Conformal coatings having low volatile organic compound content

Abstract

Disclosed is a coating composition comprising at least one film-forming component comprising a water-based carrier, a resin, and at least one additive, wherein the coating composition does not comprise a high volatile organic compound (VOC) content, and the resin is present in an amount and configured to form a conformal film when applied to a substrate at room temperature. Conformal coatings, methods of making the coating composition, and methods of using the coating composition to protect substrates, such as electronic devices, including printed circuit board assemblies (PCBA), from undesirable contaminants are also disclosed. Substrates coated with such conformal coatings are also disclosed.

Description

[Technical field]

[0001]

[01] The present disclosure generally relates to conformal coating compositions with low or no volatile organic compound (VOC) content that form deformable insulating films designed to protect substrates such as electronic devices or printed circuit board assemblies (PCBAs). The present disclosure also relates to methods of making such compositions that protect substrates such as electronic devices or PCBAs from contaminants by applying the compositions of the present disclosure to desired portions of the substrates such as printed circuit boards of electronic devices. The present disclosure also relates to substrates coated with conformal coatings using the compositions described. [Background technology]

[0002]

[02] Electronic devices are composed of conductive components that can be adversely affected by exposure to harsh environments. Exposure to liquids such as water often results in corrosion or shorting of these components, which ultimately destroys the functionality of the electronic device. Furthermore, while such devices are becoming more sophisticated with increasing functionality, they are also being used in more hostile environments, such as high humidity environments, corrosive gases, aerosolized or bulk liquids, or environments having conductive particulates that can degrade the functionality of the device.

[0003]

[03] Electronic devices will fail when exposed to these environments because the conductive medium can provide unintended current paths between components under bias. Most of these failures manifest as corrosion of the electronic components or as failures in the performance of the components. In addition to failures of the components themselves, films formed by conformal coatings can also fail in these aggressive conditions due to chemical degradation that can ultimately result in loss of electrical insulating or protective properties.

[0004]

[04] In addition to environmental failures, designers of electronic devices and PCBAs are constrained by creep and clearance design requirements that specify the spacing between electronic components during PCBA design. As modern applications demand higher power output in the same device footprint, or smaller size of existing designs, electrically insulating coatings can provide a dielectric barrier between electronic components and reduce the required creep and clearance distances.

[0005]

[05] As a result, durable, electrically insulating coatings have become a more common form of protection for such devices. Application of traditional coatings requires masking of certain parts to ensure they do not impede the flow of current through connectors, test points, or ground contacts. This process is expensive and time consuming, which has a detrimental effect on the overall electronics manufacturing process.

[0006]

[06] Conventional conformal coatings aim to improve their durability by increasing their mechanical strength. Furthermore, conventional conformal coatings rely on highly cross-linked networks that cannot be easily deformed. This results in hard and rigid films that require compromises during the electronics manufacturing process (e.g., masking or selective coating around certain components). Furthermore, some conformal coatings are formulated using coating compositions that contain volatile organic solvents due to the advantageous properties of these solvents as diluents and carriers. However, these volatile solvents are typically flammable and harmful to both the environment and the operators of the coating application equipment.

[0007]

[07] Thus, there is a need for conformal coatings using coating compositions that do not contain high volatile organic compound ("VOC") content to protect electronic devices. These coatings must comply with the limits set by REACH in the EU and the Blue-Sky Initiative in China, as well as other regulatory bodies at national and local levels. For example, in China, GB30981-2020 sets standards for the acceptable VOC content of industrial protective coatings, with a limit of 650 grams per liter (g / L) or less for solvent-based "varnish"-type "electrical and electronic product coatings." Furthermore, the voluntary standard GB / T38597-2020 recommends an even lower limit of 480 g / L or less for engineering machinery. It is presumed that other regions, including North America, Europe, and other parts of Asia, will adopt similar, if not more restrictive, limits.

[0008]

[08] There is also a need for methods and uses of such low VOC coatings that allow for the protection of electronic devices from contaminants, such as solid particulates including dust, dirt, and metal shavings, and liquids, such as body fluids including water and sweat. Further, there is a need for conformal coatings made from such materials that can be applied without the need to mask components prior to coating, so that an entire printed circuit board can be covered without inhibiting the functionality of the device. Summary of the Invention [Problem to be solved by the invention]

[0009]

[09] The coating compositions of the present disclosure and deformable, low VOC conformal coatings made therefrom are directed to overcoming one or more of the above problems and / or other problems of the prior art. [Means for solving the problem]

[0010] In view of the above, a low VOC composition for protecting a substrate from at least one undesirable contaminant is disclosed. In one embodiment, the composition of the present disclosure comprises at least one film-forming component comprising a water-based carrier and at least one additive, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g The resin comprises a resin present in an amount sufficient and configured to form a conformal film having a

[0011] Also disclosed is a method of making a low VOC composition for protecting a substrate against at least one undesirable contaminant. In one embodiment, the method includes providing a film-forming component with a water-based carrier and at least one additive, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g The resin comprises a resin present in an amount sufficient and configured to form a conformal film having a

[0012]

[0012] Also, the present invention provides a composition having a low or no VOC content and a glass transition temperature (T g Disclosed is a method of coating an electronic device with a conformal coating comprising a coating composition comprising a film former in a water-based carrier having ...

[0013] Also disclosed is a low VOC coating configured to protect a substrate from undesirable contaminants. In one embodiment, the coating is formed on a substrate by using a low VOC composition comprising at least one film-forming component with a water-based carrier and at least one additive. In one embodiment, the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g The resin comprises a resin present in an amount sufficient and configured to form a conformal film having a

[0014] Further disclosed are articles or devices, e.g., electronic devices, comprising the conformal coatings described herein, and methods of applying such coatings. In one embodiment, an electronic device is described comprising a conformal coating that is deformable and electrically insulating. The conformal coating is formulated with water as the evaporative carrier medium. In such an embodiment, the film former has a glass transition temperature (T g ), the film former being deformable and electrically insulating at room temperature.

[0015] In one embodiment, a substrate is disclosed comprising a coating made from the described composition. The substrate comprises a coating comprising a low VOC composition comprising at least one film-forming component comprising a water-based carrier and at least one additive. The at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to the substrate at room temperature. g The resin comprises a resin present in an amount sufficient and configured to form a conformal film having a DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016]

[0016] As used herein, "conformal coating" refers to a film that continuously follows the contours of the substrate to which it is applied, such as a printed circuit board or a component thereof, without discontinuities or openings. The conformal coatings described herein protect substrates, such as electronic circuits, against environmental and liquid or particulate matter, including water, sweat, or other moisture, dirt, dust, conductive metal particles, metal shavings, and other conductive particulate matter and chemicals.

[0017] As used herein, "coating composition" refers to the material in a liquid state that is applied onto a substrate, such as a printed circuit board or component thereof, during a coating application process.

[0018]

[0018] As used herein, "water-based" coating compositions refer to formulations comprised of water-based resins or compounds, additives, and fillers. Water-based resins or compounds refer to resins or compounds having water as the evaporative carrier medium, along with other organic solvents. These resins or compounds are immiscible or insoluble in water and form emulsions or dispersions when mixed with water. Thus, as used herein, "water-based" describes compositions having water as the primary carrier medium.

[0019] As used herein, "coalescing agent" refers to an organic compound that aids in the coalescence of particles. In polymer emulsions or dispersions, the formation of a continuous film requires the coalescence of the particles after application to a substrate. For example, in the case of latex emulsions, coalescing agents can aid in the coalescence of the latex particles into a continuous film. Non-limiting examples of such coalescing agents include benzoates, glycol ethers, and alcohol esters.

[0020] As used herein, "film former" refers to a material capable of forming a coherent, continuous film after application to a solid surface.

[0021] As used herein, "gel" or "gel state" refers to a material or composite of materials that forms an internal network due to either chemical crosslinks and / or physical associations between the components. Gel coatings exhibit non-Newtonian, viscoelastic, viscoplastic and / or elastoviscoplastic properties.

[0021]

[0022] As used herein, "deform" or "deformability" refers to the ability of a material to distort (e.g., stretch, bend, etc.) under compressive, tensile, or shear stresses typically encountered during the assembly of an electronic device or under the temperature ranges typically found during the manufacture and use of an electronic device.

[0022]

[0023] As used herein, "flow" or "fluidity" refers to the ability of a material to behave like a fluid, undergoing a constant rate of shear deformation under the application of a shear stress.

