Carbon black, composition containing carbon black

This application is a continuation in part of US application N 07/935794, filed August 27, 1992

The present invention relates to a new class of carbon sazham which are suitable for various applications, and they may be used in particular in plastics and rubber.

BACKGROUND ART Carbon blacks can be used as pigments, fillers, reinforcing agents and in various other applications. It is widely used to prepare the compositions of the rubber and plastics, where it is required to achieve the optimum combination of processing properties of the material and physical properties of finished articles.

Carbon black is usually characterized on the basis of its properties, including without limitation its surface area, surface chemistry, aggregate sizes and particle.

The properties of carbon black determined analytically by known in the art testing, including the determination of iodine adsorption number (I2No), the degree of absorption of dibutyl phthalate (DBP), the ink capacity (TINT - hue, tone), the average diameter of Stokes (Dst), diameter according to Stokes at the peak (Dmode) ratio and M-Ratio, which is defined as the average diameter (Median Stokes Diameter) according to Stokes divided by Stokes diameter at the point on the distribution curve peak Stokes diameter (M-Ratio = Dst / Dmode).

Among the documents relating to the prior art solutions, you can specify several patents. These include U.S. Patents NN 4366139, 4221772, 3799788, 3787562, USSR Patent N 1279991, Canadian Patent 455 504 N, N Japanese Patent 61-047759, British patent N 1,022,988 and Japanese Patent 61-283635 N. However, none of these patents disclose the carbon black products produced in accordance with the present invention. Furthermore, none of these patents describe applications in which carbon black is used in accordance with the present invention.

SUMMARY OF THE INVENTION Applicants have discovered nine new classes of carbon blacks, intended primarily for inclusion in compositions of rubber and plastic where the importance of such technological and physical material properties such as mixing energy, viscosity, cure speed, shrinkage during extrusion, tensile strength , fatigue strength, compression set, hardness, resistivity and surface appearance. It has been found that these carbon blacks have a unique combination of properties that make them particularly suitable for use in extrusion, molded articles, hoses and belts.

The first class of carbon blacks has an I2No iodine value = 17-23 mg / g (milligrams I2 per gram carbon black) and a DBP dibutylphthalate adsorption rate = 115-150 cc / 100g (cubic centimeters of dibutyl phthalate per 100 grams carbon black). Preferably this class of carbon blacks is characterized by having an iodine number (I2No), equal to about 20 mg / g.

The second class of carbon black has I2No = 10-19 mg / g and DBP = 70-95 cubic meters. cm / 100g

Third grade carbon black has I2No = 12-20 mg / g and DBP = 34-65 cubic meters. cm / 100 g Preferably this class of carbon blacks is characterized by having I2No = 14-18 mg / g and a DBP = 36-55 cc / 100 g, and more preferably a DBP = 36-42 cc / 100 g or 45-55 cc / 100 g

A fourth class of carbon blacks has an I2No = 28-43 mg / g and a DBP = 28-47 cc / 100 g Preferably this class of carbon blacks is characterized by having I2No = 30-42 mg / g.

Fifth grade carbon black has I2No = 8-32 mg / g, DBP = 28-150 cubic meters. cm / 100 g, and M - the ratio of 1,25-2,00.

Sixth grade carbon black has I2No = 33-70 mg / g, DBP = 28-60 cubic meters. cm / 100 g, and M - the ratio of 1,25-2,00.

Seventh grade carbon black has I2No = 42-50 mg / g, DBP = 61-105 cubic meters. cm / 100 g, and M - the ratio of 1,25-2,00.

Eighth grade carbon black has I2No = 51-62 mg / g, DBP = 61-125 cubic meters. cm / 100 g, and M - the ratio of 1,25-2,00.

Ninth grade carbon black has I2No = 62-70 mg / g, DBP = 61-105 cubic meters. cm / 100 g, and M - the ratio of 1,25-2,00.

There were also discovered new classes of compositions of rubber and plastics containing carbon blacks.

