Conformal coating with low volatile organic compound content

Abstract

Disclosed is a coating composition comprising: at least one film-forming component comprising an aqueous-based carrier, a resin, and at least one additive wherein the coating composition does not comprise a highly volatile organic compound (VOC) content, and the resin is present in a sufficient amount and is configured to form a conformal film when applied to a substrate at room temperature. A conformal coating, a method of preparing the coating composition, a method of using the coating composition to protect a substrate, such as an electronic device including a printed circuit board assembly (PCBA), from undesired contaminants are also disclosed. Substrates coated with such conformal coatings are also disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to compositions with low or no volatile organic compounds (VOCs), conformal coatings that form deformable insulating films, which are designed to protect substrates such as electronic devices or printed circuit board assemblies (PCBAs). The present disclosure also relates to methods of preparing such compositions by applying the disclosed compositions to desired portions of substrates such as printed circuit boards of electronic devices, which protect substrates such as electronic devices or PCBAs from contaminants. The present disclosure also relates to substrates coated with conformal coatings using the compositions. Background Art

[0002] Electronic devices include conductive components that can be adversely affected when exposed 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, as such devices become more complex and feature more functions, they are used in more hazardous environments, such as humid environments, environments with corrosive gases, aerosolized or bulk liquids, or conductive particles that can degrade the functionality of the device.

[0003] When exposed to these environments, electronic devices can fail because the conductive medium may provide a path for unintended current flow between components under bias. Most of these failures manifest as corrosion of electronic components or failure of component performance. In addition to component failure, films formed by conformal coatings may also fail under these harsh conditions due to chemical degradation, which may ultimately lead to loss of electrical insulation or protective properties.

[0004] In addition to failures caused by environmental factors, designers of electronic devices and PCBAs are also constrained by creepage and clearance design requirements, which dictate the spacing between electronic components during PCBA design. Modern applications require higher power in the same device size or miniaturization of existing designs, so electrically insulating coatings can provide a dielectric barrier between electronic components, thereby reducing the required creepage and clearance distances.

[0005] As a result, durable electrically insulating coatings are becoming a more popular form of protection for such devices. The application of traditional coatings requires masking certain parts to ensure that the flow of current through connectors, test points or ground contacts is not inhibited. This process is expensive and time consuming, which has a detrimental effect on the overall electronic device manufacturing process.

[0006] Conventional conformal coatings are intended to improve their durability by increasing their mechanical strength. In addition, conventional conformal coatings rely on forming a highly cross-linked network that is not easily deformed. This results in a hard and rigid film that requires compromises during the electronic device manufacturing process (e.g., shielding certain components or selectively coating around certain components). In addition, some conformal coatings are formulated using coating compositions containing volatile organic solvents because these solvents have favorable properties as diluents and carriers. However, these volatile solvents are generally flammable and are harmful to the environment and the operators of the coating application equipment.

[0007] Therefore, conformal coatings that do not contain high volatile organic compound ("VOC") content are needed to protect electronic devices. These coatings need to comply with limits set by EU REACH and China's Blue Sky Initiative, as well as other regulatory agencies at the national and local levels. For example, in China, GB 30981-2020 sets the allowable VOC content standards for industrial protective coatings, with a limit of ≤650 grams per liter (g / L) for "electrical and electronic product coatings" of the solvent-based "varnish" type. In addition, the voluntary standard GB / T 38597-2020 recommends a lower limit of ≤480g / L for construction machinery. Other regions, including North America, Europe, and other parts of Asia, are expected to adopt similar or even stricter restrictions.

[0008] There is also a need for methods and uses of such low VOC coatings that allow protection of electronic devices from contaminants (e.g., solid particles, including dust, dirt, and metal shavings, as well as liquids, such as water and body fluids, including sweat). In addition, there is a need for conformal coatings made from such materials that can be applied without masking the component prior to coating so that it can cover the entire printed circuit board without inhibiting the function of the device.

[0009] The disclosed coating compositions and deformable low VOC conformal coatings made therefrom are directed to overcoming one or more of the problems set forth above and / or other problems of the prior art. Summary of the invention

[0010] In view of the foregoing, a low VOC composition for protecting a substrate from at least one undesirable contaminant is disclosed. In one embodiment, the disclosed composition comprises: at least one film-forming component comprising an aqueous carrier; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

[0011] Also disclosed is a method of preparing a low VOC composition for protecting a substrate from at least one undesirable contaminant. In one embodiment, the method includes providing a film-forming component comprising an aqueous carrier and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

[0012] Also disclosed is a method of coating an electronic device with a conformal coating, the conformal coating comprising a coating composition comprising a low VOC content or no VOC and comprising a glass transition temperature (T g ) a film former in a water-based carrier at a temperature below 25° C. In one embodiment, the method of applying such a conformal coating includes spraying, film coating, dipping, knife coating, needle dispensing, rolling, brushing, printing or spraying.

[0013] A low VOC coating configured to protect a substrate from unwanted contaminants is also disclosed. In one embodiment, the coating is formed on a substrate using a low VOC composition comprising: at least one film-forming component comprising a water-based carrier; and at least one additive. In one embodiment, the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

[0014] Also disclosed is an article or device, such as an electronic device, comprising a conformal coating as described herein, and a method of applying such a coating. In one embodiment, an electronic device comprising a deformable and electrically insulating conformal coating is described. The conformal coating is formulated using water as an evaporation carrier medium. In this embodiment, the film-forming element has a glass transition temperature (T g ), wherein the film former is deformable at room temperature and electrically insulating.

[0015] In one embodiment, a substrate comprising a coating prepared from the composition is disclosed. 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 comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film. DETAILED DESCRIPTION

[0016] As used herein, "conformal coating" refers to a film that follows the contours of a substrate (such as a printed circuit board or its components) to which it is applied in a continuous manner without interruptions or openings. The conformal coatings described herein protect substrates such as electronic circuits from the environment and liquids or particles, 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 a liquid material that is coated on a substrate, such as a printed circuit board or components thereof, during a coating application process.

[0018] As used herein, "aqueous" coating compositions refer to formulations consisting of aqueous resins or compounds, additives and fillers. Aqueous resins or compounds mean resins or compounds that use water and other organic solvents as evaporation carrier media. These resins or compounds are immiscible or insoluble in water and form emulsions or dispersions when mixed with water. Therefore, when used herein, "aqueous" describes a composition that uses water as the primary carrier medium.

[0019] As used herein, "coalescent" refers to an organic compound that aids in the coalescence of particles. In polymer emulsions or dispersions, the coalescence of particles when applied to a substrate is necessary for the formation of a continuous film. For example, in the case of a latex emulsion, a coalescent can help the latex particles coalesce into a continuous film. Non-limiting examples of such coalescents include benzoates, glycol ethers, and alcohol esters.

[0020] As used herein, "film former" refers to a material that is capable of forming a cohesive, continuous film when applied to a solid surface.

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

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

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

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

[0025] As used herein, "viscoelasticity" means a material that exhibits both viscous and elastic properties when undergoing deformation (i.e., the material both stores and dissipates energy during periodic / cyclic oscillatory shear deformation). This is typically reported with non-zero measurable values ​​of the storage modulus G' and the loss modulus G".

[0026] As used herein, "viscoplasticity" refers to the inelastic behavior of a material in which the material undergoes an irreversible 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. A viscoplastic material has a yield stress below which it will not flow, whereas a viscoelastic material will deform and flow under the application of any finite shear stress.

[0027] As used herein, "viscoelastic" refers to a large class of materials, such as the conformal coatings described in this patent, that exhibit elastic, viscous, and plastic response characteristics under varying 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 instead undergoes transient deformations in which some of the strain is elastically accumulated and some of the energy is dissipated through plastic (irreversible) deformation. When 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., it has measurable elastic modulus values ​​G' and loss modulus G") because some of the initial deformation is elastically stored and some of the external work applied to the material is viscous. When the applied load is removed, this viscoelastic response can be distinguished in a rheometer by partial (i.e., elastic) recoil or unloading, but due to the plastic nature of the material, some irreversible deformation is accumulated.

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

[0029] As used herein, the glass transition temperature, T g, is the temperature at which an amorphous polymer changes from a hard or glassy state to a soft or rubbery state (or vice versa). For waterborne resins, the specified T g is the T of the final film formed when water evaporates. g .

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

[0031] As used herein, "crosslinking" refers to linking two or more polymer chains by chemical or physical association. "Self-crosslinking resin" refers to a room temperature curing system supplied as a one-part system and does not require the addition of an external crosslinking agent before application. The crosslinking reaction can be triggered or initiated by different factors. Non-limiting examples of such factors include evaporation of water, changes in pH (such as a sharp drop in pH), exposure to UV radiation, and combinations thereof.

[0032] As used herein, "volatile organic compounds" or "VOCs" are those compounds that have poor water solubility and high vapor pressure. Governments, regulatory agencies, and non-governmental organizations around the world have developed more specific definitions for VOCs. For example, 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) defines VOCs as any carbon compound that participates in atmospheric photochemical reactions, excluding carbon monoxide, carbon dioxide, carbonic acid, metal carbides or carbonates, and ammonium carbonate. In China, VOCs are defined as organic chemicals with a vapor pressure of 0.01 kPa or more at room temperature (20°C), or organic chemicals that are sensitive to light reactions.

[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. The definition of VOC varies from country to country, and sometimes even in different regions of a country. As used herein, "low VOC" ranges from no VOC (i.e., 0 g / L) to a content of less than 300 g / L.