[0024] As used herein, "non-Newtonian fluid" or forms thereof means a fluid that does not follow Newton's law of viscosity (e.g., a fluid whose viscosity is variable based on an applied stress or force). The resulting coating exhibits non-Newtonian behavior, which is explained by the existence of a non-linear relationship between shear stress and shear rate or a yield stress in the coating. Non-Newtonian fluids include single-phase or multi-phase fluids that exhibit non-Newtonian behavior. It may also include single or multiple components. Non-Newtonian fluids are sometimes referred to as complex fluids. In one embodiment, the non-Newtonian fluid is viscoelastic.

[0023]

[0025] As used herein, "viscoelastic" refers to a material that exhibits both viscous and elastic properties when subjected to deformation (i.e., the material exhibits both energy storage and energy dissipation during cyclic / cyclic oscillatory shear deformation). This is typically reported in terms of non-zero measurable values ​​of both the storage modulus G' and the loss modulus G".

[0024]

[0026] As used herein, "viscoplastic" refers to the inelastic behavior of a material, which undergoes irrecoverable deformation when a critical load level (known as the yield stress) is reached. The main difference between viscoplastic and viscoelastic materials is the presence of a yield stress. Viscoplastic materials have a yield stress below which they will not flow, while viscoelastic materials will deform and flow under the application of any finite shear stress.

[0025]

[0027] As used herein, "elastoviscoplastic" refers to a broad class of materials, such as the conformal coatings described in this patent, that exhibit elastic, viscous, and plastic response properties under various levels of applied shear stress or strain. Below a critical stress, often referred to as the yield stress, the material does not undergo steady flow, but undergoes a transient deformation, where some strain accumulates elastically and some energy is dissipated by plastic (irreversible) deformation. Some of the initial deformation is stored elastically and some of the external work applied to the material is dissipated viscously, so that once a critical load level is reached (i.e., above the yield stress), the material begins to flow like a liquid but still exhibits viscoelastic properties (i.e., has measurable values ​​for the elastic modulus G' and the loss modulus G"). When the applied load is removed, this viscoelastic-viscoplastic response can be distinguished in a rheometer by partial (i.e., elastic) recoil or unloading, while some irreversible deformation accumulates due to the plastic nature of the material.

[0026]

[0028] As used herein, "electrical insulation" refers to the property of a material that provides resistance to electrical flow. For example, in one non-limiting embodiment, when a coating in a gel state is applied to an active component under bias, the coating provides an electrical resistance of greater than 1 kiloohm (kΩ), or a breakdown voltage of greater than 1.5 kilovolts per mil (kV / mil).

[0027]

[0029] As used herein, "glass transition temperature" refers to g refers to the temperature at which an amorphous polymer changes from a hard or glassy state to a soft or rubbery state, or vice versa. For water-based resins, a specific T gis the T of the final film formed when the water evaporates. g Refers to...

[0028]

[0030] As used herein, "minimum film formation temperature," denoted as MFFT, refers to the lowest temperature at which an aqueous polymer dispersion or emulsion can coalesce into a thin film when applied onto a substrate.

[0029]

[0031] As used herein, "crosslinking" includes the joining of two or more polymer chains by chemical or physical association. "Self-crosslinking resin" refers to an air-curing system that is supplied as a one-component system and does not require the addition of an external crosslinking agent prior to application. The crosslinking reaction can be triggered or initiated by different factors. Non-limiting examples of such factors include evaporation of water, a change in pH, e.g. a dramatic decrease in pH, exposure to UV radiation, and combinations thereof.

[0030]

[0032] As used herein, "volatile organic compounds" or "VOCs" are compounds with low water solubility and high vapor pressure. Various governments, regulatory agencies, and private organizations around the world have developed more specific definitions of VOCs. For example, the WHO defines VOCs as compounds with a boiling point below 250°C measured at a standard atmospheric pressure of 101.3 kilopascals (kPa). In the United States, the United States Environmental Protection Agency (US EPA) defined VOCs as any carbon compound other than carbon monoxide, carbon dioxide, carbonic acid, metal carbides or carbonates, and ammonium carbonate that participates in atmospheric photochemical reactions. In China, VOCs are defined as organic compounds with a vapor pressure of 0.01 kPa or more at room temperature (20°C) or organic chemicals that are susceptible to photoreaction.

[0031]

[0033] As used herein, "low VOC coating" refers to a coating formed from a composition having a VOC content of 300 g / L or less. Definitions of VOC vary from country to country, and even sometimes within regions within a country. As used herein, "low VOC" ranges from no VOC content (i.e., 0 g / L) to less than 300 g / L.

[0032]

[0034] As used herein, "contaminants" refers to undesirable liquids, solids, gases, or combinations thereof. In one embodiment, contaminants may include corrosive gases that create a corrosive environment, or solid particulates that may cause defects in the coating. In another embodiment, contaminants may include water, sweat, or other moisture, dirt, dust, conductive metal particles, metal shavings, and other conductive particulate matter and chemicals, and combinations thereof.

[0033]

[0035] As used herein, "REACH" (Registration, Evaluation, Authorisation and Restriction of Chemicals) is a European Union regulation adopted to improve the protection of human health and the environment from risks that may be posed by chemicals, which came into force on June 1, 2007. It also encourages alternative methods of hazard assessment of substances in order to reduce the number of tests on animals.

[0034]

[0036] As used herein, the "Blue-Sky Initiative" in China is a three-year action plan for cleaner air issued by the State Council of China in June 2018, which is a comprehensive strategy to improve air quality through actions across all key sectors. The key objectives of this action plan are to reduce emissions of major air pollutants and greenhouse gases, and to reduce the number of days with high air pollution.

[0035]

[0037] The present disclosure includes a composition for forming a conformal coating, the conformal coating composition having low or no volatile organic compound (VOC) content. The conformal coating composition is water-based. The low-VOC composition includes at least one film-forming component. The film-forming component includes a water-based carrier, and the low-VOC composition further includes at least one additive. The at least one film-forming component includes a resin present in an amount and configured to form a conformal film or coating when applied to a substrate. The conformal coating protects the substrate from at least one undesirable contaminant.

[0036]

[0038] The water-based conformal coating composition includes a water-based resin, such as an acrylic resin, a styrene-acrylic resin, a silicone, a polyurethane, a styrene-butadiene or an acrylonitrile-butadiene, and combinations thereof. In one embodiment, the water-based resin is specifically selected from those having a glass transition temperature (T g ) is selected to be less than 25° C. This results in a soft film that forms at room temperature after evaporation of the water without the need for volatile organic solvents. In one embodiment, the water-based resin has a glass transition temperature (T g In another embodiment, the glass transition temperature of the resin is in the range of -60°C to less than 25°C.

[0037]

[0039] The water-based carrier comprises water. In one embodiment, the at least one film-forming component comprising the water-based carrier comprises an aqueous emulsion or dispersion. The aqueous emulsion or dispersion may comprise water in an amount ranging from 50 to 70% by weight of the total emulsion or dispersion.

[0038]

[0040] In one embodiment, the aqueous emulsion or dispersion contains resin in an amount ranging from 30-50% by weight of the total emulsion or dispersion.

[0041] In one embodiment, the composition comprising the water-based carrier does not contain any volatile organic solvent and is VOC-free. In one embodiment, the composition has a volatile organic content of 100 g / L or less. In another embodiment, the composition has a volatile organic content of 300 g / L or less.

[0039]

[0042] In one embodiment, the conformal film is deformable and electrically insulating when applied onto a substrate. When the coating composition is applied to an electrical device, the mechanical properties exhibited by the composition of the present disclosure are designed such that application of the coating onto connector pins does not adversely affect the electrical contact resistance between the pins. This may include a negligible change in the insertion force required to mate the connector. In order to make connections through the coating, the coating must be designed to have sufficient ductility in the normal, tensile, and compressive directions and to exhibit elastic-viscoplastic flow properties. The coating may be designed to exhibit a pencil hardness of less than 6B. The storage and loss moduli of the coating in the shear, tensile, or compressive directions are greater than 10 at 25° C. when measured at frequencies of 1 to 100 radians per second (rad / s). 6 The coating may have a thermal conductivity of less than 10 Pa when subjected to stress from 1 to 100 rad / s at 25° C. in the shear, compression, or tension directions. 4 It can yield at a yield stress of less than Pa.