Carbon black in accordance with the present invention can be prepared in a reactor for the production of furnace carbon black having a combustion zone, a transition zone and a reaction zone. The feedstock for the production of carbon black introduced into the stream of hot combustion gases. The resultant mixture of hot combustion gases and feedstock passes into the reaction zone. Pyrolysis of the feedstock to produce carbon black is stopped by quenching the mixture after the formation of the carbon black in accordance with the present invention. Preferably pyrolysis is stopped by injecting a quenching fluid. A process for preparing the new carbon blacks of the present invention will be described in more detail.

Rubber and plastics, which can be applied a new class of carbon blacks in accordance with the present invention include natural and synthetic rubbers and plastics. In general, for every 100 parts by weight of rubber or plastic may be used from about 10 to 300 wt. parts of the carbon black.

Among the rubbers or plastics suitable for use in accordance with the present invention, mention may be natural, synthetic rubber and their derivatives such as chlorinated rubber; copolymers containing from about 10 to 70 wt.% styrene and about 90-30 wt.% of butadiene such as copolymer of 19 parts styrene and 81 parts butadiene, containing 30 parts styrene and 70 parts butadiene, a copolymer of - 43 parts of styrene and 57 parts butadiene and a copolymer of - 50 parts styrene and 50 parts butadiene; polymers and copolymers of dienes with conjugated double bonds such as polybutadiene, polyisoprene, polychloroprene, and the like, and copolymers of such dienes with conjugated double bonds with a copolymerizable monomer containing ethylenic group, for example, styrene, methylstyrene, chlorostyrene, acrylonitrile, 2-vinyl pyridine, 5-methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine, 2-methyl-5-vinylpyridine, alkyl-substituted acrylates, vinyl ketone, metilizopropenilovy ketone, methyl vinyl ester, alpha-methylene carboxylic acids and esters and amides such as amides of acrylic acid and dialkylacrylic acid; and for use in accordance with the invention are also suitable copolymers of ethylene and other high alpha olefins such as propylene, butene-1 and peneten-1; especially preferred are ethylene-propylene copolymers wherein the ethylene content ranges from 20 to 90 wt.%, and the ethylene-propylene polymers which additionally contain a third monomer such as dicyclopentadiene, 1,4-hexadiene and methylene norbornene. Also preferred polymeric compositions are olefins such as polypropylene and polyethylene.

An advantage of the carbon blacks of the present invention is that the carbon black suitable for its introduction into a natural rubbers, synthetic rubbers, plastics or blends thereof for industrial applications, particularly important when the material processing properties and product performance.

A further advantage of the carbon blacks of the present invented iem is that the carbon black is determined in accordance with the present invention would replace the mixture of carbon black in applications that currently require the use of blends of carbon blacks to achieve desired performance characteristics.

Other advantages of the present invention will become apparent from the following more detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 - sectional view of a portion of one type of reactor for the production of furnace carbon blacks that can be used to produce the carbon blacks of the present invention.

FIG. 2 - a histogram of the weight fraction of the aggregates of the carbon black samples according to the Stokes diameter according to a given sample.

DETAILED DESCRIPTION OF THE INVENTION The analytical properties of each of the nine classes of carbon blacks of the present invention are listed in Table 1.

Carbon black in accordance with the present invention can be prepared in modular, so-called "stepwise" reactor for producing carbon black. A sectional view of a typical modular reactor that can be used for the production of carbon black according to the present invention is shown in FIG. 1. Other details of a typical modular reactor for the production of carbon black can be found, for example, in U.S. Patent N 3,922,335, which are herein incorporated by reference.

A reactor for producing carbon black, which is particularly well suited for producing carbon black in accordance with the present invention is described in US application serial number 07/818943, filed January 10, 1992 the present applicant and incorporated herein by reference above.

The carbon blacks of the Examples described herein was prepared by the method disclosed in US application '943.

Application '943 discloses a process for producing carbon black, whereby the reaction zone of a multistage reactor auxiliary hydrocarbon is added, with the primary and overall combustion in the reaction is adjusted so that the SSI of the process is less than zero. SSI of the process may be determined by the following equations: where ;; Δ (DVR) mf- change in the value of the adsorption of dibutyl phthalate (DBPA) of the carbon black due to changes in the flow rate of raw materials, consumption of raw materials, while all other operating conditions constant; Δ (iodine number) ah - change in the iodine number of carbon black due to changes in consumption of raw materials; all other process operating conditions constant; Δ (DBP) ah - change in DBPA carbon black due to changes in the flow of additional carbon, while all other process operating conditions remain constant; and Δ (iodine number) ah - change in iodine adsorption of carbon black due to changes in the flow of additional hydrocarbon, while all other process operating conditions remain constant.

