Master batch production system and method

Abstract

The invention discloses a master batch production system and method. A method for producing a masterbatch includes feeding (e.g., continuously feeding) a first composition containing an elastomeric latex (e.g., natural rubber latex) to a coagulation chamber; and feeding (e.g., continuously feeding) a second composition containing a particulate filler (e.g., carbon black) to the condensation chamber. Carbon black is fed directly from the ultrasound processing chamber to the coagulation chamber and / or the ultrasound processing device facilitates ultrasonic mixing within the coagulation chamber. The first composition and the second composition are mixed in a coagulation chamber to form a masterbatch. The second composition may be fed to the coagulation chamber at a pressure of at least 300 psig and / or at a speed of at least about 100 feet / sec. The masterbatch may be dry-blended with an additional elastomer to form an elastomeric composite blend.

Description

Technical Field

[0001] The present technology relates to a system for producing a masterbatch, a method for producing a masterbatch, and a method for producing an elastomeric composite blend. Background Art

[0002] When producing certain masterbatches (e.g., carbon black / natural rubber masterbatches), breaking up particulate filler agglomerates and keeping the filler dispersed prior to mixing with the elastomer latex is a challenge. For example, carbon black tends to agglomerate in aqueous media due to its hydrophobic nature.

[0003] It would be desirable to develop new systems and methods for maintaining a desired particle packing morphology and size distribution prior to injecting the particle packing into a coagulation chamber. Summary of the invention

[0004] In some embodiments, a system for producing a masterbatch is disclosed. The system includes a coagulation chamber having a first inlet and a second inlet; an elastomer latex source in fluid communication with the first inlet; an ultrasonic treatment chamber in direct fluid communication with the second inlet; and a particle slurry source configured to provide the particle slurry to the ultrasonic treatment chamber.

[0005] The source of particulate slurry may be a carbon black slurry tank.

[0006] In some embodiments, the system further includes a high shear mixer between the carbon black slurry tank and the ultrasonic treatment chamber.

[0007] The system may further include a pump (eg, a positive displacement pump) between the carbon black slurry tank and the ultrasonic treatment chamber.

[0008] In other embodiments, a method for producing a masterbatch is disclosed. The method includes: feeding (e.g., continuously feeding) a first composition containing an elastomer latex to a coagulation chamber; and feeding (e.g., continuously feeding) a second composition containing a particulate filler from an ultrasonic treatment chamber to the coagulation chamber. The first composition and the second composition are mixed in the coagulation chamber to form a masterbatch.

[0009] In some embodiments, the particulate filler includes carbon black.

[0010] The elastomer latex may include natural rubber.

[0011] In some embodiments, the second composition is fed to the coagulation chamber at a pressure of at least 300 psig (eg, about 500 psig to about 5,000 psig).

[0012] The second composition can be fed into the coagulation chamber at a velocity of at least about 100 ft / sec (eg, about 100 ft / sec to about 800 ft / sec).

[0013] In a further embodiment, a method for producing an elastomeric composite blend is disclosed. The method includes: feeding a first composition containing an elastomeric latex into a coagulation chamber; and feeding a second composition containing a particulate filler from an ultrasonic treatment chamber into the coagulation chamber. The first composition and the second composition are mixed in the coagulation chamber to form a masterbatch. The method further includes dry blending the masterbatch with an additional elastomer to form an elastomeric composite blend.

[0014] In some embodiments, the additional elastomer includes natural rubber, chlorinated natural rubber, or a homopolymer, copolymer, or terpolymer of one or more of the following: 1,3-butadiene, styrene, isoprene, isobutylene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, ethylene and / or propylene.

[0015] The elastomeric blend may contain from about 30 to about 85 phr of the particulate filler.

[0016] In further embodiments, masterbatches and elastomeric composite blends prepared by the methods are disclosed.

[0017] The present invention discloses the following embodiments:

[0018] 1. A system for producing a masterbatch, comprising:

[0019] a condensation chamber comprising a first inlet and a second inlet;

[0020] a source of elastomeric latex in fluid communication with the first inlet;

[0021] a sonication chamber in direct fluid communication with the second inlet and / or a sonication device for promoting ultrasonic mixing within the coagulation chamber; and

[0022] A particle slurry source is configured to provide the particle slurry to the ultrasonic treatment chamber.

[0023] 2. The system of embodiment 1, wherein the particulate slurry source comprises a carbon black slurry tank.

[0024] 3. The system of embodiment 2 further includes a high shear mixer between the carbon black slurry tank and the ultrasonic treatment chamber.

[0025] 4. The system of embodiment 2 further includes a pump between the carbon black slurry tank and the ultrasonic treatment chamber.

[0026] 5. The system of embodiment 4, wherein the pump is a positive displacement pump.

