Method for forming dispersed carbon nanomaterials for use in polymer composites and coatings - Patent Application 20070122999

Abstract

This disclosure describes methods for deagglomerating, debundling, dispersing, and functionalizing carbon nanomaterials in a medium using processes that do not impair the properties of the carbon nanomaterials. Three exemplary types of carbon nanomaterials are conductive carbon black, graphene, and carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWCNTs). Once the carbon nanomaterials are dispersed in a medium, the resulting carbon nanomaterial dispersion can be subjected to further processing or blended with additional components to form polymer composites suitable for coating or molding into structural parts. The dispersed carbon nanomaterials can impart desirable mechanical and electrical properties, such as electrostatic dissipation and conductivity, to the resulting member or part.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 482,686, filed February 1, 2023, which is incorporated herein by reference in its entirety.

[0002] The present disclosure generally relates to novel methods and systems for deagglomerating, debundling, dispersing, and functionalizing carbon nanomaterials in a medium to form carbon nanomaterial dispersions useful for blending with additional components to form masterbatches useful in forming composites and coatings. More specifically, the present disclosure relates to novel methods and systems for forming carbon nanomaterial dispersions (i) comprising a multitude of zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles, and (ii) possessing conductive and static dissipative properties, where such carbon nanomaterial dispersions are subsequently blended with additional components to form masterbatches, which are then used to form polymer composites useful in forming articles and coatings. [Background technology]

[0003] In recent years, there has been significant interest in the electrical benefits of nanocarbon-based thermally responsive composites and coatings that use carbon nanomaterials, such as carbon nanotubes (CNTs), to achieve electrostatic dissipative (ESD) and conductive properties. However, working with carbon nanotubes and other similar nanomaterials and subsequently deagglomerating, debundling, and dispersing such carbon nanomaterials in a medium to form functional coatings and / or composites has proven challenging. For example, to form functional carbon nanotube composites, coatings, or thermoplastic materials, dry carbon nanotube powder is typically added to a liquid or molten resin mixture with stirring. Dry carbon nanotube powder is very light and fluffy and tends to become airborne even with minimal airflow or drafts. This not only results in the loss of potentially valuable material and impacts quality, but also poses environmental, health, and safety concerns. Excessive flammable airborne powder can pose an explosion hazard, and airborne carbon nanotube particles can pose a health risk to humans. Another problem is that adding CNTs to a resin mixture with stirring typically does not generate enough shear to achieve uniform dispersion of the carbon nanotubes. A third problem with adding CNTs to a resin mixture is processability: the viscosity increases over time with stirring, and the composite resin matrix often becomes too viscous, leading to inprocessibility.

[0004] Typical physical and chemical dispersion techniques for processing carbon nanotube composites include sonication and ball milling, but these methods can cause irreversible damage to the carbon nanotubes. Other methods, such as mechanical mixing, magnetic stirring, and high-shear stirring, are less damaging to the carbon nanotubes, but these methods often leave the carbon nanotubes bundled together. This is especially true for a specific class of carbon nanotubes known as single-walled carbon nanotubes (SWCNTs). Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, due to the above needs, there is a need in the industry for a repeatable method for deagglomerating, debundling, dispersing, and functionalizing carbon nanomaterials in a liquid or thermoplastic medium to form novel carbon nanomaterial dispersions that can subsequently be combined with additional components to form novel masterbatches useful for forming polymer composites used to form products and coatings with consistent and useful physical properties. Such a method is disclosed herein. [Means for solving the problem]

[0006] This disclosure describes several aspects of methods for deagglomerating, debundling, dispersing, and functionalizing carbon nanomaterials, such as carbon nanotubes, in a medium without damaging the properties or structure of the carbon nanomaterials. Once the carbon nanomaterials are dispersed in a medium, the resulting carbon nanomaterial dispersion can be blended with other components to form a masterbatch. Such masterbatches can subsequently be combined with additional components to form polymer composites and / or coatings designed for use in various manufacturing processes to produce coatings or specific structural parts useful in commercial applications (e.g., pickup truck boxes, battery housings, ladder rails, marine coatings, ESD floor coatings, etc.). Using carbon nanomaterial dispersions in masterbatches and subsequent composites can result in molded parts or coatings with desirable mechanical and electrical properties, such as static dissipation and conductivity. In one example, a planar milling process is used to mix the carbon nanomaterials with additional components to form the carbon nanomaterial dispersion. Such a process deagglomerates, debundles, and disperses the nanomaterials in a medium without damaging the nanomaterials. The resulting carbon nanomaterial dispersion can be mixed with additional ingredients, such as polyester resin and carbon black, using a turbine milling process to form a masterbatch. Such masterbatches can then be blended with other ingredients to form composites or coating materials for applications such as coatings, molded parts, and molded products. Examples of composites formed by the described processes include, but are not limited to, sheet molding compounds, bulk molding compounds, injection molding compounds, track molding compounds, compression molding compounds, wet mixes, resin infusions, and prepregs. Such composites are useful in a variety of manufacturing processes, including injection molding, pultrusion, compression molding, extrusion, sheet molding, and foam molding.