[0034] As used herein, "contaminants" refers to unwanted liquids, solids, gases, or combinations thereof. In one embodiment, contaminants may include corrosive gases that create a corrosive environment or solid particles 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.

[0035] As used herein, "REACH" (Registration, Evaluation, Authorisation and Restriction of Chemicals) is a European Union regulation implemented on June 1, 2007, which aims to improve the protection of human health and the environment from the risks that chemicals may pose. It also promotes alternative methods for the hazard assessment of substances in order to reduce the number of animal tests.

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

[0037] The present disclosure includes compositions for forming conformal coatings, wherein the conformal coating compositions have a low volatile organic compound (VOC) content or are VOC-free. The conformal coating compositions are aqueous. The low VOC composition comprises at least one film-forming component. The film-forming component comprises a water-based carrier, and the low VOC composition further comprises at least one additive. At least one film-forming component comprises a resin present in a sufficient 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.

[0038] The aqueous conformal coating composition comprises an aqueous resin, such as an acrylic resin, a styrene-acrylic resin, a silicone, a polyurethane, a styrene-butadiene, acrylonitrile-butadiene, and combinations thereof. In one embodiment, the aqueous resin is specifically selected such that the glass transition temperature (T g ) is below 25°C. This results in a soft film that forms at room temperature without the need for volatile organic solvents when the water evaporates. In one embodiment, the waterborne resin has a glass transition temperature (T) of -130°C to below 25°C. g In another embodiment, the glass transition temperature of the resin is from -60°C to less than 25°C.

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

[0040] In one embodiment, the aqueous emulsion or dispersion comprises the resin in an amount of 30% to 50% by weight of the total emulsion or dispersion system.

[0041] In one embodiment, the composition comprising the water-based carrier does not contain any volatile organic solvents 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.

[0042] In one embodiment, the conformal film is deformable and electrically insulating when applied to a substrate. When the coating composition is applied to an electronic device, the mechanical properties exhibited by the disclosed composition are designed so that applying the coating on the connector pins does not negatively affect the electrical contact resistance between the pins. This may include negligible changes in the insertion force required to mate the connector. In order to connect via the coating, the coating must be designed to have sufficient ductility in the normal, tensile and compressive directions and exhibit elastic-viscoplastic flow properties. The coating can be designed to exhibit a pencil hardness of less than 6B. The storage modulus and loss modulus of the coating in the shear, tensile or compressive directions may be less than 10 at 25°C when measured at a frequency between 1 and 100 radians per second (rad / s). 6 Pa. When subjected to a yield stress of less than 10 in shear, compression or tension at 1 to 100 rad / s at 25°C 4 When the stress reaches 1.0 Pa, the coating may yield.

[0043] This low T g (e.g., below 25°C) may have excessive tack, which can be addressed by g Resin with higher T g The additional resin blending can reduce the higher T g Resins can be used with low T g Resins with the same or different chemical properties. g Resin options include alkyd resins, vinyl acrylic resins, and vinyl acetate-ethylene copolymers. Alternatively, blending with self-crosslinking resins can also reduce the tack of the final coating. These modifications are carried out without losing the deformability of the coating composition. In some embodiments, the coating composition can be non-Newtonian and conformable before and when applied to the substrate.

[0044] The resins described herein include T g <0℃ polymer. For high T g Resins, non-limiting representative examples include alkyd resins, vinyl acrylic resins, and vinyl acetate-ethylene copolymers. High T g Coalescence of the resin can be improved by adding a coalescing solvent to the conformal coating composition in an amount of up to 300 g / L.

[0045] The aqueous resin described herein comprises a polymer emulsion or dispersion. Suitable polymers are thermoplastics having a molecular weight of 50,000 Daltons or more. The polymer is synthesized to have a T of 25°C or less. g .

[0046] A variety of polymer chemistries can be employed, including acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, alkyds, ethylene-acrylics, vinyl acetate-ethylene copolymers, and mixtures or copolymers thereof. In some embodiments, polymer emulsions and dispersions can be prepared by polymerization of monomers, oligomers, or combinations thereof. Non-limiting examples of monomers that can 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, propylene, butylene, isobutylene, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, hydroxypropyl acrylate, hydroxybutyl acrylate, styrene, α-methylstyrene, acrylonitrile, allyl methacrylate, acetoacetylethyl methacrylate (AAEM), diacetone acrylamide (DAAM), aminomethacrylate dimethyl, aminomethacrylate diethyl, silane-containing monomers, diol-containing monomers, diisocyanate monomers, and mixtures thereof.

[0047] In certain embodiments, polymer emulsions and dispersions can be prepared by a single-stage or multi-stage process. A multi-stage process can be used to produce polymers with different T g The polymer emulsions and dispersions prepared using a single-stage or multi-stage process can be prepared using a continuously varying addition of two or more monomers, or using a discrete sequential addition of two or more monomers or monomer mixtures.

[0048] In certain embodiments, a polymer may not exhibit a relative humidity corresponding to a single T when measured by differential scanning calorimetry. g A "gradient" polymer resin is an example of this phenomenon, where the composition changes during polymerization. For such polymer resins, the monomers are selected so that the deformability of the resin still meets the requirements outlined in the present invention.

[0049] In certain embodiments, crosslinkable groups and other additives may be added as part of the monomer mixture or may be added post-additive. Crosslinking may be performed by heating, UV exposure, water evaporation, rapid pH drop, or addition of a crosslinker prior to application in a two-part system.

[0050] During polymerization, a surfactant can be used. The surfactant can be selected from nonionic surfactants, anionic surfactants, cationic surfactants and combinations thereof. Non-limiting examples of surfactants that can be used herein can 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 copolymerized with monomers during polymerization.

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

[0052] In certain embodiments, the emulsion or dispersion can 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 can be used to produce an emulsion from a preformed polymer, a surfactant, a carrier fluid (such as water), and combinations thereof. In addition, additives or low T g Resins are added to an already formed emulsion to enhance its durability or deformability. In some embodiments, the emulsion or dispersion may be prepared by preparing a dispersion of a polymer synthesized by other methods including bulk and solution polymerization using water and a surfactant or other dispersant.

[0053] In one embodiment, the conformal coating composition can be prepared by low shear mixing of the resins in the desired ratio until a homogeneous mixture is obtained. Typical ratios for blending are low T g50 wt % to 100 wt % of the resin, which can be a chemical substance or a combination of chemical substances, including acrylic resins, styrene-acrylic resins, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene. The coating composition can be applied to the desired substrate and then dried at room temperature. Adding up to 50 g / L of alcohol (such as methanol or isopropanol) can also increase the drying speed. A drying oven or other methods of introducing air flow to reduce ambient humidity can be used to increase the drying speed. Although not necessary, the drying speed can be increased by heating in an oven. Additional protection for PCBA can be achieved by bottom filling components such as integrated circuits and ball grid arrays. The drying speed of the coating applied under the component can be accelerated by heating. For printed circuit boards with connector pins, these pins do not need to be shielded, and the coating can be applied directly thereon, thereby reducing production time and cost. Alternative compositions that can give the same results can also include low T introducing a crosslinking agent. g Resins. In one embodiment, if the pot life of the mixture is limited, these compositions can be applied as a two-part system. In one embodiment, crosslinking is performed by UV irradiation or heating.

[0054] In one embodiment, the coating composition can be prepared with one or more additives to further enhance the coating properties. Such additives include fillers, plasticizers, initiators, defoamers, surfactants, antioxidants, hydrophobic agents, biocides, leveling agents, substrate wetting agents, crosslinking agents, dyes, pigments, dispersants, passivators, tackifiers, coalescing agents or solvents, rheology modifiers, UV absorbers or stabilizers, and preservatives. 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.

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

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

[0057] In one embodiment, a plasticizer accounting for up to 40% of the total composition is added to further soften the film. In another embodiment, a plasticizer of up to 25% is added. The plasticizer can be selected from polymer plasticizers, benzoate plasticizers and phthalate plasticizers as additives for the disclosed coating composition. Examples of benzoate plasticizers can include diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate and combinations thereof. Examples of polymer plasticizers can include poly[oxy(methyl-1,2-ethanediyl)], α-(methylphenyl)-ω-hydroxy, bio-based alkyd resins and combinations thereof. In one embodiment, the plasticizer can include hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalates, silicone oils, octyl epoxy esters or hydrogenated light cycloalkyl petroleum distillates and combinations thereof.

[0058] In one embodiment, the additive may include an initiator. Examples of such initiators may include difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

[0059] In one embodiment, the additive may include a defoamer. Examples of such defoamers may include silicone oil, mineral oil, vegetable oil, polar oil, molecular defoamers, hydrophobic nanoparticles, emulsifiers, solvents, and combinations thereof.

[0060] In one embodiment, the additive may include a molecular defoamer such as a gemini surfactant, which has a dimer structure consisting of two hydrophobic chains and two hydrophilic heads connected by a spacer at or near the head group. In addition to the chemistries listed above, the waterborne epoxy system can be designed so that the film formed is deformable by reducing the degree of crosslinking in the system.

[0061] In one embodiment, the additive may include a hydrophobic agent including paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

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

[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.

[0064] In one embodiment, the additive may include a leveling agent including modified silicone, fluorosurfactant, and combinations thereof. In other embodiments, the leveling agent may include silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, and combinations thereof.

