 mol, the reaction mixture was carried out at 40°C for 30 minutes. the pH of the reaction suspension was 8,63.

Clean

The resulting reaction suspension was purified by washing with water.

Hydrothermal processing

The washed suspension re-suspended in deionized water and subjected to hydrothermal treatment at 170°C for 13 hours.

Drying

Thus obtained product dehydrational, cleaned and dried, having a particle. Through x-ray diffraction analysis, it was found that the thus obtained particles were a mixture of zinc oxide with a basic compound of zinc hydroxide, using images obtained by scanning electron microscope, discovered that each particle is a needle crystal. Particle properties are shown in table 1.

Against the positive example of synthesis 4

Particles obtained as in synthesis example 4, except that aluminum sulfate was added. In the x-ray diffraction analysis, it was found that the obtained particles were a mixture of columnar crystals and cubic crystals of zinc oxide. Particle properties are shown in table 1.

Table 1
PS 1PS 2PS 3PS 4PS 5PS 6PS 7
[ZnO/[Al2O3]200200200350200200200
Salt - additiveAl2(SO4)3Ti(SO4)2In(CH3COO)3Al2(SO4)3Ga(NO3)3AlCl3Fe(NO3)3
x in the formula (1)0,010,010,010,00570,010,010,01
Equivalent weight fraction of alkali1,21,21,61,21,21,41,4
pH after reaction5,916,126,925,97of 5.816,036,02
Conditions of the hydrothermal treatment120°C, 12 h170°C for 20 h120°C, 12 h170°C 13 h170°C 13 h170°C 13 h170°C 13 h
Specific surface area by BET, m2/g3,13,44,11,61,3 3,17,0
The shape of the particlesColumnColumnColumnColumnar CubicColumnColumnColumn
The content of the columnar particles, %80,085,085,082,085,080,080,0
The average length of the post, mcm4,607,38the 3.652,334,902,202,36
The average width of a column, mcm0,750,750,650,380,750,300,38
The average size5,7010,135,71 2,135,95to 6.436,46
The average degree of Stolbtsy0,810,880,840,820,810,810,90
PS - example synthesis

Equivalent weight fraction of alkali
Table 1 (continued)
PCA 1PCA 2PCA 3PCA 4
[ZnO/[Al2O3]200200200-
Salt - additiveAl2(SO4)3Al2(SO4)3Al2(SO4)3-
x in the formula (1)0,010,010,010
1,651,72,0251,2
pH after reaction8,16of 10.218,635,947
Conditions of the hydrothermal treatment120°C, 12 h120°C, 12 h170°C 13 h170°C 13 h
Specific surface area by BET, m2/g6,24,82,33,1
The shape of the particlesColumnColumnar CubicNeedleColumnar Cubic
The content of the columnar particles, %5,050,00,025,0
The average length of the post, mcm0,340,742,33
The average width of a column, mcm0,240,240,120,25
The average size1,092,6430,001,59
The average degree of Stolbtsy0,800,920,200,92
PCA - comparative synthesis example

Example 2. Getting burnt particles (A)

The particles obtained in example 1 was subjected to annealing under the conditions shown in table 2, to obtain sintered particles (A)-1-(S)-4, suitable for use as additives to improve thermal conductivity. In addition, were obtained comparative calcined particles (A)-5 and (S)-6. These particles were then subjected to surface treatment using agents for surface treatment shown in table 2.

td align="center"> 5,0
Table 2
The calcined particles (A)-1Objgen the e particles (A)-2 The calcined particles (A)-3The calcined particles (A)-4The calcined particles (A)-5The calcined particles (A)-6
Zinc oxidePS 2PS 3PS 4PS 7PCA 2PCA 3
Conditions roastingthe surrounding atmosphere
400°C
4 h
the surrounding atmosphere
800°C
2 hours
the surrounding atmosphere
700°C
2 hours
the surrounding atmosphere
1100°C
2 hours
the surrounding atmosphere
800°C
2 hours
the surrounding atmosphere
800°C
2 hours
Agent for surface treatmentNilThe sodium oleateVinyltrichlorosilaneSodium stearateNilSodium stearate
The number of agent for surface treatment, % weight. regarding zinc oxide-5,00,1-0,1
PS - the example of synthesis; ATP - comparative synthesis example

