RU2687231C1 - Method of producing pigments - Google Patents

Abstract

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of composite materials, particularly pigments, which are widely used in production of paints, enamels, soils, as well as polymer, construction and rubber-technical materials. Method of producing pigments includes milling in vertical mill preferably to specific surface of 2,800–3,000 g/cm² and a fraction of not more than 60 mcm. Ground carrier is mixed with a color carrier and is ground under action of impact forces in rod mill at collision rate of 50–110 m/s. Remaining part of color carrier is added to obtained mixture and treated at collision rate of 70–230 m/s. Carrier used is preferably barium metaboride, calcium aluminosilicate, calcium borosilicate, calcium carbonate, barite or silicon dioxide and schungite.

EFFECT: invention provides improved technical properties of pigments, such as opacity, dispersibility and whiteness.

13 cl, 1 tbl, 5 ex

Description

The invention relates to the production of composite materials, in particular pigments that can be used in the manufacture of paints, enamels, soils, masterbatches of colored concrete, dry mixes, for dyeing plastics, as well as materials that can be used for vulcanization of rubbers based on most types rubbers as an agent for sulfur vulcanization.

A method of producing pigments by filler treatment in a centrifugal-elliptical mill "TsEM" or in the apparatus for grinding the planetary type when exposed to centrifugal force with an acceleration of 20-55 g for 1-4 minutes, followed by the introduction of organic or inorganic pigment and the joint processing of the mixture in the same apparatus (RF patent N 2077545, IPC SS09 1/60, SS 3/04, 1997).

The disadvantage of this method is the low opacity of the pigment obtained (44-55 g / m ² ), which causes a high consumption of pigment in its application. In addition, the processing of materials in mills "TsEM" leads to the formation of gray metallic dust (namol) from the intense mechanical wear of the grinding bodies and the inner wall of the working chamber, which gives the white pigment a dirty gray color. Mills "TsEM" have low actual performance (from 100 to 350 kg / h), are not equipped with a classification system and return for recycling of large particles / aggregates of the outgoing product, as well as in these complexes there is no possibility of removing microfraction (0-5 microns) from the working chamber / from the zone of destruction, which leads to dissipation of the input energy and the formation of secondary, small-dense aggregates and, as a result, reduces the hiding power and whiteness of the final product. The design features of these mills lead to frequent non-scheduled stops (up to 6-10 per shift) due to the constant "clogging" of the working chamber of the reaction product. Subsequent operations - disassembly, cleaning, assembly takes 20-30 minutes. In addition, extremely rapid wear of moving and rubbing parts and assemblies (bearing units, eccentric shaft, rocking axles, working chambers, flexible inserts of the transition from the screw feeder to the inlet of the working chamber) is noted.

A method of obtaining pigments by grinding the filler with a part of the dye, taken in an amount of not more than 5 wt. % of the total amount of dye in a vibrocentrifugal mill with ball loading of 65-70%, followed by mixing the resulting mixture with the rest of the specified dye and processing it in a vibratory centrifugal mill with ball loading of 50-55% (RF Patent No. 21114885, IPC SVB 67/04, C09C 3/06, 1998).

Achieved an increase in the dispersion of the pigment, improved paint-technical characteristics, namely, opacity, dispersibility, coloring ability and color characteristics.

The closest in execution is a method for producing pigments, which consists in the fact that the mineral is mechanically activated with grinding under the influence of centrifugal force (in CEM mills). Then it is mixed with the color carrier and subjected to grinding in the first mixer of a discrete-continuous forced action under the action of centrifugal force. The resulting mixture is transferred to the second mixer, add the remaining part of the color carrier and also crushed under the action of centrifugal force (RF patent №2205849, IPC C09C 1/60, C09C 3/04, 2003).

A pigment is obtained which has an insufficiently high opacity (using titanium dioxide from 80 to 40 g / m ² ) and dispersibility (from 30 to 20 μm), as well as whiteness (95%).

The technical result is an increase in the technical performance of pigments, such as opacity, dispersibility and whiteness.

The technical result is achieved by the fact that the carrier is subjected to grinding in a vertical mill, then mixed with a color carrier and crushed under the action of impact forces in a rod mill with a collision speed of 50-110 m / s, the rest of the color carrier is added to the mixture at the same time or in several stages and processed with a speed of collisions of 70-230 m / s.

Adding color carrier is carried out mainly in different mills.

As a carrier, for example, barium metaboride or calcium aluminosilicate or calcium borosilicate or calcium carbonate or barite or silica or schungite can be used.