[0027] 6. A method for producing a masterbatch, the method comprising:

[0028] feeding a first composition comprising an elastomeric latex into a coagulation chamber; and

[0029] feeding a second composition comprising a particulate filler;

[0030] wherein the first composition and the second composition are mixed in a coagulation chamber to form a masterbatch; and

[0031] Wherein the second composition is fed from the ultrasonic treatment chamber to the coagulation chamber and / or the ultrasonic generator promotes ultrasonic mixing within the coagulation chamber.

[0032] 7. The method of embodiment 6, wherein the particulate filler comprises carbon black.

[0033] 8. The method of embodiment 6, wherein the elastomer latex comprises natural rubber.

[0034] 9. The method of embodiment 6, wherein the second composition is fed to the coagulation chamber at a pressure of at least 300 psig.

[0035] 10. The method of embodiment 9, wherein the pressure is in the range of about 500 to about 5,000 psig.

[0036] 11. The method of embodiment 6, wherein the second composition is fed to the coagulation chamber at a velocity of at least about 100 feet per second.

[0037] 12. The method of embodiment 11, wherein the velocity is in the range of about 100 ft / sec to about 800 ft / sec.

[0038] 13. The method of embodiment 6, wherein the first composition is continuously fed to the coagulation chamber.

[0039] 14. The method of embodiment 6, wherein the second composition is continuously fed to the coagulation chamber.

[0040] 15. A method for producing an elastomeric composite blend, the method comprising:

[0041] feeding a first composition comprising an elastomeric latex into a coagulation chamber; and

[0042] feeding a second composition comprising a particulate filler into a coagulation chamber, wherein the first composition and the second composition are mixed in the coagulation chamber to form a masterbatch; and

[0043] dry blending the masterbatch with an additional elastomer to form an elastomeric composite blend;

[0044] Wherein the second composition is fed from the ultrasonic treatment chamber to the coagulation chamber and / or the ultrasonic generator promotes ultrasonic mixing within the coagulation chamber.

[0045] 16. The method of embodiment 15, wherein the additional elastomer comprises at least one material selected from natural rubber, chlorinated natural rubber, or a homopolymer, copolymer or terpolymer comprising one or more of 1,3-butadiene, styrene, isoprene, isobutylene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, ethylene and propylene.

[0046] 17. The method of embodiment 15, wherein the particulate filler comprises carbon black.

[0047] 18. The method of embodiment 15, wherein the elastomer latex comprises natural rubber.

[0048] 19. The method of embodiment 15, wherein the second composition is fed to the coagulation chamber at a pressure of at least 300 psig.

[0049] 20. The method of embodiment 15, wherein the second composition is fed to the coagulation chamber at a velocity of at least about 100 feet per second.

[0050] These and other non-limiting aspects and / or objects of the present disclosure are more particularly described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The following is a brief description of the drawings, which are presented to illustrate exemplary embodiments disclosed herein and not to limit the same.

[0052] Figure 1 is a schematic flow diagram of a system and method for preparing an elastomer masterbatch according to some embodiments of the present disclosure. Specific implementation plan

[0053] The present disclosure may be understood more readily by reference to the following detailed description and accompanying drawings of desirable embodiments included in the disclosure.In the following specification and in the claims that follow, reference will be made to a number of terms which shall be defined to have the following meanings.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those of ordinary skill in the art. In the event of a conflict, this document (including definitions) shall prevail. Methods and materials are described below, although similar or equivalent methods and materials may be used in the practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated herein in their entirety by reference. The materials, methods and products disclosed herein are exemplary only and are not intended to be limiting.

[0055] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0056] The term "comprising" as used in the specification and claims may include the embodiments of "consisting of" and "consisting essentially of." As used herein, the terms "comprising," "including," "having," "having," "may," "containing," and variations thereof are intended to be open transition phrases that require the presence of specified ingredients / steps and allow for the presence of other ingredients / steps. However, such descriptions should be interpreted as also describing compositions, mixtures, or methods as "consisting of" and "consisting essentially of" the listed ingredients / steps, which only allow for the presence of the specified ingredients / steps, and any impurities that may result therefrom, and exclude other ingredients / steps.

[0057] Unless otherwise indicated, the numerical values ​​in the specification should be understood to include the same value when reduced to the same number of significant figures and values ​​that differ from the specified value by less than the experimental error of ordinary measurement techniques used to determine the particular value.

[0058] All ranges disclosed herein are inclusive of the recited endpoints and are independently combinable (e.g., the range "2 to 10" includes the endpoints 2 and 10 and all intermediate values). The endpoints of the ranges and any values ​​disclosed herein are not limited to the exact ranges or values; they are imprecise enough to include values ​​approximating these ranges and / or values.