[0065] In one embodiment, the additive may include a substrate wetting agent including silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

[0066] In one embodiment, additive can include dye, and this dye includes distyrene compound, distyrene biphenyl derivative, benzoxazole and their combination.In one embodiment, additive can include crosslinking agent.Crosslinking agent can include zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or multifunctional aliphatic glycerol polyglycidyl ether crosslinking agent, monofunctional or multifunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyvalent alcohol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and their combination.

[0067] In one embodiment, additives may include pigments. Pigments may include organic or inorganic pigments and combinations thereof. In other embodiments, organic and inorganic pigments may include borophosphates, borosilicates, phosphates and phosphosilicates, color pigments and dyes comprising inorganic pigments, organic pigments and dispersions of pigments and dispersants, carbon black, special effect pigments, titanium dioxide and combinations thereof. In an alternative embodiment, pigments may be added to impart color or functionality including antiseptic properties.

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

[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.

[0070] In one embodiment, the additive may include a coalescing agent including glycol ethers, ester alcohols, and combinations thereof. In one embodiment, a high boiling coalescing solvent having a boiling point of 250° C. or higher may be used such that the solvent will evaporate slowly over time; for example, within a few minutes, within a few hours, or within a few days. In this case, the coalescing solvent acts as a temporary plasticizer, which can soften the film to make it deformable. Once the solvent is completely evaporated, the film will become hard. This is advantageous for applications that require deformability in the first few days after the coating process, but a harder film can provide more robust protection in the field.

[0071] In one embodiment, the additive may include a UV absorber or stabilizer including hydroxy-phenyl-benzo-triazoles, hydroxy-phenyl-triazines, hydroxy-benzophenones, sterically hindered amines, and combinations thereof.

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

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

[0074] In one embodiment, the antioxidant can be selected from phenolic antioxidants, including 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionic acid octadecyl ester; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionic acid 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester; isomers of the following substances in reaction quality: 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid C7- 9 alkyl esters; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylphenylpropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)ester; or the reaction product of 4-methylphenol with dicyclopentadiene and isobutylene; and combinations thereof. In one embodiment, the amine antioxidant can be selected from the reaction product of N-phenylaniline with 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof. In one embodiment, the thioether antioxidant may be selected from 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl]3-(dodecylthio)-propionic acid ester; or 1,1'-ditidecyl 3,3'-thiodipropionic acid ester; and combinations thereof. In one embodiment, the phosphite antioxidant may be selected from tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-triacontylbis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphine; and combinations thereof.

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

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

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

[0078] In one embodiment, the additive may include a substrate wetting agent or dispersant. Examples of such substrate wetting agents or dispersants 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 nonionic surfactants, and combinations thereof.

[0079] In one embodiment, the additive may include a tackifier including hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

[0080] In one embodiment, a method of preparing a low VOC composition for protecting a substrate from at least one undesirable contaminant may include providing a film-forming component and at least one additive. The film-forming component may include an aqueous carrier. At least one film-forming component may include a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

[0081] In one embodiment, providing a film-forming component for a method of preparing a low VOC composition may include at least one polymerization step. 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 along with at least one additive to form a low VOC composition. The monomer, oligomer, or prepolymer may contain one or more functional groups capable of participating in a polymerization reaction.

[0082] In one embodiment, the polymerizing step may be performed by addition or condensation polymerization or a combination thereof.

[0083] In one embodiment, the polymerization step may occur after at least one monomer, oligomer or prepolymer has been dispersed or suspended in the water-based carrier. The polymerization step may produce reaction products, which are then dispersed or suspended in the water-based carrier.

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

[0085] In one embodiment, at least one additive may be added to the polymerization reaction or post-added to the reaction product. The addition of monomers, oligomers or prepolymers may be performed in a single-stage or multi-stage process. For example, the addition of monomers, oligomers or prepolymers may be performed using a continuous variation of two or more monomers or a discrete sequential addition of two or more monomers or a monomer mixture.

[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 including a water-based carrier; and at least one additive. The at least one film-forming component may include a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

[0087] The coating can be applied to the substrate using a variety of techniques. Non-limiting examples of such techniques can include atomized or non-atomized spraying, needle dispensing, dipping, spraying, knife coating, brushing, inkjet printing, crosslinking by UV radiation, crosslinking by heating, crosslinking using humidity, or a combination thereof.

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

[0089] In one embodiment, once the coating composition is applied to the substrate and the carrying medium evaporates to leave the coating, an intermediate stage may exist. In some embodiments, the coating composition at the intermediate stage may have a residual amount of evaporated carrying medium. In some embodiments, the evaporated carrying medium may be water, a coalescing solvent, an alcohol, a pH neutralizer, or a combination thereof.

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

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

[0092] In one embodiment, the coating can be deposited on the substrate to obtain a film thickness of 25 nanometers (nm) to 500 micrometers (μm). When the coating composition is applied to the substrate to form a conformal coating, at least one component in the coating composition can be evaporated so that the coating can deform during evaporation and cannot deform after evaporation. In one embodiment, one of the components in the coating can be cross-linked so that the coating can deform during cross-linking and cannot deform after cross-linking.

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

[0094] The coating thickness can be measured by non-destructive optical techniques, such as ellipsometry, spectral 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 coatings and vacuum coatings, are typically much thicker than the disclosed coatings. For example, the thickness of conventional coatings is typically in the range of hundreds of microns, which may hinder the RF and Wi-Fi transmission of electronic devices and further act as thermal insulators. The thinner thickness range of the gel-state coating will not adversely affect the functionality of the electronic device, and its thermal impact on the device is negligible. A non-limiting example of a functional electronic device is a fully assembled printed circuit board. A fully assembled printed circuit board with a gel-state coating will exhibit normal RF performance, normal thermal properties, and other normal functions.

[0095] Measurement technology

[0096] After the coating has been applied to an electronic device, various properties can be measured in the following ways.

[0097] The hydrophobicity or hydrophilicity of a coating can be measured by observing the contact angle of a water drop on the coating surface. The oleophobicity or oleophilicity of a coating can be measured by observing the contact angle of a hexadecane drop on the coating surface.

[0098] The electrical insulation of the coating can also be determined by measuring the dielectric withstand voltage of the coated circuit board. A continuously increasing voltage can be applied to the coated circuit board and the voltage when the current arcs through the air can be determined. This voltage is a measure of the effectiveness of the coating.

[0099] The electrical insulation of the coating may also be determined by measuring the material electrical properties of the coating, such as the loss tangent or dielectric constant, using a network analyzer.

[0100] The non-Newtonian, viscoelastic, viscoplastic, and elasto-viscoplastic properties of a coating can be measured by observing various properties. A rheometer can be used to measure the response of a coating to an applied stress or strain to study the deformation of the coating. 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 extent of deformation can also be measured by quantifying hardness, modulus, adhesion, failure strain, creep, and ductility in tension, compression, and shear directions.

[0101]

[00136] Features and advantages of the compositions, coatings, and methods disclosed herein are illustrated by the following examples, which should not be construed as limiting the scope of the disclosure in any way.

[0102] Example

[0103] The conformal coating compositions are prepared by low shear mixing of resins in the desired proportions until a homogeneous mixture is obtained. Unless otherwise stated, the coating compositions are applied to the desired substrate by spraying or knife coating and then dried under ambient conditions. The invention is illustrated by the following examples.

[0104] Working Example 1

[0105] In this embodiment, 10 g of acrylic emulsion (T g : -42 ° C, 50% solids, pH: 7.7 to 8.2) was charged into a beaker. Under low shear mixing, 0.005 g of viscosity enhancer and 0.005 g of UV dye were added. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH between 7.7 and 8.2.

[0106] Working Example 2

[0107] In this embodiment, 10 g of acrylic emulsion (T g : -42 ° C, 50 wt% solids, pH: 7.7 to 8.2) was charged into a beaker. Under low shear mixing, 0.035 g of bactericide and 0.25 g of fungicide and 0.005 g of UV dye were added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.7 and 8.2.

[0108] Working Example 3

[0109] In this example, 8 g of acrylic emulsion (T g : -42°C, 50% solids, pH: 7.7 to 8.2) and 2 g of self-crosslinking styrene acrylic emulsion (T g : 23 ° C, 43 wt% solids, pH: 7.7 to 8.2) was charged into a beaker. Under low shear mixing, 0.005 g of UV dye was added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.7 and 8.2.

[0110] Working Example 4

[0111] In this example, 9 g of a self-crosslinking styrene-acrylic emulsion (minimum film forming temperature: 8 to 12° C., 48% solids, pH: 8.5 to 9.0) was charged into a beaker. Under low shear mixing, 2 g of deionized water, 0.05 g of a substrate wetting agent, 0.005 g of a UV dye, 0.04 g of a bactericide, 0.1 g of a fungicide, 0.1 g of a surfactant, and 1 g of a plasticizer were added. The pH was monitored throughout the mixing process, and a neutralizer was added to maintain the pH between 8.5 and 9.0.

[0112] Working Example 5

[0113] In this example, 9 g of a self-crosslinking styrene-acrylic emulsion (minimum film forming temperature: 8 to 12° C., 48 wt.% solids, pH: 8.5 to 9.0) was charged into 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 a neutralizer was added to maintain the pH between 8.5 and 9.0.

[0114] Working Example 6

[0115] In this example, 9 g of acrylic emulsion (T g :7°C, 57 wt% solids, pH: 7.5 to 9.5) was charged into 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 a neutralizer was added to maintain the pH between 7.5 and 9.5.