[0040]

[0043] Such a low T g (e.g. below 25°C) may suffer from excessive tackiness, which is due to the low T g Resin with higher T g This can be reduced by blending with additional resins having higher T g The resin has low T g It may be of the same or different chemistry as the resin. gResin choices include alkyds, vinyl acrylics, and vinyl acetate ethylene copolymers. Alternatively, blends with self-crosslinking resins may also reduce the tackiness of the final coating. These modifications are made without loss of the deformability of the coating composition. In some embodiments, the coating composition may be non-Newtonian and conformable before and while applied onto a substrate.

[0041]

[0044] The resins described herein have a T g The polymers include those having high T g In the case of resins, representative non-limiting examples include alkyds, vinyl acrylic resins, and vinyl acetate ethylene copolymers. g Resin coalescence can be improved by adding up to 300 g / L of coalescing solvent to the conformal coating composition.

[0042]

[0045] The water-based resins described herein include polymer emulsions or dispersions. Suitable polymers are thermoplastic resins having a high molecular weight of 50,000 Daltons or greater. The polymers have a T of 25° C. or less. g The compound is synthesized to have the following structure:

[0043]

[0046] A variety of polymer chemistries can be used, including acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, alkyds, vinyl-acrylics, vinyl acetate ethylene copolymers, and mixtures or copolymers thereof. In some embodiments, the polymer emulsions and dispersions can be prepared via polymerization reactions of monomers, oligomers, or combinations thereof. Non-limiting examples of monomers that may be used to prepare the waterborne resin include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isobutyl acrylate, lauryl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate and ethoxypropyl acrylate, ethylene, butadiene, propene, butene, isobutene, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, hydroxypropyl acrylate, hydroxybutyl acrylate, styrene, alpha-methylstyrene, acrylonitrile, allyl methacrylate, acetoacetylethyl methacrylate (AAEM), diacetone acrylamide (diacetone acrylamide), methyl methacrylate, ethyl methacrylate (ETHAEM), methyl methacrylate (MMMA), ethyl methacrylate (ETHAEM ... crylamide (DAAM), dimethylamino methacrylate, diethylamino methacrylate, silane-containing monomers, diol-containing monomers, diisocyanate monomers and mixtures thereof.

[0044]

[0047] In certain embodiments, the polymer emulsions and dispersions can be prepared via a single-stage or multi-stage process. The multi-stage process produces polymers of different T, known as "core-shell particles." gPolymer emulsions and dispersions prepared using single or multi-stage processes can be made using continuously varying addition of two or more monomers, or using discrete sequential addition of two or more monomers or mixtures of monomers.

[0045]

[0048] In certain embodiments, the polymer has a single T g The polymer resin may not necessarily exhibit a sharp inflection point corresponding to the change in composition during polymerization. A "gradient" polymer resin is an example of this phenomenon, where there is a change in composition during polymerization. For such polymer resins, the monomers are selected such that the deformability of the resin still meets the requirements outlined in this invention.

[0046]

[0049] In certain embodiments, crosslinkable groups and other additives may be added as part of the monomer mixture or may be added post-added as additives. Crosslinking can occur by heating, UV exposure, evaporation of water, dramatically lowering the pH, or in two-component systems after addition of a crosslinker prior to application.

[0047]

[0050] During polymerization, surfactants may be used.Surfactants may be selected from nonionic surfactants, anionic surfactants, cationic surfactants, and combinations thereof.Non-limiting examples of surfactants that may be used herein may be selected from non-reactive surfactants or reactive surfactants.Non-limiting examples of such non-reactive surfactants include polyoxyethylene alkyl ethers and polyoxyethylene styrenated phenyl ethers.Non-limiting examples of such reactive surfactants include surfactants that copolymerize with monomers during polymerization reaction.

[0048]

[0051] In certain embodiments, the emulsions or dispersions may be prepared by emulsion polymerization of monomers, oligomers, prepolymers, or mixtures thereof.

[0052] In certain embodiments, the emulsion or dispersion may be prepared by mechanical emulsification. Non-limiting examples of mechanical emulsification are high shear mixing or high pressure homogenization. In some embodiments, a high shear mixer or high pressure homogenizer may be used to form an emulsion from preformed polymers, surfactants, carrier fluids (such as water), and combinations thereof. Additionally, additives or low T g Resins can be added to already formed emulsions to improve their durability or deformability. In some embodiments, emulsions or dispersions can be prepared by making a dispersion of a polymer with water and a surfactant or other dispersing agent, the polymer being synthesized by other methods including bulk and solution polymerization.

[0049]

[0053] In one embodiment, the conformal coating composition can be prepared by low shear mixing of the resins in the desired ratios until a homogenous mixture is obtained. Typical ratios for blending are 50-100% by weight of low T g Resins, which may be one or a combination of chemistries, include acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene. The coating composition may be applied onto the desired substrate and then dried at room temperature. The addition of alcohols, such as methanol or isopropanol, up to 50 g / L, may also increase the drying rate. The use of drying cabinets or other methods of introducing airflow to reduce ambient humidity may also be used to increase the drying rate. Heating in an oven, although not required, may also be used to increase the drying rate. Additional protection of the PCBA may be achieved by underfilling components such as integrated circuits and ball grid arrays. The drying rate of coatings applied under components may be accelerated by using heat. In the case of printed circuit boards with connector pins, these pins do not need to be masked and the coating may be applied directly over them, reducing production time and costs. Alternative compositions that may achieve the same results are also available with low T gResins may be included and crosslinking agents are introduced. In one embodiment, these compositions may be applied as two-part systems where the pot life of the mixture is limited. In one embodiment, crosslinking occurs by UV irradiation or heating.

[0050]

[0054] In one embodiment, the coating composition may be made with one or more additives to further improve coating properties. Such additives include fillers, plasticizers, initiators, defoamers, surfactants, antioxidants, hydrophobizing agents, biocides, leveling agents, substrate wetting agents, crosslinkers, dyes, pigments, dispersants, passivators, adhesion promoters, coalescing agents or solvents, rheology modifiers, UV absorbers or stabilizers, and corrosion inhibitors. Non-limiting examples of such additives can be found in PCT / US2021 / 061909, filed December 3, 2021, which is incorporated herein by reference in its entirety.

[0051]

[0055] In one embodiment, the at least one additive is present in the coating composition in an amount ranging from 0.001% to 40% by weight.

[0056] In one embodiment, the use of fillers such as fumed silica and fumed alumina may also be used to reduce the tackiness of the coating. Examples of such fillers may include functionalized fumed silica, non-functionalized fumed silica, precipitated silica, silica nanoparticles, alumina nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

[0052]

[0057] In one embodiment, the plasticizer is added up to 40% in the total composition to further soften the film. In another embodiment, the plasticizer is added up to 25%. The plasticizer may be selected from polymeric plasticizers, benzoate plasticizers, and phthalate plasticizers as additives in the coating composition of the present disclosure. Examples of benzoate plasticizers may include diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof. Examples of polymeric plasticizers may include poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, bio-based alkyds, and combinations thereof. In one embodiment, the plasticizer may include hydrogenated alicyclic hydrocarbon resins, trimellitates, high molecular weight orthophthalates, silicone oils, octyl epoxy esters, or hydrotreated light naphthenic petroleum distillates, and combinations thereof.

[0053]

[0058] In one embodiment, the additive may include an initiator. Examples of such initiators may include di- or multi-functional alpha-hydroxyketones, acylphosphine oxides, benzoyl formates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

[0054]

[0059] In one embodiment, the additive may include an antifoaming agent. Examples of such antifoaming agents may include silicone oils, mineral oils, vegetable oils, polar oils, molecular antifoam agents, hydrophobic nanoparticles, emulsifiers, solvents, and combinations thereof.

[0055]

[0060] In one embodiment, the additive may include a molecular defoamer, such as a gemini surfactant having a dimeric structure composed of two hydrophobic chains and two hydrophilic heads linked by a spacer at or near the head groups. In addition to the chemistries listed above, waterborne epoxy systems may be designed such that the films formed are deformable by reducing the degree of crosslinking within the system.

[0056]

[0061] In one embodiment, the additives may include hydrophobizing agents including paraffin wax emulsions, modified paraffin waxes, paraffin / polyethylene wax emulsions, silicone resins, and combinations thereof.

[0057]

[0062] In one embodiment, the additive may include a biocide agent including isothiazolinones, formaldehyde-releasing biocides (FA-R), carbamate-containing fungicides, and combinations thereof.

