Methods for producing carbon nanotube, and similar NANO- and micro- particle masterbatch as an additive for rubber or elastomer applications and compositions therefor

Abstract

Disclosed herein are compositions, formulations, and methods for manufacturing a resulting formulation, the method comprising: dispersing nanoparticles, microparticles, or both in a liquid medium to produce a nano- or micro-particle dispersion; mixing the nano- or micro-particle dispersion with a latex emulsion to produce a mixture; coagulating the mixture to produce a coagulated mass; breaking the coagulated mass into particles having a threshold particle size distribution; and integrating the particles into a formulation comprising rubber, elastomer, or both to produce the resulting formulation.

Description

METHODS FOR PRODUCING CARBON NANOTUBE, AND SIMILAR NANO- AND MICRO- PARTICLE MASTERBATCH AS AN ADDITIVE FOR RUBBER OR ELASTOMER APPLICATIONS AND COMPOSITIONS THEREFORFIELD

[0001] The present invention relates to nano- or micro-material composites and in particular to a high-concentration nano- or micro- particle masterbatch which can be micronized and added as an additive for elastomer applications.BACKGROUND

[0002] Carbon black (CB) serves as a universal filler in nearly all rubber compounds. Its primary role is to reinforce the rubber, augment its volume, enhance its physical attributes, and fortify the vulcanization process. By integrating carbon black as a filler, rubber compounds achieve heightened durability, resilience, and overall performance.

[0003] CNTs are an allotrope of carbon which form a tubular shape. The inherent high aspect ratio of CNTs, including variants such as Multi-walled CNTs, Single-walled CNTs, and branched CNTs, offers a promising alternative to carbon black as a filler in rubber and other elastomer compounds. This unique structural characteristic enables CNTs to impart superior properties to rubber formulations even at lower loading levels compared to traditional carbon black fillers. By integrating CNTs into rubber or elastomer compounds, manufacturers can achieve enhancements in mechanical strength, electrical conductivity, thermal stability, and other critical properties, leading to the development of high- performance rubber or elastomer products with reduced carbon filler content

[0004] However, the presence of strong van der Waals forces among carbon nanotubes (CNTs) often leads to their agglomeration, posing a significant challenge in achieving uniform dispersion within rubber or elastomer compounds. Unlike carbon black fillers, which readily disperse and mix homogeneously with rubber matrices using conventional compounding equipment, CNTs tend to form agglomerates, hindering their effectiveintegration into the rubber matrix. As a result, the dispersion of CNTs becomes uneven, leading to degradation in properties such as mechanical strength.SUMMARY OF PARTICULAR EMBODIMENTS

[0005] It will be appreciated by those skilled in the art that other variations of the embodiments described below may also be practiced without departing from the scope of the invention. Further note, these embodiments, and other embodiments of the present invention will become more fully apparent from a review of the description and claims which fol low.

[0006] In accordance with an aspect, there is provided a method for manufacturing a resulting formulation, the method including: dispersing nanoparticles, microparticles, or both in a liquid medium to produce a nano- or micro-particle dispersion; mixing the nano- or micro-particle dispersion with a latex emulsion to produce a mixture; coagulating the mixture to produce a coagulated mass; breaking the coagulated mass into particles having a threshold particle size distribution; and integrating the particles into a formulation comprising rubber, elastomer, or both to produce the resulting formulation.

[0007] In some embodiments, integrating the particles comprises mixing the particles with the formulation, wherein the formulation comprises a matrix comprising rubber, elastomer, or both.

[0008] In some embodiments, the formulation comprises at least one elastomer, the at least one elastomer being natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, neoprene, butyl rubber, halogenated butyl rubbers, styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubbers, EPM and EPDM rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene-vinyl acetate, Polypropylene, thermoplastic polymer or any combination thereof.

[0009] In some embodiments, the nanoparticles comprise carbon nanotubes (CNTs).

[0010] In some embodiments, the carbon nanotubes comprise multi-walled CNTs, single-walled CNTs, covalently functionalized CNTs, non-covalently functionalized CNTs, treated CNTs, branched CNTs, or any combination thereof.

[0011] In some embodiments, wherein the nanoparticles, microparticles, or both comprise nanotubes, nanorings, nanowires, nanorods, microtubes, microrings, microwires, microrods, or any combination thereof.

[0012] In some embodiments, wherein the nanoparticles are in a range from O.lnm to lOOnm.

[0013] In some embodiments, the microparticles are in a range from 0.1 pm to 100 pm.

[0014] In some embodiments, a temperature of the nano- or micro-particle dispersion is less than a boiling point of the liquid medium.