[0116] Working Example 7

[0117] In this example, 8.5 g of acrylic emulsion (T g:7°C, 57 wt% solids, pH: 7.5 to 9.5) was charged into a beaker. Under low shear mixing, 2.25 g of deionized water, 0.05 g of substrate wetting agent, 0.005 g of UV dye, 0.04 g of bactericide, 0.1 g of fungicide and 1.5 g of plasticizer were added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.5 and 9.5.

[0118] Working Example 8

[0119] In this example, 9.5 g of acrylic emulsion (T g : -42 ° C, 50 wt% solids, pH: 7.7 to 8.2) was charged into a beaker. Under low shear mixing, 0.5 g of hydrophobic fumed silica dispersion (pre-dispersed in water at 20 wt% solids) and 0.005 g of UV dye were added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.7 and 8.2.

[0120] Working Example 9

[0121] In this example, 8.5 g of acrylic emulsion (T g :7°C, 57 wt% solids, pH: 7.5 to 9.5) was charged into a beaker. Under low shear mixing, 2.25 g of deionized water, 0.05 g of substrate wetting agent, 0.005 g of UV dye, 0.015 g of leveling agent and 1.5 g of plasticizer were added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.5 and 9.5.

[0122] Working Example 10

[0123] In this example, 8.5 g of acrylic emulsion (T g :7°C, 57 wt% solids, pH: 7.5 to 9.5) was charged into a beaker. Under low shear mixing, 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 were added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.5 and 9.5.

[0124] Working Example 11

[0125] In this example, 9 g of acrylic emulsion (T g : -42°C, 50 wt% solids, pH: 7.7 to 8.2) and 1 g of silicone emulsion (T g: -41 ° C, 45 wt% solids, pH: 11) was charged into a beaker. Under low shear mixing, 0.005 g of UV dye was added. The pH was monitored throughout the mixing process and neutralizer was added to maintain the pH between 7.7 and 8.2.

[0126] Working Example 12

[0127] In this example, 9.6 g of acrylic emulsion (T g : -42 ° C, 50 wt% solids, pH: 7.7 to 8.2) and 0.4g paraffin wax emulsion (50 wt% solids) were charged into a beaker. Under low shear mixing, 0.005g UV dye was added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.7 and 8.2.

[0128] Working Example 13

[0129] In this embodiment, 10 g of acrylic emulsion (T g : -42 ° C, 50 wt% solids, pH: 7.7 to 8.2) and 0.1g of crosslinker (pre-dissolved in solution at 15 wt% solids) were charged into a beaker. Under low shear mixing, 0.005g of UV dye was added. The pH was monitored throughout the mixing process and a neutralizer was added to maintain the pH between 7.7 and 8.2.

[0130] Industrial Applicability

[0131] The present disclosure describes conformal coatings formulated as low VOC or VOC-free waterborne coatings designed to protect substrates, such as electronic devices or printed circuit board assemblies (PCBAs), from unwanted contaminants. In particular, the present disclosure is useful for manufacturers seeking moisture protection and having stringent VOC requirements, or those who wish to reduce smoke extraction and flammable storage requirements will benefit from the present invention. This includes general moisture protection of electrical insulation and non-electrical equipment / components for printed circuit board manufacturers where exposure to water may result in water-induced damage, such as corrosion, discoloration, or blemishes. In addition to performance benefits, low VOC or VOC-free coatings can reduce overall manufacturing costs and reduce the environmental impact of using conformal coatings.

[0132] Thus, in one embodiment, the invention is useful for protecting circuit boards from exposure to water or other harmful environmental elements while allowing modifications to the PCBA after assembly during the manufacturing process or product maintenance. These modifications may include rework of functional board connections or failed board components through the disclosed conformal coating. The disclosed conformal coating also facilitates accommodating thermal expansion or contraction of the PCBA without creating additional mechanical stress.

[0133] In another embodiment, the surface may include a metal and the undesirable environment is corrosive and aqueous, such as condensed water, tap water, sweat, sebum, salt water, carbonated beverages, coffee, liquid coolants, or antifreeze. In one embodiment, the surface includes a metal that exhibits galvanic corrosion, and the undesirable environment causes galvanic corrosion. More generally, the surface may include any metal that may undergo oxidation or other adverse chemical reactions due to a corrosive environment.

[0134] Once the water evaporates upon coating to form a continuous film, the conformal coating may exhibit viscoelastic, viscoplastic, or elasto-viscoplastic properties.

[0135] Conformal coatings may also have a thickness of 25 nm to 500 μm when applied on various surfaces.

[0136] Conformal coatings can conform to features with length scales less than 25nm and provide protection from corrosive environments.

[0137] In one embodiment, the compositions exhibit electrical insulating properties such that when the compositions are placed between two metal contacts, they prevent current leakage or arcing between the metal contacts. The electrical insulating properties may also prevent current from flowing from active electronic devices on a printed circuit board to a conductive medium or the environment, or prevent electrostatic discharge from charge carriers to active electronic devices on a printed circuit board. In one embodiment, the coating composition may be applied to automotive parts to form a conformal coating to protect from unwanted contaminants.

[0138] Described herein is a low VOC composition for protecting a substrate from at least one undesirable contaminant, the composition comprising: at least one film-forming component comprising an aqueous carrier; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T ) when applied to a substrate at room temperature. g ) below 25°C conformal film.

[0139] In one embodiment, in the low VOC compositions described herein, the conformal film is deformable and electrically insulating when applied to a substrate.

[0140] In one embodiment, in the low VOC composition described herein, at least one additive includes a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

[0141] In one embodiment, in the low VOC compositions described herein, at least one additive is present in the composition in an amount of 0.001 wt % to 40 wt %.

[0142] In one embodiment, the filler includes functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

[0143] In one embodiment, the plasticizers include polymeric plasticizers, benzoate plasticizers, and phthalate plasticizers.

[0144] In one embodiment, the benzoate plasticizers include diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

[0145] In one embodiment, the polymeric plasticizer includes poly[oxy(methyl-1,2-ethanediyl)], α-(methylphenyl)-ω-hydroxy, bio-based alkyd resins, and combinations thereof.

[0146] In one embodiment, the plasticizer includes hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalic acid esters, silicone oils, octyl epoxy esters, or hydrogenated light naphthenic petroleum distillates, and combinations thereof.

[0147] In one embodiment, the initiator includes difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

[0148] In one embodiment, the defoaming agent includes silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent and combinations thereof.

[0149] In one embodiment, the surfactant includes nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, and combinations thereof.

[0150] In one embodiment, the hydrophobic agent includes paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

[0151] In one embodiment, the biocide includes isothiazolinones, formaldehyde-releasing biocides (FA-R), carbamate-containing fungicides, and combinations thereof.

[0152] In one embodiment, the rheology modifier includes hydrophobically modified ethoxylated urethane (HEUR) type thickeners, alkali swellable emulsions, acrylic copolymers, and combinations thereof.

[0153] In one embodiment, the leveling agent includes silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant and combinations thereof.

[0154] In one embodiment, the substrate wetting agent includes silicones, multifunctional surfactants, polyethylene glycol ethers, modified polyethylene glycol ethers, and combinations thereof.

[0155] In one embodiment, the dye includes stilbene compounds, distyrylbiphenyl derivatives, benzoxazoles, and combinations thereof.

[0156] In one embodiment, the crosslinking agent includes zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether-based crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and their combination.

[0157] In one embodiment, pigments include borophosphates, borosilicates, phosphates and phosphosilicates, color pigments and dyes including inorganic pigments, organic pigments and dispersions of pigments and dispersants, synergists, carbon black, special effect pigments, titanium dioxide, and combinations thereof.

[0158] In one embodiment, the dispersant includes fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

[0159] In one embodiment, the adhesion promoter includes silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

[0160] In one embodiment, the coalescing agent includes glycol ethers, ester alcohols, and combinations thereof.

[0161] In one embodiment, the UV absorber or stabilizer includes hydroxy-phenyl-benzo-triazoles, hydroxy-phenyl-triazines, hydroxy-benzophenones, sterically hindered amines, and combinations thereof.

[0162] In one embodiment, the preservatives include organic acid amine complexes, zinc phosphate, and combinations thereof.

[0163] In one embodiment, the antioxidant includes phenolic antioxidants, amine antioxidants, thioether antioxidants, phosphite antioxidants, lactones, and combinations thereof.

[0164] In one embodiment, the phenolic antioxidant is selected from octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction quality: C7-9 alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate; 1,3,5-tris{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoate; or the reaction product of 4-methylphenol with dicyclopentadiene and isobutylene; and combinations thereof.

[0165] In one embodiment, the amine antioxidant is selected from the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

[0166] In one embodiment, the thioether antioxidant is selected from 1,1′-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl]3-(dodecylthio)-propionic acid ester; or 1,1′-ditidecyl 3,3′-thiodipropionic acid ester; and combinations thereof.

[0167] In one embodiment, the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tricarboxylic bis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphine; and combinations thereof.

[0168] In one embodiment, the passivating agent comprises a hydrazide or a triazole selected from dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

[0169] 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.

[0170] In one embodiment, the adhesion promoter includes chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes, and combinations thereof.

[0171] In one embodiment, substrate wetting or dispersing agents include alkylammonium salts of polycarboxylic acids, alkylammonium salts of acidic polymers, salts of unsaturated polyamine amides and acidic polyesters, maleic anhydride functionalized ethylene butyl acrylate copolymers, other ionic or nonionic surfactants, and combinations thereof.