[0007] The accompanying drawings illustrate structures that, in conjunction with the detailed description set forth below, describe exemplary aspects of the disclosed systems, methods, and apparatus. Where appropriate, like elements are identified with the same or similar reference numerals. Elements shown as a single component may be replaced by multiple components. Elements shown as multiple components may be replaced by a single component. The drawings may not be to scale. The proportions of certain elements may be exaggerated for illustrative purposes. [Brief explanation of the drawings]

[0008] [Figure 1] 1 illustrates a schematic of the core chemical structure of polyhedral oligomeric silsesquioxanes (POSS). [Figure 2] This is an image of a three-roll mill. [Figure 3] 1 is a schematic diagram of a three-roll mill. [Figure 4] 1 shows images of two drawdowns made using an exemplary method. [Figure 5] 1 is a graph illustrating the relationship between resistivity and SWCNT concentration in epoxy composites. [Figure 6] 1 is a graph illustrating the relationship between resistivity and SWCNT concentration in epoxy composites. [Figure 7] 1 is a microscope image of SWCNT bundles. DETAILED DESCRIPTION OF THE INVENTION

[0009] This disclosure describes several embodiments of methods for deagglomerating, debundling, dispersing, and functionalizing carbon nanomaterials in a medium using processes that do not impair the properties of the carbon nanomaterials. Three exemplary types of carbon nanomaterials are conductive carbon black, graphene, and carbon nanotubes (CNTs), including, but not limited to, single-walled carbon nanotubes (SWCNTs). Once the carbon nanomaterials are dispersed in a medium, the resulting carbon nanomaterial dispersion can be subjected to further processing and / or blended with additional components to form polymer composites suitable for coating and / or molding structural parts. The dispersed carbon nanomaterials can impart desirable mechanical and electrical properties, such as electrostatic dissipation and conductivity, to the resulting member or component. The chemical components used to form the carbon nanomaterial dispersion can be blended using a planar milling process, such as a two-roll milling process or a three-roll milling process. The chemical components used to form a masterbatch can be blended using a mixing process followed by a turbine milling process. Depending on the specific application, this masterbatch can then be used at loadings of approximately 0.01% to 50% of the resin content in coating and / or composite formulations composed of resins, polymers, monomers, fillers, additives, etc.

[0010] In one aspect, the present invention fully describes a method for making a stable carbon nanomaterial dispersion for use in forming a masterbatch, comprising combining a plurality of carbon nanomaterials with a liquid medium and a polyhedral oligomeric silsesquioxane derivative, and blending the components using a planar milling process to form the carbon nanomaterial dispersion.

[0011] In one embodiment, methods for making stable carbon nanomaterial dispersions include, but are not limited to, C12-14 aliphatic monoglycidyl ether, trimethylopropane triacrylate, polyester resin, plasticizer, molten liquid polyethylene, xylene, styrene, tert-butylstyrene, polypropylene glycol, and / or PM acetate.

[0012] In one embodiment, a method for making a stable carbon nanomaterial dispersion, wherein the polyhedral oligomeric silsesquioxane derivatives include, but are not limited to, trans-cyclohexanediol isobutyl POSS, aminopropyl isobutyl POSS, glycidyl POSS, glycidyl polyethylene glycol POSS, and / or polyethylene glycol POSS.

[0013] In one embodiment, a method of making a stable carbon nanomaterial dispersion, wherein the plurality of carbon nanomaterials comprises carbon nanotubes.

[0014] In one embodiment, a method of making a stable carbon nanomaterial dispersion, wherein the plurality of carbon nanomaterials comprises single-walled carbon nanotubes.

[0015] In one embodiment, a method for making a stable carbon nanomaterial dispersion, wherein the ratio of components is 70% to 90% aliphatic monoglycidyl ether or ester, 1% to 20% polyhedral oligomeric silsesquioxane derivative, and 1% to 15% carbon nanomaterial.

[0016] In one aspect, the present invention includes a method for using a planar milling process to obtain optimal electrical conductivity using carbon nanomaterials for thermoset composite and coating applications.

[0017] In one embodiment, the method of use of the plane milling process is a two-roll milling process or a three-roll milling process.