Example 3. A composition of heat-conducting resin

Burnt particles of one type (A)-1-(A)-6 reflected in table 2, and mass-produced zinc oxide (for comparison) in amounts shown in table 3, were mixed with 100 weight. parts industrial silicone polymer (product name: TSE201/GE Toshiba Silicones), then all mixed in plasticators within 1 hour (23 rpm and an initial temperature of 25°C). Then added curing agent (product name: TC-8/GE Toshiba Silicones), and the mixture was stirred in a similar way within 20 minutes. As commercially available zinc oxide used zinc oxide (product name: 23-K/Hakusui Tech Co., Ltd.) and zinc oxide (product name: #1/Seido Chemical Industry Co., Ltd.).

Thus obtained resin composition was subjected to pressing at 160°C to form the sheet with a diameter of 30 mm and a thickness of 8 mm and subsequent curing in an oven at s the purpose of obtaining samples for testing. Measured the conductivity of each sample at 300°C by the method of "hot disk". The results are presented in table 3.

Table 3
TA resin 1TA resin 2TA resin 3TA resin 4TA resin 5TA resin 6
Composition, % (parts per 100 parts resin)Organosilicon polymer100100100100100100
The calcined particles (A)-1350150---200
The calcined particles (A)-2--350---
The calcined particles (A)-3---400--
Annealed particle is (A)-4 ----350-
The calcined particles (A)-5 (for comparison)------
The calcined particles (A)-6 (for comparison)------
Zinc oxide And (for comparison)-----200
Zinc oxide (for comparison)------
Hardening agents (for comparison)1,81,81,01,8 1,81,8
thermal conductivity, In/m·K1,161,111,101,131,031,24
Color sheetpale-yellowwhitepale-yellowpale-yellowpale-yellowpale-yellow
TA resin - conductive resin

Table 3 (continued)
TA resin 7TA resin 8TA resin 9*TA resin 10*TA resin 11*TA resin 12*
Composition, %Organosilicon polymer100100100100100 100
The calcined particles (A)-1-200----
The calcined particles (A)-2------
The calcined particles (A)-3200-----
The calcined particles (A)-4-100----
The calcined particles (A)-5 (for comparison)--400---
The calcined particles (A)-6 (for comparison)100-- 400--
Zinc oxide And (for comparison)100---350-
Zinc oxide (for comparison)-100---350
Hardening agents (for comparison)1,81,81,81,81,81,8
thermal conductivity, In/m·K1,261,180,970,800,970,87
Color sheetpale graypale graypale-yellowgreygreygrey
TA resin - conductive resin; * to compare

In table 3, when comparing the conductive resin 1-5 with heat-conducting resin 10-12, it can be seen that the resin containing the calcined particles (A) of the present invention have a higher thermal conductivity than the resin containing the usual needle-like zinc oxide or zinc oxide, commercially available.

In addition, when using the calcined particles (A) of the present invention in conjunction with zinc oxide, manufactured in series, as in heat-conducting resin 6-8, the effect of increasing thermal conductivity is not reduced.

It is believed that this effect is a consequence of the fact that the calcined particles (A) of the present invention hardly break down during mixing, so burnt particles (A) with high probability will be in contact with each other in the resin composition.

Example 4 Obtaining calcined particles (B)

The compound obtained in example 1 was subjected to the regenerative firing conditions shown in table 4, to obtain sintered particles (In), suitable for use as additives that improve the electrical conductivity.