[0172] In one embodiment, the tackifier includes hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

[0173] In one embodiment, the conformal film has a thickness of 25 nm to 500 μm,

[0174] In one embodiment, the at least one film-forming component comprising a water-based carrier comprises an aqueous emulsion or dispersion.

[0175] In one embodiment, the aqueous emulsion or dispersion comprises water in an amount of 50% to 70% by weight.

[0176] In one embodiment, the aqueous emulsion or dispersion comprises the resin in an amount of 30% to 50% by weight.

[0177] In one embodiment, the water-based carrier does not contain any volatile organic solvents and is VOC-free.

[0178] In one embodiment, the resin is selected from the group consisting of acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

[0179] In one embodiment, the composition further comprises a resin having a higher T than the first resin. g of additional resin.

[0180] In one embodiment, the additional resin has the same or different chemistry as the first resin.

[0181] In one embodiment, the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

[0182] In one embodiment, at least one film-forming component comprises a blend of a resin and a self-crosslinking resin.

[0183] In one embodiment, the composition comprises a plasticizer in an amount of up to 40% by weight.

[0184] In one embodiment, the composition has a volatile organic content of 100 g / L or less.

[0185] In one embodiment, the composition is free of volatile organics.

[0186] In one embodiment, the at least one undesirable contaminant includes one or more of liquids, particulates, corrosive environments, and combinations thereof.

[0187] 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.

[0188] Also described herein is a method of preparing a low VOC composition described herein and generally described above for protecting a substrate from at least one undesirable contaminant, the method comprising: providing a film-forming component comprising an aqueous carrier; and combining at least one additive with the film-forming component comprising the aqueous carrier, wherein at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T ) of 0.040 when applied to a substrate at room temperature. g ) below 25°C conformal film.

[0189] In one embodiment, 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 an aqueous carrier along with at least one additive to form a low VOC composition.

[0190] In one embodiment, the monomer, oligomer or prepolymer comprises one or more functional groups capable of participating in a polymerization reaction.

[0191] In one embodiment, the polymerizing step is performed by addition or condensation polymerization, or a combination thereof.

[0192] In one embodiment, the polymerization step occurs after at least one monomer, oligomer or prepolymer has been dispersed or suspended in the water-based carrier.

[0193] In one embodiment, the polymerization step produces reaction products which are then dispersed or suspended in an aqueous carrier.

[0194] In one embodiment, the method produces one or more of the following by-products: water, ammonia, and compounds produced by the condensation reaction.

[0195] Also described herein is a method of coating a substrate with a film comprising the low VOC composition described herein and generally described above, the method comprising: coating a substrate with a low VOC conformal coating composition comprising: at least one film-forming component comprising an aqueous carrier; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T ) when applied to a substrate at room temperature. g ) below 25°C conformal film.

[0196] In one embodiment, the coating application is performed using one or more methods selected from the group consisting of atomized or non-atomized spraying, needle dispensing, dipping, spraying, knife coating, brushing, inkjet printing, crosslinking by UV radiation, crosslinking by heating, crosslinking using humidity, or combinations thereof.

[0197] In one embodiment, the coating is deformable and electrically insulating when applied to the substrate.

[0198] Also disclosed is a coating configured to protect a substrate from unwanted 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 comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T ) when applied to a substrate at room temperature. g ) below 25°C conformal film.

[0199] Also disclosed is a substrate comprising a coating, wherein the coating comprises 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 comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T ) when applied to a substrate at room temperature.g ) below 25°C conformal film.

[0200] 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.

[0201] 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 exemplary only, with the true scope of the invention being indicated by the following claims.

Claims

1. A low VOC composition for protecting a substrate from at least one undesirable contaminant, the composition comprising: at least one film-forming component comprising an aqueous carrier; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

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

3. The low VOC composition of claim 1, wherein the at least one additive comprises a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

4. The low VOC composition of claim 1, wherein the at least one additive is present in the composition in an amount of 0.001 wt% to 40 wt%.

5. The low VOC composition of claim 3, wherein the filler comprises functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

6. The low VOC composition of claim 3, wherein the plasticizer comprises a polymer plasticizer, a benzoate plasticizer, and a phthalate plasticizer.

7. The low VOC composition of claim 6, wherein the benzoate plasticizer comprises diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

8. The low VOC composition of claim 6, wherein the polymeric plasticizer comprises poly[oxy(methyl-1,2-ethanediyl)], α-(methylphenyl)-ω-hydroxy, bio-based alkyd resins, and combinations thereof.

9. The low VOC composition of claim 3, wherein the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalic acid esters, silicone oils, octyl epoxy esters, or hydrogenated light naphthenic petroleum distillates, and combinations thereof.

10. The low VOC composition of claim 3, wherein the initiator comprises difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

11. The low VOC composition of claim 3, wherein the defoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent, and combinations thereof.

12. The low VOC composition of claim 3, wherein the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, and combinations thereof.

13. The low VOC composition of claim 3, wherein the hydrophobic agent comprises paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

14. The low VOC composition of claim 3, wherein the biocide comprises isothiazolinone, formaldehyde-releasing biocide (FA-R), carbamate-containing fungicide, and combinations thereof.

15. The low VOC composition of claim 3, wherein the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

16. The low VOC composition of claim 3, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

17. The low VOC composition of claim 3, wherein the substrate wetting agent comprises silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

18. The low VOC composition of claim 3, wherein the dye comprises a distyryl compound, a distyryl biphenyl derivative, a benzoxazole, and combinations thereof.

19. The low VOC composition of claim 3, wherein the crosslinking agent comprises zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether-based crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and combinations thereof.

20. The low VOC composition of claim 3, wherein the pigment comprises an organic pigment, an inorganic pigment, and combinations thereof.

21. The low VOC composition of claim 3, wherein the dispersant comprises fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

22. The low VOC composition of claim 3, wherein the adhesion promoter comprises silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

23. The low VOC composition of claim 3, wherein the coalescing agent comprises glycol ethers, ester alcohols, and combinations thereof.

24. The low VOC composition of claim 3, wherein the UV absorber or stabilizer comprises hydroxy-phenyl-benzo-triazole, hydroxy-phenyl-triazine, hydroxy-benzophenone, sterically hindered amine, and combinations thereof.

25. The low VOC composition of claim 3, wherein the preservative comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

26. The low VOC composition of claim 3, wherein the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, and combinations thereof.

27. The low VOC composition of claim 26, wherein the phenolic antioxidant is selected from octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction mass: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate; Acid C7-9 alkyl ester; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl) ester; or the reaction product of 4-methylphenol with dicyclopentadiene and isobutylene, and combinations thereof.

28. The low VOC composition of claim 26, wherein the amine antioxidant is selected from the group consisting of the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

29. The low VOC composition of claim 26, wherein the thioether antioxidant is selected from 3-(dodecylthio)-propionic acid 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or 3,3'-thiodipropionic acid 1,1'-ditidecyl ester; and combinations thereof.

30. The low VOC composition of claim 26, wherein the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-triacontylbis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphite; and combinations thereof.

31. The low VOC composition of claim 3, wherein the passivator comprises a hydrazide or a triazole selected from dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

32. The low VOC composition of claim 3, wherein the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

33. The low VOC composition of claim 3, wherein the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes, and combinations thereof.

34. The low VOC composition of claim 3, wherein the substrate wetting or dispersing agent comprises 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 nonionic surfactants, and combinations thereof.

35. The low VOC composition of claim 3, wherein the tackifier comprises hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

36. The low VOC composition of claim 1, wherein the conformal film has a thickness of 25 nm to 500 μm.

37. The low VOC composition of claim 1, wherein the at least one film-forming component comprising a water-based carrier comprises an aqueous emulsion or dispersion.

38. The low VOC composition of claim 37, wherein the aqueous emulsion or the aqueous dispersion comprises water in an amount of 50% to 70% by weight.

39. The low VOC composition of claim 37, wherein the aqueous emulsion or the aqueous dispersion comprises the resin in an amount of 30 to 50 weight percent.

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

41. The low VOC composition of claim 1, wherein the resin is selected from the group consisting of acrylic resins, styrene-acrylic resins, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

42. The low VOC composition of claim 1, further comprising a resin having a higher T than the first resin. g of additional resin.

43. The low VOC composition of claim 42, wherein the additional resin has the same or different chemical nature as the first resin.

44. The low VOC composition of claim 42, wherein the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

45. 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.

46. ​​The low VOC composition of claim 3, wherein the composition comprises a plasticizer in an amount of up to 40 weight percent.

47. The low VOC composition of claim 1, wherein the composition has a volatile organic content of 100 g / L or less.

48. The low VOC composition of claim 1, wherein the composition is free of volatile organics.

49. The low VOC composition of claim 1, wherein the at least one undesirable contaminant comprises one or more liquids, solids, gases, and combinations thereof.

50. The low VOC composition of claim 1, wherein the at least one undesirable contaminant comprises water, sweat or other moisture, dirt, dust, conductive metal particles, metal shavings and other conductive particulate matter and chemicals, and combinations thereof.

51. A method of preparing a low VOC composition for protecting a substrate from at least one undesirable contaminant, the method comprising: 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 comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

52. The method of claim 51 , wherein providing the film-forming components comprises at least one polymerization step comprising reacting at least one monomer, oligomer or prepolymer to produce a film-forming polymer resin capable of being dispersed or suspended in an aqueous carrier along with at least one additive to form the low VOC composition.