[0059] As used herein, approximations can be used to modify any quantitative representation that may vary without causing a change in the basic function to which it relates. Therefore, the value modified by one or more terms such as "approximately" and "substantially" may not be limited to the specified exact value in some cases. The modifier "approximately" should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. For example, the phrase "about 2 to about 4" also discloses a range of "2 to 4". The term "approximately" may refer to plus or minus 10% of the value shown. For example, "about 10%" may refer to a range of 9% to 11%, and "about 1" may refer to 0.9-1.1.

[0060] For the enumeration of numerical ranges herein, each intermediate number with the same precision is expressly contemplated. For example, for the range of 6-9, in addition to 6 and 9, the numbers 7 and 8 are also contemplated, and for the range of 6.0-7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9 and 7.0 are expressly contemplated.

[0061] The present disclosure relates to a masterbatch prepared by mixing an elastomer latex (e.g., a latex containing natural rubber) with a slurry containing filler particles (e.g., carbon black particles). The slurry and latex are provided to a coagulation chamber, and the slurry can be provided at a much higher speed than the latex to promote high-speed collisions between the filler particles and the rubber particles. Immediately before the coagulation chamber, an ultrasonic treatment chamber is used to break up the particle filler agglomerates and / or keep them dispersed before mixing with the latex in the coagulation chamber. By including an ultrasonic treatment chamber, the particle filler primary particles will not have time to form aggregates / agglomerates before being locked into the coagulated rubber matrix, and the desired particle filler morphology and size distribution can be achieved in the slurry fed to the coagulation chamber.

[0062] In some embodiments, the sonication device is a continuous tubular sonication reactor (sono-reactor). The sonication device may include a dedicated sonicator.

[0063] Ultrasonic treatment conditions can be controlled by a dedicated ultrasonic generator. Depending on the design of the ultrasonic generator, it can operate at a single power and a single frequency. In some embodiments, the ultrasonic generator can produce broadband ultrasonic energy and can work in a multi-frequency mode, for example, from infrasound to the MHz domain.

[0064] exist Figure 1 In the embodiment depicted in , tank 1 receives a particulate filler and a carrier fluid (e.g., water). The tank can be a continuously stirred tank. The particulate filler slurry from tank 1 can be provided to a mixer 3 (e.g., a high shear mixer) before being provided to an ultrasonic treatment chamber 4. In some embodiments, a pump 2 (e.g., a positive displacement pump) is used to facilitate the provision of the particulate filler slurry downstream from tank 1. The ultrasonic treatment chamber 4 prevents the particulate filler particles from reaggregating before being injected into the coagulation chamber 5. In the coagulation chamber 5, the particulate slurry is typically provided at a higher speed and / or pressure than the elastic latex from the supply tank 6. The coagulated masterbatch from the coagulation chamber 5 can be provided to a subsequent material finishing process 7.

[0065] Although the depicted embodiment shows a sonication chamber upstream of the coagulation chamber, it should be understood that the inclusion of a sonication device to facilitate ultrasonic mixing within the coagulation chamber is also contemplated in lieu of or in conjunction with the sonication chamber.

[0066] In some embodiments, the coagulation chamber is built into or as part of the sonication chamber. In other embodiments, the coagulation chamber itself is the sonication chamber.

[0067] It should be understood that the phrase "an ultrasonic treatment chamber in direct fluid communication with the second inlet and / or an ultrasonic treatment device for promoting ultrasonic mixing within the coagulation chamber" covers the following embodiments: only an ultrasonic treatment chamber in direct fluid communication with the second inlet is used, only an ultrasonic treatment device for promoting ultrasonic mixing within the coagulation chamber is used, and both an ultrasonic treatment chamber in direct fluid communication with the second inlet and an ultrasonic treatment device for promoting ultrasonic mixing within the coagulation chamber are used.

[0068] The slurry can be used for masterbatch production immediately after preparation. The fluid conduits for conveying the slurry and any optional holding tanks, etc. should establish or maintain conditions that substantially maintain the dispersion of carbon black in the slurry. That is, a large amount of reaggregation or sedimentation of the particulate filler in the slurry should be prevented or reduced to the extent reasonably practicable. In some embodiments, all flow paths are smooth with smooth line-to-line interconnections.

[0069] A method for mixing various additives into an elastomer masterbatch can also be provided. An additive fluid including one or more additives can be fed into a mixing zone as a separate feed stream. If appropriate, one or more additives can also be premixed with the carbon black slurry, or more generally with the elastomer latex fluid. Subsequently, in a subsequent dry mixing step, the additives can be mixed into the masterbatch. Many additives are well known to those skilled in the art, and include, for example, antioxidants, antiozonants, plasticizers, processing aids (e.g., liquid polymers, oils, etc.), resins, flame retardants, filler oils, lubricants, and mixtures of any two or more thereof. The general purpose and selection of such additives are well known to those skilled in the art. With the benefit of this disclosure, their use in the systems disclosed herein will be readily understood. According to certain alternative embodiments, a curing agent can be mixed in a similar manner to produce a curable elastomer composite that can be referred to as a curable base compound.