[0058]

[0063] In one embodiment, the additives may include rheology modifiers including hydrophobically modified ethoxylated urethane (HEUR) type thickeners, alkali swellable emulsions, acrylic copolymers, and combinations thereof.

[0059]

[0064] In one embodiment, the additive may include a leveling agent including modified silicones, fluorosurfactants, and combinations thereof. In other embodiments, the leveling agent may include silicones, liquid polyacrylates, ionic surfactants, non-ionic surfactants, and combinations thereof.

[0060]

[0065] In one embodiment, the additive may include substrate wetting agents including siloxanes, multifunctional surfactants, polyglycol ethers, modified polyglycol ethers, and combinations thereof.

[0061]

[0066] In one embodiment, the additive may include dyes including stilbene compounds, distyryl biphenyl derivatives, benzoxazoles, and combinations thereof. In one embodiment, the additive may include crosslinkers. The crosslinkers may include zinc ammonium carbonate solution, carbodiimide crosslinkers, melamine crosslinkers, aziridine crosslinkers, mono- or multi-functional aliphatic glycerol polyglycidyl ether-based crosslinkers, mono- or multi-functional aliphatic epoxies, ethylene glycol diglycidyl ether, oxazoline reactive polymers, polyols, polyisocyanates, methylacrylamide, dihydrazide crosslinkers, organofunctional silanes, metal complexes, UV-vulnerable functional monomers, and combinations thereof.

[0062]

[0067] In one embodiment, the additive may include a pigment. The pigment may include organic or inorganic pigments and combinations thereof. In further embodiments, the organic and inorganic pigments may include color pigments and dyes including borophosphates, borosilicates, phosphates and phosphosilicates, inorganic pigments, organic pigments and pigment and dispersant dispersions, carbon black, special effect pigments, titanium dioxide, and combinations thereof. In alternative embodiments, pigments may be added to impart color or functionality including anticorrosive properties.

[0063]

[0068] In one embodiment, the additive may include a dispersant. The dispersant may include fatty acid modified polyesters, sodium salts of acrylic polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, and combinations thereof.

[0064]

[0069] In one embodiment, the additive may include an adhesion promoter. The adhesion promoter may include silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

[0065]

[0070] In one embodiment, the additives may include coalescing aids including glycol ethers, ester alcohols, and combinations thereof. In one embodiment, a high boiling point coalescing solvent with a boiling point of 250° C. or higher may be used so that the solvent evaporates slowly over time, for example over minutes, hours, or days. In this case, the coalescing solvent acts as a temporary plasticizer that may soften the film to make it deformable. Once the solvent has completely evaporated, the film hardens. This is advantageous for applications where deformability is desired for the first few days after the coating process, but in this technical field, a harder film may provide more robust protection.

[0066]

[0071] In one embodiment, the additives may include UV absorbers or stabilizers including hydroxy-phenyl-benzo-triazoles, hydroxy-phenyl-triazines, hydroxy-benzophenones, sterically hindered amines, and combinations thereof.

[0067]

[0072] In one embodiment, the additive may include corrosion inhibitors including organic acid amine complexes, zinc phosphate, and combinations thereof.

[0073] In one embodiment, the additive may include antioxidants including phenolic antioxidants, amine antioxidants, thioether antioxidants, phosphite antioxidants, lactones, and combinations thereof.

[0068]

[0074] In one embodiment, the antioxidant is a reaction product of benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, octadecyl ester; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester; isomeric C7-9-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionates. mass); 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-; benzenepropanoic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-, 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl) ester; or reaction products with phenol, 4-methyl-, dicyclopentadiene and isobutylene, and combinations thereof. In one embodiment, the amine antioxidant may be selected from benzeneamine, N-phenyl-, reaction product with 2,4,4-trimethylpentene; 1-naphthaleneamine, N-phenyl-ar-(1,1,3,3-tetramethylbutyl); 4,4'-dioctyldiphenylamine; other alkylated amines, and combinations thereof. In one embodiment, the thioether antioxidant may be selected from propanoic acid, 3-(dodecylthio)-, 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or propanoic acid, 3,3'-thiobis-, 1,1'-ditridecyl ester; and combinations thereof.In one embodiment, the phosphite antioxidant may be selected from tris(2,4-di-tert-butylphenyl)phosphite; butylidenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tetratridecylbis(phosphine); 12H-dibenzo[d,g][1,3,2]dioxaphosphocin, 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-; and combinations thereof.

[0069]

[0075] In one embodiment, the additive may include a passivation agent. Such a passivation agent may include hydrazides or triazoles selected from dodecanedioic acid, 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 1,2,4-triazole, 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide; 1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-ar-methyl-; 1H-1,2,4-triazole-1-methanamine, N,N-bis(2-ethylhexyl)-; and combinations thereof.

[0070]

[0076] In one embodiment, the additives may include rheology modifiers including sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

[0071]

[0077] In one embodiment, the additives may include adhesion promoters including chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinylsilane, silanes, and combinations thereof.

[0072]

[0078] In one embodiment, the additive may include a substrate wetting or dispersing agent. Examples of such substrate wetting or dispersing agents may include alkyl ammonium salts of polycarboxylic acids, alkyl ammonium salts of acidic polymers, salts of unsaturated polyamine amides and acidic polyesters, maleic anhydride functionalized ethylene butyl acrylate copolymers, other ionic or non-ionic surfactants, and combinations thereof.

[0073]

[0079] In one embodiment, the additives may include tackifiers including hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

[0080] In one embodiment, a method of making a low VOC composition for protecting a substrate against at least one undesirable contaminant may include providing a film-forming component and at least one additive. The film-forming component may include a water-based carrier. The at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g The resin may include a resin present in an amount and configured sufficient to form a conformal film having a

[0074]

[0081] In one embodiment, the step of providing a film-forming component for the method of making a low-VOC composition may include at least one polymerization step. The at least one polymerization step may include reacting at least one monomer, oligomer, or prepolymer to produce a film-forming polymer resin that can be dispersed or suspended in a water-based carrier with at least one additive to form the low-VOC composition. The monomer, oligomer, or prepolymer may include one or more functional groups that can participate in a polymerization reaction.

[0075]

[0082] In one embodiment, the polymerization step may proceed by addition or polycondensation or a combination thereof.

[0083] In one embodiment, the polymerization step may be carried out after at least one monomer, oligomer, or prepolymer is dispersed or suspended in a water-based carrier. The polymerization step produces a reaction product, which is then dispersed or suspended in the water-based carrier.

[0076]

[0084] In one embodiment, the method of making the conformal coating composition may produce one or more of the following by-products: water, ammonia, and compounds formed by condensation reactions.

[0077]

[0085] In one embodiment, at least one additive can be added to the polymerization reaction or can be added to the reaction product afterwards.The addition of monomer, oligomer or prepolymer can be carried out in a single stage or multi-stage process.For example, the addition of monomer, oligomer or prepolymer can be carried out using the continuous variable addition of two or more monomers, or using the discrete sequential addition of two or more monomers or mixtures of monomers.

[0078]

[0086] In one embodiment, a method of coating a substrate may include coating the substrate with a low VOC conformal coating composition. The conformal coating composition may include at least one film-forming component with a water-based carrier and at least one additive. The at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g The resin may include a resin present in an amount and configured sufficient to form a conformal film having a

[0079]

[0087] The coating can be applied onto the substrate using a number of techniques, non-limiting examples of which can include atomized or non-atomized spray coating, needle dispensing, dipping, jetting, blade coating, brushing, inkjet printing, crosslinking with UV radiation, crosslinking with heat, crosslinking using humidity, or combinations thereof.

[0080]

[0088] In one embodiment, the coating composition may exist as a multi-component system, each having a subset of components, and each of the multi-component system may be applied to the substrate sequentially or simultaneously to form a conformal coating.

[0081]

[0089] In one embodiment, once the coating composition is applied onto a substrate, there may be an intermediate stage where the carrier medium evaporates, leaving behind the coating. In some embodiments, the coating composition at this intermediate stage may have a residual amount of evaporative carrier medium. In some embodiments, the evaporative carrier medium may be water, a coalescing solvent, an alcohol, a pH neutralizer, or a combination thereof.

[0082]

[0090] In one embodiment, the substrate is an electronic device. The coating may cover the male, female, or both components of a connector in the electronic device without adversely affecting the electrical properties of the printed circuit board.