Table 4
The calcined particles (B)-1 The calcined particles (B)-2The calcined particles (B)-3The calcined particles (B)-4
Zinc oxidePS 1PS 2PS 4PS 5
Conditions roastingthe atmosphere of H2
700°C for 2 hours
the atmosphere of H2
900°C for 2 hours
the atmosphere of H2
900°C for 2 hours
the atmosphere of H2700°C for 2 hours
The resistance value of the powder, Ωof 3.2×104of 1.2×1045,3×104of 1.6×104
Agent for surface treatmentNilSodium stearateThe sodium oleateVinyltrichlorosilane
The number of agent for surface treatment, % weight. (as zinc oxide)-0,11,05,0
PS - example synthesis
Table 4 (continued)
The calcined particles (B)-5The calcined particles (B)-6The calcined particles (B)-7The calcined particles (B)-8
Zinc oxidePS 6PCA 1PCA 3PCA 4
Conditions roastingthe atmosphere of H21000°C 2 hoursthe atmosphere of H2800°C 2 hoursthe atmosphere of H2800°C 2 hoursthe atmosphere of H2800°C 2 hours
The resistance value of the powder, Ωof 1.4×104of 4.2×104of 1.4×1046,2×104
Agent for surface treatmentSodium stearateNilSodium stearateSodium stearate
The number of agent for surface treatment, % weight. (Rel is relatively zinc oxide) 0,1-0,10,1
PS - the example of synthesis; ATP - comparative synthesis example

Example 5 the composition of the conductive resin

The calcined particles of the same (In)-1-(In)-8 reflected in table 4, and mass-produced zinc oxide (for comparison) in amounts shown in table 5, was mixed with 100 weight. parts of linear low density polyethylene, obtained by gas-phase method (product name: NOVATEC LL UF240/production Japan Polyethylene Corporation), and measured their own specific volume resistance of each of the thus obtained composition. The results are presented in table 5. Zinc oxide and zinc oxide In is the same as zinc oxide and zinc oxide, used in example 3.

In particular, granules specified low-density polyethylene was placed in a gear oven and pre-heated at C within 30 minutes, the molten pellets with stirring using a roller connected with the burnt particles (In). Then plastilinovyy product was subjected to pressing at 190°C. to form the sheet thickness of 2 mm with the purpose of obtaining a sample for testing.

-
That the face 5
EP resin 1EP resin 2EP resin 3EP resin 4EP resin 5EP resin 6
Composition, %LLDPE100100100100100100
The calcined particles (B)-1300200----
The calcined particles (B)-2--300---
The calcined particles (B)-3---300--
The calcined particles (B)-4---300-
The calcined particles (B)-5-----300
The calcined particles (B)-6 (for comparison)------
The calcined particles (B)-7 (for comparison)------
The calcined particles (B)-8 (for comparison)------
Zinc oxide And (for comparison)------
Zinc oxide (for when Anania) ------
Own specific volume resistivity, Ω/cm1,166,79×1062,32×1058,21×106of 1.16×106of 4.54×105
Color sheetpale-yellowwhitepale-yellowpale-yellowpale-yellowpale-yellow
EP resin - conductive resin; LLDPE - linear low density polyethylene

tr>
Table 5 (continued)
EP resin 7*EP resin 8*EP resin 9*EP resin 10*EP resin 11*EP resin 12 EP resin 13
Composition, %LLDPE100100100100100100100
The calcined particles (B)-1----200200-
The calcined particles (B)-2------200
The calcined particles (B)-3----100-
The calcined particles (B)-4-------
The calcined particles (B)-5------
The calcined particles (B)-6*300------
The calcined particles (B)-7*-300-200---
The calcined particles (B)-8*--300----
Zinc oxide And*---100100--
Zinc oxide In* ------100
Own specific volume resistivity, Ω/cm1,50×1015of 3.33×10127,45×10152,60×10122,00×1061,20×1054,60×105
Color sheetpale-yellowpale-yellowpale-yellowgreygreypale-yellowgrey
EP resin - conductive resin; LLDPE - linear low density polyethylene; *to compare

As can be seen from table 5, the conductive resin 7 or 9 containing zinc oxide with an average size of less than 2, and conductive resin 8 and 10, the needle containing the oxides of zinc, characterized by its own specific volume resistance in the range from 1×1012up to 1×1016Ω, t is given as conductive resin 1-6, 12 and 13, containing the calcined particles (B) of the present invention, are characterized by their own specific volume resistance in the range from 1×105up to 1×107Ω.