[0015] In some embodiments, the nano- or micro-particle dispersion comprises about 1 wt.% to about 60 wt. % nanoparticles, microparticles, or both.

[0016] In some embodiments, the latex emulsion comprises a water-based polymer emulsion.

[0017] In some embodiments, the latex emulsion comprises natural latex, styrene butadiene rubber (SBR), nitrile, chloroprene, vinyl acetate, ethylene vinyl acetate (EVA), or any combination thereof.

[0018] In some embodiments, the method further includes adjusting a ratio between the nano- or micro-particle dispersion and the latex emulsion to adjust at least one property of the produced material.

[0019] In some embodiments, the at least one property is electrical conductivity, mechanical strength, flexibility, or any combination thereof,

[0020] In some embodiments, the coagulating is performed by adding a coagulating agent.

[0021] In some embodiments, the coagulating agent comprises formic acid, acetic acid, sulphuric acid, citric acid, hydrochloric acid, smoke acid, or any combination thereof.

[0022] In some embodiments, the coagulating is by salt coagulation, thermo-coagulation, or both.

[0023] In some embodiments, the coagulating is by addition of an acid.

[0024] In some embodiments, the coagulating is by heating.

[0025] In some embodiments, the method further includes applying a first mechanical force to the coagulated mass to flatten or mold the coagulated mass.

[0026] In some embodiments, the method further includes drying the coagulated mass to produce a dried material before the breaking into particles.

[0027] In some embodiments, applying the first mechanical force is performed before the drying.

[0028] In some embodiments, the breaking the coagulated mass into particles is performed after the drying.

[0029] In some embodiments, the breaking the coagulated mass into particles comprises applying a mechanical force.

[0030] In some embodiments, the mechanical force comprises crushing, milling, grinding, cryogrinding, micronization, or any combination thereof.

[0031] In some embodiments, the integrating comprises applying a rubber compounding machine to the particles and the formulation.

[0032] In some embodiments, the rubber compounding machine comprises a two-roll mill, internal mixer, Banbury® mixer, a kneader, or any combination thereof.

[0033] In some embodiments, the threshold particle size distribution is less than or equal to about 200 pm.

[0034] In some embodiments, the drying reduces a moisture content in the coagulated mass to about 0.4% or less.

[0035] In some embodiments, the drying reduces a moisture content in the coagulated mass to about 0%.

[0036] In some embodiments, the integrating of the particles into the formulation to produce a material having about 0.01 wt.% to about 80 wt.% concentration of the particles.

[0037] In some embodiments, the mixture comprises a concentration of about 70 wt.% of nanoparticles, microparticles, or both.

[0038] In some embodiments, the ratio is in a range of about 1 wt.% to about 75 wt.%.

[0039] In some embodiments, the integrating of the particles produces a concentration of about 0.01 wt.% to about 80 wt.% of the particles in the formulation.

[0040] In accordance with an aspect, there is provided a formulation including: a latex emulsion comprising at least one nanoparticle, microparticle, or both dispersed in the latex emulsion.

[0041] In some embodiments, there is provided a particle formulation including: particles of the formulation dispersed in a second formulation comprising rubber, elastomer, or both.

[0042] In some embodiments, the second formulation comprises a matrix comprising rubber, elastomer, or both.

[0043] In some embodiments, the second formulation comprises at least one elastomer, the at least one elastomer being natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, neoprene, butyl rubber, halogenated butyl rubbers, styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubb rin rubber, acrylic rubber,silicone rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene-vinyl acetate, or any combination thereof.

[0044] In some embodiments, the at least one nanoparticles comprise carbon nanotubes (CNTs).

[0045] In some embodiments, the carbon nanotubes comprise multi-walled CNTs, single-walled CNTs, covalently functionalized CNTs, non-covalently functionalized CNTs, treated CNTs, branched CNTs, or any combination thereof.

[0046] In some embodiments, the at least one nanoparticles, the at least one microparticles, or both comprise nanotubes, nanorings, nanowires, nanorods, microtubes, microrings, microwires, microrods, or any combination thereof

[0047] In some embodiments, the at least one nanoparticles are in a range from 0. Inm to lOOnm.

[0048] In some embodiments, the at least one microparticles are in a range from 0.1 pm to 100 pm.

[0049] In some embodiments, the nano- or micro-particle dispersion comprises about 1 wt.% to about 60 wt. % nanoparticles, microparticles, or both.

[0050] In some embodiments, the latex emulsion comprises a water-based polymer emulsion.