For example, titanium dioxide of the rutile form TiO ₂ or zinc white of the BTsOM and BTs-1 grades according to GOST 202-84, BTsV 1 and BTsV 2 of the grades A and B according to TU 2321 can be used as color carrier. -001-50992567-2003 or lead white PbCO ₃ . or carbon black or phthalocyanine blue or phthalocyanine green.

The grinding of the carrier in a vertical mill, where the material is crushed under the rollers (compaction, compression, crushing, shear), is preferably carried out up to a specific surface area of 2800-3000 g / cm ² , which corresponds to a fraction of not more than 60 microns.

A material with a whiteness of at least 60% is preferably used as a carrier.

The ratio of media and the total amount of color carrier is mainly 15-85 wt. hours and 85-15 wt. hours, respectively.

Upon initial introduction into the core mill of the color carrier, a modifier may additionally be added in the amount of 1-7 wt. including the total number of media and color carrier.

As a modifier, inhibitors of photochemical processes can be used to increase photostability and light resistance, additives to neutralize electrostatic charges- (decrease the level of electrical charges of positive polarity), damage intensifiers, as well as modifiers to prevent agglomeration, improve flowability, hydrophobicity or hydrophilicity, prevent cracking polymer matrix (for example, siloxanes, salts of fatty acids, compounds of aluminum oxide and silicon, many ohm alcohols).

The ratio of wt. h. tsvetokositelya with the initial introduction and subsequent to the advantage of not less than 0.3.

The ratio of wt. including color carrier in subsequent injections does not have advantages.

The resulting mixture after the rod mills can be further processed in a jet mill, where the speed of oncoming flows reaches 800-1000 m / s.

The resulting mixture after the rod mills can be further processed by pressing under a pressure of 8-20 N / mm ² in a roller press.

The particle size after final grinding is preferably 0.5-3 microns.

The difference of the proposed method from the prototype is to use for grinding vertical mills and rod, and it is also possible to use a jet mill and a press.

Below are examples of the invention.

Example 1. PC Pigment Product

Stage 1. Stage preparation media

Quartz sand fraction of 2-5 mm with a whiteness of 90% serves on a rotating table of a vertical mill. The material moves along the surface of the table and falls under the action of the spring-loaded rolls, under them a pre-compaction, compression, crush, shear occurs. The specific pressure in the working area is 5-15 N / mm ² . The treated product is carried away by the air flow to the separator. The separator eliminates the chemically neutral, large fraction of 60-300 microns and returns it to recycling. The fraction of quartz sand (30-60 microns) is sent to the hopper drive quartz flour.

Stage 2. The stage of homogenization and dispersion of raw materials in successively installed rod assemblies with rotors of different designs and providing different impact speeds.

Raw mix: pre-prepared carrier - quartz flour 30-60 microns in a volume of 58 wt. h, tsvetonitel - titanium dioxide of rutile form in a volume of 15 wt. h, the modifier is aluminum hydroxide in a volume of 2 wt. hours to improve the resistance of the pigment to UV irradiation and reduce photochemical activity.

Raw mix is fed into the working chamber of the rod mill №1. This device implements a powerful free-hit mode, the impact velocity reaches 50-70 m / s.

The processed product from the working chamber of the rod mill No. 1 is fed to the mixer-accumulator of the rod mill No. 2, 10 wt. including titanium dioxide rutile form. In the rod mill No. 2, the following consecutive strikes are implemented, the impact velocity is 70-110 m / s.

Next, the intermediate product enters the mixer-accumulator of the rod mill No. 3, 15 wt. including titanium dioxide. From the mixer-accumulator, the reaction mass is fed into the working chamber of the core apparatus No. 3, where the impact velocity reaches a maximum value of 200 m / s.

Sequential mechanical action of core aggregates accelerates the processes of phase formation, and compounds and solid solutions appear in the deformed samples — formation of the final product.

Stage 3

From the receiving hopper of the accumulator of the jet unit, the reaction mixture is fed into the working chamber of the counter-current jet mill. In the working chamber, the process of deformation-molecular mixing occurs due to the collision of counter-flows of material particles. The speed of oncoming flows is 1000 m / s. The micronization process lasts until particles of 0.5–3 µm in size leave the microfraction exit chamber through the built-in air-dynamic classifying rotor.

Stage 4

Next, the reaction mass is fed to the raw material storage interval space roller press. Three rolls rotating at different speeds crush / deform / disaggregate the solid solution of the reaction mass. Specific pressure in the working area 10 N / mm ²

Then the product PC-pigment is fed into the receiving hopper - the drive of the finished product. The obtained product investigated the technical indicators, which are shown in table 1.