[0070] The carbon black slurry or other particulate filler fluid may be supplied to the coagulation chamber at a pressure greater than about 100 psig, such as about 300 to 3000 psig, such as about 700 psig. In some embodiments, the liquid slurry is fed into the mixing zone at a velocity greater than 100 ft / sec, such as about 100 to about 800 ft / sec, or about 200 to 500 ft / sec.

[0071] Masterbatches produced using the systems and methods of the present disclosure can be used to produce elastomeric composite blends. Methods for producing such blends can include mixing (i) an elastomeric masterbatch produced in a continuous flow process involving a mixture of an elastomeric latex and a particulate filler fluid under turbulence levels and flow control conditions sufficient to achieve coagulation even without the use of conventional coagulants, and (ii) additional elastomers added to such elastomeric masterbatch in a dry blending step. Some optional aspects are disclosed in U.S. Pat. No. 6,075,084 to Mabry et al., which is incorporated herein by reference in its entirety.

[0072] The method of producing an elastomer composite blend advantageously provides flexibility to allow for better control of the distribution of fillers between two different elastomer phases within an elastomer composite blend, as shown in the example of an elastomer composite blend containing natural rubber, butadiene rubber ("BR") and carbon black filler. For certain applications, it is beneficial that the carbon black filler is primarily in the natural rubber phase of the elastomer composite blend. According to existing known dry methods / dry blending techniques, carbon black can be mixed with natural rubber using dry blending techniques, followed by the addition of BR and further dry blending. Disadvantageously, a large portion of the carbon black will migrate into the BR phase due to its affinity for the BR phase and the less desirable macroscopic dispersion of carbon black in the natural rubber phase. In contrast, the improved performance properties of comparable elastomer composite blends prepared by the wet mixing / dry mixing method disclosed herein show that more carbon black is retained in the natural rubber phase when carbon black is mixed with natural rubber in the initial wet mixing step and then BR is added in a subsequent dry mixing step.

[0073] According to the wet mixing step of the method disclosed herein, the feed rate of the latex fluid and the particle filler fluid to the mixing zone of the coagulum reactor can be accurately metered to achieve high yields, with almost no free latex and almost no undispersed filler in the product crumb at the discharge end of the coagulum reactor. Without wishing to be bound by theory, it is currently understood that a quasi-single-phase system is established in the mixing zone, except where coagulated solids are formed and / or downstream thereof in the coagulum zone. It is believed that the extremely high feed rate of the particle filler fluid into the mixing zone of the coagulum reactor and the speed difference relative to the latex fluid feed are significant in achieving sufficient turbulence, that is, the energy of the latex is sufficiently large to be sheared by the impact of the particle filler fluid jet so that the particles are completely mixed and dispersed into the latex fluid and coagulated. The high mixing energy produces a product masterbatch crumb with excellent dispersion and controlled product delivery. A coagulum is generated, and then a desirable extrudate is formed. The particulate filler fluid and the elastomer latex can be fed continuously, meaning that a continuous flow of the coagulation masterbatch is established from the mixing zone to the discharge end of the coagulation reactor while maintaining an uninterrupted flow of the feed fluid. Typically, the uninterrupted flow of the feed fluid and the simultaneous discharge of the coagulation masterbatch are maintained for one or more hours, such as more than 24 hours, and even perhaps a week or longer.