[0051] In some embodiments, the latex emulsion comprises natural latex, styrene butadiene rubber (SBR), nitrile, chloroprene, vinyl acetate, ethylene vinyl acetate (EVA), or any combination thereof.

[0052] In some embodiments, a ratio between the at least one nanoparticle, microparticle, or both dispersed in the latex emulsion and the latex emulsion is selected to achieve a threshold level of a desired property for the particle formulation.

[0053] In some embodiments, the at least one property is electrical conductivity, mechanical strength, flexibility, or any combination thereof.

[0054] In some embodiments, the particles are less than or equal to about 200 pm.

[0055] In some embodiments, the moisture content is about 0.4% or less.

[0056] In some embodiments, the moisture content is about 0%.

[0057] In some embodiments, the particle formulation comprises a concentration of about 0.01 wt.% to about 80 wt.% of the particles.

[0058] In some embodiments, the latex emulsion comprises a concentration of about 70 wt.% of nanoparticles, microparticles, or both.

[0059] In some embodiment about 75 wt.%.

[0060] In some embodiments, there is provided a high concentration nano- or micro- particle masterbatch which can be integrated with a plurality of elastomers to create a blend of elastomer formulations. In some embodiments, the plurality of elastomers are selected from at least one of, but not limited to, natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, neoprene, butyl rubber, halogenated butyl rubbers, styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubbers, EPM and EPDM rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, and ethylene-vinyl acetate.

[0061] In some embodiments, there is described an elastomer formulation containing a nano- or micro- particle masterbatch, including a CNT rubber composite. In one embodiment, the nano- or micro- particles may be nanotubes, nanorings, nanowires, nanorods, microtubes, microrings, microwires, or microrods. The nano- or micro-particles may comprise carbon, such as CNTs and graphene variants. The CNTs can come in multiple variants including Multi-walled CNTs, Single-walled CNTs, Covalently or Non-covalently Functionalized CNTs, Treated CNTs, and branched CNTs. In some embodiments, the nanoparticles have dimensions ranging from 0. Inm to lOOnm. In some embodiments, the micro-particles have dimensions ranging from 0.1 and 100pm. In some embodiments, the final product consists of a CNT rubber composite.

[0062] In some embodiments, there is described a method for creating a nano- and micro- particle masterbatch and incorporating the masterbatch into an elastomer formulation. The method, in one embodiment, includes (a) dispersing the nano- or micro particles within a water or solvent medium, (b) integrating the nano- or micro- particle dispersion with a latex emulsion and fine-tuning the nano- or micro- particle concentration within the latex emulsion, (c) inducing coagulation between the nano- or micro- particle dispersion and the latex emulsion in order to create a harmonized, coagulated mass, (d) mechanically rolling the coagulated mass to achieve material flattening and molding, (e) drying the coagulated mass to eliminate residual moisture, (f) applying mechanical forces to break material into particles of a specifi -grinding the material toproduce micron-sized particles, and (h) incorporating the micronized particles into elastomer formulations.

[0063] In some embodiments of the methods of creating a nano- or micro- particle masterbatch, and incorporating the masterbatch into an elastomer formulation, the substances include: nano- or micro- particles, a water or solvent medium, a latex emulsion, in some embodiments a coagulating agent, and, in some embodiments, liquid nitrogen.BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In the drawings, preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood that the drawings are only for the purpose of illustration and as an aid to understanding and are not intended as a definition of the limits of the invention. The embodiments herein will be understood from the following description with reference to the drawings, in which:FIG. 1 is a flowchart outlining a method of producing a nano- or micro- particle elastomer composite.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0065] In this respect, before explaining at least one embodiment of the in vention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. In particular, all terms used herein are used in accordance with their ordinary meanings unless the context or definition clearly indicates otherwise. Also, unless indicated otherwise except within the claims the use of “or” includes “and” and v be construed as limitingunless expressly stated or the context clearly indicates otherwise (for example, “including”, “having”, “characterized by” and “comprising” typically indicate “including without limitation”). Singular forms included in the claims such as “a”, “an” and “the” include the plural reference unless expressly stated or the context clearly indicates otherwise. The term “about” means the number it is used to describe and + / - 10% of that number, unless otherwise indicated. Further, the stated features and / or configurations or embodiments thereof the suggested intent may be applied as seen fit to certain operating conditions or environments by one experienced in the field of art.