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"Auxiliary hydrocarbon" comprises hydrogen or any hydrocarbon having a molar hydrogen-to-carbon ratio greater than the molar ratio of hydrogen to carbon in the feedstock.

As shown in FIG. 1, the carbon blacks of the present invention can be obtained in the reactor 2 for the production of furnace carbon black having a combustion zone 10, which includes a zone of converging diameter 11, transition zone 12, entry section 18, and reaction zone 19. The diameter of the combustion zone 10 to the point where the zone of converging diameter begins 11, designated as D-1; the diameter of zone 12 - as D-2; the diameters of the stepped entry section 18 - as the D4, D5, D6, D7, and the diameter of zone 19 - as D-3. The length of the combustion zone 10, up to the point where the zone of converging diameter begins 11, designated as L-1; length of the zone of converging diameter - L-2, the length of the transition zone - L-3 and the length of the steps in the reactor entry section 18, indicated as L4, L5, L6 and L7.

For the carbon black in the combustion zone 10 the hot flue gases generated upon contact of a liquid or gaseous fuel with a stream corresponding oxidant such as air, oxygen, mixtures of air and oxygen or the like Among the fuels suitable for contacting the oxidant stream in combustion zone 10 for generating hot flue gas may be any combustible gas, vapor or liquid streams such as natural gas, hydrogen, carbon monoxide, methane, acetylene, alcohol, or kerosene. However, generally preferred to use fuels having a high content of carbon-containing components and in particular hydrocarbons. The ratio of air to natural gas used for producing the carbon blacks of the present invention may preferably be from about 10: 1 to about 100: 1. To facilitate the formation of hot flue gases, the oxidant stream may be preheated.

The stream of hot flue gas passes downstream from zones 10 and 11 into zones 12, 18 and 19. The direction of flow of hot combustion gases is indicated by an arrow in FIG. Feedstocks 30 for the production of carbon black is introduced at point 32 (located in zone 12), or at the point 70 (located in zone 11). Suitable materials for use herein as hydrocarbon feedstocks for the production of carbon black, which are easily volatilized at the reaction conditions, are unsaturated hydrocarbons such as acetylene, olefins such as ethylene, propylene, butylene; aromatic hydrocarbons such as benzene, toluene and xylene; certain saturated hydrocarbons and other hydrocarbons such as kerosenes, naphthalenes, terpenes, ethylene tar, aromatic cyclic hydrocarbons, etc.

The distance from the end of the zone of converging diameter 11 to point 32 is designated as P-1. Typically, feedstock 30 for the production of carbon black is introduced in the form of a plurality of streams which pass in the inner zone of flow of hot combustion gases to provide a high degree of mixing and shearing the feedstock starting materials by the hot flue gases to accelerate complete decomposition and conversion of feedstock to carbon black.

Auxiliary hydrocarbon is introduced at point 70 through probe 72 or channel 75 for the auxiliary hydrocarbon is in the walls which form the boundaries of zone 12 of the formation of carbon black or through channels 76 for the auxiliary hydrocarbon, formed in the walls which form the boundaries of zones 18 and / or 19 in the manufacturing process carbon black. Additional hydrocarbon can be administered anywhere between a point immediately after the initial combustion reaction of fuel in the first stage, and the point just before the completion of the formation of carbon black provided that unreacted auxiliary hydrocarbon enters ultimately into the reaction zone.

The distance from point 32 to point 70 is designated as H-1.

In the examples described herein auxiliary hydrocarbon was introduced through three or four holes in one axial plane with the feed stream for the production of carbon black. The holes are arranged alternately - one for the feedstock for other auxiliary hydrocarbon, and they are uniformly spaced on the outer periphery of section 12. However, as can be seen, this is just an example which does not limit the options for adding auxiliary hydrocarbon.