[0074] Although various embodiments may use a variety of different fillers and elastomers, for convenience, certain portions of the description of the methods and apparatus aspects of the present disclosure will describe a masterbatch containing natural rubber and carbon black. Thanks to the present disclosure, it will be within the capabilities of those skilled in the art to employ the methods and apparatus disclosed herein to produce masterbatches and elastomer composite blends containing many alternative or additional elastomers, fillers, and other materials according to the operating principles discussed herein. In short, the method for preparing an elastomer masterbatch involves simultaneously feeding (a) a slurry of carbon black or other filler; and (b) a natural rubber latex fluid or other suitable elastomer fluid into a mixing zone of a coagulation reactor. The coagulation zone extends from the mixing zone and may have a cross-sectional area that gradually increases in the downstream direction from the inlet end to the discharge end. The slurry may be fed into the mixing zone as a continuous high-speed jet of an injected fluid, while the natural rubber latex fluid is fed at a relatively low speed. The high velocity, flow rate, and particle concentration of the filler slurry are sufficient to cause mixing and high shear of the latex fluid, flow turbulence of the mixture in at least the upstream portion of the coagulation zone, and substantially complete coagulation of the elastomer latex before the discharge end. Thus, substantially complete coagulation can be achieved. The continuous flow method for producing an elastomer composite material includes continuously and simultaneously feeding a latex fluid and a filler slurry into a mixing zone of a coagulation reactor, establishing a continuous, semi-confined flow of a mixture of latex and filler slurry in the coagulation zone. Elastomer composite material crumbs in the form of "worms" or pellets are discharged from the discharge end of the coagulation reactor in a substantially constant flow, while the latex and carbon black slurry streams are continuously fed into the mixing zone of the coagulation reactor. It is worth noting that the piston-type flow and atmospheric or near-atmospheric conditions at the discharge end of the coagulation reactor are highly advantageous in facilitating the control and collection of the elastomer composite product, such as for immediate or subsequent further processing steps. The feed rate of the natural rubber latex fluid and the carbon black slurry to the mixing zone of the coagulation reactor can be accurately metered to achieve high yields, and there is almost no free latex and almost no undispersed carbon black in the product crumbs at the discharge end of the coagulation reactor. Without wishing to be bound by theory, it is believed that a quasi-single-phase system is established in the mixing zone, except where coagulated solids are formed and / or downstream thereof in the coagulation zone. It is believed that the extremely high feed rate of the carbon black slurry into the mixing zone of the coagulation reactor and the speed difference relative to the natural rubber latex fluid feed are significant in achieving sufficient turbulence, i.e., the latex is sheared with sufficient energy by the impact of the particle filler fluid jet so that the particles are fully mixed and dispersed in the latex fluid and coagulated. High mixing energy produces a novel product with excellent macroscopic dispersion and controlled product delivery. Coagulum is generated, and a desirable extrudate is subsequently formed.

[0075] The masterbatch prepared by the above-mentioned wet mixing techniques and equipment can be formed into an elastomeric composite blend by subsequent dry mixing with an additional elastomer. Thus, in some embodiments, the present disclosure relates to a wet / dry method. The dry mixing step of the wet / dry mixing method can be carried out with commercially available equipment and techniques, including, for example, a Banbury mixer, etc. The additional elastomer added during the dry mixing step of the wet / dry mixing method disclosed herein can be one or more elastomers that are the same or different from the one or more elastomers used to form the masterbatch. During the dry mixing step, other ingredients may also be added together with the additional elastomer, including, for example, filler oils, additional particulate fillers, curing agents, etc., in which additional particulate fillers are added during the dry mixing step. In those embodiments, such additional fillers may be the same or different from the one or more fillers used in the masterbatch formed by the wet mixing step.

[0076] Suitable elastomer latex fluids include both natural and synthetic elastomer latexes and latex blends. The latex is suitable for coagulation by a selected particulate filler and is suitable for the intended purpose or application of the final rubber product. With the benefit of this disclosure, it will be within the capabilities of those skilled in the art to select an elastomer latex or a suitable elastomer latex blend suitable for the methods and apparatus disclosed herein. Exemplary elastomers include, but are not limited to, rubber, the following polymers (e.g., homopolymers, copolymers, and / or terpolymers): 1,3-butadiene, styrene, isoprene, isobutylene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, ethylene and / or propylene, etc. The elastomer may have a glass transition temperature (Tg) measured by differential scanning calorimetry (DSC) of about -120°C to about 0°C. Examples include, but are not limited to, styrene-butadiene rubber (SBR), natural rubber and its derivatives such as chlorinated rubber, polybutadiene, polyisoprene, poly(styrene-co-butadiene) and oil-extended derivatives of any of them. Blends of any of the foregoing may also be used. The latex may be in an aqueous carrier liquid. Alternatively, the liquid carrier may be a hydrocarbon solvent. In any case, the elastomeric latex fluid must be suitable for controlled continuous feeding into the mixing zone at an appropriate rate, pressure, and concentration. Non-limiting examples of suitable synthetic rubbers include copolymers of about 10 to about 70 weight percent styrene and about 90 to about 30 weight percent butadiene, such as copolymers of 19 parts styrene and 81 parts butadiene, copolymers of 30 parts styrene and 70 parts butadiene, copolymers of 43 parts styrene and 57 parts butadiene, and copolymers of 50 parts styrene and 50 parts butadiene; polymers and copolymers of conjugated dienes, such as polybutadiene, polyisoprene, polychloroprene, and the like, and copolymers of such conjugated dienes with monomers containing olefinic groups copolymerizable therewith, such as styrene, methylstyrene, chlorostyrene, acrylonitrile, 2-vinyl-pyridine, 5-methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine, 2-methyl-5-vinylpyridine, alkyl-substituted acrylates, vinyl ketones, methylisopropenyl ketone, methyl vinyl ether, α-methylene carboxylic acids and their esters and amides such as acrylic acid and dialkylacrylic acid amides. Also suitable for use herein are copolymers of ethylene and other high alpha olefins such as propylene, butene-1 and pentene-1.