53. The method of claim 52, wherein the monomer, oligomer or prepolymer comprises one or more functional groups capable of participating in a polymerization reaction.

54. The method of claim 52, wherein the polymerizing step is performed by addition or condensation polymerization or a combination thereof.

55. The method of claim 52, wherein the polymerizing step occurs after the at least one monomer, oligomer or prepolymer has been dispersed or suspended in the water-based carrier.

56. The method of claim 52, wherein the polymerizing step produces a reaction product that is then dispersed or suspended in the water-based carrier.

57. The method of claim 52, wherein the method produces one or more of the following byproducts: water, ammonia, and compounds produced by condensation reactions.

58. The method of claim 51, wherein the at least one additive comprises a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

59. The method of claim 58, wherein the filler comprises functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, cellulose-based particles, and combinations thereof.

60. The method of claim 58, wherein the plasticizer comprises a polymeric plasticizer, a benzoate plasticizer, and a phthalate plasticizer.

61. The method of claim 60, wherein the benzoate plasticizer is selected from the group consisting of diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

62. The method of claim 60, wherein the polymeric plasticizer is selected from the group consisting of poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, or bio-based alkyd emulsions, and combinations thereof.

63. The method of claim 58, wherein the initiator comprises difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

64. The method of claim 58, wherein the defoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent, and combinations thereof.

65. The method of claim 58, wherein the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, and combinations thereof.

66. The method of claim 58, wherein the hydrophobic agent comprises paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

67. The method of claim 58, wherein the biocide comprises isothiazolinone, formaldehyde-releasing biocide (FA-R), carbamate-containing fungicide, and combinations thereof.

68. The method of claim 58, wherein the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

69. The method of claim 58, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

70. The method of claim 58, wherein the substrate wetting agent comprises silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

71. The method of claim 58, wherein the dye comprises a distyryl compound, a distyryl biphenyl derivative, a benzoxazole, and combinations thereof.

72. The method of claim 58, wherein the crosslinking agent comprises zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether-based crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and combinations thereof.

73. The method of claim 58, wherein the pigment comprises an organic pigment, an inorganic pigment, and combinations thereof.

74. The method of claim 58, wherein the dispersant comprises fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

75. The method of claim 58, wherein the adhesion promoter comprises silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

76. The method of claim 58, wherein the coalescing agent comprises glycol ethers, ester alcohols, and combinations thereof.

77. The method of claim 58, wherein the UV absorber or stabilizer comprises hydroxy-phenyl-benzo-triazole, hydroxy-phenyl-triazine, hydroxy-benzophenone, sterically hindered amines, and combinations thereof.

78. The method of claim 58, wherein the preservative comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

79. The method of claim 58, wherein the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, and combinations thereof.

80. The method of claim 79, wherein the phenolic antioxidant is selected from octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction mass: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid C7 -9 alkyl ester; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl bis(2,2-dimethyl-2,1-ethanediyl) ester; or the reaction product of 4-methylphenol with dicyclopentadiene and isobutylene; and combinations thereof.

81. The method of claim 79, wherein the amine antioxidant is selected from the group consisting of the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

82. The method of claim 79, wherein the thioether antioxidant is selected from 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl]3-(dodecylthio)-propionate; or 1,1'-ditidecyl 3,3'-thiodipropionate; and combinations thereof.

83. The method of claim 79, wherein the phosphite antioxidant is selected from the group consisting of tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tricarboxylic bis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphine; and combinations thereof.

84. The method of claim 58, wherein the passivating agent comprises a hydrazide or a triazole selected from the group consisting of dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

85. The method of claim 58, wherein the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

86. The method of claim 58, wherein the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes, and combinations thereof.

87. The method of claim 58, wherein the substrate wetting or dispersing agent comprises 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 nonionic surfactants, and combinations thereof.

88. The method of claim 58, wherein the tackifier comprises hydrogenated hydrocarbon resins, alicyclic hydrocarbon resins, and combinations thereof.

89. The method of claim 58, wherein the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitates, high molecular weight phthalates, silicone oils, octyl epoxy esters, or hydrogenated light naphthenic petroleum distillates, and combinations thereof.

90. The method of claim 58, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

91. The method of claim 51, wherein the at least one additive is added to the polymerization reaction or post-added to the reaction product.

92. The method of claim 52, wherein the addition of the monomer, oligomer or prepolymer is performed in a single stage or a multi-stage process.

93. The method of claim 52, wherein the addition of the monomers, oligomers or prepolymers is performed using a continuously varying addition of two or more monomers, or using a discrete sequential addition of two or more monomers or monomer mixtures.

94. The method of claim 51, wherein the conformal film has a thickness of 25 nm to 500 μm, 95. The method of claim 51, wherein the at least one film-forming component comprising a water-based carrier comprises an aqueous emulsion or dispersion.

96. The method of claim 95, wherein the aqueous emulsion or the aqueous dispersion comprises water in an amount of 50% to 70% by weight.

97. The method of claim 95, wherein the aqueous emulsion or the aqueous dispersion comprises the resin in an amount of 30% to 50% by weight.

98. The method of claim 51, wherein the water-based carrier does not contain any volatile organic solvents and is VOC-free.

99. The method of claim 51, wherein the resin is selected from the group consisting of acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

100. The method of claim 51, further comprising having a higher T than the first resin. g of additional resin.

101. The method of claim 100, wherein the additional resin has the same or different chemical nature as the first resin.

102. The method of claim 101, wherein the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

103. The method of claim 51, wherein the at least one film-forming component comprises a blend of the resin and a self-crosslinking resin.

104. The method of claim 51 wherein the low VOC composition comprises a plasticizer in an amount of up to 40 weight percent.

105. The method of claim 51, wherein the low VOC composition has a volatile organic content of 100 g / L or less.

106. The method of claim 51, wherein the low VOC composition contains no volatile organic compounds.

107. The method of claim 51, wherein the at least one undesirable contaminant comprises one or more of liquids, solids, gases, and combinations thereof.

108. The method of claim 51, wherein the at least one undesirable contaminant comprises water, sweat or other moisture, dirt, dust, conductive metal particles, metal shavings and other conductive particulate matter and chemicals, and combinations thereof.

109. A method of coating a substrate, the method comprising: coating the substrate with a low VOC composition as a coating, the 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 comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

110. The method of claim 109, wherein the coating application is performed using one or more methods selected from the group consisting of atomized or non-atomized spraying, needle dispensing, dipping, spraying, knife coating, brushing, inkjet printing, crosslinking by UV radiation, crosslinking by heating, crosslinking using humidity, or a combination thereof.

111. The method of claim 109, wherein the coating is deformable and electrically insulating when applied to a substrate.

112. The method of claim 109, wherein the at least one additive comprises a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

113. The method of claim 112, wherein the filler comprises functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

114. The method of claim 112, wherein the plasticizer comprises a polymer plasticizer, a benzoate plasticizer, and a phthalate plasticizer.

115. The method of claim 114, wherein the benzoate plasticizer comprises diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

116. The method of claim 114, wherein the polymeric plasticizer comprises poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, bio-based alkyd resins, and combinations thereof.

117. The method of claim 112, wherein the initiator comprises a difunctional or multifunctional α-hydroxy ketone, an acylphosphine oxide, a benzoylformate, a benzophenone, zinc oxide nanoparticles, a peroxide, an azo compound, and combinations thereof.

118. The method of claim 112, wherein the defoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent, and combinations thereof.

119. The method of claim 112, wherein the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, and combinations thereof.

120. The method of claim 112, wherein the hydrophobic agent comprises paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

121. The method of claim 112, wherein the biocide comprises isothiazolinone, formaldehyde-releasing biocide (FA-R), carbamate-containing fungicide, and combinations thereof.

122. The method of claim 112, wherein the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

123. The method of claim 112, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

124. The method of claim 112, wherein the substrate wetting agent comprises silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

125. The method of claim 112, wherein the dye comprises a distyryl compound, a distyryl biphenyl derivative, a benzoxazole, and combinations thereof.

126. The method of claim 112, wherein the crosslinking agent comprises zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether-based crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and combinations thereof.

127. The method of claim 112, wherein the pigment comprises an organic pigment, an inorganic pigment, and combinations thereof.

128. The method of claim 112, wherein the dispersant comprises fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

129. The method of claim 112, wherein the adhesion promoter comprises silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

130. The method of claim 112, wherein the coalescing agent comprises glycol ethers, ester alcohols, and combinations thereof.

131. The method of claim 112, wherein the UV absorber or stabilizer comprises hydroxy-phenyl-benzo-triazole, hydroxy-phenyl-triazine, hydroxy-benzophenone, sterically hindered amines, and combinations thereof.

132. The method of claim 112, wherein the preservative comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

133. The method of claim 112, wherein the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, and combinations thereof.

134. The method of claim 133, wherein the phenolic antioxidant is selected from octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction mass: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate C 7-9 alkyl ester; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl bis(2,2-dimethyl-2,1-ethanediyl) ester; or the reaction product of 4-methylphenol with dicyclopentadiene and isobutylene; and combinations thereof.