Example 2. Products BC-OK and BC-OC.

Stage 1.

Analogously to example 1, the carrier barite fraction of 2-5 mm with a whiteness of 60% is fed to a rotating table of a vertical mill. The specific pressure in the working area is 5-15 N / mm ² . The fraction of the carrier 30-40 microns is sent to the hopper drive microbarite.

Stage 2

Raw mix: pre-prepared carrier barite - 30-40 microns in a volume of 60 wt. h, tsvetonitel - zinc oxide in a volume of 15 wt. h, modifier-stearic acid to impart hydrophilicity, as well as to reduce the stock of surface energy in a volume of 2 wt. h

Analogously to example 1, the raw material mixture is fed into the working chamber of the rod mill, where the impact velocity reaches 60 m / s.

The processed product from the working chamber of this rod mill is fed into the rod mill, where the impact velocity reaches 150 m / s, and 12 wt. including zinc oxide.

Next, the intermediate product enters the rod mill, where the impact velocity reaches a maximum value of 180 m / s, and 11 wt. including zinc oxide.

Stage 3

From the receiving hopper of the accumulator of the jet unit, the reaction mixture is fed into the working chamber of the counter-current jet mill. The speed of oncoming flows 800 m / s. The micronization process lasts until particles of 0.5-3 microns in size leave the microfraction exit chamber.

Stage 4

Next, the reaction mass is fed to the roller press. The specific pressure in the working zone is 8 N / mm ² .

Then the finished product is fed into the receiving bunker - the drive of the finished product. The obtained product investigated the technical indicators, which are shown in table 1.

Example 3 PC Pigment Product

Stage 1.

Analogously to example 1, a carrier of calcite fraction 2-5 mm with whiteness of 95% is fed into a vertical mill. The specific pressure in the working area is 5-15 N / mm ² . The fraction of calcite 30-40 microns is sent to the hopper microcalcite accumulator.

Stage 2.

Raw mix: pre-prepared carrier - microcalcite 30-40 microns in a volume of 15 wt. h, tsvetonitel - rutile titanium dioxide in a volume of 35 wt. h, modifier aluminum stearate to improve wettability in a volume of 1 wt. h

Analogously to example 1, the raw meal is fed into the working chamber of the rod mill, where the impact velocity reaches 80 m / s.

The processed product from the working chamber of this rod mill is fed to the rod mill, where the impact velocity reaches 120 m / s, and 15 wt. h titanium dioxide rutile form.

Next, the intermediate product enters the rod mill, where the impact velocity reaches 150 m / s, and 14 wt. including titanium dioxide rutile form.

Next, the intermediate product enters the rod mill, where the impact velocity reaches 200 m / s, and 20 wt. including titanium dioxide rutile form.

Stage 3

Next, the product is fed into the working chamber of the countercurrent jet mill, where the speed of oncoming flows reaches 900 m / s. The micronization process lasts as long as the particles are 0.5-3 microns in size. Do not leave the microfraction exit chamber.

Then the finished product is fed into the receiving hopper - the drive of the finished product. The obtained product investigated the technical indicators, which are shown in table 1.

Similarly, the example injected into the first rod mill 29 wt. including color carrier and 7 wt. h modifier.

Example 4

Stage 1.

Analogously to example 1, a carrier of calcite fraction of 5-7 mm, 96% whiteness is fed into a vertical mill. The specific pressure in the working area is 10-15 N / mm ² . The fraction of calcite 20-30 microns is sent to the hopper microcalcite accumulator.

Stage 2.

Raw mix, pre-prepared carrier - microcalcite 20-30 microns in a volume of 62 wt. h, tsvetonitel - titanium dioxide of rutile form in a volume of 15 wt. h, the modifier is A1 hydroxide to improve the resistance of the pigment to UV irradiation and reduce photochemical activity in a volume of 3 wt. h

Analogously to example 1, the raw material mixture is fed into the working chamber of the rod mill, where the impact velocity reaches 110 m / s.

The processed product from the working chamber of this rod mill is fed into the rod mill, where the impact velocity reaches 140 m / s, and 10 wt. including titanium dioxide rutile form.

Next, the intermediate product enters the rod mill, where the impact velocity reaches 180 m / s, and 10 wt. including titanium dioxide rutile form.

Next, the intermediate product enters the rod mill, where the impact velocity reaches 230 m / s.

The resulting PC-pigment is fed into the receiving hopper - the drive of the finished product.

The obtained product investigated the technical indicators, which are shown in table 1.

Example 5

Stage 1.