If we take into account that there is a small difference in the resistance values of the powder for the first and second, as can be seen from table 4, it can be argued that the calcined particles (B) of the present invention hardly break down during mixing, so burnt particles (b) with high probability will be in contact with each other in the resin, giving it an appropriate own specific volume resistance.

The value of invention

The shape of the particles of the zinc oxide of the present invention, in contrast to the conventional column, so the particles do not break down during mixing with the resin, as acicular particles, and easy to form in the resin network structure. Consequently, particles of zinc oxide of the present invention is suitable for use as additives to improve thermal conductivity, or additives that improve the electrical conductivity. Particles of zinc oxide of the present invention may be present in the resin in a considerable amount. The columnar particles of the zinc oxide of the present invention have a lower hardness than the magnesium oxide or aluminum oxide, so the equipment etc. are not exposed to the abrasive is on wear. In addition, the columnar particles of the zinc oxide of the present invention are safe for human health and budget, so they have a wide range of applications.

These particles of zinc oxide can be produced in accordance with the method of producing particles of the present invention. The resin composition of the present invention has an excellent thermal conductivity or electrical conductivity.

Industrial applicability

Particles of zinc oxide of the present invention is suitable for use as additives that improve the properties of the resin compositions used for the manufacture of the cooling fins of heat-generating parts such as transistor high power thyristor, rectifier, transformer, heater and integrated circuit. They are also suitable for use as an additive for preventing the accumulation of static electricity on electrical parts, or as an additive for improving the conductivity, in the compositions of conductive floor coverings.

1. Increasing thermal conductivity or electrical conductivity of the particles of zinc oxide, represented by the following formula (1):

ZnMn+xO1+nx/2· aH2O(1)

where Mn+means Tr is valenty or tetravalent metal, x and a satisfy the ratio of 0.002<x<0.05 and 0≤a<0.5 a, respectively, n denotes the valence of the metal, and characterized by the content of the columnar particles is 80% or more.

2. Particles according to claim 1, which have the shape of a square pillar or a hexagonal column.

3. Particles according to claim 1, which have an average length of post from 0.5 to 20 μm, average width of a post from 0.25 to 1.5 μm, the average size of from 1 to 10 and the average degree of Stolbtsy from 0.5 to 1.

4. Particles according to claim 1, which have an average length of the column from 1 to 10 μm, average width of a post from 0.5 to 1 μm, the average size of from 2 to 6 and an average degree of Stolbtsy from 0.7 to 1.

5. Particles according to claim 1, having a specific surface area according to BET from 1 to 10 m2/year

6. Particles according to claim 1, which have on their surface at least one coating selected from the group comprising higher fatty acids, esters of phosphoric acid, esters of fatty acids and polyhydric alcohols, anionic surfactants and binders silane-based, titanate and aluminum.

7. A method of obtaining particles of zinc oxide according to claim 1, which includes stages:
(I) reaction of an aqueous solution containing a salt of zinc (a) and a salt of trivalent or tetravalent metal (b)with an aqueous solution containing a compound of an alkali metal (c), so that pH of the reaction is Messi at the end of the reaction is from 5.0 to 7.0,
(II) washing the thus obtained particles,
(III) emulsification washed particles and their subsequent hydrothermal treatment, and
(IV) drying of past hydrothermal processing of particles.

8. Increasing thermal conductivity of sintered particles (A)obtained by firing particles of zinc oxide according to claim 1 at a temperature of from 300 to 1100°C in non atmosphere.

9. The calcined particles (A) of claim 8, which have on their surface at least one coating selected from the group comprising higher fatty acids, esters of phosphoric acid, esters of fatty acids and polyhydric alcohols, anionic surfactants and binders silane-based, titanate and aluminum.

10. Heat-conducting resin composition (A)containing 100 weight. resin parts and from 150 to 400 weight. parts of calcined particles (a) item 8.