[0018] In one aspect, the method of using the planar milling process further comprises combining the carbon nanomaterial dispersion with a thermosetting resin and carbon black, and blending the components to form a polymer composite to form a masterbatch.

[0019] In one embodiment, the method uses a planar milling process to form a thermoset resin that is a polyester resin.

[0020] In one embodiment, the method of using the planar milling process uses ratios of ingredients that are approximately 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% carbon nanomaterial dispersion.

[0021] In one aspect, the method of using a planar milling process uses a turbine milling process used to enhance debundling and exfoliation in helping to improve compatibility and electrical properties used in polymer composites.

[0022] In one aspect, using a planar milling process, additional high shear mixing is used to enhance debundling and exfoliation in helping to improve compatibility and electrical properties for use in polymer composites.

[0023] In one embodiment, using the planar milling process, the resulting masterbatch includes a multitude of zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles.

[0024] In one embodiment, using the planar milling process, the resulting masterbatch can be used at a concentration of 0.05% to 50% in a thermosetting resin used to produce polymer composites with ESD and / or conductive properties.

[0025] In one aspect, the method of using the planar milling process, the resulting polymer coating and / or composite material has conductive properties.

[0026] In one aspect, the method of using the planar milling process, the resulting polymer coating and / or composite material has static dissipative properties.

[0027] The apparatus, systems, arrangements, and methods disclosed herein are described in detail by way of examples and with reference to the drawings. It will be understood that changes can be made to the disclosed and described examples, arrangements, configurations, components, elements, devices, methods, materials, etc., and may be desirable for particular applications. In this disclosure, any identification of a particular technique, arrangement, method, etc., is either related to the specific example presented or is merely a general description of such technique, arrangement, method, etc. Specific details or identification of examples are not intended to be, and should not be construed as, essential or limiting unless specifically so designated. Selected examples of apparatus, arrangements, and methods for forming carbon nanomaterial dispersions of deagglomerated, debundled, dispersed, and functionalized carbon nanotubes and for mixing such carbon nanomaterial dispersions with additional components to form the dispersions and / or masterbatches are disclosed and described in detail below with reference to FIGS. 1-7.

[0028] It is desirable to form a masterbatch or concentrate of deagglomerated, debundled, and dispersed carbon nanomaterials in a medium, followed by the addition and blending of other ingredients to form polymer composites useful for coatings and / or molding various structural parts and products. However, prior art techniques present challenges in forming masterbatches. There are two typical problems of concern in preparing dispersions, masterbatches, or concentrates. The first is the challenging task of dispersing carbon nanomaterials, which requires breaking down and dispersing relatively large (micron-scale) aggregates into much smaller particles and bundles with average particle sizes in the range of several hundred nanometers. The second problem is the delamination or debundling of aggregates of small particles and chains held together by various forces, particularly π-π and van der Waals interactions. Carbon nanomaterials form bundles held together by π-π and van der Waals interactions, which are generally insoluble and not easily dispersed in monomers, polymers, and solvents. This presents a fundamental processing challenge. The devices, systems, arrangements, and methods disclosed herein use carbon nanotubes as an exemplary carbon nanomaterial. However, it will be understood that such devices, systems, arrangements, and methods apply equally to other carbon nanomaterials, such as fullerenes, quantum dots, graphene, and nanodiamonds and nanohorns. As known in the art, such nanomaterials may be arranged in zero, one, two, or three dimensions in physical structure. All such structures are applicable to the present disclosure.

[0029] To obtain optimal improvements in electrical, mechanical, or other properties through the use of carbon nanotubes, it is desirable to achieve a consistent, high level of dispersion and debundling. Furthermore, dispersions containing a large number of zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles dispersed throughout a medium are desirable. The methods disclosed herein achieve such a goal. For purposes of this disclosure, dispersion refers to the process of deagglomerating carbon nanotube bundles and dispersing them uniformly throughout a medium. In contrast, debundling refers to the process of separating bundles of individual strands into smaller bundles and / or individual strands. The end result should be a near-uniform distribution of nanoparticles throughout the monomer, solvent, and / or polymer medium.

[0030] Typical physical and chemical dispersion techniques for processing carbon nanomaterials include sonication and ball milling, but these methods can cause irreversible damage. Other methods, such as mechanical mixing, magnetic stirring, and high-shear stirring, are less damaging, but these methods often leave carbon nanoparticles clumped together. This is especially true for a specific class of carbon nanotubes called single-walled carbon nanotubes (SWCNTs).