[0083]

[0091] In one embodiment, the coating may have a lubricating effect and may reduce the force required to insert and mate the connector when applied onto the substrate. In another embodiment, the substrate is partially coated or entirely coated. Furthermore, when the coating is applied onto the printed circuit board, the coating may be deposited on different components of the printed circuit board based on the desired environmental protection.

[0084]

[0092] In one embodiment, the coating can be deposited on a substrate to achieve a film thickness ranging from 25 nanometers (nm) to 500 micrometers (μm). When the coating composition is applied onto a substrate to form a conformal coating, at least one component in the coating composition can evaporate, rendering the coating deformable during evaporation and non-deformable after evaporation. In one embodiment, one of the components in the coating can crosslink, rendering the coating deformable during crosslinking and non-deformable after crosslinking.

[0085]

[0093] In one embodiment, when applied as a coating, the conformal coating may be in the range of thickness from 25 nm to 500 μm, e.g., 50 nm to 100 μm, e.g., 1 μm to 200 μm, e.g., 10 μm to 500 μm. In some embodiments, the coating may conform to substrate morphology having length scales less than 1 μm, e.g., less than 100 nm to 1 μm, to protect the substrate from undesired contaminants. Examples of undesired contaminants may include, but are not limited to, liquids, particles, corrosive environments, and combinations thereof. In one embodiment, the undesired contaminants may be any one of water, sweat, or other moisture, dirt, dust, conductive metal particles, metal shavings, and other conductive particulate matter and chemicals, and combinations thereof.

[0086]

[0094] Coating thickness can be measured by non-destructive optical techniques such as ellipsometry, spectroscopic reflectance techniques such as interferometry, and confocal microscopy. Non-limiting examples of such non-destructive methods for measuring coating thickness include SEM. Conventional coatings such as conformal and vacuum coatings are typically much thicker than the coating thickness of the present disclosure. For example, conventional coatings range in thickness up to hundreds of microns, which can inhibit both radio frequency and Wi-Fi transmission of electronic devices and can even act as thermal insulators. The thinner thickness range of the gel-like coating does not adversely affect the functionality of the electronic device and can have negligible thermal shock to the device. A non-limiting example of a functioning electronic device is a fully assembled printed circuit board. A fully assembled printed circuit board with a gel-like coating exhibits normal radio frequency performance, normal thermal properties, and other normal functionality.

[0087] Measurement techniques

[0095] After application of the coating to the electronic device, various properties can be measured in the following manner.

[0088]

[0096] The hydrophobicity or hydrophilicity of a coating can be measured by observing the contact angle that a drop of water makes on the surface of the coating. The oleophobicity or oleophilicity of a coating can be measured by observing the contact angle that a drop of hexadecane makes on the surface of the coating.

[0089]

[0097] The electrical insulating properties of a coating can also be determined by measuring the voltage resistance on a coated circuit board. A continuously increasing voltage can be applied to the coated circuit board and the voltage at which current arcs through the air can be determined. This voltage is a measure of the effectiveness of the coating.

[0090]

[0098] The electrical insulating properties of a coating can also be determined by measuring the material electrical properties of the coating, such as the loss tangent or dielectric constant, using a network analyzer.

[0091]

[0099] The non-Newtonian, viscoelastic, viscoplastic, and elastoviscoplastic properties of the coating can be measured by looking at various properties. The response of the coating to an applied stress or strain can be measured by testing the deformation of the coating using a rheometer. Viscoelastic modulus can be measured using a Small Angle Oscillatory Stress sweep, and yield stress and high shear viscosity can be measured using a stress sweep. The degree of deformation can also be measured by quantifying hardness, elastic modulus, tack, strain at break, creep, and ductility in the tensile, compressive, and shear directions.

[0092]

[0100] The features and advantages of the compositions, coatings, and methods disclosed herein are illustrated by the following examples, which should not be construed in any way as limiting the scope of the disclosure. EXAMPLES

[0093]

[0101] The conformal coating compositions were prepared by low shear mixing of the resins in the desired ratios until a homogeneous mixture was obtained. The coating compositions were applied onto the desired substrate by spray coating or blade coating, unless otherwise specified, and then allowed to dry under ambient conditions. The invention is illustrated by the following examples.

[0094] Example 1

[0102] In this example, 10 g of acrylic emulsion (T g The mixture was placed in a beaker at -42°C, 50% solids, and pH: 7.7-8.2. Under low shear mixing, 0.005g of adhesion promoter and 0.005g of UV dye were added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7-8.2.

[0095] Example 2

[0103] In this example, 10 g of acrylic emulsion (T gA mixture of 0.035g of bactericide and 0.25g of fungicide, and 0.005g of UV dye was added under low shear mixing. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH between 7.7 and 8.2.

[0096] Example 3

[0104] In this example, 8 g of acrylic emulsion (T g : -42℃, solids content 50%, pH: 7.7~8.2) and 2g of self-crosslinking styrene acrylic emulsion (T g The mixture (temperature: 23°C, solids content: 43% by weight, pH: 7.7-8.2) was placed in a beaker. Under low shear mixing, 0.005 g of UV dye was added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7-8.2.

[0097] Example 4

[0105] In this example, 9 g of self-crosslinking styrene acrylic emulsion (minimum film formation temperature: 8-12 °C, 48% solids, pH: 8.5-9.0) was placed in a beaker. Under low shear mixing, 2 g deionized water, 0.05 g substrate wetting agent, 0.005 g UV dye, 0.04 g bactericide, 0.1 fungicide, 0.1 g surfactant and 1 g plasticizer were added. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH at 8.5-9.0.

[0098] Example 5

[0106] In this example, 9 g of self-crosslinking styrene acrylic emulsion (minimum film formation temperature: 8-12 °C, solids content 48 wt%, pH: 8.5-9.0) was placed in a beaker. Under low shear mixing, 1.24 g of deionized water, 0.005 g of UV dye, 0.25 g of coalescing solvent, 0.05 g of defoamer, and 1 g of plasticizer were added. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH at 8.5-9.0.

[0099] Example 6

[0107] In this example, 9 g of acrylic emulsion (T g A mixture of 1000 ml of 100% ethanol (pH: 7°C, 57 wt% solids, pH: 7.5-9.5) was placed in a beaker. Under low shear mixing, 1 g of coalescing solvent (boiling point: 274°C), 3 g of deionized water, and 0.005 g of UV dye were added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.5-9.5.

[0100] Example 7

[0108] In this example, 8.5 g of acrylic emulsion (T g A mixture of 2.25 g deionized water, 0.05 g substrate wetting agent, 0.005 g UV dye, 0.04 g bactericide, 0.1 g fungicide, and 1.5 g plasticizer was added under low shear mixing. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH between 7.5 and 9.5.

[0101] Example 8

[0109] In this example, 9.5 g of acrylic emulsion (T g A mixture of 0.5g of hydrophobic fumed silica dispersion (pre-dispersed in water at 20% solids by weight) and 0.005g of UV dye was added under low shear mixing. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7 and 8.2.

[0102] Example 9

[0110] In this example, 8.5 g of acrylic emulsion (T g A mixture of 1.5g of deionized water, 0.05g of substrate wetting agent, 0.005g of UV dye, 0.015g of leveling agent, and 1.5g of plasticizer was added under low shear mixing. The pH was monitored throughout the mixing process and neutralizing agents were added to maintain the pH between 7.5 and 9.5.

[0103] Example 10

[0111] In this example, 8.5 g of acrylic emulsion (T g A mixture of 2.25 g of deionized water, 0.05 g of substrate wetting agent, 0.005 g of UV dye, 0.02 g of rheology modifier, and 1.5 g of plasticizer was added under low shear mixing. The pH was monitored throughout the mixing process and neutralizing agents were added to maintain the pH between 7.5 and 9.5.

[0104] Example 11

[0112] In this example, 9 g of acrylic emulsion (T g : -42℃, solid content 50% by weight, pH: 7.7 to 8.2) and 1g of silicone emulsion (T g : -41 °C, 45 wt%, pH: 11) was placed in a beaker. Under low shear mixing, 0.005 g of UV dye was added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7 and 8.2.

[0105] Example 12

[0113] In this example, 9.6 g of acrylic emulsion (T g A mixture of 0.4g of paraffin-based wax emulsion (50% solids by weight, pH: 7.7-8.2) and 0.4g of paraffin-based wax emulsion (50% solids by weight) was placed in a beaker. Under low shear mixing, 0.005g of UV dye was added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7-8.2.