A mixture of starting raw materials for the production of carbon black and the hot flue gases pass downstream through zone 12 into zone 18 and then into zone 19. The cooling collector 60 installed at point 62, to enter the coolant 50, as which may be water used to stop chemical reaction when carbon black is formed. Any known method can determine the point 62 to select the cooling collector to stop pyrolysis. One method of determining the position of the coolant collection to stop pyrolysis - is defining a point at which achieves acceptable levels of toluene for extraction of carbon black. The level can be measured by the toluene extraction test D1618-82 ASTM "extractables carbon black - change the color of toluene." Q is the distance from the beginning of zone 18 to quench point 32, which distance will vary depending on the position of the coolant collection 60.

After chilling the mixture of hot combustion gases and feedstock for the production of carbon black the cooled gases pass downstream into any conventional cooling and separating means thus recovered carbon black. Branch of soot from the gas flow is easily accomplished by conventional means such as precipitating agent, cyclone separator or bag filter. For this separation may be followed by granulation using, for example, a device for the wet granulation method.

For evaluating the analytical and physical properties of the carbon blacks of the present invention apply the following test methods.

The iodine adsorption number of carbon black (I2No) was determined by testing D1510 ASTM. Coloring power (Tint) of the carbon black determined according to ASTM test method D3265-85a. The number of DBP (dibutyl phthalate value) of the carbon blacks was determined according to the method ASTM D3493-86. The degree of absorption of cetyl-ammonium trimetilbromida (CTAB) carbon black determined according to test method ASTM D3766-85.

Diameter (Dmode) the diameter (Sst) carbon black were determined from a histogram of the weight fraction of carbon black, depending on the diameter, expressed by Stokes, carbon black aggregates, as shown in FIG. 2. The data used to compile the histogram are obtained with the disk centrifuge, for example from Joyce Loebl Co., Ltd s End Uier Tyne, UK. The following method is an improvement of the method described in the manual DSG 4.008 Operating disk centrifuge firm Joyce Loebl published February 1, 1985, which is listed here for reference and which is used in determining the data.

The method consists of the following 10 mg (milligrams) of a carbon black sample are weighed in a weighing vessel, then added to 50 cc. cm. solution of 10% absolute ethanol and 90% distilled water which is added 0.05% of a surfactant NONIDET P-40 (trade mark for a surfactant sold by Shell Chemical Co.). The resulting suspension is dispersed by means of ultrasonic energy for 15 minutes using an ultrasound device models Sonifier W385, manufactured and sold by Heath System Ultrazoniks Inc., Farmingdale, New York.

Prior to the disk centrifuge are administered following data into the computer which records the data disk centrifuge: 1. The specific gravity of carbon black, expressed as 1.86 g / cc; 2. The volume of the solution of the carbon black dispersed in a solution of water and ethanol, the amount of which in this case is 0.5 cc; 3. The volume of liquid to the centrifugal molding, which in this instance is 10 cc of water; 4. The viscosity of the liquid to the centrifugal molding 0,933 centipoise at a temperature of 23oC; 5. The density of the liquid to the centrifugal molding 0.9975 g / cc. cm at a temperature of 23oC; 6. The disk speed of 8000 rev / min; 7. The data sampling interval, which in this instance is 1 second.

The disk centrifuge is operated at 8000 rev / min, the effect stroboscope. In the rotating disc centrifuge injected 10 cc distilled water as the medium for the molding. Turbidity level is set to 0; as a buffer liquid introduced 1 cc solution of 10% absolute ethanol and 90% distilled water. Then click on the button raising and lowering speed of the disc centrifuge to create a smooth concentration gradient between the liquid and for forming the buffer liquid and the gradient is controlled visually.