Analogously to example 1, a carrier of quartz sand of a fraction of 2-5 mm with a whiteness of 90% is fed to a vertical mill. The specific pressure in the working area is 5-15 N / mm ² . The fraction of quartz sand of 20-40 microns is sent to the storage hopper of quartz flour.

Stage 2.

Raw mix: pre-prepared carrier quartz flour 20-40 microns in a volume of 50 wt. h, tsvetonitel - titanium dioxide rutile form in a volume of 25 wt. h, the modifier is silicon hydroxide to improve the resistance of the pigment to UV irradiation and reduce photochemical activity in a volume of 2 wt. h

Analogously to example 1, the raw material mixture is fed into the working chamber of the rod mill, where the impact velocity reaches 100 m / s.

The processed product from the working chamber of this rod mill is fed into the rod mill, where the impact velocity reaches 160 m / s, and 23 wt. including titanium dioxide rutile form.

Stage 3

Next, the reaction mass is fed to the roller press. Specific pressure in the working area of 20 N / mm ² .

Then the finished product is fed into the receiving hopper - the drive of the finished product. The obtained product investigated the technical indicators, which are shown in table 1.

Analogously to the example, 85 wt. including media, 10 wt. including color carrier - rutile titanium dioxide in the first rod mill without the addition of modifier, 5 wt. h in the second rod mill. Get similar results.

Similarly, in the examples, barium metaboride, calcium aluminosilicate, calcium borosilicate, silica, schungite are used as carriers; as a color carrier lead white PbCO ₃ , carbon black, phthalocyanine blue, phthalocyanine green; as a modifier siloxanes, polyhydric alcohols.

Analogously to the example, 73 wt. including media, 20 wt. including color carrier - rutile titanium dioxide in the first rod mill without the addition of modifier, 7 wt. h in the second rod mill. Get similar results.

As you can see, the proposed method allows to obtain pigments with technical indicators at the level of expensive pigments of titanium dioxide and zinc oxide, and superior indicators, whiteness, dispersibility and in some cases, the rates of opacity of the closest pigments.

Claims (13)

1. A method of producing pigments, characterized in that the carrier is subjected to grinding in a vertical mill, then mixed with a color carrier of organic or inorganic origin, crushed under the action of impact forces in a rod mill with a speed of collisions of 50-110 m / s, to the resulting mixture add the remaining part tsvetonositelya and process with a speed of collisions 70-230 m / s. 2. The method according to claim 1, characterized in that barium metaboride, calcium aluminosilicate, calcium borosilicate, calcium carbonate, or barite, or silica, or shungite are used as a carrier. 3. The method according to claim 1, characterized in that titanium dioxide of rutile form TiO ₂ , or zinc white ZnO, or lead white PbCO ₃ , or carbon black, or phthalocyanine blue, or phthalocyanine green is used as the color carrier. 4. The method according to claim 1, characterized in that the grinding of the carrier in a vertical mill is preferably carried out to a specific surface area of 2800-3000 g / cm ² , which corresponds to a fraction of not more than 60 microns. 5. The method according to claim 1, characterized in that a material with a brightness of at least 60% is used as a carrier. 6. The method according to claim 1, characterized in that the ratio of the carrier and the total amount of the color carrier is preferably 15-85 wt. hours and 85-15 wt. hours, respectively. 7. The method according to claim 1, characterized in that upon initial introduction of a color carrier in the rod mill, an additional modifier is added in an amount of 1-7 wt. including the total number of media and color carrier. 8. The method according to claim 7, characterized in that inhibitors of photochemical processes are used as a modifier to increase photostability and light resistance, additives to reduce the level of electrical charges of positive polarity, damage intensifiers, as well as modifiers to prevent agglomeration, improve flow, hydrophobicity or hydrophilicity modifiers , prevent cracking of the polymer matrix, for example siloxanes, salts of fatty acids, compounds of aluminum oxide and silicon, polyhydric alcohols. 9. The method according to claim 1, characterized in that the remainder of the color carrier is added in a ratio of not less than 0.3 wt. hours to the original amount. 10. The method according to claim 1, characterized in that the remainder of the color carrier is introduced simultaneously or in several stages. 11. The method according to claim 1, characterized in that the mixture obtained after rod mills is further processed in a jet mill, where the speed of oncoming flows reaches 800-1000 m / s. 12. The method according to claim 1, characterized in that the resulting mixture after the rod mills is further processed by pressing under a pressure of 8-20 N / mm ² in a roller press. 13. The method according to claim 1, characterized in that the particle size after final grinding is 0.5-3 microns.