[0106] Example 13

[0114] In this example, 10 g of acrylic emulsion (T g A mixture of 0.1 g of UV dye (pre-dissolved in solution at 15 wt% solids) and 0.1 g of crosslinker (pre-dissolved in solution at 15 wt% solids) was placed in a beaker. Under low shear mixing, 0.005 g of UV dye was added. The pH was monitored throughout the mixing process and neutralizing agent was added to maintain the pH between 7.7 and 8.2. [Industrial Applicability]

[0107]

[0115] The present disclosure describes conformal coatings formulated as low-VOC or VOC-free water-based coatings designed to protect electronic devices or substrates such as printed circuit board assemblies (PCBA) from undesirable contaminants. In particular, the present disclosure is useful for manufacturers seeking protection against moisture with stringent VOC requirements, or manufacturers who wish to reduce the need for fume emissions and flammable storage will benefit from the present invention. This includes electrical insulation for printed circuit board manufacturers, and general protection against moisture for non-electrical devices / components where exposure to water may result in water-induced damage such as corrosion, discoloration, or marring. In addition to performance benefits, low-VOC or VOC-free coatings may reduce overall manufacturing costs and may also reduce the environmental impact of using conformal coatings.

[0108]

[0116] Thus, in one embodiment, the utility of the present invention is to allow for post-assembly modifications to the PCBA while protecting the circuit board from exposure to water or other adverse environmental elements during the manufacturing process or during product maintenance. These modifications may include functional board connections through the conformal coating of the present disclosure, or rework of faulty board components. The conformal coating of the present disclosure is also advantageous in accommodating thermal expansion or contraction of the PCBA without contributing additional mechanical stresses.

[0109]

[0117] In another embodiment, the surface may comprise a metal and the undesirable environment is corrosive and aqueous, such as condensation, tap water, sweat, sebum, salt water, carbonated drinks, coffee, coolants, or antifreeze. In one embodiment, the surface may comprise a metal that exhibits galvanic corrosion and the undesirable environment causes galvanic corrosion. More generally, the surface may comprise any metal that may undergo oxidation or other adverse chemical reactions due to a corrosive environment.

[0110]

[0118] Conformal coatings may exhibit viscoelastic, viscoplastic, or elastic-viscoplastic properties once applied and the water evaporates to form a continuous film.

[0119] The conformal coating can also have a thickness ranging from 25 nm to 500 μm when applied on a variety of surfaces.

[0111]

[0120] Conformal coatings can conform to features on length scales less than 25 nm and provide protection from corrosive environments.

[0121] In one embodiment, the composition exhibits electrical insulation properties such that when the composition is placed between two metal contacts, it prevents electrical leakage or arcing between the metal contacts. Electrical insulation properties can also prevent the flow of electrical current from active electronics on a printed circuit board to a conductive medium or environment, or prevent electrostatic discharge from charge carriers to active electronics on a printed circuit board. In one embodiment, the coating composition can be applied onto an automotive part to form a conformal coating and protect against undesirable contaminants.

[0112]

[0122] Provided herein is a low VOC composition for protecting a substrate from at least one undesirable contaminant, comprising at least one film-forming component with a water-based carrier and at least one additive, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g A low VOC composition is described that includes a resin present in an amount sufficient and configured to form a conformal film having a viscosity of 100 psig (VOC) and a viscosity of 100 psig (VOC) of 100 psig (VOC).

[0113]

[0123] In one embodiment, the low VOC compositions described herein provide conformal films that are deformable and electrically insulating when applied onto a substrate.

[0124] In one embodiment, in the low VOC compositions described herein, the at least one additive comprises a filler, a plasticizer, an initiator, an antifoaming agent, a surfactant, an antioxidant, a hydrophobizing agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, an adhesion promoter, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a corrosion inhibitor.

[0114]

[0125] In one embodiment, in the low VOC compositions described herein, the at least one additive is present in the composition in an amount ranging from 0.001% to 40% by weight.

[0126] In one embodiment, the filler comprises functionalized fumed silica, non-functionalized fumed silica, precipitated silica, silica nanoparticles, alumina nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

[0115]

[0127] In one embodiment, the plasticizers include polymeric plasticizers, benzoate plasticizers, and phthalate plasticizers.

[0128] In one embodiment, the benzoate plasticizer includes diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

[0116]

[0129] In one embodiment, the polymeric plasticizer includes poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, bio-based alkyds, and combinations thereof.

[0117]

[0130] In one embodiment, the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitates, polymeric orthophthalates, silicone oils, octyl epoxy esters or hydrotreated light naphthenic petroleum distillates, and combinations thereof.

[0118]

[0131] In one embodiment, the initiator includes di- or polyfunctional alpha-hydroxyketones, acylphosphine oxides, benzoyl formates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

[0119]

[0132] In one embodiment, the antifoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular antifoam agent, hydrophobic nanoparticles, emulsifiers, solvents, and combinations thereof.

[0133] In one embodiment, the surfactant comprises a nonionic surfactant, anionic surfactant, cationic surfactant, zwitterionic surfactant, and combinations thereof.

[0120]

[0134] In one embodiment, the hydrophobizing agent includes paraffin wax emulsion, modified paraffin wax, paraffin / polyethylene wax emulsion, silicone resin, and combinations thereof.

[0121]

[0135] In one embodiment, the biocidal agents include isothiazolinones, formaldehyde-releasing biocides (FA-R), carbamate-containing fungicides, and combinations thereof.

[0136] In one embodiment, the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

[0122]

[0137] In one embodiment, the leveling agent includes silicones, liquid polyacrylates, ionic surfactants, non-ionic surfactants, fluorosurfactants, and combinations thereof.

[0123]

[0138] In one embodiment, the substrate wetting agent comprises a siloxane, a multifunctional surfactant, a polyglycol ether, a modified polyglycol ether, and combinations thereof.

[0139] In one embodiment, the dyes include stilbene compounds, distyrylbiphenyl derivatives, benzoxazoles, and combinations thereof.

[0124]

[0140] In one embodiment, the crosslinker comprises zinc ammonium carbonate solution, carbodiimide crosslinkers, melamine crosslinkers, aziridine crosslinkers, mono- or multi-functional aliphatic glycerol polyglycidyl ether based crosslinkers, mono- or multi-functional aliphatic epoxies, ethylene glycol diglycidyl ether, oxazoline reactive polymers, polyols, polyisocyanates, methylacrylamide, dihydrazide crosslinkers, organofunctional silanes, metal complexes, UV-unstable functional monomers, and combinations thereof.

[0125]

[0141] In one embodiment, pigments include colored pigments and dyes including borophosphates, borosilicates, phosphates and phosphosilicates, inorganic pigments, organic pigments and pigment and dispersant dispersions, extender pigments, carbon black, special effect pigments, titanium dioxide, and combinations thereof.

[0126]

[0142] In one embodiment, the dispersing agent comprises a fatty acid modified polyester, a sodium salt of an acrylic polymer, an ammonium salt of a hydrophobic copolymer, a modified polyacrylate, a zwitterionic surfactant, and combinations thereof.

[0127]

[0143] In one embodiment, the adhesion promoter comprises a silane, an ethylene copolymer, a hydroxyl functional copolymer, and combinations thereof.

[0144] In one embodiment, the coalescent comprises glycol ethers, ester alcohols, and combinations thereof.

[0128]

[0145] In one embodiment, the UV absorbers or stabilizers include hydroxy-phenyl-benzo-triazoles, hydroxy-phenyl-triazines, hydroxy-benzophenones, sterically hindered amines, and combinations thereof.

[0129]

[0146] In one embodiment, the corrosion inhibitor comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

[0147] In one embodiment, the antioxidants include phenolic antioxidants, amine antioxidants, thioether antioxidants, phosphite antioxidants, lactones, and combinations thereof.

[0130]

[0148] In one embodiment, the phenolic antioxidant is selected from the group consisting of benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, octadecyl ester; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester; isomeric reactants of C7-9-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionates; 1, 3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-; benzenepropanoic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-, 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl) ester; or phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutylene, and combinations thereof.

[0131]

[0149] In one embodiment, the amine antioxidant is selected from benzeneamine, N-phenyl-, reaction products with 2,4,4-trimethylpentene; 1-naphthalenamine, N-phenyl-ar-(1,1,3,3-tetramethylbutyl); 4,4'-dioctyldiphenylamine; other alkylated amines, and combinations thereof.