When the gradient becomes smooth such that there is no distinguishable boundary between the two fluids, 0.5 cc is administered dispersed carbon black in aqueous ethanol solution to a disk centrifuge and immediately begin collecting data. If there is over, the work stops. The disc is rotated for 20 minutes after entering the dispersed carbon black in aqueous ethanol solution. After rotation for 20 minutes, the disk is stopped, the temperature of the measured fluid for molding and the average temperature of the liquid molding operation first measured, and the temperature of the fluid measured at the end of the work is introduced into the computer which records the data disk centrifuge. The data are analyzed according to the standard Stokes equation and are presented using the following definitions: Carbon black aggregate - a discrete rigid colloidal entity that is the smallest dispersible unit block, wherein the unit consists of a highly coalesced particles; diameter Stokes - is the diameter of a sphere which is deposited in a viscous medium in a centrifugal or gravitational field according to the Stokes equation, non-spherical object, such as carbon black aggregate, may also be represented in the value of the diameter according to the Stokes equation, assuming that it behaves as a smooth rigid sphere of the same density, and rate of deposition - as an object, ordinary units are expressed as diameter in nanometers; mode (Dmode for reporting purposes) - according to Stokes diameter at the point of the peak (in this case, point A in FIG. 2) on the distribution curve for Stokes diameter.

Mean Stokes diameter (Dst - for reporting purposes) - the point on the distribution curve of Stokes diameter where 50% by weight of sample - large or small. Thus it represents the average value of the determination.

The tensile modulus and elongation EPDM compositions were measured by the method ASTM D412-87.

Hardness Shore A EPDM compositions was determined by ASTM 2240-86-D.

These rebound EPDM compositions were determined in accordance with ASTM method D1054, using the device model 5109, manufactured by Zwick s America, Inc., PO Box 997, East Windsor, Connecticut 06 088, which is designed to test the elastic rebound. For device attached instructions for determining the value of rebound.

Compression set EPDM compositions was determined by ASTM D395, according to which the material was tested at a temperature of 150oF (65,56oC) for 70 hours.

Shrinkage extrusion EPDM compositions was determined according to the method ASTM D-3674. Extrusion shrinkage was measured on a Brabender extruder at a temperature of 100oC and a speed of 50 rev / min, using an extrusion die 5 mm in diameter.

The viscosity of the EPDM compositions was determined by ASTM D-1646 using a Monsanto capillary rheometer MRI maintained at a temperature of 100C, with a head having a length to diameter ratio L / D '= 16 and D = 0.0787 mm. Speed ​​was to move in! 10-150 l / sec.

The mixing energy represents the total amount of energy inherent in the composition is determined by integration of the torque curve during mixing during the mixing cycle to be described.

Cure characteristics EPDM compositions were measured using a Monsanto MDR device for determining the characteristics of curing which was maintained at a temperature of 160C. The time to reach 90% of the vulcanization reaction (t'90), the overall change in torque during the cure reaction (ΔL) and cure rate index (CR1; CR1 = 1 / (t'90-ts1) • 100 where ts1 -time when the torque level is 1 unit above minimum torque (ts1 is also determined as a scorch time) are for example EPDM compositions. The tests were conducted in accordance with the instructions attached to the instrument Monsanto MDR test to vulcanization.

The resistivity of the compositions was measured on samples in the form of two plates 2 inches wide x 6 inches long x 0.085 inch thick (50.8 mm x 152.4 mm x 21.8 mm). Painted plates at both ends of a thickness of about half an inch (12.7 mm) with silver paint. The sample is brought to the required conditions to obtain a stable indication by thermal cycling from room temperature to 100oC, and back to room temperature, followed by aging at 90oC for 24 hours. Stable resistance was measured at the end of the aging cycle, and once again after the sample is cooled to room temperature.

The effectiveness and advantages of the present invention will be further illustrated by the following examples.

Examples 1-8.

Examples of the carbon black grade in accordance with the present invention were obtained in the above described reactor, which is shown in FIG. 1 using the reactor conditions and geometry set forth in Table 3. The fuel used in the combustion reaction of natural gas. As an auxiliary hydrocarbon used was also natural gas. Liquid feedstock had the properties indicated in Table 2.

The geometry and reactor conditions listed in Table 3 below.

HC - hydrocarbon.

Soot obtained in Examples 1-8 were then analyzed according to the methods described herein. Analytic properties of carbon black are listed in Table 4.

This carbon blacks and four control carbon black sample was used in the following examples. Applicable four (A-D) control samples had carbon black analytical properties shown in Table 5.

Example 9.