135. The method of claim 133, wherein the amine antioxidant is selected from the group consisting of the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

136. The method of claim 133, wherein the thioether antioxidant is selected from 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl]3-(dodecylthio)-propionic acid ester; or 1,1'-ditidecyl 3,3'-thiodipropionic acid ester; and combinations thereof.

137. The method of claim 133, wherein the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-triacontylbis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphite; and combinations thereof.

138. The method of claim 112, wherein the passivating agent comprises a hydrazide or a triazole selected from the group consisting of dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

139. The method of claim 112, wherein the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

140. The method of claim 112, wherein the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes, and combinations thereof.

141. The method of claim 112, wherein the substrate wetting or dispersing agent comprises 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 nonionic surfactants, and combinations thereof.

142. The method of claim 112, wherein the tackifier comprises a hydrogenated hydrocarbon resin, an alicyclic hydrocarbon resin, and combinations thereof.

143. The method of claim 112, wherein the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalic acid esters, silicone oils, octyl epoxy esters, or hydrogenated light naphthenic petroleum distillates, and combinations thereof.

144. The method of claim 109, wherein the coating has a thickness of 25 nm to 500 μm.

145. The method of claim 109, wherein the at least one film-forming component comprising a water-based carrier is an aqueous emulsion or dispersion comprising the resin.

146. The method of claim 109, wherein the at least one film-forming component comprising an aqueous carrier does not contain any volatile organic solvents and is VOC-free.

147. The method of claim 145, wherein the aqueous emulsion or the aqueous dispersion comprises water in an amount of 50% to 70% by weight.

148. The method of claim 145, wherein the aqueous emulsion or the aqueous dispersion comprises the resin in an amount of 30% to 50% by weight.

149. The method of claim 109, wherein the resin comprises acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

150. The method of claim 109, wherein the low VOC composition further comprises a resin having a higher T g of additional resin.

151. The method of claim 150, wherein the additional resin has the same or different chemical nature as the resin.

152. The method of claim 151, wherein the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

153. The method of claim 109, wherein the at least one film-forming component comprises a blend of the resin and a self-crosslinking resin.

154. The method of claim 109, wherein the low VOC composition comprises a plasticizer in an amount of up to 40 weight percent.

155. The method of claim 109, wherein the low VOC composition has a volatile organic content of 100 g / L or less.

156. The method of claim 109, wherein the substrate comprises an electronic device.

157. The method of claim 109, wherein the film-forming components and associated additives exhibit viscoelastic, viscoplastic, or elasto-viscoplastic flow properties.

158. The method of claim 109, wherein the conformal film protects the substrate from one or more unwanted liquid or particulate contaminants, or a corrosive environment, or a combination thereof.

159. The method of claim 158, wherein the one or more liquids, particles, or combinations thereof include water, sweat or other moisture, dirt, dust, conductive metal particles, metal filings and other conductive particulate matter and chemicals, and combinations thereof.

160. The method of claim 109, wherein the low VOC composition is present as a multi-part system, each part having a subset of components, wherein each part of the multi-part system is capable of being applied to the substrate sequentially or simultaneously.

161. The method of claim 109, wherein the coating covers a male component, a female component, or both of a connector in the electronic device without adversely affecting the electrical properties of the printed circuit board.

162. The method of claim 109, wherein the coating, when applied to the substrate, reduces the force required to insert and mate a connector.

163. The method of claim 109, wherein the substrate is partially coated or entirely coated.

164. The method of claim 109, wherein the coating is deposited on different components of the printed circuit board based on desired environmental protection.

165. The method of claim 109, wherein the coating is deposited on the substrate to achieve a film thickness of 25 nm to 500 μm.

166. The method of claim 109, wherein one of the components in the coating evaporates such that the coating is deformable during evaporation and is non-deformable after evaporation.

167. The method of claim 109, wherein one of the components in the coating is crosslinked such that the coating is deformable during crosslinking and is indeformable after crosslinking.

168. A coating configured to protect a substrate from unwanted contaminants, the coating comprising: A low VOC composition comprising: at least one film-forming component; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

169. A coating according to claim 168, wherein the coating is deformable and electrically insulating when applied to the substrate.

170. The coating of claim 168, wherein the coating is used as a friction reducing coating on the substrate.

171. A coating according to claim 168, wherein the at least one additive comprises a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

172. The coating of claim 168, wherein the at least one additive is present in the composition in an amount of 0.001 wt. % to 40 wt. %.

173. The coating of claim 171, wherein the filler comprises functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, or cellulose-based particles, and combinations thereof.

174. The coating of claim 171, wherein the plasticizer comprises a polymer plasticizer, a benzoate plasticizer, and a phthalate plasticizer.

175. The coating of claim 174, wherein the benzoate plasticizer comprises diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

176. The coating of claim 174, wherein the polymeric plasticizer comprises poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, bio-based alkyd resins, and combinations thereof.

177. The coating of claim 171, wherein the initiator comprises difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

178. The coating of claim 171, wherein the defoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent, and combinations thereof.

179. The coating of claim 171, wherein the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, and combinations thereof.

180. The coating of claim 171, wherein the hydrophobic agent comprises paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

181. The coating of claim 171, wherein the biocide comprises isothiazolinone, formaldehyde-releasing biocide (FA-R), carbamate-containing fungicide, and combinations thereof.

182. The coating of claim 171, wherein the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

183. The coating of claim 171, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

184. The coating of claim 171, wherein the substrate wetting agent comprises silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

185. The coating of claim 171, wherein the dye comprises a distyryl compound, a distyryl biphenyl derivative, a benzoxazole, and combinations thereof.

186. The coating of claim 171, wherein the crosslinking agent comprises zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether-based crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and combinations thereof.

187. The coating of claim 171, wherein the pigment comprises an organic pigment, an inorganic pigment, and combinations thereof.

188. The coating of claim 171, wherein the dispersant comprises fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

189. The coating of claim 171, wherein the adhesion promoter comprises silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

190. The coating of claim 171, wherein the coalescing agent comprises glycol ethers, ester alcohols, and combinations thereof.

191. The coating of claim 171, wherein the UV absorber or stabilizer comprises hydroxy-phenyl-benzo-triazole, hydroxy-phenyl-triazine, hydroxy-benzophenone, sterically hindered amines, and combinations thereof.

192. The coating of claim 171, wherein the preservative comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

193. The coating of claim 171, wherein the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, and combinations thereof.

194. The coating of claim 193, wherein the phenolic antioxidant is selected from the group consisting of octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction mass: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid C7-9 alkyl esters; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)ester; or the reaction products of 4-methylphenol with dicyclopentadiene and isobutylene and combinations thereof.

195. A coating according to claim 193, wherein the amine antioxidant is selected from the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

196. A coating according to claim 193, wherein the thioether antioxidant is selected from 3-(dodecylthio)-propionic acid 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or 3,3'-thiodipropionic acid 1,1'-ditidecyl ester; and combinations thereof.

197. A coating according to claim 193, wherein the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-triacontylbis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphite; and combinations thereof.

198. A coating according to claim 171, wherein the passivating agent comprises a hydrazide or a triazole selected from dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

199. The coating of claim 171, wherein the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

200. The coating of claim 171, wherein the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes, and combinations thereof.

201. A coating according to claim 171, wherein the substrate wetting agent or dispersant comprises 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 nonionic surfactants, and combinations thereof.

202. The coating of claim 171, wherein the adhesion promoter comprises a hydrogenated hydrocarbon resin, an alicyclic hydrocarbon resin, and combinations thereof.

203. The coating of claim 171, wherein the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalic acid esters, silicone oils, octyl epoxy esters, or hydrogenated light cycloalkyl petroleum distillates, and combinations thereof.

204. The coating of claim 168, wherein the conformal film has a thickness of 25 nm to 500 μm, 205. The coating of claim 168, wherein the at least one film-forming component comprising a water-based carrier comprises an aqueous emulsion or dispersion.

206. The coating of claim 205, wherein the aqueous emulsion or the aqueous dispersion comprises water in an amount of 50% to 70% by weight.

207. The coating of claim 205, wherein the aqueous emulsion or the aqueous dispersion comprises the resin in an amount of 30% to 50% by weight.

208. The coating of claim 168, wherein the water-based carrier does not contain any volatile organic solvents and is VOC-free.

209. The coating of claim 168, wherein the resin is selected from the group consisting of acrylics, styrene-acrylics, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

210. The coating of claim 168, further comprising a resin having a higher T than the first resin. g of additional resin.

211. A coating according to claim 210, wherein the additional resin has the same or different chemical nature as the first resin.

212. The coating of claim 211, wherein the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

213. The coating of claim 168, wherein the at least one film-forming component comprises a blend of the resin and a self-crosslinking resin.

214. The coating of claim 171, wherein the composition comprises a plasticizer in an amount of up to 40 wt%.

215. The coating of claim 168, wherein the composition has a volatile organic content of 100 g / L or less.

216. The coating of claim 168, wherein the composition is free of volatile organic compounds.

217. The coating of claim 168, wherein the at least one undesirable contaminant comprises one or more of liquids, solids, gases, and combinations thereof.

218. The coating of claim 168, wherein the at least one undesirable contaminant comprises water, sweat or other moisture, dirt, dust, conductive metal particles, metal shavings and other conductive particulate matter and chemicals, and combinations thereof.

219. A substrate comprising a low VOC coating, wherein the low VOC coating comprises: A low VOC composition comprising: at least one film-forming component; and at least one additive, wherein the at least one film-forming component comprises a resin present in a sufficient amount and configured to form a glass transition temperature (T g ) below 25°C conformal film.