[0132]

[0150] In one embodiment, the thioether antioxidant is selected from propanoic acid, 3-(dodecylthio)-, 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or propanoic acid, 3,3'-thiobis-, 1,1'-ditridecyl ester; and combinations thereof.

[0133]

[0151] In one embodiment, the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylidenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tetratridecylbis(phosphine); 12H-dibenzo[d,g][1,3,2]dioxaphosphocin, 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-; and combinations thereof.

[0134]

[0152] In one embodiment, the passivation agent comprises a hydrazide or triazole selected from dodecanedioic acid, 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 1,2,4-triazole, 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide; 1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-ar-methyl-; 1H-1,2,4-triazole-1-methanamine, N,N-bis(2-ethylhexyl)-; and combinations thereof.

[0135]

[0153] In one embodiment, the rheology modifier includes sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

[0136]

[0154] In one embodiment, the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinylsilane, silanes, and combinations thereof.

[0137]

[0155] In one embodiment, substrate wetting or dispersing agents include alkyl ammonium salts of polycarboxylic acids, alkyl ammonium salts of acidic polymers, salts of unsaturated polyamine amides and acidic polyesters, maleic anhydride functionalized ethylene butyl acrylate copolymers, other ionic or non-ionic surfactants, and combinations thereof.

[0138]

[0156] In one embodiment, the tackifier comprises hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

[0157] In one embodiment, the conformal film has a thickness in the range of 25 nm to 500 μm.

[0139]

[0158] In one embodiment, at least one film-forming component that comprises a water-based carrier comprises an aqueous emulsion or dispersion.

[0159] In one embodiment, the aqueous emulsion or dispersion comprises water in an amount ranging from 50 to 70% by weight.

[0140]

[0160] In one embodiment, the aqueous emulsion or dispersion comprises the resin in an amount ranging from 30 to 50% by weight.

[0161] In one embodiment, the water-based carrier does not contain any volatile organic solvents and is VOC-free.

[0141]

[0162] In one embodiment, the resin is selected from acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

[0142]

[0163] In one embodiment, the composition has a higher T g The composition further comprises an additional resin having the formula:

[0164] In one embodiment, the additional resin has the same or different chemical properties as the first resin.

[0143]

[0165] In one embodiment, the additional resin comprises an alkyd, a vinyl acrylic resin, or a vinyl acetate ethylene copolymer.

[0166] In one embodiment, at least one film-forming component comprises a blend of the above resins and a self-crosslinking resin.

[0144]

[0167] In one embodiment, the composition comprises a plasticizer in an amount up to 40% by weight.

[0168] In one embodiment, the composition has a volatile organic content of less than or equal to 100 g / L.

[0145]

[0169] In one embodiment, the composition has no volatile organic content.

[0170] In one embodiment, the at least one undesirable contaminant includes one or more of liquids, particulates, corrosive environments, and combinations thereof.

[0146]

[0171] In one embodiment, the at least one undesirable contaminant includes water, sweat or other moisture, dirt, dust, conductive metal particles, metal shavings, and other conductive particulate matter and chemicals, and combinations thereof.

[0147]

[0172] Also provided herein is a method of making the low VOC composition described herein and summarized above for protecting a substrate against at least one undesirable contaminant, comprising the steps of providing a film-forming component comprising a water-based carrier, and combining at least one additive with said film-forming component comprising a water-based carrier, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g A method is described in which the resin is present in an amount sufficient and configured to form a conformal film having a

[0148]

[0173] In one embodiment, the step of providing the film-forming component comprises at least one polymerization step comprising reacting at least one monomer, oligomer or prepolymer to produce a film-forming polymeric resin that can be dispersed or suspended in a water-based carrier with at least one additive to form the low VOC composition.

[0149]

[0174] In one embodiment, the monomer, oligomer or prepolymer contains one or more functional groups capable of participating in a polymerization reaction.

[0175] In one embodiment, the polymerization step proceeds by addition or polycondensation or a combination thereof.

[0150]

[0176] In one embodiment, the polymerization step is carried out after at least one monomer, oligomer or prepolymer is dispersed or suspended in a water-based carrier.

[0177] In one embodiment, the polymerization step produces a reaction product which is then dispersed or suspended in a water-based carrier.

[0151]

[0178] In one embodiment, the method produces one or more of the following by-products: water, ammonia, and compounds formed by condensation reactions.

[0179] Also provided herein is a method of coating a substrate with a film comprising the low VOC composition described herein and summarized above, comprising the step of coating a substrate with a low VOC conformal coating composition comprising at least one film-forming component comprising a water-based carrier and at least one additive, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to the substrate at room temperature. g A method is described in which the resin is present in an amount sufficient and configured to form a conformal film having a

[0152]

[0180] In one embodiment, the coating is applied using one or more methods selected from misted or non-misted spray coating, needle dispensing, dipping, jetting, blade coating, brushing, inkjet printing, crosslinking with UV radiation, crosslinking with heat, crosslinking using humidity, or combinations thereof.

[0153]

[0181] In one embodiment, the coating is deformable and electrically insulating when applied onto a substrate.

[0182] Also disclosed is a coating configured to protect a substrate from undesirable contaminants, the coating comprising a low VOC composition comprising at least one film-forming component comprising a water-based carrier and at least one additive, wherein the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. g Disclosed is a coating comprising a resin present in an amount sufficient and configured to form a conformal film having a

[0154]

[0183] Also provided herein is a substrate comprising a coating, the coating comprising a low VOC composition comprising at least one film-forming component comprising a water-based carrier and at least one additive, the at least one film-forming component having a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature. gDisclosed is a substrate comprising a resin present in an amount sufficient and configured to form a conformal film having a

[0155]

[0184] In one embodiment, the substrate comprises an automotive component, a consumer product including a consumer electronic device, or other electronic device, such as a printed circuit board.

[0185] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.

Claims

1. 1. A low VOC composition for protecting a substrate from at least one undesirable contaminant, comprising: at least one film-forming component comprising a water-based carrier; At least one additive; Including, the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature ｇ a resin present in an amount sufficient to, and configured to, form a conformal film having the conformal film having a pencil hardness of less than 6B; Low VOC composition.

2. 10. The low VOC composition of claim 1, wherein the conformal film is deformable and electrically insulating when applied onto the substrate.

3. 10. The low-VOC composition of claim 1, wherein the at least one additive is present in the composition in an amount ranging from 0.001% to 40% by weight and comprises a filler, plasticizer, initiator, defoamer, surfactant, antioxidant, hydrophobizing agent, biocide, leveling agent, substrate wetting agent, crosslinker, dye, pigment, dispersant, passivator, adhesion promoter, coalescing agent or solvent, rheology modifier, UV absorber or stabilizer, or corrosion inhibitor.