[0031] Novel methods for dispersing or deagglomerating large (micron-scale) bundles of carbon nanotubes, including CNTs and SWCNTs, include planar milling processes such as three-roll (or two-roll) milling. Planar milling processes reduce damage to carbon nanomaterial particles while allowing for efficient deagglomeration. However, overcoming π-π and van der Waals interactions with any form of milling or dispersion is a much more challenging task. A common problem for material compounders is that when incorporating carbon nanotubes (masterbatch or dry) into coating or composite formulations at sufficiently high loadings to achieve the desired conductivity, the viscosity of the compound becomes so high that mixing or processing becomes difficult, if not impossible. This situation can render mixers and other equipment unusable for masterbatch mixing. This is because the surface area of ​​carbon nanomaterials is so large compared to their overall weight or volume that it increases exponentially as small agglomerates begin to deagglomerate.

[0032] A typical masterbatch formulation used in this manner would be as follows: 90% (w / w) low viscosity carrier resin or plasticizer and 10% (w / w) SWCNTs. In this example, the low viscosity carrier vehicle could be a plasticizer such as dioctyl terephthalate, or a reactive resin such as Aropol MR 17060, Polylite 32645-00, Multranol 3900, or a monofunctional epoxy diluent such as a C12-14 aliphatic monoglycidyl ether (e.g., Heloxy 8, Chemmod 8, Epodil 748, etc.), to name a few (among many other possibilities) commercially available examples. With regard to carbon nanotubes, interesting examples include Nano Carbon Matrix 2005-404 (MWCNT) from Interprome, OCSiAl, and Tuball® (SWCNT) from American Elements, to name a few of the many possible examples. Examples of mixtures or compounds that may exhibit the described difficulties are listed in the table below.

[0033] [Table 1]

[0034] One issue with the described examples is the difficulty of incorporating the SWCNTs into the batch. SWCNTs are very light and fluffy, and the particles easily become airborne during the blending process, resulting in material loss and poor quality, in addition to environmental, health, and safety concerns. Another issue is the very low weight of material added. In a production environment, it is difficult, if not impossible, to accurately meter such small amounts of material into a mixing or compounding process. Therefore, as mentioned above, material compounders have used carbon nanotube masterbatches to help reduce or eliminate the issues of airborne particles and / or metering them into the process. Examples of blends or compounds containing masterbatches are listed in the table below.

[0035] [Table 2]

[0036] In the above case, a 10% SWCNT masterbatch would likely consist of 90% C12-14 aliphatic monoglycidyl ether and 10% Tuball (SWCNT). Similar, if not identical, masterbatch formulations are available on the market (e.g., Matrix 203 from OCSiAl). By using commercially available masterbatches, compounders can avoid the issues of airborne particles and the challenge of metering and controlling extremely small amounts of dry carbon nanotubes into their processes. However, significant challenges remain, including the issue of high viscosity.

[0037] As mentioned previously, carbon nanomaterials, especially SWCNTs, can have extremely high surface areas. By comparison, carbon black, a pigment commonly used in plastics and coatings, has a typical particle size of 84 nanometers (nm) diameter and a surface area of ​​approximately 60 square meters per gram (m 2 / g). The very fine grades of carbon black used in automotive exterior coatings are at the extreme end of the carbon black spectrum, with a mean particle size of 9 nm and a surface area of ​​550 m 2 / g. Such carbon black pigments are typically considered to be very light, fluffy, difficult to wet, and difficult to disperse. In contrast, in dispersions using carbon nanotubes, the surface area of ​​the carbon nanotubes is 7000 m 2 / g is common. Thus, one nearly, if not entirely inevitable, consequence of adding a carbon nanotube masterbatch dispersion to a formulation as described is that the viscosity increases to the point where the material no longer flows and becomes unprocessable (this is similar to one of the problems associated with adding CNTs dry). In some cases, the viscosity can become so high that it can damage or destroy mixing and other processing equipment. For processing methods that do not increase the viscosity to the point where it is no longer processable, this typically means that the carbon nanotubes are not incorporated to a level that allows for the desired properties, particularly static dissipative conductivity.

[0038] One way material compounders have attempted to overcome this issue is by adding dispersants or surfactants to their compounds. This process helps in part by wetting the carbon nanotubes, thereby reducing the viscosity of the mixture. However, a drawback of wetting the carbon nanotubes is that it can sterically hinder point-to-point contact between the debundled strands or particles. Therefore, the chemistry of the surfactant or dispersant used can be critical in achieving electrical conductivity in the end use.