[0077] The additional elastomer added during the dry mixing step of the wet / dry mixing method can use any elastomer or elastomer mixture suitable for the intended use or application, including those listed for the wet mixing step above. According to some embodiments, the elastomer latex used in the wet mixing step is natural rubber latex, and the additional elastomer used in the dry mixing step is butadiene rubber (BR). In such embodiments, butadiene rubber can form a secondary phase or composition of an elastomer composite blend, such as 10 weight % to 50 weight % of total elastomer in the elastomer composite blend. According to some other embodiments, the elastomer latex used in the wet mixing step is natural rubber latex, and the additional elastomer used in the dry mixing step is styrene-butadiene rubber (SBR). In some embodiments, SBR can form a primary phase or composition of an elastomer composite blend, such as 50 weight % to 90 weight % of total elastomer in the elastomer composite blend. According to some other embodiments, the additional elastomer is natural rubber. According to some other embodiments, the elastomer latex used in the wet mixing step is butadiene rubber latex, and the additional elastomer used in the dry mixing step is SBR. In such embodiments, SBR can be 10 weight % to 90 weight % of the total elastomer in the elastomer composite blend. According to some other embodiments, the elastomer latex used in the wet mixing step is butadiene rubber latex, and the additional elastomer used in the dry mixing step is natural rubber. In such embodiments, natural rubber can be the minor component or phase of the elastomer composite blend, such as 10 weight % to 50 weight % of the total elastomer in the elastomer composite blend. According to some other embodiments using butadiene rubber latex in the wet mixing step, the additional elastomer is additional butadiene rubber. According to some other embodiments, the elastomer latex used in the wet mixing step is SBR, and the additional elastomer is butadiene rubber. In such embodiments, butadiene rubber can be 10 weight % to 90 weight % of the total elastomer in the elastomer composite blend. According to some other embodiments, the elastomer latex used in the wet mixing step is SBR, and the additional elastomer is natural rubber. In such embodiments, natural rubber can be the main component or phase, such as 50% to 90% by weight of the total elastomer in the elastomer composite blend. In some embodiments, SBR is used in both the wet mixing and dry mixing steps, thus being substantially 100% of the elastomer in the elastomer composite blend.

[0078] As further noted below, in addition to elastomer and filler, rubber composition can contain curing agent (curing agent), coupling agent and optional various processing aids, oil filler and antidegradant. In this regard, it should be understood that the elastomer composite blend disclosed herein includes vulcanized composition (VR), thermoplastic vulcanizate (TPV), thermoplastic elastomer (TPE) and thermoplastic polyolefin (TPO). TPV, TPE and TPO materials are further classified according to their ability to extrude and mold several times without substantially losing performance characteristics. Thus, when manufacturing elastomer composite blends, one or more curing agents can be used, such as sulfur, sulfur donor, activator, accelerator, peroxide and other systems for realizing the vulcanization of elastomeric composition.

[0079] When the elastomer latex used in the wet mixing step comprises natural rubber latex, the natural rubber latex may comprise field latex or latex concentrate (e.g., prepared by evaporation, centrifugation, or creaming). Natural rubber latex must of course be suitable for coagulation by carbon black. Latex is usually provided in an aqueous carrier liquid. Alternatively, the liquid carrier may be a hydrocarbon solvent. In any case, the natural rubber latex fluid must be suitable for continuous feeding into the mixing zone at an appropriate speed, pressure, and controlled concentration. The well-known instability of natural rubber latex is advantageously adapted because it is subjected to relatively low pressure and low shear in the entire system until it is entrained into the aforementioned semi-constrained turbulence when it encounters the extremely high speed and kinetic energy of the carbon black slurry in the mixing zone. In some embodiments, for example, natural rubber is fed into the mixing zone at a feed rate of about 3-12 feet / second, for example, about 4-6 feet / second, at a pressure of about 5psig. In some embodiments, natural rubber latex is fed to the mixing zone under negative pressure (e.g., -5 psig), wherein the vacuum is created by the ejector effect from the high velocity carbon black jet stream. With the benefit of this disclosure and knowledge of generally recognized selection criteria in the industry, it will be within the ability of those skilled in the art to select a suitable latex or latex blend.

[0080] The slurry may contain any suitable filler in a suitable carrier fluid. The choice of carrier fluid will depend primarily on the choice of particulate filler and system parameters. Aqueous and non-aqueous liquids may be used, with water being useful in many embodiments given its cost, availability, and suitability for use in the production of carbon black and certain other filler slurries.