4. The low-VOC composition of claim 3, the filler comprises functionalized fumed silica, non-functionalized fumed silica, precipitated silica, silica nanoparticles, alumina nanoparticles, zinc oxide nanoparticles, cellulose-based particles, or a combination thereof; the plasticizer comprises a polymeric plasticizer, a benzoate plasticizer, a phthalate plasticizer, a hydrogenated alicyclic hydrocarbon resin, trimellitate, a high molecular weight orthophthalate, a silicone oil, an octyl epoxy ester, or a hydrotreated light naphthenic petroleum distillate, or a combination thereof; the benzoate plasticizer comprises diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, or a combination thereof; and the polymeric plasticizer comprises poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, a bio-based alkyd, or a combination thereof; the initiator comprises a di- or polyfunctional alpha-hydroxyketone, an acylphosphine oxide, benzoyl formate, benzophenone, zinc oxide nanoparticles, a peroxide, an azo compound, or a combination thereof; the antifoaming agent comprises a silicone oil, a mineral oil, a vegetable oil, a polar oil, a molecular antifoaming agent, a hydrophobic nanoparticle, an emulsifier, a solvent, or a combination thereof; the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, or a combination thereof; the hydrophobizing agent comprises a paraffin wax emulsion, a modified paraffin wax, a paraffin / polyethylene wax emulsion, a silicone resin, or a combination thereof; the biocidal agent comprises an isothiazolinone, a formaldehyde-releasing biocide (FA-R), a carbamate-containing fungicide, or a combination thereof; the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, or a combination thereof; the leveling agent comprises a silicone, a liquid polyacrylate, an ionic surfactant, a non-ionic surfactant, a fluorosurfactant, or a combination thereof; the substrate wetting agent comprises a siloxane, a multifunctional surfactant, a polyglycol ether, a modified polyglycol ether, or a combination thereof; the dye comprises a stilbene compound, a distyrylbiphenyl derivative, a benzoxazole, or a combination thereof; the crosslinker comprises zinc ammonium carbonate solution, a carbodiimide crosslinker, a melamine crosslinker, an aziridine crosslinker, a mono- or poly-functional aliphatic glycerol polyglycidyl ether based crosslinker, a mono- or poly-functional aliphatic epoxy, an ethylene glycol diglycidyl ether, an oxazoline reactive polymer, a polyol, a polyisocyanate, a methylacrylamide, a dihydrazide crosslinker, an organofunctional silane, a metal complex, a UV-unstable functional monomer, or a combination thereof; the pigment comprises an organic pigment, an inorganic pigment, or a combination thereof; the dispersing agent comprises a fatty acid modified polyester, a sodium salt of an acrylic polymer, an ammonium salt of a hydrophobic copolymer, a modified polyacrylate, a zwitterionic surfactant, or a combination thereof; the adhesion promoter comprises a silane, an ethylene copolymer, a hydroxyl-functional copolymer, or a combination thereof; the coalescing agent comprises a glycol ether, an ester alcohol, or a combination thereof; The UV absorber or stabilizer comprises a hydroxy-phenyl-benzo-triazole, a hydroxy-phenyl-triazine, a hydroxy-benzophenone, a sterically hindered amine, or a combination thereof; the corrosion inhibitor comprises an organic acid amine complex, zinc phosphate, or a combination thereof; the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, or a combination thereof; The low VOC composition.

5. The low-VOC composition of claim 4, The phenolic antioxidant is selected from the group consisting of benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, octadecyl ester; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester; isomeric reactants of C7-9-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionates; selected from 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-; benzenepropanoic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-, 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl) ester; or reaction products with phenol, 4-methyl-, dicyclopentadiene and isobutylene, and combinations thereof; the amine antioxidant is selected from benzeneamine, N-phenyl-, reaction products with 2,4,4-trimethylpentene; 1-naphthalenamine, N-phenyl-ar-(1,1,3,3-tetramethylbutyl); 4,4'-dioctyldiphenylamine; other alkylated amines, and combinations thereof; the thioether antioxidant is selected from propanoic acid, 3-(dodecylthio)-, 1,1′-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or propanoic acid, 3,3′-thiobis-, 1,1′-ditridecyl ester, and combinations thereof; the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylidenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tetratridecylbis(phosphine); 12H-dibenzo[d,g][1,3,2]dioxaphosphocine, 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-; and combinations thereof; The passivating agent is dodecanedioic acid, 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 1,2,4-triazole, 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide; 1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-ar-methyl-; 1H-1,2,4-triazole-1-methanamine, N,N-bis(2-ethylhexyl)-; and combinations thereof, comprising a hydrazide or triazole selected from: 1,2,4-triazole, 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide; 1H-benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-ar-methyl-; 1H-1,2,4-triazole-1-methanamine, N,N-bis(2-ethylhexyl)-; and combinations thereof; the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, or combinations thereof; the adhesion promoter comprises a chlorinated polyolefin, a cyanoacrylate primer, a polyester alkyl ammonium salt, an amino-functional polyether, maleic anhydride, a carboxylated polypropylene, a glycidyl methacrylate functionalized polyolefin, trimethoxyvinylsilane, a silane, or a combination thereof; the substrate wetting or dispersing agent comprises an alkylammonium salt of a polycarboxylic acid, an alkylammonium salt of an acidic polymer, a salt of an unsaturated polyamine amide and an acidic polyester, a maleic anhydride functionalized ethylene butyl acrylate copolymer, another ionic or nonionic surfactant, or a combination thereof; and the tackifier comprises a hydrogenated hydrocarbon resin, an alicyclic hydrocarbon resin, or a combination thereof; The low VOC composition.

6. 10. The low-VOC composition of claim 1, wherein the conformal film has a thickness in the range of 25 nm to 500 μm.

7. said at least one film-forming component comprising a water-based carrier; 10. The low-VOC composition of claim 1, comprising an aqueous emulsion or dispersion comprising water in an amount ranging from 50 to 70% by weight and resin in an amount ranging from 30 to 50% by weight.

8. 10. The low-VOC composition of claim 1, wherein the water-based carrier does not contain any volatile organic solvents and is VOC-free.

9. 2. The low-VOC composition of claim 1, wherein the resin is selected from acrylic, styrene-acrylic, silicone, polyurethane, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

10. Higher T than the first resin ｇ 10. The low-VOC composition of claim 1, further comprising an additional resin having the formula:

11. 10. The low VOC composition of claim 1, wherein the at least one film-forming component comprises a blend of the resin and a self-crosslinking resin.

12. 4. The low-VOC composition of claim 3, comprising a plasticizer in an amount of up to 40% by weight.

13. 10. The low-VOC composition of claim 1 having a volatile organic content of 100 g / L or less.

14. 10. The low-VOC composition of claim 1 having no volatile organic content.

15. 10. The low-VOC composition of claim 1, wherein the at least one undesirable contaminant comprises one or more liquids, solids, gases, or combinations thereof, and includes water, sweat, or other moisture, dirt, dust, conductive metal particles, metal shavings, other conductive particulate matter and chemicals, or combinations thereof.

16. A method for making the low-VOC composition of any one of claims 1 to 15, comprising: providing a film-forming component comprising a water-based carrier; combining at least one additive with said film-forming ingredients including a water-based carrier; Including, the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature ｇ a resin present in an amount sufficient to, and configured to, form a conformal film having the conformal film having a pencil hardness of less than 6B; method.

17. 17. The method of claim 16, wherein the step of providing the film-forming component comprises at least one polymerization step comprising reacting at least one monomer, oligomer, or prepolymer to produce a film-forming polymer resin that can be dispersed or suspended in a water-based carrier with at least one additive to form the low-VOC composition.

18. 18. The method of claim 17, wherein the monomer, oligomer, or prepolymer comprises one or more functional groups capable of participating in a polymerization reaction.

19. 18. The method of claim 17, wherein the polymerization step proceeds by addition or polycondensation or a combination thereof.

20. 18. The method of claim 17, wherein the polymerizing step occurs after the at least one monomer, oligomer, or prepolymer is dispersed or suspended in the water-based carrier.

21. 18. The method of claim 17, wherein the polymerization step produces a reaction product which is then dispersed or suspended in the water-based carrier.

22. 20. The method of claim 17, wherein one or more of the following by-products are produced: water, ammonia, and compounds formed by the condensation reaction.

23. 1. A method of coating a substrate, comprising: Coating the substrate with a low VOC composition according to any one of claims 1 to 15, comprising at least one film-forming component with a water-based carrier and at least one additive. Including, the at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to a substrate at room temperature ｇ a resin present in an amount sufficient to, and configured to, form a conformal film having the conformal film having a pencil hardness of less than 6B; method.

24. 24. The method of claim 23, wherein the coating is applied using one or more methods selected from atomized or non-atomized spray coating, needle dispensing, dipping, jetting, blade coating, brushing, inkjet printing, crosslinking with UV light, crosslinking with heat, crosslinking using humidity, or a combination thereof.

25. 1. A coating configured to protect a substrate from undesired contaminants, comprising:

16. The low-VOC composition according to any one of claims 1 to 15, comprising at least one film-forming component and at least one additive. Including, The at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to the substrate at room temperature. ｇ a resin present in an amount sufficient to, and configured to, form a conformal film having the conformal film having a pencil hardness of less than 6B; coating.

26. 26. The coating of claim 25, wherein the at least one undesirable contaminant comprises one or more liquids, solids, gases, or combinations thereof, and is selected from water, sweat, or other moisture, dirt, dust, conductive metal particles, metal shavings, and other conductive particulate matter and chemicals, and combinations thereof.

27. 1. A substrate comprising a low-VOC coating, the low-VOC coating comprising:

16. The low-VOC composition according to any one of claims 1 to 15, comprising at least one film-forming component and at least one additive. Including, The at least one film-forming component has a glass transition temperature (T) of less than 25° C. when applied to the substrate at room temperature. ｇ a resin present in an amount sufficient to, and configured to, form a conformal film having the conformal film having a pencil hardness of less than 6B; substrate.