[0039] One class of molecules effective as dispersants is polyhedral oligomeric silsesquioxanes (POSS). The chemical structure of POSS is illustrated in Figure 1. POSS is a type of inorganic, three-dimensional nanostructured Si-O cage (formula [RSiO1.5]n, where n = 8, 10, and 12) surrounded by various organic groups, with an overall diameter of 1 nm to 3 nm. Because POSS has eight organic groups surrounding a cage-like core connected by Si-O-Si bonds, it is highly soluble in many organic and inorganic solvents. POSS molecules exhibit compatibility with other organic and inorganic molecules, depending on the specific structure and substituents of the POSS. However, achieving carbon nanotube dispersion using POSS is not a simple process, and the process of introducing carbon nanotubes into POSS is crucial. Controlling the chemical and physical interactions between the nanotubes and POSS molecules is crucial. Examples of how POSS can be used by material compounders are listed in the table below.

[0040] [Table 3]

[0041] Adding POSS to an epoxy system and then adding a SWCNT masterbatch to it can help bring the viscosity to a level where the material remains processable, but because the POSS is not miscible in the masterbatch dispersion, the optimal properties for viscosity and loading required for ESD are not achieved.

[0042] This disclosure describes an efficient and scalable method for dispersing carbon nanotubes using surfactants or "hyperdispersants." The loading of carbon nanotubes in the hyperdispersants ranges from 0.01% to 15% by weight. High shear mixing, such as a two-roll or three-roll mill, is used to combine the POSS chemicals with the carbon nanotubes and SWCNTs. Examples of compositions tested are listed below.

[0043] [Table 4]

[0044] [Table 5]

[0045] [Table 6]

[0046] In the above example, some possible plasticizers include dioctyl terephthalate, dioctyl sebacate, or dibutyl phthalate, while some possible monomers or diluents include trimethylolpropane diacrylate (for unsaturated curing) or C12-14 aliphatic monoglycidyl ether (for epoxide polymerization).

[0047] Two factors to consider in debundling and dispersing carbon nanotubes are the applied shear stress and dispersion chemistry. While shear stress is required for debundling, a good, effective additive environment stabilizes the carbon nanotubes and prevents re-agglomeration due to high van der Waals forces. With these considerations in mind, a flat blade is used to mix the carbon nanotubes into the additive and monomer, polymer, and solvent solution. This suspension can then be processed on a two-roll or three-roll mill. Below are some examples of using carbon nanotube dispersions to achieve electrical properties in composite formulations.

[0048] Generally, dry carbon nanotubes are incorporated into a resin matrix under high shear agitation and subsequently dispersed via high shear mixing, such as three-roll and two-roll mixing, to avoid the introduction of undesirable defects. Such processes can be accomplished in multiple stages.

[0049] The first step is to incorporate the carbon nanomaterial into a liquid medium. For example, carbon nanotubes and SWCNTs are both extremely light and fluffy materials. Even opening a container of carbon nanotubes can easily cause very slight air currents to cause small, light aggregates of carbon nanotubes to become airborne. Therefore, introducing carbon nanotubes into a liquid resin or solvent before and during mixing must be carried out under carefully controlled conditions. One method for preparing a premix of carbon nanotubes and liquid (resin, monomer, additive) suspension is to use a Cowles blade at minimum speed stirring (100-300 revolutions per minute) and a mixing blade that is 1 / 3 the diameter of the mixing vessel. An exemplary process is as follows: (1) weigh 90 parts by weight of resin into the mixing vessel; (2) attach the mixing vessel to a mixer in a fume hood with carefully controlled airflow; (3) stir at low speed; (4) pre-weigh and add carbon nanotubes to the batch under minimal airflow; and (5) add the carbon nanotubes to the batch under minimal agitation until blended.

[0050] Mixing during the initial stages of processing is maintained at very low shear because shear exposes a larger surface area, significantly increasing the viscosity and thixotropy of the mixture. Due to the high surface area of ​​carbon nanotubes, excessive viscosity and thixotropy during the mixing process can prevent or hinder successful incorporation of the dry carbon nanotubes into the liquid phase mixture. A disk without a flat blade can be used in the mixer, or a paint shaker can be used instead of the mixer, thereby reducing the amount of shear the batch experiences when incorporating the carbon nanotubes into the liquid. As long as shear is kept to a minimum during this stage, any mixing technique can be utilized, including, but not limited to, planetary mixers, ribbon blenders, etc. A dispersant or POSS is typically present in the liquid mixture when the carbon nanotubes are introduced. This is done prior to deagglomeration, debundling, and dispersion to achieve effective results.