[0066] To address the challenge of the uneven dispersion and the formation of agglomerates of CNTs within rubber or elastomer compounds, previous approaches have attempted to develop CNT masterbatches by dispersing CNTs into a rubber matrix or rubber processing liquid beforehand. However, when these masterbatches were incorporated into the rubber matrix during compounding, the desired improvement in properties was not achieved at a commercial scale. This limitation stemmed from insufficient mixing time during compounding processes at the commercial level. Furthermore, the production of higher concentrations of CNT masterbatches proved to be challenging. This difficulty often resulted in the need for higher concentrations of masterbatched CNTs in the rubber matrix to achieve the desired properties. However, this approach sometimes led to the degradation of properties due to the introduction of excess rubber processing oil and other materials into the rubber matrix.

[0067] Therefore, in some embodiment described herein, a high-concentration nano- or microparticle masterbatch is prepared and subsequently micronized to mimic the behavior of carbon black particles. This process enables the nano- or micro- particle masterbatch to mix quickly and homogeneously with the rubber or elastomer matrix at an industrial scale. Each step in the method contributes to the final material’s composition and performance, making it suitable for various elastomer and other applications, from coatings to composites and beyond.

Claims

CLAIMSWhat is claimed is:

1. A method for manufacturing a resulting formulation, the method comprising: dispersing nanoparticles, microparticles, or both in a liquid medium to produce a nano- or micro-particle dispersion; mixing the nano- or micro-particle dispersion with a latex or water-based emulsion to produce a mixture; coagulating the mixture to produce a coagulated mass; and integrating the particles into a formulation comprising rubber, elastomer, or both to produce the resulting formulation.

2. The method of claim 1 , wherein integrating the particles comprises mixing the particles with the formulation, wherein the formulation comprises a matrix comprising rubber, elastomer, or both.

3. The method of claim 1 or 2, wherein the formulation comprises at least one elastomer, the at least one elastomer being natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, neoprene, butyl rubber, halogenated butyl rubbers, styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubbers, EPM and EPDM rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylenevinyl acetate, or any combination thereof.

4. The method of any one of claims 1 to 3, wherein the nanoparticles comprise carbon nanotubes (CNTs).

5. The method of claim 4, wherein the carbon nanotubes comprise multi-walled CNTs, singlewalled CNTs, covalently functionalized CNTs, non-covalently functionalized CNTs, treated CNTs, branched CNTs, or any combination thereof.

6. The method of any one of claims 1 to 5, wherein the nanoparticles, microparticles, or both comprise nanotubes, nanorings, nanowires, nanorods, microtubes, microrings, microwires, microrods, or any combination thereof.

7. The method of any one of claims 1 to 6, wherein the nanoparticles are in a range from 0.1 nm to lOOnm.

8. The method of any one of claims 1 to 7, wherein the microparticles are in a range from 0. 1 pm to 100 pm.

9. The method of any one of claims 1 to 8, wherein a temperature of the nano- or microparticle dispersion is less than a boiling point of the liquid medium.

10. The method of any one of claims 1 to 9, wherein the nano- or micro-particle dispersion comprises about 1 wt.% to about 60 wt. % nanoparticles, microparticles, or both.

11. The method of any one of claims 1 to 10, wherein the latex emulsion comprises a waterbased polymer emulsion.

12. The method of any one of claims 1 to 11, wherein the latex emulsion comprises natural latex, styrene butadiene rubber (SBR), nitrile, chloroprene, vinyl acetate, ethylene vinyl acetate (EVA), or any combination thereof.

13. The method of any one of claims 1 to 12, further comprising adjusting a ratio between the nano- or micro-particle dispersion and the latex emulsion to adjust at least one property of the produced material.

14. The method of claim 13, wherein the at least one property is electrical conductivity, mechanical strength, flexibility, or any combination thereof.

15. rhe method of any one of claims 1 to 14, wherein the coagulating is performed by adding a coagulating agent.

16. The method of claim 15, wherein the coagulating agent comprises formic acid, acetic acid, sulphuric acid, citric acid, hydrochloric acid, smoke acid, or any combination thereof.

17. The method of any one of claims 1 to 16, wherein the coagulating is by salt coagulation, thermo-coagulation, or both.

18. The method of any one of claims 1 to 17, wherein the coagulating is by addition of an acid.

19. The method of any one of claims 1 to 18, wherein the coagulating is by heating.

20. The method of any one of claims 1 to 19, further comprising applying a first mechanical force to the coagulated mass to flatten or mold the coagulated mass.

21. The method of any one of claims 1 to 20, further comprising drying the coagulated mass to produce a dried material before the breaking into particles.

22. The method of claim 21 as it depends from claim 20, wherein the applying the first mechanical force is performed before the drying.

23. The method of claims 21 or 22, wherein the breaking the coagulated mass into particles is performed after the drying.