11. Increasing the conductivity of the annealed particles (C)obtained by firing particles of zinc oxide according to claim 1 at a temperature of from 300 to 1100°C in reducing atmosphere.

12. The calcined particles (b) In paragraph 11, which have on their surface at least one coating selected from the group comprising higher fatty acids, esters of phosphoric acid, esters of fatty acids and polyhydric alcohols, anionic surfactants and binders silane-based, titanate and aluminum.

13. Electroconductive resin composition (C)containing 100 weight. resin parts and from 200 to 400 weight. parts of calcined particles (b) In paragraph 11.



 

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EFFECT: polyorganosiloxanes lead to reduction of viscosity in rubber recycling and in case of necessity to improvement of mechanical properties of vulcanised rubber.

16 cl, 6 tbl

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. Claimed is dispersion of particles of titanium oxide with rutile structure, in which particles of titanium oxide with rutile structure have D50 in the range from 1 to 15 nm and D90 40 nm or less in distribution of particles in size in its determination by method of dynamic light dispersion; specific surface area in the range from 120 to 180 m2/g in determination by BET method; and degree of mass loss 5% or less in its determination by heating particles of titanium oxide with rutile structure from 105°C to 900°C. Said dispersion of titanium oxide particles is obtained by method, which includes the first stage, at which water solution of titanium tetrachloride is heated and hydrolysed to obtain suspension, which contains sedimented particles of titanium oxide with rutile structure; the second stage, at which suspension, obtained at the first stage, is filtered and washed with water; the third stage, at which suspension, obtained at the second stage, is subjected to hydrothermal reaction in presence of organic acid, the fourth stage, at which suspension, obtained at the third stage, is filtered and washed with water; the fifth stage, at which acid is added to suspension, obtained at fourth stage, and obtained mixture is subjected to wet dispersion, thus obtaining dispersion; and the sixth stage, at which excessive acid and water-soluble salts are removed from dispersion, obtained at the fifth stage.

EFFECT: invention makes it possible to increase stability of titanium oxide dispersions.

9 cl, 1 dwg, 2 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a coating composition containing an organic medium and a core/shell polymeric particle, said core having, when dry, at least one void and said shell having in form of polymerised links 18-50 wt % monomer, per weight of the shell, selected from a group comprising acrylonitrile, methacrylonitrile, acrylamide, methacrylamide and mixtures thereof, and 0.1-35 wt % polyethylenically unsaturated monomer, per weight of the shell, in form of polymerised links. The shell of the core/shell polymeric particle is characterised by a calculated shell/organic medium interaction parameter XPS>1.15. A method of providing opacity to coatings is also described.

EFFECT: providing effective levels of opacity of coatings.

4 cl, 18 ex, 11 tbl

FIELD: chemistry.

SUBSTANCE: method involves the following steps: selecting the target filling value L for the rubber composition; making a decision on n target intrinsic properties that are desirable for the mixture, where n is an integer greater than one; selecting a target value of the intrinsic property Xi, for each of the n target intrinsic properties; selecting a filling value Lj for each of the n fillers to be used to form the mixture; selecting n-1 fillers with known intrinsic properties xij, so that one undefined filler remains; providing for each of the n target intrinsic properties a mathematical link fi between the target filling value L, the target value of the intrinsic property Xi, corresponding to the value of the intrinsic property xij and the filling Li for each of the n fillers from said selection step; calculating corresponding values of intrinsic properties xij for the undefined filler from said selection step; and determining the identity of the undefined filler from said selection step by finding conformity of values of intrinsic properties xij from said calculation step and filler, having essentially the same values of intrinsic properties Xij as provided at said calculation step.

EFFECT: preparing a filler mixture for use in a rubber composition.

10 cl, 4 tbl, 3 dwg

FIELD: chemistry.

SUBSTANCE: method of producing polymer material, particularly polyethylene terephthalate (PET), which is filled with one filler, preferably calcium carbonate (CaCO3), which is sensitive to hydrolytic breakdown, is optionally hygroscopic, thermoplastic and is obtained by polycondensation, wherein under vacuum conditions while stirring constantly and at high temperature, a mixture of a still solid, optionally soft polymer material is filler is prepared first and wherein filler which is not subjected to pre-drying at the moment of adding is used, said filler having moisture content (H2O) higher than 500 ppm, particularly higher than 1000 ppm. Also disclosed is use of the filler to produce said filled polymer.