Carbon black in accordance with the present invention obtained in Examples 1-8 were added in the composition of EPDM (etilenpropilendien-polymethylene) compositions and compared to EPDM, includes four types of control carbon black. EPDM compositions were prepared using each sample of the carbon black in an amount of 200 parts by weight of EPDM in the composition, indicated in Table 6.

EPDM-EXXON VIST-AL-ON® 5600- product of Exxon Corporation, Houston, Texas, Sunpar 2280 - brand oil manufactured and sold by San Oil Company, TMTDS - tetramethylthiuram, Butyl Zimate - brand product - tsinkdibutilditiokarbamat produced and supplied by RT Vanderbilt Co., Methyl Zimate - brand product - tsinkdimetilditiokarbamat- manufactured and supplied by R.T.Vanderbilt Co., Sulfasan R - trade name 4,4'-dithiodimorpholine manufactured and sold by Monsanto Co., St. Louis, MO.

EPDM compositions were prepared as follows.

Enabled model Banbury BR mixer and maintained at a temperature of 45oC and a rotor speed of 77 rev / min. EPDM was added to the mixer and mixed for approximately 30 seconds. The EPDM was added Sunpar 2280 oil, zinc oxide and stearic acid, and mixed for approximately 2 additional minutes. The mixture was added to the carbon black, the temperature in the mixing chamber reduced and maintained below about 135C. A mixture of EPDM, carbon black containing, mixed for approximately 4 1/2 minutes and then added to a mixture of vulcanizing agents TMIDS, Butyl Zimate (tsinkdibutilditiokarbamat), Methyl Zimate (tsinkdimetilditiokarbamat), sulfur, and 4-dithiodimorpholine (Sulfasan R). The resulting mixture was mixed for approximately 1 1/2 minutes while the temperature was maintained below about 135C. Then taken from the mixer portion of the composition was analyzed as described herein.

EPDM compositions, prepared using the carbon blacks of the present invention described in Examples 1-8 had the performance shown in table 7.

They were also evaluated by the methods described EPDM composition, including control samples AD carbon black. The results are shown in Tables 8-13, wherein the comparison between the compositions of EPDM, containing carbon blacks of the present invention and EPDM compositions, containing the most appropriate control carbon black.

The results presented in Table 8 show that at a level of 200 parts of carbon black per 100 parts of EPDM rubber compositions, which include carbon blacks of the present invention have lower viscosity and lower mixing energy. Thus, EPDM compositions, which include carbon blacks of the present invention exhibit better processing characteristics than the EPDM compositions, containing the control carbon black.

The results presented in Table 9 show the advantage of using carbon black in accordance with the present invention in EPDM compositions for such use, where the critical requirement is the resistivity. As shown in the table, with a load of 150 parts / 100 parts of rubber, which is typical for use in a cooling hose, the composition EPDM, comprising carbon blacks of the present invention has a higher resistivity than composition EPDM, containing the control carbon black.

Also EPDM composition, containing carbon blacks of the present invention has lower viscosity and lower mixing energy than the EPDM composition, which includes a control carbon black. This indicates that EPDM compositions, which include carbon blacks of the present invention will have improved ability to handle than EPDM compositions, containing the control carbon black.

The results presented in Table 10 show that compression set EPDM composition, containing carbon black in accordance with the present invention is less than the EPDM composition, comprising a control carbon black. Thus, the EPDM composition, containing carbon black in accordance with the present invention is more resistant to permanent deformation. The resulting compositions are particularly suitable for sealing, in particular for door seals and gaskets for sealing.

The results presented in Table 11 show that the carbon blacks of the present invention provides improved gain properties, particularly higher modulus and high hardness, EPDM compositions when compared to thermal carbon blacks. Thus, carbon blacks of the present invention can successfully replace thermal black or a mixture of carbon blacks comprising thermal black, furnace carbon black.

The results presented in Table 12 show that the carbon blacks according to the present invention can be used instead of a mixture of thermal carbon black and SRF type carbon black (furnace black poluusilivayuschaya) to ensure a satisfactory degree of performance characteristics. EPDM compositions, comprising carbon black of Example 5 also demonstrate the profiles having textured matte finish when they are extruded or molded.