[0051] The second stage is the deagglomeration, debundling, and dispersion of the carbon nanotubes. This can be achieved through the use of a three-roll mill. Figure 2 shows an image of a three-roll mill. The material feed area, or "nip" area, is located near the rear of the mill. Between the rear and front of the mill are three rolls (feed roll, center roll, and apron roll). The apron is located at the very front of the mill, where the processed material is collected at the end of the process. Figure 3 shows a schematic diagram of a three-roll mill. The mixture is fed into the feed area (1) between the feed roll (2) and the center roll (3). This is sometimes referred to as the "nip" area because it is located between two nips on either side. Initially, most of the material remains in the feed area, while a small amount passes through the first high-shear nip (4) and remains attached to the rollers. This is because it can alternatively be recycled back to the feed area by the feed roll or advanced to the second nip (5) by the center roll. After passing through the second nip, the material is either recycled to the feed area again by the central roll, or adheres to the apron roll (6) and is removed by the apron knife edge (7) for collection and quality control.

[0052] Following the mixing stage, there are four parameters that influence the outcome of the planar milling process (e.g., processing through a three-roll mill) where the nanotubes are deagglomerated, debundled, and dispersed: (i) the rotational tip speed of the rolls, (ii) the gap between the rolls, (iii) the resulting shear rate as a combination of the tip speed and the gap between the rolls, and (iv) the number of times the material passes between each roll and is deposited onto the apron. In the case of three-roll milling, the maximum shear occurs in the region between adjacent rollers, known as the nip. The nip width can be adjusted to balance the requirements for thick flake throughput and high applied shear stress.

[0053] The liquid masterbatch described above can be introduced into the feed zone of a three-roll mill and processed over three passes using the three-roll mill shown in Figure 3. The tip speed and therefore the resulting shear rate is important, and such shear rate can be as low as 100 s depending on the roll and gap distance. -1 ~600000s -1 may vary.

[0054] In one example, a stable SWCNT dispersion can be blended with an epoxy resin at various ratios (90 ppm (wt / wt) to 5000 ppm (wt / wt)) and cured using triethylenetetramine at a 1:1 stoichiometry. Samples can be prepared in 2-inch diameter Petri dishes, and a 20-mil drawdown can be made on a Leneta chart. Samples can be cured at 65°C.

[0055] The test method for determining the electrical resistivity of a sample involves: (1) measuring the thickness of the cured sample via digital calipers, sandwiching it between two 75 mm square copper plates (where the copper plates were coated with a conductive adhesive to ensure uniform contact and had electrodes attached to them), and measuring the resistivity using a Ransburg resistivity meter; and (2) for the cured drawdown, connecting electrodes to the panel approximately 4 cm apart via electrical adhesive, and measuring the resistivity. Two examples of instruments that can be used are the Ransburg and Sperry Model DM-350A mentioned above.

[0056] Two images of drawdowns of SWCNT hyperdispersants in polymer composites prepared using the exemplary method are shown in Figure 4 (Sample 1 on the left and Sample 2 on the right). Certain property results for these samples are shown below.

[0057] The table below shows the resistivity of several samples of SWCNT hyperdispersants in polymer composites prepared with various percentages of carbon nanotubes.

[0058] [Table 7]

[0059] FIG. 5 is a graph illustrating the relationship between resistivity and SWCNT concentration in epoxy composites, where Sample 2 is shown in red (top line) and Sample 1 is shown in green (bottom line).

[0060] FIG. 6 is a graph further illustrating the relationship between resistivity and SWCNT concentration in epoxy composites, where Sample 2 is shown in red (top line) and Sample 1 is shown in green (bottom line).

[0061] Figure 7 shows a microscopic image of SWCNT bundles. This image is a 2000x microscope image of a SWCNT dispersion via visible light optical transmission. The scale is shown in the bottom left. The SWCNTs shown in this image are concentrated at 0.4 wt % in an aqueous suspension.

[0062] In another embodiment, the carbon nanotube dispersion is formed for the purpose of subsequently blending the carbon nanotube dispersion with additional components to form a masterbatch, which is then blended with additional components to form a polymer composite useful for molding or otherwise forming coatings and / or structural parts and other products. In one example, the carbon nanotube dispersion comprises SWCNTs, C12-14 aliphatic monoglycidyl ether, and POSS in the ratios listed in the table below. The components are combined using high shear mixing using either a two-roll mill or a three-roll mill to achieve the desired deagglomeration, debundling, and dispersion of the SWCNTs.

[0063] [Table 8]

[0064] With respect to the C12-14 aliphatic monoglycidyl ether, it is understood that any suitable organic hydrocarbon can be substituted for the C12-14 aliphatic monoglycidyl ether to sufficiently form a carbon nanotube dispersion. Furthermore, in one embodiment of the present invention, carbon nanotubes are combined with a functionalized polyhedral oligomeric silsesquioxane in a non-aqueous medium. However, it is understood that a carbon nanotube dispersion according to the present invention can be combined with a functionalized polyhedral oligomeric silsesquioxane in an aqueous medium or without any liquid medium at all.