[0081] When a carbon black filler is used, the choice of carbon black will depend primarily on the intended use of the elastomer composite blend. Optionally, the slurry further includes any material that can be slurried and fed to the mixing zone according to the principles disclosed herein. Suitable additional particulate fillers include, for example, conductive fillers, reinforcing fillers, fillers containing short fibers (usually having an L / D aspect ratio of less than 40), flakes, and the like. Thus, exemplary particulate fillers that can be used to produce elastomer masterbatches according to the methods and apparatus disclosed herein are carbon black, fumed silica, precipitated silica, coated carbon black, chemically functionalized carbon blacks such as those with attached organic groups, and silicon-treated carbon blacks, alone or in combination with one another. Silicon-treated carbon blacks, silicon-containing species such as silicon oxides or carbides, are distributed as an inherent part of carbon black on at least a portion of the carbon black aggregates. Conventional carbon black exists in the form of aggregates, wherein each aggregate consists of a single phase, and the single phase is carbon. The phase can exist in the form of graphite crystallites and / or amorphous carbon, and is generally a mixture of these two forms. As discussed elsewhere herein, carbon black aggregates can be modified by depositing silicon-containing species such as silicon dioxide on at least a portion of the surface of the carbon black aggregates. The result can be described as silicon-coated carbon black. The materials described herein as silicon-treated carbon blacks are not carbon black aggregates that have been coated or otherwise modified, but actually represent different types of aggregates. In silicon-treated carbon blacks, the aggregates contain two phases. One phase is carbon, which will still exist as graphite crystallites and / or amorphous carbon, and the second phase is silicon dioxide (and possible other silicon-containing species). Thus, the silicon-containing species phase of the silicon-treated carbon black is an inherent part of the aggregate; it is distributed throughout at least a portion of the aggregate. It should be understood that multiphase aggregates are completely different from the silicon dioxide-coated carbon blacks mentioned above, which consist of pre-formed single-phase carbon black aggregates with silicon-containing species deposited on their surfaces. Such carbon blacks can be surface-treated so as to place silica functional groups on the surface of the carbon black aggregates. In this method, an existing aggregate is treated so that silicon dioxide (and possibly other silicon-containing species) is deposited or coated on at least a portion of the surface of the aggregate. For example, an aqueous sodium silicate solution can be used to deposit amorphous silicon dioxide on the surface of carbon black aggregates in an aqueous slurry at a high pH (such as 6 or higher). More specifically, carbon black can be dispersed in water to obtain an aqueous slurry consisting of, for example, about 5% by weight of carbon black and 95% by weight of water. The slurry can be heated to above about 70°C, such as to 85-95°C, and the pH can be adjusted to above 6, such as to a range of 10-11, with an alkaline solution. A separate formulation is made of a sodium silicate solution and an acidic solution that brings the sodium silicate solution to a neutral pH, the sodium silicate solution containing the amount of silicon dioxide desired to be deposited on the carbon black. The sodium silicate and acid solution are added dropwise to the slurry, which is maintained at its starting pH with an acid or alkaline solution as appropriate. The temperature of the solution is also maintained.The recommended addition rate of the sodium silicate solution is to calibrate the dropwise addition so as to add about 3% by weight of silicic acid relative to the total amount of carbon black per hour. During the addition process, and after its completion, the slurry can be stirred for several minutes (e.g., 30) to several hours (i.e., 2-3). In contrast, silicon-treated carbon black can be obtained by manufacturing carbon black in the presence of a volatilizable silicon-containing compound. Such carbon black can be made in a modular or "staged" furnace carbon black reactor having a combustion zone, a subsequent diameter convergence zone, a raw material injection zone with a restricted diameter, and a reaction zone. The quenching zone is located downstream of the reaction zone. Typically, a quenching fluid (usually water) is sprayed into the stream of newly formed carbon black particles flowing out of the reaction zone. When producing silicon-treated carbon black, the previously mentioned volatilizable silicon-containing compound is introduced into the carbon black reactor at a position upstream of the quenching zone. The compounds that can be used are compounds that are volatile at the carbon black reactor temperature. Examples include, but are not limited to, silicates such as tetraethoxy orthosilicate (TEDS) and tetramethoxy orthosilicate, silanes such as tetrachlorosilane and trichloromethylsilane; and organosilicon polymers such as octamethylcyclotetrasiloxane (OMTS). The flow rate of the volatile compound will determine the weight percent of silicon in the treated carbon black. The weight percent of silicon in the treated carbon black is typically about 0.1% to 25%, such as about 0.5% to about 10%, and about 2% to about 6%. The volatile compound can be premixed with the carbon black forming feedstock and introduced into the reaction zone with the feedstock. Alternatively, the volatile compound can be introduced separately into the reaction zone upstream or downstream of the feedstock injection point.

[0082] As noted above, additives may be used, and in this regard, coupling agents used to couple silica or carbon black should be expected to be useful with silicon-treated carbon black.Carbon black and many additional suitable particulate fillers are commercially available and are known to those skilled in the art.