EFFECT: end products do not contain bubbles.

13 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a composition based on a thermoplastic elastomer for use in articles as a barrier layer for fluid media, suitable for use in industrial articles such as inner layers of car tyres and hoses and a method of producing said composition. The composition contains dispersed particles of at least a first elastomer and not more than 20 wt% dispersed particles of at least a second elastomer. The first elastomer includes a halogenated, isobutylene-containing elastomer and the second elastomer has glass transition point lower than -30°C and contains at least one functional group capable of reacting and grafting to a thermoplastic resin with a functional group selected from a group consisting of maleic anhydride, acyl lactam, which reacts with amine functional groups contained in polyamides. Particles of at least the first and at least the second elastomer are dispersed in a continuous phase of a thermoplastic resin having Young's modulus higher than 500 MPa and air permeability coefficient less than 60×10-12 cm3/cm2 s cm Nd (at 30°C). The composition or said at least first elastomer further contains at least one photochemical radiation-induced decomposition stabiliser. The composition is obtained by dynamic vulcanisation in a mixing extruder, a method of creating shearing of a polymer and elastomeric components at high temperature.

EFFECT: obtained composition remains thermoplastic, and articles made therefrom can be moulded by conventional moulding, extrusion or calendering.

20 cl, 2 dwg, 7 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to production of packaging materials (packaging walls and packaging articles) for food products and specifically relates to an oxygen-absorbing mixture used as an oxygen absorbent in food packaging, a composition containing a polymer resin and said oxygen-absorbing mixture and an article - packaging. The oxygen-absorbing mixture contains (I) an oxidisable metal component, (II) an electrolytic component selected from a group consisting of KCl and CaCl2, and (III) a non-electrolytic oxidising component. The mixture also contains a water-absorbing binding agent, e.g. zeolite, graphite, soot or clay. The composition used to make packaging articles contains a polymer resin, e.g. an olefin homo- or copolymer, polyamide (co)polymers, said oxygen-absorbing mixture and an optional additive selected from a group comprising UV absorbents, antioxidants and other light stabilisers. The packaging article is a film, a sheet or layered material.

EFFECT: invention increases oxygen absorption activity of packaging materials, eg films, the oxygen absorbent has excellent longevity.

14 cl, 2 tbl, 8 ex

FIELD: chemistry.

SUBSTANCE: film contains multilayered antioxygen barrier component, in which: i) active antioxygen barrier layer is located between two passive antioxygen barrier layers, or ii) passive antioxygen barrier layer is located between two active antioxygen barrier layers. Active layer contains oxygen-absorbing composition, which represents mixture of thermoplastic resin (A) with carbon-carbon double bonds mainly in main chain, salts of transition metal (B) and antioxygen barrier polymer (C). Passive layer contains material selected from group, including copolymer of ethylene and vinyl alcohol, polyvinyl alcohol and their copolymers and combinations. Multilayered antioxygen barrier component is located between sealing layer and stable to external impact layer. Invention also relates to package, containing food product and said film. Passive antioxygen barrier layers assist in preservation of antioxygen barrier properties of film after depletion of capacity to absorb oxygen of active barrier layer.

EFFECT: increased term of film service life.

9 cl, 6 dwg, 3 tbl, 3 ex

FIELD: process engineering.

SUBSTANCE: invention relates to abrasive particles and materials to be used for sand blast surface cleaning and finishing of the wide range of materials and surfaces. Formed abrasive particles containing alpha-alumina are shaped to irregular circle in cross-section made along lengthwise axis of said particles. Besides, they feature mean factor of roundness making about 15% and 0%. Invention covers also the abrasive material containing aforesaid particles.

EFFECT: higher quality and rate of band grinding.

15 cl, 3 tbl, 9 dwg, 3 ex

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