220. The substrate of claim 219, wherein the at least one film-forming component comprises an aqueous carrier.

221. A substrate according to claim 219, wherein the at least one additive comprises a filler, a plasticizer, an initiator, a defoamer, a surfactant, an antioxidant, a hydrophobic agent, a biocide, a leveling agent, a substrate wetting agent, a crosslinking agent, a dye, a pigment, a dispersant, a passivator, a tackifier, a coalescing agent or solvent, a rheology modifier, a UV absorber or stabilizer, and a preservative.

222. A substrate according to claim 219, wherein the at least one additive is present in the composition in an amount of 0.001 wt. % to 40 wt. %.

223. A substrate according to claim 221, wherein the filler comprises functionalized fumed silica, unfunctionalized fumed silica, precipitated silica, silica nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles or cellulose-based particles and combinations thereof.

224. The substrate of claim 221, wherein the plasticizer comprises a polymer plasticizer, a benzoate plasticizer, and a phthalate plasticizer.

225. The substrate of claim 224, wherein the benzoate plasticizer comprises diethylene glycol dibenzoate, dipropylene glycol dibenzoate, propylene glycol dibenzoate, and combinations thereof.

226. The substrate of claim 224, wherein the polymeric plasticizer comprises poly[oxy(methyl-1,2-ethanediyl)], alpha-(methylphenyl)-omega-hydroxy, bio-based alkyd resins, and combinations thereof.

227. The substrate of claim 221, wherein the initiator comprises difunctional or multifunctional α-hydroxy ketones, acylphosphine oxides, benzoylformates, benzophenones, zinc oxide nanoparticles, peroxides, azo compounds, and combinations thereof.

228. The substrate of claim 221, wherein the defoaming agent comprises silicone oil, mineral oil, vegetable oil, polar oil, molecular defoaming agent, hydrophobic nanoparticles, emulsifier, solvent, and combinations thereof.

229. The substrate of claim 221, wherein the surfactant comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, and combinations thereof.

230. The substrate of claim 221, wherein the hydrophobic agent comprises paraffin wax emulsion, modified paraffin wax, paraffin wax / polyethylene wax emulsion, silicone resin, and combinations thereof.

231. The substrate of claim 221, wherein the biocide comprises isothiazolinone, formaldehyde-releasing biocide (FA-R), carbamate-containing fungicide, and combinations thereof.

232. The substrate of claim 221, wherein the rheology modifier comprises a hydrophobically modified ethoxylated urethane (HEUR) type thickener, an alkali swellable emulsion, an acrylic copolymer, and combinations thereof.

233. The substrate of claim 221, wherein the leveling agent comprises silicone, liquid polyacrylate, ionic surfactant, nonionic surfactant, fluorosurfactant, and combinations thereof.

234. The substrate of claim 221, wherein the substrate wetting agent comprises silicone, a multifunctional surfactant, a polyethylene glycol ether, a modified polyethylene glycol ether, and combinations thereof.

235. The substrate of claim 221, wherein the dye comprises a distyryl compound, a distyryl biphenyl derivative, a benzoxazole, and combinations thereof.

236. A substrate according to claim 221, wherein the crosslinking agent comprises zinc ammonium carbonate solution, carbodiimide crosslinking agent, melamine crosslinking agent, aziridine crosslinking agent, monofunctional or polyfunctional aliphatic glycerol polyglycidyl ether crosslinking agent, monofunctional or polyfunctional aliphatic epoxy resin, ethylene glycol diglycidyl ether, oxazoline reactive polymer, polyol, polyisocyanate, methacrylamide, dihydrazide crosslinking agent, organofunctional silane, metal complex, UV sensitive functional monomer and their combination.

237. The substrate of claim 221, wherein the pigment comprises an organic pigment, an inorganic pigment, and combinations thereof.

238. The substrate of claim 221, wherein the dispersant comprises fatty acid modified polyesters, sodium salts of acrylic acid polymers, ammonium salts of hydrophobic copolymers, modified polyacrylates, zwitterionic surfactants, and combinations thereof.

239. The substrate of claim 221, wherein the adhesion promoter comprises silanes, ethylene copolymers, hydroxyl functional copolymers, and combinations thereof.

240. The substrate of claim 221, wherein the coalescing agent comprises glycol ethers, ester alcohols, and combinations thereof.

241. The substrate of claim 221, wherein the UV absorber or stabilizer comprises hydroxy-phenyl-benzo-triazole, hydroxy-phenyl-triazine, hydroxy-benzophenone, sterically hindered amines, and combinations thereof.

242. The substrate of claim 221, wherein the preservative comprises an organic acid amine complex, zinc phosphate, and combinations thereof.

243. The substrate of claim 221, wherein the antioxidant comprises a phenolic antioxidant, an amine antioxidant, a thioether antioxidant, a phosphite antioxidant, a lactone, and combinations thereof.

244. A substrate according to claim 243, wherein the phenolic antioxidant is selected from octadecyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; 2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoate; isomers of the following substances in reaction mass: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid C7-9 alkyl esters; 1,3,5-tri{[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)ester; or the reaction products of 4-methylphenol with dicyclopentadiene and isobutylene and combinations thereof.

245. A substrate according to claim 243, wherein the amine antioxidant is selected from the reaction product of N-phenylaniline and 2,4,4-trimethylpentene; N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthylamine; 4,4'-dioctyldiphenylamine; other alkylated amines and combinations thereof.

246. A substrate according to claim 243, wherein the thioether antioxidant is selected from 3-(dodecylthio)-propionic acid 1,1'-[2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl] ester; or 3,3'-thiodipropionic acid 1,1'-ditidecyl ester; and combinations thereof.

247. A substrate according to claim 243, wherein the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl)phosphite; butylene bis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P',P'-tricarboxylic bis(phosphine); 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphite; and combinations thereof.

248. A substrate according to claim 221, wherein the passivating agent comprises a hydrazide or a triazole selected from dodecanedioic acid 1,12-bis[2-(2-hydroxybenzoyl)hydrazide]; 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropanoic acid 2-[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]hydrazide; 2-hydroxy-N-(1H-1,2,4-triazol-3-yl)benzamide-1,2,4-triazole; N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methylamine; and combinations thereof.

249. The substrate of claim 221, wherein the rheology modifier comprises sodium polyacrylate, polyamide wax, polyethylene wax, hydrogenated castor oil, attapulgite clay, fumed silica, precipitated silica, metal oxide particles, and combinations thereof.

250. A substrate according to claim 221, wherein the adhesion promoter comprises chlorinated polyolefins, cyanoacrylate primers, polyester alkyl ammonium salts, amino functional polyethers, maleic anhydride, carboxylated polypropylene, glycidyl methacrylate functionalized polyolefins, trimethoxyvinyl silane, silanes and combinations thereof.

251. A substrate according to claim 221, wherein the substrate wetting or dispersing agent includes 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.

252. The substrate of claim 221, wherein the adhesion promoter comprises a hydrogenated hydrocarbon resin, an alicyclic hydrocarbon resin, and combinations thereof.

253. A substrate according to claim 221, wherein the plasticizer comprises hydrogenated alicyclic hydrocarbon resins, trimellitic acid esters, high molecular weight phthalic acid esters, silicone oils, octyl epoxy esters or hydrogenated light cycloalkyl petroleum distillates and combinations thereof.

254. The substrate of claim 219, wherein the conformal film has a thickness of 25 nm to 500 μm.

255. The substrate of claim 220, wherein the water-based carrier comprises an aqueous emulsion or dispersion.

256. The substrate of claim 255, wherein the aqueous emulsion or the aqueous dispersion comprises water in an amount of 50% to 70% by weight.

257. The substrate of claim 255, wherein the aqueous emulsion or the aqueous dispersion comprises the resin in an amount of 30% to 50% by weight.

258. A substrate according to claim 219, wherein the water-based carrier does not contain any volatile organic solvents and is VOC-free.

259. The substrate of claim 219, wherein the resin is selected from the group consisting of acrylic resins, styrene-acrylic resins, silicones, polyurethanes, styrene-butadiene, acrylonitrile-butadiene, and combinations thereof.

260. The substrate of claim 219, further comprising a resin having a higher T than the first resin. g of additional resin.

261. A substrate according to claim 260, wherein the additional resin has the same or different chemical nature as the first resin.

262. The substrate of claim 261, wherein the additional resin comprises an alkyd resin, a vinyl acrylic resin, or a vinyl acetate-ethylene copolymer.

263. A substrate according to claim 219, wherein the at least one film-forming component comprises a blend of the resin and a self-crosslinking resin.

264. A substrate according to claim 219, wherein the composition comprises a plasticizer in an amount of up to 40 weight percent.

265. The substrate of claim 219, wherein the composition has a volatile organic content of 100 g / L or less.

266. A substrate according to claim 219, wherein the composition does not contain volatile organic compounds.

267. A substrate according to claim 219, wherein the at least one undesirable contaminant comprises one or more liquids, solids, gases, and combinations thereof.

268. A substrate according to claim 219, wherein the at least one undesirable contaminant includes water, sweat or other moisture, dirt, dust, conductive metal particles, metal filings and other conductive particulate matter and chemicals, and combinations thereof.

269. The substrate of claim 219, wherein the substrate comprises an automotive part or a consumer electronic device.

270. The substrate of claim 219, wherein the conformal film is deformable and electrically insulating when applied to the substrate.