[0083] The selection of a mixture of particulate fillers or particulate fillers will depend primarily on the intended use of the elastomer composite blend. The particulate fillers used herein may include any material that can be slurried and fed to a mixing zone according to the principles disclosed herein. Suitable particulate fillers include, for example, conductive fillers, reinforcing fillers, fillers containing short fibers (typically having an L / D aspect ratio of less than 40), flakes, and the like. In addition to the above-mentioned carbon black and silica fillers, fillers may be formed of clay, glass, polymers such as aramid fibers, and the like. Thanks to the present disclosure, it will be within the capabilities of those skilled in the art to select particulate fillers suitable for the methods and apparatus disclosed herein, and it is expected that any filler suitable for an elastomer composition can be mixed into an elastomer composite using the teachings of the present disclosure. Of course, blends of the various particulate fillers discussed herein may also be used.

[0084] It will be appreciated that a carbon black having a lower surface area per unit weight may be used in a particulate slurry at a higher concentration to achieve the same coagulation efficacy as a lower concentration of a carbon black having a higher surface area per unit weight.

[0085] Prior to adding the additional elastomer in the dry mixing step of the wet / dry process disclosed herein, the masterbatch (or other elastomeric composite) produced by the wet mixing step is optionally subjected to any suitable further processing. Apparatus suitable for the dry mixing step is commercially available and will be apparent to those skilled in the art with the benefit of this disclosure. Suitable dry mixing equipment includes, for example, a Banbury mixer, an open mill, a roller mixer, and the like. The coagulum from the wet mixing step, with or without any further intermediate treatment, is introduced into a Banbury mixer or other mixing device with the additional elastomer in any suitable order and relative proportion suitable for the intended use or application. With the benefit of this disclosure, it will be within the capabilities of those skilled in the art to determine the appropriate order of addition and relative proportion of the wet mixed product and the additional elastomer. Similarly, with the benefit of this disclosure, it will be within the capabilities of those skilled in the art to select suitable additional ingredients to be added during the dry mixing step suitable for the intended use or application, such as extender oils, curing agents, and other additives known for the general type of elastomeric composites and elastomeric composite blends disclosed herein.

[0086] This written specification uses examples to disclose the present disclosure, including the best mode, and to enable any person skilled in the art to make and use the present disclosure. Other examples that occur to those skilled in the art are intended to be within the scope of the present disclosure if they have structural elements that are not different from the same concept or if they include equivalent structural elements with insubstantial differences. It is to be recognized that variations of the above-disclosed and other features and functions, or alternatives thereto, may be combined into many other different systems or applications. Various currently unforeseen or unexpected substitutions, modifications, changes or improvements may subsequently be made by those skilled in the art, which are also intended to be covered by the following claims.

Claims

1. A system for producing a masterbatch, comprising: A condensation chamber comprising a first inlet and a second inlet: a source of elastomeric latex in fluid communication with the first inlet; a sonication chamber in direct fluid communication with the second inlet and / or a sonication device for promoting ultrasonic mixing within the coagulation chamber; and A particle slurry source is configured to provide the particle slurry to the ultrasonic treatment chamber.

2. The system of claim 1, wherein the particulate slurry source comprises a carbon black slurry tank.

3. The system of claim 2, further comprising a high shear mixer between the carbon black slurry tank and the ultrasonic treatment chamber.

4. The system of claim 2, further comprising a pump between the carbon black slurry tank and the ultrasonic treatment chamber.

5. The system of claim 4, wherein the pump is a positive displacement pump.

6. A method for producing a masterbatch, the method comprising: feeding a first composition comprising an elastomeric latex into a coagulation chamber; and feeding a second composition comprising a particulate filler; wherein the first composition and the second composition are mixed in a coagulation chamber to form a masterbatch; and Wherein the second composition is fed from the ultrasonic treatment chamber to the coagulation chamber and / or the ultrasonic generator promotes ultrasonic mixing within the coagulation chamber.

7. The method of claim 6, wherein the particulate filler comprises carbon black.

8. The method of claim 6, wherein the elastomer latex comprises natural rubber.

9. The method of claim 6, wherein the second composition is fed to the coagulation chamber at a pressure of at least 300 psig.

10. A method for producing an elastomeric composite blend, the method comprising: feeding a first composition comprising an elastomeric latex into a coagulation chamber; and feeding a second composition comprising a particulate filler into a coagulation chamber, wherein the first composition and the second composition are mixed in the coagulation chamber to form a masterbatch; and dry blending the masterbatch with an additional elastomer to form an elastomeric composite blend; Wherein the second composition is fed from the ultrasonic treatment chamber to the coagulation chamber and / or the ultrasonic generator promotes ultrasonic mixing within the coagulation chamber.

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