[0065] Once these ingredients are combined, thus sufficiently deagglomerating, debundling, and dispersing the SWCNTs, the carbon nanotube dispersion is combined with additional ingredients to form a masterbatch. In one example, the carbon nanotube dispersion is combined with polyester resin and carbon black in the ratios listed in the table below. The carbon nanotube dispersion can be combined with the polyester resin and carbon black using several mixing processes, such as turbine milling using blades or other such mixing implements, or basket milling. The resulting masterbatch contains a multitude of zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles dispersed throughout the masterbatch. The masterbatch can subsequently be used as a component to form a polymer composite suitable for use as a coating or to form a product using any number of manufacturing processes.

[0066] [Table 9]

[0067] The percentages listed in the above table are for illustrative purposes only. In other embodiments, the percentage of polyester resin may range from 75% to 94.9%, the percentage of carbon black may range from 5% to 25%, and the percentage of carbon nanomaterial dispersion may range from 0.1% to 5%. In some embodiments, the percentage of carbon nanomaterial dispersion can be in the range of 0.1% to 2.5%, 0.1% to 2%, 0.1% to 1.9%, 0.1% to 1.8%, 0.1% to 1.7%, 0.1% to 1.6%, 0.1% to 1.5%, 0.1% to 1%, or any single numerical descriptor within these ranges, such as 1.6% or 1.639%, and the carbon black can be in the range of 5% to 20%, 5% to 15%, 15% to 20%, or any single numerical descriptor within these ranges, such as 17% or 17.41%. Since the amounts of carbon nanomaterial dispersion and carbon black in the carbon nanomaterial dispersion vary, the remainder of the composition can be polyester resin. In some embodiments, the ratio of ingredients is approximately 50% to 94.9% thermosetting resin, 5% to 25% carbon black, and 0.1% to 25% carbon nanomaterial dispersion. In some embodiments, increasing or even decreasing the carbon nanotube concentration is required. Thus, compositions formulated according to embodiments of the present invention may contain carbon nanomaterial dispersion in the range of 0.01%, or 0.05% up to 50%. That is, for battery housings that need to have static-dissipative properties, a 10% by weight carbon nanomaterial dispersion is appropriate, while in other cases, such as incorporating CNTs into non-aqueous coatings, primarily thermoplastic and thermoset acrylics, and thermoset epoxies to produce static-dissipative coatings for safety applications, masterbatch loadings may range as low as 0.01% (nearly 100 ppm) of the final resin solids. On the other hand, depending on the resin requirements, it may be necessary to increase the carbon nanomaterial dispersion to 120 ppm CNT, or 40% of the masterbatch basis, which is encompassed by one aspect of the present invention.Thus, methods and formulations according to one aspect of the present invention may include approximately 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% carbon nanomaterial dispersion, or any subrange or specific value within this disclosure, or 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% carbon nanomaterial dispersion.

[0068] It will be appreciated that the carbon nanomaterial dispersions and masterbatches described herein can be used in a wide variety of coatings and / or composites. These dispersions and masterbatches are designed for use by manufacturers or processors as deemed appropriate to form composites needed or desired to meet the requirements of an intended manufacturing process and / or the final product produced by such manufacturing process. These dispersions and masterbatches allow manufacturers and processors to use the dispersion or masterbatch as a separate component in a composite or other formulation without requiring any special precautions to ensure that the carbon nanomaterial is dispersed in the resulting composite. By using the dispersions and / or masterbatches described herein, the resulting polymer composites contain dispersed zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles, thereby providing excellent conductive and static-dissipative properties. Such polymer composites can be used to mold or coat structural components where conductive and / or static-dissipative properties are important, such as battery housings, static-dissipative flooring for industrial applications, automotive parts such as bumpers, covers for electrical components, and other such components.

[0069] The above description of the examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or limited to the forms described. Numerous modifications are possible in light of the above teachings, some of which have been discussed, and others will be apparent to those skilled in the art. These examples have been chosen and described in order to best explain the principles of the various examples as suited to the particular uses contemplated. Of course, the scope is not limited to the examples set forth herein, but may be employed in any number of applications and equivalent devices by those skilled in the art.