24. The method of 1 to 23, wherein the breaking the coagulated mass into particles comprises applying a mechanical force.

25. The method of claim 24, wherein the mechanical force comprises crushing, milling, grinding, cryo-grinding, micronization, or any combination thereof.

26. The method of any one of claims 1 to 25, wherein the integrating comprises applying a rubber compounding machine to the particles and the formulation.

27. The method of claim 26, wherein the rubber compounding machine comprises a two-roll mill, internal mixer, Banbury® mixer, a kneader, or any combination thereof.

28. The method of any one of claims 1 to 27, wherein the threshold particle size distribution is less than or equal to about 200 pm.

29. The method of any one of claims 21 to 27, wherein the drying reduces a moisture content in the coagulated mass to about 0.4% or less.

30. The method of any one of claims 1 to 29, wherein the integrating of the particles into the formulation to produce a material having about 0.01 wt.% to about 80 wt.% concentration of the particles.

31. The method of any one of claims 1 to 30, wherein the mixture comprises a concentration of about 70 wt.% of nanoparticles, microparticles, or both.

32. The method of any one of claims 12 to 31 , wherein the ratio is in a range of about 1 wt.% to about 75 wt.%.

33. The method of any one of claims 1 to 32, wherein the integrating of the particles produces a concentration of about 0.01 wt.% to about 80 wt.% of the particles in the formulation.

34. A formulation comprising: a latex emulsion comprising at least one nanoparticle, microparticle, or both dispersed in the latex emulsion.

35. A particle formulation comprising:particles of the formulation of claim 34 dispersed in a second formulation comprising rubber, elastomer, or both.

36. The particle formulation of claim 35, wherein the second formulation comprises a matrix comprising rubber, elastomer, or both.

37. The particle formulation of claim 35 or 36, wherein the second formulation comprises at least one elastomer, the at least one elastomer being natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, neoprene, butyl rubber, halogenated butyl rubbers, styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubbers, EPM and EPDM rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene-vinyl acetate, or any combination thereof.

38. The formulation of any one of claims 34 to 37, wherein the at least one nanoparticles comprise carbon nanotubes (CNTs).

39. The formulation of claim 38, wherein the carbon nanotubes comprise multi-walled CNTs, single-walled CNTs, covalently functionalized CNTs, non-covalently functionalized CNTs, treated CNTs, branched CNTs, or any combination thereof.

40. The formulation of any one of claims 34 to 39, wherein the at least one nanoparticles, the at least one microparticles, or both comprise nanotubes, nanorings, nanowires, nanorods, microtubes, microrings, microwires, microrods, or any combination thereof.

41. The formulation of any one of claims 34 to 40, wherein the at least one nanoparticles are in a range from 0. Inm to lOOnm.

42. The formulation of any one of claims 34 to 41 , wherein the at least one microparticles are in a range from 0.1 pm to 100 pm.

43. The formulation of any one of claims 34 to 42, wherein the nano- or micro-particle dispersion comprises about 1 wt.% to about 20 wt. % nanoparticles, microparticles, or both.

44. The formulation of any one of claims 34 to 43, wherein the latex emulsion comprises a water-based polymer emulsion.

45. The formulation of any one of claims 34 to 44, wherein the latex emulsion comprises natural latex, styrene butadiene rubber (SBR), nitrile, chloroprene, vinyl acetate, ethylene vinyl acetate (EVA), or any combination thereof.

46. The formulation of any one of claims 34 to 45, wherein a ratio between the at least one nanoparticle, microparticle, or both dispersed in the latex emulsion and the latex emulsion is selected to achieve a threshold level of a desired property for the particle formulation of claim 35.

47. The formulation of claim 46, wherein the at least one property is electrical conductivity, mechanical strength, flexibility, or any combination thereof.

48. The particle formulation of any one of claims 35 to 47, wherein the particles are less than or equal to about 200 pm.

49. The particle formulation of any one of claims 35 to 48, wherein the moisture content is about 0.4% or less.

50. The particle formulation of any one of claims 35 to 49, wherein the particle formulation comprises a concentration of about 0.01 wt.% to about 80 wt.% of the particles.

51. The formulation of any one of claims 34 to 50, wherein the latex emulsion comprises a concentration of about 70 wt.% of nanoparticles, microparticles, or both.

52. The formulation of claim 46, wherein the ratio is in a range of about 1 wt.% to about 75 wt.%.

3. The method of any one of claims 1 - 33, further comprising the step of breaking the coagulated mass into particles having a threshold particle size distribution prior to integrating the particles into a formulation.

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