Claims

1. 1. A method of using a planar milling process to obtain carbon nanomaterial masterbatches for use in thermoset composite and coating applications, comprising: combining a plurality of carbon nanomaterials with a liquid medium and a polyhedral oligomeric silsesquioxane derivative; blending the ingredients using a planar milling process to form a carbon nanomaterial dispersion; preparing a carbon nanomaterial dispersion prepared by the method; Mixing the carbon nanomaterial dispersion with a thermosetting resin and carbon black; blending the carbon nanomaterial dispersion, the thermosetting resin, and the carbon black to form a carbon nanomaterial masterbatch; Including, wherein the obtained masterbatch contains a large number of zero-dimensional, one-dimensional, two-dimensional, and / or three-dimensional carbon nanoparticles; method.

2. 10. The method of claim 1, wherein the ratio of ingredients is approximately 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% carbon nanomaterial dispersion.

3. The method of claim 1 , wherein the plane milling process is a two-roll milling process, a three-roll milling process, or a turbine milling process.

4. 10. The method of claim 1, wherein the step of blending the carbon nanomaterial dispersion, the thermosetting resin, and the carbon black uses a turbine milling process or a basket milling process.

5. 2. The method of claim 1, wherein the carbon nanomaterial dispersion comprises 80 parts per hundred (PPH) C12-C14 aliphatic monoglycidyl ether, 10 PPH single-walled carbon nanotubes (SWCNTs), and 10 PPH polyhedral oligomeric silsesquioxane derivatives.

6. The method of claim 1 , wherein the carbon nanomaterial of the carbon nanomaterial dispersion is a single-walled carbon nanotube (SWCNT).

7. 10. The method of claim 1, further comprising forming a thermoset resin article comprising the carbon nanomaterial masterbatch of claim 1 in an amount of 0.01% to 50% relative to the amount of thermoset resin, such that the thermoset resin article has conductive properties.

8. 10. The method of claim 1, further comprising forming a polyester resin comprising adding the carbon nanomaterial masterbatch of claim 1 to a composite material required to form a polyester resin for molding or forming a structural part or coating.

9. 10. The method of claim 1, further comprising forming a coating or composite comprising the carbon nanomaterial masterbatch of claim 1 into a coating or polymer composite to form a coating or composite.

10. a carbon nanomaterial dispersion comprising a plurality of carbon nanomaterials, a liquid medium, and a polyhedral oligomeric silsesquioxane derivative; a thermosetting resin; Carbon black and A carbon nanomaterial masterbatch comprising a blend of:

11. The carbon nanomaterial masterbatch of claim 10, wherein the carbon nanomaterial dispersion comprises single-walled carbon nanotubes (SWCNTs).

12. 11. The carbon nanomaterial masterbatch of claim 10, wherein the carbon nanomaterial dispersion comprises 80 parts per hundred (PPH) of C12-C14 aliphatic monoglycidyl ether, 10 PPH of single-walled carbon nanotubes (SWCNTs), and 10 PPH of polyhedral oligomeric silsesquioxane derivatives.

13. 11. The carbon nanomaterial masterbatch of claim 10, wherein the ratio of the components is approximately 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% carbon nanomaterial dispersion.

14. 11. The carbon nanomaterial masterbatch of claim 10, wherein the ratio of the components is approximately 75% to 84.9% thermosetting resin, 15% to 20% carbon black, and 0.1% to 5% carbon nanomaterial dispersion.

15. 11. The carbon nanomaterial masterbatch of claim 10, further comprising a polyester resin to form a composition for molding, forming, or coating applications of structural parts, coatings, or polymer composites.

16. 1. A method for preparing a polymer composite material, comprising: providing a carbon nanomaterial dispersion comprising a plurality of carbon nanomaterials, a liquid medium, and a polyhedral oligomeric silsesquioxane derivative; deagglomerating, debundling, and dispersing the carbon nanotubes in the mixture to form a carbon nanomaterial dispersion; blending the carbon nanomaterial dispersion with a polymer resin and carbon black to form a carbon nanomaterial dispersion; combining the carbon nanomaterial dispersion with a polymer resin and carbon black to form a polymer composite for molding or coating a structural part; A method comprising:

17. The method of claim 16 , wherein the polymer resin is a thermosetting resin.

18. The method of claim 16 , wherein the polymer resin is a coating.

19. 17. The method of claim 16, wherein the step of deagglomerating, debundling, and dispersing the carbon nanotubes in the mixture to form a carbon nanomaterial dispersion is performed by a planar milling process, and the step of blending the carbon nanomaterial dispersion with a polymer resin and carbon black to form a carbon nanomaterial dispersion is performed by a turbine milling process or a basket milling process.

20. 17. The method of claim 16, wherein the proportions of the components are approximately 25% to 94.95% thermosetting resin, 5% to 25% carbon black, and 0.05% to 50% of the carbon nanomaterial dispersion.

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